Calcium-sensing receptor-mediated L-tryptophan-induced secretion of cholecystokinin and glucose-dependent insulinotropic peptide in swine duodenum

This study aimed to elucidate the effect of tryptophan (Trp) on gut hormone secretion as well as the roles of the calcium-sensing receptor (CaSR) and its downstream signaling pathway in gut hormone secretion by assessing swine duodenal perfusion in vitro. Swine duodenum was perfused with Krebs-Henseleit buffer as a basal solution. Various concentrations (0, 10, and 20 mM) of Trp were applied to investigate its effect on gut hormone secretion. A CaSR antagonist was used to detect the involvement of CaSR and its signal molecules. The 20 mM Trp concentration promoted the secretion of cholecystokinin (CCK) and glucose-dependent insulinotropic peptide (GIP), elevated the mRNA level of CaSR, and upregulated the protein levels of CaSR, protein kinase C (PKC), and inositol trisphosphate receptor (IP3R). However, NPS 2143, an inhibitor of CaSR, attenuated the CCK and GIP release, reduced the mRNA level of CaSR, and decreased the protein levels of CaSR, PKC, and IP3R with 20 mM Trp perfusion. The results indicate that CCK and GIP secretion can be induced by Trp in swine duodenum in vitro, and the effect is mediated by CaSR and its downstream signal molecules PKC and IP3R.

Primary tracheobronchial amyloidosis in China: Analysis of 64 cases and a review of literature / 华中科技大学学报（医学）（英德文版）

Primary tracheobronchial amyloidosis (TBA) is a rare pulmonary disease. A systematic review was performed on 64 cases of primary TBA in China and progress in the diagnosis and treatment of this disease is discussed. The Chinese biological and medical databases from 1970 to 2010 were searched and 75 cases of complete clinical and pathological data were identified. The clinical characteristics of the disease were summarized and longitudinal comparisons were made of diagnostic and treatment methods over time. The results showed that the morbidity associated with primary TBA has increased over recent years. The clinical manifestations were non-specific. Progressive dyspnea, cough and sputum were the most common symptoms. The percentage of patients undergoing computed tomography (CT) scan has increased over the years. The bronchoscopy and transbrochial lung biopsy (TBLB) were usually sufficient to establish the diagnosis. Treatment was reported for a total of 44 cases. Bronchoscopic Nd:YAG laser irradiation, argon plasma coagulation (APC) and drugs administration such as steroids and colchicines were reported to be effective in some patients. It is concluded that the demographic characteristics and clinical manifestations of primary TBA patients in China are largely consistent with findings reported in other countries. Dramatically more cases were reported in recent years, mainly due to the extensive application of bronchoscopy since 1990s. Chest CT scan provides important clues for the diagnosis of the disease. The definite diagnosis was confirmed by bronchoscopic findings and Congo red staining of biopsy specimen. Bronchoscopic Nd:YAG laser irradiation, argon plasma coagulation (APC) and drugs administration, such as steroids and colchicines were reported to be effective in some patients.