From:
Sukie Crandall
Date: 2010-04-18 02:57:05 UTC
Subject: [ferrethealth] abstracts
To: fhl <ferrethealth@yahoogroups.com>
This article was last year but seems to have just reached PubMed
http://www.ncbi.nlm.nih.gov/pubmed/20396607
> J Mater Res. 2009 Mar;24(3):638-646.
> Nanoindentation of histological specimens: Mapping the elastic
> properties of soft tissues.
> Akhtar R, Schwarzer N, Sherratt MJ, Watson RE, Graham HK, Trafford
> AW, Mummery PM, Derby B.
> School of Materials, University of Manchester, Manchester M1 7HS,
> United Kingdom.
> Abstract
> Although alterations in the gross mechanical properties of dynamic
> and compliant tissues have a major impact on human health and
> morbidity, there are no well-established techniques to characterize
> the micromechanical properties of tissues such as blood vessels and
> lungs. We have used nanoindentation to spatially map the
> micromechanical properties of 5-mum-thick sections of ferret aorta
> and vena cava and to relate these mechanical properties to the
> histological distribution of fluorescent elastic fibers. To decouple
> the effect of the glass substrate on our analysis of the
> nanoindentation data, we have used the extended Oliver and Pharr
> method. The elastic modulus of the aorta decreased progressively
> from 35 MPa in the adventitial (outermost) layer to 8 MPa at the
> intimal (innermost) layer. In contrast, the vena cava was relatively
> stiff, with an elastic modulus >30 MPa in both the extracellular
> matrix-rich adventitial and intimal regions of the vessel. The
> central, highly cellularized, medial layer of the vena cava,
> however, had an invariant elastic modulus of ~20 MPa. In
> extracellular matrix-rich regions of the tissue, the elastic
> modulus, as determined by nanoindentation, was inversely correlated
> with elastic fiber density. Thus, we show it is possible to
> distinguish and spatially resolve differences in the micromechanical
> properties of large arteries and veins, which are related to the
> tissue microstructure.
> PMID: 20396607
A cousin:
http://www.ncbi.nlm.nih.gov/pubmed/20394608
> Biol Rev Camb Philos Soc. 2010 Apr 14. [Epub ahead of print]
> The concept of superfetation: a critical review on a 'myth' in
> mammalian reproduction.
> Roellig K, Menzies BR, Hildebrandt TB, Goeritz F.
> Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str.
> 17, 10315 Berlin, Germany.
> Abstract
> Superfetation is understood as another conception during an already
> ongoing pregnancy. This implies the existence of young of different
> developmental stages within the female reproductive tract during
> certain periods of pregnancy. Nevertheless, a clear definition of
> the term as well as distinct criteria to identify the occurrence of
> superfetation in a species is missing. The variable anatomy of
> mammalian reproductive tracts seems to make the occurrence of
> superfetation more or less likely but impedes the simple evaluation
> of whether it is present or not. Additionally, adequate
> determination methods are missing or are difficult to apply at the
> right time. Superfetation or rather superfetation-like pregnancies
> are reported for numerous species including humans, livestock and
> rodents. The usual criteria to assume a case of superfetation
> include the finding of discordantly developed young within the
> uterus during post mortem or parturition of young after a birth
> interval shorter than the assumed pregnancy length. Often the
> occurrence of superfetation is concluded because other explanations
> of reproductive artifacts are missing. Even severe reproductive
> pathologies are often confused with superfetation. True
> superfetation or superfetation as a reproductive strategy may exist
> in some mammals. In the American mink (Neovison (Mustela) vison) and
> the European badger (Meles meles) superfetation occurs in
> combination with embryonic diapause. In the European brown hare
> (Lepus europaeus), superfetation has long been assumed to exist but
> evidence is still controversial. Superfetation definitely occurs in
> certain species of poeciliid and zenarchopterid fish, some of which
> also exhibit viviparity and maternal care. In mammals, the evolution
> of such a reproductive mechanism poses many interesting
> evolutionary, endocrine, microbial and immunological questions that
> require further investigation. Here we review the scant and at times
> ancient literature on this poorly understood topic. The different
> manifestations of superfetation are defined and reliable criteria to
> detect superfetation are outlined. Also, the differentiation of
> superfetation into a reproductive strategy or as a disrupted,
> abnormal reproductive function is discussed. Due to the different
> discussed functional aspects of superfetation, it is appropriate to
> establish a more detailed scheme to classify the true natural
> superfetation cases into superfertilization, superconception and
> superfetation proper. To date, there is no mammal species known for
> which superfetation proper in terms of finding discordantly
> developed fetuses has been conclusively demonstrated to be not only
> a rare occurence but an evolved reproductive strategy.
> PMID: 20394608
Sukie (not a vet)
Recommended ferret health links:
http://pets.groups.yahoo.com/group/ferrethealth/
http://ferrethealth.org/archive/
http://www.afip.org/ferrets/index.html
http://www.miamiferret.org/
http://www.ferrethealth.msu.edu/
http://www.ferretcongress.org/
http://www.trifl.org/index.shtml
http://homepage.mac.com/sukie/sukiesferretlinks.html
all ferret topics:
http://listserv.ferretmailinglist.org/archives/ferret-search.html
"All hail the procrastinators for they shall rule the world tomorrow."
(2010, Steve Crandall)
------------------------------------
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/ferrethealth/
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/ferrethealth/join
(Yahoo! ID required)
<*> To change settings via email:
ferrethealth-digest@yahoogroups.com
ferrethealth-fullfeatured@yahoogroups.com
<*> To unsubscribe from this group, send an email to:
ferrethealth-unsubscribe@yahoogroups.com
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/