Current asthma is often diagnostically excluded by the presence of normal bronchial responsiveness. We report on a TDI-induced occupational asthma patient with normal bronchial responsiveness. He had suffered from shortness of breath during and after TDI exposure for several months. His initial methacholine bronchial challenge test showed a negative response. The bronchoprovacation test with TDI showed an isolated immediate bronchoconstriction. The following methacholine bronchial challenge tests revealed that the bronchial hyperresponsiveness developed seven hours after the TDI challenge (methacholine PC20:5.1 mg/ml), progressed up until 24 hours, and returned to normal on the seventh day. This case provides evidence that the response of the airway to TDI may not always be accompanied by bronchial hyperresponsiveness to methacholine. Screening programs utilizing methacholine challenges may not always identify TDI-sensitized asthmatic workers.
Adult ; Asthma/*chemically induced/diagnosis ; Bronchial Provocation Tests ; Bronchoconstriction/*drug effects ; Humans ; Male ; Methacholine Chloride/*diagnostic use ; Occupational Diseases/*chemically induced ; Skin Tests ; Time Factors ; Toluene 2,4-Diisocyanate/*adverse effects

BACKGROUND/AIMS: Although metalic stents are established therapeutic options for the palliation of malignant biliary obstruction, it remains unclear which stricture or stent related factors affect the stent patency. METHODS: Metallic Wallstents (Microvasive, Boston-Scientific, MA, U.S.A.) were inserted endoscopically in 68 patients (mean age; 70.2+/-8.5, M:F=38:30) with malignant biliary obstruction. Patency rates were prospectively analyzed according to the characteristics of malignant strictures including length, morphologic type and degree of stricture. Furthermore, patient age, initial serum bilirubin level, the length of stent, the adequate expansion time, and the location of the distal stent end were evaluated as possible factors affecting the stent patency. Stent patency was assessed using the survival analysis of the Kaplan-Meier estimation and Cox regression analysis. RESULTS: Median overall stent patency was 231 days and overall rate of stent occlusion was 41.2% (28/68). The causes of stent blockage were tumoral ingrowth in 23 patients (33.8%), distal overgrowth of the cancer in 3 (4.4%), proximal overgrowth in 1 (1.5%) and sludge incrustation in 1 patient (1.5%). No significant differences in metallic stent patency rates according to primary tumor type, length and morphologic type of stricture, and length and location of distal end of the stent were found. Log-rank test and multivariate regression analysis, however, demonstrated that the degree of stricture assessed by cannula or guidewire passage and the adequate expansion time of the stent are independent factors associated with long-term metallic stent patency. CONCLUSIONS: Our study showed that early expansibility of the stent and easy passage of larger-caliber instruments over the stricture were favorable factors for long-term patency of the metallic stent.
Bilirubin ; Catheters ; Constriction, Pathologic ; Humans ; Prospective Studies ; Sewage ; Stents*

Purpose: To assess patient radiation doses during diagnostic and therapeutic neurointerventional procedures from multiple centers and propose dose reference level (RL). Materials and Methods: Consecutive neurointerventional procedures, performed in 22 hospitals from December 2020 to June 2021, were retrospectively studied. We collected data from a sample of 429 diagnostic and 731 therapeutic procedures. Parameters including dose-area product (DAP), cumulative air kerma (CAK), fluoroscopic time (FT), and total number of image frames (NI) were obtained. RL were calculated as the 3rd quartiles of the distribution. Results: Analysis of 1160 procedures from 22 hospitals confirmed the large variability in patient dose for similar procedures. RLs in terms of DAP, CAK, FT, and NI were 101.6 Gy·cm2, 711.3 mGy, 13.3 minutes, and 637 frames for cerebral angiography, 199.9 Gy·cm2, 3,458.7 mGy, 57.3 minutes, and 1,000 frames for aneurysm coiling, 225.1 Gy·cm2, 1,590 mGy, 44.7 minutes, and 800 frames for stroke thrombolysis, 412.3 Gy·cm2, 4,447.8 mGy, 99.3 minutes, and 1,621.3 frames for arteriovenous malformation (AVM) embolization, respectively. For all procedures, the results were comparable to most of those already published. Statistical analysis showed male and presence of procedural complications were significant factors in aneurysmal coiling. Male, number of passages, and procedural combined technique were significant factors in stroke thrombolysis. In AVM embolization, a significantly higher radiation dose was found in the definitive endovascular cure group. Conclusion Various RLs introduced in this study promote the optimization of patient doses in diagnostic and therapeutic interventional neuroradiology procedures. Proposed 3rd quartile DAP (Gy·cm2) values were 101.6 for diagnostic cerebral angiography, 199.9 for aneurysm coiling, 225.1 for stroke thrombolysis, and 412.3 for AVM embolization. Continual evolution of practices and technologies requires regular updates of RLs.