Delipidation and reactivation of UDPglucuronosyltransferase from rat liver

UDPglucuronosyltransferase was solubilized by treating Wistar rat liver microsomes with deoxycholate. Chromatography of this preparation on Bio-Gel P-30 resulted in extraction of 92% of phospholipids and complete loss of enzyme activity. UDPglucuronosyltransferase was reactivated by dialysing this delipidated preparation in the presence of lecithin, a mixture of liver microsomal lipids or microsomal preparations from livers of UDPglucuronosyltransferase-deficient Gunn rats. Virtually complete enzyme reactivation was obtained with regard to glucuronidation and glucosidation of bilirubin; however, the inactivation of UDPglucuronosyltransferase with p-nitrophenol as substrate was irreversible. These findings demonstrate that UDPglucuronosyltransferase with bilirubin as substrate is a lipid-requiring enzyme.     

Leishmania mexicana in C3H mice: BCG and levamisole treatment of established infections

The effect of BCG and levamisole on the course of established murine leishmaniasis was examined. C3H mice infected subcutaneously in the perinasal region with 10(5) L. mexicana promastigotes produced chronic non-ulcerating, non-healing lesions and demonstrated positive humoral and delayed hypersensitivity responses to leishmanial antigens. Infected animals were treated during months 3-5 of infection with either live BCG or with levamisole. Neither treatment resulted in resolution of lesions or in production of a hyperallergic form of infection; similarly, neither immune responses to leishmanial antigens nor histopathological features of lesions were significantly altered. BCG treatment resulted in accelerated growth of primary leishmanial lesions and in the appearance of metastases in some animals. Levamisole treatment of uninfected animals resulted in low levels of antibodies reacting with promastigote antigens, but not in positive delayed intradermal responses. BCG induced delayed intradermal sensitivity to PPD in both infected and control animals; significantly increased delayed reactions to leishmania, were observed in treated uninfected mice.     

Constituents of West African medicinal plants. XXX. Tridictyophylline, a new morphinan alkaloid from Triclisia dictyophylla

Triclisia dictyophylla Diels (Menispermaceae) is a woody climber indigenous to West Africa which has been used natively as a medicinal in the treatment of several ailments. Chromatography of an extract of the whole plant afforded tridictophylline (3), a new morphinan alkaloid whose structure was established by a consideration of spectral data and confirmed by x-ray crystallographic analysis. The bisbenzylisoquinoline dibenzodioxin alkaloids cocsuline (1) and trigilletimine (2) were also isolated from the same extract.     

The relative effects of selective intra-arterial and intravenous vasopressin infusion

The relative effects of selective intra-arterial and intravenous infusions of vasopressin were evaluated in 16 normotesive dogs. One group was infused via the left gastric artery, one was infused via a peripheral vein, and a control group was not infused. Flow to the stomach and bowel was reduced by an average of 73% and 45%, respectively. There was no significant difference between selective intra-arterial and intravenous infusions with regard to their effects on visceral flow or their systemic parameters. Control animals demonstrated only minor variations from base-line flow.     

Step-tracking movements of the wrist. IV. Muscle activity associated with movements in different directions

We examined the patterns of muscle activity associated with multiple directions of step-tracking movements of the wrist in humans and monkeys. Human subjects made wrist movements to 12 different targets that required varying amounts of flexion-extension and radial-ulnar deviation. Wrist muscles displayed two patterns of electromyographic (EMG) modulation as movement direction changed: amplitude graded and temporally shifted. The amplitude-graded pattern was characterized by modulation of the quantity of muscle activity that occurred during two distinct time periods, an agonist burst interval that began before movement onset and an antagonist burst interval that began just after movement onset. The timing of muscle activity over the two intervals showed little variation with changes in movement direction. For some directions of movement, EMG activity was present over both time intervals, resulting in "double bursts." Modulation of activity during the agonist burst interval was particularly systematic and was well fit by a cosine function. In contrast, the temporally shifted pattern was characterized by a gradual change in the timing of a single burst of muscle activity. The burst occurred at a time intermediate between the agonist and antagonist burst intervals. The temporally shifted pattern was seen less frequently than the amplitude-graded pattern and was present only in selected wrist muscles for specific directions of movement. Monkeys made wrist movements to 8-16 different targets that required varying amounts of flexion-extension and radial-ulnar deviation. These movements were performed more slowly than those of human subjects. The wrist muscles of the monkeys we examined displayed the amplitude-graded pattern of activity but not the temporally shifted pattern. Stimulation of individual wrist muscles in monkeys resulted in wrist movements that were markedly curved, particularly for the wrist extensors. These results indicate that step-tracking movements of the wrist are generated mainly by using the amplitude-graded pattern to modulate muscle activity. We propose that this pattern reflects a central process that decomposes an intended movement into an agonist, "propulsive" component and an antagonist, "braking" component. Separate bursts of muscle activity then are generated to control each component. On the other hand, we argue that the temporally shifted pattern may function to reduce the amount of movement curvature associated with the activation of wrist muscles.