Evaluation of chest radiography and low-dose computed tomography as valuable screening tools for thoracic diseases.

BACKGROUND: Recent studies have shown that low-dose computed tomography (LDCT) is effective for the early detection of lung cancer. However, the utility of chest radiography (CR) and LDCT for other thoracic diseases has not been as well investigated as it has been for lung cancer. This study aimed to clarify the usefulness of the veridical method in the screening of various thoracic diseases. METHODS: Among individuals who had received general health checkups over a 10-year period, those who had undergone both CR and LDCT were selected for analysis. The present study included 4317 individuals (3146 men and 1171 women). We investigated cases in which abnormal opacity was detected on CR and/or LDCT. RESULTS: A total of 47 and 124 cases had abnormal opacity on CR and LDCT, respectively. Among these, 41 cases in which the abnormal opacity was identified by both methods contained 20 treated cases. Six cases had abnormalities only on CR, and none of the cases required further treatment. Eighty-three cases were identified using LDCT alone. Of these, many cases, especially those over the age of 50 years, were diagnosed with thoracic tumors and chronic obstructive pulmonary disease, which required early treatment. In contrast, many cases of pulmonary infections have improved spontaneously, without any treatment. CONCLUSION: These results revealed that LDCT allowed early detection of thoracic tumors and chronic obstructive pulmonary disease, especially in individuals over the age of 50 years. CR is still a useful imaging modality for other thoracic diseases, especially in individuals under the age of 49 years.

Increase in hepatic NKT cells in leukocyte cell-derived chemotaxin 2-deficient mice contributes to severe concanavalin A-induced hepatitis.

Leukocyte cell-derived chemotaxin 2 (LECT2) was originally identified for its possible chemotactic activity against human neutrophils in vitro. It is a 16-kDa protein that is preferentially expressed in the liver. Its homologues have been widely identified in many vertebrates. Current evidence suggests that LECT2 may be a multifunctional protein like cytokines. However, the function of LECT2 in vivo remains unclear. To elucidate the role of this protein in vivo, we have generated LECT2-deficient (LECT2(-/-)) mice. We found that the proportion of NKT cells in the liver increased significantly in LECT2(-/-) mice, although those of conventional T cells, NK cells, and other cell types were comparable with those in wild-type mice. Consistent with increased hepatic NKT cell number, the production of IL-4 and IFN-gamma was augmented in LECT2(-/-) mice upon stimulation with alpha-galactosylceramide, which specifically activates Valpha14 NKT cells. In addition, NKT cell-mediated cytotoxic activity against syngeneic thymocytes increased in hepatic mononuclear cells obtained from LECT2(-/-) mice in vitro. Interestingly, the hepatic injury was exacerbated in LECT2(-/-) mice upon treatment with Con A, possibly because of the significantly higher expression of IL-4 and Fas ligand. These results suggest that LECT2 might regulate the homeostasis of NKT cells in the liver and might be involved in the pathogenesis of hepatitis.

Peripheral nervous system involvement complicated due to vasculitis in cases of primary Sjögren's syndrome: case studies in a single hospital and a literature review.

Abstract To determine the background features of peripheral nervous system (PNS) involvement in cases of primary Sjögren's syndrome (SS), we studied the nervous system involvement, mainly that of PNS, in patients with primary SS who were admitted to our hospital during a period of 19 years. Nine of 82 admitted patients with primary SS had PNS involvement and 12 had central nervous system (CNS) involvement. Among 182 secondary SS patients, 25 had CNS involvement, and none had PNS involvement. The nine patients with PNS involvement were older and their disease duration was shorter than those with CNS involvement and either primary or secondary SS. Four patients exhibiting active progression of PNS involvement had concomitant vasculopathy clinically that was confirmed by nerve or skin biopsy examination, with an increase in the serum C-reactive protein level. According to the literature, among 17 reported SS patients with PNS involvement, 13 had primary SS, and 13 had vasculitis as confirmed by biopsy examination. Nervous system involvement in cases of SS is not rare. PNS involvement was observed mostly in elderly patients with primary SS, and its active progression was concomitant with vasculopathy.