Luseægs vehæftning til hår
SpørgsmålJeg søger oplysninger om menneskelus.
Jeg søger videnskabelige dokumentation for hvilken mekanisme(r) der gør at luseæg er i stand til at hæfte til menneskehår.
SvarDer findes ikke mange artikler i verdenslitteraturen, der behandler dette emne, et par af de mest centrale er:
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Journal of Parasitology Volume 85, Issue 3, June 1999, Pages 559-561
Molecular composition of the louse sheath
Burkhart, C.N.a , Stankiewicz, B.A.a b , Pchalek, I.a c , Kruge, M.A.a d , Burkhart, C.G.a e
a Department of Biology, University of Toledo, Toledo, OH 43606, United States
b Shell E and P Technology Company, 3737 Bellaire Blvd., Houston, TX 77025, United States
c Department of Chemistry, Lourdes College, Sylvania, OH 43560, United States
d Department of Geology, Southern Illinois University, Carbondale, IL 62901-4324, United States
e Department of Medicine, Medical College of Ohio, 5600 Monroe Street, Sylvania, OH 43560, United States
Abstract
Flash pyrolysis-gas chromatography/mass spectrometry was used to assess the chemical composition of the head louse's nit sheath. The pyrolyzate of the female insect's secretions, which form a cement-like cylinder holding the egg onto the hair, is dominated by amino acid derivatives and fatty acids. No chitin-specific compounds were detected in the sheath. These results, contrary to previous reports, show that the polymeric complex of the sheath is composed of protein-acceous moieties, possibly cross-linked to aliphatic components. This study constitutes the first chemical characterization of the pyrolysis products o insect (louse) glue and unequivocally confirms that louse sheaths are not chitinous, as suggested by earlier histochemical studies. Development of agents that might loosen nits from the hair shaft is dependent on research that addresses the chemical composition of the nit sheath.
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Journal of the American Academy of Dermatology Volume 53, Issue 1, July 2005, Pages 129-133
Head lice: Scientific assessment of the nit sheath with clinical ramifications and therapeutic options
Burkhart, C.N.a c , Burkhart, C.G.b
a University of North Carolina at Chapel Hill
b Division of Dermatology, Medical College of Ohio
c Division of Dermatology, Medical College of Ohio, 5600 Monroe St, Sylvania, OH 43560, United States
Abstract
Head lice, like many insects, produce a protective coating for their newly laid eggs that is essential to the survival of the species. Knowledge of the composition of the sheath, which is the glue by which the egg is attached to human hair, and the nit laying process could lead to production of agents that could be used to attack louse infestations by interfering with the normally protected environment of nymph development within the egg. The physical removal of nits has become an important part of treatment of head louse infestations given the "no-nit" policy in schools. Biochemical analysis has revealed that the nit sheath of the head louse is composed of 4 bands of protein, possibly cross-linked to aliphatic components with a tertiary structure of ß sheeting. Nature has protected the louse by making the nit sheath similar in composition to the hair; thereby, agents designed to unravel the nit sheath may also damage human hair. Possible targets to destroy the nit sheath include proteases, denaturants, ß sheet breaker proteins, and small protein inhibitors of sheath formation. Better understanding of insect glues may allow us to develop compounds so that the liquid secretions of the collateral glands of the female louse, which becomes the nit sheath, do not solidify by oxidation when placed with the louse egg onto human hair. Knowledge of insect behavior, such as oviposition, may also suggest methods for repelling female lice from laying eggs onto hair. Alternatively, agents that coat the nits and restrict the oxygen transfer to the developing larvae may prove beneficial. © 2005 by the American Academy of Dermatology, Inc.
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Hvis du selv vil søge videre, kan jeg anbefale de to firt tilgængelige baser:
PubMed (http://pubmed.gov) og Google Scholar (http://scholar.google.com)
I begge baser kan du søge på ord som:
Head lice
Head louse
Pediculus capitis
Pediculus humanus
Peduculus humanus capitis
+ ord for æg: nit, nits, egg
I PubMed kan du kombinere ord med "AND", "OR" og "NO" skrevet med store bogstaver, f.eks. head AND (lice OR louse) AND (nit OR nits OR egg OR eggs), i Google Scholar skal du vælge "Avanceret søgning" og her udfylde søgefelterne: skal / kan optræde osv.
PubMed's artikler er indekseret på en sådan måde, at du kan finde alle "Related articles" gennem linkene i højre side, Google Scholar søger i hele artiklens tekst og giver dig mulighed for at finde andre artikler, der citerer en given artikel.
I begge tilfælde vil du finde nogle artikler, som er frit tilgængelige på nettet, hvor der kræves betaling, kan du bestille en gratis kopi gennem http://bibliotek.dk - søg kun på tidsskriftets navn - til levering gennem dit lokale bibliotek, eller du kan få adgang til artiklerne på eet at de store forskningsbiblioteker i Københavnsomårdet
12-11-2012
NB! Eksterne link i denne besvarelse fungerede da svaret blev afsendt. De er ikke blevet kontrolleret siden og kan være blevet inaktive