Effect of the iontophoresis of a chitosan gel on doxorubicin skin penetration and cytotoxicity

The aim of this work was to investigate doxorubicin (DOX) percutaneous absorption and retention in the skin following iontophoresis. The convective flow contribution to the overall electrotransport of DOX was also elucidated for a non-ionic hyd roxyethylcellulose gel and a cationic chitosan gel. Moreover, the cytotoxicity of DOX and its formulations, with and without low electrical current, was verified. It was observed that iontophoresis of DOX significantly increased the skin permeation and retention of the drug. In addition, the electroosmotic flow was dramatically reduced when DOX was added to the non-ionic gel, thereby indicating that the drug interacted with negative charges in the skin. Interestingly, electroosmosis was also significantly reduced when the iontophoresis was performed in the presence of the chitosan gel, but in the absence of DOX. Consequently, the transport of an electroosmotic marker from this gel almost disappeared when the positively charged drug was added to the cationic gel. These results indicated that chitosan appeared to interact with negative charges in the skin. Hence, this carrier not only reduced electroosmotic flow, but also released DOX from ionic interactions with these sites and improved its diffusion to deeper skin layers. The application of the low electrical current directly to melanoma cells increased DOX cytotoxicity by nearly three-fold, which was probably due to membrane permeation. (c) 2008 Elsevier B.V. All rights reserved.

Assessment of the percutaneous penetration of cisplatin: The effect of monoolein and the drug skin penetration pathway

It was intended to examine the in vitro penetration of cisplatin (CIS) through porcine skin in the presence of different concentrations of monoolein (MO) as well as to verify the main barrier for CIS skin penetration. In vitro skin penetration of CIS was studied from propylene glycol (PG) solutions containing 0%, 5%, 10%, and 20% of MO using Franz-type diffusion cell and porcine ear skin. Pretreatment experiments with MO and experiments with skin without stratum corneum (SC) were also carried out. Skin penetration studies of CIS showed that the presence of MO doubled the drug permeation through the intact skin. However, permeation studies through the skin without SC caused only a small enhancement of CIS permeation compared to intact skin. Moreover, pretreatment of skin with MO formulations did not show any significant increase in the flux of the drug. In conclusion, MO did not act as a real penetration enhancer for CIS, but it increased the drug partition to the receptor solution improving CIS transdermal permeation. The absence of improvement in drug permeation by MO pretreatment and by the removal of SC indicates that the SC is not the main barrier for the permeation of the metal coordination compound. (c) 2009 Elsevier B.V. All rights reserved.

Collagen and Elastic Content of Abdominal Skin After Surgical Weight Loss

Collapsed skin folds after bariatric weight loss are often managed by plastic procedures, but changes in dermal composition and architecture have rarely been documented. Given the potential consequences on surgical outcome, a prospective histochemical study was designed. The hypothesis was that a deranged dermal fiber pattern would accompany major changes in adipose tissue. Female surgical candidates undergoing postbariatric abdominoplasty (n = 40) and never obese women submitted to control procedures (n = 40) were submitted to double abdominal biopsy, respectively in the epigastrium and hypogastrium. Histomorphometric assessment of collagen and elastic fibers was executed by the Image Analyzer System (Kontron Electronic 300, Zeiss, Germany). Depletion of collagen, but not of elastic fibers, in cases with massive weight loss was confirmed. Changes were somewhat more severe in epigastrium (P = 0.001) than hypogastrium (P = 0.007). Correlation with age did not occur. (1) Patients displayed lax, soft skin lacking sufficient collagen fiber network. (2) Elastic fiber content was not damaged, and was even moderately increased in epigastrium; (3) Preoperative obesity negatively correlated with hypogastric collagen concentration; (4) Future studies should pinpoint the roles of obesity, and especially of massive weight loss, on dermal architecture and response to surgery.

Pentoxifylline modifies three-dimensional collagen lattice model contraction and expression of collagen types I and III by human fibroblasts derived from post-burn hypertrophic scars and from normal skin

Fibroblasts are thought to be partially responsible for the persisting contractile forces that result in burn contractures. Using a monolayer cell culture and fibroblast populated collagen lattice (FPCL) three-dimensional model we subjected hypertrophic scar and non-cicatricial fibroblasts to the antifibrogenic agent pentoxifylline (PTF - 1 mg/mL) in order to reduce proliferation, collagen types I and III synthesis and model contraction. Fibroblasts were isolated from post-burn hypertrophic scars (HSHF) and non-scarred skin (NHF). Cells were grown in monolayers or incorporated into FPCL`s and exposed to PTF. In monolayer, cell number proliferation was reduced (46.35% in HSHF group and 37.73% in NHF group, p < 0.0001). PTF selectively inhibited collagen III synthesis in the HSHF group while inhibition was more evident to type I collagen synthesis in the NHF group. PTF also reduced contraction in both (HSHF and NHF) FPCL. (C) 2009 Elsevier Ltd and ISBI. All rights reserved.

Perineural Invasion in Aggressive Skin Carcinomas of the Head and Neck

Introduction: Perineural invasion is a well-recognized form of cancer dissemination. However, it has been reported only in few papers concerning cutaneous carcinomas ( basal cell, BCC, and squamous cell, SCC). Moreover, the incidence is considered to be very low. Niazi and Lambert [Br J Plast Surg 1993; 46: 156-157] reported only 0.18% of perineural invasion among 3,355 BCCs. It is associated with high-risk subtypes, as morphea-like, as well as with an increased risk of local recurrence. No paper was found in the literature looking for perineural invasion in very aggressive skin cancers with skull base extension, with immunohistochemical analysis. Methods: This is a retrospective review, including 35 very advanced skin carcinomas with skull base invasion (24 BCCs and 11 SCCs, operated on at a single institution from 1982 to 2000). Representative slides were immunohistochemically evaluated with antiprotein S-100, in order to enhance nerve fibers and to detect perineural invasion. The results were compared to 34 controls with tumors with a good outcome, treated in the same time frame at the same Institution. Results: Twelve (50.0%) of the BCCs with skull base invasion had proven perineural invasion, as opposed to only 1 (4.6%) of the controls, and this difference was statistically significant (p < 0.001). Regarding SCCs, 7 aggressive tumors (63.6%) showed perineural invasion compared to only 1 (10.0%) of the controls, but this difference did not reach significance (p=0.08), due to the small number of cases. Conclusions: In this series, it was demonstrated that immunohistochemically detected perineural invasion was very prevalent in advanced skin carcinomas. In addition, it was statistically associated with extremely aggressive BCCs with skull base invasion. Copyright (c) 2008 S. Karger AG, Basel

A Randomized Trial of a Skin Sealant to Reduce the Risk of Incision Contamination in Cardiac Surgery

Background. Immobilizing skin microbes is a rational approach to reducing contamination of surgical sites by endogenous microorganisms. Methods. This randomized, controlled, parallel-group, multicenter, open-label clinical trial (ClinicalTrials.gov NCT00467857) enrolled 300 adults scheduled for elective coronary artery bypass graft surgery. Patients received iodine-based skin preparations followed by a cyanoacrylate-based skin sealant or skin preparations alone. Microbiological samples collected from sternal and graft incision sites immediately before any skin preparation, at the wound border after skin incision, and at the incision after fascial closure were evaluated quantitatively. Results. In evaluable patients, mean microbial counts in collected samples increased at the sternal site after fascial closure compared with after skin incision by 0.37 log(10) colony-forming units (CFU)/mL in the skin sealant group (n = 120) and by 0.57 log10 CFU/mL in the control group (n = 132) (p = 0.047, Wilcoxon rank sum test). At the graft site, mean microbial counts increased by 0.09 (n = 119) and 0.27 (n = 127) log(10) CFU/mL, respectively (p = 0.037). There was a 35.3% relative risk reduction in surgical site infection (SSI) occurring in the skin sealant group (9 of 146 patients, 6.2%) versus the control group (14 of 147 patients, 9.5%). In obese patients (body mass index [BMI] > 30.0 to <= 37.0 kg/m(2)), the relative risk reduction for SSI associated with skin sealant was 83.3%. Conclusions. Pretreatment with skin sealant protects against contamination of the surgical incision by migration of skin microbes. Further data are needed to confirm the impact of this technology on SSI rates in clinical practice. (Ann Thorac Surg 2011;92:632-7) (C) 2011 by The Society of Thoracic Surgeons ADULT CARDIAC

Comparative effects of pimecrolimus cream vehicle and three commercially available moisturizers on skin hydration and transepidermal water loss

Background: Hydration and integrity of the horny layer is essential to normal skin function. Objective: Comparison of the hydrating properties of three moisturizers with pimecrolimus cream vehicle. Methods: Four test preparations (high-quality skin cream, cold cream emulsion, emollient oil, pimecrolimus cream vehicle) were applied to four different regions of the forearms and legs. Transepidermal water loss (TEWL) was assessed by evaporimetry at baseline, and 3 and 6 hours after arm application, and electrical capacitance was assessed by corneometry at baseline, and 1, 2, 3 and 6 hours after leg application. Results: Corneometry assessment - in terms of efficacy in moisturizing the skin, test preparations were ranked (best to worst): high-quality skin cream (45.9 arbitrary units versus 75.3; p < 0.001) > pimecrolimus vehicle cream (46.6 versus 61.5; p < 0.001) > emollient oil (43.5 versus 54.8; p = 0.006) > cold cream emulsion (44.8 versus 49.9; p = 0.738). Untreated skin (control) had a mean capacitance of 44.8 units at baseline and 48.5 units at endpoint. Evaporimetry (assessment of TEWL) revealed no significant differences between control and any test preparation at any timepoint. Conclusions: Pimecrolimus cream vehicle has skin hydration properties comparable with highly effective commercially available products. No test preparation had a significant effect on TEWL.

The effects of topical isoflavones on postmenopausal skin: Double-blind and randomized clinical trial of efficacy

Objective: The aim of this study was to evaluate the effects of estrogen and isoflavones on postmenopausal skin morphological parameters. Study design: A randomized, double-blind, estrogen-controlled trial was performed on postmenopausal women treated in the Gynecology Department of the Federal University of Sao Paulo. This study was designed to analyze the effects of topical administration of estradiol and isoflavones on facial skin for 24 weeks. The participants were divided into two groups: G1-17-betaestradiol 0.01% (n = 18) and G2-isoflavones 40% (genistein 4%, n = 18). Skin biopsies were performed on each patient before and after the treatment. The skin samples were processed for histological analysis, stained with haematoxylin and eosin, and examined using light microscopy. Results: After 24 weeks of treatment, the estradiol group had a significant increase in skin parameters analyzed compared to the isoflavone group and to the baseline measurements: epidermal thickness (a 75% increase in the estrogen group and 20% in the isoflavone group), number of dermal papillae (a rise of 125% with estrogen, no significant gain with isoflavones), fibroblasts (a 123% accretion with estradiol, no significant gain with isoflavones), and vessels (a 77% increase with estrogen and 36% with isoflavones). Conclusion: Our data suggest that estrogens may have a stronger effect on histomorphometrical parameters than isoflavones. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

Skin Coverage of the Middle-Distal Segment of the Leg With a Pedicled Perforator Flap

Objective: This is a clinical study of our experience using pedicle perforator flaps to cover skin defects in the middle and distal segment of the leg. Design: Prospective study. Setting: University hospital. Patients/Intervention: Twenty-four patients underwent treatment of a skin defect in the middle or distal segment of the leg by means of pedicled flaps based on perforating arteries. The perforating arteries were located before the operation by means of echo-Doppler examination. The flaps were planned in propeller fashion (21 cases) and as advancement (three cases). Main Outcome Measurements: The results were evaluated according the origin of perforator flap, size of the flap, and donor area and viability of the flap. The success rate of the echo-Doppler to identify the location of perforator vessel was also evaluated. Results: In nine cases, the perforating vessels originated from the fibular artery, in 10 the posterior tibial artery, and in five the anterior tibial artery. The mean size of the flaps was 5 cm in width by 12 cm in length. The success rate using an echo-Doppler was 87%. The flaps were fully viable in 20 cases and partially viable in four cases. Conclusion: On the basis of these results, it is concluded that perforating flaps are a good choice of treatment for skin losses, especially in the distal segment of the leg, and could be an alternative option for the use of free microsurgical flaps.

Leishmania sp identification by PCR associated with sequencing of target SSU rDNA in paraffin-embedded skin samples stored for more than 30 years

Paraffin-embedded samples commonly stored at educational and research institutions constitute tissues banks for follow-up or epidemiological studies; however, the paraffin inclusion process involves the use of substances that can cause DNA degradation. In this study, a PCR protocol was applied to identify Leishmania strains in 33 paraffin-embedded skin samples of patients with American cutaneous leishmaniasis. DNA was obtained by the phenol-chloroform protocol following paraffin removal and then used in PCR or nested PCR based on the nucleotide sequence of the small subunit ribosomal RNA (SSU rDNA). The amplicons obtained were cloned and sequenced to determine the single nucleotide polymorphism that distinguishes between different Leishmania species or groups. This assay allowed to distinguish organisms belonging to the subgenus Viannia and identify L. (Leishmania) amazonensis and L. (L.) chagasi of the Leishmania subgenus. Of the 33 samples, PCR and nested PCR identified 91% of samples. After sequencing the PCR product of 26 samples, 16 were identified as L. (L.) amazonensis, the other 10 contain organisms belonging to the L. (Viannia) sub-genus. These results open a huge opportunity to study stored samples and promote relevant contributions to epidemiological studies.

Characterization of cytotoxic immune response in skin and mucosal lesions of paracoccidioidomycosis

Background: CD8+ T cells and natural killer (NK) cells are involved in the immune response against some pathogens. For this purpose, we investigated the in situ paracoccidioidomycosis (PCM) immune response addressing the participation of NK cells, CD8+ T cells, perforin and granzyme B expression. Methods: Sixty biopsies of PCM skin and mucosa were classified according to the presence of compact granulomas (G1), poorly organized granulomas (G2) and both kinds in the same lesion (G3). CD8+ T cells, NK cells, perforin and granzyme B were showed by immunohistochemistry. Results: CD8+ T cells were increased over NK cells in cutaneous G1 and G2 lesions. There was no difference regarding such cells in G3 lesions, although they were abundant in such lesions. In mucosa, CD8+ T cells were increased in number over NK cells in all groups. Granzyme B in skin increased in G2 and G3. The number of granzyme did not differ in mucosal lesions in the three groups. Conclusions: CD8+ T cells and NK cells play a role in PCM cutaneous and mucosal lesions. The predominance of CD8+ T cells over NK cells may represent an effective response against the fungi. Moreover, the high number of granzyme B expressing cells corroborates this possibility.

Factor XIIIa plus Dermal Dendrocyte Parasitism in American Tegumentary Leishmaniasis Skin Lesions

Dendritic cells belong to a family of antigen-presenting cells that are localized at the entry sites, such as skin and mucosa. Dendritic cells are related to immune surveillance function. The role of Langerhans cells in the pathogenesis of skin infectious diseases is well studied; however, there are few articles addressing involvement of factor XIIIa-positive dermal dendrocytes (FXIIIa+ DD) in such processes. FXIIIa+ DDs are bone marrow-monocytic lineage-derived cells and members of the skin immune system. Due to their immune phenotype and functional characteristics, they are considered complementary cells to Langerhans cells in the process of antigen presentation and inducing immune response. To verify the interaction between FXIIIa+ DD and Leishmania amastigotes, 22 biopsies of American tegumentary leishmaniasis (ATL) skin lesions were subjected to double staining technique with anti-factor XIIIa and anti-Leishmania antibodies. FXIIIa+ DDs were hypertrophic and abundant in the cutaneous reaction of ATL. FXIIIa+ DDs harboring parasites were observed in I I of 22 skin biopsies. The data obtained suggest that FXIIIa+ DD plays a role in the pathogenesis of ATL skin lesion as host cell, immune effector, and/or antigen-presenting cell.

Polymerase chain reaction compared to other laboratory findings and to clinical evaluation in the diagnosis of cutaneous tuberculosis and atypical mycobacteria skin infection

Cutaneous tuberculosis has re-emerged in the last 15 years together with the higher incidence of pulmonary tuberculosis and multidrug resistance. The choice for a single diagnostic tool among the many available today is a challenge. Our objective was to compare polymerase chain reaction (PCR) with other exams in the diagnosis of cutaneous tuberculosis and atypical mycobacteria skin infection. PCR and a set of five different exams were performed in 32 patients (34 samples of paraffin-embedded tissue) evaluated for 3 years in a university hospital, considering the response to mycobacterial infection treatment as a positive case. PCR was the most sensitive (88%) and specific (83%) exam. Culture, immunohistochemistry and acid-fast bacilli were not in agreement with clinical response to treatment. Although PCR is a useful tool, careful clinical exam is still the gold standard for the evaluation and treatment of cutaneous tuberculosis and mycobacteria skin infection.

Relationship of adhesion molecules expression with epithelial differentiation markers during fetal skin development

Background: Cadherins and integrins are important for maintenance of tissue integrity and in signal transduction during skin development. Distribution of these molecules in human skin development was investigated and associated with markers of differentiation, cytokeratins (CK) and involucrin (INV). Methods: Using immunohistochemistry expression of E- and P-cadherins, integrins beta-1 and -4, CK10, CK14 and INV was assessed in skin fragments of 10 human fetuses (gestational weeks ranged from 4 to 24, all weighing up to 500 g). Results: At initial phases of development, integrins beta-1 and -4 and E- and P-cadherins were present on epithelial cell membranes in all layers. CK14 and CK10 were expressed in all epithelial layers and INV weakly detected in the superficial layer. In more advanced stages, integrins were detected in all layers, but a marked polarized expression was seen in basal layer. E-cadherin was detected in all layers, but the cornified stratum and P-cadherin were observed in the lower layers. CK14 was expressed in basal layer, CK10 in suprabasal stratum and INV was observed in cornified layer. Conclusions: Cadherins and integrins are essential for skin development, being spatially and temporally regulated. Their expression is related with the expression of maturation markers of the epidermis.