1,117 research outputs found
Molecular Pathogenesis of Pheochromocytomas and Paragangliomash
General aspectsParaganglia are small neuroendocrine organs, that usually manifest as anatomically discrete
bodies, the parenchymal cells of which are neural crest-derived, and produce catecholamines
and various peptides. One group of paraganglia is aligned to the sympathoadrenal and the other
to the parasympathetic autonomic nervous system.1,2 Sympathetic paraganglia are distributed
along the pre- and paravertebral sympathetic chains and follow the sympathetic innervations of the
pelvic and retroperitoneal organs. Their exact locations are somewhat variable, with the exception
of the adrenal medulla and the organs of Zuckerkandl. Parasympathetic paraganglia are almost
exclusively located in the region of the cranial and thoracic branches of the glossopharyngeal
and vagal nerves. The principal glossopharyngeal paraganglia are the tympanic paraganglia,
situated in the wall of the middle ear, and the carotid bodies (Figure 1).
Neoplasms of the neuroendocrine cells found within the sympathetic or parasympathetic
paraganglionic axes are designated pheochromocytoma and paraganglioma. The name
pheochromocytoma – the Greek synonym of black colored tumor – is derived from the so-
called chromaffi n reaction, resulting from oxidation of stored catecholamines. Adrenal tumors
are usually referred to as pheochromocytomas (because of a positive chromaffi n reaction),
whereas the extra-adrenal ones are alternatively designated extra-adrenal pheochromocytoma
or paraganglioma, the latter name usually being reserved for parasympathetic or nonfunctional
(i.e., non catecholamine-secreting) sympathetic tumors. Paraganglioma is also used to describe
the parasympathetically aligned tumors. However, since these neoplasms are otherwise
indistinguishable, and the chromaffi n reaction appeared to be a poor indicator of catecholamine
storage, the terminology may be confusing. For this reason, in this thesis, all sympathicoadrenal
neoplasms will be referred to as pheochromocytomas. Additional designations (e.g.,
nonfunctional, extra-adrenal, or malignant) will be used when appropriate. Neoplasms arising
from parasympathetic paraganglionic tissues will be referred to as paragangliomas. In the
literature, some of the latter may have been referred to as chemodectomas, glomus jugulare, or
carotid body tumors
Synthesis and use of a lysolecithin analog for the purification of UDP-glucuronosyltransferase.
Effect of a Nacelle on the Low-speed Aerodynamic Characteristics of a Swept-back Wing
Wind-tunnel tests of a simplified nacelle on a semispan wing having approximately 35 degrees of sweepback were made at low speeds to evaluate the effects of the nacelle on the aerodynamic characteristics of the wing. Force, moment, and pressure-distribution measurements are presented for the nacelle underslung and centrally mounted on the wing and mounted on a strut below the wing
On a Generalization of the Frobenius Number
We consider a generalization of the Frobenius Problem where the object of
interest is the greatest integer which has exactly representations by a
collection of positive relatively prime integers. We prove an analogue of a
theorem of Brauer and Shockley and show how it can be used for computation.Comment: 5 page
Modified Delphi survey for the evidence summarisation of patient decision AIDS: Study protocol
Ultrasmall InGa(As)P dielectric and plasmonic nanolasers
Nanolasers have great potential as both on-chip light sources and optical
barcoding particles. We demonstrate ultrasmall InGaP and InGaAsP disk lasers
with diameters down to 360 nm (198 nm in height) in the red spectral range.
Optically pumped, room-temperature, single-mode lasing was achieved from both
disk-on-pillar and isolated particles. When isolated disks were placed on gold,
plasmon polariton lasing was obtained with Purcell-enhanced stimulated
emission. UV lithography and plasma ashing enabled the fabrication of nanodisks
on a wafer-scale, with intended random size variation. Silica-coated nanodisk
particles generated stable sub-nanometer spectra from within biological cells
across an 80 nm bandwidth from 635 to 715 nm.Comment: 25 pages, 5 main figures, 8 supplementary figures, 3 supplementary
table
Frequent germ-line succinate dehydrogenase subunit D gene mutations in patients with apparently sporadic parasympathetic paraganglioma
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