Enzymes of PEP-succinate pathway in Setaria cervi and effect of anthelmintic drugs

Localization of different enzymes of PEP-succinate pathway has been done in Setaria cervi, a bovine filarial worm. Succinate dehydrogenase and fumarate reductase were localized in mitochondria rich particulate fraction while all other enzymes were cytosolic. The in vitro effect of certain antifilarial/anthelmintic agents on these enzymes was also investigated. Sumarmin, at low concentration, could cause a marked inhibition of most of the enzymes of this pathway. Centperazine, an antifilarial drug being developed by CDRI showed significant inhibitory action on pyruvate kinase, lactate dehydrogenase, fumarase and succinate dehydrogenase while CDRI compound 72/70 showed significant inhibition of PEP-carboxykinase activity. Diethylcarbamazine and levamisole, however, were found to be more or less ineffective at lower concentrations against all the enzymes of this pathway.

Biomechanics of cervical spine facetectomy and fixation techniques

Facetectomy, either unilateral or bilateral, significantly altered the capacity of cervical spine functional units to withstand increasing compression-flexion loads applied in a constant mode to different specimen configurations. Unilateral facetectomy resulted in an average 31.6 +/- 9.7 percent decrease in strength whereas bilateral disruption caused an average 53.1 +/- 11 percent decrease in strength. Motion analysis in a two-dimensional plane after facetectomy indicated an anterior displacement of the instantaneous axis of rotation (IAR) with a resultant increased load on the vertebral bodies and disc. This anterior shift of the IAR in the horizontal plane was significantly but not completely resolved by wire fixation of the facet joints. These fixation techniques, consisting of either facet to facet or facet to spinous process wiring, demonstrated a similar capability to restore strength to the functional units as well as reducing excessive motion in the vertical and anterior axes induced by the facetectomies.

Effects of denervation on calpain and calpastatin in hamster skeletal muscles

Three leg muscles (soleus, extensor digitorum longus, and plantaris) of adult male golden Syrian hamsters were denervated by bilateral transecting of the sciatic nerve. Eighteen days after denervation, wet weights, amounts of soluble protein, and activities of wide-specificity calpain II, intermediate filament protein-specific calpain I, and calpastatin were measured by protein determination and enzyme and immunological assays. In comparison with control (nondenervated) muscles and depending on the specific muscle and protein, the activities of the calpains increased 1.3 to 1.9 times the control values, whereas the calpastatin decreased to one-half and one-third of control values. The muscle which showed the greatest increase in both calpain activities and the largest decrease in calpastatin activity was the plantaris (a fast-twitch, oxidative glycolytic muscle). The extensor digitorum longus (fast-twitch glycolytic) showed increases in calpain II activity similar to those in the plantaris, but smaller changes in calpain I and calpastatin. The soleus (slow-twitch, oxidative) showed the smallest changes in calpain II and calpastatin activities, although an increase in the calpain I activity was seen after denervation. These results suggest a possible relationship between the presence of fast-twitch, oxidative glycolytic fibers in a muscle and increased potential for intracellular proteolysis following denervation.

Paradoxical sleep characteristics and cultural environment. Preliminary results

The Temiars are a tribe of negroid pygmies of basically Proto-Malaysian affinities. Field-work in the Malaysian jungle provided some observations on the sleep-wakefulness cycle of two young Temiar adults. This cycle was monophasic circumstances permitting. Their rest-activity cycle at night was similar in the jungle and in the laboratory. Polygraphic total night-sleep recordings were made with both of them in the EEG laboratory in the Hospital Besar in Kuala Lumpur. The eye-movement frequencies of PS were compared with those from young adults of the West. Although the differences were not statistically significant, the Rem-densities of the Temiars were constantly at the low side. The significance of the results are being discussed.