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Keyhole gas tungsten arc welding (GTAW) is a relatively new variant used for fabrication of pressure equipment where up to 10-mm-thick material can be autogenously welded in one pass. As the shielding gas used for keyhole mode is typically Ar + 5% H2, the suitability of this method for welding of duplex stainless steels has been investigated. Duplex UNS S31803 and superduplex UNS S32750 schedule 40 seamless pipe was welded using a closed square butt joint configuration. Shielding gas compositions were applied with increasing nitrogen content in argon or argon-hydrogen mixtures. An investigation of the completed welds included examinations of the microstructure, corrosion and mechanical properties of the weld metal. All shielding gases resulted in high-quality welds free from defects, showed high strength and excellent corrosion resistance. Hydrogen additions increased the weld metal nitrogen loss and resulted in lower austenite formation. Ar + 5% H2showed up to 20 vol.% less austenite than the gas types containing nitrogen and also showed the lowest impact toughness. At least 2% nitrogen would be recommended for optimizing the phase balance and impact toughness. Taking all aspects into account, Ar + 2% N2is the preferred shielding gas for welding duplex and superduplex with the keyhole GTAW process.

A careful investigation of cultures of Myrothecium verrucaria has shown that this fungus produces all four roridin E isomers (3a−d), diastereomeric at the C-6‘ and C-13‘ centers. The stereochemistries at these centers were established by a combination of X-ray crystallographic analysis, NMR spectroscopy, and chemical transformations. NMR data from these and other macrocyclic trichothecenes allows for the assignment of configurations at the C-6‘ and C-13‘ centers for most of these compounds, the exceptions being those congeners having a C-4‘ ketone group in the macrolide ring.

From several presumably pure cultures of Thiobacillus ferrooxidans, we isolated a pair of stable phenotypes. One was a strict autotroph utilizing sulfur or ferrous iron as the energy source and unable to utilize glucose; the other phenotype was an acidophilic obligate heterotroph capable of utilizing glucose but not sulfur or ferrous iron. The acidophilic obligate heterotroph not only was encountered in cultures of T. ferrooxidans, but also was isolated with glucose-mineral salts medium, pH 2.0, directly from coal refuse. By means of deoxyribonucleic acid homology, we have demonstrated that the acidophilic heterotrophs are of a different genotype from T. ferrooxidans, not closely related to this species; we have shown also that the acidophilic obligate heterotrophs, regardless of their source of isolation, are related to each other. Therefore, cultures of T. ferrooxidans reported capable of utilizing organic compounds should be carefully examined for contamination. The acidophilic heterotrophs isolated by us are different from T. acidophilis, which is also associated with T. ferrooxidans but is facultative, utilizing both glucose and elemental sulfur as energy sources. Since they are so common and tenacious in T. ferrooxidans cultures, the heterotrophs must be associated with T. ferrooxidans in the natural habitat.

Twenty seven isolates of Stachybotrys chartarum, S. albipes, S. kampalensis and S. microspora from Egypt and Eastern Europe were tested for production of macrocyclic trichothecenes. Twenty of the 27 isolates, grown on rice seeds, were toxic to brine shrimp larvae. Based on TLC and HPLC analyses, 5 macrocyclic trichothecenes (verrucarin J, roridin E, satratoxins F, G & H) as well as trichoverrols were identified. When grown in liquid culture on rice extract medium, only 3 isolates were toxic and produced verrucarin J, roridin E and satratoxins G & H. Extracts from mycelial mats were more toxic than culture filterates of two isolates grown on rice extract and both contained the same macrocyclic trichothecenes (285.5 mg/4 L), in addition to trichoverrols A & B (31 mg/4 L) found in mycelial mats only. When grown on 3% sucrose Czapek's medium supplemented with peptone and yeast extract (still cultures), all isolates were non-toxic to brine shrimp and no trichothecenes could be detected in the extracts.

The ability of two plant-produced macrocyclic trichothecenes (baccharinoid B4 and roridin E) to induce callus growth of two trichothecene-producing Baccharis species (B. coridifolia and B. megapotamica) and two nontrichothecene-producing species (B. halimifolia and B. neglecta) was investigated. Roridin E had no effect in the induction of callus of B. coridifolia, a roridin-producing plant, but induced callus of nonroridin-producing plants (B. megapotamica, B. halimifolia, and B. neglecta). Baccharinoid B4 stimulated callus growth of B. megapotamica, a baccharinoid-producing plant, and inhibited growth of B. coridifolia, B. halimifolia, and B. neglecta callus tissues. The ability of roridin E to induce callus was most effective at concentrations of 10-8 and 10-6 M and when synergistically coupled with auxin, 2,4-dichlorophenoxyacetic acid (2,4-D). The ability of baccharinoid B4 to stimulate callus growth appeared to increase with increased concentration in the culture medium. Analysis of callus cultures grown in medium amended with roridin E showed that B4, roridin E, and 8ß-hydroxyroridin E and verrucarols were formed in the tissues but not in the medium. The results of this study indicated that while the callus-inducing ability of roridin E seemed to be nonspecies-specific in nature, the ability of B4 to stimulate callus was a highly species-specific phenomena. Callus-inducing activity of roridin E may depend on the capacity of plant species to transform exogenous roridin E into baccharinoids or other macrocyclic trichothecene derivatives.

Traditional oak wood storage vats used to ferment and mature commercial fermented alcoholic cider are being phased-out and replaced by stainless steel vessels. Each wood vat, however, despite hot-wash cleaning between cider batches, is shown to retain an extensive and distinctive microflora of yeast and bacteria. These micro-organisms could act as a reservoir of both beneficial and spoilage organisms. Over a period of 10 weeks, the progressive microbial penetration and colonization of blocks of vat wood suspended in maturing commercial cider is demonstrated by use of scanning electron microscopy. Within 2 weeks cell penetration was to a depth of 1.2 cm. Lactic acid bacteria originating from wood are also shown to be capable of sponsoring malo-lactic fermentation of freshly fermented cider and hence positively contributing to changes in the organoleptic profile of a stored beverage.

From October 1981 to September 1984, the authors conducted a three-year longitudinal study of diarrhea among infants and toddlers attending day care centers in Maricopa County, Arizona. In the third year of study, they evaluated the effects on diarrhea rates of staff training without external monitoring and of active surveillance conducted throughout the study. From 21 study day care centers, they randomly selected 10 ("intervention day care centers") to receive staff training in procedures to reduce transmission of infectious diarrhea. Continuing active surveillance in the 10 intervention and 11 control day care centers found no difference between diarrhea rates in intervention day care centers in the pre- and posttraining years and no difference between diarrhea rates in the two groups of centers either before or after the training intervention. Biweekly family-based surveys during the two months after training also demonstrated no difference between infant-toddler diarrhea rates in intervention and control day care centers. These surveys found the 21 study day care centers to have significantly higher diarrhea rates than did day care homes or households not using day care, but significantly lower rates than day care centers not included in the active surveillance. Continuous surveillance without training was associated with a significant decrease in diarrheal illness during the course of longitudinal study. One-time staff training without subsequent monitoring did not result in additional decreases and did not lower day care center diarrhea rates to the levels observed in day care homes and households not using day care.

Canine cardiac sarcoplasmic reticulum vesicles have been labeled by covalent cross-linking to membrane-bound 125I-calmodulin with dithiobis(succinimidyl propionate). Electrophoretic analysis in sodium dodecyl sulfate demonstrated a 125I-containing major product of Mr = 40,000, and a minor component of Mr = 120,000. This latter component probably represents a 1:1 complex between the 100,000-dalton Ca2+-ATPase protein and 125I-calmodulin. When cross-linked samples, solubilized in sodium dodecyl sulfate, were boiled for 2 min, the radioactivity associated with the 40,000-dalton component decreased while that associated with components of 26,000 and 28,000 daltons increased. When these boiled samples were stored at -70 degrees C for 1 week, the radioactivity associated with the 26,000- and 28,000-dalton components decreased whereas that associated with the 40,000-dalton component was increased. This suggests that the 40,000-dalton component represents a 1:1 cross-link between the 23,000-dalton form of phospholamban and 125I-calmodulin. The 26,000- and 28,000-dalton cross-linked components probably represent 1:1 cross-links between 125I-calmodulin and the 8,000- and 11,000-dalton subunits, respectively, of phospholamban. A 32P-containing, 40,000-dalton component was formed when dithiobis(succinimidyl propionate) was added to sarcoplasmic reticulum vesicles, phosphorylated in the presence of [gamma-32P]ATP and 3 microM calmodulin. This confirms that the 40,000-dalton affinity-labeled component is a 1:1 cross-link between phospholamban and calmodulin. We propose that phospholamban is the endogenous receptor for calmodulin in cardiac sarcoplasmic reticulum membranes. However, it is unlikely that phospholamban is the endogenous calmodulin-dependent protein kinase in this membrane.

Phospholamban, a 23,000-dalton phosphoprotein present in cardiac muscle sarcoplasmic reticulum vesicles is quantitatively dissociated into three smaller sized phosphorylated components of 11,000, 15,000, and 20,000 daltons when sarcoplasmic reticulum, solubilized in 1% (w/v) sodium dodecyl sulfate and 1 mM MgCl2, is heated at 71 degrees C or greater for 2 min. This dissociation is inhibited by Mg2+ (50% at approximately 5 mM). The 23,000-dalton phosphoprotein reformed from the 11,000-, 15,000-, and 20,000-dalton phosphorylated components when phosphorylated sarcoplasmic reticulum that had been boiled in 1% sodium dodecyl sulfate and 1 MM MgCl2 was stored for 1 week at -70 degrees C. We propose that the 23,000-dalton phosphorylated protein is a trimer, composed of three subunits with molecular mass of 11,000, 8,000, and 4,000 daltons. In this model, only the 11,000-dalton subunit would be phosphorylated. The partial dissociation of the 23,000-dalton phosphorylated protein would result in the formation of the 19,000 (11,000 + 8,000)-dalton or the 15,000 (11,000 + 4,000)- dalton phosphorylated components. Full dissociation of the 23,000-dalton phosphorylated protein would result in the formation of the 11,000-dalton phosphorylated component.

Condensation nucleus (CN) concentrations have been measured at Mawson (67.6°S, 62.9°E) since mid 1981. Weekly median concentrations have an annual cycle with a maximum of around 300 to 400 cm-3 in summer and a minimum of a few tens of particles per cm-3 in winter. In this respect Mawson behaves very much like an Antarctic continental location. Preliminary measurements of the size distribution of CN particles taken over a nine month period suggest a seasonal change in typical particle radius from around 0.01 µm in winter to around 0.04 µm in summer. Diurnal variation in the CN concentration is generally very weak and does not show any systematic relation to the pronounced diurnal variation in wind-speed at Mawson.

Monoclonal antibody (mAb) 1604 is directed against a cell surface antigen of Myxococcus xanthus. Purified antibody 1604 inhibited development of M. xanthus under conditions of submerged culture procedure otherwise leading to fruiting body formation. Intact molecules of mAb 1604, as well as its Fab fragments, inhibited developmental aggregation, autolysis, fruiting body formation, and sporulation. The addition of relatively small amounts of antibody every 4 hr was much more effective than a single large dose given at the onset of development. The inhibitory action of mAb 1604 on development was reversible after prolonged incubation of the antibody with cells; this was probably due to proteolytic degradation of the antibody. The effect of mAb 1604 on submerged bacterial development was neutralized by affinity-purified 1604 cell surface antigen. Another antibody, mAb 2788, directed against an M. xanthus cell surface antigen, did not block development. These data suggest that 1604 cell surface antigens is involved in contact-mediated cell interactions in M. xanthus.

A rapid, inexpensive bioassay to detect Myrothecium spp.-produced macrocyclic trichothecenes was developed. Media containing Myrothecium isolates were inoculated with Chlorella vulgaris, Ustilago maydis and Trichoderma viride. Based on width of the inhibition zone, isolates could be classified as highly toxigenic, non-toxigenic and intermediate. Whereas, C. vulgaris and U. maydis showed significant differences in their response to toxigenic and non-toxigenic isolates, T. viride did not. Production of roridins and verrucarins by the toxigenic isolates (by bioassay) was confirmed by thin layer chromatography and high performance liquid chromatography. This bioassay system, combined with confirmation chemical analyses, increases our ability to detect toxigenic fungal isolates.

An early event in septic shock is the activation of macrophages by a complex consisting of lipopolysaccharide (LPS), LPS-binding protein (LBP), and the cell surface antigen CD14. The complexes that form between [3H]ReLPS (ReLPS is deep-rough-chemotype hexacyl LPS from E. coli D31m4), soluble CD14 (sCD14), and LBP were analyzed by two independent methods, native (nondenaturing) gel electrophoresis and size-exclusion high-performance liquid chromatography (HPLC). This is the first reported use of HPLC to purify and study LPS-protein complexes. The binding of [3H]ReLPS to LBP and sCD14 was inhibited by preincubation with diphosphoryl lipid A from Rhodobacter sphaeroides (RsDPLA), a potent LPS antagonist. In addition, [3H]ReLPS bound to LBP and to a truncated form of sCD14 [sCD14(1-152)] that contained the LPS binding domain. Binding to both proteins was blocked by RsDPLA. Thus, RsDPLA competes in a 1:1 ratio for the same or nearby binding sites on ReLPS complexes. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of aggregated ReLPS eluting from the HPLC indicated that only LBP, not sCD14, was bound to the aggregated ReLPS. This finding supports the binary model of LPS complex formation with LBP and sCD14.

The transcription factor Sp1 plays a crucial role in the monocyte-specific expression of CD14, a binding site (or putative receptor) for lipopolysaccharide (LPS) complexes with LPS-binding protein (LBP). By using RAW 264.7 macrophages treated with spectrally pure deep-rough-chemotype hexa-acyl LPS from Escherichia coli D31m4, three inhibitors were found to block the binding activity of transcription factor Sp1, as measured by electrophoretic mobility shift assays. These inhibitors were diphosphoryl lipid A from Rhodobacter sphaeroides (10 microg/ml); the isoquinoline-sulfonamide H-8 (10 and 100 microM), which is thought to be a cGMP-dependent protein kinase inhibitor; and the anti-inflammatory agent dexamethasone (10 microM).

High irradiance during treatment of mung bean cuttings favours root formation in response to supplied auxin, whether the latter is IAA or IBA. On the other hand it is inhibitory towards root formation in the absence of supplied auxin. Light promotes the uptake of14C-IAA into cuttings and its upward movement into the leaves. When14C-IAA is applied to leaves of cuttings high irradiance favours movement of radioactivity into the epicotyl and hypocotyl. This movement is also enhanced by concomitant supply of IBA to the base of the cuttings. The irradiance under which stock plants are raised also affects the extent of root formation on cuttings. When cuttings are held in darkness without a supply of exogenous auxin they root best if prepared from seedlings raised under high irradiance. However, transport of14C-IAA out of leaves of cuttings is favoured when cuttings are prepared from seedlings grown under low irradiance. These observations are discussed in relation to auxin transport, photodestruction and, possibly, metabolism.

Adventitious root formation in stem cuttings of mung bean was enhanced by ethrel, which had an additive effect when employed simultaneously with indolebutyric acid (IBA). Abscisic acid (ABA) did not influence the number of roots per cutting whereas gibberellic acid (GA3) and kinetin were without effect on rooting at lower concentrations but were inhibitory at higher concentrations. Nevertheless, all three of these chemicals showed synergistic interactions with IBA and/or indol-3-ylacetic acid (IAA) and thereby significantly promoted root formation. A localised application of morphactin to the epicotyl of cuttings totally inhibited root production irrespective of which of the foregoing growth regulators were suppliedviathe hypocotyl. Morphactin application also prevented root formation in cuttings treated with vitamin D2. The various growth regulators employed had differing effects on growth of roots but there was no simple relationship between their effects on root formation and subsequent root growth.

Trichoverroids, which lie along the biosynthetic path between the simple and the macrocyclic trichothecenes, have been characterized previously as sets of diastereomers that have the S-configuration at C-6‘ and are epimeric at C-7‘. An isolate of Myrothecium verrucaria (ATCC 20540), which is the only species of Myrothecium reported to produce the macrocyclic trichothecene isororidin E (3a), produces trichoverrols (1) and trichoverrins (2) that are epimeric at C-7‘ but that have R-configurations at the C-6‘ centers. Also reported are several additional naturally occurring C6‘R-series trichoverroids that have varied structural modifications, including several E,Z-isomers 7−9, 9β,10β-epoxides 11a and b, 12,13-deoxyisotrichoverrin B (10), and 8α-hydroxyisotrichoverrin A (12).

The inhibition of development of Myxococcus xanthus by monoclonal antibody (MAb) 1604 has been further investigated with two MAbs produced against the affinity-purified cell surface antigen (CSA) 1604. Both of these second-generation MAbs, 4070 and 4054, reacted with the same band at 150 kilodaltons (kDa) on Western immunoblots of lysed and reduced cells. This band was also identified by MAb 1604. However, the affinity-purified CSA was a complex of the two proteins (51 and 23 kDa) and lipopolysaccharide (LPS) that the 150-kDa material comprised. One of the three MAbs, 4070, reacted with LPS on Western immunoblots. Another MAb, 4054, reacted with the 23-kDa protein, and MAb 1604 reacted with the 51-kDa protein found in the CSA complex. Competitive binding studies verified that MAbs 4054 and 1604 identified different epitopes, and MAb 4070 probably reacted with a third epitope of the CSA 1604 complex. MAb 4054 blocked development, although not as thoroughly as MAb 1604 did, when added at 60 micrograms/ml to cells undergoing submerged development. In contrast, MAb 4070 prevented sporulation in submerged development and induced the cells to reaggregate in rings around the initial aggregation centers. A mutant strain of M. xanthus that is deficient in the epitope for MAb 1604 retained the epitope for MAb 4054. The affinity-purified antigen 1604, when added to cells at greater than or equal to 550 ng/ml, altered the appearance of the fruiting bodies and at higher concentrations prevented fruiting body formation. The CSA 1604 moiety responsible for this inhibitory effect is apparently a peptide constituent and not the LPS.

A cell surface antigen complex from Zwittergent-solubilized Myxococcus xanthus has been purified by immunoaffinity chromatography with monoclonal antibody (MAb) 1604 and by subsequent gel filtration. We propose that the cell surface antigen (CSA) 1604 complex participates in intercellular interactions. The apparent total molecular mass of the CSA 1604 complex is 200 kilodaltons (kDa), as determined by gel filtration and by electrophoresis and Western immunoblot probing with MAb 1604. The antigen epitope recognized by MAb 1604 is on a 51-kDa polypeptide. The CSA complex also contains 14% neutral carbohydrate and a 23-kDa polypeptide that lacks the 1604 epitope. The carbohydrate is most likely part of a lipopolysaccharide (LPS) associated with the CSA, because an MAb recognizing an O antigen epitope from the LPS of M. xanthus also reacted with CSA 1604 on Western immunoblots. Thus, the 200-kDa CSA complex consists of 97 +/- 6 kDa of protein and many associated LPS molecules. The LPS evidently produces the multiplicity of bands observed on Western immunoblots between 100 and 200 kDa. The association with LPS may contribute to the negative charge of the CSA 1604 complex, which has a pI of 4.3. The CSA was clustered on the surface of intact M. xanthus cells after labeling with MAb 1604 and immunogold. Furthermore, fractionation studies indicated that cells grown on a plastic surface had 50% of their total CSA 1604 in the cytosol, 39% in the membrane fraction, and 8% in the periplasm. Saturable binding studies with 125I-MAb 1604 indicated that there were 2,400 CSA 1604 sites per cell. The Kd for MAb 1604 binding to the cell was 9 nM.

Rhizobium loti NZP2037 and NZP2213, each cured of its single large indigenous plasmid, formed effective nodules on Lotus spp., suggesting that the symbiotic genes are carried on the chromosome of these strains. By using pSUP1011 as a vector for introducing transposon Tn5 into R. loti NZP2037, symbiotic mutants blocked in hair curling (Hac), nodule initiation (Noi), bacterial release (Bar), and nitrogen fixation (Nif/Cof) on Lotus pedunculatus were isolated. Cosmids complementing the Hac, Noi, and Bar mutants were isolated from a pLAFR1 gene library of NZP2037 DNA by in planta complementation and found to contain EcoRI fragments of identical sizes to those into which Tn5 had inserted in the mutants. The cosmids that complemented the mutants of these phenotypic classes did not share common fragments, nor did cosmids that complemented four mutants within the Noi class, suggesting that these symbiotically important regions are not tightly linked on the R. loti chromosome.

Macrocyclic trichothecenes are a class of mycotoxins, some of which exhibit substantial antileukemic properties. These compounds vary in their toxicity by approximately 100 fold and are suspected immunotoxins. We studied 11 of these mycotoxins: roritoxin B, myrotoxin B, roridin A, verrucarin A, 16-hydroxyverrucarin A, verrucarin J, baccharinoid B12, roridin D, roridin E, baccharinoid B4 and baccharinoid B5 for their immunotoxicity in CD-1 mice. An equitoxic dose was prepared in 1% DMSO in saline and administered i.p. at half the LD50. Organ weights, WBC, RBC, differentials of blood cell counts, blastogenesis of splenic lymphocytes in response to concanavalin A (Con A), lipopolysaccharide (LPS), phytohemagglutinin (PHA) and pokeweed mitogen (PWM), and mixed lymphocyte reaction (MLR) were studied on day 4 after administration of each mycotoxin. Organ weights showed significant differences between the controls and the baccharinoids with a decrease in spleen weight in baccharinoid B12 and an increased liver weight in B4 and B5 treated animals. Administration of myrotoxin B, roridin A, verrucarin J and roridin E had total WBC counts statistically different from controls, while mice administered myrotoxin B showed a decrease in numbers of RBC. Differentials of WBC were unremarkable regardless of the mycotoxin. Roritoxin B and baccharinoid B5 increased Con A stimulation of splenic lymphocytes. Roridin A and baccharinoid B12 increased LPS stimulation of splenic lymphocytes while baccharinoid B5 decreased the LPS response. Stimulation of splenic lymphocytes with PHA was significantly increased by roridin A and baccharinoid B5. Stimulation of splenic lymphocytes with PWM was not altered significantly by any mycotoxin. The baccharinoids B12 and B4 showed significant increases of T cell proliferation in the MLR. Antibody production evaluated by the sheep red blood cell (SRBC) hemolytic-plaque assay indicated none of the mycotoxins gave a statistically different response. However, anti-SRBC antibodies evaluated by the enzyme-linked immunosorbent assay, were significantly decreased in mice administered roridin D and E and baccharinoid B5.

Two criteria suggest that most of the proteinase of Streptococcus lactisis localized in the cell wall. (i) Intact cells possess proteinase activity when incubated with a high-molecular-weight substrate. (ii) Most of the cell-bound proteinase activity is released during spheroplast formation under conditions which result in the release of only 1% of the intracellular enzymes aldolase and glyceraldehyde-3-phosphate dehydrogenase. The solubilized cell wall, plasma membrane, and cytoplasm fractions contained 84, 0, and 16%, respectively, of the total proteinase activity with casein as substrate. The physiological role of a surface-bound proteinase in this organism is discussed.

An early event in septic shock is the activation of macrophages by a complex consisting of lipopolysaccharide (LPS), LPS-binding protein (LBP), and the cell surface antigen CD14. The complexes that form between [3H]ReLPS (ReLPS is deep-rough-chemotype hexacyl LPS from E. coli D31m4), soluble CD14 (sCD14), and LBP were analyzed by two independent methods, native (nondenaturing) gel electrophoresis and size-exclusion high-performance liquid chromatography (HPLC). This is the first reported use of HPLC to purify and study LPS-protein complexes. The binding of [3H]ReLPS to LBP and sCD14 was inhibited by preincubation with diphosphoryl lipid A from Rhodobacter sphaeroides (RsDPLA), a potent LPS antagonist. In addition, [3H]ReLPS bound to LBP and to a truncated form of sCD14 [sCD14(1-152)] that contained the LPS binding domain. Binding to both proteins was blocked by RsDPLA. Thus, RsDPLA competes in a 1:1 ratio for the same or nearby binding sites on ReLPS complexes. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of aggregated ReLPS eluting from the HPLC indicated that only LBP, not sCD14, was bound to the aggregated ReLPS. This finding supports the binary model of LPS complex formation with LBP and sCD14.

The transcription factor Sp1 plays a crucial role in the monocyte-specific expression of CD14, a binding site (or putative receptor) for lipopolysaccharide (LPS) complexes with LPS-binding protein (LBP). By using RAW 264.7 macrophages treated with spectrally pure deep-rough-chemotype hexa-acyl LPS from Escherichia coli D31m4, three inhibitors were found to block the binding activity of transcription factor Sp1, as measured by electrophoretic mobility shift assays. These inhibitors were diphosphoryl lipid A from Rhodobacter sphaeroides (10 microg/ml); the isoquinoline-sulfonamide H-8 (10 and 100 microM), which is thought to be a cGMP-dependent protein kinase inhibitor; and the anti-inflammatory agent dexamethasone (10 microM).

Variants of Streptococcus lactisthat produce lactic acid slowly in milk were isolated by inducing plasmid loss in the wild type at 39 to 40 C. Such strains had lost most of their surface-bound proteinase activity and were designated prt-. The specific proteinase activities of S. lactisC10 prt+whole cells and solubilized cell walls were 7 and 18 times, respectively, those of the prt-strain, but spheroplast lysates of prt+and prt-strains contained similar proteinase activity. S. lactisH1 showed a similar relative distribution of activity between prt+and prt-cellular fractions, although the overall level was lower. The limited growth in milk, characteristic of prt-strains, can be explained in terms of their low surface-bound proteinase activity.

The object in this investigation was to observe the effects of the routine use of milk sugar (lactose) in infant feeding, approved methods being used for giving the other elements of the formulas the maximum digestibility.The routine use of any given type of modified infant feeding has led to a kind of "faith dispute" among physicians. This is probably due to the fact that expert work with a given method always yields commendable results. Such results tend to confirm the belief of the general practitioner that there is no panacea in infant feeding. What he wants is a simple method for the average case.The literature on infant feeding contains many opinions of the advantages of this or that sugar, but most of them lack any scientific proof of the conclusions drawn. These, combined with timely commercial propaganda, have given rise to a vast array of sugar preparations, for

Gibberellic acid breaks dormancy of hazel seeds. Markedly preceding growth of the embryonic axis is an increased RNA synthesis, as shown by total RNA determination and 32P incorporation into RNA. This increased RNA synthesis is accounted for by an increase in DNA template available for transcription and (subsequently) increased RNA polymerase activity. It is suggested that gibberellic acid breaks dormancy by a mechanism of gene derepression, as indicated by increased chromatin-directed RNA synthesis as measured in vitro.

The nutrition of Entodinium simplexwas studied, with foliage of bluegrass (Poa pratense), perennial ryegrass (Lolium perenne), and grains of wheat (Triticum vulgare) as substrates in agnotobiotic cultures. Entodiniumgrew poorly when the substrates were autoclaved; better growth was obtained when the substrates were sterilized with ethylene oxide vapor. The concentration of ethylene oxide and the amount of moisture influenced the sterility and nutritional adequacy of the treated substrate. Autolysates and hydrolysates of mixed rumen protozoa stimulated growth. Protozoal extracts did not replace factors destroyed by autoclaving. Clarified rumen fluid assisted the cultivation of entodinia from small inocula but was detrimental to established cultures. Success of cultures was influenced by the medium used to grow the inoculum as well as by the medium inoculated. The results indicated that the composition of the bacterial population influences the growth of E. simplex.

Streptococcus bovisand Butyrivibriosp. were labeled with thymidine-methyl-3H, washed, and resuspended in rumen fluid or rumen fluid fractions obtained from Holstein and Jersey cows fed alfalfa hay once daily. Factors affecting the lytic activity found in untreated rumen fluid were examined. Day to day variation and differences before and after feeding were observed for the same cow. There were also differences between cows on the same day. For a given rumen fluid, the rate of release of label was roughly proportional to the number of labeled cells present over a 100-fold range in concentration. Removal of protozoa largely abolished the lytic action of fresh rumen fluid for S. bovis, but some soluble lytic activity remained. Mixed rumen protozoa added to media containing labeled S. boviscaused label to appear in solution. In a sample of rumen fluid containing 4.3 × 104protozoa/ml 5.2% of the S. bovispopulation were destroyed by protozoa per hr. The mean rate of destruction for 12 runs on whole rumen fluid was 8.7% per hr with a standard deviation of 6.05. Parallel experiments with Butyrivibrioindicated that soluble lytic factors were more important for this organism. They could be destroyed by autoclaving and were generated when viable rumen bacteria were resuspended in autoclaved rumen fluid. The lysis of S. bovisand Butyrivibrio, at equal cell densities, by mixed rumen protozoa was compared in 30% rumen fluid media, and Butyrivibrioappeared to be more readily lysed than S. bovis.

Embryonic axes of hazel seeds sown on GA3 (non-dormant) show a higher rate of protein synthesis than those of seeds sown on water (dormant). Associated with this increased protein synthesis are changes in tRNA and aminoacyl-tRNA synthetases. These changes appear to be consequences of changes at the transcriptional level which have previously been described.

The germination of lettuce seeds is inhibited by the nucleotide base analogue 6-methylpurine. RNA synthesis has been measured during imbibition and germination as 32P-phosphate incorporation into RNA species as fractionated by polyacrylamide gel electrophoresis. Seeds were surface sterilized and imbibed in the presence of various antibiotics. RNA preparations from lettuce seeds were coelectrophoresed with 3H-RNA prepared from bacteria to check for bacterial contamination of the seeds. There is a much higher rate of RNA synthesis in illuminated, germinating seeds as compared to dark, non-germinating seeds. This difference does not develop until after 12 hours of imbibition at 27°, which is the time of onset of germination and radicle growth.

Chilling (after-ripening) of hazel seeds stimulates subsequent growth of excised embryonic axes on sucrose and leads to growth which is less susceptible to inhibition by abscisic acid. Chilling also obviates the need for inorganic salts in the culture medium. Axes from dormant seeds grow normally when only one-third of a cotyledon is left attached.

An investigation of a cluster of cases of pulmonary hemosiderosis in infants in Cleveland, OH, led to the isolation of many isolates of Stachybotrys atra and two isolates of a related toxigenic fungus, Memnoniella echinata. M. echinata produces two cytotoxic trichothecene mycotoxins, trichodermol (1a) and trichodermin (1b), as well as several griseofulvins. Dechlorogriseofulvin (2a) and epidechlorogriseofulvin (2b) were the major compounds isolated. This is the first report of a fungus outside the Penicillium genus producing griseofulvins.

GA3 and cotyledon excision (which break dormancy) change the size distribution of RNA containing polyadenylic acid [poly(A)+RNA] synthesised at 24 hr in the embryonic axes of hazel (Corylus avellana L.) seeds. This difference precedes germination by at least five days. GA3 induces a similar size change in excised axes in liquid culture. Poly(A)+RNA from dormant and non-dormant seeds support in vitro translation into a large number of polypeptides, most of which are present in both treatments. GA3 represses the synthesis of some peptides and promotes the synthesis of others. The change in size and encoded peptides of poly(A)+RNA is the first direct evidence consistent with the suggestion that dormancy breaking may be associated with the transcription of novel mRNAs specific for germination. After two-dimensional electrophoresis, the pattern of polypeptides labelled in vivo is different from the pattern of peptides synthesised in vitro, suggesting that there is strong translational control in hazel axes. The poly(A) in the newly synthesised poly(A)+RNA from axes of dormant and non-dormant seeds are of similar size. A greater level of messenger activity is detectable in RNA lacking poly (A) [poly(A)−RNA] than in poly(A)+RNA in imbibed dormant and non-dormant axes. Poly(A)+mRNA and poly(A)−mRNA are present in axes of dry seeds, the former declining markedly during storage.