Sporotrichosis in the Orinoco river basin of Venezuela and Colombia.

Six cases of sporotrichosis from the Orinoco river basin of Venezuela and Colombia are described; two are of the localized cutaneous type and four are lymphocutaneous. Diagnosis was based on the patient's clinical history and mycological culture. Epidemiology and distinctive cultural habits of the patients are discussed in connection with disease etiology.

In vitro activation of neutrophils by suspensions of Mycobacterium leprae.

Activation, defined as an increase in the proportion of cells that reduce nitroblue-tetrazolium in vitro, is present in neutrophils from patients with reactional lepromatous leprosy but not in neutrophils from patients with non-reactional lepromatous leprosy. Neutrophils from patients with all forms of leprosy are equally well activated by endotoxin in vitro. We have now shown that in vitro activation induced by Mycobacterium leprae suspensions is of comparable magnitude in neutrophils from patients with all forms of leprosy (including lepromatous and reactional lepromatous leprosy). There is no intrinsic neutrophil anergy in patients with lepromatous leprosy vis-à-vis M. leprae as pertains to activation. Spontaneous activation in reactional lepromatous leprosy is likely due to an indirect mechanism, probably of immunologic nature, and not simply to the presence of circulating Mycobacterium leprae in the blood.

Polymorphonuclear activation in leprosy. I. Spontaneous and endotoxin-stimulated reduction of nitroblue tetrazolium: effects of serum and plasma on endotoxin-induced activation.

Spontaneous nitroblue tetrazolium (NBT) reduction was evaluated in neutrophils from patients with the different types and forms of leprosy, and compared with reduction obtained form cells from normal controls. Leucocytes from the same subjects were stimulated in vitro by endotoxin, and the rise in percentage of cells reducing NBT was determined. Patients of all groups, with the exception of those with reactional lepromatous leprosy (RLL) had an essentially normal proportion of reducing cells. Neutrophils were normally activated by endotoxin. This indicates that while Mycobacterium leprae does not by itself stimulate leucocytes from leprosy patients, there is no overall anergy of neutrophils in lepromatous or other forms of leprosy. In RLL the proportion of reducing cells was significantly raised. Stimulation with endotoxin was able further to enhance this proportion, but not above levels reached by stimulation of normal cells. Neutrophil activation could not be reproduced by mixing serum from highly activated RLL patients with normal leucocytes. An inhibitory effect of serum and plasma over in vitro endotoxin activation of neutrophils was found.