GROWTH FACTOR INTERACTIONS IN THE TISSUE CULTURE OF TUMOROUS AND NONTUMOROUS NICOTIANA GLAUCA-LANGSDORFFII

Schaeffer , Gideon W., Harold H. Smith and Marion P. Perkus . (Brookhaven Natl. Lab., Upton, N. Y.) Growth factor interactions in the tissue culture of tumorous and nontumorous Nicotiana glauca-langsdorffii. Amer. Jour. Bot. 50(8): 766–771. Illus. 1963.—Tissues representing tumorous and nontumorous Nicotiana glauca-langsdorffii were cultured on high (5 ×) and low (1 ×) concentrations of a modified White's basal medium containing 2.9 × 10^–6m indoleacetic acid. The growth responses of tissues of both the tumorous and nontumorous genotypes to supplements of kinetin, glutamine, inositol and nucleic acid constituents added singly and in all combinations were noted on high-salt media. The nucleic acid components inhibited growth and were omitted from low-salt media. The best growth response was observed with glutamine and inositol for tissues from the tumorous hybrid and with glutamine, inositol and kinetin in the nontumorous type. Kinetin was a distinct and consistent requirement for rapid growth of nontumorous tissues, but no appreciable kinetin effect could be observed with tissues from the tumorous genotype.     

Deep-freeze preservation of cranial bones for future cranioplasty: nine years of experience in Soroka University Medical Center

Background Decompressive craniectomy is routinely performed in many neurosurgical centers to treat intracranial hypertension refractory to medical therapy as a result of head trauma, CVA or various brain tumors. When the patient survives his illness, cranioplasty with autologous bone graft or other reconstructive materials is considered to repair the skull defect. Objective This prospective study reviews the cases of decompressive craniectomies followed by later cranioplasty undertaken at our institute through the years 1996 and 2005 and describes the method used for preservation of removed bone flaps for future cranioplasty. Subjects and methods Sixty-eight patients underwent decompressive craniectomies since 1996. A protocol was designed to prepare the removed bone flaps for deep freeze preservation. After removal, the bone flaps were transferred to the skin bank at our institution within 6 h, gently rinsed using 1–3 liters of sterile saline (0.9% NaCl) supplemented with antibiotics (neomycin, 2 mM) with no dimethylsulfoxide (DMSO), then flaps were wrapped in two layers of sterile plastic coverage and preserved at −80°C. Results The patient’s population will be presented. Since 1996 we have performed 12 cranioplasties using deep-freeze preserved autologous bone graft. It took a rather long learning period, beginning with a single patient per year and continued with several others. Up to now, no case of infection, osteomyelitis or bone resorption following cranioplasty have occurred. Conclusion Deep-freeze preservation of autologous bone grafts to reconstruct skull defects after decompressive craniectomy is a useful procedure and has a low revision rate. N. Grossman: deceased 23 December 2006.     

Genome Sequence of Stenotrophomonas maltophilia PML168, Which Displays Baeyer-Villiger Monooxygenase Activity

Stenotrophomonas maltophilia PML168 was isolated from Wembury Beach on the English Coast from a rock pool following growth and selection on agar plates. Here we present the permanent draft genome sequence, which has allowed prediction of function for several genes encoding enzymes relevant to industrial biotechnology, including a novel flavoprotein monooxygenase.     

Assessment of the working range and effect of sodium dichloroisocyanurate on Pseudomonas aeruginosa biofilms and planktonic cells

Sodium dichloroisocyanurate (NaDCC) is a chemical agent that acts against microorganisms in a manner similar to that of sodium hypochlorite by releasing free available chlorine. NaDCC has been approved by the WHO for the emergency treatment of water and by the US EPA for routine treatment of water. Previous studies assessing the effectiveness of NaDCC for the treatment of water implied that NaDCC should have a wide array of disinfecting effects beyond the treatment of planktonic cells in potable water. In this study the biocidal effects of NaDCC against Pseudomonas aeruginosa cells in different growth modes including planktonic cells and biofilms were explored. The data showed that a 60% dilution of the standard NaDCC solution was effective in the treatment of both P. aeruginosa planktonic cells and biofilms.     

Structural insight into the ligand specificity of a thermostable family 51 arabinofuranosidase, Araf51, from Clostridium thermocellum

The digestion of the plant cell wall requires the concerted action of a diverse repertoire of enzyme activities. An important component of these hydrolase consortia are arabinofuranosidases, which release L-arabinofuranose moieties from a range of plant structural polysaccharides. The anaerobic bacterium Clostridium thermocellum, a highly efficient plant cell wall degrader, possesses a single alpha-L-arabinofuranosidase (EC 3.2.1.55), CtAraf51A, located in GH51 (glycoside hydrolase family 51). The crystal structure of the enzyme has been solved in native form and in 'Michaelis' complexes with both alpha-1,5-linked arabinotriose and alpha-1,3 arabinoxylobiose, both forming a hexamer in the asymmetric unit. Kinetic studies reveal that CtAraf51A, in contrast with well-characterized GH51 enzymes including the Cellvibrio japonicus enzyme [Beylot, McKie, Voragen, Doeswijk-Voragen and Gilbert (2001) Biochem. J. 358, 607-614], catalyses the hydrolysis of alpha-1,5-linked arabino-oligosaccharides and the alpha-1,3 arabinosyl side chain decorations of xylan with equal efficiency. The paucity of direct hydrogen bonds with the aglycone moiety and the flexible conformation adopted by Trp(178), which stacks against the sugar at the +1 subsite, provide a structural explanation for the plasticity in substrate specificity displayed by the clostridial arabinofuranosidase.     

Analyses of cpDNA matK sequence data place Tillaea (Crassulaceae) within Crassula

Analysis of cpDNA matK sequences for a total of 43 members of the succulent plant family Crassulaceae, including 24 taxa of Crassula, recovered a well-supported clade comprising Crassula species that is sister to the remainder of the family. The resulting topologies do not support the monophyly of the currently recognized subgenera of Crassula, as one member of subgenus Disporocarpa (C. crenulata) is placed as sister to an otherwise monophyletic subgenus Crassula. The major synapomorphy that has been used to recognize the latter subgenus is a base chromosome number of x = 7 versus a base of x = 8 in the other subgenus. We cannot assess the utility of this feature for defining subgenus Crassula because a chromosome count of C. crenulata has yet to be published. The five accessions of the recently resurrected segregate genus Tillaea (of 24 total Crassula species) included here were placed in four separate, well-supported lineages, one of which is greatly removed from the other four accessions. This suggests that this genus is not valid and should not be recognized. An initial examination of the evolution of habit indicates that a perennial habit is ancestral and that the annual habit is a feature that has been derived at least twice in the genus.