1,721,130 research outputs found
Motonuclear changes after cranial nerve injury and regeneration
No full textLittle is known about the mechanisms at play in nerve regeneration after nerve injury. Personal studies are reported regarding motonuclear changes after regeneration of injured cranial nerves, in particular of the facial and oculomotor nerves, as well as the influence that the natural molecule acetyl- L-carnitine (ALC) has on post-axotomy cranial nerve motoneuron degeneration after facial and vagus nerve lesions. Adult and newborn animal models were used. Massive motoneuron response after nerve section and reconstruction was observed in the motonuclei of all nerves studied. ALC showed to have significant neuroprotective effects on the degeneration of axotomized motoneurons. Complex quantitative, morphological and somatotopic nuclear changes occurred that sustain new hypotheses regarding the capacities of motoneurons to regenerate and the possibilities of new neuron proliferation. The particularities of such observations are described and discussed
Telomerase expression in intracranial tumors: prognostic potential for malignant gliomas and meningiomas
No full textEffects of levo-acetylcarnitine on second motoneuron survival after axotomy
No full textLittle is known about factors that regulate the survival of cranial motoneurons which project to peripheral targets. Various neurotrophic factors of central and peripheral origin have been isolated. In this study, we examined thirteen newborn Wistar rats to determine the effects of acetyl-L- carnitine treatment on the survival of motoneurons within the facial nucleus after transection of the facial nerve. Acetyl-L-carnitine was administered for 7 days in seven rats after nerve transection, while saline solution was injected in 6 rats used as controls. Both the motoneuron number and the motoneuron diameter were significantly higher in the facial nucleus of the rats treated with acetyl-L-carnitine than in the facial nucleus of the control rats. The results obtained suggest that acetyl-L-carnitine can rescue a substantial number of facial motoneurons from axotomy-induced cell death. Compared to neurotrophic factors, because of its simple molecular structure, acetyl-L-carnitine permits a sate oral and parenteral administration. It is suggested that acetyl-L-carnitine could be considered for use as a therapeutic agent in neurodegenerative disorders
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
HUMAN PLACENTAL BETA-ENDORPHIN (HP-BETA-EP)
No full textThe previous finding that the placenta is capable of synthesising an
ACTH-like peptide, human chorionic corticotrophin (hCC)(l) and the observate
that both ACTH andP. EP are part of the same glycoprotein of 31K daltons in t~
p i tui tary (2) led us to investigate the presence of" EP in placental e x t r ac cs
Freshly collected, sliced ~nd cold saline Ivashed placenta was extractei
with acid acetone (l) to obtain a placental powder (PP)(5.8mg PP/g placenta'
protein content 460ug/mg) which was then tested EorfiEP in a radioreceptor
assay (RRA). For this assay 3H-D-ala-enkephalin was used a s t r a c e r and)lEP i.
Tris-HCl 50mM pH 7.4+Bacitracin 50ug/ml as standard. Membranes were obtaip.=~
by homogenisation of rat forebrains in 25 volumes of Tris-HCl (Polytron set =
for 15sec) a nd c e n t-r i f ug a t i o n at 15,000rpm x 15min (JA 20 ro t o r ) . The memb:--
anes were diluted with 5ml MnC12 60mM (frozen), 125ul Bacitracln stock solu:-
ion and 24.875ml 50Mrn Tris-HCl pH 7.4 buffer. Fo r the assay, 500).11. membrane
suspension, 100ul tracer, 100).1m standard or unknown sample and buffer up to ::.
mi were used. After 2hr incubation and shaking at 26°C, filtration was per:-
ormed on Millipore with cold buffer washing solution. PP prepared as above
gave a dilution curve p a r a l I e I to that oEPEP and a potency o f 5.15ngpEP/mb
PP protein. These re~ult$ re~ain qp~n çq criticis~ due to the lack of spec-
ificity of the RRA
Regeneration of trasected cortico-spinal tract axons is promoted by the combined application of recombinant vascular endothelial growth factor (VEGF) and adenovirus coding for VEGF
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