S-Adenosylmethionine synthetase isozyme patterns from rat hepatoma induced by N-2-fluorenylacetamide

Isozyme patterns of $\text{S}$-adenosylmethionine synthetase have been measured with and without dimethylsulfoxide in hepatoma of rats induced by $\text{N}$-2-fluorenylacetamide. The isozymes of α- and β-types existing in normal rat liver gradually decreased with the progress of hepatocarcinoma, and the kidney type γ-enzyme appears along with disappearance of both α- and β-enzymes. The liver from rat fetus contains a greater part of γ-type enzyme.     

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.     

Isolation and preliminary characterization of 1-O-Octadec-cis-11-enyl glycerol from Paramecium phospholipids

1-O-Octadec-$\text{cis}$-11-enyl glycerol, paramecyl alcohol, was isolated from $\text{Paramecium}\text{tetraurelia}$ and $\text{P.}\text{caudatum}$ phospholipids. This isomer of 1-O-octadec-9-enyl glycerol, selachyl alcohol, had not been previously reported as a component of naturally-occurring phospholipids. The preliminary characterization of the structure of this compound was determined by 1) gas chromatography of the parent compound as well as the products following hydrogenation, ozonolysis and oxidation, 2) mass spectrometry of the parent compound and an oxidation product, 3) infrared spectroscopy, and 4) proton magnetic resonance.     

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.     

The synthesis of 13-cis-dl-erythro-15, 16-dihydroxyprostaglandins

Both pairs of $\text{dl}$-ll-desoxy- and $\text{dl}$-13-$\text{cis}$-$\text{erythro}$-15, 16-dihydroxyprostaglandins have been synthesized via 1,4-conjugate additions of an appropriately functionalized $\text{cis}$-vinyl cuprate to the requisite cyclopentenone. These prostaglandin analogs are considerably less potent than PGE₂ as gastric secretion inhibitors or as bronchodilators.     

Guanylate cyclase from Dictyosteliumdiscoideum

Guanylate cyclase from crude homogenates of vegetative $\text{Dictyostelium}$$\text{discoideum}$ has been characterized. It has a pH optimum of 8.0, temperature optimum of 25°C and requires 1 mM dithiothreitol for optimal activity. It strongly prefers Mn⁺⁺ to Mg⁺⁺ as divalent cation, requires Mn⁺⁺ in excess of GTP for detectable activity, and is inhibited by high Mn⁺⁺ concentrations. It has an apparent Km for GTP of approximately 517 μM at 1 mM excess Mn⁺⁺.The specific activity of guanylate cyclase in vegetative homogenates is 50–80 pmoles cGMP formed/min/mg protein. Most of the vegetative activity is found in the supernatant of a 100,000 x g spin (S100). The enzyme is relatively unstable. It loses 40% of its activity after 3 hours storage on ice. Enzyme activity was measured from cells that had been shaken in phosphate buffer for various times. It was found that the specific activity changed little for at least 8 hours. Cyclic AMP at 10^?4 M did not affect the guanylate cyclase activity from crude homogenates of vegetative or 6 hour phosphate-shaken cells.     

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 $\text{A}$.     

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.     

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.     

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.     

Synthesis of d1-4,5,6-trinor-3,7-inter-m-phenylene-3-oxaprostaglandins including one which inhibits platelet aggregation

The synthesis of $\text{d1}$-4,5,6-trinor-3,7-inter-$\text{m}$-phenylene-3-oxaprostaglandins oxaprostaglandins of the E₁ and F₁α series⁷ from 6-endo-(1-heptenyl)-bicyclo[3:1:0]hexan-3-one (III), is described. Preliminary biological screening data for gerbil colon smooth muscle stimulation, rat blood pressure and substrate specificity toward 15-hydroxyprostaglandin dehydrogenase is presented. Platelet function studies, both $\text{in vitro}$ and $\text{in vivo}$ of $\text{d1}$-4,5,6-trinor-3,7-inter-$\text{m}$-phenylene-3-oxa-PGE₁, methyl ester (VIII) are presented.     

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.     

Denovo synthesis of prolactin by human decidua

Relatively large amounts of immunoreactive prolactin were measured in homogenates of human decidual tissue obtained immediately after delivery of normal term pregnancies. In order to study the release and possible synthesis of prolactin by this tissue, explants of decidua were incubated for 24 hours at 37°C in oxygenated Gey's buffer containing 20% fetal calf serum. When cycloheximide was added to the medium in concentrations sufficient to prevent $\text{in}$$\text{vitro}$ protein synthesis, 85–90% of the prolactin present in the tissue was released into the medium during the first 3 hours of incubation. No additional prolactin accumulated in either the medium or the tissue during the remainder of the incubation period. In the absence of cycloheximide, the prolactin concentration in the medium increased progressively during incubation, so that after 24 hours the total amount of hormone present in the tissue and medium was significantly greater than that in the tissue and medium prior to incubation (37.6 ± 9.6 ng/ml at 0 time vs 82.2 ± 7.7 ng/ml at 24 hours). When ³H-1-leucine (100 u Ci) was supplied during incubation, radioactive proteins were detected in the medium at 24 hr, 14–20% of which were specifically precipitated by antiserum to human pituitary prolactin. When aliquots of this medium were chromatographed on Sephadex G-100, 80–95% of the ³H-proteins precipitated by antiserum to pituitary prolactin eluted in the same position as did purified, iodinated pituitary prolactin. These data indicate that a species of prolactin which is identical to pituitary prolactin by the criteria of immunoprecipitation and gel chromatography is synthesized by human decidual tissue $\text{in}$$\text{vitro}$.     

Early steroid metabolism by chick blastoderm invitro

Yolk free blastoderms of chick embryo were incubated 3 or 22 hours with labeled pregnenolone, progesterone, 17-hydroxyprogesterone, dehydro-epiandrosterone, androstenedione, testosterone and estradiol-17β. Metabolites and unconverted substrates were found both in the incubation medium and in the cells. Enzymes responsible for identified conversions were: 17α-hydroxylase, 17-20-desmolase, Δ⁵3β- and 3α-hydroxysteroid dehydrogenase, 17β-hydroxysteroid dehydrogenase and 5α- and 5β-reductase. The results suggest that the steroid metabolizing enzyme activities found may reflect a more general ability of early embryonic cells.     

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.     

Bromobenzene and p-bromophenol toxicity and covalent binding invivo

A hepatotoxic dose of bromobenzene (3 mmoles/kg) decreases hepatic glutathione concentration in rats by approximately 80% within 5 hr following ip injection. A major bromobenzene metabolite, p-bromophenol at a similar dose did not significantly alter hepatic glutathione levels compared to controls. Twenty four hr after administration, serum glutamate pyruvate transaminase (SGPT) levels were significantly increased by bromobenzene but not by p-bromophenol. After ¹⁴C-bromobenzene administration, a significant amount of covalently bound radiolabel was detected in liver, kidney and small intestine. A small amount of covalently bound radiolabel was also detected in the lung. After a similar dose of ¹⁴C-bromophenol, covalently bound radiolabel was found in liver (62% of the amount detected with ¹⁴C-bromobenzene) and smaller amounts were detected in kidney, small intestine and lung. These data are consistent with the view that the hepatotoxity and glutathione depleting ability of bromobenzene are mediated mainly by bromobenzene-3, 4-oxide rather than by chemically reactive metabolites of p-bromophenol derived from bromobenzene. Covalently bound radiolabel from ¹⁴C-bromobenzene, however, may be derived from both bromobenzene-3, 4-oxide and the nontoxic reactive metabolites of p-bromophenol.     

Effects of experimental Trypanosomavivax on fertility of heifers

Six heifers were used in a series of experiments to study the effects of experimental $\text{Trypanosoma}$$\text{vivax}$ infection on bovine reproduction. Four three-year-old Zebu heifers were intravenously inoculated with T. vivax-strain Y58 — on days 14 and 16 of their estrous cycle and two control heifers in the same phase of estrus were not infected. All the heifers were bred in the research pens with a proven bull. The four infected heifers were bred at the first wave of parasitemia and the onset of pyrexia which characterised the infection. All the heifers were examined rectally 40 days after breeding. The four infected heifers were not pregnant but the two controls were. The infected heifers later became anestrous during the experimental period of more than five months. It is concluded that trypanosomiasis may contribute to high infertility rates in cattle kept in endemic areas.     

Extra components in kinetoplast DNA preparations from Crithidiafasciculata

Kinetoplast DNA from the order Kinetoplastidae (trypanosomatids) exists as large associations (molecular weight 4 × 10¹⁰), made up of about 104 small, probably circular, molecules, commonly known as ‘minicircles’. These minicircles were originally thought to be identical in base composition, suggesting that the coding capacity of kinetoplast DNA is very restricted. However, linear molecules have also been observed in preparations of kinetoplast DNA, which, if they contain unique sequences, could represent additional genetic information. This linear DNA has been assumed to be derived from the kinetoplast, but the possibility of it being nuclear contamination has not been definitely ruled out. Work presented in this paper demonstrates that nuclear DNA contamination may indeed be present in kinetoplast DNA prepared by a commonly used method.