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9-beta-d-Arabinofuranosyladenine (ara-A) has been found to specifically inhibit the growth of Sphaerotilus natans and Beggiatoa sp. at a low concentration (0.78 mug/ml). The nucleoside had no antimicrobial activity against various microorganisms other than Candida albicans at 1,000 mug/ml. 3'-Deoxyadenosine, 2'-deoxyadenosine, formycin, and some derivatives of ara-A also showed inhibitory activity against Sphaerotilus natans. The growth of Beggiatoa sp. was also inhibited by 9-beta-arabinofuranosylhypoxanthine, 3'-deoxyadenosine, 2'-deoxyadenosine, formycin, toyocamycin, tubercidin, and some derivatives of ara-A. ara-A was quite stable in water and had no harmful effect on fish at 200 mug/ml. The possible uses of ara-A and some nucleosides in controlling the proliferation of S. natans and Beggiatoa sp. in the environment are discussed.

Selective growth inhibitors of Sphaerotilus natans were detected in the culture broths of several strains of Streptomyces. Anslimins A and B were isolated from the culture broth of Streptomyces oganonensis by adsorption on resinous adsorbent followed by elution with 50% aqueous acetone. The A and B components were then separated by cellulose powder chromatography. Physicochemical parameters of anslimins A and B revealed that these compounds are new peptide-containing structures. Anslimins A and B inhibited growth of S. natans at 0.78 and 0.39 mug/ml, respectively, but showed no activity against any of the other test microorganisms at 100 to 200 mg/ml. The anslimins had no harmful effect on guppies at a concentration of 100 mg/liter.

The inhibitory effects of ketanserin and spiroperidol (a neuroleptic drug) on the contractile response of isolated rat uterus to serotonin (5-HT) were investigated. Ketanserin caused non-competitive inhibition of the contractile response to 5-HT and showed more selective inhibition than the other 5-HT antagonists tested. The inhibitory effect of spiroperidol was comparable with the effects of classical 5-HT antagonists. These results suggest that ketanserin and spiroperidol selectively inhibit the contractile response of isolated rat uterus to 5-HT.

A mutant of Streptomyces saganonensis No. 4075, obtained with N-methyl-N'-nitro-N-nitrosoguanidine treatment, produced herbicidins F and G without herbicidins A and B. Isolation of the antibiotics was performed by adsorption on resinous adsorbent followed by elution with aqueous MeOH. Herbicidin F was obtained as colorless needles after extraction of the eluate using methylene dichloride. Purification of herbicidin G was completed with silica-gel chromatography to give a crystalline powder. physico-chemical characterization revealed that herbicidins F and G were new nucleoside antibiotics having an adenine moiety in their structures. There was no inhibition activity at 100 micrograms/ml of herbicidins F and G against all of bacteria and yeast tested. Herbicidin F, as well as herbicidin G, are inhibitory activity against some of fungi such as Tricophyton rubrum (MIC; 6.25 micrograms/ml), T. asteroides (6.25 micrograms/ml), T. mentagrophytes (6.25 approximately 12.5 micrograms/ml), Botrytis cinerea (12.5 micrograms/ml), Blastomyces brasiliensis (12.5 approximately 25 micrograms/ml).

The chloramphenicol resistance of Streptococcus haemolyticus, Streptococcus pneumoniae and Streptococcus faecalis isolated from clinical materials was proved to be due to an inactivating enzyme produced by these bacteria. The inactivated products of chloramphenicol were identified as 1-acetoxy, 3-acetoxy and 1,3-diacetoxy derivatives by thin-layer chromatography and infrared spectroscopy. The responsible enzyme was thus confirmed to be chloramphenicol acetyltransferase. The enzyme was inducible. It was partially purified by ammonium sulfate precipitation, DEAE-cellulose chromatography and gel filtration on Sephadex G-150. The enzymes obtained from S. haemolyticus, S. pneumoniae and S. faecalis have been compared with the conclusion that they are identical with respect to molecular weight (approximately 75,000-80,000), optimum pH and heat stability.

A phospholipid that differs from known active lipids and causes potent platelet aggregation and weak hypotension has been isolated from bovine brain. Its platelet aggregating effect on heparinized platelet-rich plasma from rabbits, was at a threshold concentration of about 0.2 nmol ml-1 as phosphorus. The effect was inhibited by CV-3988. The phospholipid was converted by diazomethane treatment to another active lipid that caused short-term hypotension, but not platelet aggregation, rather it inhibited the aggregation of rabbit heparinized platelets induced by platelet-activating factor.

Strain Au-3, a mutant of Streptomyces hygroscopicus subsp. aureolacrimosus, obtained with ultraviolet irradiation, was a high-yield strain of milbemycins D, E, F, G and H. Fermentation studies on the strains were conducted in shake flasks and 30-liter jar fermentors. Isolation of the metabolites was performed by adsorption on resinous adsorbent followed by elution with aqueous MeOH and separated by silica gel column chromatography. Milbemycin D was obtained as colorless needles after recrystallization and milbemycins E, F, G and H were purified to homogeneity by column chromatography. Physico-chemical characterization revealed that milbemycins D, E, F, G and H were new antibiotics possessing the 16-membered macrocyclic lactone with a 6,6-membered spiroketal ring system.

The cloned cDNAs encoding the four subunits of the Torpedo californica acetylcholine receptor, each carried by a simian virus 40 vector, direct the synthesis of the functional receptor in a combined expression system consisting of COS monkey cells and Xenopus oocytes. Our results suggest that all four subunits are required to elicit a normal nicotinic response to acetylcholine, whereas only the alpha-subunit is indispensable for alpha-bungarotoxin binding activity.

Strain Rf-107, a mutant of Streptomyces hygroscopicus subsp. aureolacrimosus, obtained with ultraviolet irradiation, produced two new macrolide antibiotics, milbemycins J and K without production of any of the other milbemycins described in the previous paper. Fermentation studies on the strain were conducted in shake flasks and 30-liter jar fermentors. Isolation of the antibiotics was performed by adsorption on resinous adsorbent followed by elution with aqueous MeOH. Purification of milbemycins J and K was completed with Lobar Si 60 column chromatography to give colorless crystals. Physico-chemical data, such as UV, IR and NMR spectra are described. Milbemycins J and K were readily converted by the intact cells of the parent strain to milbemycins alpha 1 and alpha 3, respectively. Physico-chemical characterization and the bioconversion studies revealed that milbemycins J and K were new antibiotics having the 16-membered macrocyclic lactone with a 6,6-membered spiroketal ring system.

A placental form of membrane-bound neutral arylamidase was found in the tissue of renal cell carcinoma. Membrane-bound neutral arylamidases from renal cell carcinoma, an intact part of the same kidney and placenta, had the same molecular weight (240 000) and were identical with respect to KM value and effect of inhibition by chelators or amino acids. Membrane-bound neutral arylamidase from renal carcinoma had the same electrophoretic mobility and heat stability as placental membrane-bound neutral arylamidase, but differed from kidney membrane-bound neutral arylamidase with respect to electrophoretic mobility, heat stability and susceptibility to urea inactivation. Results suggest the carcinoplacental alterations in membrane-bound neutral arylamidase isoenzyme in renal cell carcinoma.

Platelet activating factor induced slow, but sustained contraction of isolated rat colon in a dose-dependent manner. The contraction persisted even when the strips were washed several times with Tyrode solution. However, the addition of high concentrations of bovine serum albumin to the washing solution led to the rapid relaxation of the strips to the basal level, possibly by removing platelet activating factor tightly bound to rat colon. These strips then responded normally to a second addition of platelet activating factor. Neither the cholinergic nervous system nor release of histamine, serotonin, prostaglandins or leukotriene D4 were significantly involved in the contraction induced by platelet activating factor. FR-900452 and CV-3988, recently found to be antagonists of platelet activating factor, selectively blocked the contraction of rat colon induced by the active phospholipid, indicating that it induced contraction by a direct stimulatory effect on the smooth muscle of rat colon in a receptor-mediated manner.

The biosynthetic relationship of the herbicidins produced by Streptomyces saganonensis was studied with blocked mutants by means of a bioconversion method using growing and resting cells. It is proposed that the biosynthetic sequence for herbicidins is; herbicidin G----herbicidin F----herbicidin A. Both herbicidins A and F were converted to herbicidin B by non-enzymatic reactions. Herbicidin G was also converted to herbicidin C non-enzymatically.

Two different cDNA clones encoding mouse tyrosinase (monophenol oxygenase, E.C. 1.14.18.1) were isolated from B16 melanoma cells, and their primary structure was determined. One of the cDNAs consists of 3309 nucleotides with an open reading frame coding for a peptide of 533 amino acids. The other cDNA is approximately 1600 nucleotides long, with a shorter 3'-untranslated region and a deduced in-frame deletion of 77 amino acid residues with respect to the former clone. Neither of these clones is structurally identical to other described mouse tyrosinase cDNAs (1-3). RNA blotting analysis demonstrates that multiple tyrosinase mRNA species are not only present in B16 melanoma, but also in normal skin melanocytes.

The effect of verapamil on K-stimulated 45Ca uptake (the difference between uptake in 60 mM-Ko medium and 5 mM-Ko medium) was studied using a synaptosomal fraction from rat brain. Verapamil inhibited K-stimulated 45Ca uptake, but not 45Ca uptake in 5 mM-Ko media (1 mM- and 0.1 mM-Cao media). The concentrations of verapamil inducing 50% inhibition of K-stimulated 45Ca uptake (ID50) in 1 mM- and 0.1 mM-Cao media were not significantly different, being about 10(-4) M and 2 X 10(-4) M, respectively. Like verapamil, Mn++ inhibited only K-stimulated 45Ca uptake, but its ID50 values in 1 mM- and 0.1 mM-Cao media were about 1.7 mM and 0.2 mM, respectively. It is considered from these findings that both verapamil and Mn++ specifically inhibit K-stimulated 45Ca uptake, but the modalities of their inhibitory effects on K-stimulated 45Ca uptake are different.

A radioimmunoassay for the measurement of aminopeptidase (microsomal) (AP) in human serum was developed by using antiserum to human kidney AP. AP purified from kidney and AP present in normal serum and in serum from a patient with obstructive jaundice gave parallel logit-log transformation lines, suggesting immunological identity. The mean concentration of AP in normal serum (n = 104) was 1.33 +/- 0.30 (mean +/- SD) micrograms/ml. Men had significantly higher serum AP levels (1.41 +/- 0.30 micrograms/ml) (p less than 0.005) than women (1.24 +/- 0.28 micrograms/ml). Serum AP levels of patients with hepatoma (2.26 +/- 0.87 micrograms/ml) and cancer of the pancreas or the biliary tract (2.90 +/- 0.67 micrograms/ml) were significantly higher (p less than 0.005) than those of normal subjects. Patients with acute and chronic hepatitis (2.06 +/- 0.66 micrograms/ml) also had significantly higher serum AP levels (p less than 0.005) than normal subjects. In pregnant women, however, the increase in AP activity without the increase in AP concentration showed that the increased AP activity was due to an enzyme other than AP. The enzyme levels and activities in normal serum as well as in patients' sera were significantly correlated (normal, r = 0.77; patients, r = 0.95). Based on the specific activity of AP purified from human plasma, the enzyme activity splitting L-alanyl-beta-naphthylamide is due almost completely to AP in normal subjects and in patients with hepatobiliary diseases.

Streptomyces saganonensis No. 4075 used for production of herbicidins A and B has also produced other two antibiotics, herbicidins C and E in submerged culture. Isolation of the antibiotics was performed by adsorption on resinous adsorbent followed by elution with aqueous MeOH and completed by silica-gel chromatography. Physico-chemical characteriation revealed that herbicidins C and E are new nucleoside antibiotics having an adenine moiety in their structures. Herbicidins C and E indicated inhibitory activity against germination of chinese cabbage at 12.5 micrograms/ml and 25 micrograms/ml, respectively, and Anacystis nidulans, a blue green algae, at 100 approximately 200 micrograms/ml.

Bonnamycin which is a new tetracycline group antibiotic isolated from a variant strain of Streptomyces rimosus and is identified chemically as doxycycline was investigated, comparing with tetracycline. The results are as follows: (1) In in vitro studies of anti-bacterial spectrum, doxycycline is widely effective against standard strains kept in our department. (2) The distribution of susceptibility of 75 Staphylococci, 62 Salmonella and 64 Shigella strains isolated from clinical materials was similar to that of tetracycline. (3) As to the therapeutic experiment in acute infection of Klebsiella pneumoniae in mice, the drugs were equally effective and the ED50 was both 70.8 mcg. (4) Doxycycline administrated orally or subcutaneously in rats was distributed in kidneys, livers, lungs and spleens at relatively high concentration among organs.

The biosynthetic origins of the carbon skeleton of milbemycins alpha 2, alpha 4 and D were studied. 13C Labeled antibiotics, milbemycins alpha 2, alpha 4 and D, were isolated from the culture broth of Streptomyces hygroscopicus subsp. aureolacrimosus strain Au-3 after feeding [1-13C]acetate, [1-13C]-propionate, [3-13C]propionate, [1-13C]isobutyrate, DL-[2-13C]valine and L-[methyl-13C]methionine, and 13C NMR spectra of the antibiotics thus obtained were measured. It was revealed that the carbon skeleton, except for carbon 25, of milbemycins alpha 2, alpha 4 and D are derived from seven acetate units and five propionate units. It was also shown that the methyl, ethyl and isopropyl groups at carbon 25 in milbemycins alpha 2, alpha 4 and D are derived from acetate, propionate and isobutyrate or DL-valine, respectively, and the methyl carbon of the methoxy group at carbon 5 in milbemycins alpha 2 and alpha 4 was enriched by L-[methyl-13C]methionine.

A membrane-bound arylamidase from well-differentiated hepatocellular carcinoma having the same electrophoretic mobility as placental membrane-bound arylamidase was found. The enzyme was found to be a sialoprotein and was activated by Co2+. Hepatoma membrane-bound arylamidase had a similar molecular weight (240 000) and kinetic properties to normal liver membrane-bound arylamidase, but differed from the liver enzyme with respect to electrophoretic mobility, heat stability and urea inactivation.