Factors influencing Frey syndrome after parotidectomy with acellular dermal matrix

BACKGROUND Frey syndrome,also known as ototemporal nerve syndrome or gustatory sweating syndrome,is one of the most common complications of parotid gland surgery.This condition is characterized by abnormal sensations in the facial skin accompanied by episodes of flushing and sweating triggered by cognitive processes,visual stimuli,or eating.AIM To investigate the preventive effect of acellular dermal matrix(ADM)on Frey syndrome after parotid tumor resection and analyzed the effects of Frey syndrome across various surgical methods and other factors involved in parotid tumor resection.METHODS Retrospective data from 82 patients were analyzed to assess the correlation between sex,age,resection sample size,operation time,operation mode,ADM usage,and occurrence of postoperative Frey syndrome.RESULTS Among the 82 patients,the incidence of Frey syndrome was 56.1%.There were no significant differences in sex,age,or operation time between the two groups(P>0.05).However,there was a significant difference between ADM implantation and occurrence of Frey syndrome(P<0.05).ADM application could reduce the variation in the incidence of Frey syndrome across different operation modes.CONCLUSION ADM can effectively prevent Frey syndrome and delay its onset.

Acellular dermal matrices in reconstructive surgery;history,current implications and future perspectives for surgeons

Large-scale defects of body in the reconstructive surgical practice,and the help-lessness of their repair with autologous tissues,have been an important factor in the development of artificial biological products for the temporary,definitive,or staged repair of these defects.A major advance in the field of plastic and other reconstructive surgery in this regard has been the introduction and successful use of acellular dermal matrices(ADMs).In recent years,not only the type of tissue from which ADMs are produced,product range,diversity and areas of use have increased,but their use in reconstructive fields,especially in post oncologic breast surgery,has become highly regarded and this has favored ADMs to be a potential cornerstone in specific and well-defined surgical fields in future.It is essential that reconstructive surgeons become familiar with some of the ADM’s as well as the advantages and limitations to their use.This review not only provides basic science and clinical evidence of the current use of ADMs in wide range of surgical fields but also targets to keep them as an important backdrop in the arma-mentarium of reconstructive surgeons.Brief considerations of possible future directions for ADMs are also conducted in the end.

The Combined Effect of Lumenato and Ceramide in the Protection of Collagen Damage Induced by Neutrophils in Normal Human Dermal Fibroblasts

Introduction: Collagen is the primary structural protein fibroblasts produce in the skin’s extracellular matrix. Infiltration of neutrophils into the epidermis and dermis by exposure to UV causes collagen damage and contributes to photoaging. Methods: To study the combined effect of Lumenato and ceramide in preventing collagen-1 damage induced by phagocytes, we used co-cultures of normal human dermal fibroblasts (fibroblasts) and activated human neutrophils. The present study aimed to determine the protective effect of the combination of Lumenato and ceramide on fibroblast collagen-1 damage induced by neutrophils. Results: Lumenato (in the range of 6.5 - 208 μg/ml) or ceramide (in the range of 0.1 - 50 μM) inhibited the production of superoxides and MPO by TNFα-stimulated neutrophils, as well as the production of NO by LPS-stimulated macrophages in a dose-dependent manner. The combinations of Lumenato and ceramide, in low concentrations, caused synergistic prevention of fibroblasts’ collagen-1 damage induced by TNFα-activated neutrophils, detected by fluorescence immunostaining and WB analysis. MPO activity in the supernatants of the co-cultures was also synergistically inhibited. Adding Lumenato or ceramide singly or in combinations in these low concentrations to the fibroblast cultures did not affect the expression of collagen-1. The combinations of Lumenato or ceramide in these concentrations also caused a synergistic inhibition of NO production by activated macrophages. Conclusions: The results suggest that combining low concentrations of Lumenato and ceramide results in synergistic protection against fibroblasts’ collagen-1 damage induced by neutrophils, thus indicating their possible potential for enhanced skin health.

Clear Cell Pleomorphic Dermal Sarcoma: A Case Report and Literature Review

Introduction: Atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS) are one spectrum of rare cutaneous neoplasms that typically arise in sun-exposed skin of older population. AFX/PDS is essentially diagnosis of exclusion requiring Immunohistochemical work-up to exclude other types of tumors. Case Report: We present a case involving an ulcerated solitary lesion on the scalp of an elderly man. Histological examination revealed that the dermal tumor was composed of large pleomorphic, epithelioid, and spindle cells with clear cytoplasm. These cells were negative for cytokeratins, melanocytes and smooth muscle markers, but positive for CD10. These findings are consistent with a diagnosis of clear cell (CC) PDS. Conclusion: PDS is a low-grade malignancy that can recur locally and metastasize, which is distinguished from AFX by its larger size and the presence of aggressive histopathologic features including deeper invasion into the subcutaneous tissue, tumor necrosis, and lymphovascular and/or perineural involvement. Among several histopathologic variants, the CC variant is extremely rare with only two cases of PDS reported in the literature to date.

Flavonoids in safflower extract reduce cisplatin-induced damage to human follicle dermal papilla cells by inhibiting DNA damage and Rad17/Chk1/Cdc25C signaling

Background:Cisplatin is a chemotherapeutic agent commonly used clinically for the treatment of various human cancers.Patients often reduce the use of cisplatin due to its side effects,which in turn affects its treatment.This study explored the mechanism of action of safflower extract as an adjuvant traditional Chinese medicine for chemotherapy.Methods:Primary human follicle dermal papilla cells(HFDPCs)were used as target cells for cisplatininduced damage to hair cells.Western blotting was used to investigate the molecular targets of cisplatin and safflower extract in causing HFDPCs damage.Cell survival and cell cycle were analyzed by mitochondrial staining reagent WST-1 and propidium iodide.Results:Cisplatin could reduce the viability of HFDPCs without causing cell death.Cisplatin increased the level of phospho-Rad17 in HFDPCs and activated the Chk1/Cdc25C signaling to reduce the expression of Cdc2 protein,thereby arresting the cells in the G2/M phase.The combination of safflower extract and the flavonoids could effectively inhibit the signal transduction of Rad17/Chk1/Cdc25 in cisplatin-treated cells and reduce the cell population in the G2/M phase.Finally,we also confirmed that safflower extract could effectively inhibit the damage to HFDPCs caused by cisplatin,mainly at the level of reducing the DNA damage caused by cisplatin.Conclusions:Safflower extract can be used as an adjuvant Chinese medicine for chemotherapy to reduce the damage caused by chemotherapy to normal hair follicle cells.

Management of Complex Wounds with Dermal Substitute Assisted by a Negative Pressure System

Introduction: The standard treatment for complex wound care is autografting. The advent of dermal substitutes has provided a novel tool for the preparation of the bed to be grafted. However, most types of dermal matrices require the application of a skin graft a second time. Currently, other strategies have been developed to improve the vascularization process, such as negative pressure wound therapy (NPWT), which has been reported to reduce the time required for vascular growth and dermal matrix integration and thus achieve a shorter waiting period for autologous graft application. The present study aims to evaluate the effectiveness and safety of dermal matrix management associated with NPWT in the treatment of complex wounds. Methods: Seven patients with a diagnosis of complex wounds were enrolled in this study between July 1, 2015, and June 31, 2016. After debridement and having an adequate wound bed, patients who met the criteria for the application of combined therapy were treated with dermal substitutes and a negative pressure system. The percentage of graft integration into the wound bed, complications, length of hospital stay, and duration of therapy were analyzed. Results: The mean age was 42.5 ± 16 (39 - 54) years old;three women and four men were included in the study. The approximate size of skin loss was 120.7 ± 75 cm2 (25 - 250 cm2). The combined therapy of dermal matrix plus NPWT was instituted in all cases for a period of 14 days. There were no complications, with 100% graft integration in 6 of 7 cases. Patients were discharged after a mean hospital stay of 5.4 days. Conclusions: This study demonstrates that the utilization of combined dermal matrix plus NPWT therapy can be performed safely and effectively in patients with complex wounds with low complication rates and a short hospital stay.

Leaf epidermal characters of Lonicera japonica and Lonicera confuse and their ecology adaptation

The leaf epidermis of Japanese honeysuckle （Lonicera japonica Thunb.） and Wild Honeysuckle （Lonicera confusa） in the genus of Flos Lonicerae were mainly observed by scanning electron microscopes （SEM） to study the characteristics of stomata, trichomes and dermal cell, etc.. The results showed that stoma exists only on the lower epidermis and its distribution is irregular, and leaf epidermis consist of epidermis cells, stoma complexes and bushy trichomes including glandular hair and non-glandular hair. On the upper epidermis, anticlinal wall caves in sinuous groove to countercheck the transpiration. Evidences from leaf morphological structures serve as another proof on drought-resistant mechanisms. Some strumaes distributing regularly are hypothesized as oxalic calcium on the lower epidermis under laser scanning confocal microscopy （LSCM） with Fluo-3/AM, which can increase their endurance to drought stress. Therefore, the above characteristics of Flos Lonicerae can reduce the loss of water and make Japanese honeysuckle and Wild Honeysuckle adapt to the droughty environment at Karst area in southwest China. However, there is some difference of the two species. From the SEM （Scanning Electron Microscopy） result, it is shown that on the upper epidermis, some glandular hair regularly present along the midrib of Japanese honeysuckle, but Wild Honeysuckle has no glandular hair on the upper epidermis, which can verify the relationships of Flos Lonicerae species and provide the significance for classification of Flos Lonicerae.

<i>In Vitro</i>Analysis of VEGF and HGF Production by Fibroblast in Cultured Dermal Substitute Combined with EGF-Incorporating Top Dressing

This study aimed to investigate the potential of cultured dermal substitute (CDS) to release angiogenic growth factors when laminated with a membrane containing epidermal growth factor (EGF) as a top dressing. Membranes were prepared by air-drying a solution of hyaluronic acid (HA) and collagen (Col) with or without EGF. Membranes were designed to contain EGF at concentrations of 0, 0.1, 0.2 or 0.5 μg/cm2. CDS was prepared by incorporating fibroblasts into a collagen gel combined with a cross-linked HA spongy matrix, followed by culturing for 5 days. CDS was designed to contain fibroblasts at a density of 2 × 105 (Group I) or 4 × 105 cells/cm2> (Group II). CDS was elevated at the interface between air and culture medium, on the top of which each membrane was placed. This culture system was employed as a wound surface model. Metabolic activity of the fibroblasts in the CDS cultured for 7 days on a wound surface model was measured by MTT assay. The amounts of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) after 7 days of cultivation were measured by using ELISA. Membranes containing EGF ranging from 0.1 to 0.5 μg/cm2> facilitated production of both VEGF and HGF, as compared with control membranes without EGF. However, a membrane containing EGF at a concentration of 0.5 μg/cm2> failed to facilitate fibroblast cytokine production in Group I. These results demonstrated that the EGF-incorporating membrane was able to stimulate fibroblasts in the CDS to synthesize an increased amount of VEGF and HGF in a dose-dependent manner.

Epidermal stem cells and skin tissue engineering in hair follicle regeneration

The reconstitution of a fully organized and functional hair follicle from dissociated cells propagated under defined tissue culture conditions is a challenge stillpending in tissue engineering. The loss of hair follicles caused by injuries or pathologies such as alopecia not only affects the patients' psychological well-being, but also endangers certain inherent functions of the skin. It is then of great interest to find different strategies aiming to regenerate or neogenerate the hair follicle under conditions proper of an adult individual. Based upon current knowledge on the epithelial and dermal cells and their interactions during the embryonic hair generation and adult hair cycling, many researchers have tried to obtain mature hair follicles using different strategies and approaches depending on the causes of hair loss. This review summarizes current advances in the different experimental strategies to regenerate or neogenerate hair follicles, with emphasis on those involving neogenesis of hair follicles in adult individuals using isolated cells and tissue engineering. Most of these experiments were performed using rodent cells, particularly from embryonic or newborn origin. However, no successful strategy to generate human hair follicles from adult cells has yet been reported. This review identifies several issues that should be considered to achieve this objective. Perhaps the most important challenge is to provide threedimensional culture conditions mimicking the structure of living tissue. Improving culture conditions that allow the expansion of specific cells while protecting their inductive properties, as well as methods for selecting populations of epithelial stem cells, should give us the necessary tools to overcome the difficulties that constrain human hair follicle neogenesis. An analysis of patent trends shows that the number of patent applications aimed at hair follicle regeneration and neogenesis has been increasing during the last decade. This field is attractive not only to academic researchers but also to the companies that own almost half of the patents in this field.

Randomized controlled trial of minimally invasive surgery using acellular dermal matrix for complex anorectal fistula

AIM: To compare the efficacy and safety of acellular dermal matrix (ADM) bioprosthetic material and endorectal advancement flap (ERAF) in treatment of complex anorectal fistula. METHODS: Ninety consecutive patients with complex anorectal fistulae admitted to Anorectal Surgical Department of First Affi liated Hospital, Xinjiang Medical University from March 2008 to July 2009, were enrolled in this study. Complex anorectal fistula was diagnosed following its clinical, radiographic, or endoscopic diagnostic criteria. Under spinal anesthesia, patients underwent identification and irrigation of the fistula tracts using hydrogen peroxide. ADM was securely sutured at the secondary opening to the primary opening using absorbable suture. Outcomes of ADM and ERAF closure werecompared in terms of success rate, fecal incontinence rate, anorectal deformity rate, postoperative pain time, closure time and life quality score. Success was defined as closure of all external openings, absence of drainage without further intervention, and absence of abscess formation. Follow-up examination was performed 2 d, 2, 4, 6, 12 wk, and 5 mo after surgery, respectively. RESULTS: No patient was lost to follow-up. The overall success rate was 82.22% (37/45) 5.7 mo after surgery. ADM dislodgement occured in 5 patients (11.11%), abscess formation was found in 1 patient, and fistula recurred in 2 patients. Of the 13 patients with recurrent fistula using ERAF, 5 (11.11%) received surgical drainage because of abscess formation. The success rate, postoperative pain time and closure time of ADM were significantly higher than those of ERAF (P < 0.05). However, no difference was observed in fecal incontinence rate and anorectal deformity rate after treatment with ADM and ERAF. CONCLUSION: Closure of fistula tract opening with ADM is an effective procedure for complex anorectal fistula. ADM should be considered a first line treatment for patients with complex anorectal fistula.

A novel porcine acellular dermal matrix scaffold used in periodontal regeneration

Regeneration of periodontal tissue is the most promising method for restoring periodontal structures.To find a suitable bioactive three- dimensional scaffold promoting cell proliferation and differentiation is critical in periodontal tissue engineering.The objective of this study was to evaluate the biocompatibility of a novel porcine acellular dermal matrix as periodontal tissue scaffolds both in vitro and in vivo.The scaffolds in this study were purified porcine acellular dermal matrix(PADM) and hydroxyapatite-treated PADM(HA-PADM). The biodegradation patterns of the scaffolds were evaluated in vitro.The biocompatibility of the scaffolds in vivo was assessed by implanting them into the sacrospinal muscle of 20 New Zealand white rabbits.The hPDL cells were cultured with PADM or HA-PADM scaffolds for 3,7,14,21 and 28 days.Cell viability assay,scanning electron microscopy(SEM),hematoxylin and eosin(H&E) staining, immunohistochemistry and confocal microscopy were used to evaluate the biocompatibility of the scaffolds.In vitro,both PADM and HA-PADM scaffolds displayed appropriate biodegradation pattern,and also,demonstrated favorable tissue compatibility without tissue necrosis,fibrosis and other abnormal response.The absorbance readings of the WST-1 assay were increased with the time course, suggesting the cell proliferation in the scaffolds.The hPDL cells attaching,spreading and morphology on the surface of the scaffold were visualized by SEM,H&E staining,immnuohjstochemistry and confocal microscopy,demonstrated that hPDL cells were able to grow into the HA-PADM scaffolds and the amount of cells were growing up in the course of time.This study proved that HA-PADM scaffold had good biocompatibility in animals in vivo and appropriate biodegrading characteristics in vitro.The hPDL cells were able to proliferate and migrate into the scaffold.These observations may suggest that HA-PADM scaffold is a potential cell carrier for periodontal tissue regeneration.

Reconstruction of the abdominal wall by using a combination of the human acellular dermal matrix implant and an interpositional omentum flap after extensive tumor resection in patients with abdominal wall neoplasm: A preliminary result

AIM： To present our trial using a combination of the human acellular dermal matrix （HADM） implant and an interpositional omentum flap to repair giant abdominal wall defects after extensive tumor resection. METHODS： Between February and October of 2007, three patients with giant defects of the abdominal wall after extensive tumor resection underwent reconstruction with a combination of HADN and omentum flap. Postoperative morbidities and signs of herniation were monitored. RESULTS： The abdominal wall reconstruction was successful in these three patients, there was no severe morbidity and no signs of herniation in the follow-up period. CONCLUSION： The combination of HADM and omentum flap offers a new, safe and effective alternative to traditional forms in the repair of giant abdominal wall defects. Further analysis of the long-term outcome and more cases are needed to assess the reliability of this technique.

Differentiation of mesenchymal stem cells into neuronal cells on fetal bovine acellular dermal matrix as a tissue engineered nerve scaffold

The purpose of this study was to assess fetal bovine acellular dermal matrix as a scaffold for supporting the differentiation of bone marrow mesenchymal stem cells into neural cells fol-lowing induction with neural differentiation medium. We performed long-term, continuous observation of cell morphology, growth, differentiation, and neuronal development using several microscopy techniques in conjunction with immunohistochemistry. We examined speciifc neu-ronal proteins and Nissl bodies involved in the differentiation process in order to determine the neuronal differentiation of bone marrow mesenchymal stem cells. The results show that bone marrow mesenchymal stem cells that differentiate on fetal bovine acellular dermal matrix display neuronal morphology with unipolar and bi/multipolar neurite elongations that express neuro-nal-speciifc proteins, includingβIII tubulin. The bone marrow mesenchymal stem cells grown on fetal bovine acellular dermal matrix and induced for long periods of time with neural differen-tiation medium differentiated into a multilayered neural network-like structure with long nerve ifbers that was composed of several parallel microifbers and neuronal cells, forming a complete neural circuit with dendrite-dendrite to axon-dendrite to dendrite-axon synapses. In addition, growth cones with filopodia were observed using scanning electron microscopy. Paraffin sec-tioning showed differentiated bone marrow mesenchymal stem cells with the typical features of neuronal phenotype, such as a large, round nucleus and a cytoplasm full of Nissl bodies. The data suggest that the biological scaffold fetal bovine acellular dermal matrix is capable of supporting human bone marrow mesenchymal stem cell differentiation into functional neurons and the subsequent formation of tissue engineered nerve.

Chicken collagen hydrolysates differentially mediate anti-inflammatory activity and type I collagen synthesis on human dermal fibroblasts

Collagen is a major extracellular matrix protein.Given the potential anti-inflammatory and antioxidant profiles of these bioactive compounds,there has been increasing interest in using collagen derived peptides and peptide-rich collagen hydrolysates for skin health,due to their immunomodulatory,antioxidant and proliferative effects on dermal fibroblasts.However,all hydrolysates are not equally effective in exerting the beneficial effects;hence,further research is needed to determine the factors that improve the therapeutic applicability of such preparations.We used different enzymatic conditions to generate a number of different collagen hydrolysates with distinct peptide profiles.We found that the use of two rather than one enzyme for hydrolysis generates a greater abundance of low molecular weight peptides with consequent improvement in bioactive properties.Testing these hydrolysates on human dermal fibroblasts showed distinct actions on inflammatory changes,oxidative stress,type I collagen synthesis and cellular proliferation.Our findings suggest that different enzymatic conditions affect the peptide profile of hydrolysates and differentially regulate their biological activities and potential protective responses on dermal fibroblasts.

Effect of Dermal Exposure to Paraphenylenediamine and Linear Alkylbenzene Sulphonate in Guinea Pigs

To study the effects of paraphenylenediamine （PPD） and linear alkylbenzene sulphonate （LAS） alone and in combination on the skin. Methods Forty-eight guinea pigs were divided equally into 4 groups and exposed to PPD （4 mg/kg）, LAS （12 mg/kg） and PPD （4 mg/kg） plus LAS （12 mg/kg） for 30 days. The biochemical parameters such as acid phosphatase, gtutathione-s-transferase, glutathione peroxidase, glutathione, lipid peroxidafion and histamine contents in exposed skin were estimated. The histopathological examination of the exposed skin was also carried out. Results The skin enzymes, lipid peroxidation, and histamine increased while glutathione decreased in skin. The simultaneously exposed group showed additive toxic effects. The histopathological examination showed severe hyperkeratosis, thickening of collagen fibres and vacuolisation of epidermal cells in PPD plus LAS exposed skin. Conclusion The findings of the present study suggest that simultaneous exposure to PPD and LAS has additive toxic effects.

The Versatility of Acellular Fetal Bovine Dermal Matrix for Head and Neck Surgical Reconstruction in Children

Objectives: To describe the versatility of acellular fetal bovine dermal matrix as an alternative to human cadaveric allograft for head and neck reconstructive procedures in children. Study Design: Case series with chart review. Methods: A database of pediatric operative procedures was queried for the use of acellular fetal bovine dermal matrix over a 16-month period. Indications for reconstruction were assessed and initial parental and surgeon satisfaction with the product were noted. Results: During the time period of 3/2012 and 7/2013 a total of 8 reconstructive procedures were performed on pediatric patients using acellular fetal bovine dermal matrix. Indications for use varied and included open and transnasal endoscopic repair of encephaloceles and soft tissue reconstructions including lateral pharyngeal wall repair, cleft palate repair, and facial recontouring operations. Acellular fetal bovine dermal matrix had a subjectively increased ease of use as compared to the surgeon’s prior experience with human cadaveric acellular dermis. Every parent vocalized a greater comfort level with the use of a bovine product over the alternative of human cadaveric tissue. The cost of acellular fetal bovine dermal matrix is slightly lower than the cost of human cadaveric acellular dermis. Conclusions: Acellular fetal bovine dermal matrix appears to be an acceptable alternative to human cadaveric acellular dermis for various forms of head and neck soft tissue reconstruction in children. Further prospective studies are warranted to assess for any differences in the long-term efficacy of this product as compared to other forms of allograft reconstruction.

Visceral leishmaniasis: An immunological viewpoint on asymptomatic infections and post kala azar dermal leishmaniasis

Elimination of visceral leishmaniasis is a priority programme in Indian subcontinent.The World Health Organization has set a new target to eliminate kala-azar by the year 2020 as previous target elimination year(2015) has passed.The elimination programme has successfully curbed the rate of infection in endemic regions; however, there are still few challenges in its route.The current drug control regime is extremely limited and comprises only two(amphotericin B and miltefosine) drugs, which are also susceptible for parasites resistance.Moreover, these drugs do not produce sterile cure, and cured patients may develop post kala-azar dermal leishmaniasis even after a decade of cure leaving behind a potent source of parasitic reservoirs for further disease transmission.A significant proportion of endemic population remain seropositive but aymptomatic for many years without any clinical symptom that serve as latent parasitic reservoirs.The lack of tools to identify live parasites in asymptomatic infections and there association in disease transmission, parameters of sterile cure along with post kala-azar dermal leishmaniasis progression remain a major threat in its elimination.In this review, we discuss the potential of host immune inhibitory mechanisms to identify immune correlates of protective immunity to understand the mystery of asymptomatic infections, sterile cure and post kala azar dermal leishmaniasis.

Application of acellular dermal matrix for intestinal elongation in animal models

AIM:To investigate the eff icacy of acellular dermal matrix(ADM) for intestinal elongation in animal models.METHODS:Japanese white big-ear rabbits(n = 9) and Wuzhishan miniature pigs(n = 5) were used in the study.Home-made and commercial ADM materials were used as grafts,respectively.A 3-cm long graft was interposed in continuity with the small bowel and a sideto-side anastomosis,distal to the graft about 3-4 cm,was performed.The animals were sacrificed at 2 wk,4 wk,8 wk and 3 mo after surgery and the histological changes were evaluated under light microscope and electron microscope.RESULTS:The animals survived after the operation with no evidence of peritonitis and sepsis.Severe ad-hesions were found between the graft and surrounding intestine.The grafts were completely absorbed within postoper ative two or three months except one.Histological observ ation showed inflammation in the grafts with fibrinoid necroses,infiltration of a large amount of neutrophils and leukomonocytes,and the degree varied in different stages.The neointestine with wellformed structures was not observed in the study.CONCLUSION:It is not suitable to use acellular dermal matrix alone as a scaffold for the intestinal elongation in animal models.

Screening and analysis of differentially expressed genes of dermal papillae cells with aggregative behavior

Objective: To screen and clone differentially expressed genes of dermal papillae cells (DPC) with aggregative behavior, and to explore the molecular mechanism of their aggregation. Methods: Total RNAs were extracted from DPC with and without aggregative behavior and double strand cDNAs were synthesized by using SMART cDNA synthesis, respectively. The cDNA fragments of differentially expressed genes in DPCs with aggregative behavior were isolated by suppression subtractive hybridization. Positive clones were screened by PCR method and verified by cDNA dot blot, Northern blot and then analyzed through homologous retrieving. Results: A subtractive cDNA library of DPC with aggregative behavior has been successfully constructed. The result of screening and cloning of the library showed that, DPC with aggregative behavior could expresse genes related to homologous aggregation, proliferation and cycle control, including known genes (capping protein, paladin, vascular endothelial growth factor), hematopoietic stem/progenitor cells (HSPC) related clone (HSPC011 and HSPC016) and a new gene. Conclusion: The construction of subtracted library of DPC lays solid foundation for screening and cloning new and specific genes related to aggregative behavior of DPC. Several genes might be cooperatively involved in the homologous aggregation, proliferation and cycle control of DPC. Among these genes, capping protein and palladin might be closely related to the aggregative behavior of dermal papilla cells, and VEGF and HSPC related clone would be responsible for the status of higher proliferation of dermal papilla cells.

The Polypeptide in Chlamys farreri can protect human dermal fibroblasts from ultraviolet B damage

To investigate the effect of polypeptide from Chlamys farreri (PCF) on NHDF in vitro, we modeled oxidative damage on normal human dermal fibroblasts (NHDF) exposed to ultraviolet B (UVB). In this study, 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydro-genase (LDH) were tested to measure cell viability. Enzymes including superoxide dismutase (SOD), glu-tathione peroxidase (GSH-PX), catalase (CAT) and xanthine oxidase (XOD) were determined biochemically. Total antioxidative capacity (T-AOC) and anti-superoxide anion capacity (A-SAC) were also determined. Ultrastructure of fibroblasts was observed under transmission electron microscope. The results showed that: UVB (1.176×10-4 J/cm2) suppressed the growth of fibroblasts and the introduction of PCF (0.25%-l%) before UVB reduced the suppression in a concentration-dependent manner. PCF could enhance the activities of SOD, GSH-PX and T-AOC as well as A-SAC. Also PCF could inhibit XOD activity, while it did not affect CAT activity. Ultrastructure of fibroblasts were damaged after UVB irradiation, concentration-dependent PCF reduced the destructive effect of UVB on cells. These results indicated that PCF can protect human dermal fibroblasts from being harmed by UVB irradiation via its antioxidant pro-erty.