The teratogenic effects of 5-fluoro-2-desoxyuridine (F.U.D.R.) on the Wistar rat fetus with particular reference to cleft palate. (49/255)

The teratogenic effects of 5-fluoro-2-desoxyuridine on Wistar rat fetuses were studied macroscopically, microscopically and ultrastructurally. In no case did palatal shelf elevation occur, and a palatal shelf elevating force could not be demonstrated in freshly-removed fetuses. The shelves, like the connective tissues generally, showed clear evidence of depressed mucopolysaccharide synthesis. The shelves eventually ossified in the vertical position, and in some cases their free edges fused with the lateral wall of the oral cavity (palato-oral fusion). The results were consistent with the mucopolysaccharide-turgor hypothesis advanced by the author in a previous paper to account for normal shelf elevation. Phocomelia, brain and limb bud haemorrhages, gross subcutaneous oedema, hyperextension of the cranial base, fused vertebrae, detached epithelia, bizarre brain abnormalities (including some remarkable attempts at neural reconstitution) and growth and ossification of the mandible in the virtual absence of Meckel's cartilages were also noted in these fetuses.  (+info)

Low oxygen tension stimulates the redifferentiation of dedifferentiated adult human nasal chondrocytes. (50/255)

OBJECTIVE: To determine the effect of dissolved oxygen tension (DO) on the redifferentiation of dedifferentiated adult human nasal septum chondrocytes cultured as pellets. DESIGN: After isolation, human nasal chondrocytes were expanded in monolayer culture, which resulted in their dedifferentiation. Dedifferentiated cells were pelleted, transferred to a bioreactor and maintained for up to 21 days at 100% DO (21% oxygen), 25% DO (5.25% oxygen) or 5% DO (1% oxygen), which was controlled in the liquid phase. Redifferentiation was assessed by staining the extracellular matrix with safranin-O and by the immunolocalization of collagen types I, II, IX and of a fibroblast membrane marker (11-fibrau). In addition, glycosaminoglycans (GAG) and DNA content were determined spectrophotometrically. RESULTS: In monolayer culture, cells dedifferentiated and multiplied 90- to 100-fold. Cell pellets cultured in a bioreactor under conditions of low oxygen tension (25% DO or 5% DO) stained intensely for GAGs and for collagen type II, but very weakly for collagen type I. After 14 days of culturing, cell pellets maintained at 5% DO stained more intensely for collagen IX and more weakly for 11-fibrau than did those incubated at 25% DO. After 21 days of culturing the GAG content of cell pellets maintained at 5% DO was significantly greater than that of those incubated at 25% DO. Under air-saturated conditions (100% DO), the DNA and GAG contents of cell pellets decreased with time in culture. After 21 days of culturing, both parameters were substantially lower in cell pellets maintained at 100% DO than in those incubated at low oxygen tensions. The staining signals for collagen types II and IX were much weaker, and those for the markers of dedifferentiation (collagen type I and 11-fibrau) much stronger under air-saturated conditions than at low oxygen tensions. CONCLUSION: These observations demonstrate that using the present set-up, low oxygen tension stimulates the redifferentiation of dedifferentiated adult human nasal chondrocytes in pellet cultures.  (+info)

Two-deoxyglucose as an anti-metabolite in human carcinoma cell line RPMI-2650 and drug-resistant variants. (51/255)

The accumulation of 2-deoxyglucose (2-DG), a glycolytic inhibitor, was investigated in a human nasal carcinoma cell line, RPMI-2650 and two of its drug-resistant variants (selected with taxol and melphalan) to assess manipulation of glycolytic potential as a selective means of reducing resistance. 2-DG uptake was increased 3-fold and 9.9-fold in taxol- and melphalan-resistant variants of RPMI-2650, respectively. Two of the principal factors associated with increased 2-DG uptake, namely glucose transporters and hexokinase activity, were increased in the resistant variants. Other changes in glucose metabolism that may affect 2-DG as an antimetabolite were observed, including increases in glucose-6-phosphate dehydrogenase of 10-fold and 100-fold for taxol- and melphalan-resistant variants, respectively, suggesting higher pentose phosphate activity; increased glutamine utilisation and greater sensitivity to iodoacetic acid-induced depletion of ATP levels in the parent relative to the resistant variants.  (+info)

A cost-effectiveness analysis of conventional and nurse-led telephone follow-up after nasal septal surgery. (52/255)

BACKGROUND: The need to bring down costs while maintaining a high standard of care has led to the expansion in the role of nurses in recent years. METHODS: We present results of cost-effectiveness analysis of conventional and nurse-led telephone follow-up after nasal septal surgery. RESULTS AND CONCLUSIONS: Our results indicate that the substitution of nurse-led telephone follow-up for conventional out-patient follow-up has the potential for substantial cost reduction and decreased out-patient access times in the NHS.  (+info)

Giant cell reparative granuloma of the nasal cavity. (53/255)

We report an unusual case of giant cell reparative granuloma (GCRG) arising in the nasal cavity of a 7-year-old girl. GCRG is an uncommon benign lesion that is most commonly found in the mandible and maxilla. The MR imaging and CT findings of this lesion, as well as GCRGs in other craniofacial bones and extragnathic sites, will be reviewed. Although rare, the imaging characteristics of GCRGs should be recognized, and this entity should be suggested when the clinical information, CT, and MR features suggest a fibrous-osseous lesion in the nasal cavity.  (+info)

Nasal septal abscess as a complication of laser inferior turbinectomy. (54/255)

Postoperative infections are infrequent following laser inferior turbinate surgery. We report a 52-year-old man with a Klebsiella pneumoniae nasal septal abscess as a complication of potassium-titanium-phosphate 532-nm laser turbinectomy. To our knowledge, this is the first report of such a potentially serious complication resulting from minor ambulatory intranasal surgery. The clinical presentation, pathogenesis, and management of nasal septal abscesses are discussed.  (+info)

Molecular organization of the olfactory septal organ. (55/255)

The septal organ in the mammalian nose is a distinct chemosensory organ sitting in the air path. To gain insights into its organization and function, we analyzed the chemoreceptors expressed in this area. By combining cDNA cloning, Affymetrix (Santa Clara, CA) genechips covering all the mouse olfactory receptor genes, and in situ hybridization, we achieved a relatively complete expression profile of the olfactory receptor genes in the septal organ. The majority of the septal neurons express only a few receptor genes in varying patterns, with the top one in approximately 50% of the cells and the top eight together in approximately 93% of the cells. We demonstrated that a single neuron expresses only one receptor by a thorough combination of all the major septal receptor genes in double-labeling studies. These septal receptor genes do not form a single subfamily. Instead, these genes are distributed on a few major branches of the phylogenetic tree covering all the mouse olfactory receptors. Most of these genes are also concentrated in certain areas within the most ventral zone of the main olfactory epithelium, although their expression patterns do not match those in the septal organ. In contrary to the previous view of random distribution, our results indicate that certain olfactory receptors form "hot spots" in the nose.  (+info)

PHR1, a PH domain-containing protein expressed in primary sensory neurons. (56/255)

Previously, we identified PHR1 as an abundantly expressed gene in photoreceptors and showed that it encodes four isoforms, each with N-terminal pleckstrin homology (PH) and C-terminal transmembrane domains. To better understand PHR1 function and expression, we made a Phr1 null mouse by inserting a beta-galactosidase/neor cassette into exon 3. In addition to photoreceptors, we found abundant expression of specific Phr1 splice forms in olfactory receptor neurons and vestibular and cochlear hair cells. We also found Phr1 expression in cells with a possible sensory function, including peripheral retinal ganglion cells, cochlear interdental cells, and neurons of the circumventricular organ. Despite this discrete expression in known and putative sensory neurons, mice lacking PHR1 do not have overt sensory deficits.  (+info)