Bronchiolitis obliterans (BO) is a clinical syndrome characterised by progressive small airway obstruction, causing significant morbidity and mortality. Central airway dilatation is one of its ...radiological characteristics, but little is known about the clinical and pathological associations between airway dilatation and BO.
This retrospective study consecutively included patients who underwent lung transplantation due to BO at Kyoto University Hospital from 2009 to 2019. Demographic and histopathological findings of the resected lungs were compared between patients with and without airway dilatation measured by chest computed tomography (CT) at registration for lung transplantation.
Of a total of 38 included patients (median age, 30 years), 34 (89%) had a history of hematopoietic stem-cell transplantation, and 22 (58%) had airway dilatation based on CT. Patients with airway dilatation had a higher frequency of
isolation with greater residual volume than those without airway dilatation. Quantitative CT analysis revealed an increase in lung volume to predictive total lung capacity and a percentage of low attenuation volume <-950 HU at inspiration in association with the extent of airway dilatation. Airway dilatation on CT was associated with an increased number of bronchioles with concentric narrowing of the lumen and thickening of the subepithelium of the walls on histology.
In patients with BO, airway dilatation may reflect increased residual volume or air trapping and pathological extent of obstructive bronchioles, accompanied by a risk of
isolation. More attention should be paid to the development of airway dilatation in the management of BO.
The 35 nm gate length CMOS devices with oxynitride gate dielectric and Ni salicide have been fabricated to study the feasibility of higher performance operation. Nitrogen concentration in gate ...oxynitride was optimized to reduce gate current I/sub g/ and to prevent boron penetration in the pFET. The thermal budget in the middle of the line (MOL) process was reduced enough to realize shallower junction depth in the S/D extension regions and to suppress gate poly-Si depletion. Finally, the current drives of 676 /spl mu/A//spl mu/m in nFET and 272 /spl mu/A//spl mu/m in pFET at V/sub dd/=0.85 V (at I/sub off/=100 nA//spl mu/m) were achieved and they are the best values for 35 nm gate length CMOS reported to date.
Ceftibuten undergoes H+-coupled uphill transport across rat small intestinal brush-border membrane vesicles. The effects of amino acids, peptides, folate, and beta-lactams on the uptake of ceftibuten ...were examined. Uptake of ceftibuten was competitively inhibited by dipeptides or tripeptides. A counter-transport effect on ceftibuten uptake was observed in the vesicle preloaded with these peptides, and the transport was temporarily against a concentration gradient (overshooting). On the other hand, ceftibuten uptake was not changed by amino acids and a tetrapeptide. Therefore, ceftibuten is predominantly transported via the oligopeptide transport system in the brush-border membranes. The relationship of ceftibuten transport to folate and other oral antibiotics was also investigated. Cyclacillin, cephradine, and cefadroxil exhibited both inhibitory and countertransport effects, but folate, cefaclor, and cephalexin showed only a slight inhibitory effect. As the transport of cefaclor showed no uphill uptake in the presence of a H+ gradient and its H+ stimulated uptake was small, a H+ gradient-independent carrier-mediated system seems to participate in its transport. These findings suggest that two different carrier-mediated transport systems, H+ gradient dependent and independent, may exist for oral cephems.
The transport characteristics of ceftibuten in rat intestinal brush-border membrane vesicles were investigated by a rapid filtration technique. Ceftibuten uptake was markedly stimulated by an ...inwardly directed H+ gradient (pH 7.5 inside, pH 5.5 outside) in comparison with that in the absence of a H+ gradient. The uptake at 30 sec was four times greater than that observed at equilibrium (overshoot phenomenon), while the H+ gradient-stimulated uptake of ceftibuten was markedly reduced in the presence of FCCP, a protonophore. These results suggested H+-coupled uphill transport of ceftibuten. In contrast, an inwardly directed Na+ gradient had no effect on ceftibuten uptake. The valinomycin-induced K+ diffusion potential (inside positive) significantly stimulated the ceftibuten uptake, suggesting net transfer of the negative charge. In contrast to the cis-isomer ceftibuten, the trans isomer of ceftibuten is not readily absorbed from the intestine, and its uptake was found not to be affected by a H+ gradient. Since the lipophilicity of the trans isomer is similar to that of ceftibuten, the uptake process appears to be stereoselective. The initial uptake of ceftibuten and its analogue cefaclor was concentration dependent under a H+ gradient. The apparent Km value was 0.2 mM for ceftibuten and 3.0 mM for cefaclor.
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