Inhibition of apoptosis in neuronal cells infected with Chlamydophila (Chlamydia) pneumoniae

Background Chlamydophila (Chlamydia) pneumoniae is an intracellular bacterium that has been identified within cells in areas of neuropathology found in Alzheimer disease (AD), including endothelia, glia, and neurons. Depending on the cell type of the host, infection by C. pneumoniae has been shown to influence apoptotic pathways in both pro- and anti-apoptotic fashions. We have hypothesized that persistent chlamydial infection of neurons may be an important mediator of the characteristic neuropathology observed in AD brains. Chronic and/or persistent infection of neuronal cells with C. pneumoniae in the AD brain may affect apoptosis in cells containing chlamydial inclusions. Results SK-N-MC neuroblastoma cells were infected with the respiratory strain of C. pneumoniae, AR39 at an MOI of 1. Following infection, the cells were either untreated or treated with staurosporine and then examined for apoptosis by labeling for nuclear fragmentation, caspase activity, and membrane inversion as indicated by annexin V staining. C. pneumoniae infection was maintained through 10 days post-infection. At 3 and 10 days post-infection, the infected cell cultures appeared to inhibit or were resistant to the apoptotic process when induced by staurosporine. This inhibition was demonstrated quantitatively by nuclear profile counts and caspase 3/7 activity measurements. Conclusion These data suggest that C. pneumoniae can sustain a chronic infection in neuronal cells by interfering with apoptosis, which may contribute to chronic inflammation in the AD brai

Seasonal benzathine penicillin G prophylaxis for recurrent streptococcal pharyngitis in children

WOS: 000074763400012PubMed ID: 9695301Background: To assess the efficacy of benzathine penicillin G (BPG) prophylaxis in recurrent streptococcal pharyngitis in children. Methods: One hundred and sixty children, aged 4-11 years, who experienced at least two episodes of group A beta-hemolytic streptococcal (GABHS) pharyngitis during a 4-month observation period between September and December 1995 were randomly divided into two groups. During the following 4-month period between January and April 1996, 80 children received BPG prophylaxis every 3 weeks as a single intramuscular injection of 1.2 million units for a body weight,greater than 27 kg and a half dose for 27 kg or less. Eighty children were accepted as a control group and were not given BPG prophylaxis. Results: The children in the BPG group experienced significantly less GABHS pharyngitis than those in the control group during the second 4-month period (16 vs 244 episodes, respectively, P < 0.001). BPG prophylaxis decreased streptococcal pharyngitis by 92% in the children in the study group, while the frequency of GABHS pharyngitis was unchanged in those in the control group during the second 4-month period compared with the first 4-month period. Conclusions: The data in the present study demonstrated that intramuscular BPG prophylaxis is very effective in preventing GABHS pharyngitis in children. it is recommended that it is used every 3 weeks in at least the fall-winter seasons in children susceptible to frequent GABHS pharyngitis