Synthesis and biological activities of leukotriene F4 and leukotriene F4 sulfone

Leukotriene F₄ (LTF₄ and LTF₄ sulfone have been synthesized and their biological activities determined in the guinea pig. LFT₄ displayed comparable activity to LTD₄ on guinea pig trachea and parenchyma but was less active on the ileum. When injected intravenously into the guinea pig, LTF₄ induced a bronchoconstriction (ED₅₀ 16 μg Kg⁻¹) which was blocked by indomethacin and FPL-55712 and was 50–100 X less potent than LTD₄ in this assay. LTF₄ sulfone was approximately 2–5 times less active than LTF₄ and . When injected into guinea pig skin with PGE₂ (100 ng); LTF₄ and LTF₄ sulfone (10–1000 ng) induced changes in vascular permeability. The order of potency in this assay was LTE₄ sulfone = LTD₄ = LTD₄ sulfone > LTE₄ > LTF₄ = LTF₄ sulfone.     

Relationship Between Plasma and Brain Tryptophan in Pigs During Experimental Hepatic Coma Before and After Hernodialysis with Selective Membranes

Experimental acute liver ischemia in pigs induces an increment in plasma free tryptophan with decreased total tryptophan. Brain tryptophan is elevated in all brain areas. A slight, but significant increase of brain serotonin is demonstrated in the striatum only, while 5-HIAA (5-hydroxyindoleacetic acid) is significantly lower in the hypothalamus. Other brain areas do not show significant changes in serotonin and 5-HIAA levels. Neither the high plasma free tryptophan levels, nor the decreased sum of neutral competitive amino acids are consistent with such an elevation of brain tryptophan. Hemodialysis was carried out with two different kinds of membranes: cuprophan (with an efficient removal of molecules up to molecular weight 1300) and AN 69 polyacrylonitrile (efficient removal up to 15,000). Ammonia and aminoacid clearance are similar for both membranes. After AN 69, plasmatic free tryptophan and brain tryptophan are lower than after liver devascularization, but still higher than normal. Serotonin significantly increases in the cortex, midbrain and hypothalamus without concomitant rise of 5-HIAA levels. After cuprophan hemodialysis, plasma total tryptophan is lower than in normal and even comatose animals, whereas free tryptophan is normal. Intracerebral tryptophan is similar to AN 69 dialysed animals, but in the hypothalamus it is similar to nondialysed animals. Brain serotonin levels are not modified. 5-HIAA decreases in the hypothalamus. This finding suggests that middle molecules (which are not cleared out with cuprophan hemodialysis) are involved in the intracerebral transfer of tryptophan and the metabolism of serotonin, mainly in the hypothalamus.     

BCG-induced granulomatous pulmonary inflammation and splenomegaly in mice: A T-cell-dependent response

When C57BL/6 mice were injected iv with BCG in an oil-in-saline emulsion, they developed intense pulmonary granulomatous inflammation (PGI) and splenomegaly as well as chemotactic activity for macrophages and angiotensin-converting enzyme (ACE) in their lung fluids. PGI, splenomegaly, and levels of chemotactic activity and ACE were markedly reduced in T-cell-deficient “B” mice. The capacity to develop PGI was fully restored and splenomegaly was partially restored in “B” mice by the provision of syngeneic thymocytes, spleen cells, or purified T cells. These results indicate that the full expression of BCG-induced PGI is dependent upon thymus-derived cells and is associated with high levels of chemotactic activity for macrophages and ACE in the lung lavage fluid. Although BCG-induced splenomegaly appears to be T cell dependent, it did not reach its full magnitude in reconstituted “B” mice.     

Production of Aseptic Spores of Vesicular-Arbuscular Endophytes and Their Viability After Chemical and Physical Stress

The survival of germinating spores of vesicular-arbuscular endophytes after treatments with oxidizing agents, antibiotics, moist heat, ultrasonic radiation, and ultraviolet radiation was compared with that of their contaminating microbes. Spores of three species were rapidly decontaminated by treatment with 0.42% (wt/vol) chlorine available from 5.0% (wt/vol) chloramine-T at 30°C for 20 to 40 min depending on the species and the soil from which they were extracted. This treatment did not change spore viability. The survival of spores was reduced by exposure for 20 min to 1.11% chlorine at 30°C for Glomus caledonius or at 35°C for Acaulospora laevis. Growth of any bacteria surviving treatment with oxidizing agents was inhibited by 100 μg of chloramphenicol per ml in agar; however, spore germination and germ tube growth were reduced only by concentrations greater than 200 μg/ml in agar. Spore germination was decreased by concentration of pimaracin, which controlled fungal growth. The spores survived moist heat at 40°C for 80 min, 55°C for 10 min, and 60°C for less than 1 min. The viability of spores was unaffected by ultrasonic irradiation for up to 4 min. Spores of G. caledonius and A. laevis were extremely resistant to ultraviolet radiation. Their viability was unaffected by exposure to 5 × 10⁸ ergs cm⁻² from an ultraviolet source of 253.7nm. The spores had very thick, pigmented walls, and the possibility that these provided some protection against the physical and chemical treatments is discussed. The degree of physiological damage to the spores caused by the treatments demonstrated some adverse effects of basic laboratory procedures. This information, together with that on the comparative sensitivity of contaminating microbes to the treatments, was used in the development of protocol for producing large numbers of uncontaminated spores.     

Chronic Hepatitis Associated with Drug Abuse: Significance of Hepatitis B Virus

One hundred and seventy-seven former heroin addicts, consisting of 85 who were newly admitted to a methadone maintenance program and 92 who had received methadone for a mean period of 30 months, were prospectively studied for up to 2 years in order to determine: (1) the effect of heroin withdrawal on the hepatic abnormalities, and (2) the incidence of HBsAg, anti-HBs, and anti-HCc as indices of the frequency of hepatitis B virus infection. Our study indicates that (1) hepatic abnormalities persist when heroin is discontinued and are not temporally related to drug and/or needle usage, and (2) that 71% of subjects had either HBsAg or anti-HBs; anti-HBc was tested for in 16 patients and was present in 100%, although 9 of the 16 were both HBsAg- and anti-HBs-negative. This study suggests that hepatitis B is largely responsible for the liver dysfunction. It is proposed that an abnormality in immune function, induced by heroin, is responsible for the high incidence of chronic hepatitis. Attention is drawn to the similarity between former drug addicts and hemophiliacs, since both develop chronic hepatitis in spite of anti-HBs in the serum.     

Structure-function relationship in hemoproteins: The role of cytochrome c 3 in the reduction of colloidal sulfur by sulfate-reducing bacteria

Cytochromes c ₃ of different strains of sulfatereducing bacteria have been purified and tested for their capacity to reduce colloidal sulfur to hydrogen sulfide. The results are in good agreement with the activities reported for the whole cells. Cytochrome c ₃ is the sulfur reductase of some strains of sulfate-reducing bacteria such as Desulfovibrio desulfuricans Norway 4 and sulfate-reducing bacterium strain 9974 from which the sulfur reductase activity can be purified with the cytochrome c ₃. In contrast, Desulfovibrio vulgaris Hildenborough cytochrome c ₃ is inhibited by the product of the reaction namely hydrogen sulfide. Chloramphenicol has no effect on the sulfur reductase activity of D. desulfuricans Norway 4 when resting cells grown on lactate-sulfate medium are put in the presence of colloidal sulfur. This shows that the sulfur reductase activity is constitutive and corresponds to the fact that colloidal sulfur grown cells do not contain more cytochrome c ₃ (or another sulfur reductase) than lactate-sulfate-grown cells.     

Microdetermination of monosaccharides in glycoproteins by gas-liquid chromatography

In a newly developed method for determining picomolar quantities of monosaccharides in glycoproteins, the methyl glycosides released by methanolysis of glycoproteins are separated as trifluoroacetates by gas-liquid chromatography and are detected with an electron capture detector. The application of the method has been demonstrated for the analysis of the carbohydrate moiety of secretory component isolated from human colostral immunoglobulin A.     

Biochemical research on oogenesis. RNA accumulation during oogenesis of the dogfish Scyliorhinus caniculus

Four biochemical mechanisms have been shown to operate in the oocytes of amphibians and teleosts: (1) amplification of the 28 S and 18 S genes, (2) noncoordinate accumulation of 5 S RNA and 28 S + 18 S RNA, (3) storage of 5 S and transfer RNA made in excess by small oocytes within nucleoprotein particles, (4) expression of different 5 S genes in oocytes and somatic cells. We have tried to extend these observations to another group of vertebrates, i.e., selacians (Chondrichthya). Our data suggest that ribosomal gene amplification is low or absent in the oocytes of the dogfish Scyliorhinus caniculus. However, previtellogenic oocytes of this species accumulate more 5 S RNA than needed for ribosome assembly. Transfer and 5 S RNA present in small oocytes are probably not free in the cell sap. A substantial fraction of these RNAs sediments at 10 S when homogenates of immature ovaries are centrifuged in sucrose density gradients. In contrast to what we observed in amphibians and teleosts, 5 S RNA from ovaries of S. caniculus is identical in sequence to 5 S RNA from liver. Among the four mechanisms mentioned above, the second and probably the third one are used by the oocytes of S. caniculus. Mechanism (4) is absent in this species. No definitive conclusion can be drawn concerning mechanism (1), i.e., ribosomal gene amplification.     

The fine structure of polychaete septate junctions

Summary Epidermal septate junctions of Nereis sp. and Cirriformia sp. fixed with OsO₄ or glutaraldehyde/OsO₄ display variable structure in electron micrographs. In transverse section the septa are often indistinct and obscured by opaque material that fills the junctional cleft. Septa (spaced at 180–280 Å) are more clearly defined in slightly oblique transverse section; they exhibit an electron lucent center and appear to be linked by arms. En face views of the junction show a honeycomb pattern. Cytoplasmic faces of junctional membranes are backed with plaques opposite the septa. Lanthanum used as a tracer delineates junctional structure in negative contrast. In transverse section a chain-like lattice is present in the junctional cleft. En face views show parallel rows of pleated elements often linked by arms into honeycomb arrays. Oblique sections demonstrate that these pleated elements are continuous with the chain-like lattice seen in transverse sections. Lanthanum does not pass entirely through the junction. Lanthanum reveals that the septa have a very intricate substructure, but it is difficult to visualize the architecture that could generate the various images presented by these junctions when seen in different orientations. However, it is clear that these junctions possess some features that are diagnostic of several supposedly different types of septate junctions in invertebrates.Supported by USPHS grants NIH 5 P01 NS-07512, NIH 2701 GM-00102, and NB-00840, and by a grant from the Pomona College Research CommitteeI thank Sarah Wurzelmann, Stanley Brown, Nancy Kelly, and Gerhard Ott for excellent technical assistance. Portions of this study were carried out while I was a Postdoctoral Fellow in the Department of Anatomy, Albert Einstein College of Medicine. I dedicate this article to Berta Scharrer as a token of appreciation and affection for her guidance, encouragement, inspiration, and example of excellence