Effect of acriflavin on the kinetoplast of Leishmania tarentolae. Mode of action and physiological correlates of the loss of kinetoplast DNA

The loss of kinetoplast DNA in Leishmania tarentolae, which occurs in the presence of low concentrations of acriflavin, was found to be a result of selective inhibition of replication of this DNA. Nuclear DNA synthesis was relatively unaffected and cell and kinetoplast division proceeded normally for several generations. An approximately equal distribution of parental kinetoplast DNA between daughter kinetoplasts resulted in a decrease in the average amount of DNA per kinetoplast. The final disappearance of the stainable kinetoplast DNA occurred at a cell division in which all the remaining visible kinetoplast DNA was retained by one of the daughter cells. The selective inhibition of kinetoplast DNA synthesis was caused by a selective localization of acriflavin in the kinetoplast. The apparent intracellular localization of dye and the extent of uptake at a low dye concentration could be manipulated, respectively, by varying the hemin (or protoporphyrin IX) concentration in the medium and by adding red blood cell extract (or hemoglobin). Hemin and protoporphyrin IX were found to form a complex with acriflavin. During growth in acriflavin, cells exhibited an increasing impairment of colony-forming ability and rate of respiration. No change in the electrophoretic pattern of total cell soluble proteins was apparent. The data fit the working hypothesis that the loss of kinetoplast DNA leads to a respiratory defect which then leads to a decrease in biosynthetic reactions and eventual cell death. A possible use of the selective localization of acriflavin in the kinetoplast to photooxidize selectively the kinetoplast DNA is suggested.

THORACOPLATY AT THE KWANGJU CHRISTIAN HOSPITAL

In the past five years 26 patients have had a thoracoplasty at the Kwangju Christian Hospital. Twenty-two cases had an apiccelysis in addition to thoracoplasty(semb), 65 cases had a classical thoracoplasty(Alexander), 6 patients had a Shade thoracoplasty, and three patients had a thoracoplasty following the pulmonary resection. For purposes of analysis the 6 Shade thoraco-plastics are excluded. In the other 90 cases. 73 were male and 17 were female. Half of the patients were under thirty and no patient was over sixty. The operative mortality was 1.1%, only one patient having died. In 174 operations on the 90 patients 18 wound infections occurred, for an overall infection rate of 10%. Recently we have been draining the subscapular space with a catheter attached to suction for 48 hours. In these cases there have been 19 first stage operations with only one wound infection(5%) and 17 second stage operations with no wound infections. Therefore we are hopeful that this catheter drainage method will decrease our wound complication rate. Only one patient was lost to follow-up. Eighty-six percent of the patients achieved sputum conversion and are presumed arrested. In general about three out of four patients who did convert to sputum negative, did so in the first three or four months after operation. Two patients died with discase(2.2%) and eight patients are as yet sputum positive more than one year after operation. These are considered as probable failures.

Toxic Impurities in Nalgene Filter Units

Sterile disposable filter units made of Nalgene contain an impurity which inhibits the growth of the protozoan, Leishmania tarentolae, in a defined medium.