Two views of the addiction elephant: comment on McSweeney, Murphy, and Kowal (2005)

F. K. McSweeney, E. S. Murphy, and B. P. Kowal present a convincing case that the literature on habituation and sensitization to the sensory properties of conventional reinforcers is relevant to understanding a variety of addictive behaviors. They note that their model has advantages over a number of alternative formulations. However, in discussing one particular such alternative, a Pavlovian conditioning analysis of drug tolerance and withdrawal, F. K. McSweeney et al. overstate the advantages of their reinforcer habituation/sensitization model.     

Relapsing polychondritis studied by computed tomography

Computed tomographic findings in a patient with relapsing polychondritis are described. Collapse of the cartilage of the nose and calcification in cartilages of the ears were clearly demonstrated. CT scanning was also helpful in evaluating the tracheobronchial tree for airway compromise, which could prove fatal in this condition.     

IMMUNOLOGICAL IDENTIFICATION OF FOOT-PAD ISOLATES AS MYCOBACTERIUM LEPRAE BY LEPROMIN REACTIVITY IN LEPROSY PATIENTS

Lepromin, a product containing Mycobacterium leprae from patients' tissues, fails to elicit skin reactions in lepromatous patients; this non-reactivity was utilized as a means of identifying the mycobacterium isolated in mouse foot-pads from leprosy patients. To do this a suspension of acid-fast bacilli prepared from mouse foot-pads infected with a typical isolate was compared to human lepromin. The isolate was in fourth passage, and the multiplication since first isolation had diluted the original inoculum to insignificant levels. Three preparations were tested: A, A foot-pad preparation containing 1.6 x 10⁷ organisms/ml, B, lepromin diluted to the same bacillary content, and C, undiluted lepromin containing 4.2 x 10⁷ organisms/ml. The reactions were compared in 34 lepromatous and 30 tuberculoid patients. All 34 lepromatous patients were negative in both early (Fernandez) and late (Mitsuda) reactions to all 3 antigens. In the tuberculoid patients the late reactions were positive in 66.7, 70.0 and 90.0 per cent to antigens A, B, and C, respectively. The size of the reactions to A and B were closely correlated in the individual patients. Experience in leprosy patients with suspensions prepared from 16 other mycobacterial cultures is reported or reviewed. None of them produced reactions that correlated with those of lepromin. Thus the lack of reactivity to lepromin of lepromatous patients appears to be a specific phenomenon. The results provide evidence that the foot-pad isolates and M. leprae are immunologically identical.