Citations

Objectives To develop a method to quantify nasal tissue resilience, to establish the normal range for persons without nasal obstruction, and to measure the changes in tissue resilience resulting from standard open rhinoplastic techniques. Methods A new device is described that determines nasal tissue resilience. Measurements on the nasal tip were obtained in triplicate at 5 distinct anatomical sites. Normal values (N = 60) were stratified for both sexes into 3 different age groups. Preoperative and postoperative measurements were also obtained in 6 patients who underwent open rhinoplasty for airway obstruction. One patient who underwent intranasal valve repair was included for comparison. All operative patients underwent preoperative and postoperative rhinomanometric measurements. Results Across all age and sex groups the anterior septal angle is the firmest area of the nasal tip. The mean tissue resilience over the interdomal area and the midcolumella is significantly greater in men than in women. The resilience of the interdomal area exhibits an age effect, with decreasing stiffness over time. The postoperative changes seen correlate well with the placement of structural grafts during rhinoplasty. Conclusions Nasal tip support can be quantified. Normative values have been established, which allow one to identify areas of inadequate tip support in persons with nasal obstruction. Alterations in tip support resulting from surgical intervention can be quantified. Open rhinoplasty techniques are an excellent tool to restore deficiencies in nasal tip support.

ABSTRACT The circumstances under which unintegrated lentivirus DNA can persist and be a functional template for transcription and protein expression are not clear. We constructed and validated the first class I (nonpleiotropic) integrase (IN) mutants for a non-human lentivirus (feline immunodeficiency virus [FIV]) and analyzed both these and known class I human immunodeficiency virus type 1 IN mutants. The FIV IN mutants (D66V and D66V/D118A) had class I properties: Gag/Pol precursor expression, proteolytic processing, particle formation, and reverse transcriptase (RT) production were normal, while the transduction of dividing fibroblasts was prevented and integration was blocked. When injected into rat retinas, the wild-type (WT) vector produced extensive, persistent transgene expression, compared with only rare positive neuronal cells for the IN mutant vector. In contrast, both WT and mutant vectors produced entirely equivalent, effective transduction levels of primary rat neurons (retinal ganglion cells). By testing the hypothesis that the unexpected retinal neuron transduction was related to cell cycle status, we found that when fibroblasts were growth arrested, transduction and internally promoted transgene expression were not inhibited at all by the class I FIV or HIV-1 IN mutations. Cells were then transduced under aphidicolin arrest and were released from the block 48 h later. Vector expression was stable and durable during repeated passaging in WT vector-transduced cells, while the release of cells transduced with equivalent RT units of class I IN mutant FIV or HIV vector resulted in a steady decline of expression, from 97 to 0% of cells by day 10. Southern blot and PCR analyses showed a lack of integration, irrespective of cell cycle, for the class I mutants and an increase in one- and two-long terminal repeat circular and linear unintegrated DNAs in growth-arrested cells. We conclude that if cell division is prevented, unintegrated FIV and HIV-1 vector DNAs can produce high-level internally promoted transgene expression equivalent to WT vectors. The expression correlates with the unintegrated DNA levels. These observations may facilitate the study of the roles of IN and other preintegration complex components in preintegration phases of infection by (i) providing an alternative way to monitor unintegrated nuclear cDNA forms, (ii) restricting ascertainment to the transcriptionally functional subset of unintegrated DNA, (iii) enabling analysis in individual, nondividing cells, and (iv) uncoupling other potential functions of IN from integration.

Rupture of an intracranial aneurysm (subarachnoid hemorrhage) is a potentially devastating condition frequently complicated by delayed cerebral ischemia from sustained contraction of intracranial arteries (cerebral vasospasm). There is mounting evidence linking the formation of intracranial aneurysms and the pathogenesis of post-subarachnoid hemorrhage vasospasm to aberrant bioavailability and action of the vasodilator molecule nitric oxide generated by isoforms of nitric oxide synthase. In humans, the gene encoding the endothelial isoform of nitric oxide synthase (eNOS) is known to be polymorphic, with certain polymorphisms associated with increased cardiovascular disease susceptibility. In this prospective clinical study involving 141 participants, we used gene microarray technology to demonstrate that the eNOS gene intron-4 27-base pair variable number tandem repeat polymorphism (eNOS 27 VNTR) predicts susceptibility to intracranial aneurysm rupture, while the eNOS gene promoter T-786C single nucleotide polymorphism (eNOS T-786C SNP) predicts susceptibility to post-subarachnoid hemorrhage vasospasm. We believe that genetic information such as this, which can be obtained expeditiously at the time of diagnosis, may be used as a helpful adjunct to other clinical information aimed at predicting and favorably modifying the clinical course of persons with intracranial aneurysms.

Acute injury to the intestinal mucosa is a major dose-limiting complication of abdominal radiation therapy. We studied the role of the transcription factor NF-κB in protection against radiation-induced apoptosis in the intestinal epithelium in vivo . We use mice in which NF-κB signaling through IκB-kinase (IKK)-β is selectively ablated in intestinal epithelial cells to show that failure to activate epithelial cell NF-κB in vivo results in a significant increase in radiation-induced epithelial cell apoptosis. Furthermore, bacterial lipopolysaccharide, which is normally a radioprotective agent, is radiosensitizing in IKKβ-deficient intestinal epithelial cells. Increased apoptosis in IKKβ-deficient intestinal epithelial cells was accompanied by increased expression and activation of the tumor suppressor p53 and decreased expression of antiapoptotic Bcl-2 family proteins. These results demonstrate the physiological importance of the NF-κB system in protection against radiation-induced death in the intestinal epithelium in vivo and identify IKKβ as a key molecular target for radioprotection in the intestine. Selective preactivation of NF-κB through IKKβ in intestinal epithelial cells could provide a therapeutic modality that allows higher doses of radiation to be tolerated during cancer radiotherapy.

Both inducible nitric oxide (NO) synthase (iNOS) and cyclooxygenase-2 (COX-2) have been implicated in the biliary tract carcinogenesis. However, it is not known whether these inflammatory mediators are induced by interdependent or parallel pathways. Because iNOS activity has been associated with diverse gene expression, the aim of this study was to determine whether iNOS induces COX-2. To address this objective, immortalized, but nonmalignant, murine cholangiocytes, 603B cells were employed for these studies. Both iNOS and COX-2 protein and mRNA were expressed in these cells. However, iNOS inhibition with either N-[3-(aminomethyl) benzyl]acetamidine or stable transfection with an iNOS antisense construct inhibited COX-2 mRNA and protein expression, an effect that was reversed by NO donors. COX-2 mRNA expression in 603B cells was reduced by pharmacological inhibitors of the p38 MAPK and JNK1/2 pathways. In contrast, neither inhibitors of the soluble guanylyl cyclase inhibitor/protein kinase G nor p42/44 MAPK pathways attenuated COX-2 mRNA expression. Finally, 603B cells grew at a rate threefold greater than 603B-iNOS antisense cells. The low growth rate of 603B-iNOS antisense cells could be restored to near that of the parent cell line with exogenous PGE2. In conclusion, iNOS induces COX-2 expression in cholangiocytes, which promotes cell growth. COX-2 induction may contribute to iNOS-associated carcinogenesis.