VACUUM DRYING OF STEAM STERILIZED DRESSINGS

SUMMARY: The degree of vacuum and time of application needed to dry steam sterilized dressings has been investigated. If the steam supply is dry, and the pressure in the drying stage is reduced to an absolute pressure of 50 mm Hg, dressings will be cool and dry without holding the vacuum, provided they are not damp before sterilization.     

X-ray and magnetic resonance stereotaxy for functional and nonfunctional neurosurgery

By means of new plastic stereotactic ring and head fixers, stereotactic procedures can be combined with MRI, with stereotactic coordinates obtained from the MRI images. The method was rechecked against CT stereotaxy and shows a good correspondence of the target coordinates. With MRI stereotaxy, structures near bony regions will be more accessible than with CT stereotaxy. Moreover, the MRI procedure seems to have advantages for functional therapy without the necessity of contrast ventriculography.     

Efferent projections of mesencephalic locomotor neurons in the cat

Efferent neuronal projections of the mesencephalic locomotor region were investigated in cats using a horseradish peroxidase retrograde axonal transport technique. It was found that neurons located within the locomotor area form ascending and descending projections to many structures of the spinal cord and the brain but that short-axon connections running to the reticular formation of the midbrain and the medulla predominate. Small numbers of long-axon fibers may merge into the locomotor strips of the medulla and the spinal cord. The locomotor regions of the two halves of the midbrain are interlinked.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 18, No. 1, pp. 117–125, January–February, 1986.     

Cloning of a rabbit erythroid-cell-specific lipoxygenase mRNA

We report the isolation of cDNA recombinants representing part of the rabbit reticulocyte (immature red blood cell, RBC) lipoxygenase (LOX) mRNA. One cDNA predicts an amino acid (aa) sequence matching exactly the unique N-terminal 30-aa sequence of the purified enzyme. Further, the reticulocyte mRNA, hybrid-selected by this recombinant, can be translated in vitro to give a polypeptide that comigrates with the purified reticulocyte LOX and is recognized by affinity-purified anti-RBC LOX polyclonal antibodies. Southern blotting experiments hybridising the RBC LOX cDNAs available to total rabbit genomic DNA digested with various restriction enzymes gives a fairly simple hybridisation pattern under moderate stringency conditions: moreover, the same pattern is obtained with a cloned fragment of genomic DNA containing the RBC LOX gene. This indicates that the RBC LOX gene is unique in the genome and seems not to be very closely related to the genes encoding the other tissue LOXs. We also show by Northern transfer/hybridisation experiments that the RBC LOX mRNA is expressed only in the red cell lineage but not in white blood cells (bone marrow or spleen) or in other non-erythroid cells tested (e.g., brain and lung).     

Block by phencyclidine of acetylcholine and barium induced adrenal catecholamine secretion

Activation of the sympathetic system by phencyclidine (PCP) should result in catecholamine release from the adrenals. However, adrenalectomy does not reduce PCP-induced hypertension. In an attempt to rectify this inconsistency, the direct effects of PCP on the bovine adrenal medulla were examined. At (3×10^?6M), PCP reduced the acetylcholine-(ACh)-induced catecholamine release by 50%. Surprisingly, barium-induced secretion of catecholamines was also reduced by PCP. ACh-induced catecholamine release was not altered by 10^?3M 4-aminopyridine (4 AP), the potassium channel blocker. Thus, calcium antagonist actions of PCP and consequent block of catecholamine secretion from adrenal medulla may explain the lack of effect of adrenalectomy on PCP-induced hypertension. Possible contributions of calcium and/or potassium channel blockade to other manifestations of PCP overdosage are discussed.