bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Antimycobacterial Evaluation of Novel Phthalazin‐4‐ylacetamides Against log‐ and Starved Phase Cultures
Authors: Sriram Dharmarajan , Yogeeswari Perumal , Senthilkumar Palaniappan , Sangaraju Dewakar , Nelli Rohit , Banerjee Debjani , Bhat Pritesh , Manjashetty Thimmappa H.
Published: February 2010

Twenty four novel 2‐[3‐(4‐bromo‐2‐fluorobenzyl)‐4‐oxo‐3,4‐dihydro‐1‐phthalazinyl]acetic acid amides were synthesized from phthalic anhydride and were subjected to in vitro and in vivo evaluation against log‐ and starved phase of mycobacterial species and Mycobacterium tuberculosis isocitrate lyase enzyme inhibition studies. Among the compounds screened, 2‐(2‐(4‐bromo‐2‐fluorobenzyl)‐1,2‐dihydro‐1‐oxophthalazin‐4‐yl)‐N‐(2,6‐dimethylphenyl)acetamide (5j) inhibited all eight mycobacterial species with MIC’s ranging from 0.08 to 5.05 μm and was non‐toxic to Vero cells till 126.43 μm. Four compounds were tested against starved culture of Mycobacterium tuberculosis and they inhibited with MIC’s ranging from 3.78 to 23.2 μm. Some compounds showed 40–66% inhibition against Mycobacterium tuberculosis isocitrate lyase enzyme at 10 μm. The docking studies also confirmed the binding potential of the compounds at the isocitrate lyase active site. In the in vivo animal model, 5j reduced the mycobacterial load in lung and spleen tissues with 1.38 and 2.9‐log10 protections, respectively, at 25 mg/kg body weight dose.
Localization and functional characterization of the human NKCC2 isoforms
Authors: Carota I. , Theilig F. , Oppermann M. , Kongsuphol P. , Rosenauer A. , Schreiber R. , Jensen B. L. , Walter S. , Kunzelmann K. , Castrop H.
Published: February 2010

Aim:  Salt reabsorption across the apical membrane of cells in the thick ascending limb (TAL) of Henle is primarily mediated by the bumetanide‐sensitive Na+/K+/2Cl− cotransporter NKCC2. Three full‐length splice variants of NKCC2 (NKCC2B, NKCC2A and NKCC2F) have been described. The NKCC2 isoforms have specific localizations and transport characteristics, as assessed for rabbit, rat and mouse. In the present study, we aimed to address the localization and transport characteristics of the human NKCC2 isoforms.

Methods:  RT‐PCR, in situ hybridization and uptake studies in Xenopus oocytes were performed to characterize human NKCC2 isoforms.

Results:  All three classical NKCC2 isoforms were detected in the human kidney; in addition, we found splice variants with tandem duplicates of the variable exon 4. Contrary to rodents, in which NKCC2F is the most abundant NKCC2 isoform, NKCC2A was the dominant isoform in humans; similarly, isoform‐specific in situ hybridization showed high expression levels of human NKCC2A along the TAL. Compared to NKCC2B and NKCC2F, human NKCC2A had the lowest Cl− affinity as determined by 86Rb+ uptake studies in oocytes. All NKCC2 isoforms were more efficiently inhibited by bumetanide than by furosemide. A sequence analysis of the amino acids encoded by exon 4 variants revealed high similarities between human and rodent NKCC2 isoforms, suggesting that differences in ion transport characteristics between species may be related to sequence variations outside the highly conserved sequence encoded by exon 4.

Conclusion:  The human NKCC2 is an example of how differential splicing forms the basis for a diversification of transporter protein function.
The Cerebral Cortex Overlying Periventricular Leukomalacia: Analysis of Pyramidal Neurons
Authors: Andiman Sarah E. , Haynes Robin L. , Trachtenberg Felicia L. , Billiards Saraid S. , Folkerth Rebecca D. , Volpe Joseph J. , Kinney Hannah C.
Published: February 2010

The role of the cerebral cortex in the cognitive deficits in preterm survivors is poorly understood. Periventricular leukomalacia (PVL), the key feature of encephalopathy of prematurity, is characterized by periventricular necrotic foci and diffuse gliosis in the surrounding cerebral white matter. Here, we tested the hypothesis that reductions in the density of layer I neurons and/or pyramidal neurons in layers III and/or V are associated with PVL, indicating cortical pathology potentially associated with cognitive deficits in long‐term survivors. In controls (23 gestational weeks to 18 postnatal months) (n = 15), a lack of significant differences in pyramidal density among incipient Brodmann areas suggested that cytoarchitectonic differences across functional areas are not fully mature in the fetal and infant periods. There was a marked reduction (38%) in the density of layer V neurons in all areas sampled in the PVL cases (n = 17) compared to controls (n = 12) adjusted for postconceptional age at or greater than 30 weeks, when the six‐layer cortex is visually distinct (P < 0.024). This may reflect a dying‐back loss of somata complicating transection of layer V axons projecting through the necrosis in the underlying white matter. This study underscores the potential role of secondary cortical injury in the encephalopathy of prematurity.
Nurse tele‐consultations with discharged COPD patients reduce early readmissions – an interventional study
Authors: Sorknæs Anne Dichmann , Madsen Hanne , Hallas Jesper , Jest Peder , Hansen‐Nord Michael
Published: February 2010

Introduction:  Exacerbations of chronic obstructive pulmonary disease (ECOPD) are the most common cause for admissions and readmissions to medical wards worldwide.

Objectives:  To investigate the effect on early readmissions of telemedicine video consultations (TVCs) between respiratory nurses placed at the hospital and COPD patients in their homes after a discharge from the hospital, which was caused by ECOPD.

Methods:  This study was an interventional study in which all ECOPD were consecutively allocated into two groups (TVC or control) depending on their home municipality. The patient received daily TVC at home with a nurse based at the hospital for approximately one week. Thereafter, the patient received at least one follow‐up call and they could call the nurse for the rest of the study period of 28 days. The telemedicine equipment was composed of a computer with a web camera, a microphone and measurement equipment.

Results:  Within each of the two groups, TVC (n = 50) and control (n = 50), 12% and 22%, respectively, were readmitted [differences between rates –10% (95% confidence interval –25;5)] because of ECOPD. The multivariate Cox regression model showed the TVC assignment as a significant protective factor for early readmission [hazard ratio (HR) 0.25 (0.09–0.69)]. High age [HR 3.94 (1.46–10.6)] and male gender [HR 2.97 (0.99–8.97)] were associated with high hazard. Patient satisfaction was high.

Conclusions:  In a hospitalised population with ECOPD, a nurse TVC assignment is protective against early readmission and reduces the days of readmission.

Please cite this paper as: Sorknæs AD, Madsen H, Hallas J, Jest P and Hansen‐Nord M. Nurse tele‐consultations with discharged COPD patients reduce early readmissions – an interventional study. Clin Respir J 2011; 5: 26–34.
Prevalence, serotyping and molecular characterization of Vibrio parahaemolyticus in mussels from Italian growing areas, Adriatic Sea
Authors: Ottaviani Donatella , Leoni Francesca , Rocchegiani Elena , Canonico Cristina , Potenziani Stefano , Santarelli Sabrina , Masini Laura , Mioni Renzo , Carraturo Antonio
Published: February 2010

The aims of this study were to investigate the prevalence of total and pathogenic Vibrio parahaemolyticus strains in Italian mussels from different geographical areas of the Adriatic Sea and to determine their serotypes, toxigenic profiles and pandemic potential. Out of 559 samples analysed during 2007, 65 (11.6%) were positive for V. parahaemolyticus. None of the isolates had the genes for thermostable direct haemolysin (tdh) and pandemic marker (toxRS), while five strains (7.7%) had that for TDH‐related haemolysin (trh). Regarding geographical location of the toxigenic strains, three were from the Adriatic coast of Puglia, one from Veneto, and one from the Marches. The trh‐positive V. parahaemolyticus isolates from Puglia belonged to O1:KUT (2/3) and O1:K37(1/3) serotypes, the trh‐positive isolate from the Marches to OUT(O untypeable):KUT serotype, and that from Veneto to O3:KUT. The prevalence of trh‐positive V. parahaemolyticus obtained from mussels in this study was higher respect to that reported in previous studies from other European and Extraeuropean countries. The Health Authorities should be more aware of the epidemiological role of environmental V. parahaemolyticus in local food‐borne diseases, and increase the microbial surveillance on these microorganisms isolated from shellfish.
Diversity and pathogenecity of Vibrio species in cultured bivalve molluscs
Authors: Beaz‐Hidalgo Roxana , Balboa Sabela , Romalde Jesús L. , Figueras Maria José
Published: February 2010

Shellfish production is seriously affected by bacterial pathogens that cause high losses in hatcheries and in the aquaculture sector. A number of Vibrio species are considered important pathogens and have provoked severe mortality outbreaks. The pathologies caused by vibrios in bivalves have been described since the 1960s; however, over recent years, successive episodes of high mortality have been recorded due to these microorganisms. The present work provides an updated overview of the different studies performed in relation with the diversity of Vibrio spp. associated to bivalves. Special attention is given to the main Vibrio diseases and implicated species affecting the different life stages of cultured bivalves.
The pre‐seventh pandemic Vibrio cholerae BX 330286 El Tor genome: evidence for the environment as a genome reservoir
Authors: Haley Bradd J. , Grim Christopher J. , Hasan Nur A. , Taviani Elisa , Chun Jongsik , Brettin Thomas S. , Bruce David C. , Challacombe Jean F. , Detter J. Chris , Han Cliff S. , Huq Anwar , Nair G. Balakrish , Colwell Rita R.
Published: February 2010

Vibrio cholerae O1 El Tor BX 330286 was isolated from a water sample in Australia in 1986, 9 years after an indigenous outbreak of cholera occurred in that region. This environmental strain encodes virulence factors highly similar to those of clinical strains, suggesting an ability to cause disease in humans. We demonstrate its high similarity in gene content and genome‐wide nucleotide sequence to clinical V. cholerae strains, notably to pre‐seventh pandemic O1 El Tor strains isolated in 1910 (V. cholerae NCTC 8457) and 1937 (V. cholerae MAK 757), as well as seventh pandemic strains isolated after 1960 globally. Here we demonstrate that this strain represents a transitory clone with shared characteristics between pre‐seventh and seventh pandemic strains of V. cholerae. Interestingly, this strain was isolated 25 years after the beginning of the seventh pandemic, suggesting the environment as a genome reservoir in areas where cholera does not occur in sporadic, endemic or epidemic form.
Automatic parameter optimization in epsilon-filter for acoustical signal processing utilizing correlation coefficient
Authors: Abe Tomomi , Hashimoto Shuji , Matsumoto Mitsuharu
Published: February 2010

ε -filter can reduce most kinds of noise from a single-channel noisy signal while preserving signals that vary drastically such as speech signals. It can reduce not only stationary noise but also nonstationary noise. However, it has some parameters whose values are set empirically. So far, there have been few studies to evaluate the appropriateness of the parameter settings for ε-filter. This paper employs the correlation coefficient of the filter output and the difference between the filter input and output as the evaluation function of the parameter setting. This paper also describes the algorithm to set the optimal parameter value of ε-filter automatically. To evaluate the adequateness of the obtained parameter, the mean absolute error is calculated. The experimental results show that the adequate parameter in ε-filter can be obtained automatically by using the proposed method.
A convenient protection for 4-oxopyrimidine moieties in nucleosides by the pivaloyl group
Authors: Sobkowski Michał
Published: February 2010

Application of the pivaloyl group as a protection for the N3 position of thymidine and uridine was investigated. Pivaloylation of thymidine is a very rapid reaction proceeding under mild conditions with excellent regioselectivity for sugar or thymine moiety, depending on the amines used. Several pivaloylated thymidine derivatives were obtained by treatment of unprotected thymidine with pivaloyl chloride under various experimental conditions. Stability of the N3-pivaloyl protecting group under basic and acidic conditions was evaluated and the conditions for its selective removal were found.
Random mutagenesis of human serine racemase reveals residues important for the enzymatic activity
Authors: Hoffman Hillary E. , Jirásková Jana , Zvelebil Marketa , Konvalinka Jan
Published: February 2010

Human serine racemase (hSR) is a cytosolic pyridoxal-5′-phosphate dependent enzyme responsible for production of D-serine in the central nervous system. D-Serine acts as an endogenous coagonist of N-methyl-D-aspartate receptor ion channels. Increased levels of D-serine have been linked to amyotrophic lateral sclerosis and Alzheimer’s disease, indicating that SR inhibitors might be useful tools for investigation or treatment of neurodegenerative diseases. However, despite hSR’s promise as a therapeutic target, relatively few specific inhibitors have been identified, which is due in part to the lack of a three-dimensional structure of the enzyme. Here, we present a strategy for the generation and screening of random hSR mutants. From a library of randomly mutated hSR variants, twenty-seven soluble mutants were selected, expressed, and evaluated for enzymatic activity. Taking three carefully characterized mutants as an example, we show how this strategy can be used to pinpoint structurally and functionally important residues. In particular, we identify S84 and P111 as residues crucial for hSR activity and C217 and K221 as residues important for binding of the Mg2+ cofactor as well as for overall stability of the enzyme.
Monoterpene and morphological variation and hybridization of Pinus contorta and P. banksiana in Alberta
Authors: Pollack John C. , Dancik Bruce P.
Published: February 2010

Five xylem oleoresin monoterpenes and 17 morphological characters of trees in four pine stands in Alberta were measured to delineate pure lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) from jack pine (P. banksiana Lamb.) in a region where hybridization commonly has been reported. Multivariate analysis determined α-pinene, β-phellandrene, and needle length best separated the taxa. The monoterpene composition of two putative hybrid stands at Onoway and Devon closely resembled that of jack pine. Analysis of the four major monoterpenes in an additional 10 stands allowed the identification of a transition zone between jack pine and lodgepole pine stands, which occurred farther west than previously reported and contained stands of highly variable monoterpene types. Trees in this region morphologically resembled lodgepole pine. The presence of variant monoterpene types in Front Range lodgepole pine stands and their absence from the Cypress Hills provide evidence for introgression of jack pine into lodgepole pine. No evidence of gene flow from lodgepole pine to jack pine was found. The two putative hybrid stands at Onoway and Devon probably consisted mostly of jack pine, with a small complement of hybrids.
Relations entre hypolignification et état vitreux chez Salix babylonica en culture in vitro. Rôle de la nutrition ammoniacale
Authors: Daguin F. , Letouze R.
Published: February 2010

The relationship between nitrogen-fed willow cuttings cultured in vitro and the appearance of vitreous plants has been studied. By using two basal media (Murashige and Skoog medium and Knop medium half diluted) an in vitro culture scheme has been developed which allows the control of the vitrification process by varying the nitrogen supply in the culture media. The results obtained agree that the vitrification of the cloned plants is directly associated with the ammonium content of the culture medium. In vitrified plants, lignin content of the shoot is reduced by 50%. Correlatively, histological controls at different levels of the shoot of the plantlets show that the reduction of the xylem tissue can reach 70%.
Production and genetic analysis of partial hybrids from intertribal sexual crosses betweenBrassica napusandIsatis indigoticaand progenies
Authors: Tu Y. Q. , Sun J. , Ge X. H. , Li Z. Y.
Published: February 2010

With the dye and medicinal plant Isatis indigotica (2n = 14) as pollen parent, intertribal sexual hybrids with Brassica napus (2n = 38, AACC) were obtained and characterized. Among a lot of F1plants produced, only five hybrids (H1–H5) were distinguished morphologically from female B. napus parents by showing low fertility and some characters of I. indigotica, and also by having different chromosome numbers. H1–H4 had similar but variable chromosome numbers in their somatic and meiotic cells (2n = 25–30), and H5 had 2n = 19, the same number as the haploid of B. napus. GISH analysis of the cells from H1 and H5 detected one I. indigotica chromosome and one or two chromosome terminal fragments. New B. napus types with phenotypic and genomic alterations were produced by H1 after pollination by B. napus and selfing for several generations, and by H5 after selfing. A progeny plant (2n = 20) was derived from H1 after pollination by I. indigotica twice and had a phenotype similar to a certain type of B. rapa, showing that hybrid H1 likely retained all chromosomes of the A genome and lost some of the C genome in parental B. napus. The reasons for the formation of the partial hybrids with unexpected chromosomal complements and for the chromosome elimination are discussed.
STUDIES ON THE PROPAGATION OF INFLUENZA AND MUMPS VIRUSES IN TISSUE CULTURE WITH CHEMICALLY-DEFINED MEDIA
Authors: Burr M. M. , Campbell M. E. , Morgan J. F. , Nagler F. P.
Published: February 2010

Optimal conditions have been established for the propagation of influenza virus (PR8 strain) in various chick embryonic tissues cultivated in synthetic medium 199. The propagation of several other influenza strains, both standard laboratory and freshly-isolated, and of mumps virus, has also been studied. Comparative investigations with virus-infected tissues cultivated in medium 199 and in simple inorganic salt solutions have shown that the extent of virus propagation is more dependent on the intracellular material present in the tissues than on the composition of the extracellular culture medium. It has also been shown that virus propagation occurs equally well in healthy, surviving cells, in actively-growing cells, and in cells depleted of nutrients and undergoing degeneration.
A CYTOLOGICAL STUDY OF THE LYSOGENIZATION OFSHIGELLA DYSENTERIAEWITH P1 AND P2 BACTERIOPHAGES
Authors: Whitfield J. F. , Murray R. G. E.
Published: February 2010

Cytological studies have clarified the changes within the cell during the process of lysogenization by dysentery phages P1 and P2. The first stage of infection with both phages consisted of a condensation of the nuclear chromatin into annular bodies and axial filaments; there were differences in the later stages. With P1 infections, the annular and filament stages occupied about one half the latent period. The following phase consisted of expansion of the chromatinic aggregates into complex chromatinic reticula which, in the case of lysogenization, separated into discrete normal nuclear elements. The resulting cells were indistinguishable from those of the sensitive strain. In P1 virulent infections, the same stages were observed, but the cells lysed while in the expansion phase. In P2 infections, the chromatin aggregated into axial filaments, but the filaments persisted throughout the entire latent period and persisted up to lysis in the virulent infections. During lysogenization, the filament separated into discrete normal nuclear elements. The expansion was usually more advanced at the poles of the elongate cells; the first normal cells arose from this region. There is a considerable condensation of chromatin in the infected cell but the structure of the aggregates and the mode of recovery suggest that the fundamental organization of the constituents of the nuclear organelle must be retained.
A FACTOR RELEASED BY IRRADIATED CELLS THAT INDUCES RECOVERY OF VIABILITY OF ULTRAVIOLET IRRADIATED BACTERIA
Authors: Whitehead Howard A.
Published: February 2010

From an examination of the dose–survival curve of E. coli B/r, it was evident that the rate of survival increases with the number of cells plated as though the irradiated bacteria themselves contributed some growth restoring activity. Studies on the supernatant fluid from an irradiated suspension indicates the presence of a "restoring factor" which gives up to a fourfold increase in survival of a previously irradiated and washed suspension. The release of the "restoring factor" by irradiated cells is proportional to the rate of killing and not the degree of inactivation. The activity is apparently due to the release of some cellular constituents by living cells as a physiological response to radiation injury and not to cell disintegration products.
INHIBITION OF THE XYLOSE ISOMERASE OFPSEUDOMONAS HYDROPHILABY SULPHYDRYL REAGENTS AND THE EFFECT OF GLUTATHIONE
Authors: Hochster R. M.
Published: February 2010

Xylose isomerase of Pseudomonas hydrophila has been found to be strongly inhibited by substances known to combine with or oxidize sulphydryl groups of proteins. Considerable variation exists in the effectiveness of these inhibitors. Complete enzyme inhibition was observed with 2 × 10−4 M p-chloromercuribenzoate and with p-quinone, with 3.3 × 10−2 M N-ethylmaleimide and with 0.3 if iodoacetate. Glutathione, added after the enzyme and the inhibitors had been in solution, reversed only the inhibition caused by p-chloromercuribenzoate. Xylose isomerase, therefore, depends for its activity upon the integrity of sulphydryl groups.
UTILIZATION OF SODIUM CASEINATE BY SOME HOMOFERMENTATIVE LACTOBACILLI
Authors: McDonald I. J.
Published: February 2010

Species of homofermentative lactobacilli commonly associated with dairy products grew in chemically denned basal medium containing sodium caseinate while species from other sources did not. The utilization of sodium caseinate may be a useful differential characteristic in the classification of lactobacilli.
THE UTILIZATION OF PEPTIDES AND L- AND D-AMINO ACIDS BY EFFECTIVE AND INEFFECTIVE STRAINS OF RHIZOBIUM MELILOTI
Authors: Jordan D. C. , Clemente C. L. San
Published: February 2010

Washed cells of three strains of Rhizobium meliloti, effective and ineffective in the fixation of atmospheric nitrogen, were found to utilize certain di- and tri-peptides and the L-, D-, and DL-forms of several amino acids as sole sources of nitrogen. The maximum growth attained on any one amino acid isomer was a function of pH and temperature. Inhibitory effects found in certain racemic mixtures were explained by mutual stereochemical interference of the enzymes attacking the L- and D-isomers. Histidine was notable in that it yielded the greatest amount of growth at all pH values (6.0, 7.0, 7.5) with all three organisms, including the ineffective strain which did not grow at pH 6.0 or 7.5 on any other acid. All strains were relatively acid sensitive, variable degrees of growth inhibition occurring at pH 6.0. Partial hydrolysis of the peptides occurred, but stimulatory effects were observed in many instances and explained on the basis of transpeptidation. Inhibition in media containing peptides of glycine plus D-leucine was traced to an antagonistic effect between the two constituent amino acids after liberation. Although the ineffective and effective strains of rhizobia were found to differ in several ways, the most interesting feature was the stimulation of the growth of the ineffective organism by D-leucylglycine.
OBSERVATIONS ON THE ENZYMATIC DEGRADATION AND CONVERSION OF CERTAIN L- AND D-AMINO ACIDS BY AN EFFECTIVE STRAIN OF RHIZOBIUM MELILOTI
Authors: Jordan D. C.
Published: February 2010

Washed intact cells of an effective strain of Rhizobium meliloti oxidatively deaminated glycine and the L- and D-isomers of a number of amino acids. The interpretation of the data concerning ammonia recovery was complicated, however, by the probable occurrence of transamination and assimilation. Glyoxylic acid, produced by removal of the glycine amino group, was isolated as the corresponding dinitrophenylhydrazone. No anaerobic decarboxylation of glutamic acid or histidine was observed. Cell-free extracts synthesized glutamic acid from α-ketoglutaric acid when glycine, L-histidine, D-aspartic acid, or D-valine acted as amino-group donors. In addition, acetone-dried cells formed alanine from D-aspartic acid and pyruvate. Alanine racemase activity was detected in cell-free extracts and acetone-dried cells, but racemization of aspartic or glutamic acids did not occur. L-glutamic acid, formed by cell-free extracts in mixtures containing D-aspartic and α-ketoglutaric acids, may have been produced by a series of three coupled reactions involving racemization and L-and D-amino acid transamination.
EXPERIMENTAL INFECTION OF CHICK EMBRYOS WITH ENTAMOEBA INVADENS
Authors: Meerovitch Eugene
Published: February 2010

Entamoeba invadens in chick embryos, incubated at 30 °C, invaded and produced changes in the liver. The embryos did not survive more than six days at 30 °C. after inoculation of the fluid medium, with or without E. invadens, and the inoculated amoebae did not survive the death of the embryo.
THE EFFECT OF TRACE ELEMENTS ON GROWTH OF HELMINTHOSPORIUM SATIVUM AND SEVERAL RELATED SPECIES
Authors: Peterson E. A. , Katznelson H.
Published: February 2010

Zinc, manganese, and iron were shown to be essential for good growth of Helminthosporium sativum, whereas copper, cobalt, molybdenum, boron, and calcium apparently were not required. One milligram each of zinc sulphate, manganese chloride, and ferrous sulphate per liter was considered adequate to ensure maximum growth of H. sativum in simple media. H. biforme, H. halodes, and H. setariae also produced maximum growth in response to a combination of zinc, manganese, and iron.
STUDIES ON THE TRANSDUCTION PHENOMENON: II. THE OCCURRENCE OF SALMONELLA TRANSDUCING PHAGES IN NATURE
Authors: Bailey W. R.
Published: February 2010

An investigation with 115 strains of S. typhi-murium isolated from a variety of sources revealed that 12.1% (or 14 strains) carried transducing phage. The highest incidence was found among strains obtained from human sources. Suggestive evidence of antigenic changes taking place in nature is given and the possible role of transduction in the evolution of the genus Salmonella is discussed.
ON THE MECHANISM OF THE AEROBIC OXIDATION OFD-XYLOSEAND OFD-RIBOSE-5-PHOSPHATE BY CELL-FREE EXTRACTS OF PSEUDOMONAS HYDROPHILA
Authors: Stone B. A. , Hochster R. M.
Published: February 2010

Under aerobic conditions, cell-free extracts of Pseudomonas hydrophila, grown on D-xylose, oxidize D-xylose and D-ribose-5-phosphate by identical terminal pathways. Diphosphopyridine nucleotide-linked oxidation of either substrate is much more vigorous than the equivalent triphosphopyridine nucleotide-linked system. Sedoheptulose-7-phosphate is an intermediate in the presence of either substrate or cofactor. D-Glyceraldehyde-3-phosphate is oxidized in the presence of diphosphopyridine nucleotide with the concomitant uptake of the same amount of oxygen as with xylose or ribose-5-phosphate. Phosphoglycerate and phosphoenol pyruvate are rapidly converted to pyruvate, which, itself, disappears by a pathway not involving further oxygen uptake. Glyceraldehyde phosphate dehydrogenase is shown to be diphosphopyridine nucleotide specific and iodoacetate sensitive whereas glucose-6-phosphate and 6-phosphogluconate dehydrogenases are triphosphopyridine nucleotide specific and iodoacetate insensitive, both in fresh extracts and in ammonium sulphate fractions.The over-all oxidation is shown to proceed via D-glyceraldehyde-3-phosphate when diphosphopyridine nucleotide is used as coenzyme and most probably via the reactions of the pentose cycle in the presence of triphosphopyridine nucleotide. It is suggested that in the intact cell both processes occur simultaneously and compete with one another.
HYPHAL ANASTOMOSIS AND CYTOLOGICAL ASPECTS OF STREPTOMYCES SCABIES
Authors: Gregory K. F.
Published: February 2010

Two strains of Streptomyces scabies and a Streptomyces sp., strain T12, have been studied for hyphal anastomosis and its cytological consequences. The presence of multiple short hyphal bridges between neighboring hyphae and the absence of demonstrable cell walls or membranes at the points of contact are presented as evidence for anastomosis. The formation of "initial cells", as a result of hyphal fusion, was not observed. Two types of swollen bodies, deeply stained by the acid-Giemsa method, were noted. One type, identified as the residue of the parent spore, passed through a stage during which it did not stain by this method but subsequently became highly chromatinic. The second type was always terminal and developed concurrently with or subsequent to "secondary mycelium". Aerial hyphae were observed to arise directly from "primary mycelium" in S. scabies. Hyphae with cytological characteristics intermediate between primary and secondary types were observed in Streptomyces sp. T12.
STUDIES ON POLYSACCHARIDE FORMATION BY PSEUDOMONAS FLUORESCENS
Authors: Eagon R. G.
Published: February 2010

Pseudomonas fluorescens, strain OSU 64, was shown to produce only a mannan regardless of the type of carbon source employed as the nutriment. Stationary cultures were more favorable for polysaccharide formation than shaken cultures. Growth curve data indicated that polysaccharide production took place after the phase of logarithmic growth. Methylpentose was demonstrated to be present in the cells of this organism.
STUDIES ON H. PERTUSSIS LIQUID CULTURES: III. LOCALIZATION OF SURFACE ANTIGENS BY MEANS OF FLUORESCENT ANTIBODY
Authors: de Repentigny J. , Frappier A.
Published: February 2010

The fluorescent antibody technique was used in an attempt to clarify the relationship between the morphology of the surface of Haemophilus pertussis and the antigenic properties of its capsular antigens. First, specific antibodies were produced by injection into rabbits of agglutinogenic and protective surface washings of the bacilli. Then, these antibodies were made fluorescent and used to mark specifically and in situ the original capsular antigens at the surface of bacilli grown in liquid as well as on solid media. Thus was obtained morphological and specific evidence for the presence of a capsule containing antigenic material.
STUDIES ON THE EFFECTS OF PHAGOCYTIC STIMULATION ON MICROBIAL DISEASE: VII. A PRELIMINARY EXPERIMENTAL APPROACH TO AN UNDERSTANDING OF THE CORRELATION BETWEEN TUBERCULIN HYPERSENSITIVITY, THE FUNCTIONAL ACTIVITY OF THE RETICULOENDOTHELIAL SYSTEM, AND TUBERCULOUS LESIONS IN GUINEA PIGS
Authors: Kátó László , Gözsy Béla
Published: February 2010

1,4-Dimefhyl-7-isopropyl-bicyclo-decapentane (BD.I) has been shown to ameliorate the course of experimental tuberculosis of guinea pigs. Further experiments demonstrate that tuberculin reactions in BD.I treated animals, whether normal or immunized, were markedly milder than in similar but untreated groups of animals. Tuberculous lesions in BD.I treated normal and immunized guinea pigs were less severe when compared with untreated animals as seen at autopsy 6, 8, and 12 weeks after virulent superinfection. It seems that the drug does not interfere with the immune principle. Partial desensitization and the therapeutic effects are attributed to stimulation of the cellular defense apparatus.
BACTERIA FOUND IN THE AIR OVER THE ATLANTIC OCEAN
Authors: Kelly C. D. , Layne Sharon
Published: February 2010

Two return flights were made across the Atlantic Ocean from Montreal to London, England, and aerobiological samples were taken at intervals throughout the flights. This publication deals with the bacteria isolated during these flights. The bacteria were found to be very much like those found over land and included the following genera: Pseudomonas, Flavobacterium, Achromobacter, Corynebacterium, Micrococcus, Sarcina, and Bacillus.
OBSERVATIONS ON THE INITIAL CYTOLOGICAL EFFECTS OF BACTERIOPHAGE INFECTION
Authors: Whitfield J. F. , Murray R. G. E.
Published: February 2010

Chromatin aggregation is the earliest cytological effect of several phage infections (e.g. P1, P2, and T7). This occurs at low multiplicities of infection if the medium contains a sufficient quantity of sodium chloride; on salt-deficient medium this aggregation no longer appears and is replaced by fragmentation. Infections with phages T2 and T5 do not normally result in the aggregation of the host chromatin, but this does occur when the multiplicity of infection is higher than three to six phages per cell and salt is present in the medium. The appearance of nuclear aggregation as the first cytological effect of infection under these circumstances adds an additional cytological stage. In the case of infection with T5 this is followed by chromatin disappearance, which is the normal first stage. Infections with T5, at high multiplicities, on salt-deficient agar cause chromatin fragmentation and no aggregation.Chromatin aggregation was again the major alteration in cell structure when T2 bacteriophage "ghosts" were adsorbed. Since injection of phage DNA and phage multiplication do not occur under these conditions, it is concluded that adsorption alone is sufficient to cause this effect.It is hypothesized that adsorption of phage alters the host cell surface so that the cell can no longer maintain an ionic equilibrium. The shift in internal ion balance is reflected in chromatin aggregation or fragmentation depending on the salt concentration of the medium.
INHIBITION OF NONFOLIC-ACID-REQUIRING ORGANISMS BY FOLIC ACID ANTAGONISTS: MECHANISM OF REVERSAL
Authors: McGlohon Virginia Mims , Peterson Barbara Hoevet , Bird O. D.
Published: February 2010

Although folic acid antagonists have been reported to be unable to inhibit nonfolic-acid-requiring organisms, it was found that several such antagonists were quite active inhibitors of Lactobacillus arabinosus and several species of yeasts when grown in minimal media. The growth inhibition produced under these circumstances was not reversed by compounds related to folic acid but was reversed by thiamine and vitamin B6compounds. A rapidly developing physiological adaptation caused by the presence of thiamine and vitamin B6apparently was the mechanism by which these organisms overcame the inhibitory effects of folic acid antagonists. 6-Mercaptopurine antagonized this reversal and thus was strongly synergistic with folic acid analogues under certain conditions.
OBSERVATIONS ON THE METHIONINE NUTRITION OF STREPTOCOCCUS LACTIS
Authors: Husain I. , McDonald I. J.
Published: February 2010

In a medium containing pyridoxal, a strain of S. lactis grew when arginine, histidine, isoleucine, leucine, phenylalanine, proline, valine, and either methionine, homocysteine, or cystathionine were supplied. Serine did not stimulate growth with homocysteine. In a medium with a mixture of 18 amino acids, pyridoxal was not required for growth; methionine was essential but homocysteine or cystathionine failed to replace methionine unless pyridoxal was present. These results indicated that conversion of homocysteine to methionine by this organism may involve vitamin B6but not serine.
OBSERVATIONS ON THE EFFECT OF AMINO ACIDS ON THE GROWTH INITIATION OF RHIZOBIUM MELILOTI, WITH SPECIAL REFERENCE TO THE SYNTHESIS OF ALANINE FROM PYRUVATE AND AMMONIUM IONS
Authors: Jordan D. C.
Published: February 2010

Washed cells of Rhizobium meliloti were capable of forming pyruvate from glucose and, in addition, washed cells and sonic extracts possessed a reversible alanine dehydrogenase, capable of forming alanine from pyruvate and NH4+. This synthesis of alanine was optimum at an alkaline pH and at a substrate concentration of 0.025 M and was stimulated by diphosphopyridine nucleotide but not by triphosphopyridine nucleotide. Sonic extracts in the presence of NH4+also formed glutamate from α-ketoglutarate and aspartate from fumarate. Nevertheless, washed cells did not initiate growth in a 0.25% carbohydrate medium, containing NH4Cl, unless amino acids were present. These requisite acids either could be supplied in the medium, or the cells could be forced to synthesize them by addition to the medium of increased levels of certain compounds, such as 0.9% glucose, from which NH4+-accepting compounds could be produced. If the stimulative effect of amino acids in low-carbohydrate media were a result of an increase in the accumulation of such NH4+-acceptors such an accumulation did not apparently result from increased carbohydrate oxidation or decreased "oxidative" assimilation, since NH4+and α-dinitrophenol, which do not initiate growth, were more active, respectively, in these two latter aspects than the amino acid (histidine) tested. On the basis of several considerations it is hypothesized that the primary effect of the growth-initiating amino acid may be directed toward the synthesis of a labile protein, intimately connected with growth, which is destroyed in resting cells.
SOME VITAMIN AND AMINO ACID INTERRELATIONSHIPS IN ESCHERICHIA COLI 113-3: I. THE INHIBITORY EFFECTS OF CYSTINE AND CYSTEINESULPHINIC ACID
Authors: McLaughlan J. M.
Published: February 2010

Cystine, cysteinesulphinic acid (CSA), and other closely related sulphur-containing amino acids inhibited growth of Escherichia coli 113-3, particularly in aerobic conditions. The cystine inhibition was completely prevented by aspartic acid, partially reversed by pantothenic acid or β-alanine and slightly reversed by lysine or thiamine. The inhibitory effect of CSA was completely or partially reversed by aspartic acid, lysine, glutamic acid, proline, ornithine, or homoserine. Aspartic acid and glutamic acid appeared to reverse the inhibition competitively while lysine seemed to reverse the inhibition in a noncompetitive manner. Reversal of the inhibitory effect of relatively high concentrations of CSA by lysine was not complete, however, unless methionine was also present. Possible mechanisms of the cystine and CSA inhibition are discussed.
THE OXIDATIVE METABOLISM OF RHODOTORULA GRACILIS
Authors: Litchfield John H. , Ordal Z. John
Published: February 2010

The oxidative metabolism of Rhodolorula gracilis NRRL Y-1091 was investigated. Data was presented showing the oxidation of glucose, acetate, pyruvate, xylose, D- and L-arabinose, by both glucose- and xylose-grown cells. Gluconate was oxidized by the glucose-grown cells, while ribose was oxidized by the xylose-grown cells. Cell-free extracts of glucose-grown cells oxidized glucose, gluconate, glucose-6-phosphate, fructose-6-phosphate, fructose-1,6-diphosphate, and ribose-5-phosphate. Pentose phosphate was demonstrated as a product of glucose-6-phosphate oxidation. Resting-cell suspensions were unable to oxidize citrate, but they oxidized the dicarboxylic acids of the TCA cycle. Citrate was detected as a product of the oxidation of acetate, pyruvate, and malate in the presence of fluoroacetate. Cell-free extracts of glucose-grown cells oxidized citrate, isocitrate, and the dicarboxylic acids of the TCA cycle.
GROWTH FACTOR RELATIONSHIPS OF SOIL MICROORGANISMS AS AFFECTED BY PROXIMITY TO THE PLANT ROOT
Authors: Cook F. D. , Lochhead A. G.
Published: February 2010

A comparison was made of the growth factor requirements and growth factor synthesizing capacity of bacteria from control soil, rhizosphere, and rhizoplane of wheat. Organisms for which growth factors were essential were proportionately much less abundant at or near the root than in more distant soil; this is ascribed chiefly to lower percentages of forms requiring thiamine, biotin, and vitamin B12. At the rhizoplane proportions of bacteria requiring growth factors were as low as, or lower than, in the rhizosphere. Bacteria capable of synthesizing growth-promoting substances were proportionately much more numerous in the root zone than in control soil. Somewhat greater capacity was shown by rhizoplane than by rhizosphere isolates. Fungi characteristic of the rhizoplane showed the highest capacity for vitamin production.The occurrence of growth-promoting substances at or near the root is attributable chiefly to microbial synthesis rather than to root excretion. This is the reverse of the situation believed to exist respecting amino acids. The preferential stimulation of growth factor synthesizing organisms is regarded as an indirect effect of plant growth—a reflection of the direct stimulation of amino acid requiring forms, a group with pronounced capacity for vitamin synthesis.
IMPROVEMENTS IN THE TISSUE CULTURE SAFETY TESTING OF SALK VACCINES
Authors: French R. C. , Armstrong R. E. , Yarosh W.
Published: February 2010

Under the conditions of the official Canadian test, it was found that two simultaneous first-order reactions were in competition. Thus, after 4 hours, while 15% of any initial live MEF1 poliovirus present was adsorbed to the monkey kidney cells, 9% of the virus was destroyed by spontaneous inactivation. When the adsorption rate was increased by decreasing the volume of fluid, it was found that significantly more isolations of virus were obtained. Utilizing the method of Baron for the concentration of polio virus it was found possible to maintain a low test volume without making the routine test unduly cumbersome. The modified test is simpler and more sensitive and may be used with undialyzed vaccines.
STUDIES ON ISARIA CRETACEA: MORPHOGENESIS OF THE SYNNEMA AND ENDOGENOUS NUTRITION
Authors: Taber W. A.
Published: February 2010

The indeterminate-growing synnema of Isaria cretacea arises from the vegetative mat when it is grown on No. IS-M synthetic medium. Synnemata development is not dependent upon the particular carbon or nitrogen source, or on the concentration of carbon, nitrogen, or phosphate of this medium. Development does require more exogenous biotin and thiamine than is required for maximal vegetative mat growth. Sucrose is a specific inhibitor of synnemata development and when it replaces the glucose of the medium the mat grows more profusely, the pH drops further, and synnemata do not appear. Addition of indoleacetic acid, which inhibits endogenous respiration of I. cretacca, to the sucrose medium retards vegetative mat growth (primary vegetative growth) and initiates synnemata growth (secondary vegetative growth). Addition of calcium carbonate or phosphate buffer also results in the development of synnemata but does not retard vegetative mat growth. It was concluded that the synnema is the product of the change of the center of growth from the hyphal tips of the vegetative mat to the hyphal tips of privileged vertical hyphae. Efficient translocation and a potentiality for indeterminate growth would seem to be requirements for synnemata morphogenesis. Secondary growth ordinarily follows primary growth but the sequence can be interrupted if an exogenous nutrient favors either continued primary growth or rapid staling of the medium. The data suggested that the synnema was synthesized from endogenous nutrients and this conclusion was supported by the observation that synnemata readily developed from washed mycelium that had been placed in a nutrient-free moist chamber.
UTILIZATION OF CARBOHYDRATES AND AMINO ACIDS BY MICROCOCCUS RADIODURANS
Authors: Raj Harkison D. , Duryee Frances L. , Deeney Anne M. , Wang Chih H. , Anderson Arthur W. , Elliker Paul R.
Published: February 2010

The nutrition and metabolism of a recently isolated Micrococcus species resistant to closes of gamma radiation as high as 6 × 106 r.e.p. were studied by manometric and radioactive tracer techniques. Methionine, the only amino acid shown to be essential in a chemically defined medium, appears to be rapidly incorporated into the cells. DL-Glutamic acid is readily metabolized, the D isomer apparently after an initial lag. Among the simple carbohydrates, fructose, glucose, and glycerol are readily utilized. The operation of the tricarboxylic acid cycle is suggested by the oxidation of certain TCA intermediates. The prompt conversion of C-1 of gluconate to CO2, in the presence of glucose, may indicate that a C1–C5 cleavage pathway is operative for catabolism of glucose in this organism.
THE IMPORTANCE OF INOCULUM STANDARDIZATION IN NUTRITIONAL EXPERIMENTS WITH FUNGI
Authors: Ward E. W. B. , Colotelo N.
Published: February 2010

Parent culture age, method of homogenation, and quantity of inoculum per culture flask were investigated for their influence on variability in yield in studies of the vitamin nutrition of a low-temperature basidiomycete. Age of parent cultures affected yield both in complete media and in basic (vitamin-free) media, in the latter presumably because of vitamin carry-over. Saline used as a suspending medium for homogenate preparation was found to be inhibitory when compared with water; the length of time of homogenizing, over the range tested, was without significant effect on either the mean yield or the variation between replicates. Variability between replicates was found to be inversely related to the quantity of inoculum per culture flask over a certain range, and yield tended to increase with increasing inoculum up to a limit.The results emphasize the necessity of adopting a standard procedure for the preparation of inoculum if quantitatively reproducible results are to be obtained.
HEXOKINASE ACTIVITY OF YEASTS GROWN ON BIOTIN-RICH AND BIOTIN-DEFICIENT MEDIA
Authors: Siepmann Rolf , MacDonald James C.
Published: February 2010

Two strains of Saccharomyces cerevisiae and one of Candida parapsilosis were grown on biotin-deficient and on biotin-rich media and the hexokinase activity in cell-free extracts determined. Extracts from C. parapsilosis grown on the biotin-deficient medium had more hexokinase activity than extracts from the organism grown on biotin-rich medium. The hexokinase activity of extracts from these yeasts grown on biotin-deficient medium was not increased by biotin, or inhibited by avidin dissolved in saline. The results do not confirm the possibility of a direct role for biotin in hexokinase activity.
GROWTH RESPONSE OF CHLAMYDOMONAS AND HAEMATOCOCCUS TO THE VOLATILE FATTY ACIDS
Authors: Stross Raymond G.
Published: February 2010

The first five straight-chain saturated fatty acids were tested to determine their effect on cell division of phytoflagellates. Chlamydomonas reinhardti Danseard and Haematococcus pluvialis Flotow were selected for measurement because of information available from similar studies of the long-chain acids. Cultures were grown at five concentrations of the sodium salt within the range of 0.5 to 10.0 mmoles/liter.Acetate stimulated the rate of cell division, while butyrate, the other acid with an even number of carbons, produced an inconsistent although negligible effect.The fatty acids with an odd number of carbons inhibited division of cells, with propionate being most and valerate least effective. Inhibition in these tests, in which initial pH was kept constant, was proportional to the initial concentration of the acid salt. Additional tests showed propionate inhibition to be approximately proportional to a calculated amount of undissociated acid in the medium. H. pluvialis was 9–12 times more sensitive than was C. reinhardti.The possibility of propionic acid inhibition of algae in acid lakes is discussed.