Production of 6-Phenylacetylene Picolinic Acid from Diphenylacetylene by a Toluene-Degrading Acinetobacter Strain

Several strategies for using enzymes to catalyze reactions leading to the synthesis of relatively simple substituted picolinic acids have been described. The goal of the work described here was to synthesize a more complex molecule, 6-phenylacetylene picolinic acid [6-(2-phenylethynyl)pyridine-2-carboxylic acid], for use as a potential endcapping agent for aerospace polymers. We screened 139 toluene-degrading strains that use a variety of catabolic pathways for the ability to catalyze oxidative transformation of diphenylacetylene. Acinetobacter sp. strain F4 catalyzed the overall conversion of diphenylacetylene to a yellow metabolite, which was identified as a putative meta ring fission product (2-hydroxy-8-phenyl-6-oxoocta-2,4-dien-7-ynoic acid [RFP]). The activity could be sustained by addition of toluene at a flow rate determined empirically so that the transformations were sustained in spite of the fact that toluene is a competitive inhibitor of the enzymes. The overall rate of transformation was limited by the instability of RFP. The RFP was chemically converted to 6-phenylacetylene picolinic acid by treatment with ammonium hydroxide. The results show the potential for using the normal growth substrate to provide energy and to maintain induction of the enzymes involved in biotransformation during preliminary stages of biocatalyst development.     

Proposal for adoption of the base of the Undulograptus austrodentatus Biozone as a global Ordovician stage and series boundary level

The base of the Undulograptus austrodentatus Biozone appears to be a synchronous event that is widely recognizable within graptolitic facies around the world. It occurs within an interval in which graptolite species ranges are now well known and in which there is a rapid turnover in the composition of graptolite faunas. This turnover reflects the rapid evolutionary radiation of the Diplograptacea simultaneously with the appearance of several distinctive pseudisograptid and glossograptid species. These events provide the basis for the recognition of two thin but widely applicable subzones; a lower Arienigraptus zhejiangensis Subzone and an upper U. sinicus Subzone. The occurrence of the lower boundary of the U. austrodentatus Biozone within a succession of first appearances also permits accurate and reliable identification of the boundary as well as assessment of stratigraphic completeness across the boundary interval in correlated sections. Diverse graptolite faunas of late Yapeenian and early Darriwilian age occur in association with the Histiodella altifrons Biozone of the North American midcontinent conodont zonation and the Paroistodus originalis and Microzarkodina parva biozones of the North Atlantic conodont zonation. They also occur in association with the shelly-fossil zonations developed for several different continents. These features of the base of the U. austrodentatus Biozone make it a suitable level for use as the boundary level for a global stage. Its stratigraphic position within the Ordovician System relative to other likely global stages as well as its coincidence with one of the major events in graptolite evolutionary history suggest that this level also may be a suitable level for the base of a global Middle Ordovician Series.Ordovician System, Ordovician stages, graptolite zonation, chronostratigraphy, international correlation. Charles E. Mitchell and Jörg Maletz, Department of Geology, State University of New York at Buffalo, Buffalo, New York 14260-1550, USA; 13th July, 1994; revised 22nd May, 1995.     

Modulation of IL-4 production in murine spleen cells by prostaglandins

Recently, it has been reported that IL-4 production by murine Th2 cell lines is insensitive to inhibition by E-type prostaglandins. In the present study, IL-4 production in vitro by freshly isolated concanavalin A (Con A)-stimulated murine spleen cells was readily suppressed by PGE₂ with an I₅₀ of 2 nM. Comparable suppression by PGE₂ was seen after priming by anti-CD3? antibody instead of Con A or with other changes in the culture conditions. PGE₂ was an effective inhibitor after elimination of Ly2.2⁺ T cells, consistent with a direct effect on Th2 cells. In the absence of added prostaglandins, IL-4 production was enhanced 1.5- to 7.0-fold by 0.2–2.0 μM indomethacin, indicating that endogenous arachidonate metabolites such as PGE₂ and PGI₂ regulate IL-4 production in our usual culture system. The inhibition of Th2 cell secretion by PGE₂in vitro may have physiologic and pharmacologic implications for the regulation of Th2 cell function and IgE production in vivo.     

Increase in percutaneous muscle biopsy yield with a suction-enhancement technique

Hennessey, James V., Joseph A. Chromiak, ShirleyDellaVentura, Jennifer Guertin, and David B. MacLean. Increasein percutaneous muscle biopsy yield with a suction-enhancementtechnique. J. Appl. Physiol. 82(6):1739-1742, 1997.The percutaneous muscle biopsy technique is usedin clinical practice and biomedical research. We developed a newenhanced-suction technique [suction-enhancing nipples(SEN)] and compared it with techniques currently in practice byassessing biopsy yields on anesthetized pigs. We applied the enhanced-suction technique to human subjects participating in aclinical trial. In the pig, there was a mean 91% (1.9-fold) increasein the size of the samples obtained with the 4-mm needle when SEN wasused and a mean 507% (fivefold) increase in sample size when the SENwas applied to the 6-mm needles. Nine passes of the 6-mm needle withSEN obtained from five consecutive human subjects yielded a meanindividual sample size of 109.4 mg or 219.4 mg per needle pass whenusing the double-sample technique. Adequate tissue samples forhistomorphometric and other analyses were obtained in all samplesobtained. The percutaneous muscle biopsy performed with enhancedsuction using inexpensive, readily available nipples enhances tissueyield two- to fivefold.

     

A new monoclonal antibody (3D3) generated with human respiratory mucins and directed against Lewis determinants

We have prepared a monoclonal antibody (MAb), 3D3, raised againstpurified human respiratory mucins. This antibody recognizedmucins and proteolytically derived glycopeptides. The epitoperecognized by the antibody was destroyed by -L-fucosidase, indicatingthat it was present on the carbohydrate moieties. Structuralspecificity was determined by adsorption on a variety of synthetic,insolubilized oligosaccharides. Several lines of evidence indicatethat the 3D3 MAb reacted strongly with the Lewis (Le^b) antigen,but also recognized Le^a and Le^y determinants. This antibodymight be useful to study mucin secretion. human bronchial mucins Lewis b     

Myelin development in infant brain

Myelin was isolated from subcortical areas of ten human brains, with ages ranging from 24 days to 350 days-of-age; samples were subsequently analyzed for lipid composition. Eight infants were victims of Sudden Infant Death Syndrome, and two infants were accident cases. Gray and white matter samples from each brain were also dissected and analyzed. Galactolipids were only 12% of the total lipids in white matter from brains of infants that were 24 days-of-age, a time when myelination was just starting in the subcortical areas. At 175 and 350 days of age, myelination was well underway and galactolipids measured 22% of the total lipids. Total phospholipids decreased (65% to 54%) in white matter during development, with the decrease mostly in phosphatidylcholine (23% to 15%). Even though there was little white matter present at early ages, myelin could be isolated. Surprisingly, the lipid composition of myelin, from the 24-day-infant brain was similar to that from adult brain. Galactolipids were 22% of the total lipids, cholesterol, 23%, and phospholipids, 52%. These results suggest that only subtle remodeling of myelin occurs in humans once myelination commences. All four major gangliosides were present in myelin during this first year of development. Interestingly, the yield of myelin from the 350-day-old infant subcortical white matter was similar to that from an adult. Thus major tracts in this area may have acquired most of the myelin by one year-after-birth. Since the control samples blend quite well into the developmental pattern obtained, it is believed there are no abnormalities in myelin lipids from SIDS infants.     

ISOLATION AND IDENTIFICATION OF γ-AMINOBUTYRYL-CYSTATHIONINE FROM HUMAN BRAIN AND CSF

Abstract— A new dipeptide, γ-aminobutyryl-cystathionine, has been identified in human brain and CSF. The compound was isolated from peptide concentrates which were prepared by removing free a-amino acids from deproteinized brain extracts on a copper Sephadex column. The isolated peptide was shown to be GABA-Cysta by standard chemical methods, and its identification was confirmed by mass spectrometry. GABA-Cysta is present in both biopsy and autopsy specimens of adult human brain, its content in some brain areas being as high as 0.090 μrnol/g wet weight. Its concentration in CSF is much lower. What physiologic role this unusual peptide plays in brain remains to be determined.     

γ-VINYL GABA: EFFECTS OF CHRONIC ADMINISTRATION ON THE METABOLISM OF GABA AND OTHER AMINO COMPOUNDS IN RAT BRAIN

Rats were given γ-vinyl GABA (4-amino-hex-5-enoic acid), a new irreversible inhibitor of GABA aminotransferase (GABA-T), by daily subcutaneous injection (100mgkg) for 11 days. Amino acids were quantitated in the brains of the γ-vinyl GABA-treated and control animals 24 h after the last injection, and enzyme activities of GABA-T and glutamic acid decarboxylase (GAD) were measured. Chronic administration of γ-vinyl GABA produced a 150% increase in brain GABA content, along with marked increases in the contents of B-alanine and homocarnosine. Brain GABA-T activity was reduced by 26%, and GAD activity was reduced by 22%. In addition, γ-vinyl GABA caused a marked increase in hypotaurine content in rat brain, suggesting that it acts as an inhibitor of hypotaurine dehydrogenase, and it produced significant decreases in brain contents of glutamine and threonine. Although it is an effective GABA-T inhibitor, γ-vinyl GABA apparently affects several other brain enzymes as well, and it may not be an ideal drug for elevating brain GABA levels in man.     

Sexual development of patients with isochromosomes for the long arm of the X chromosome

Summary The sexual development of 14 girls with non-mosaic monocentric 46,X,iXq karyotype was studied. Seven out of eight girls were found to have immature secondary sexual characteristics and amenorrhoea, a finding greatly contrasting with that in Triplo-X girls. The relative ineffectiveness of the isochromosome Xq in maintaining fertility may be due to the absence of one short arm, which probably also carries a gonadal determinant. Alternatively, the presence of two inactivation sites on one isochromosome may render the gonadal determinants inactive at an important stage in gonadal development.