Inhibition of concanavalin A-induced hepatic injury of mice by bacterial lipopolysaccharide via the induction of IL-6 and the subsequent reduction of IL-4: the cytokine milieu of concanavalin A hepatitis.

BACKGROUND/AIMS: Liver natural killer 1.1 antigen (NK1)+ T cells and IL-4 play a crucial role in concanavalin-A (Con-A)-induced hepatic injury in mice, and a T helper (Th) 2 immune response was thus suggested to be involved. This study was designed to examine the effect of bacterial lipopolysaccharide (LPS), a strong inducer of a Th 1 immune response, on Con-A hepatic injury and also to clarify further the cytokine milieu of Con-A hepatitis. METHODS: LPS were injected into mice before Con-A injection to evaluate the effect on hepatic injury. The effect of the pretreatment with various T1 and Th2 cytokines or anti-cytokine antibodies on Con-A hepatitis was also examined. RESULTS: LPS in quantities > or = 500 ng/mouse, when injected 24 h before Con-A injection, abrogated the Con-A-induced elevation of transaminases, hepatocyte destruction and serum IL-4 elevation. This LPS inhibitory effect was blocked when the mice were injected with either anti-IL-6 antibody before LPS injection or IL-4 before Con-A injection. IL-6, but neither IL-10 nor IL-12 pretreatment suppressed Con-A-induced IL-4 production and hepatitis. NK1+ T cells produced IL-4 while both NK1+ T cells and NK1- T cells produced IFN-gamma. Not only anti-IL-4 antibody but also the anti-IFN-gamma antibody pretreatment inhibited Con-A hepatitis. However, although the anti-IL4 antibody suppressed IL-4 alone, the anti-IFN-gamma Ab unexpectedly inhibited both IFN-gamma and IL-4 elevation, while IL-4 injection evoked a moderate Con-A hepatitis even in the anti-IFN-gamma antibody-treated mice. Furthermore, the IL-4 mutant mice did not develop Con-A hepatitis. CONCLUSION: LPS inhibited Con-A hepatitis by inducing IL-6 and thereby inhibited IL-4 synthesis from NK1+ T cells. Although both IL-4 and IFN-gamma were required for the full induction of Con-A hepatic injury, exogenous IL-4 evoked a moderate Con-A hepatitis, even in the absence of IFN-gamma.

Infantile disseminated visceral giant cell arteritis presenting as sudden infant death.

The rare clinicopathological entity 'disseminated visceral giant cell arteritis' (DVGCA) was first described in 1978. It is characterized by widespread small-vessel giant cell angitis and extravascular granulomas. A normal and healthy 7-month-old boy who presented unexpectedly with sudden infant death syndrome (SIDS) is reported. Histological examination at autopsy revealed giant cell angitis of the aorta, common carotid, coronary, pulmonary, celiac, mesenteric and common iliac arteries. There were also granulomas in the tracheal wall and liver. To our knowledge, this is the first documented case of DVGCA occurring in an infant younger than 12 months of age. A review of the literature on DVGCA is presented in this report, and the differential diagnosis is discussed.

Malignant fibrous histiocytoma of the bladder with focal rhabdoid tumor differentiation.

A case of primary malignant fibrous histiocytoma of the bladder is presented. This tumor involving the bladder is rare and the unusual histological features in the present case caused significant delay in accurate diagnosis. Since early diagnosis and aggressive surgical resection are essential to the effective treatment of this neoplasm, physicians should continually bear in mind the possibility of this malignant tumor whenever the pathological diagnosis is inconclusive.