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1.
G. Modiano G. Cermele C. Santolamazza S. Biagioni G. Scarsella L. E. Pacifici G. Toschi 《International Journal of Anthropology》1987,2(1):61-73
392 random patients treated with SCC prior to surgery were assayed for pseudocholinesterase activity and electrophoretic pattern.
The estimate of the percent frequencies of theE
1
a
allele were 1.16±0.38 and of the C5 (+) phenotype 9.7±1.5, both typical of Caucasian populations. By combining the presentE
1
a
gene frequency estimate with that from another sample of the same population (Cermele
et al., 1987) a better estimate with smaller confidence limits was obtained, that is: 1,14±0,27. One subject interpreted asE
1
a
E
1
a
on phenotypic grounds was also found (expected 0,05) in this random sample.
A correlation coefficient of −0.521 was found between E activity and myorelaxation time in the whole sample. High correlation
values (r=−0.55 and r=−0.46) were found forE
1
u
E
1
u
; C5 (−) andE
1
u
E
1
u
; C5 (+) individuals, respectively, showing a strong dependence of the latter variable on the former one even within apparently
homogeneous classes. The use of the product of these two variables as a classification criterion allowed the identification
of a subject with very long myorelaxation time but normal activity. 相似文献
2.
Expression of adult fast pattern of acetylcholinesterase molecular forms by mouse satellite cells in culture 总被引:1,自引:0,他引:1
M. Immacolata Senni Francesco Castrignanò Giancarlo Poiana Giulio Cossu Gianfranco Scarsella Stefano Biagioni 《Differentiation; research in biological diversity》1987,36(3):194-198
The pattern of acetylcholinesterase (AChE) molecular forms, obtained by sucrose gradient sedimentation, was studied at different in vitro developmental stages of myogenic cells isolated from adult mouse skeletal muscle. Only the globular forms were present in rapidly dividing satellite cells during the first days in culture. After myotube formation, a pattern similar to that described in mammalian fast-twitch skeletal muscle was observed. This pattern did not change during the following period in culture (up to 1 month) nor could it be modified by co-culturing with spinal cord motoneurons or by addition of brain-derived extracts. The internal-external localization of AChE molecular forms has been determined by the use of echothiophate iodide, a membrane-impermeant irreversible inhibitor of AChE. Echothiophate-treated cultures showed about 40% of both asymmetric and globular forms localized on the sarcolemma, with their active sites oriented outward. Analysis of culture medium from untreated cultures revealed the presence of both asymmetric and globular forms. When the same analysis was repeated on cultures of myoblasts derived from 16-day-old mouse embryos, the pattern of AChE forms was different. The myotubes derived from these cells exhibit a very small proportion of asymmetric form, which was not released into the medium. This pattern was not further modified during the following days of culture, nor by co-cultures with spinal cord motoneurons or by incubations with brain-derived extracts. Thus, the myotubes derived from myoblasts express in culture a clear phenotypic difference when compared to the corresponding myotubes from satellite cells, supporting the view that these two myogenic cells are endowed with different developmental programs. 相似文献
3.
4.
Direct sequencing of the mitochondrial displacement loop (D-loop) of shrews
(genus Sorex) for the region between the tRNA(Pro) and the conserved
sequence block-F revealed variable numbers of 79-bp tandem repeats. These
repeats were found in all 19 individuals sequenced, representing three
subspecies and one closely related species of the masked shrew group (Sorex
cinereus cinereus, S. c. miscix, S. c. acadicus, and S. haydeni) and an
outgroup, the pygmy shrew (S. hoyi). Each specimen also possessed an
adjacent 76-bp imperfect copy of the tandem repeats. One individual was
heteroplasmic for length variants consisting of five and seven copies of
the 79-bp tandem repeat. The sequence of the repeats is conducive to the
formation of secondary structure. A termination-associated sequence is
present in each of the repeats and in a unique sequence region 5' to the
tandem array as well. Mean genetic distance between the masked shrew taxa
and the pygmy shrew was calculated separately for the unique sequence
region, one of the tandem repeats, the imperfect repeat, and these three
regions combined. The unique sequence region evolved more rapidly than the
tandem repeats or the imperfect repeat. The small genetic distance between
pairs of tandem repeats within an individual is consistent with a model of
concerted evolution. Repeats are apparently duplicated and lost at a high
rate, which tends to homogenize the tandem array. The rate of D- loop
sequence divergence between the masked and pygmy shrews is estimated to be
15%-20%/Myr, the highest rate observed in D-loops of mammals. Rapid
sequence evolution in shrews may be due either to their high metabolic rate
and short generation time or to the presence of variable numbers of tandem
repeats.
相似文献
5.
6.
大鼠胼胝体内神经肽Y免疫反应阳性纤维的发育 总被引:1,自引:0,他引:1
本实验用免疫组织化学ABC法研究了大鼠胼胝体内神经肽Y免疫反应阳性(NPY-IR)纤维的生后发育。结果发现,许多NPY-IR纤维在大鼠出生时便存在于胼胝体内。NPY-IR胼胝体纤维的密度在生后1周内继续逐渐增高,在第2周内达到最高峰。之后,NPY-IR胼胝体纤维的密度逐渐下降,至第3周末时接近成年时的水平,即仅有少量NPY-IR纤维存在于胼胝体内。这些结果提示在大鼠早期生后发育过程中许多NPY-IR胼胝体纤维是暂时性的,其作用可能与大脑皮质的机能发育有关。 相似文献
7.
8.
Black AP Bhayani H Ryder CA Pugh MT Gardner-Medwin JM Southwood TR 《Arthritis research & therapy》2003,5(5):R277-R284
The aim of this research was to determine whether all memory T cells have the same propensity to migrate to the joint in patients
with juvenile idiopathic arthritis. Paired synovial fluid and peripheral blood mononuclear cell proliferative responses to
a panel of antigens were measured and the results correlated with a detailed set of laboratory and clinical data from 39 patients
with juvenile idiopathic arthritis. Two distinct patterns of proliferative response were found in the majority of patients:
a diverse pattern, in which synovial fluid responses were greater than peripheral blood responses for all antigens tested;
and a restricted pattern, in which peripheral blood responses to some antigens were more vigorous than those in the synovial
fluid compartment. The diverse pattern was generally found in patients with a high acute phase response, whereas patients
without elevated acute phase proteins were more likely to demonstrate a restricted pattern. We propose that an association
between the synovial fluid T cell repertoire and the acute phase response suggests that proinflammatory cytokines may influence
recruitment of memory T cells to an inflammatory site, independent of their antigen specificity. Additionally, increased responses
to enteric bacteria and the presence of αEβ7 T cells in synovial fluid may reflect accumulation of gut associated T cells
in the synovial compartment, even in the absence of an elevated acute phase response. This is the first report of an association
between the acute phase response and the T cell population recruited to an inflammatory site. 相似文献
9.
Hollenbach S Thampi P Viswanathan T Abraham EC 《Molecular and cellular biochemistry》2003,250(1-2):73-80
We investigated early alterations in rat neurons after experimental ischemic stress. Transient ischemia was generated by bilateral occlusion of the carotids after hypoxia. Data show a relevant increase of the nuclear level of ubiquitin 2 h post-stress as evaluated by immuno-cytolocalization. Ubiquitin returns to normal levels after 6 h. The increase in ischemic/hypoxic rats was localized preferentially in nuclei of hippocampal neurons, although some augmentation was also shown essentially in dendrites. The activation of ubiquitin system is related to a defective homeostasis and might trigger different degenerative processes. With respect to this, we observed chromatin alterations by densitometric analysis. The shown extensive DNA degeneration is consistent with the occurrence of necrotic phenomena at an early stage. However the parallel internucleosomal specific DNA fragmentation, strongly suggests that apoptotic events also occur. In any case both necrosis and apoptosis are likely to occur at same time, although apoptosis is less extensive, and two phenomena take place in different neural cells. 相似文献
10.
Rates and patterns of evolution in partial sequences of five mitochondrial
genes (cytochrome b, ATPase 6, NADH dehydrogenase subunit 5, tRNA(Glu), and
the control region) were compared among taxa in the passerine bird genera
Fringilla and Carduelis. Rates of divergence do not vary significantly
among genes, even in comparisons with the control region. Rate variation
among lineages is significant only for the control region and NADH
dehydrogenase subunit 5, and patterns of variation are consistent with the
expectations of neutral theory. Base composition is biased in all genes but
is stationary among lineages, and there is evidence for directional
mutation pressure only in the control region. Despite these similarities,
patterns of substitution differ among genes, consistent with alternative
regimes of selective constraint. Rates of nonsynonymous substitution are
higher in NADH dehydrogenase subunit 5 than in other protein-coding genes,
and transitions exist in elevated proportions relative to transversions.
Transitions appear to accumulate linearly with time in tRNA(Glu), and
despite exhibiting the highest overall rate of divergence among species,
there are no transversional changes in this gene. Finally, for resolving
phylogenetic relationships among Fringilla taxa, the combined
protein-coding data are broadly similar to those of the control region in
terms of phylogenetic informativeness and statistical support.
相似文献