Multivariate Analysis of Risk Factors for Complications in Pediatric Tissue Expansion

BACKGROUND

Tissue expanders represent one of the main surgical options for skin reconstruction in cases of tumors, traumalike burn injury, scar contracture, and alopecia. However, the tissue expander device is also associated with complications such as infection and extrusion. The aim of this study was to analyze risk factors for major complications of use of tissue expanders in pediatric patients using multivariate analysis.

METHODS

A retrospective, single-center observational study was performed over 10 years in pediatric patients who were treated with tissue expanders for tumors, nevus, scars, burn reconstruction, and alopecia from April 2012 to March 2022. The primary outcome was overall complications per operation and expander, including infection and extrusion. Ten predictor variables were included as risk factors based on previous studies and as new factors considered important from clinical experience. Univariate and multivariate logistic regression analyses were performed to identify risk factors for major complications such as expander infection or extrusion.

RESULTS

The study included 44 patients who underwent 92 operations using 238 tissue expanders. The overall complication rate per expander was 14.3%. Univariate logistic regression analysis identified associations of younger age, number of expanders used per operation, history of infection, and tissue expander locations with a higher complication rate. In multivariate logistic regression analysis, younger age (odds ratio, 1.14; P = 0.043) was associated with a high likelihood of expander complications.

CONCLUSIONS

Younger age is an independent risk factor for tissue expander complications in pediatric patients. This factor should be considered in preoperative planning and discussions with the patient's family.

Fecal DNA analysis coupled with the sighting records re-expanded a known distribution of dugongs in Ryukyu Islands after half a century

DNA analysis of large herbivore feces samples collected from seagrass beds at two distant sites (Irabu Island in Miyako Islands and Kushi in Okinawa Island) in the Ryukyu Islands proved that some of these feces were from dugongs, which had been treated in recent studies as extinct in this region since the last stranding of a deceased individual in 2019. In addition, local knowledge of sightings of animals thought to be dugongs and confirmed cases of dugong feeding trails since 2010 were compiled to estimate its recent distribution. This is the first scientific report on the presence of this mammal in the Ryukyu Islands within the last four years, and particularly in the Miyako Islands within the last half-century. As the Ryukyu Islands are known to be the northern limit of the dugong's fragmented distribution in East Asia, conservation efforts are therefore needed.

Repeated Fluid Accumulation around a Breast Implant Related to Synovial Metaplasia of the Capsule

We must take special care when treating postoperative fluid accumulation around breast implants (BIs) to exclude any serious complications, including BI-associated anaplastic large cell lymphoma. However, most late-onset fluid accumulation is caused by other conditions, such as traumatic hematoma and residual postoperative seroma. Surgeons must choose whether to conservatively observe or remove such BIs, while also determining whether to perform partial capsulectomy or total capsulectomy to solve the problem of fluid accumulation. We treated a 72-year-old woman who noticed swelling in her right breast 4 years after undergoing bilateral BI reconstruction. Before she was referred to our hospital, the fluid had been drained by needle aspiration five times, but the swelling returned to a similar size within a month. No malignant findings were observed by needle-aspirated cytology or flow cytometry. The patient requested the simultaneous removal of the left BI. Therefore, we performed both BI removal with total capsulectomy on the right side and partial capsulectomy of the superficial layer on the left side. A pathological examination of the capsule on the right side indicated a chronic expanding hematoma and synovial metaplasia characterized by papillary projections rich in CD68-positive cells, thus indicating reactive synovial cells. In contrast, the left superficial capsule was much thinner and showed less synovial metaplasia. Our findings indicate the advantages of total capsulectomy to solve the problem of repeated serous fluid accumulation around BIs, according to histological changes in the capsule.

Comparative evaluation for the performance of environmental DNA and RNA analyses targeting mitochondrial and nuclear genes from ayu (Plecoglossus altivelis)

Environmental DNA and RNA (eDNA and eRNA; collectively eNA) analyses have the potential for non-invasive and cost-efficient biomonitoring compared with traditional capture-based surveys. Although various types of eNA particles, including not only mitochondrial eDNA but also nuclear eDNA and their transcripts, are present in the water, performances of eNA detection and quantification have not yet been evaluated sufficiently across multiple mitochondrial and nuclear genes. We conducted a tank experiment with ayu (Plecoglossus altivelis) to compare the detection sensitivity, yields per water sample, and quantification variability between replicates of each type of eNAs. The assay targeting the multi-copy nuclear gene exhibited a higher sensitivity than the assay targeting the mitochondrial gene, and both the target eDNA and eRNA concentrations per water sample were higher for the nuclear gene. On the contrary, variation in eRNA quantifications per sample does not necessarily correspond to that in eDNA, and the intra-sample quantification variability (represented as the CVs between PCR replicates) tended to be larger for eRNA than eDNA. Our results suggested that, even if suitable to the sensitive detection of species occurrence, the use of eRNA particularly derived from multi-copy nuclear gene may not be necessarily appropriate for the reliable assessment of species abundance. The findings in this study would help optimize eNA analyses for making biomonitoring and stock assessment in aquatic environments more efficient and reliable.

COX2 expression plays a role in spinal cord injury-induced neuropathic pain

BACKGROUND CONTEXT

Elucidating the mechanism of neuropathic pain (NeP) is crucial as it can result in motor dysfunction and negatively impact quality of life in patients with spinal cord injury (SCI). Although it has been reported that cyclooxygenase 2 (COX2) is involved in NeP in rat models of peripheral nerve injury and that COX2 inhibitors can alleviate NeP, these mechanisms after SCI have not been fully investigated.

PURPOSE

The purpose is to investigate whether the thoracic SCI affects the expression of mRNAs for COX1 and COX2 in the lumbar spinal cord, and the effect of COX2 inhibitor on its behavior.

STUDY DESIGN

Male Sprague-Dawley (SD) rats underwent thoracic (T10) spinal cord contusion injury using an Infinite Horizon (IH) impactor device. SCI rats received COX2 inhibitors (50 μg/day) on days 5 and 6 after SCI.

METHODS

Male SD rats underwent T10 laminectomy under mixed anesthesia, and IH impactors were applied to the same site to create a rat SCI model. Rats that underwent only laminectomy were designated as sham. Lumbar spinal cord at the L4-5 level was harvested at 3, 5, 7, 14, and 28 days after SCI, and COX2 and COX1 were quantified by reverse-transcription PCR (RT-PCR). COX2 expression, expression site, and expression time were determined by immunohistochemistry (IHC) and in situ hybridization histochemistry (ISHH) at the same time points. The expression site and time of COX2 expression were also examined at the same time point by ISHH. On 5th and 6th day after SCI, saline and COX2 inhibitor (50 μg/day) were administered into the subarachnoid space as a single dose, and the two groups were compared in terms of mechanical withdrawal latency using the dynamic plantar esthesiometer, which is an automated von Frey-type system.

RESULTS

COX2 was significantly increased at 5 and 7 days after SCI, but no significant difference in COX1 was observed after SCI by RT-PCR. ISHH targeting COX2 showed clear expression of COX2 in spinal cord vascular endothelial cells at 5 and 7 days after SCI. COX2 expression was almost abolished at day 14 and 28. Behavioral experiments showed that pain was significantly improved from day 2 after COX2 inhibitor administration compared to the saline group, with improvement up to day 14 after SCI, but no significant difference was observed after day 21.

CONCLUSIONS

The present findings suggest that thoracic SCI increased COX2 in vascular endothelial cells in the lumbar spinal cord and that the administration of COX2 inhibitor significantly alleviated mechanical hypersensitivity of the hind-paw following the thoracic SCI. Therefore, endothelial cell derived COX2 in the lumbar spinal cord may be involved in the induction of neuropathic pain in the SCI model rats.

CLINICAL SIGNIFICANCE

The findings in the present study regarding the induction of endothelial COX2 and the effect of its inhibitor on the mechanical hypersensitivity suggest that endothelial cell-derived COX2 is one of the focuses for the treatment for neuropathic pain in the acute phase of SCI.

Long term observation of de novo adipogenesis using novel bioabsorbable implants with larger size in a porcine model

Introduction

The regeneration of adipose tissue in patients after breast cancer surgery would be desirable without the use of growth factors or cells to avoid potential recurrence and metastasis. We reported that prolate spheroidal-shaped poly-L-lactic acid (PLLA) mesh implants of approximately 18-mm polar diameter and 7.5-mm greatest equatorial diameter containing collagen sponge (CS) would be replaced by regenerated adipose tissue after implantation, thereby suggesting an innovative method for breast reconstruction. Our study aimed to evaluate the adipose tissue regeneration ability of implant aggregates in a porcine model.

Methods

We prepared implant aggregates consisting of thirty PLLA mesh implants containing CS packed in a woven poly (glycolic acid) bag. The implant aggregates were inserted under the mammary glands in the porcine abdomen for a year. Single and double groups were classified by inserting either one or two implant aggregates on each side of the abdomen, respectively.

Results

In both groups, the volume of the implant aggregates decreased over time, and the formation of adipose tissue peaked between 6 and 9 months. Histologically, the formation of adipose tissue was confirmed in the area that was in contact with native adipose tissue.

Conclusions

Our implant aggregates could induce the autologous adipose tissue after long term implantation in vivo, without the use of any growth factor or cell treatment, presenting a potential novel method of breast reconstruction.

A high-hydrostatic pressure device for nevus tissue inactivation and dermal regeneration for reconstructing skin defects after giant congenital melanocytic nevus excision: a clinical trial

Background

A novel treatment has been developed to reconstruct large skin defects caused by the excision of giant congenital melanocytic nevi. It involves the reimplantation of high-hydrostatic pressurized nevus tissue as a cell-inactivated autologous scaffold for dermal regeneration, followed by the implantation of cultured epithelial autografts on the regenerated dermis. Because this treatment has shown promise in a first-in-human clinical trial which used a prototype pressure machine, a novel pressure device was specifically designed for clinical use.

Methods

In a prospective investigator-initiated clinical trial involving three patients, we evaluated the safety and efficacy of the skin regeneration treatment using a pressure device. All three patients underwent surgical excision of the nevus tissue, primary reimplantation of the inactivated nevus tissue, and secondary implantation of cultured epithelial autografts.

Results

Engraftment of inactivated nevus tissue and cultured epithelial autografts was successful in all three cases, with over 90% epithelialization at 8 weeks post-surgery. No serious adverse events or device malfunction were observed during the trial.

Conclusion

The novel pressure device safely and effectively enabled dermal regeneration using the nevus tissue as an autologous scaffold. This innovative approach offers several advantages, including reduced invasiveness due to minimal sacrifice of normal skin for skin grafting and high curative potential resulting from full-thickness removal of the nevus tissue.

Development of new bioabsorbable implants with de novo adipogenesis

Poly-L-lactic acid (PLLA) mesh implants containing collagen sponge (CS) were replaced with autologous adipose tissue regeneration in vivo. Herein, we investigated the optimal external frames and internal fillings using poly (lactic-co-ε-caprolactone) (P (LA/CL)), PLLA, and low-molecular-weight PLLA (LMW-PLLA) as the external frame and polyglycolic acid (PGA) nanosheets and CS as the internal filling. We prepared six implants: P (LA/CL) with PGA nano, PLLA with PGA nano, PLLA with CS, PLLA with 1/2 CS, PLLA with 1/4 CS, and LMW-PLLA with CS, and evaluated adipogenesis at 6 and 12 months using a rat inguinal model. The internal spaces in the P (LA/CL) and LMW-PLLA implants collapsed at 6 months, whereas those in the other four implants collapsed at 12 months. Adipose tissue regeneration was not significantly different between the PLLA-implanted groups at 6 and 12 months and was greater than that in the P (LA/CL) with PGA nano and LMW-PLLA with CS groups. The PGA nanosheet inside PLLA was comparable to the CS inside PLLA in the regeneration of adipose tissue and macrophage infiltration. In summary, PLLA is a promising external frame material in which the internal space can be replaced with adipose tissue. Thus, PGA nanosheets are an alternative internal filling material for adipose tissue regeneration.

Comparisons of the effects of silk elastin and collagen sponges on wound healing in murine models

Introductions

Silk elastin, a recombinant protein with repeats of elastin and silk fibroin, possesses a self-gelling ability and is a potential wound dressing material. The aim of this study is to elucidate the mechanism of the wound healing-promoting effect of silk elastin by comparing its in vivo behavior in a mouse wound model with that of a collagen sponge.

Methods

Skin defects (8 mm in diameter) were created on the backs of C57BL/6J and BKS.Cg- + Lepr/+Lepr db male mice. Silk elastin sponges of 2.5 or 5.0 mm thickness, as well as collagen sponges, were placed on the wounds and secured with a polyurethane film. In the control group, only the polyurethane film was applied. The remaining wound area was grossly evaluated, and tissue samples were collected after 7, 14, and 21 days for histological evaluation, including neoepithelialization, wound contraction, granulation tissue formation, newly formed capillaries, and macrophages. Genetic analysis was conducted using real-time polymerase chain reaction.

Results

In the study with C57BL/6J, there were no significant differences between the silk elastin and collagen sponge groups. Similarly, in the study using BKS.Cg- + Lepr/+Lepr db, no significant differences were found in the remaining wound area and granulation tissue formation between the silk elastin and collagen sponge groups. However, on day 14, the 5.0-mm-thick silk elastin sponge group showed increased macrophages, longer neoepithelialization, and more frequent angiogenesis compared to other groups. Gene expression of inducible nitric oxide synthase and arginase-1 was also higher in the 5.0 mm thick silk elastin sponge group.

Conclusions

Silk elastin sponges demonstrated superior neoepithelialization and angiogenesis compared to collagen sponges. The results suggest that silk elastin and collagen sponges promote wound healing through different mechanisms, with silk elastin possibly enhancing wound healing by facilitating increased macrophage migration. Further studies are needed, but silk elastin shows great potential as a versatile wound dressing material.

Interposition grafting of collagen-gelatin sponge impregnated with basic fibroblast growth factor in primary palatoplasty

INTRODUCTION

An oronasal fistula is a challenging post-operative complication of palatoplasty due to impaired velopharyngeal function or its high recurrence rate. Muscle repositioning, a key procedure in palatoplasty, causes dead space at the junction between the hard and soft palates. Consequently, thin oral and nasal mucosae are prone to break down and form fistulas. In this study, we used basic fibroblast growth factor-impregnated collagen gelatin sponge (bFGF-CGS) in primary palatoplasty to reduce fistula formation.

METHODS

This retrospective study assessed the complications and efficacy of bFGF-CGS to reduce fistula formation. Patients who underwent primary palatoplasty with bFGF-CGS were included. The same number of patients who underwent primary palatoplasty without bFGF-CGS was included as a control group. The outcomes included post-operative oronasal fistula formation, delayed healing, bleeding, and infection.

RESULTS

Both groups included 44 patients. Except for age at palatoplasty, there were no statistically significant demographic differences between the two groups; however, the rates of fistula formation in the study and control group were 2.3% and 13.6%, respectively. There were no infections among the patients.

CONCLUSIONS

The grafting of bFGF-CGS in primary palatoplasty was safe and probably effective in reducing post-operative oronasal fistula formation.

An easy-to-use semi-automatic volumetric evaluation for secondary bone grafting in patients with unilateral alveolar cleft

Surgical intervention for alveolar bone formation is important in patients with alveolar cleft; however, the treatment methods and materials are still controversial. A precise evaluation method for postoperative bone formation is important for comparing outcomes and establishing the best treatment protocol. The purpose of this study is to establish a new method of evaluating surgical outcomes for patients with alveolar cleft. Computed tomography datasets from 20 patients who underwent secondary alveolar bone grafting were obtained before and 1 year after surgery. Six anatomical landmarks were used to superimpose the preoperative and mirrored preoperative volume and postoperative volume data. The cleft region was segmented by subtracting the preoperative from mirrored preoperative volume data, and the failed osteogenesis region was segmented by subtracting the postoperative volume data from the cleft region; subsequently, the bone formation ratio was calculated. Two observers performed this method using a free software 3D slicer and the average evaluation times were 12.7 and 13.2 min for observers 1 and 2, respectively. Method reliability was determined by evaluating intraclass correlation coefficients. The intra-observer intraclass correlation coefficients were 0.97 and 0.96 for observers 1 and 2, respectively. The inter-observer intraclass correlation coefficient was 0.97. Our method is practical for assessing bone formation after treatment, which does not require specific knowledge or software and can be used by ordinary physicians.

Development of a Self-Assembled Dermal Substitute from Human Fibroblasts Using Long-term Three-Dimensional Culture

Skin substitutes have emerged as an alternative to autografts for the treatment of skin defects. Among them, scaffold-based dermal substitutes have been extensively studied; however, they have certain limitations, such as delayed vascularization, limited elasticity, and the inability to achieve permanent engraftment. Self-assembled, cell-based dermal substitutes are a promising alternative that may overcome these shortcomings but have not yet been developed. In this study, we successfully developed a cell-based dermal substitute (cultured dermis) through the long-term culture of human dermal fibroblasts using the net-mold method, which enables three-dimensional cell culture without the use of a scaffold. Spheroids prepared from human dermal fibroblasts were poured into a net-shaped mold and cultured for 2, 4, or 6 months. The dry weight, tensile strength, collagen and glycosaminoglycan levels, and cell proliferation capacity were assessed and compared among the 2-, 4-, and 6-month culture periods. We found that collagen and glycosaminoglycan levels decreased over time, while the dry weight remained unchanged. Tensile strength increased at 4 months, suggesting that remodeling had progressed. In addition, the cell proliferation capacity was maintained, even after a 6-month culture period. Unexpectedly, the internal part of the cultured dermis became fragile, resulting in the division of the cultured dermis into two collagen-rich tissues, each of which had a thickness of 400 μm and sufficient strength to be sutured during in vivo analysis. The divided 4-month cultured dermis was transplanted to skin defects of immunocompromised mice and its wound healing effects were compared to those of a clinically available collagen-based artificial dermis. The cultured dermis promoted epithelialization and angiogenesis more effectively than the collagen-based artificial dermis. Although further improvements are needed, such as the shortening of the culture period and increasing the size of the cultured dermis, we believe that the cultured dermis presented in this study has the potential to be an innovative material for permanent skin coverage.

Preoperative Mohs Paste Treatment for a Subcutaneous Sarcoma and a Skin Ulcer to Prevent Intraoperative Bleeding

Introduction

Mohs paste has a zinc chloride component and the ability to coagulate tissue. Mohs chemosurgery or surgery is a method by which coagulated tissue is removed and can be repeated until the tumor disappears. The palliative purpose of Mohs chemosurgery or surgery is to control bleeding or exudate from a malignancy with a skin ulcer. In the current report, a single application of Mohs paste as a pre-operative treatment for a superficial sarcoma with a skin ulcer prevented intra-operative bleeding.

Case Report

Two metastatic sarcomas are described: one in the scalp originating from a rectoperineal dedifferentiated liposarcoma and one in the elbow originating from a humeral telangiectatic osteosarcoma. Mohs paste treatment was performed the day before surgical resection. The Mohs paste procedure successfully prevented intra-operative bleeding from the tumor, leading to easy removal of the tumors with appropriate tumor-free margins.

Conclusion

Preoperative Mohs paste treatment is a simple and reliable method. Intra-operative neoplastic bleeding may contaminate the tumor cells within the surgical field; thus the prevention of bleeding with Mohs paste treatment may lead to a decrease in the tumor recurrence rate.

Flap Viability Evaluation Using a Tissue Oximetry Camera as an Alternative to Indocyanine Green Fluorescence Imaging

Indocyanine green (ICG) fluorescence imaging is useful for assessing flap viability; however, it is associated with a risk of anaphylactic shock, even in patients with no history of drug allergies. SnapshotNIR is a noncontact, camera-type handheld tissue oximeter that can measure the tissue oxygen saturation of the body surface. The device emits red and near infrared light wavelengths and then optimizes the measurement of the differential reflectance from oxygenated and deoxygenated hemoglobin, and StO2 is calculated. A 20 × 15 cm surgical field can be evaluated in less than 3 seconds by holding the camera at a distance of 30 cm. We applied this device at zone II in a deep inferior epigastric perforator (DIEP) flap, and compared the findings with the border of flap perfusion detected by ICG imaging. Left breast reconstruction using a free DIEP flap was performed for a 60-year-old woman. The DIEP flap was vascularized by a perforator vessel coursing to the right abdominis muscle. First, Diagnogreen (5 mg; Daiichi Sankyo Co., Tokyo, Japan) was intravenously injected, and the ICG fluorescence perfusion border detected by PDE-neo (Hamamatsu Photonics, Hamamatsu City, Shizuoka, Japan) was determined. The ICG border was defined by two reconstructive surgeons after fluorescence had spread out for 2 minutes. Next, zones Ⅱ and Ⅳ of the DIEP flap, contralateral to the perforator, were evaluated using photographs obtained by SnapshotNIR. There were significant StO2 value differences between the ICG-negative area and ICG-positive area. This device can be widely applied in the noninvasive evaluation of flap viability.

A novel approach for wound treatment using dried cultured epidermal allograft: A phase I/II, single-center, open-label clinical trial

BACKGROUND

Autologous cultured epidermis (CE) is successfully used in burn care, but it requires a manufacturing time of three weeks and is very expensive owing to its custom-made nature of treatment. To compensate this disadvantage, dried allogeneic CE promises a novel therapeutic approach; and previous reports have demonstrated its efficacy in promoting wound healing using a murine skin defect model. Herein, a prospective clinical study was conducted to confirm the safety and efficacy of dried allogeneic CE for wound treatment.

METHODS

Dried CE was manufactured using donor keratinocytes obtained from excess surgical skin and applied to skin defects that were at least 3 cm in length and less than 10 % of the body surface area of the patients. The patients were observed for 14 days after CE application. The primary endpoint was the incidence of adverse events and the secondary endpoint was the percentage of wound healed since baseline, on days 7 and 14. Furthermore, as a stratified analysis, the percentage of wound healed, specified as deep dermal burns, was calculated.

RESULTS

Six patients (five burns and one skin ulcer after necrotizing fasciitis) enrolled in the study. As a serious adverse event, a local infection was observed in one patient, which resolved by debridement and conventional skin grafting. Other adverse events that were potentially related to this treatment included two cases of skin erosion, and one case of systemic fever. No unresolved adverse events remained at the end of the study period. The percentage of wound healed was 73.4 ± 19.2 % on Day 7, and 92.2 ± 11.8 % on Day 14. When the targeted disease was restricted to deep dermal burns, the percentage of wound healed was 69.9 ± 28.9 % on Day 7 and 90.5 ± 13.2 % on Day 14.

CONCLUSION

Treatment with dried CE was safely performed without any unresolved severe adverse effects. Dried CE is a new and promising modality for skin defect treatment, such as burns and ulcers, and is expected to compensate for the disadvantages of autologous CE. However, large-scale clinical trials are required to confirm their efficacy.

Modified gelatin hydrogel nonwoven fabrics (Genocel) as a skin substitute in murine skin defects

Introduction

From previous research, an emerging material composed of gelatin hydrogel nonwoven fabric (Genocel) has shown potential as a skin substitute, by improving neovascularization promotion in the early phase of wound healing. However, Genocel was inferior in terms of granulation formation compared to Pelnac. To solve this problem, we modified the manufacturing process of Genocel to reduce its water content, extend the degradation time (Genocel-L), and evaluate its healing process as a skin substitute.

Methods

Genocel with a low water content (Genocel-L) was prepared and the difference in water content compared to that of the conventional Genocel was confirmed. Degradation tests were performed using collagenase and compared among Genocel-L, Genocel, and Pelnac sheets. In the in vivo study, sheets of Genocel-L or Pelnac were applied to skin defects created on the backs of C57BL/6JJcl mice. On days 7, 14, and 21, the remaining wound area was evaluated and specimens were harvested for Hematoxylin and Eosin, Azan, anti-CD31, CD68, and CD163 staining to assess neoepithelialization, granulation tissue, capillary formation, and macrophage infiltration.

Results

Genocel-L had a lower water content than the conventional Genocel and a slower degradation than Genocel and Pelnac. In the in vivo experiment, no significant differences were observed between Genocel-L and Pelnac in relation to the wound area, neoepithelium length, granulation formation, and the number of newly formed capillaries. The area of newly formed capillaries in the Pelnac group was significantly larger than that in the Genocel-L group on day 21 (p < 0.05). Regarding macrophage infiltration, significantly more M2 macrophages were induced in the Pelnac group on days 14 and 21, and the M2 ratio was larger in the Pelnac group (p < 0.05) during the entire process.

Conclusions

Genocel-L has a lower water content and slower degradation rate than the conventional Genocel. Genocel-L had equivalent efficacy as a skin substitute to Pelnac, and can therefore be considered feasible for use as a skin substitute. However, a manufacturing method that can further modify Genocel-L is required to recover its early angiogenic potential.

The anterior cingulate cortex is critical for acute stress-induced hypersensitivity in mice

Stress can be categorized according to physical, psychological and social factors. Exposure to stress produces stress-induced hypersensitivity and forms negative emotions such as anxiety and depression. For example, acute physical stress induced by the elevated open platform (EOP) causes prolonged mechanical hypersensitivity. The anterior cingulate cortex (ACC) is a cortical region involved in pain and negative emotions. Recently, we showed that mice exposed to the EOP changed spontaneous excitatory, but not inhibitory transmission in layer II/III pyramidal neurons of the ACC. However, it is still unclear whether the ACC is involved in the EOP induced mechanical hypersensitivity, and how the EOP alters evoked synaptic transmission on excitatory and inhibitory synaptic transmission in the ACC. In this study, we injected ibotenic acid into the ACC to examine if it was involved in stress-induced mechanical hypersensitivity induced by EOP exposure. Next, by using whole-cell patch-clamp recording from brain slice preparation, we analyzed action potentials and evoked synaptic transmission from layer II/III pyramidal neurons within the ACC. Lesion of the ACC completely blocked the stress-induced mechanical hypersensitivity induced by EOP exposure. Mechanistically, EOP exposure mainly altered evoked excitatory postsynaptic currents such as input-output and paired pulse ratio. Intriguingly, the mice exposed in the EOP also produced low-frequency stimulation induced short-term depression on excitatory synapses in the ACC. These results suggest that the ACC plays a critical role in the modulation of stress-induced mechanical hypersensitivity, possibly through synaptic plasticity on excitatory transmission.

Lower Lip Reconstruction Using a Sensory Anterolateral Thigh Flap as the First Choice

Local flaps from the upper lip and cheeks have been the first choice for two-thirds to total resection of the lower lip. However, these local flap techniques involve many clinical problems, including small a mouth, drooling, scarring, and hypesthesia. The improvement of free anterolateral thigh (ALT) flap transfer can solve these problems with expansion of the application of free flaps for lower lip reconstruction. The patient in this case was a 56-year-old man with squamous cell carcinoma of the lower lip (cT3N1M0). Subtotal lower lip resection preserving both corners of the mouth with bilateral neck dissection was performed. Simultaneously, a sensory ALT flap was elevated with an 8 × 6 cm skin island and a lateral femoral cutaneous nerve. The lateral and medial sides of the fascia lata were processed into 1-cm-wide strings, which were tunneled through the orbicularis oris muscle of the upper lip and sutured to the orbicularis oris muscle at the mucosal side of the philtrum. The lateral femoral cutaneous nerve and right mental nerve were sutured. At 3 months, a second surgery was performed to replace the ALT flap on the white labial side with a clavicle full-thickness skin graft. This surgery achieved four important factors: opening and closing of the mouth, sensory function of the lower lip, cosmetic appearance, and minimization of donor-site damage. We believe the worldwide improvement of microsurgery techniques enables lower lip reconstruction using the sensory ALT flap to be selected as the first choice for two-thirds to total lower lip defects.

Deep Infantile Hemangioma in the Involuting Phase That Was Difficult to Diagnose before Surgery

Infantile hemangioma (IH) is a common pediatric vascular tumor and is easily diagnosed in most cases based on the clinical course and appearance, but deep IHs are difficult to diagnose based on external appearance alone. Clinical and imaging findings are therefore important clues to the diagnosis of soft tissue tumors; however, a definitive diagnosis is decided based on the pathological examination of biopsy or resection specimens. A 1-year-old girl with a subcutaneous mass on her glabella was referred to our hospital. At 3 months of age, her mother noticed a tumor that swelled when she cried. It gradually enlarged, and ultrasonography and magnetic resonance imaging were performed at 12 months of age. Doppler ultrasonography showed a hypo-vascular mass. Magnetic resonance imaging revealed a subcutaneous mass with low-intensity on T1-weighted image and slightly high-intensity on T2-weighted image, with tiny flow voids. Computed tomography showed no frontal bone defect. The soft tissue tumor could not be diagnosed based on these imaging findings; thus, we decided to perform total resection under general anesthesia. A histopathological examination showed a highly cellular tumor with capillaries with opened small vascular channels and glucose transporter 1 positivity. Thus, it was diagnosed as deep IH transitioning from the proliferative phase to the involuting phase. Deep IHs are difficult to diagnose because characteristic imaging findings disappear during the involuting phase. We emphasize the importance of performing Doppler ultrasonography in the early phase (eg, at 6 months of age) for soft tissue tumors of infancy.

Evaluating the sampling effort for the metabarcoding‐based detection of fish environmental DNA in the open ocean

Clarifying the effect of the sampling protocol on the detection of environmental DNA (eDNA) is essential for appropriately designing biodiversity research. However, technical issues influencing eDNA detection in the open ocean, which consists of water masses with varying environmental conditions, have not been thoroughly investigated. This study evaluated the sampling effort for the metabarcoding‐based detection of fish eDNA using replicate sampling with filters of different pore sizes (0.22 and 0.45 μm) in the subtropical and subarctic northwestern Pacific Ocean and Arctic Chukchi Sea. The asymptotic analysis predicted that the accumulation curves for detected taxa did not saturate in most cases, indicating that our sampling effort (7 or 8 replicates, corresponding to 10.5–40 L of filtration in total) was insufficient to fully assess the species diversity in the open ocean and that tens of replicates or a substantial filtration volume were required. The Jaccard dissimilarities between filtration replicates were comparable with those between the filter types at any site. In subtropical and subarctic sites, turnover dominated the dissimilarity, suggesting that the filter pore size had a negligible effect. In contrast, nestedness dominated the dissimilarity in the Chukchi Sea, implying that the 0.22 μm filter could collect a broader range of eDNA than the 0.45 μm filter. Therefore, the effect of filter selection on the collection of fish eDNA likely varies depending on the region. These findings highlight the highly stochastic nature of fish eDNA collection in the open ocean and the difficulty of standardizing the sampling protocol across various water masses.

Development of a novel regenerative therapy for malignant bone tumors using an autograft containing tumor inactivated by high hydrostatic pressurization (HHP)

Surgical resection of malignant bone tumors leads to significant defects in the normal surrounding tissues that should be reconstructed to avoid amputation. Our research aimed to inactivate osteosarcoma (OS)-affected bone to obtain autologous bone grafts for bone defect reconstruction using a novel therapy called high hydrostatic pressurization (HHP) therapy. The key points are complete tumor death and preservation of the non-denatured native extracellular matrix (ECM) and bone tissue by HHP. Previously, we found that HHP at 200 MPa for 10 min can completely inactivate cells in normal skin and skin tumors, including malignant melanoma and squamous cell carcinoma while maintaining their original biochemical properties and biological components. Based on our previous research, this study used HHP at 200 MPa for 10 min to eradicate OS. We prepared an OS cell line (LM8), pressurized it at 200 MPa for 10 min, and confirmed its inactivation through morphological observation, WST-8 assay, and live/dead assay. We then injected OS cells with or without HHP into the bone marrow of the murine tibia, after which we implanted tumor tissues with or without HHP into the anterior surface of the tibia. After HHP, OS cells did not proliferate and were assessed using a live/dead assay. The pressurized cells and tumors did not grow after implantation. The pressurized bone was well prepared as tumor-free autologous bone tissues, resulting in the complete eradication of OS. This straightforward and short-pressing treatment was proven to process the tumor-affected bone to make a transplantable and tumor-free autologous bone substitute.

Dried human-cultured epidermis accelerates wound healing in a porcine partial-thickness skin defect model

Introduction

Autologous cultured epidermis (CE) is an effective approach for overcoming the deficiency of donor sites to treat extensive burns. However, the production of autologous CE takes 3-4 weeks, which prevents its use during the life-threatening period of severe burns. In contrast, allogeneic CE can be prepared in advance and used as a wound dressing, releasing several growth factors stimulating the activity of recipient cells at the application site. Dried CE is prepared by drying CEs under controlled temperature and humidity conditions until all the water is completely removed and no viable cells are present. Dried CE accelerates wound healing in a murine skin defect model and is potentially a new therapeutic strategy. However, the dried CE safety and efficacy have not yet been studied in large animal models. Therefore, we studied the safety and efficacy of human-dried CE in wound healing using a miniature swine model.

Methods

Human CE was manufactured using Green's method from donor keratinocytes. Three types of CEs (Fresh, Cryopreserved, and Dried) were prepared, and the ability of each CE to promote keratinocyte proliferation was confirmed in vitro. Extracts of the three CEs were added to keratinocytes seeded in 12-well plates, and cell proliferation was evaluated using the WST-8 assay for 7 days. Next, we prepared a partial-thickness skin defect on the back of a miniature swine and applied three types of human CE to evaluate wound healing promotion. On days 4 and 7, the specimens were harvested for hematoxylin-eosin, AZAN, and anti-CD31 staining to assess epithelialization, granulation tissue, and capillary formation.

Results

The conditioned medium containing dried CE extract significantly enhanced keratinocyte proliferation compared to the control group (P < 0.05). In vivo experiments revealed that human-dried CE significantly accelerated epithelialization at day 7 to the same extent as fresh CE, compared to the control group (P < 0.05). The three CE groups similarly affected granulation formation and neovascularization.

Conclusions

Dried CE accelerated epithelialization in a porcine partial-thickness skin defect model, suggesting that it may be an effective burn treatment alternative. A clinical study with a long-term follow-up is needed to assess the applicability of CEs in clinics.

Establishment of a keratinocyte and fibroblast bank for clinical applications in Japan

Regenerative medicine products using allogeneic cells, such as allogeneic cultured epidermis (allo-CE), have become a more critical therapeutic method for the treatment of burns. However, there are no clinically available allo-CE products in Japan. Therefore, establishing a quality-controlled cell bank is mandatory to create regenerative medical products using allogeneic cells. In this study, we selected ten patients from the Department of Plastic Surgery of Kyoto University Hospital to become cell donors. We performed medical interviews and blood sampling for the donor to ensure virus safety. We examined the tissues and isolated cells by performing a nucleic acid test (NAT). To establish a master cell bank, quality evaluation was performed according to the International Conference of Harmonization (ICH) Q5A. Serological tests of the blood samples from the ten donors showed that two of them were ineligible. The cells registered in the cell bank were found to be compatible after virus testing was performed, and a master cell bank was constructed. Hence, we established a keratinocyte and fibroblast bank of clinically usable human cultured cells in Japan for the first time.

Patient-Reported Outcomes After Autologous Fat Grafting in Prosthetic Breast Reconstruction: Prospective Cohort Study Using a Multivariate Analysis

INTRODUCTION

There is widespread recognition of the importance of assessment of patient satisfaction and well-being after breast reconstruction. However, few studies of fat grafting performed simultaneously with implant-based breast reconstruction (IBBR) have accounted for confounding factors, such as patient background and information bias. The aim of this study was to examine patient satisfaction and well-being using multivariate analysis of BREAST-Q scores in patients treated with IBBR combined with fat grafting.

METHODS

Seventy-one consecutive patients who underwent IBBR with silicone breast implants were enrolled for a prospective cohort study. Among these patients, 56 responded to the BREAST-Q questionnaire, including 24 who underwent fat grafting at the same time as IBBR (FAT+ group) and 32 who underwent IBBR alone (FAT- group). The BREAST-Q questionnaire was completed 1 year after surgery. Statistical analysis was performed using descriptive and summary statistics to identify differences between the 2 groups.

RESULTS

Logistic regression analysis showed that the FAT+ group was significantly more likely than the FAT- group to have satisfaction with breasts (P = 0.0201) and satisfaction with outcome (P = 0.0364).

CONCLUSIONS

Multivariate analysis with consideration of confounding factors indicated that addition of fat grafting to IBBR improves outcomes of breast reconstruction. These results suggest that a minor surgical procedure of fat grafting can improve patient satisfaction and outcomes after breast reconstruction.

Use of the duplication range concept for understanding morphology and predicting prognosis in thumb polydactyly

This study systematically and comprehensively analysed 129 thumb polydactylies in 122 patients using a duplicating range concept based on the level of skin and skeletal bifurcation. Numerical levels were defined along the longitudinal axis of the ulnar thumb duplicate from distal to proximal: level 0 (thumb tip) to level 6 (carpometacarpal joint). The relationships between duplication range and morphological parameters were evaluated. Nail asymmetry was associated with skin bifurcation levels 0 to 2. Proximal phalangeal asymmetry and interphalangeal joint deviation, associated with skin bifurcation levels were assigned scores of 1 to 2.5 and 1 to 2, respectively. Metacarpophalangeal joint deviation had a bimodal distribution, at levels 1.5 and 4 of the longitudinal axes. Morphological similarity was found in patients with the same duplication range. The duplication range concept could potentially improve our understanding of morphology variation and predicting prognoses in thumb polydactyly.Level of evidence: III.

Central Mandibular Reconstruction by Semiopen Wedge Osteotomy Double-barrel Fibula Flap for a Slim Aesthetic Appearance

Mandibular reconstruction involving the central segment after malignant tumor resection requires the achievement of both functional and aesthetic quality. Three-dimensional reproduction based on the concept of a double arc composed of a marginal arc and an occlusal arc is important. Most reports of fibula flaps applied three-segmented closed wedge fibula osteotomy (bilateral and central segments); however, the aesthetic outcome sometimes became too stout for female patients because of the large central segment. We performed four-segmented fibula osteotomy for a 78-year-old woman using a semiopen wedge technique characterized by a half-open wedge and half-closed wedge. This procedure obtained a slim mandibular contour and made double-barrel reconstruction easier to apply. We used titanium plates that were prebent according to the shape of a three-dimensional model constructed from CT data. Small bone cortex fragments made from a surplus fibula segment were inserted in a half-opened area. The build-up preparation for central mandibular reconstruction was all performed at the lower leg area before cutting the peroneal pedicle. This prefabricated double-barrel fibula free flap was transferred to the mandibular defect with arterial and venous anastomosis to the right superior thyroid artery, right external jugular vein, and right common facial vein. Although the patient was nearly 80 years of age, the bone segments, including free cortex tips, were fused with smooth remodeling. Semiopen wedge osteotomy can be a key to reproducing an aesthetically slim feminine chin with a functional height of mandibular bone maintained for stability of the dental prosthesis.

Two-stage skin grafting using a basic fibroblast growth factor-impregnated artificial dermis

For traditional artificial dermises, a waiting period of approximately three weeks is required after the first implantation before they are adequately vascularized. The objective of this retrospective case series was to investigate whether full-thickness skin defects, requiring surgical reconstruction, could be successfully treated by implantation of a basic fibroblast growth factor (bFGF)-impregnated artificial dermis and secondary skin grafting with a shorter waiting period. Between January 2019 and January 2021, 19 skin defects in 14 patients (7 male and 7 female) were treated with two-stage skin grafting using bFGF-impregnated collagen-gelatin sponge (CGS). All of them were included in this case series, and the waiting period for skin grafting, success rate of skin grafting, infection during the waiting period, and scar quality 6–12 months postoperatively were retrospectively investigated. As a result, all skin grafting surgeries were successfully performed with a waiting period of 13.3 ± 4.3 days. Infection during the waiting period was observed in three lesions (15.8%); however, all infections were controllable. Postoperative scar quality was acceptable (Vancouver Scar Scale score range, 1–8). In conclusion, compared to traditional artificial dermises, bFGF-impregnated CGSs have the potential to shorten the waiting period without decreasing the success rate of skin grafting. Further studies are required to confirm this finding.

•

We previously developed a novel artificial dermis which is capable of sustained release of bFGF.

•

Skin defects were successfully treated by two-stage skin grafting using bFGF-impregnated CGS.

•

The use of bFGF-impregnated CGS allowed for a short waiting period for secondary skin grafting.

Group A Streptococcal Rapid Antigen Detection Test: A Clinical Study to Evaluate the Reproducibility Using Human Wound Samples

BACKGROUND

The early diagnosis of necrotizing soft tissue infection (NSTI) caused by group A streptococcus (GAS) for performing debridement surgery is key to the patient survival. In 1996, the diversional use of a GAS-rapid antigen detection test (RADT) for pharyngitis was reported, quickly spreading as a clinically useful method. However, no clinical study has evaluated the reliability of RADT by using wound samples. This is the first study using clinical wound samples to examine the reproducibility between GAS-RADT and wound culture.

METHODS

Patients in whom wound culture samples were clinically necessary were included in this study. Two samples were obtained simultaneously: one for isolation of bacteria as wound culture and the other for GAS-RADT, with written informed consent. The reproducibility between GAS-RADT and wound culture was statistically evaluated by Cohen's kappa coefficient.

RESULTS

One hundred samples from 94 patients were collected from 2020 to 2021. Two samples were GAS-positive on wound culture, and both were RADT-positive (positive reproducibility: 100%). Ninety-eight samples were GAS-negative on wound culture; of these, 97 were RADT-negative (negative reproducibility: 99%). Cohen's kappa coefficient was 0.80, indicating excellent agreement beyond chance. None of the bacteria showed cross-reactional influences. The only discrepant case (RADT-positive and wound culture-negative) was attributed to the administration of antibiotics for 2 days before the sampling.

CONCLUSIONS

The reproducibility between GAS-RADT and wound culture was statistically excellent, underscoring the reliability of GAS-RADT for wounds.

Adjustable biodegradability of low-swelling hydrogels prepared from recombinant peptides based on human collagen type 1

An ideal hydrogel for tissue engineering and regenerative therapy is cytocompatible, biocompatible, and has low-swelling characteristics. Recently, a novel low-swelling hydrogel with a homogenous structure was developed by crosslinking a recombinant peptide, modeled on human collagen type 1 (RCPhC1), with a four-arm polyethylene glycol (tetra-PEG). Here, we hypothesized that the biodegradability of the RCPhC1 hydrogel was adjustable by altering its initial polymer concentration. Three types of RCPhC1 hydrogels were prepared using the initial polymer at different concentrations, and their morphology, swelling ratio, collagenase degradability, cytocompatibility, biocompatibility, and biodegradability were compared. The results revealed a low swelling ratio. The higher the concentration of the initial polymer, the longer it took for it to be degraded by collagenase. The average cell viability ratio was over 92% when using the direct contact method, which suggests that the hydrogels have excellent cytocompatibility. No death, tumorigenesis, exposure of the implants, or skin necrosis associated with the subcutaneous implantation of the hydrogels was found in mice in vivo. Moreover, histological evaluation revealed the formation of a thin fibrous capsule, which suggests an acceptable biocompatibility. Furthermore, as hypothesized, it was confirmed that the biodegradability can be adjusted by changing the initial polymer concentration. Collectively, the ability to fine-tune the biodegradability of RCPhC1 hydrogels demonstrates their potential for use in various clinical applications.

Morphology of Schwann Cell Processes Supports Renal Sympathetic Nerve Terminals With Local Distribution of Adrenoceptors

Nerves in the renal parenchyma comprise sympathetic nerves that act on renal arteries and tubules to decrease blood flow and increase primary urine reabsorption, respectively. Synaptic vesicles release neurotransmitters that activate their effector tissues. However, the mechanisms by which neurotransmitters exert individual responses to renal effector cells remain unknown. Here, we investigated the spatial and molecular compositional associations of renal Schwann cells (SC) supporting the nerve terminals in male rats. The nerve terminals of vascular smooth muscle cells (SMCs) enclosed by renal SC processes were exposed through windows facing the effectors with presynaptic specializations. We found that the adrenergic receptors (ARs) α2A, α2C, and β2 were localized in the SMC and the basal side of the tubules, where the nerve terminals were attached, whereas the other subtypes of ARs were distributed in the glomerular and luminal side, where the norepinephrine released from nerve endings may have indirect access to ARs. In addition, integrins α4 and β1 were coexpressed in the nerve terminals. Thus, renal nerve terminals could contact their effectors via integrins and may have a structure, covered by SC processes, suitable for intensive and directional release of neurotransmitters into the blood, rather than specialized structures in the postsynaptic region.

Group G Streptococcal Necrotizing Soft Tissue Infection: A Pitfall of Rapid Antigen Detection Test for Group A

Background

Necrotizing soft tissue infection (NSTI) caused by group A Streptococcus (GAS) is a life-threatening disease with high morbidity and mortality. Recently, group G Streptococcus (GGS) is increasingly reported as a cause of NSTI, which shows a similar fatality rate. A rapid antigen detection test (RADT) was used for GAS-induced NSTI to assist in the immediate diagnosis when judging the need for debridement surgery.

Methods

We describe 2 NSTI cases in which an RADT for GAS was negative, and in which GGS-induced NSTI was subsequently diagnosed. Both cases involved patients over 80 years of age whose medical histories included multiple conditions, including cardiac disorder and lower leg disease. After making a 1-cm skin incision at the central part of erythema, samples for both a wound culture and an RADT for GAS were taken from the subcutaneous layer.

Results

The RADTs were negative; however, the rapidly progressing clinical courses suggested the need for immediate debridement surgeries under general anesthesia. Removal of the skin and subcutaneous tissue and an incision for drainage achieved limb salvage. Wound cultures identified Group G Streptococcus (Streptococcus dysgalactiae) without other bacteria. Negative pressure wound therapy and split-layer mesh skin graft surgery cured the severe wounds without the need for amputation.

Conclusions

Surgeons must be aware of the limitations of the RADT for GAS and determine the appropriate initial treatment based on comprehensive physical and laboratory findings.

Analgesic effect of gastrin-releasing peptide in the dorsal horn

Itch and pain are both unpleasant, but they are discrete sensations. Both of these sensations are transmitted by C-fibers and processed in laminae I-II of the dorsal horn. To examine whether pruriception modulates pain, we first confirmed the activation of cells in the itch-related circuits that were positive for gastrin-releasing peptide (GRP) and GRP receptor (GRPR) using a paw formalin injection model. This pain model with typical biphasic pain behavior increased c-Fos but did not affect the expressions of GRP and GRPR mRNAs in the dorsal horn. Using c-Fos expression as a marker for activated cells, we confirmed that formalin injection increased the number of cells double-labeled for c-Fos and GRP or GRPR in the dorsal horn. The emergence of these neurons indicates the activation of itch-related circuits by acute pain signals. The effect of an antagonist for a GRPR was examined in the paw formalin injection model. Intrathecal chronic antagonization of spinal GRPR enhanced the onset of phase II of paw formalin injection-induced pain behavior. Exogenous intrathecal GRP infusion to the paw-formalin injection model not only showed significant reduction of pain behavior but also increased c-Fos in the inhibitory neurons in the dorsal horn. The anti-nociceptive effect of spinal GRP infusion was observed in the peripheral inflammation model (complete Freund’s adjuvant injection model). In this study we suggest that painful stimuli activated itch-related neuronal circuits and uncovered the spinal activation of the itch-induced analgesic effect on acute and established inflammatory pain.

Dried human cultured epidermis accelerates wound healing in diabetic mouse skin defect wounds

Cryopreserved allogeneic cultured epidermis (CE) is used for treating second-degree burn wounds and diabetic foot ulcers; however, the need for cryopreservation limits its use. We have previously reported that CE accelerates wound healing irrespective of its viability and hypothesized that dehydrated CEs lacking living cells may act as an effective wound dressing. We prepared dried CE and investigated its morphological and physical properties and wound-healing effects and compared them with those of cryopreserved CE. Hematoxylin-eosin staining, immunostaining for basement membrane, and electron microscopy revealed that the morphologies of dried CE and cryopreserved CE were comparable and that the membrane structure was not damaged. The breaking strength, modulus of elasticity, and water permeability of dried CE were comparable with those of the cryopreserved CE. Furthermore, the levels of various active cytokines and chemokines in dried CE were comparable with those in cryopreserved CE. Dried CE applied to skin defect in diabetic mice significantly reduced the wound area and increased the new epithelium length 4 and 7 days after implantation, similar to that observed for cryopreserved CE. Consequently, dried CE had similar morphological and physical properties and wound-healing effects compared with those of cryopreserved CE and can be a physiological and versatile wound-dressing.

Pyoderma Gangrenosum after Breast Cancer Resection: A Less-invasive and Early Treatment Using the Skin around Ulcers

Surgical invasion is a risk factor of pyoderma gangrenosum (PG). A total of 25% of postoperative PG cases were reported to occur after breast surgeries, including bilateral breast reduction and breast reconstruction following cancer resection. Immunosuppressive therapy and less-invasive wound therapy are necessary; however, the complete healing of ulcers takes 5.1 months on average. We herein report a case of skin grafting under a surgical concept of less-invasive and short-term treatment. An 82-year-old woman complained of a high fever and severe pain at her breast wounds after bilateral breast cancer resection. Although we performed emergency debridement surgery to remove the necrotic tissue, suspecting surgical site infection and inflammation, her high fever persisted. She was diagnosed with PG because of the physical findings of characteristic painful, sterile ulcerations, bullae and pustules, and the pathological abundance of neutrophils in the absence of infection and vasculitis. Oral administration of prednisolone 30 mg/day improved the symptoms, and we applied negative-pressure wound therapy (NPWT) from day 16 following debridement surgery. After the gradual reduction of oral steroid intake to 12.5 mg/day, we performed skin grafting surgery. To limit the surgical invasion, we used the surplus skin around the ulcers. Split-thickness mesh skin grafts were fixed by NPWT to avoid the use of tie-over sutures. We achieved short-term treatment of PG with a less-invasive surgical strategy using skin around the ulcers and NPWT.

Acid increases PGE2 in the duodenal mucosa in rats

Attention has recently been paid to the duodenum as the pathophysiologic center of functional dyspepsia. However, the precise mechanisms of symptom generation remain unknown. We here investigated the effect of acid on duodenal prostaglandin E₂ and localization of prostaglandin E₂ related receptors. Sprague–Dawley rats were used for this study. Hydrochloric acid was administered in the duodenum, then prostaglandin E₂ levels in the duodenum were measured using the ELISA. The expression and localization of prostaglandin receptors (EP1–4) and the mRNAs of prostaglandin synthases were investigated using in situ hybridization histochemistry in duodenal tissue. After acid perfusion, prostaglandin E₂ levels in the duodenum significantly increased. EP3 was expressed mainly at the myenteric plexus in the duodenal mucosa, and EP4 at both the epithelial surface and myenteric plexus. Contrary, EP2 was sparsely distributed in the villi and EP1 were not clearly seen on in situ hybridization histochemistry. Prostaglandin-synthetic enzymes were also distributed in the duodenal mucosa. The prostaglandin E₂ levels in the duodenum increased after acidification. Prostaglandin E₂ receptors and prostaglandin E₂-producing enzymes were both observed in rat duodenum. These observations suggest that duodenal prostaglandin E₂ possibly play a role in the symptom generation of functional dyspepsia.

Intraspecific genetic variability and diurnal activity affect environmental DNA detection in Japanese eel

Environmental DNA (eDNA) analysis with species-specific primer/probe sets is promising as a tool to quantify fish abundance and distribution. Nevertheless, several factors could reduce the accuracy of this method. Here, we aimed to analyze whether intraspecific variability and diel activity rhythm affect eDNA detection in Japanese eels (Anguilla japonica). For this purpose, we performed tank experiments focusing on two points. First, we assessed the effects of base pair sequences with probe region polymorphism on eDNA detection. Next, we evaluated the influences of diel rhythm, activity, and individual differences in eDNA release rate on eDNA concentration. We examined the base pair sequences of the probe regions of 20 individuals and found genetic mismatches in two of them. The eDNA concentration was estimated to be much lower in these variants than it was in the other individuals. We conducted a rearing experiment on four non-variant individuals to explore the influences of diel activity and inter-individual differences in eDNA detection. Nocturnal eel activity was reflected in the eDNA detection but the inter-individual differences remained large. The observed weak positive correlations between eDNA concentration and activity suggest that eDNA emission is highly dependent on basal metabolism. The present study suggests that consideration of polymorphic sites at the probe region and diel activity rhythms should improve the accuracy and precision of abundance estimation through eDNA. Such fine-tuning is applicable not only for eels but also for other fishes to be targeted by eDNA technology.

REDV-modified decellularized microvascular grafts for arterial and venous reconstruction

Recently, a decellularized microvascular graft (inner diameter: 0.6 mm) modified with the integrin α4β1 ligand, REDV, was developed to provide an alternative to autologous-vein grafting in reconstructive microsurgery, showing good early-stage patency under arterial flow in rats. This consecutive study evaluated its potential utility not only as an arterial substitute, but also as a venous substitute, using a rat-tail replantation model. Graft remodeling depending on hemodynamic status was also investigated. ACI rat tail arteries were decellularized via ultra-high-hydrostatic pressure treatment and modified with REDV to induce antithrombogenic interfaces and promote endothelialization after implantation. Grafts were implanted into the tail artery and vein to re-establish blood circulation in amputated Lewis rat tails (n = 12). The primary endpoint was the survival of replants. Secondary endpoints were graft patency, remodeling, and regeneration for 6 months. In all but three cases with technical errors or postoperative self-mutilation, tails survived without any evidence of ischemia or congestion. Six-month Kaplan-Meier patency was 100% for tail-artery implanted grafts and 62% for tail-vein implanted grafts. At 6 months, the neo-tunica media (thickness: 95.0 μm in tail-artery implanted grafts, 9.3 μm in tail-vein implanted grafts) was regenerated inside the neo-intima. In conclusion, the microvascular grafts functioned well both as arterial and venous paths of replanted-rat tails, with different remodeling under arterial and venous conditions.

P–017 The maintenance of testicular architecture and germ cell in adult testis tissue under organ culture condition based on the gas-liquid interface method

Study question

Can the gas-liquid interface organ culture system that achieved in vitro spermatogenesis in mice also support in vitro spermatogenesis in human adult testis?

Summary answer

Although the progression of spermatogenesis was not observed, germ cells were maintained without the degeneration of the architecture in both fresh and cryopreserved testicular tissues.

What is known already

Although the research on in vitro spermatogenesis have been conducted for 100 years, only the organ culture system using gas-liquid interface method achieved in vitro spermatogenesis in mice. It has not been verified whether this culture system can be applied to other mammals including humans and induce spermatogenesis.

Study design, size, duration

Testicular tissue was obtained from the transgender patients receiving sex reassignment surgery. Testicular specimens were either immediately processed for cultivation or cryopreserved, using a vitrification freezing protocol. Organ culture of testicular fragments was performed in three different media for a maximum period of 3 weeks to evaluate the short-term changes in the cultured tissues (viability, proliferation and maintenance of germ and somatic cells).

Participants/materials, setting, methods

Fresh and cryopreserved-thawed testis fragments (1–2 mm3) were cultured using the organ culture system in alpha-MEM with knock-out serum replacement (K group), alpha-MEM with lipid-rich BSA (A group) and DMEM with FBS (D group). Luteinizing hormone, follicle stimulating hormone and testosterone were supplemented. The number of germ cells (using DDX4), proliferative activity of germ cells (using EdU assay) and intratubular cell apoptosis (by TdT-mediated dUTP Nick End Labeling) were evaluated by immunohistochemical staining weekly.

Main results and the role of chance

The architecture of the seminiferous tubules was maintained until the second week of culture in both the fresh and the cryopreserved culture group. The number of DDX4-positive germ cells per seminiferous tubule in groups D, K, and A was 49 ± 24, 55 ± 21, 50 ± 26 cells/tubule in 1 day, 32 ± 13, 42 ± 7, 36 ± 21 cells/tubule in 1week, respectively. The numbers gradually decreased to 26 ± 8, 24 ± 6 and 27 ± 18 cells/tubule, in 2 weeks, respectively, with no difference among the groups. The number of intratubular EdU-positive cells of groups D, K, and A was 0.2 ± 0.2, 2.8 ± 2.1, 1.1 ± 0.8 cells/tubule at 1 day, 0.1 ± 0.2, 0.5 ± 0.6, 0.3 ± 0.6 cells/tubule at 1 week, respectively. The values were 0.01, 0.05, and 0.03 at 2 weeks. Thus, EdU-positive cells drastically decreased from the first week of culture. The number of DDX4-positive germ cells and the intratubular EdU-positive cells in the cryopreserved culture group was not different from that in the fresh culture group.

Limitations, reasons for caution

Current organ culture systems are incomplete, being unable to induce human in vitro spermatogenesis. Further research is needed to improve culture condition with the aim of producing fertile sperm of infertile adult male patients.

Wider implications of the findings: Our organ culture system could maintain testis structure and germ cells. By using the testis tissues of the transgender patients, which are available with their consent, we will promote the investigation of the culture condition necessary for germ cell proliferation and differentiation.

Trial registration number

Grant-in-Aid for Scientific Research on Innovative Areas 18H05546, Grant-in-Aid for Young Scientists (A) 17H05098 and Takeda Science Foundation

The Application of PMA (Propidium Monoazide) to Different Target Sequence Lengths of Zebrafish eDNA: A New Approach Aimed Toward Improving Environmental DNA Ecology and Biological Surveillance

Environmental DNA (eDNA) analysis has enabled more sensitive and efficient biological monitoring than traditional methods. However, since the target species is not directly observed, interpretation of results cannot preclude process Type I errors. Specifically, there may be a spatial or temporal gap between the target eDNA and the eDNA source in the sampled area. Moreover, eDNA surveillance lacks the ability to distinguish whether eDNA originated from a living or non-living source. This kind of Type I error is difficult to control for, in part, because the relationship between the state of eDNA (i.e., intracellular or extracellular) and the degradation rate is still unclear. Here, we applied PMA (Propidium monoazide) to eDNA analysis which enabled us to differentiate “intact cells” from “disrupted cells.” PMA is a dye that has a high affinity for double-stranded DNA and forms a covalent bond with double-stranded DNA and inhibits amplification of the bonded DNA molecules by PCR. Since PMA is impermeable to the cell membrane, DNA protected by an intact cell membrane can be selectively detected. In this study, we investigated the workability of PMA on vertebrate eDNA using zebrafish, Danio rerio. Aquarium water was incubated for 1 week to monitor the eDNA degradation process of both intracellular and extracellular eDNA. We developed ten species-specific quantitative PCR assays for D. rerio with different amplification lengths that enabled independent quantification of total eDNA (sum of intracellular and extracellular eDNA, commonly measured in other studies) and intracellular eDNA (DNA in intact cells) and allow for analyses of sequence length-dependent eDNA degradation in combination with PMA. We confirmed that PMA is effective at differentiating “intact” and “disrupted” fish cells. We found that total eDNA and intracellular eDNA have different degradation processes that are dependent on the length of target sequence. For future conservation efforts using eDNA analyses, it is necessary to increase the reliability of the analysis results. The research presented here provides new analysis tools that expand our understanding of the ecology of eDNA, so that more accurate and reliable conclusions can be determined.

OP0187 INCIDENCE OF MALIGNANCY IN JAPANESE PATIENTS WITH RHEUMATOID ARTHRITIS: DATA FROM THE JAPANESE IORRA PATIENT REGISTRY

Background:

The risk of some types of malignancy is increased in patients (pts) with rheumatoid arthritis (RA), compared with the general population. We have previously reported the incidence of malignancy in Japanese pts with RA.1-4

Objectives:

This analysis further evaluated the incidence of malignancy in Japanese pts with RA using recent data from the large prospective observational study, IORRA.

Methods:

This analysis included all pts with RA aged ≥18 years who were enrolled in IORRA from April 2013 to October 2018, with follow-up through October 2019, and participated in ≥2 surveys. Index was defined as the date of the first entry in the IORRA database, with baseline defined as the 6-month period prior to the index date. Malignancies were identified in pt reports of biannual IORRA surveys and confirmed using medical records. Age- and sex-standardised incidence ratios (SIRs) and 95% confidence intervals (CIs) were calculated.

Results:

In total, 8020 pts were included. At baseline, the majority (85.0%) of pts were female; mean disease duration was 12.8 years, 5.8% and 4.8% of pts had a past history of malignancy or comorbid malignancy at baseline, respectively, and the majority (75.9%) of pts were receiving methotrexate (Table). The SIR (95% CI) was 0.90 (0.80, 1.01). SIRs (95% CI) of site-specific malignancies were: breast cancer, 0.91 (0.69, 1.18); lung cancer, 0.67 (0.44, 0.97); colon cancer, 0.93 (0.62, 1.32); stomach cancer, 0.82 (0.56, 1.14); and lymphoma, 3.74 (2.73, 4.96).

Table 1.

Patient demographics and baseline disease characteristics

Patients with RA (N=8020)Age (years), mean (SD)59.3 (13.8)Female, n (%)6816 (85.0)Duration of RA (years), mean (SD)12.8 (10.3)Never smoked, n (%)5086 (66.2)DAS28, mean (SD)2.8 (1.1)J-HAQ, mean (SD)0.60 (0.72)Malignancy status, n (%)Past history of malignancy467 (5.8)Comorbid malignancy at baseline386 (4.8)Medication use, n (%)MTX6088 (75.9)Tacrolimus787 (9.8)Corticosteroids2641 (32.9)bDMARD use1508 (18.8)TNFi1163 (14.5)Tocilizumab311 (3.9)Abatacept106 (1.3)JAK inhibitors4 (0.05)

bDMARD, biological disease-modifying antirheumatic drug; DAS28, Disease Activity Score in 28 joints; JAK, Janus kinase; J-HAQ, Japanese Health Assessment Questionnaire; MTX, methotrexate; N, the number of patients included in the analysis, the number of patients assessed for each characteristic may be fewer than N; n, the number of patients with each characteristic; SD, standard deviation; TNFi, tumour necrosis factor inhibitor

Conclusion:

Overall risk of malignancy was similar to that in the general Japanese population, although a significantly higher risk of lymphoma was identified.

References:

[1]Sugimoto et al. Rheumatol Int 2017; 37: 1871-1878.

[2]Shimizu et al. Clin Rheumatol 2017; 36: 1237-1245.

[3]Askling et al. Ann Rheum Dis 2016; 75: 1789-1796.

[4]Yamada et al. Rheumatol Int 2011; 31: 1487-1492.

Acknowledgements:

Study sponsored by Pfizer Inc. Medical writing support was provided by Anthony G McCluskey, CMC Connect, and funded by Pfizer Inc.

Disclosure of Interests:

masayoshi harigai Speakers bureau: AbbVie Japan, Ayumi, Boehringer Ingelheim Japan, Bristol-Myers Squibb, Chugai, Eisai, Eli Lilly Japan, GlaxoSmithKline, Kissei, Pfizer Japan Inc, Takeda, Teijin, Consultant of: AbbVie Japan, Boehringer Ingelheim Japan, Bristol-Myers Squibb, Kissei, Teijin, Grant/research support from: AbbVie Japan, Asahi Kasei, Astellas, Ayumi, Bristol-Myers Squibb, Chugai, Daiichi-Sankyo, Eisai, Kissei, Mitsubishi Tanabe, Nippon Kayaku, Sekiui Medical, Shionogi, Taisho, Takeda, Teijin, Naohiro Sugitani: None declared, Ryoko Sakai Speakers bureau: Bristol-Myers Squibb, Eisuke Inoue Speakers bureau: Pfizer Japan Inc, Bristol-Myers Squibb, Michika MOCHIZUKI Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Shigeyuki Toyoizumi Employee of: Pfizer R&D Japan, Noritoshi Yoshii Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Naonobu Sugiyama Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Eiichi Tanaka Speakers bureau: AbbVie Japan, Asahi Kasei, Astellas, Ayumi, Chugai, Eisai, Eli Lilly Japan, GlaxoSmithKline, Kyowa, Janssen, Mochida, Pfizer Japan Inc, Takeda, Teijin, Hisashi Yamanaka Speakers bureau: Astellas, Bristol-Myers-Squibb, Pfizer Inc, Mitsubishi Tanabe, Teijin, YLBio, Consultant of: Corrona, LLC

POS0603 ANALYSIS OF FACTORS ASSOCIATED WITH THE EFFECTIVENESS OF ABATACEPT IN THE ORIGAMI STUDY

Background:

The ORIGAMI study is a multicenter, observational study to evaluate the effectiveness, safety, and patient-reported outcomes of abatacept (ABA) in Japanese patients with csDMARD-resistant, Simplified Disease Activity Index (SDAI)-moderate, biologic-naïve rheumatoid arthritis (RA). ABA has shown better effectiveness/efficacy in RA patients with anti-cyclic citrullinated peptide antibody (ACPA) positive (1) and high ACPA titer (2) compared to ACPA negative and low ACPA titer, respectively. However, more accurate predictors of effectiveness in clinical practice are needed than ACPA status.

Objectives:

This post-hoc analysis is aimed to determine the association between ACPA and ABA effectiveness (disease activity and physical function) or retention rate and to investigate other factors associated with the effectiveness of ABA in patients enrolled in the ORIGAMI study.

Methods:

Of the 279 patients in the effectiveness analysis set of the ORIGAMI study, 270 patients with baseline ACPA measurement were analyzed. The patients were divided into the ACPA-positive group (ACPA +ve, ≥4.5 U/mL at baseline) and the ACPA-negative group (ACPA –ve, <4.5 U/mL). Patients’ characteristics, changes in disease activity and physical function (Japanese Health Assessment Questionnaire; J-HAQ) through 52 weeks, and retention rates of ABA at week 52 were evaluated. Baseline characteristics and use of concomitant drugs were analyzed as independent variables by multiple regression analysis using a standard linear model adjusted by SDAI at week 0 to identify factors associated with SDAI change at week 52. In addition, the interaction effects among ACPA status, RF status, and the factor that was significantly associated with SDAI change in multiple regression analysis on changes in SDAI were explored.

Results:

The numbers of ACPA +ve and –ve patients were 226 and 44, respectively. ACPA values (mean ± SD, U/mL) were 280.3 ± 376.8 and 0.9 ± 0.7, and rheumatoid factor (RF) values were 174.8 ± 302.6 and 20.9 ± 61.7 in the ACPA +ve and –ve groups, respectively. Mean (95% confidence interval) changes in SDAI at week 52 were −11.3 (−12.4 to −10.3) and −8.0 (−10.5 to −5.5), and those in J-HAQ were −0.27 (−0.34 to −0.20) and −0.16 (−0.34 to 0.01) in the ACPA +ve and –ve groups, respectively. In the Kaplan–Meier analysis, the retention rates of ABA at week 52 in the ACPA +ve and –ve groups were 72.1% and 58.7%, (discontinuation for any reason), and 91.6% and 75.7% (discontinuation because of lack of effectiveness), respectively. In a multiple regression analysis, the duration of disease (< 1 year) was associated with the change in SDAI at week 52. With respect to SDAI changes, the estimated difference of ACPA +ve and disease duration (< 1 year), ACPA +ve and disease duration (≥1 year), and ACPA –ve and disease duration (< 1 year), versus ACPA −ve and disease duration (≥ 1 year), were −4.26 (p = 0.022), −0.82 (p = 0.618), and −0.93 (p = 0.716), respectively (Fig. 1). The estimated difference of ACPA +ve and RF +ve, ACPA +ve and RF –ve, and ACPA –ve and RF +ve, versus ACPA –ve and RF –ve, were −2.48 (p = 0.060), −2.77 (p = 0.107), and −5.48 (p = 0.087), respectively.

Conclusion:

A higher retention rate as well as better effectiveness of ABA on disease activity and physical function in ACPA +ve group versus ACPA –ve group were shown in the simple subgroup analysis. ABA effectiveness on the SDAI change was significantly better in patients with disease duration <1 year and ACPA +ve compared to those with ACPA −ve and disease duration ≥ 1 year.

References:

[1]Harrold LR et al. J Rheumatol 2018;45(1):32–39.

[2]Sokolove J et al. Ann Rheum Dis 2016;75(4):709–714.

Disclosure of Interests:

Kenta Misaki Speakers bureau: Eisai Co., Ltd., AbbVie GK, Eli Lilly Japan K.K., Ono Pharmaceutical Co., Ltd., Grant/research support from: Ono Pharmaceutical Co., Ltd., Eiichi Tanaka Speakers bureau: AbbVie GK, Asahi Kasei Pharma Corporation, Astellas Pharma Inc, Ayumi Pharmaceutical Corporation, Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., GlaxoSmithKline K.K., Kyowa Pharma Chemical Co., Ltd., Janssen Pharmaceutical K.K., Mochida Pharmaceutical Co., Ltd., Pfizer, Takeda Pharmaceutical Co., Ltd, and Teijin Pharma Ltd., Eisuke Inoue Speakers bureau: Pfizer Japan, Bristol-Myers Squibb K.K., Katsuki Tsuritani Employee of: Bristol-Myers Squibb K.K., Shigeru Matsumoto Employee of: Ono Pharmaceutical Co., Ltd., Hisashi Yamanaka Consultant of: Bristol-Myers Squibb K.K., masayoshi harigai Speakers bureau: AbbVie GK, Ayumi Pharmaceutical Corporation, Bristol-Myers Squibb K.K., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., Pfizer Japan Inc., and Takeda Pharmaceutical Co., Ltd., Consultant of: AbbVie GK, Bristol-Myers Squibb K.K., Chugai Pharmaceutical Co., Ltd., Eli Lilly Japan K.K., and Gilead Sciences Inc., Grant/research support from: AbbVie GK, and Asahi Kasei Corp., Astellas Pharma Inc., Ayumi Pharmaceutical Corporation, Bristol-Myers Squibb K.K., Chugai Pharmaceutical Co., Ltd. Daiichi-Sankyo, Inc., Eisai Co., Ltd., Mitsubishi Tanabe Pharma Corporation., Nippon Kayaku Co., Ltd., Taisho Pharmaceutical Co., Ltd., and Takeda Pharmaceutical Co., Ltd.

Soft tissue abnormalities in Wassel Type VI radial polydactyly: a detailed anatomical study

Wassel VI radial polydactyly is associated with metacarpal adduction and radial deviation of the metacarpophalangeal joint of the ulnar duplicate. The soft tissue abnormalities responsible for these deformities were characterized using preoperative multi-planar three-dimensional ultrasound and intraoperative observation in four patients. In all patients, the abductor pollicis brevis and superficial head of the flexor pollicis brevis inserted into the radial first metacarpal, whereas the adductor pollicis and deep head of the flexor pollicis brevis inserted into the ulnar thumb. Aberrant location of the flexor pollicis longus and absence of the A1 pulley system was associated with severe radial deviation. An additional superficial thenar muscle along the ulnar metacarpal was associated with minimal metacarpal adduction. Uneven forces on the ulnar duplicate could be associated with these characteristic deformities and joint instability. Knowledge of these abnormalities allows better planning of surgery and further insight into this rare radial polydactyly configuration.Level of evidence: II.

Mycorrhizal communities of two closely related species, Pyrola subaphylla and P. japonica, with contrasting degrees of mycoheterotrophy in a sympatric habitat

Mycoheterotrophic plants typically form associations with a narrow range of mycorrhizal fungi. Consequently, mycorrhizal specialization is often considered to be an important step in mycoheterotrophic evolution. However, it remains unclear whether such specialization is likely to occur in plants of the genus Pyrola, which are generally associated with fungi in multiple ectomycorrhizal families. Here, we investigated the mycorrhizal communities of a nearly fully mycoheterotrophic Pyrola species (Pyrola subaphylla), a closely related partially mycoheterotrophic Pyrola species (Pyrola japonica), and a co-occurring autotrophic ectomycorrhizal tree, Quercus crispula, which is their potential carbon source, in a cool-temperate Japanese forest. High-throughput DNA sequencing revealed that numerous common ectomycorrhizal OTUs interact with the two Pyrola species and Q. crispula, thereby providing an opportunity to exploit a certain amount of carbon from common mycorrhizal networks. In addition, not only P. japonica but also P. subaphylla exhibited exceptionally high alpha mycobiont diversity, with 52 ectomycorrhizal OTUs belonging to 12 families being identified as P. subaphylla mycobionts and 69 ectomycorrhizal OTUs in 18 families being detected as P. japonica mycobionts. Nonetheless, the beta mycobiont diversity of P. subaphylla and P. japonica individuals was significantly lower than that of Q. crispula. Moreover, the beta mycobiont diversity of P. subaphylla was found to be significantly lower than that of P. japonica. Therefore, despite their seemingly broad mycorrhizal interactions, the two Pyrola species (particularly P. subaphylla) showed consistent fungal associations, suggesting that mycorrhizal specialization may have developed during the course of mycoheterotrophic evolution within the genus Pyrola.