scholarly journals Penetration of human skin by the cercariae of Schistosoma mansoni: an investigation of the effect of multiple cercarial applications

2003 ◽  
Vol 77 (1) ◽  
pp. 27-31 ◽  
Author(s):  
R.J. Ingram ◽  
A. Bartlett ◽  
M.B. Brown ◽  
C. Marriott ◽  
P.J. Whitfield
Keyword(s):  
Schistosoma Mansoni ◽  
Human Skin ◽  
Selective Advantage ◽  
Franz Cell ◽  
Orientation System ◽  
A Site ◽  
Specific Orientation

AbstractIt has previously been postulated that L-arginine emitted by penetrating Schistosoma mansoni cercariae serves as an intraspecific signal guiding other cercariae to the penetration site. It was suggested that penetrating in groups offers a selective advantage. If this hypothesis is correct and group penetration at one site on the host offers an advantage, it would follow that at such a site, successive groups of cercariae would be able to penetrate skin in either greater numbers or at a faster rate. This prediction was tested by the use of an in vitro model of cercarial penetration based on the Franz cell and using human skin. It was demonstrated that there was no increase in the percentage of cercariae able to penetrate the skin with subsequent exposures. Consequently, it seems unlikely that the release of L-arginine by cercariae during penetration could have evolved as a specific orientation system based on a selective advantage offered by group penetration.

scholarly journals Novel In Vitro Investigational Methods for Modeling Skin Permeation: Skin PAMPA, Raman Mapping

Pharmaceutics ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 803
Author(s):  
Stella Zsikó ◽  
Erzsébet Csányi ◽  
Anita Kovács ◽  
Mária Budai-Szűcs ◽  
Attila Gácsi ◽  
...  
Keyword(s):  
Human Skin ◽  
Skin Permeation ◽  
Regulatory Agencies ◽  
Raman Mapping ◽  
Early Screening ◽  
New Techniques ◽  
Franz Cell ◽  
Cell Measurement ◽  
Permeability Studies

The human skin is marked as a standard by the regulatory agencies in the permeation study of dermal formulations. Artificial membranes can substitute human skin to some extent. Academicians and pharmaceutical corporations are focusing their efforts on developing standardized protocols and safe, reliable options to substitute human skin for carrying out permeability studies. Our research aim was to study the applicability of new techniques in the case of different types of dermal formulations. The skin parallel artificial membrane permeability assay (PAMPA) method and Raman mapping were compared to the gold-standard Franz cell method. A hydrogel and two types of creams were investigated as the most generally used dermal preparations. The values of the diffused drug were closer to each other in PAMPA and Franz cell measurement. The diffused amount of drug showed the same order for the different formulations. These results correlate well with the results of Raman mapping. Our conclusions suggest that all early screening examinations can be performed with model tools such as skin PAMPA supplemented with methods like Raman mapping as a semi-quantitative method.

CuO nanoparticle penetration through intact and damaged human skin

2019 ◽  
Vol 43 (43) ◽  
pp. 17033-17039 ◽  
Author(s):  
Ilaria Zanoni ◽  
Matteo Crosera ◽  
Simona Ortelli ◽  
Magda Blosi ◽  
Gianpiero Adami ◽  
...  
Keyword(s):  
Human Skin ◽  
Cell Model ◽  
Cuo Nanoparticles ◽  
Franz Cell ◽  
Cuo Nanoparticle

Trans-dermal in vitro study of CuO nanoparticles in contact with intact and damaged human skin using a Franz cell model.

Penetration of mouse and human skin by cercariae of Schistosoma mansoni; immunological and histological observations

1980 ◽  
Vol 79 (1-3) ◽  
pp. 173-182
Author(s):  
H. V. Smith ◽  
A. McQueen ◽  
J. R. Kusel
Keyword(s):  
Schistosoma Mansoni ◽  
Human Skin ◽  
Bullous Pemphigoid ◽  
Skin Diseases ◽  
Mouse Skin ◽  
Pemphigus Vulgaris ◽  
Intercellular Substance ◽  
Human Cadaver Skin ◽  
Cadaver Skin

SynopsisSera from patients suffering from the autoimmune skin diseases pemphigus vulgaris and bullous pemphigoid were used to demonstrate the presence of intercellular substance (ICS) or bullous pemphigoid antigen (BPA) on the surface of the schistosomula of Schistosoma mansoni which had penetrated mouse and human cadaver skin, and mouse skin percutaneously. Both ICS and BPA were absent from mechanically transformed schistosomula or those formed in the peritoneal cavity of mice. Schistosomula which penetrated slowly through mouse or human skin in vitro, acquired more ICS or BPA than those which penetrated rapidly.During percutaneous infections of mice, schistosomula recovered from skin after 2h and 24h had acquired large quantities of these materials whereas those which were recovered from skin after 10min had no detectable ICS or BPA. These materials must be shed during subsequent migration since schistosomula from lungs and liver, and 7-week old adults do not possess them.Histological examination of both mouse and human skin revealed that the schistosomula remained in the epidermis for varying lengths of time. Schistosomula which remained there for more than 2h became vacuolated, whereas schistosomula which were present in the dermis at 2h appeared undamaged.On cercarial penetration of human skin, the granular layer of the epidermis became disrupted or condensed. The implications of these findings are discussed.

Desmosomal distribution in the epidermis of a non-contracting human skin equivalent

1992 ◽  
Vol 50 (1) ◽  
pp. 896-897
Author(s):  
L.X. Oakford ◽  
S.D. Dimitrijevich ◽  
R. Gracy
Keyword(s):  
Human Skin ◽  
Basal Layer ◽  
Skin Equivalent ◽  
Tissue Component ◽  
Intact Skin ◽  
Similar Sequence ◽  
Sequence Of Events ◽  
Suprabasal Keratinocytes ◽  
Human Skin Equivalent

In intact skin the epidermal layer is a dynamic tissue component which is maintained by a basal layer of mitotically active cells. The protective upper epidermis, the stratum corneum, is generated by differentiation of the suprabasal keratinocytes which eventually desquamate as anuclear comeocytes. A similar sequence of events is observed in vitro in the non-contracting human skin equivalent (HSE) which was developed in this lab (1). As a part of the definition process for this model of living skin we are examining its ultrastructural features. Since desmosomes are important in maintaining cell-cell interactions in stratified epithelia their distribution in HSE was examined.

In vitro schistosomicidal activity of Usnea steineri extract and its major constituent (+)-usnic acid against Schistosoma mansoni

Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
AIO Salloum ◽  
R Lucarini ◽  
MG Tozatti ◽  
J Medeiros ◽  
MLA Silva ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Usnic Acid ◽  
Major Constituent

Structure-Reactivity Relationships on Substrates and Inhibitors of the Lysine Deacylase Sirtuin 2 from Schistosoma Mansoni (SmSirt2)

2019 ◽  
Author(s):  
Daria Monaldi ◽  
Dante Rotili ◽  
Julien Lancelot ◽  
Martin Marek ◽  
Nathalie Wössner ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Human Cancer ◽  
Egg Laying ◽  
Human Cancer Cells ◽  
Parasite Survival ◽  
Survival And Reproduction ◽  
Emergence Of Resistance ◽  
First Time ◽  
Parasitic Life Cycle

The only drug for treatment of Schistosomiasis is Praziquantel, and the possible emergence of resistance makes research on novel therapeutic agents necessary. Targeting of Schistosoma mansoni epigenetic enzymes, which regulate the parasitic life cycle, emerged as promising approach. Due to the strong effects of human Sirtuin inhibitors on parasite survival and reproduction, Schistosoma sirtuins were postulated as therapeutic targets. In vitro testing of synthetic substrates of S. mansoni Sirtuin 2 (SmSirt2) and kinetic experiments on a myristoylated peptide demonstrated lysine long chain deacylation as an intrinsic SmSirt2 activity for the first time. Focused in vitro screening of the GSK Kinetobox library and structure-activity relationships (SAR) of identified hits, led to the first SmSirt2 inhibitors with activity in the low micromolar range. Several SmSirt2 inhibitors showed potency against both larval schistosomes (viability) and adult worms (pairing, egg laying) in culture without general toxicity to human cancer cells.<br>

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