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61.
Nucleoli were studied in lymphoblasts of children (untreated with cytostatic therapy) suffering from acute lymphoblastic leukemias (ALL) by means of a simple cytochemical procedure for the demonstration of RNA to provide information on the incidence of the main nucleolar types and the number of nucleoli in these cells. The values of the nucleolar coefficient reflecting the number of nucleoli per lymphoblast ranged between 1.66 and 2.03. The slightly larger values of the nucleolar coefficient in T-ALL were not statistically significant in comparison with those in nonT-ALL. Lymphoblasts in the bone marrow as well as the peripheral blood of both nonT and T-ALL patients mostly contained, “active” (RNA transcribing) large nucleoli with a relatively uniform distribution of RNA. “Inactive” micronucleoli or particularly “resting” ring shaped nucleoli were noted less frequently in these cells. On the other hand, the larger percentage of lymphoblasts determined in specimens stained with the panoptic staining (May-Grünwald-Giemsa) in comparison with that of lymphoblasts with “active nucleoli” in specimens stained for RNA apparently indicates the absence of such nucleoli in some of these cells. These cells might represent ageing, not proliferating, cells the existence of which has been already suggested by previous studies based on a different methodical approach. 相似文献
62.
63.
Plasticity of representational maps in adult cerebral cortex has been
documented in both sensory and motor cortex, but the anatomical basis for
cortical plasticity remains poorly understood. To investigate horizontal
connectivity in primary motor cortex (M1) as a putative anatomical
substrate for short-term, functional plasticity of adult motor cortical
representations, a combination of electrical stimulation and biocytin
labeling was used to examine pre-existing patterns of intrinsic connections
in adult rat M1 in relationship to the pattern of reorganization of the
motor movement may induced by transection of the contralateral facial
nerve. Two hours after nerve cut, small, circumscribed regions of the
forelimb representation expanded medially into territory previously devoted
to the vibrissae representation. Outside of this novel, expanded forelimb
region, no forelimb movement could be evoked from the former vibrissae
representation at any time over the period of hours tested, thus
representing silent cortex. Injections placed into vibrissae cortex
representing the newly expanded forelimb representation gave rise to
labeled axons and dense terminal fiber labeling which crossed the
forelimb/vibrissae border and extended up to 1.2 mm within the
low-threshold forelimb representation. In contrast, injections placed into
silent vibrissae cortex gave rise to labeled axons and terminal boutons
which remained mostly restricted to the original vibrissae representation,
with only sparse projections that crossed into the low-threshold forelimb
representation. Thus, these results suggest that the extent of short-term,
functional reorganization of M1 induced within the first several hours
following peripheral nerve cut is mediated, and constrained, by an
anatomical framework of pre-existing, horizontal projections which traverse
representation borders.
相似文献
64.
65.
66.
A Mitro Z Daxnerova K Smetana A Marossy P Jalc J Marsala 《Journal für Hirnforschung》1983,24(3):273-280
The partial ischemia of the adult dogs, both males and females was induced by the ligature of aorta abdominalis above the branching of arteria coeliaca within 80 minutes and 120 minutes duration with the following preparation of L6 und L7 dorsal root ganglia. The nuclei and nucleoli of the dorsal root ganglia nerve cells were studied by the usual standard transmission electron microscopic procedures. Comparing the control and ischemized material we have observed the different reaction of the nuclei and nucleoli to the ischemia. Some of these structures remained unchanged, the others demonstrated a various degree of the alteration. After the partial ischemia some nucleoli were more compact, some nucleolonemata were less distinct but no karyoplasmic changes were noted. The nucleolar interstitial vacuoles were occasionally enlarged and the satellite bodies were observed scarcely in the proximity of the nucleolus. 相似文献
67.
68.
69.
70.
Zbyněk Likovský Jaroslava Grimová Antonín Dlabač Jan Hondlík Karel Smetana 《Naunyn-Schmiedeberg's archives of pharmacology》1973,276(2):181-186
Summary The incidence of diverse types of nucleoli in peripheral blood lymphocytes was established in albino rats with adjuvant-induced disease, either untreated or receiving trimethazone, phenylbutazone, indometacin, or 6-mercaptopurine. Apart from typical clinical symptoms, the adjuvant-induced disease was characterized by an increase in the number of active nucleoli in the lymphocytes present in the peripheral blood of the diseased animals. This increase was influenced by the administration of any of the drugs enumerated. 相似文献