16 research outputs found
Nanotools for Neuroscience and Brain Activity Mapping
Neuroscience is at a crossroads. Great effort is being invested into deciphering specific neural interactions and circuits. At the same time, there exist few general theories or principles that explain brain function. We attribute this disparity, in part, to limitations in current methodologies. Traditional neurophysiological approaches record the activities of one neuron or a few neurons at a time. Neurochemical approaches focus on single neurotransmitters. Yet, there is an increasing realization that neural circuits operate at emergent levels, where the interactions between hundreds or thousands of neurons, utilizing multiple chemical transmitters, generate functional states. Brains function at the nanoscale, so tools to study brains must ultimately operate at this scale, as well. Nanoscience and nanotechnology are poised to provide a rich toolkit of novel methods to explore brain function by enabling simultaneous measurement and manipulation of activity of thousands or even millions of neurons. We and others refer to this goal as the Brain Activity Mapping Project. In this Nano Focus, we discuss how recent developments in nanoscale analysis tools and in the design and synthesis of nanomaterials have generated optical, electrical, and chemical methods that can readily be adapted for use in neuroscience. These approaches represent exciting areas of technical development and research. Moreover, unique opportunities exist for nanoscientists, nanotechnologists, and other physical scientists and engineers to contribute to tackling the challenging problems involved in understanding the fundamentals of brain function
Immunodetection and clinico-pathological correlates of two tumour growth regulators in laryngeal carcinoma
Activation of telomerase, present in the vast
majority of all human cancers, is associated with
elongation of chromosomal telomeres and consequent
cell immortalization. Telomere length homeostasis is a
dynamic process governed by the negative feedback
mechanism of the telomeric repeat binding factor 1
(TRF1) which inhibits the action of telomerase in
telomerase-positive cells. In an attempt to investigate
markers of tumour growth as possible prognostic
indicators in laryngeal cancer, we studied the expression
of TRF1 and of the proliferation marker Ki67 on 96
invasive squamous carcinomas of the larynx. A standard
three step immunoperoxidase staining method was
applied on paraffin sections incubated with appropriate
polyclonal antibodies. The percentages of Ki67- and
TRF1-immunopositive cancerous cells were calculated
by image analysis. Univariate and multivariate statistical
analysis of the staining results were performed in order
to detect any association of the examined
immunomarkers with the tumours’ classical
clinicopathological variables including nuclear
morphometric features as well as with patients’ diseasefree
survival. Ki67 immunostaining was positively
linked with advanced patients’ age, nodal involvement
as well as presence of early recurrence. No relation was
found between proliferative fraction and TRF1
immunoexpression. TRF1 was expressed in 55.2% of all
cases and was positively linked only to tumour size.
Multivariate statistical analysis revealed the presence of
lymph nodal metastasis and Ki67 immunopositivity
index ³ 20% as significant predictors of relapse.
Increased Ki67 immunostaining appears to be a
promising marker of tumour aggressiveness in laryngeal
c a n c e r. After one point at the tumour’s natural history,
the maintenance of tumour growth does not seem to
depend on cell proliferation but on TRF1
immunoexpression. Whether the latter can be used for
the identification of immortalized cells in every-day practice is worth investigating