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The use of whole mounts in the electron microscope study of Micromonospora chalcea is a rapid and simple method for obtaining morphologic information about both the spore and sporophore. Spore anomalies were observed by this method, and their anatomical basis was confirmed by thin sections. Spore shape and surface ornamentation varied with the age of the spore and should be taken into consideration when characterizing and comparing the spores of various isolates. The spore of M. chalcea is not an endospore as found either in the bacilli or in the thermoactinomycetes; it lacks the multilaminar inner coat found in these thermoresistant spores. The spore of M. chalcea appears to contain an outer coat, or possibly coats, and a less electron-dense, thick inner coat or cortex. The spore of M. chalcea differs from the spore of streptomycetes in lacking a sheath around the hyphal wall. This sheath surrounding the hyphal wall in streptomycetes contains the spore ornamentation such as spines or hairs, but in M. chalcea spore ornamentation arises in the outer portion of the spore wall as wart-like protuberances. The spore of M. chalcea appears t o develop its coats in a centripetal fashion similar t o streptomycetes.Cross walls in M. chalcea are double and appear to develop in a manner similar t o streptomycetes in which the hyphal wall appears to "peel apart," the inner portions being continuous with the cross walls. Mesosomes and nuclei found in thin sections of M. chalcea appear similar to those found in streptomycetes and other gram-positive bacteria. The electron microscope data obtained for M. chalcea ATCC 12452 in this study appear to be representative of the morphologic and anatomical features found in other species of Micromonospora that we have studied.Spore silhouettes made by direct electron microscope observations of unfixed, unstained, or shadowed whole specimens have been used for characterization and comparison of the spores of species of actinomycete genera, in particular the genus Streptomyces (41, 44). These silhouettes, while useful for characterization and comparison of morphology, leave unanswered a number of anatomical questions as to what is internally responsible for the external morphology. These anatomical questions can be answered through the time-consuming method of fixation, embedding, thin sectioning, and staining. In this study an attempt was made to correlate morphology Micromonospora chalcea is the type species of the genus Micrornonospora (drskov (27), and ATCC 12452 has been designated as the neotype strain (29). Since the type species usually has an important bearing on our concept of the genus, we have studied in detail the structures and anomalies observed in this strain. Based upon this information and other workers' observations (M. W. Rancourt, Ph.D. thesis, Rutgers Univ., New Brunswick, N.J., 1963; references 1, 2, 20), an expanded descriptio:, for the genus Micromonospora is recommended. MATERIALS AND METHODS(silhouettes) with anatomy (thin sections), for this is important if the...

Rat neutrophils isolated from 4-h reverse passive Arthus reaction (RPAR) pleural exudates actively metabolize arachidonic acid via cyclooxygenase and lipoxygenase. Utilizing this system, the effect of oral doses of nonsteroidal antiinflammatory drugs on the ability of these cells to produce HHT, 5-HETE, and LTB from exogenously added arachidonic acid has been investigated. In vitro and ex vivo, indomethacin and timegadine inhibit cyclooxygenase activity in rat pleural neutrophils. In vitro, timegadine is a lipoxygenase as well as a cyclooxygenase inhibitor. This dual inhibition is confirmed by the observation that ex vivo timegadine inhibits the production of lipoxygenase as well as cyclooxygenase metabolites. While indomethacin, a cyclooxygenase inhibitor, primarily inhibits edema formation, the inhibition of both pathways of arachidonic acid metabolism by timegadine is reflected in the drug's ability to reduce cellular influx as well as edema formation in the RPAR pleural cavity inflammatory reaction.

Following in vitro incubation of flank organs from male golden Syrian hamsters with sodium [1‐14C] acetate, sebaceous glands and appendage‐freed epidermis were obtained by treating the flank organ tissue with calcium chloride. This method permitted the study of incorporation of carbon‐14 into the lipids of these skin components. Extracted lipids were identified by thin layer chromatography and autoradiography and were quantitated by liquid scintillation counting. Mono‐, di‐, and triglycerides, free sterols, fatty acids, wax monoesters, and squalene were identified as products of sebaceous gland metabolism of labeled acetate. In marked contrast, little incorporation of14C into triglycerides by the epidermal preparations was noted, although the epidermal lipids showed higher relative proportions of free sterols and polar lipids (including phospholipids). Accumulation of sterol esters did not occur. In both preparations phosphatidylcholine represented the major labeled phospholipid.