Comprehensive Analysis of CdS Ultrathin Films Modified by the Substrate Position inside the Reactor Container Using the CBD Technique.

The cadmium sulfide (CdS) n-type semiconductor is one of the most used as a window layer in thin-film solar cells, such as CdTe, CIS, CIGS, and CZTS. Optoelectronic properties are the most important characteristics for window materials. CdS thin films obtained using the chemical bath deposition technique (CBD) have been reported; however, large amounts of precursor solutions are used, which generate considerable amounts of toxic waste. The aim of this work is to reduce the amount of precursor solutions used for CdS growth; for this, it is necessary to consider an efficient position for the substrate inside the reactor container and at the same time allow obtaining CdS thin films with adequate physical properties to be applied in the photovoltaic solar cell development. CdS thin films were deposited on soda-lime/SnO2:F substrates (FTO) using the CBD technique; the substrates were placed in three different arrangements [rack system, step system (up), and step system (down)]. CdS samples with areas of 4 cm2 and a thickness of 27-48 nm were obtained; the X-ray diffraction patterns show CdS thin films with different polycrystalline structures. The morphological measurements reveal different surface formations depending on the substrate position, and resistivity values of around 105 Ω*cm were measured. UV-vis spectra show transmittance values of around 45-94% in the visible region with band gap energy values of around 2.1-2.36 eV. The best physical properties of CdS thin films and an efficient CBD process were obtained when the FTO substrates were located near the bottom of the reactor container with the FTO side down, leading to an optimal configuration that allows reducing the amount of precursor solutions and in this way reduces the toxic waste generated. These results are important in the photovoltaic technology process and environmental impact.

Applications of solar and wind renewable energy in agriculture: A review.

The growing demand for food and the unstable price of fossil fuels has led to the search for environmentally friendly sources of energy. Energy is one of the largest overhead costs in the production of greenhouse crops for favorable climate control. The use of wind-solar renewable energy system for the control of greenhouse environments reduces fuel consumption and so enhances the sustainability of greenhouse production. This review describes the impact of solar-wind renewable energy systems in agricultural greenhouses.

Comparison of the histopathological characteristics of large colorectal laterally spreading tumors according to growth pattern.

OBJECTIVES: Colorectal laterally spreading tumors (LSTs) are widely recognized owing to their structural characteristics. This study aims to clarify the histopathological characteristics of large colorectal LSTs according to growth pattern. METHODS: We studied 297 colorectal LSTs measuring ≥20 mm in diameter. The LSTs were classified into four types: granular homogenous type (LST-G-H), granular nodular mixed type (LST-G-M), non-granular flat elevated type (LST-NG-F), and non-granular pseudo-depressed type (LST-NG-PD). Retrospectively collected data were examined to compare the histopathological characteristics of LSTs according to the growth pattern. RESULTS: LST-G-M lesions (142 lesions) were most common, followed by LST-NG-F (74 lesions), LST-G-H (61 lesions), and LST-NG-PD (20 lesions). The mean tumor diameter of LST-G lesions (38.5 ± 17.2 mm) was significantly greater than that of LST-NG lesions (26.3 ± 7.0 mm, P < 0.001). In particular, 45% of LST-G-M lesions were ≥40 mm in diameter. Adenomas accounted for 54% of LST-G-H lesions compared with only 10% of LST-NG-PD lesions. Pathological T1 carcinomas accounted for 55% of LST-NG-PD lesions and were not found among LST-G-H lesions. CONCLUSIONS: The biological malignancy of colorectal LSTs differs considerably depending on the growth pattern even among large lesions and therefore should be considered when selecting treatment regimens.

Enhancement of water-window soft x-ray emission from laser-produced Au plasma under low-pressure nitrogen atmosphere.

To generate bright water-window (WW) soft x rays (2.3-4.4 nm), gold slab targets were irradiated with laser pulses (1064 nm, 7 ns, 1 J). Emission spectroscopy showed that the introduction of low-pressure nitrogen enhanced the soft x-ray yield emitted from the laser-produced Au plasma. The intensity of the WW x-ray transported in a 400-Pa N2 atmosphere from the laser-produced plasma increased by 3.8 times over that in vacuum. Considering a strong x-ray absorption, the x-ray yield emitted directly from the Au plasma in the N2 gas was evaluated to be 13 times higher than that in vacuum. Although similar measurements were made for various gases, only N2 gas causes an increase in a soft x-ray yield. The processes leading to this enhancement mechanism were revealed by using hydrodynamic simulation and atomic structure codes.

Growth and Self-Assembly of Silicon⁻Silicon Carbide Nanoparticles into Hybrid Worm-Like Nanostructures at the Silicon Wafer Surface.

This work describes the growth of silicon⁻silicon carbide nanoparticles (Si⁻SiC) and their self-assembly into worm-like 1D hybrid nanostructures at the interface of graphene oxide/silicon wafer (GO/Si) under Ar atmosphere at 1000 °C. Depending on GO film thickness, spread silicon nanoparticles apparently develop on GO layers, or GO-embedded Si⁻SiC nanoparticles self-assembled into some-micrometers-long worm-like nanowires. It was found that the nanoarrays show that carbon⁻silicon-based nanowires (CSNW) are standing on the Si wafer. It was assumed that Si nanoparticles originated from melted Si at the Si wafer surface and GO-induced nucleation. Additionally, a mechanism for the formation of CSNW is proposed.

Effect of resveratrol on c-fos expression of rat trigeminal spinal nucleus caudalis and C1 dorsal horn neurons following mustard oil-induced acute inflammation.

The dietary constituent, resveratrol, was recently identified as a transient receptor potential ankyrin 1 (TRPA1) antagonist, voltage-dependent sodium ion (Na+ ) channel, and cyclooxygenase-2 (COX-2) inhibitor. The aim of the present study was to investigate whether pretreatment with resveratrol attenuates acute inflammation-induced sensitization of nociceptive processing in rat spinal trigeminal nucleus caudalis (SpVc) and upper cervical (C1) dorsal horn neurons, via c-fos immunoreactivity. Mustard oil (MO), a TRPA1 channel agonist, was injected into the whisker pads of rats to induce inflammation. Pretreatment with resveratrol significantly decreased the mean thickness of inflammation-induced edema in whisker pads compared with those of untreated, inflamed rats. Ipsilateral of both the superficial and deep laminae of SpVc and C1 dorsal horn, there were significantly more c-fos-immunoreactive SpVc/C1 neurons in inflamed rats compared with naïve rats, and resveratrol pretreatment significantly decreased that number relative to untreated, inflamed rats. These results suggest that systemic administration of resveratrol attenuates acute inflammation-induced augmented nociceptive processing of trigeminal SpVc and C1 neurons. These findings support resveratrol as a potential therapeutic agent for use in alternative, complementary medicine to attenuate, or even prevent, acute trigeminal inflammatory pain.

Surface chemistry and density distribution influence on visible luminescence of silicon quantum dots: an experimental and theoretical approach.

The impact of the surface reconstruction of the density distribution and photoluminescence of silicon quantum dots (QDs) embedded in a silicon oxide matrix (SiOx) has been studied. Annealing treatments carried out on the as-deposited samples provoked the effusion of hydrogen species. Moreover, depending on the surrounding density and coalescence of QDs, they resulted in a change in the average size of the particles depending on the initial local environment. The shift in the luminescence spectra all over the visible region (blue, green and red) shows a strong dependence on the resultant change in the size and/or the passivation environment of QDs. Density functional theoretical (DFT) calculations support this fact and explain the possible electronic transitions (HOMO-LUMO gap) involved. Passivation in the presence of oxygen species lowers the band gap of Si29 and Si35 nanoclusters up to 1.7 eV, whereas, surface passivation in the environment of hydrogen species increases the band gap up to 4.4 eV. These results show a good agreement with the quantum confinement model described in this work and explain the shift in the luminescence all over the visible region. The results reported here offer vital insight into the mechanism of emission from silicon quantum dots which has been one of the most debated topics in the last two decades. QDs with multiple size distribution in different local environments (band gap) observed in this work could be used for the fabrication of light emission diodes (LEDs) or shift-conversion thin films in third generation efficient tandem solar cells for the maximum absorption of the solar spectrum in different wavelength regions.

Development of highly faceted reduced graphene oxide-coated copper oxide and copper nanoparticles on a copper foil surface.

This work describes the formation of reduced graphene oxide-coated copper oxide and copper nanoparticles (rGO-Cu2ONPs, rGO-CuNPs) on the surface of a copper foil supporting graphene oxide (GO) at annealing temperatures of 200-1000 °C, under an Ar atmosphere. These hybrid nanostructures were developed from bare copper oxide nanoparticles which grew at an annealing temperature of 80 °C under nitrogen flux. The predominant phase as well as the particle size and shape strongly depend on the process temperature. Characterization with transmission electron microscopy and scanning electron microscopy indicates that Cu or Cu2O nanoparticles take rGO sheets from the rGO network to form core-shell Cu-rGO or Cu2O-rGO nanostructures. It is noted that such ones increase in size from 5 to 800 nm as the annealing temperature increases in the 200-1000 °C range. At 1000 °C, Cu nanoparticles develop a highly faceted morphology, displaying arm-like carbon nanorods that originate from different facets of the copper crystal structure.

Three-dimensional computed tomography of portopulmonary venous anastomoses in patients with esophageal varices before treatment.

AIM: Portopulmonary venous anastomoses (PPVA) are shunts between esophageal varices and pulmonary veins. Because PPVA can cause serious complications at the time of sclerotherapy for esophageal varices, it is essential to confirm the existence of any PPVA before treatment. METHODS: The study group comprised 101 patients in whom hemodynamics were evaluated on three-dimensional computed tomography (3D-CT) before either elective or prophylactic treatment of esophageal varices at Kitasato University East Hospital from October 2007 through August 2013. The presence or absence of PPVA, laboratory test results and 3D-CT findings were retrospectively examined in these patients. RESULTS: Nine patients had PPVA, and 92 patients did not. The underlying diseases in the PPVA group were: hepatitis C liver cirrhosis in three; non-B, non-C liver cirrhosis in three; non-alcoholic steatohepatitis in one; primary biliary cirrhosis in one; and autoimmune hepatitis in one. The distribution of underlying diseases did not differ between the PPVA group and the non-PPVA group. When the study variables were statistically compared between the groups, the incidence of large, coil-shaped esophageal varices (grade F3) differed significantly between the groups (P = 0.001). Multivariate analyses of factors related to PPVA revealed that only the grade F3 type of esophageal varices differed significantly between the groups (P = 0.005; hazard ratio, 5.21; 95% confidence interval, 3.1-16.4). CONCLUSION: In patients with grade F3 esophageal varices, the treatment method should be selected on the basis of an accurate hemodynamic analysis using 3D-CT before therapy.

Case of minimal deviation adenocarcinoma: possible clinical link to lobular endocervical glandular hyperplasia as its origin.

Minimal deviation adenocarcinoma (MDA) is defined as an extremely well differentiated variant of endocervical adenocarcinoma. Several reports have stated that MDA associates with lobular endocervical glandular hyperplasia (LEGH). It is difficult to distinguish LEGH from MDA based on clinical and histologic similarities. There is no definite evidence proving that LEGH is a precursor lesion of MDA. A 45-year-old woman was admitted to our hospital for minute investigation of her neurological disorder. The multiple-cystic lesion at the uterine cervix was identified by magnetic resonance imaging. Based on her normal histological findings and severe underlying conditions, a careful follow-up strategy was adapted. Two years later, atypical glandular cells were observed and the multiple-cystic lesion had increased. Pathological diagnosis of a conization specimen was MDA. Radical hysterectomy was carried out. Pathological examination revealed coexistence of LEGH and MDA. Her clinical course and histological findings suggested the possibility that LEGH might be a precursor lesion of MDA.

Intra-/inter-laboratory validation study on reactive oxygen species assay for chemical photosafety evaluation using two different solar simulators.

A previous multi-center validation study demonstrated high transferability and reliability of reactive oxygen species (ROS) assay for photosafety evaluation. The present validation study was undertaken to verify further the applicability of different solar simulators and assay performance. In 7 participating laboratories, 2 standards and 42 coded chemicals, including 23 phototoxins and 19 non-phototoxic drugs/chemicals, were assessed by the ROS assay using two different solar simulators (Atlas Suntest CPS series, 3 labs; and Seric SXL-2500V2, 4 labs). Irradiation conditions could be optimized using quinine and sulisobenzone as positive and negative standards to offer consistent assay outcomes. In both solar simulators, the intra- and inter-day precisions (coefficient of variation; CV) for quinine were found to be below 10%. The inter-laboratory CV for quinine averaged 15.4% (Atlas Suntest CPS) and 13.2% (Seric SXL-2500V2) for singlet oxygen and 17.0% (Atlas Suntest CPS) and 7.1% (Seric SXL-2500V2) for superoxide, suggesting high inter-laboratory reproducibility even though different solar simulators were employed for the ROS assay. In the ROS assay on 42 coded chemicals, some chemicals (ca. 19-29%) were unevaluable because of limited solubility and spectral interference. Although several false positives appeared with positive predictivity of ca. 76-92% (Atlas Suntest CPS) and ca. 75-84% (Seric SXL-2500V2), there were no false negative predictions in both solar simulators. A multi-center validation study on the ROS assay demonstrated satisfactory transferability, accuracy, precision, and predictivity, as well as the availability of other solar simulators.

Establishment and intra-/inter-laboratory validation of a standard protocol of reactive oxygen species assay for chemical photosafety evaluation.

A reactive oxygen species (ROS) assay was previously developed for photosafety evaluation of pharmaceuticals, and the present multi-center study aimed to establish and validate a standard protocol for ROS assay. In three participating laboratories, two standards and 42 coded chemicals, including 23 phototoxins and 19 nonphototoxic drugs/chemicals, were assessed by the ROS assay according to the standardized protocol. Most phototoxins tended to generate singlet oxygen and/or superoxide under UV-vis exposure, but nonphototoxic chemicals were less photoreactive. In the ROS assay on quinine (200 µm), a typical phototoxic drug, the intra- and inter-day precisions (coefficient of variation; CV) were found to be 1.5-7.4% and 1.7-9.3%, respectively. The inter-laboratory CV for quinine averaged 15.4% for singlet oxygen and 17.0% for superoxide. The ROS assay on 42 coded chemicals (200 µm) provided no false negative predictions upon previously defined criteria as compared with the in vitro/in vivo phototoxicity, although several false positives appeared. Outcomes from the validation study were indicative of satisfactory transferability, intra- and inter-laboratory variability, and predictive capacity of the ROS assay.

Postoperative concurrent chemoradiotherapy for the high-risk uterine cervical cancer.

AIM: To determine whether concurrent chemoradiotherapy (CCRT) can improve the survival rate of high-risk uterine cervical cancer. MATERIAL & METHODS: We analyzed 16 cases of uterine cervical cancer that had undergone radical hysterectomy and pelvic lymphadenectomy from 2003 to 2008. The patients were eligible if they had histologically confirmed positive parametrial involvement, positive pelvic lymph nodes or non-squamous cell carcinoma. They received 50 Gy of external beam radiotherapy (RT) for the pelvis which was combined with chemotherapy. Cisplatin was administered intravenously every 3 weeks at a dose of 70 mg/m(2) during the RT. For renal function complication case, carboplatin was administered weekly. For control purposes, there were 14 cases treated in our hospital from 1995 to 2003 who had received only RT. RESULTS: We did not find any statistically significant difference in the disease-free survival rate between the CCRT group and the RT group. However, the overall survival rate was significantly higher for patients in the CCRT group compared with the RT group in positive lymph node cases and non-squamous cell carcinoma cases. Adverse effects were more frequent in the CCRT group. Over grade 3 toxicities were manifested as leukopenia, diarrhea and anemia. There was no local recurrence in CCRT group patients. CONCLUSION: CCRT seems to be beneficial for improving the survival rate of either positive lymph node or non-squamous cell carcinoma cases in high-risk uterine cervical cancer patients.

Development of a wound dressing composed of hyaluronic acid sponge containing arginine and epidermal growth factor.

Hyaluronic acid (HA) has the ability to promote wound healing. Epidermal growth factor (EGF) is able to promote the proliferation of various cell types, in addition to epidermal cells. A novel wound dressing was designed using high-molecular-weight hyaluronic acid (HMW-HA) and low-molecular-weight hyaluronic acid (LMW-HA). Spongy sheets composed of cross-linked high-molecular-weight hyaluronic acid (c-HMW-HA) were prepared by freeze-drying an aqueous solution of HMW-HA containing a crosslinking agent. Each spongy sheet was immersed into an aqueous solution of LMW-HA containing arginine (Arg) alone or both Arg and epidermal growth factor (EGF), and were then freeze-dried to prepare two types of product. One was a wound dressing composed of c-HMW-HA sponge containing LMW-HA and Arg (c-HMW-HA/LMW-HA + Arg; Group I). The other was a wound dressing composed of c-HMW-HA sponge containing LMW-HA, Arg and EGF (c-HMW-HA/LMW-HA + Arg + EGF; Group II). The efficacy of these products was evaluated in animal tests using rats. In the first experiment, each wound dressing was applied to a full-thickness skin defect with a diameter of 35 mm in the abdominal region of Sprague-Dawley (SD) rats, leaving an intact skin island measuring 15 mm in diameter in the central area of this skin defect. Commercially available polyurethane film dressing was then applied to each wound dressing as a covering material. In the control group, the wound surface was covered with polyurethane film dressing alone. Both wound dressings (Group I and Group II) potently decreased the size of the full-thickness skin defect and increased the size of the intact skin island, when compared with the control group. The wound dressing in Group II showed particularly potent activity in increasing the distance of epithelization from the intact skin island. This suggests that EGF release from the spongy sheet serves to promote epithelization. The wound dressing in Group II enhanced early-stage inflammation after 1 week, as compared with the other two groups. In the second experiment, each wound dressing was applied to a full-thickness skin defect measuring 35 mm in diameter in the abdominal region of SD rats, after removing necrotic skin caused by dermal burns. Polyurethane film dressing was applied to each wound dressing as a covering material. In the control group, the wound surface was covered with polyurethane film dressing alone. Both wound dressings (Group I and Group II) potently decreased the size of the full-thickness skin defect and increased epithelization from the wound margin, as compared with the control group. The wound dressing in Group II was found to enhance early-stage inflammation after 1 week, as compared with the other two groups. The findings in both experiments indicate that the wound dressing composed of HA-based spongy sheets containing Arg and EGF potently promotes wound healing by inducing moderate inflammation. The release of EGF in the early stages of wound healing induces moderate inflammation. This suggests that wound healing is facilitated directly by topical application of EGF, and indirectly by cytokines derived from inflammatory cells stimulated by EGF.

A case of lower-extremity deep burn wounds with periosteal necrosis successfully treated by use of allogenic cultured dermal substitute.

In patients with burns, bone exposure accompanies serious problems which occasionally lead to amputation. We present a case of an 82-year-old woman who sustained 22% of total body surface area flame burns on her bilateral lower extremities with bone exposure. Despite fascial excision and mesh skin graft, muscles, bones, and tendons were widely exposed on her right leg. The wound was infected by methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. To promote wound healing, we applied an allogeneic cultured dermal substitute (CDS) to the wound surface once weekly, resulting in healthy granulation except for the exposed bone area of the right anterior tibia. We then shaved the cortex of the exposed bone surface until bone marrow bleeding, and grafted mesh skin in combination with CDS. Finally, all wounds healed without osteomyelitis. The use of CDS to treat deep burns exposing bone surface may expand reconstructive options for extremities that otherwise might have been amputated.

Design of a matrix for cultured dermal substitute suitable for simultaneous transplantation with auto-skin graft: evaluation in animal test.

This study focused on the design of a matrix for a cultured dermal substitute (CDS). Two types of cross-linked spongy matrix were designed. The weight ratio of hyaluronic acid (HA) to a cross-linking agent was adjusted to 5:1 (c-5) or 15:1 (c-15). Each HA spongy matrix was combined with collagen (Col) gel, forming 4 groups: Group I, c-5 sponge and Col gel; Group II, c-5 sponge and Col gel with human fibroblasts; Group III, c-15 sponge and Col gel; and Group IV, c-15 sponge and Col gel with human fibroblasts. The physical properties of the matrix depend on the cross-linking conditions. In animal tests using T-cell-deficient F344 rats, materials from Groups I-IV were transplanted onto a full-thickness skin defect, followed by auto-skin grafting. Commercially available artificial dermis composed of collagen sponge was employed as a control. Grafted skin survival in all groups was evaluated according to macroscopic and histological appearances 2 weeks after transplantation. The take rate of auto-skin was higher in Groups I-IV than in control. The take rate of auto-skin was also higher for Groups II and IV than for Groups I and III. This finding indicates that CDS containing human fibroblasts is able to provide more suitable conditions for rat's auto-skin engraftment. The take rate of auto-skin in Group IV was >84%, showing the best results. This finding suggests that CDS comprising highly biodegradable matrix is acceptable for the engraftment of auto-skin, creating no physical barrier to interactions between the wound bed and auto-skin.

Effective treatment of intractable skin ulcers using allogeneic cultured dermal substitutes in patients with systemic lupus erythematosus.

Skin ulcers in systemic lupus erythematosus (SLE) patients are non-healing or intractable, because various factors or complications, including vasculitis and immunosuppressants, impair wound healing. In the present study, we applied cultured dermal substitutes (CDSs) to 3 cases of SLE skin ulcers because various systemic or topical therapies were ineffective. CDSs are prepared by culturing human fibroblasts on two-layered spongy matrices of hyaluronic acid and atelo-collagen, and they effectively promote the healing of severe skin defects. After using CDSs in the 3 cases, healthy granulation tissues formed within 6 weeks, and skin grafts were successfully performed. These results indicate that allogeneic CDSs provide new therapeutic alternatives as topical therapies for intractable skin ulcers in SLE.

Development of a wound dressing composed of a hyaluronic acid sponge containing arginine.

Spongy sheets composed of cross-linked high-molecular-weight (HMW) hyaluronic acid (HA) were prepared by freeze-drying an aqueous HMW-HA solution containing cross-linking agent (Group I). The Group I sheet was immersed into an aqueous low-molecular-weight (LMW) HA solution with or without L-arginine (Arg) and was then freeze-dried to prepare several types of spongy sheets (Groups II-V). The amount of Arg was 1.0 g, 0.5 g, 0.2 g and 0 g in Groups III, IV, V and II, respectively. In the first experiment, each spongy sheet was applied to a full-thickness skin defect with a diameter of 35 mm in the abdominal region of SD rats, with intact skin in the central area measuring 15 mm in diameter. Commercially available polyurethane film dressing was applied over each spongy sheet as a covering material. The control group was covered with polyurethane film dressing alone. All spongy sheets promoted epithelization, as well as angiogenesis, as compared with controls. These findings indicate that HA and Arg are essential for wound healing. Re-epithelizaion was particularly active in Groups IV and V. In the second experiment, each spongy sheet was applied to a full-thickness burn injury measuring 35 mm in diameter in the abdominal region of SD rats, after necrotic skin was surgically removed. Groups II-V showed decreased wound size when compared with Group I and controls. The present findings indicate that the release of LMW-HA and Arg from a cross-linked HMW-HA spongy sheet effectively stimulates wound healing.

Expression profiles of PERIOD1, 2, and 3 in peripheral blood mononuclear cells from older subjects.

AIMS: Circadian clocks regulate daily rhythms of behavior and physiology such as the sleep-wake cycle and hormonal secretion. Numerous characteristics of the behavioral and physiological processes change with age. In this study, we evaluated the circadian clockwork in older people by measuring daily profiles of PERIOD (PER) gene expression in peripheral blood mononuclear cells (PBMCs). MAIN METHODS: Blood samples were collected from 6 healthy older subjects (mean age 62 years) at 2-h intervals over a 24-h period under a semi-constant routine condition where masking effects are minimized. PBMCs were isolated from whole blood and temporal mRNA expression profiles of PER1, PER2, and PER3 were determined by RT-PCR. Phases of the PER rhythms, and times of sleep onset and offset were determined using data from those subjects who showed significant 24-h rhythms. The values for the parameters were compared between the older subjects and 8 young control subjects (mean age 21 years). KEY FINDINGS: Prominent daily rhythms of PER1, PER2, and PER3 mRNA levels, advanced sleep-wake timing and advanced phases of PER rhythms were observed in the older subjects compared to the young controls. There was no significant age-related phase difference in PER1 or PER2 rhythm with respect to sleep timing; however, PER3 expression pattern was altered in the older subjects. SIGNIFICANCE: This preliminary study shows that human circadian clockwork in PBMCs remains intact at least until the presenile stage and suggests that the altered PER3 expression pattern may reflect decreased homeostatic sleep drive in older people.

Case report: a case of pyoderma gangrenosum with intractable leg ulcers treated by allogeneic cultured dermal substitutes.

Pyoderma gangrenosum (PG) is an idiopathic, inflammatory, ulcerative disease of undetermined cause. Both topical and systemic treatments of corticosteroids and cyclosporine are commonly used for the ulcers of PG, but these ulcers are often intractable despite treatment. We employed allogeneic cultured dermal substitutes (CDS) in a patient with intractable ulcers due to PG. The CDS was prepared by cultured human fibroblasts on two-layered sponges of extracellular matrix such as hyaluronic acid and atelo-collagen. In the present case, re-epithelization and healthy granulation were induced by the CDS without increasing the dosage of systemic prednisolone. Then the subsequent autologous skin graft was successfully performed. This indicates that CDS is one of the useful tools for the treatment of intractable ulcers in patients with PG.