Inhibition of phagocytosis and chemiluminescence in human leukocytes by a lipid soluble factor in normal tissues.

Homogenates of normal rat tissues inhibited several functional parameters of normal human peripheral blood leukocytes, including luminol-dependent chemiluminescence induced by both soluble (phorbol myristate acetate) and particulate (Escherichia coli) stimuli; in vitro uptake of radiolabeled E. coli; and in vitro phagocytosis and killing of E. coli. The doses of rat tissue protein that caused a 50% inhibition of leukocyte chemiluminescence were ca. 6.2 micrograms for small intestine, 83 micrograms for kidney; 100 micrograms for heart; 132 micrograms for liver, 190 micrograms for skeletal muscle, and 307 micrograms for brain. The putative phagocytosis inhibitor (PI) in rat liver was more plentiful in particulate fractions than in the cytosol. The PI activity in the original or Miranol-solubilized rat liver homogenate was nondialyzable, and it was reduced substantially by heating at 90 degrees C for 30 min but not at 56 degrees C for 30 min. It was unaffected by aprotinin, a potent inhibitor of proteolytic activity. Treatment of tissues with trypsin did not reduce PI activity, whereas treatment with phospholipase A2 clearly increased it. The bulk (up to 88%) of PI in rat liver or small intestine could be extracted by lipid solvents, e.g., diethyl ether. Purified fatty acids were potent inhibitors of leukocyte chemiluminescence; other lipids had little or no inhibiting activity. The various data suggest that (i) normal tissues contain a potent PI and (ii) that the PI is a lipid moiety.     

Improved radioaerosol administration system for routine inhalation lung imaging.

An improved radioaerosol administration system has been developed to reduce the number of droplets larger than 2.0 micron in diameter which have caused abnormal hyperdeposition of inhaled aerosols in the large airways. The new system has achieved this goal by interposing a reservoir-setting bag in the aerosol delivery line between the nebulizer and the patient. The components are inexpensive, commercially available and easily assembled in any nuclear medicine service.     

Effect of dietary chronic cadmium exposure on cell-mediated immune response in rhesus monkey (Macaca mulatta)

Rhesus monkeys (Macaca mulatta) were daily exposed orally to cadmium (Cd) at 5 mg/kg body wt in diet for a period of 2 and 6 months. Significant amount of Cd accumulated in liver, kidney and spleen after its exposure to monkeys. Cell mediated immune response was assessed by the responsiveness of peripheral blood lymphocytes (PBL) to phytohemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM). Even after 6 months of exposure, Cd increased DNA synthesis, although not significantly, in unstimulated and mitogen stimulated lymphocytes. Stimulation Index (SI), however, decreased largely due to increased unstimulated [( 3H]thymidine incorporation) observed after Cd exposure. It, therefore, indicates that Cd is not immunosuppressive in primates, phylogenetically closer to humans.     

Wasted leg syndrome: a clinical, electrophysiological and histopathological study

Forty cases of 'wasted leg syndrome' were studied clinically and electrophysiologically. Muscle biopsy was examined in nine cases, majority of patients were adults engaged in heavy manual work. The illness was noticed incidently with a strictly unilateral wasting of the whole lower limb (in 65% of cases), of all muscles below the knee (in 22.5% of cases) or of quadriceps muscles only (in 12.5% of cases). The nerve conduction studies and the electromyographic pattern suggested anterior horn cell disorder. Neurogenic atrophy was seen in 7 out of 9 muscle biopsies. A follow up in 12 patients (2-6 years) revealed no progression of the disease. It is suggested that possibly these cases represent an entity, clinically different from other anterior horn cell disorders.