Dermal toxicity of hexachlorocyclohexane (HCH) in rabbit

Application of HCH (25 mg/kg) on dorsal, ventral and thigh regions of the skin of male rabbits resulted in poisoning and mortality of animals. Morphological changes in skin, liver, kidney, testes and cerebellum together with highly significant alterations in serum and liver enzymatic activity and residue in blood suggested that absorption of HCH and its toxicity could be severe when the pesticide comes in contact with the skin of thigh region of body.     

Dermal melanocytosis in Japanese monkeys (Macaca fuscata)

The skin of Japanese monkeys (Macaca fuscata) shows diffuse discolorations resembling human dermal melanocytosis. Very few laboratory animals have melanocytes in the dermis. The purpose of this study was to clarify the dermatologic characteristics of Japanese monkeys in terms of gross appearance, skin color, and histopathologic findings. A colorimeter was used to record the skin colors of pigmented and nonpigmented sites. Tissue specimens obtained from both types of sites were examined histopathologically. All animals examined had pigmented sites on their bodies, and the discolorations extended over 25% to 33% of the body surface. The colorimeter could detect differences in skin color due to dermal melanocytosis. All parameters of the colorimetric systems used (Yxy, L*a*b*, and L*C*h* systems) demonstrated significant differences between pigmented and nonpigmented sites. In pigmented sites, the epidermis lacked melanocytes, but the dermis had numerous melanocytes with abundant melanin. Activated melanocytes with well-developed dendrites were distributed throughout the upper part of the dermal layer. Melanocytes were not arranged in clusters, and elastic and collagen fibers in the dermis showed no histological abnormalities. Nonpigmented sites lacked melanin granules in both the epidermis and dermis. This study revealed that gross dermal melanocytosis correlated well with colorimetric results and histopathologic findings. These findings suggest that the pigmentation of Japanese monkeys is equivalent to dermal melanocytosis in humans, to the end that Japanese monkeys may be a useful animal model for investigating dermal melanogenesis.     

Factitious (self-inflicted) skin wounds.

We represent 4 of our recent cases of factitious skin wounds. The general aspects of these wounds--including etiology, diagnosis, detection, and treatment--are discussed.     

Asymmetric incision for open rhinoplasty in cleft lip nasal deformity.

One of the problems in the correction of the unilateral cleft lip nasal deformity is the alar web deformity on the mediosuperior side of the nostril. A number of methods for the correction of the alar web deformity have been introduced, but no single procedure has been identified as the standard. In this report, the incision line of the open rhinoplasty was modified and the alar web deformity was corrected by using an incision and closure. Open rhinoplasty with the asymmetric incision was performed on 18 patients with unilateral cleft lip nasal deformity. The incision line used in the normal side was the usual intranasal rim incision line and that used for the columella was the transcolumella incision line. For the cleft side, an intranasal rim incision line was plotted after the rim was lifted upward with forceps to achieve symmetry of the nasal tip. After removal of the forceps, the incision line of the cleft side was displaced outside the nostril. After such an incision, the alar cartilage mobilization and suspension were performed with or without the conchal cartilage graft. All patients used nasal retainers for 6 months after the procedures. So far, satisfactory results have been obtained with the modification of the incision line for open rhinoplasty. This method is unique in designing the incision line, and its procedure is rather simple. The postoperative follow-up period has been 12 to 26 months. A long-term follow-up is still needed, especially in growing children.     

The subsets of keratinocytes responsible for covering open wounds in neonatal rat skin

Full-thickness excisional wounds were made on the dorsal skin of 1-day-old rats to elucidate from where the cells move into the defect and what kinds of cells they are. Immunohistochemical analyses of the wound sites revealed that the following two subsets of keratinocytes were the major contributors to reepithelialization: first, the cells at the forefront of the migrating epithelium, termed leading edge cells, which expressed K14 keratin, known as basal cell-specific keratin, but not K6 or K10 keratins, so that they had probably moved from the basal cell layer; and, second, the cells tentatively termed immature spinous cells, which expressed K14 and K6 but not K10, and formed an ingrowth region following the leading edge cells. These two kinds of cells moved to the open wound area, as a multilayered cell sheet. Fluorescent phalloidin staining experiments indicated that actin filaments became concentrated in the leading edge cells within 6 h postwounding (PW), whereas weak signals of actin filaments were detected in the immature spinous cells. Taken together, the present findings support the view that wound covering in neonatal rat skin is accomplished by a movement en masse of keratinocytes from the bottom half of the surrounding epidermis.     

Development of new reconstructive techniques: use of Integra in combination with fibrin glue and negative-pressure therapy for reconstruction of acute and chronic wounds

Large wounds resulting from severe injuries are generally treated with extended reconstructive operations (e.g., free flaps), which are accompanied by long hospitalizations and risks of infection, thrombosis, and flap loss. Integra is a collagen template that can be used for reconstruction of defects. The take rate and the rate of infection are essential for the successful use of Integra (Johnson and Johnson, Hamburg, Germany). Whether the take rate and integration of Integra could be improved with the use of fibrin glue and negative-pressure therapy was assessed. Between January of 2002 and December of 2002, patients with large defects who underwent Integra grafting for reconstruction were randomly divided into groups receiving either a new treatment with fibrin glue-anchored Integra and postoperative negative-pressure therapy or conventional treatment. Demographic features, cause of the wound, location of the wound, take rate, complications of Integra coverage, time from Integra coverage to skin transplantation, and functional and aesthetic results were assessed. Twelve patients (with similar group distributions with respect to sex, age, and location and cause of the injury) were included in the study. The take rate was 78 +/- 8 percent in the conventional treatment group and 98 +/- 2 percent in the fibrin/negative-pressure therapy group (p < 0.003). The mean period from Integra coverage to skin transplantation was 24 +/- 3 days in the conventional treatment group but only 10 +/- 1 days in the fibrin/negative-pressure therapy group (p < 0.002). The decrease in the interval between coverage with Integra and skin transplantation resulted in shorter hospital stays. The use of fibrin glue and negative-pressure therapy in combination with Integra could shorten the period from coverage to integration, which would be beneficial in terms of decreased risks of infection, thrombosis, and catabolism. Therefore, it is suggested that Integra be used in combination with fibrin glue and negative-pressure therapy to improve clinical outcomes and shorten hospital stays, with decreased risks of accompanying complications.     

Proteomic Analysis of Human Dermal Fibroblast Conditioned Medium (DFCM)

Growth factors and extracellular matrix (ECM) proteins are involved in wound healing. Human dermal fibroblasts secrete wound-healing mediators in culture medium known as dermal fibroblast conditioned medium (DFCM). However, the composition and concentration of the secreted proteins differ with culture conditions and environmental factors. We cultured human skin fibroblasts in vitro using serum-free keratinocyte-specific media (EpiLife? Medium [KM1] and defined keratinocyte serum-free medium [KM2]) and serum-free fibroblast-specific medium (FM) to obtain DFCM-KM1, DFCM-KM2 and DFCM-FM, respectively. We identified and compared their proteomic profiles using bicinchoninic acid assay (BCA), 1-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (1D SDS-PAGE), enzyme-linked immunosorbent assay (ELISA), matrix-assisted laser desorption ionisation-time-of-flight mass spectrometry (MALDI-TOF/TOF MS/MS) and liquid chromatography MS (LC-MS/MS). DFCM-KM1 and DFCM-KM2 had higher protein concentrations than DFCM-FM but not statistically significant. MALDI-TOF/TOF MS identified the presence of fibronectin, serotransferrin, serpin and serum albumin. LC-MS/MS and bioinformatics analysis identified 59, 46 and 58 secreted proteins in DFCM-KM1, DFCM-KM2 and DFCM-FM, respectively. The most significant biological processes identified in gene ontology were cellular process, metabolic process, growth and biological regulation. STRING® analysis showed that most secretory proteins in the DFCMs were associated with biological processes (e.g. wound healing and ECM organisation), molecular function (e.g. ECM binding) and cellular component (e.g. extracellular space). ELISA confirmed the presence of fibronectin and collagen in the DFCMs. In conclusion, DFCM secretory proteins are involved in cell adhesion, attachment, proliferation and migration, which were demonstrated to have potential wound-healing effects by in vitro and in vivo studies.     

Silicone foam sponge for pilonidal sinus: a new technique for dressing open granulating wounds.

A silicone foam sponge has been used to replace the daily packing of deep granulating wounds with moist sterile gauze. In the treatment of pilonidal sinus use of the sponge demands less nursing time and is more comfortable for the patient than the excision and open granulation technique. Patients can usually return to work soon after operation. The method has many applications in surgery, and widespread application of the technique to the management of granulating wounds could result in considerable savings to the NHS in money and skilled nursing time.     

The role of trehalose as a substitute for nitrogen-containing compatible solutes (Ectothiorhodospira halochloris)

The halophilic phototrophic bacterium Ectothiorhodospira halochloris is able to synthesize both nitrogen-containing (betaine, ectoine) and nitrogen-free (trehalose) compatible solutes. In the absence of external ammonium and under nitrogen-limited growth conditions ectoine was metabolized and trehalose partly replaced betaine. The cytoplasmic trehalose concentration did not exceeded 0.5 mol/kg water (approx. 30% of total compatible solutes). A decreasing content of betaine in cells growing under nitrogen limitation is a result of decreased biosynthesis. Apparently, the betaine pool cannot be used as a nitrogen source, not even in a situation of total nitrogen depletion.     

Assessment of the Dermal Bioavailability of Soil-Aged Benzo(a)pyrene

Exposure to polycyclic aromatic hydrocarbons (PAHs) in soil is a major health concern because of their mutagenic and carcinogenic properties. The aim of this research was to determine the dermal bioavailability of benzo(a)pyrene (BaP) aged in either a sandy or a clay soil in order to assess the health risks and remediation goals for the chemical. In vitro flow-through diffusion cell studies were conducted utilizing dermatomed male pig skin. The amount of radioactive chemical was measured that penetrated skin into receptor fluid and which was bound to skin following soap and water decontamination. BaP bioavailability was decreased by 95 to 98% after 3 months of aging in soil relative to the pure compound. Less than 0.3% of the dose was detected in receptor fluid for all treatments. While most of the dose was bound to skin after administering the pure compound, the majority of the radioactivity was found in the soil and decontaminate after aging. The results indicate that the health risk from exposure to BaP is significantly reduced as the compound ages in soil and that less soil cleanup would be needed at sites contaminated with aged BaP.     

繁育川硬皮肿腿蜂替代寄主的筛选

在室内用直接接蜂和药物麻醉寄主后接蜂的方法,对杉棕天牛Callidium villosulumFairmaire、粗鞘双条杉天牛Semanotus sinoauster Gressitt、苹眼天牛Bacchisa dioica (Fairmaire)、星天牛Anoplophora chinensis (Forster)、玉米螟Ostrinia furnacalis (Guenée)、大螟Sesamia inferens (Walker)、桃蛀螟Dichocrocispunctiferalis Guenée、鞭角华扁叶蜂Chinolyda flagellicornis（Smith）、家蝇Musca domestica vicina Macquart和黄粉甲Tenebrio molitor L. 等10种昆虫作为川硬皮肿腿蜂Scleroderma sichuanensis Xiao繁蜂替代寄主的适合性进行了系统的测试,比较了川硬皮肿腿蜂在不同供试寄主上的寄生率、出蜂率、发育历期、后代的雌性比率、寄生繁殖能力和冷藏对成蜂存活的影响。结果表明,不同寄主及寄主的不同处理间只有寄生率和出蜂率两项指标可能有显著差异,能反映繁蜂寄主的适合性。据此,从10种供试寄主中筛选出黄粉甲和玉米螟两种优良的繁蜂替代寄主,为该蜂的大规模繁殖及应用奠定了基础。     

Comparison of physicochemical properties of pollen substitute diet for honey bee (Apis mellifera)

Apis mellifera L., a globally important pollinator, is crucial in the maintenance of its colonies due to a variety of stresses. Healthy nutrition is believed to help grow their population and relieve the stressors. We used our-prepared and commercial diets, and the nutrition contents were then analyzed for free sugar, organic acids, free amino acids, inorganic ions, total polyphenols, vitamin C, and the pH. The total free sugar, organic contents, free amino acids, inorganic ions, and total polyphenols were in the range of 228.59 to 661.00, 0.91 to 20.60, 6.52 to 24.36, 10.25 to 27.61, and 1.65 to 10.17 mg/g, respectively. The highest contents of free sugar, organic acids, free amino acids, inorganic ions, and total polyphenols were found in YBNH (661 mg/g), Megabee (20.60 mg/g), Beebread (24.36 mg/g), AIGT + Soytide (27.61 mg/g), and Beebread (10.17 mg/g), respectively. The pH values were maintained at 4.45 to 5.70 among all ten samples. Group I showed the same level of total free sugars (Group II and Group IV), organic acids (Group II), inorganic ions (Group II, Group III, and Group IV), polyphenols (Group II), and pH (Group IV). For the total free amino acids, Group I showed a significantly higher (P < 0.05) level than that of Group II and Group III. Group I had a comparable nutrition content to the commercial bee diet but had a higher total free amino acid content. High levels of inorganic ions, free amino acids, and organic acids were found in the AIGT + Soytide.     

A Novel Role of Peripheral Corticotropin-Releasing Hormone (CRH) on Dermal Fibroblasts

Corticotropin-releasing hormone, or factor, (CRH or CRF) exerts important biological effects in multiple peripheral tissues via paracrine/autocrine actions. The aim of our study was to assess the effects of endogenous CRH in the biology of mouse and human skin fibroblasts, the primary cell type involved in wound healing. We show expression of CRH and its receptors in primary fibroblasts, and we demonstrate the functionality of fibroblast CRH receptors by induction of cAMP. Fibroblasts genetically deficient in Crh (Crh−/−) had higher proliferation and migration rates and compromised production of IL-6 and TGF-β1 compared to the wildtype (Crh+/+) cells. Human primary cultures of foreskin fibroblasts exposed to the CRF₁ antagonist antalarmin recapitulated the findings in the Crh−/− cells, exhibiting altered proliferative and migratory behavior and suppressed production of IL-6. In conclusion, our findings show an important role of fibroblast-expressed CRH in the proliferation, migration, and cytokine production of these cells, processes associated with the skin response to injury. Our data suggest that the immunomodulatory effects of CRH may include an important, albeit not explored yet, role in epidermal tissue remodeling and regeneration and maintenance of tissue homeostasis.     

Relationship between mechanical properties and collagen structure of closed and open wounds

Mechanical properties and collagen structure of excisional wounds left open are compared with wounds closed by clips. In both wound models, collagen fiber diameter increases with time post-wounding and is related to tensile strength. Clipped wounds show a higher ultimate tensile strength and tangent modulus compared with open wounds. In clipped wounds, newly deposited collagen appears as a biaxially oriented network as observed in normal skin. In open wounds a delay in the organization of the collagen network is observed and parallel wavy-shaped ribbons of collagen fibers are deposited. At long term, the high extensibility observed in open wounds may be due to the sliding of ribbons of collagen fibers past each other.