Metabolites of mating pheromone,rhodotorucine A, by a cells of Rhodosporidiumtoruloides

Rhodotorucine $\text{A}$ which induces mating tube formation of $\text{a}$ cells in $\text{Rhodosporidium}\text{toruloides}$ is metabolized rapidly by $\text{a}$ cells. By use of labeled rhodotorucine $\text{A}$, the degradation was found to be proteolytic. Two peptide fragments Tyr-Pro-Glu-Ile-Ser-Trp-Thr-Arg and Asn-Gly-Cys(S-farnesyl) were identified as the metabolites. Proteolysis of the pheromone mainly occurred on the cell surface. Culture filtrate of $\text{a}$ cells at log phase did not metabolize rhodotorucine $\text{A}$.     

The argECBH-bearing EcoRI segment of the Escherichia coli chromosome

The transducing phage λd$\text{arg}\text{14}$, carrying a portion of the $\text{E. coli}$ chromosome including $\text{argECBH}$, is derived from the heat-inducible, lysis-defective strain λy199, which has the $\text{b}\text{519}$ and $\text{b}\text{515}$ deletions. Cleavage of λy199 DNA by $\text{Eco}$RI endonuclease, followed by agarose slab gel electrophoresis, results in bands corresponding to the known C, D, E, and F segments of λ, and a segment A′ (A plus B minus $\text{b}\text{519}$ minus $\text{b}\text{515}$, the cleavage site between A and B being eliminated). Cleavage of λd$\text{arg}\text{14}$ DNA by $\text{Eco}$RI yields the expected D, E, and F segments of λ and four other segments, termed 14-1 through 14-4, whose length is 17.5, 6.2, 3.0, and 2.0 kilobases, respectively, as determined by electron microscopy and corroborated by electrophoretic mobility. Heteroduplex analysis shows that the $\text{E. coli argECBH}$ cluster is on the 14-1 segment.     

An endodextranase inhibitor from batch cultures of Streptococcus,mutans

An inhibitor of $\text{Streptococcus}$,$\text{mutans}$ endodextranase was detected in proteins prepared from batch cultures of $\text{S.}$,$\text{mutans}$ strains representing serotypes $\text{a}$ through $\text{g}$. Affinity chromatography of strain 6715-49 proteins, which apparently were free of endodextranase activity, yielded an active endodextranase and, in a separate peak, the endodextranase inhibitor. The presence of the inhibitor in culture fluids accounts for the absence of endodextranase activity in batch-grown cultures of $\text{S.}$,$\text{mutans}$ known to produce this enzyme.     

OKY-1581: A selective inhibitor of thromboxane synthesis invivo and invitro

OKY-1581 is an effective inhibitor of thromboxane synthesis $\text{in}$$\text{vivo}$ and $\text{in}$$\text{vitro}$. The generation of thromboxane B₂ (TxB₂), prostaglandin E (PGE) and prostaglandin F (PGF) was measured following clotting and during platelet aggregation induced by collagen. The presence of OKY 1581 either $\text{in}$$\text{vivo}$ or $\text{in}$$\text{vitro}$ caused a reduction in TxB₂ generation during clotting and platelet aggregation with a concomitant increase in PGE and PGF. The effect could be observed two hours after oral or subcutaneous administration of 5 to 100 mg per rabbit and lasted for 24 to 48 hours. The reduction in TxB₂ was not accompanied by an inhibition of clotting or platelet aggregation. OKY-1581 appears to be a suitable agent for studying the role of TxB₂ in atherosclerosis.     

Anestrus in cycling beef heifers experimentally inoculated with Anaplasmamarginale

Normal estrous cycles were established for twenty beef heifers. Ten heifers were inoculated with blood from a known $\text{Anaplasma}$$\text{marginale}$ carrier. The inoculated heifers experienced anemia, anorexia, and positive $\text{Anaplasma}$$\text{marginale}$ complement-fixing antibody titers, and $\text{A}$. $\text{marginale}$ was observed on the erythrocytes while uninoculated control heifers remained normal. Further observation following inoculation revealed that five of ten inoculated heifers experienced anestrus while controls continued to cycle normally. Anestrus coincided with clinical signs of acute anaplasmosis. Normal estrus patterns returned following treatment and recovery. This study provides evidence that acute anaplasmosis in beef heifers may cause anestrus and therefore lead to reproductive inefficiency.     

Limulus anti-LPS factor: An anticoagulant which inhibits the endotoxin-mediated activation of Limulus coagulation system

Exposure of $\text{Limulus}$ amebocytes to bacterial endotoxins (lipopolysaccharides, LPS) results in the activation of the coagulation system, which consists of several protein components. During the separation of these components, a potent anticoagulant, named tentatively anti-LPS factor, which inhibits the endotoxin-mediated coagulation reaction, was found in both amebocytes from the hemolymphs of $\text{Tachypleus}\text{tridentatus}$ and $\text{Limulus}\text{polyphemus}$. The principle purified partially from $\text{Tachypleus}$ amebocyte lysate had a molecular weight less than 10,000, as judged with the ordinary gelfiltration experiment. It inhibited specifically the activation of factor B, which has recently been characterized to be a coagulation factor highly sensitive to LPS, but it did not inhibit the activities of the active factor B and the active clotting enzyme separated from the lysate. The inhibitory activity of anti-LPS factor disappeared almost completely by the treatments with pronase-P and subtilisin, suggesting its polypeptide-like substance, but it resisted to a boiling treatment. A possible site of the anticoagulant action on the $\text{Limulus}$ coagulation system was discussed.     

Regulation of argF mRNA synthesis,performed in vitro

The specific synthesis of $\text{arg}$F mRNA directed by the $\text{arg}$F gene carried on the specialized transducing bacteriophage $\text{λh80C}{}_1\text{857darg}$F, performed $\text{in vitro}$, is described with the use of an S180 extract from a strain carrying $\text{arg}$R^?. Synthesis of $\text{arg}$F mRNA is biphasic at approximately 7 minutes. The regulation of $\text{arg}$F mRNA synthesis by the specific arginine holorepressor present in an S180 extract prepared from a strain carrying the $\text{arg}$R⁺ allele is described.     

Cytochrome C553 from Desulfovibrio,vulgaris: Potentiometric characterization by optical and EPR studies

Cytochrome c₅₅₃ is a monohaemic c type cytochrome isolated from the sulfate reducing bacteria $\text{Desulfovibrio}$,$\text{vulgaris}$. Its midpoint potential value, determined by optical, EPR and polarographic studies is significantly lower than the midpoint potentials reported for other monohaemic cytochromes c (+ 10 mV instead of + 290 mV). In an attempt to study correlations between amino acid sequence, haem iron coordination and haem exposure in cytochromes c, cytochrome c₅₅₃ is compared with mitochondrial and bacterial c type cytochromes.     

Effect of removing the zona pellucida on development of hamster and bovine embryos invitro and invivo

Uterine stage embryos collected from the hamster (8-cell) and cow (morula, early blastocyst) were monitored for development $\text{in}$$\text{vitro}$ (embryo culture) and $\text{in}$$\text{vivo}$ (embryo transfer) following premature removal of the zona pellucida.Removal of the zona pellucida did not significantly affect $\text{in}$$\text{vitro}$ development to the blastocyst stage of (1) 8-cell hamster embryos (zonae removed by a combined enzymic-mechanical procedure), (2) bovine morulae (zonae removed by mechanical means only) (3) early bovine blastocysts (zonae removed by the enzymic-mechanical technique).Zona-free hamster embryos formed significantly fewer viable fetuses than did zona-intact embryos. The lower incidence of fetal development observed following transfer of zona-free 8-cell hamster embryos may have resulted in part from the formation of chimeras by fusion of these embryos $\text{in}$$\text{utero}$. Such fusion was observed to occur $\text{in}$$\text{vitro}$ between zona-free embryos placed in close proximity. The proportion of pregnancies resulting from transfer of bovine blastocysts cultured from zona-free morulae was similar to that of zona-intact embryos.In this study we have demonstrated that (1) enzymic and mechanical procedures used to remove zonae pellucidae from uterine-stage hamster and bovine embryos do not adversely affect subsequent development of these embryos $\text{in}$$\text{vitro}$ and $\text{in}$$\text{vivo}$ and (2) zonae pellucidae are not required for normal development of these embryos. These findings have implications for microsurgery of mammalian embryos and for embryo transfer.     

Inefficiency of the stringent response in the fungus Mucor

Removal of a required amino acid from the growth medium or addition of cycloheximide caused an immediate stoppage of growth and protein synthesis in the fungus $\text{Mucor}\text{racemosus}$. However, RNA synthesis persisted for several hours at rates that only gradually decreased under the same circumstances. An analysis of the major classes of RNA synthesized during the first hour of treatment showed that cycloheximide preferentially inhibited rRNA synthesis, whereas amino acid starvation slowed synthesis of all RNA species uniformly. Neither treatment affected the percentage of mRNA synthesized. The partial and delayed effects of amino acid starvation and cycloheximide treatment on RNA synthesis reported here suggest the absence of or the gross inefficiency of a classical stringent response in $\text{M.}\text{racemosus}$.     

Cloning and expression in Streptomyces lividans of a paromomycin phosphotransferase from Streptomyces rimosusforma paromomycinus

The paromomycin producing organism $\text{Streptomyces}$$\text{rimosus}$$\text{forma paromomycinus}$ is resistant to this antibiotic and contains a phosphotransferase which inactivates paromomycin. The gene encoding this enzyme has been inserted in the $\text{Streptomyces}$ vector pIJ702 and then cloned in $\text{Streptomyces}$$\text{lividans}$, selecting for paromomycin-resistance. Three plasmids have been isolated and one of them, pMJ1, contains a 2.2 kb insert with a single HindIII restriction site. Insertion of foreign DNA in this site blocks the expression of the phosphotransferase enzyme indicating that it is within the cloned gene. These findings provide a new dominant selective marker for $\text{Streptomyces}$ cloning vectors with the versatility of insertional inactivation.     

Primary structure of heat-stable enterotoxin produced by Yersinia enterocolitica

A heat-stable enterotoxin was isolated and purified from the culture supernatant of $\text{Yersinia enterocolitica}$ by reversed-phase high-performance liquid chromatography. The amino acid sequence of the purified toxin was determined to be as follows: Gln-Ala-Cys(X)-Asp-Pro-Pro-Ser-Pro-Pro-Ala-Glu-Val-Ser-Ser-Asp-Trp-Asp-Cys-Cys-Asp-Val-Cys-Cys-Asn-Pro-Ala-Cys-Ala-Gly-Cys (X: not determined). The C-terminal sequence containing 6 half-cystine residues was highly homologous to that of heat-stable enterotoxin of enterotoxigenic $\text{Escherichia coli.}$     

Membrane fluidity and drug metabolism in liver microsomes of lean, obob and dbdb mice

The thermally-induced changes of a cytochrome P-450 dependent activity (ethoxycoumarin-O-deethylase) and of the fluorescence polarization of diphenylhexatriene were compared in microsomes from lean, $\text{ob}\text{ob}$ and $\text{db}\text{db}$ mice. In lean mice, biphasic plots were obtained with break points in the same range of temperature by both methods, whereas, in $\text{ob}\text{ob}$ and $\text{db}\text{db}$ mice, no discontinuities were observed. These results may be related to a modified fatty acid composition of microsomal membranes in mutant mice. They exemplify the influence of the lipid environment on the monooxygenase system as also shown by the modified binding constants of cytochrome P-450 towards type II substrates in $\text{db}\text{db}$ mice.     

Studies on the red oxidase (cytochrome o) of Azotobacter vinelandii

In an attempt to isolate and to study the electron transport system of $\text{Azotobacter vinelandii}$, we have isolated and purified a membrane-bound cytochrome $\text{o}$. The cytochrome $\text{o}$, purified as a detergent (Triton X-100) and hemoprotein complex, contained 1.6 nmoles heme per mg of protein. Cold-temperature spectrum showed that no other cytochrome was associated with the purified preparation, and electrophoresis revealed that only one type of hemoprotein was obtained. The purified cytochrome $\text{o}$ reacted with both carbon monoxide and cyanide readily. Only in the reduced form did it combine with carbon monoxide, whereas the oxidized form reacted with cyanide. An “oxygenated” form of the cytochrome $\text{o}$ was demonstrated to be spectrally distinguishable from both the oxidized and the reduced forms.     

Ephedrine reduces weight of viable yellow obese mice (Avy/a)

Ephedrine administered subcutaneously or in the diet reduces the weight of viable yellow obese mice ($\text{A}{}^{\mathrm{vy}}$/$\text{a}$) and normal mice. The compound has some appetite-suppression activity; however, reduced food consumption could not account for all of the weight loss. Ephedrine did not affect lipogenesis or lipolysis acutely. The major portion of the weight loss was due to the loss of triacylglycerol. The rectal temperature of long-term treated $\text{A}{}^{\mathrm{vy}}$/$\text{a}$ mice was elevated suggesting that ephedrine may alter energy metabolism.     

Disaggregation of elongation factor 1 by extracts of Artemiasalina

Extracts of 40 hr $\text{Artemia}$$\text{salina}$ nauplii can convert a heavy form of elongation factor 1 (EF-1_H) to a light species (EF-1_L). The data indicate that a protease in the extracts is responsible for this reaction, and these findings may explain the observation that extracts from $\text{Artemia}$$\text{salina}$ nauplii have only EF-1_L whereas before hatching of the $\text{Artemia}$$\text{salina}$ embryos EF-1_H is the predominant species (Slobin and M?ller [1975] Nature 258, 452–454).     

Effect of Brucellaabortus infection on spermatogenesis in three Zebu bulls (Bosindicus). A case report

This case report addresses the occurrence of Brucellosis and its effect on the cattle in developing countries. Three Zebu bulls ($\text{Bos}$$\text{indicus}$) are presented and the clinical and pathologic signs are described. Conception rates declined following an abortion storm in one herd and without prior abortions in another herd. Semen collected by electro-ejaculation was found to be azoospermic or with very few spermatozoa. $\text{B. abortus}$ was isolated from seminal vesicles, testes and epididymides. Organs affected and showing microscopic lesions were testes, epididymides and seminal vesicles. The latter were not consistently affected. None of the bulls showed impairment of libido or breeding capacity.     

The bioadhesive of Mytilus byssus: A protein containing L-DOPA

L-DOPA was identified in hydrolysates of $\text{Mytilus}$ byssal adhesive discs and is present at about $\text{10}\text{res}\text{1000}$. The compound was isolated and purified by ion exchange on cellulose phosphate and Biogel P-2 gel filtration. Identity with standard DOPA was demonstrated using thin-layer chromatography, the effect of pH on UV absorbance, fluorescence spectrophotometry, amino acid analysis, and the preparation of ethylenediamine derivatives. Contrary to earlier reports, dityrosine was not detected. A sodium dodecylsulfate-insoluble protein containing $\text{48}\text{res}\text{1000}$ of DOPA was isolated from the gland that secretes the disc adhesive. This protein is presumed to be a precursor of the adhesive.     

The influence of dna A and dna C mutations on the initiation of plasmid DNA replication

The dependence of the replication of several plasmids on the chromosome-determined initiation products, $\text{dna}$ A and $\text{dna}$ C, has been studied. The initiation of the replication of $\text{Col}$ E₁ DNA requires the chromosomal $\text{dna}$ A product. In contrast two de-repressed transfer factors ($\text{R 1 drd 16}$ and $\text{Hly}$₁₅₂) seem to determine a corresponding plasmid-specific factor. The $\text{dna}$ C-product is necessary for the ordered initation of all plasmids studied. The addition of low concentrations of chloramphenicol leads to a relaxed replication of $\text{Col}$ E₁ DNA at the restrictive temperature in $\text{dna}$ A-mutants, but not in $\text{dna}$ C-mutants.     

Fluorescence properties of chlorophyll a and b monomolecular films at the air-water interface

The fluorescence properties of chlorophyll $\text{a}$ and $\text{b}$ monomolecular films at the air-water interface were measured by a high sensitivity fluorophotometer using the photon-counting method. The fluorescence intensity of chlorophyll molecules in monomolecular films in the absence of any diluents did not decrease simply with the mean distance of chlorophyll molecules. Over the range of the mean distances from 27 to 21 Å, three fluorescence components (peaks at 685, 695 and 715 nm) of chlorophyll $\text{a}$ were observed. In the case of chlorophyll $\text{b}$, two fluorescence components (peaks at 667 and 685 nm) were observed over the range of the mean distances from 34 to 24 Å. When the mean distance was 18 Å, the short wavelength component of chlorophyll $\text{b}$ disappeared, and only the long wavelength component was observed.