Macrofibrils, the main structural features within the cortical cells of mammalian hair shafts, are long composite bundles of keratin intermediate filaments (KIFs) embedded in a matrix of keratin-associated proteins. The KIFs can be helically arranged around the macrofibril central axis, making a cylinder within which KIF helical angle relative to macrofibril axis increases approximately linearly from macrofibril centre to edge. Mesophase-based self-assembly has been implicated in the early formation of macrofibrils, which first appear as liquid-crystal tactoids in the bulb of hair follicles. Formation appears to be driven initially by interactions between pre-keratinized KIFs. Differences in the nature of these KIF-KIF interactions could result in all macrofibrils being internally twisted in a single handedness, or a 50:50 mixture of handedness within each cortical cell. We data-mined 41 electron tomograms containing three-dimensional macrofibril data from previously published studies of hair and wool. In all 644 macrofibrils examined we found that within each tomogram all macrofibrils had the same handedness. We concluded that earlier reports of left- and right-handed macrofibrils were due to artefacts of imaging or data processing. A handedness marker was used to confirm (using re-imaged sections from earlier studies) that, in both human and sheep, all macrofibrils are left-handed around the macrofibril axis. We conclude that this state is universal within mammalian hair. This also supports the conclusion that the origin of macrofibril twist is the expression of chiral twisting forces between adjacent KIFs, rather than mesophase splay and bending forces relaxing to twisting forces acting within a confined space.
- MeSH
- cytoskelet chemie ultrastruktura MeSH
- intermediární filamenta chemie ultrastruktura MeSH
- keratiny chemie ultrastruktura MeSH
- lidé MeSH
- ovce genetika MeSH
- tomografie elektronová MeSH
- vlasy, chlupy chemie ultrastruktura MeSH
- vlna chemie ultrastruktura MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Contemporary science thrives on collaborative networks, but these can also be found elsewhere in the history of science in unexpected places. When Mendel turned his attention to inheritance in peas he was not an isolated monk, but rather the latest in a line of Moravian researchers and agriculturalists who had been thinking about inheritance for half a century. Many of the principles of inheritance had already been sketched out by Imre Festetics, a Hungarian sheep breeder active in Brno. Festetics, however, was ultimately hindered by the complex nature of his study traits, aspects of wool quality that we now know to be polygenic. Whether or not Mendel was aware of Festetics’s ideas,both men were products of the same vibrant milieu in 19th-century Moravia that combined theory and agricultural practice to eventually uncover the rules of inheritance.
- MeSH
- chov dějiny MeSH
- dědičnost MeSH
- dějiny 18. století MeSH
- dějiny 19. století MeSH
- genetika dějiny MeSH
- hrách setý genetika MeSH
- lidé MeSH
- modely genetické MeSH
- ovce genetika MeSH
- vlna chemie dějiny MeSH
- zvířata MeSH
- Check Tag
- dějiny 18. století MeSH
- dějiny 19. století MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- historické články MeSH
- Geografické názvy
- Česká republika MeSH
- Maďarsko MeSH
The objective of this paper was to adapt gene-flow methodology for the calculation of economic weights (EW) for direct and maternal traits and trait components in sheep and to apply this methodology to the Suffolk breed in the Czech Republic. Computer programs were developed in which annual-lambing sheep production systems with purebreeding or partial terminal crossing were simulated. Using these programs, the EW for 12 production and functional traits were estimated for i) Suffolk sires whose sons were used both in purebreeding and in terminal crossing with the 4 dual-purpose breeds, Romanov, Sumavska, Romney, and Merinolandschaf; and ii) Suffolk sires used only for terminal crossing. For case (i), the EW were at first calculated separately for the purebreeding system and for the crossing systems with the 4 dual-purpose breeds in dam position. Compound EW for the general breeding goal for Suffolk were then estimated as weighted averages from the EW in the 5 subsystems. Standardized EW were calculated by multiplying the marginal EW with the genetic SD of the trait, and relative EW were defined as absolute values of the standardized EW expressed as percentage of the sum of the absolute values of the standardized EW over all traits. The 5 most important trait components for Suffolk sires whose sons were used both in purebreeding and in terminal crossing were (relative EW given in parentheses): the direct components of survival rate until weaning (21.0%), daily BW gain until weaning (14.1%), survival rate at birth (14.0%), the maternal component of survival rate until weaning (10.7%), and litter size at lambing (7.6%). There were only small differences between the relative EW calculated for the whole system with pure- and crossbreeding and the relative EW for the purebred system within the Suffolk breed. Therefore, selection of Suffolk rams using a selection index based on the compound EW is expected to be of high efficiency in all of the simulated breeding systems. Only direct traits were relevant for Suffolk sires used only for terminal crossing; the most important (range of relative EW calculated for the 4 crossing systems given in parentheses) were survival rate until weaning (35.2 to 36.5%), daily BW gain until weaning (24.2 to 26.3%), and survival rate at birth (23.7 to 24.8%).
- MeSH
- biologické modely MeSH
- chov ekonomika MeSH
- genetická variace MeSH
- hmotnostní přírůstek MeSH
- ovce genetika MeSH
- rozmnožování genetika fyziologie MeSH
- tok genů MeSH
- vlna MeSH
- zemědělství ekonomika MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
OBJECTIVES: The aim of the study was to determine the frequency of contact sensitization in patients with lower extremity dermatitis. METHODS: Between the years 2001 and 2007, the authors investigated 462 patients (mean age 49.1 years, 196 men and 266 women) with the eczema/dermatitis localized on their lower extremities, including feet. The patients were investigated with epicutaneous tests of the European Standard Series and also with other special patch tests. RESULTS: The most frequent allergens were balsam of Peru, 44/462 (9.5%); wool alcohols, 41/462 (8.9%); nickel sulphate, 39/462 (8.4%); propolis, 35/462 (7.6%); fragrance mix, 34 (7.4%) and colophony, 29/462 (6.3%). CONCLUSIONS: In patients with lower extremity dermatitis the frequency of contact sensitization is still high, and therefore investigation with epicutaneous tests should belong to the routine dermatological diagnostic procedure in these patients.
- MeSH
- balzámy škodlivé účinky MeSH
- bérec MeSH
- ekzém diagnóza epidemiologie MeSH
- kontaktní dermatitida diagnóza epidemiologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- náplasťové testy MeSH
- nikl škodlivé účinky MeSH
- parfém škodlivé účinky MeSH
- propolis škodlivé účinky MeSH
- rostlinné pryskyřice škodlivé účinky MeSH
- vlna škodlivé účinky MeSH
- zvířata MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Cell-mediated cytotoxicity of adherent and non-adherent subpopulations of mouse lymph node cells sensitized in vitro on monolayers of syngeneic, methylcholanthrene-induced sarcoma cells was examined by inhibition of 3H-thymidine incorporation. The cell-mediated cytotoxicity of nylon wood-adherent, non-adherent and unfractionated lymph node cells was found to be equally efficient.
- MeSH
- aktivace lymfocytů účinky léků MeSH
- antigeny nádorové imunologie MeSH
- buněčná adheze * MeSH
- cytotoxické testy imunologické * MeSH
- experimentální sarkom chemicky indukované imunologie MeSH
- fytohemaglutininy farmakologie MeSH
- imunizace * MeSH
- imunoglobuliny analýza MeSH
- lymfocyty imunologie MeSH
- methylcholanthren MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- nylony MeSH
- techniky in vitro MeSH
- transplantace nádorů MeSH
- vlna MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
