Johne's disease is a condition that refers to chronic granulomatous enteritis in ruminants. It is believed that survival and replication of Mycobacterium (M.) paratuberculosis in mononuclear phagocytes plays an important role in the pathogenesis of Johne's disease. However, it is not clear how M. paratuberculosis survives for long time periods in mononuclear phagocytes, nor is it clear which factors trigger multiplication of these bacilli and result in the development of Johne's disease. Investigating the intracellular fate of M. paratuberculosis is challenging because of its very slow growth (more than two months to form visible colonies on media). Existing animal models also have limitations. Despite those obstacles, there has been progress in understanding the intracellular survival tactics of M. paratuberculosis and the host response against them. In this review, we compare known aspects of the intracellular survival tactics of M. paratuberculosis with those of other mycobacterial species, and consider possible mycobactericidal mechanisms of mononuclear phagocytes.
Animals ; Leukocytes, Mononuclear/*microbiology ; Mycobacterium avium subsp. paratuberculosis/*physiology ; Phagocytes/*microbiology

BACKGROUND/AIMS: Heart rate variability (HRV) is a method for evaluation of autonomic nervous system activity by expressing the balance of sympathetic and parasympathetic tones. Some studies of HRV in patients with end-stage renal disease (ESRD) have been performed in Korea. However, few have examined kidney transplantation (KT) patients. Therefore, we investigated autonomic nervous system activity by means of HRV in patients with KT due to ESRD. METHODS: We compared the pattern of cardiac sympathetic and parasympathetic activity by time- and frequency-domain analysis of HRV with 24-h Holter monitoring of 23 KT and 56 dialysis patients. Patients underwent KT between January, 2008 and June, 2011. RESULTS: The mean ages of KT and dialysis patients were 54.2 +/- 12.3 and 53.7 +/- 12.6 years, respectively. The KT group showed increased time- and frequency-domain HRV (including HRV index), very low frequency (VLF), means and standard deviations of all normal R-R intervals for all 5-min segments of the entire recording (SDNNi), low frequency (LF), LF in normalized units (LF norm), and LF to high-frequency power ratio, compared with the dialysis group. CONCLUSIONS: Autonomic tone in patients with KT is higher than that in patients with ESRD on dialysis.
Autonomic Nervous System ; Dialysis ; Electrocardiography ; Electrocardiography, Ambulatory ; Heart ; Heart Rate ; Humans ; Kidney ; Kidney Failure, Chronic ; Kidney Transplantation ; Korea