Skin test and tick immune status in susceptible and resistant cattle in Brazil

A cutaneous hypersensitivity test (CHT) was used to correlate host resistance to ticks and type of reaction elicited to unfed larval extract-ULE of the cattle tick Boophilus microplus in European and Indian cattle. Twenty calves were separated into four groups of five animals each: naïve or preinfested Indian or European cattle. CHT was induced by intradermal inoculation of 0.1 ml of ULE cattle tick B. microplus (50 μg protein) in the calf ear. Ear thickness was measured using calipers before and 10 min, 1, 2, 6, 18, 24, 48, 72, 96, and 144 h postinoculation (PI). Preinfested European calves showed only an immediate type reaction with maximum response (75% increase in ear thickness) at 10 min PI. On the other hand, preinfested Indian calves presented an immediate response with maximum reaction (70% increase in ear thickness) between 10 min and one hour PI, and a delayed type reaction at 72 h PI (60% increase in ear thickness). These results point out the crucial role of the cellular immune response of cattle in the expression of resistance to cattle tick B. microplus. Skin test might be useful in the ranking of cattle according to the susceptibility/resistance to ticks.

Evaluation of skin hydration after exposition to the aqueous and hydroalcoholic bases and silicone emulsion

Several dermocosmetic bases even without active substances, can increase the cutaneous hydration, resulting in a beneficial effect to the skin. The evidence and interpretation of possible hydration effect of formulations in the skin can be carried through by means of histopathological and histomorphometrical evaluation, a time that allows the analysis of the epithelial tissue, of dermis and also of the cellular characteristics. The objective of this research was to evaluate the skin hydration after exposition to the aqueous and hydroalcoholic bases and silicone emulsion. Swines had areas submitted to treatments during 15 days with three different formulations (F1 - aqueous gel, F2 - hydroalcoholic gel and F3 - silicone emulsion). By means of histometric and histopathological techniques were gotten the thickness of the epidermis and stratum corneum. Comparison of means was done using ANOVA followed by the Tukey test. The F1 provoked significant increase in the thickness of the epidermis. The formulaton F2 provoked significant reduction in the thickness of the epidermis and stratum corneum. F3 not presented significant difference in this structures. According to the study, the type of base chosen intervenes with the skin hydration.

Tissue engineering: Using collagen type i matrix for bone healing of bone defects

Among the many tissues in the human body, bone has been considered as a powerful marker for regeneration and its formation serves as a prototype model for tissue engineering based on morphogenesis. Therefore, collagen type I is one of the most useful biomaterials used in tissue engineering as extracellular matrix components capable to promote bone healing. The literature reveals excellent biocompatibility and safety due to its biological characteristics, such as biodegradability and weak antigenicity, making collagen type I the primary resource in medical applications. Thus, it was also used for tissue engineering including skin replacement, bone substitutes, and artificial blood vessels and valves. The authors describe the treatment of an abscessed apical periodontal cyst and show good outcomes of bone healing, using tissue engineering, as collagen type I matrix. © 2013 by Mutaz B. Habal, MD.

The carreau-yasuda fluids: a skin friction equation for turbulent flow in pipes and kolmogorov dissipative scales

In this work the turbulent flow of the Non-Newtonian Carreau-Yasuda fluid will be studied. A skin friction equation for the turbulent flow of Carreau-Yasuda fluids will be derived assuming a logarithmic behavior of the turbulent mean velocity for the near wall flow out of the viscous sub layer. An alternative near wall characteristic length scale which takes into account the effects of the relaxation time will be introduced. The characteristic length will be obtained through the analysis of viscous region near the wall. The results compared with experimental data obtained with Tylose (methyl hydroxil cellulose) solutions showing good agreement. The relations between scales integral and dissipative obtained for length, time, velocity, kinetic energy, and vorticity will be derived for this type of fluid. When the power law index approach to unity the relations reduces to Newtonian case.

Rheological, mechanical, and bioadhesive behavior of hydrogels to optimize skin delivery systems

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Molecular analysis of community-acquired methicillin-resistant Staphylococcus aureus isolated from skin and soft tissue infections, Botucatu Medical School, Brazil

Community acquired methicillin Staphylococcus aureus (CA-MRSA) was first reported in 1981, infecting people without risk factors. These strains harbor the Staphylococcal Cassette Chromosome mec (SCCmec) type IV, which contains the mecA gene codifying for methicillin resistance. CA-MRSA strains usually carry PVL (Panton-Valentine Leukocidin), a virulence factor responsible for tissue invasion, causing systemic infections and leading to serious complications. The aims of this work were to detect the mecA gene, SCCmec characterization and to detect the PVL gene of the S. aureus strains isolated from patients diagnosed with skin and soft tissue infections attending the Dermatology Service, of the Botucatu Medical School, Brazil. Among 127 collected samples, 66 (51.9%) were S. aureus and, from these, 7 (10.6%) harbored mecA gene, 3 (42%) with cassette type IV, and none of these samples carried the PVL gene, but it was detected in 10 (15.1%) samples of S. aureus methicillin sensitive (MSSA). Our study suggests the S. aureus strains that harbor PVL gene and MRSA are present in the community as important pathogens.

Community-associated methicillin-resistant Staphylococcus aureus in non-outbreak skin infections

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Community-associated methicillin-resistant Staphylococcus aureus in non-outbreak skin infections

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

In Vitro Development and Cell Allocation After Aggregation of Syngeneic Wild Type and Fluorescence-Expressing Bovine Cloned Embryos

Background: The in vitro production (IVP) of embryos by in vitro fertilization or cloning procedures has been known to cause epigenetic changes in the conceptus that in turn are associated with abnormalities in pre- and postnatal development. Handmade cloning (HMC) procedures and the culture of zona-free embryos in individual microwells provide excellent tools for studies in developmental biology, since embryo development and cell allocation patterns can be evaluated under a wide range of embryo reconstruction arrangements and in in vitro embryo culture conditions. As disturbances in embryonic cell allocation after in vitro embryo manipulations and unusual in vivo conditions during the first third of pregnancy appear to be associated with large offspring, embryo aggregation procedures may allow a compensation for epigenetic defects between aggregated embryos or even may influence more favorable cell allocation in embryonic lineages, favoring subsequent development. Thus, the aim of this study was to evaluate in vitro embryo developmental potential and the pattern of cell allocation in blastocysts developed after the aggregation of handmade cloned embryos produced using syngeneic wild type and/or transgenic somatic cells. Materials, Methods & Results: In vitro-matured bovine cumulus-oocyte complexes (COC) were manually bisected after cumulus and zona pellucida removal; then, two enucleated hemi-oocytes were paired and fused with either a wild type (WT) or a GFP-expressing (GFP) fetal skin cell at the 11th and 19th passages, respectively. Following chemical activation, reconstructed cloned embryos and zona-free parthenote embryos were in vitro-cultured in microwells, for 7 days, either individually (1 x 100%) or after the aggregation of two structures (2 x 100%) per microwell, as follows: (G1) one WT cloned embryo; (G2) two aggregated WT embryos; (G3) one GFP cloned embryo; (G4) two aggregated GFP embryos; (G5) aggregation of a WT embryo and a GFP embryo; (G6) one parthenote embryo; or (G7) two aggregated parthenote embryos. Fusion (clones), cleavage (Day 2), and blastocyst (Day 7) rates, and embryonic cell allocation were compared by the. 2 or Fisher tests. Total cell number (TCN) in blastocysts was analyzed by the Student's test (P < 0.05). Fusion and cleavage rates, and cell allocation were similar between groups. On a per WOW basis, development to the blastocyst stage was similar between groups, except for lower rates of development seen in G3. However, when based on number of embryos per group (one or two), blastocyst development was higher in G1 than all other groups, which were similar between one another. Cloned GFP embryos had lower in vitro development to the blastocyst stage than WT embryos, which had more TCN than parthenote or aggregated chimeric WT/GFP embryos. Aggregated GFP embryos had fewer cells than the other embryo groups. Discussion: The in vitro development of GFP cloned embryos was lower than WT embryos, with no effects on cell allocation in resulting blastocysts. Differences in blastocyst rate between groups were likely due to lower GFP-expressing cell viability, as GFP donor cells were at high population cell doublings when used for cloning. On a per embryo basis, embryo aggregation on Day 1 resulted in blastocyst development similar to non-aggregated embryos on Day 7, with no differences in cell proportion between groups. The use of GFP-expressing cells was proven a promising strategy for the study of cell allocation during embryo development, which may assist in the elucidation of mechanisms of abnormalities after in vitro embryo manipulations, leading to the development of improved protocols for the in vitro production (IVP) of bovine embryos.

A cross-sectional study on canine Leishmania (L.) infantum chagasi infection in Amazonian Brazil ratifies a higher prevalence of specific IgG-antibody response than delayed-type hypersensitivity in symptomatic and asymptomatic dogs

This was a cross-sectional study which analyzed the prevalence and the clinical and immunological spectrum of canine Leishmania (L.) infantum chagasi infection in a cohort of 320 mongrel dogs living in an endemic area of American visceral leishmaniasis in the Amazonian Brazil by using, mainly, the indirect fluorescence antibody test (IFAT-IgG) and the delayed-type hypersensitivity (DTH), and the parasite research by the popliteal lymph node aspiration. The IFAT and DTH reactivity recognized three different immune response profiles: (1) IFAT((+))/DTH(-) (107 dogs), (2) IFAT((-))/DTH(+) (18 dogs), and (3) IFAT((+))/DTH(+) (13 dogs), providing an overall prevalence of infection of 43 % (138/320). Thus, the specific prevalence of IFAT ((+)) /DTH ((-)) 33.4 % (107/320) was higher than those of IFAT ((-)) /DTH ((+)) 5.6 % (18/320) and IFAT ((+)) /DTH ((+)) 4.0 % (13/320). Moreover, the frequency of these profiles among 138 infected dogs showed that the IFAT ((+)) /DTH ((-)) rate of 77.5 % (107/138) was also higher than those of 13.0 % (18/138) of IFAT ((-)) /DTH ((+)) and 9.5 % (13/138) of IFAT ((+)) /DTH ((+)) rates. The frequency of asymptomatic dogs (76 %-105) was higher than those of symptomatic (16.6 %-23) and oligosymptomatic ones (7.4 %-10). A total of 16 (11.6 %) L. (L.) i. chagasi isolates were obtained from infected dogs, all from the IFAT ((+)) /DTH ((-)) profile: 41 % (9/22) from symptomatic, 33.3 % (3/9) from oligosymptomatic, and 5.2 % (4/76) from asymptomatic dogs. These findings strongly suggested that despite the higher frequency of asymptomatic dogs (76 %-105), the majority (72.4 %-76) was characterized by the IFAT ((+)) /DTH ((-)) profile with a doubtful immunogenetic resistance against infection.

Lack of signaling by IL-4 or by IL-4/IL-13 has more attenuating effects on Leishmania amazonensis dorsal skin - than on footpad-infected mice

Lesion development in tegumentary leishmaniasis is markedly influenced by the inoculation site and the type and number of injected infective forms. This and the yet unclear contribution of Th2 cytokines as susceptibility factors to Leishmania amazonensis infection prompted us to investigate the roles of IL-4, IL-13 and IL-10 on C57BL/6 and BALB/c mice infected in the footpad (paw) or rump with low-dose L. amazonensis purified-metacyclics. Wild-type (WT) mice of either strain developed, in the rump, a single large ulcerated lesion whereas paw lesions never ulcerated and were much smaller in C57BL/6 than in BALB/c mice. However, rump-inoculated IL-4-deficient (IL-4(-/-))C57BL/6 mice did not develop any visible lesions although parasites remained in the dermis and lymph nodes, even after systemic IL-10-receptor blocking. By comparison, all IL-4(-/-) BALB/c mice developed rump ulcers. Strikingly, only 30% of rump-infected IL-4R alpha(-/-) BALB/c mice developed lesions. IL-4(-/-) mice had higher IFN-gamma and lower IL-10 and IL-13 levels than WT mice. Paw-infected IL-4R alpha(-/-) BALB/c mice developed minimal paw lesions. While other factors contributing to L amazonensis susceptibility cannot be discounted, our results indicate that absent signalling by IL-4 or by IL-4/IL-13 have more intense attenuating effects on rump than on paw lesions but do not eradicate parasitism. (C) 2011 Elsevier Inc. All rights reserved.

Atopic dermatitis: correlation between non-damaged skin barrier function and disease activity

Background Atopic dermatitis (AD) is a chronic dermatosis, predominant in childhood, characterized by pruritus and eczematous-type lesions with xerosis as the prominent clinical sign. Objectives To analyze the correlation between biophysical measurements of skin barrier function and other assessment criteria of clinical severity according to Rajka and Langelands criteria. Methods Biophysical measurements [transepidermal water loss (TEWL) and corneometry] were obtained from 120 patients with the diagnosis of AD. Serum levels of IgE were also evaluated. Results A significant correlation between corneometry, TEWL, and clinical severity of AD was found. Data showed an inverse correlation between corneometry, TEWL, and AD severity, and a significant difference (P < 0.001) between mean of corneometry and TEWL and AD severity (mild, moderate, and severe). As for IgE levels, corneometry had significant negative correlation, in contrast with TEWL, which showed a significant positive correlation (P < 0.001). Conclusion Biophysical measurements of skin barrier in non-lesional skin of AD may work as an evaluation factor for AD severity.

Association of acanthosis nigricans and skin tags with insulin resistance

Insulin resistance is a metabolic disorder in which target cells fail to respond to normal levels of circulating insulin. Insulin resistance has been associated with presence of acanthosis nigricans and acrochordons. It is known that early diagnosis and early initial treatment are of paramount importance to prevent a series of future complications. These dermatoses may represent an easily identifiable sign of insulin resistance and non-insulin-dependent diabetes.

High Prevalence of Skin Disorders among HTLV-1 Infected Individuals Independent of Clinical Status

Background Human T-cell lymphotropic virus type 1 (HTLV-1) infection can increase the risk of developing skin disorders. This study evaluated the correlation between HTLV-1 proviral load and CD4+ and CD8+ T cells count among HTLV-1 infected individuals, with or without skin disorders (SD) associated with HTLV-1 infection [SD-HTLV-1: xerosis/ichthyosis, seborrheic dermatitis or infective dermatitis associated to HTLV-1 (IDH)]. Methods A total of 193 HTLV-1-infected subjects underwent an interview, dermatological examination, initial HTLV-1 proviral load assay, CD4+ and CD8+ T cells count, and lymphproliferation assay (LPA). Results A total of 147 patients had an abnormal skin condition; 116 (79%) of them also had SD-HTLV-1 and 21% had other dermatological diagnoses. The most prevalent SD-HTLV-1 was xerosis/acquired ichthyosis (48%), followed by seborrheic dermatitis (28%). Patients with SD-HTLV-1 were older (51 vs. 47 years), had a higher prevalence of myelopathy/tropical spastic paraparesis (HAM/TSP) (75%), and had an increased first HTLV-1 proviral load and basal LPA compared with patients without SD-HTLV-1. When excluding HAM/TSP patients, the first HTLV-1 proviral load of SD-HTLV-1 individuals remains higher than no SD-HTLV-1 patients. Conclusions There was a high prevalence of skin disorders (76%) among HTLV-1-infected individuals, regardless of clinical status, and 60% of these diseases are considered skin disease associated with HTLV-1 infection.