Comparison of the pick-and-smear and Saccomanno methods for sputum cytologic analysis

The two methods of preparing sputum specimens for cytologic study, the (fresh) pick-and-smear technique and the (blended) Saccomanno technique, were compared using 249 consecutive specimens. Two slides were prepared for each specimen by each technique. Of the specimens, 103 showed squamous metaplasia, carcinoma in situ or carcinoma. A semiquantitative rating system (0 to 4+) was used to determine the number of diagnostic cells for each method for those 103 cases. More diagnostic cells were found on the Saccomanno preparations (217) than on the fresh preparations (154). There were 121 diagnostic cells in the Saccomanno preparations versus 95 diagnostic cells in the fresh preparations from 63 squamous metaplasias; 7 versus 3 for the preparations from 5 carcinomas in situ; 64 versus 42 from 28 squamous cell carcinomas; 3 versus 1 from 1 large cell undiffernomas; and 12 diagnostic cells in Saccomanno preparations versus 5 in fresh preparations from 3 small cell cancers. Twelve squamous metaplasias, two carcinomas in situ, four squamous carcinomas, one adenocarcinoma and one small cell cancer had no diagnostic cells on the fresh preparations; four squamous metaplasias and one squamous carcinoma had no diagnostic cells on the Saccomanno preparations. More diagnostic information and fewer false-negative results were achieved with the Saccomanno technique.     

Metagenomics of the subsurface Brazos-Trinity Basin (IODP site 1320): comparison with other sediment and pyrosequenced metagenomes

The Brazos-Trinity Basin on the slope of the Gulf of Mexico passive margin was drilled during Integrated Ocean Drilling Progam Expedition 308. The buried anaerobic sediments of this basin are largely organic-poor and have few microbial inhabitants compared with the organic-rich sediments with high cell counts from the Peru Margin that were drilled during Ocean Drilling Program Leg 201. Nucleic acids were extracted from Brazos-Trinity Basin sediments and were subjected to whole-genome amplification and pyrosequencing. A comparison of the Brazos-Trinity Basin metagenome, consisting of 105 Mbp, and the existing Peru Margin metagenome revealed trends linking gene content, phylogenetic content, geological location and geochemical regime. The major microbial groups (Proteobacteria, Firmicutes, Euryarchaeota and Chloroflexi) occur consistently throughout all samples, yet their shifting abundances allow for discrimination between samples. The cluster of orthologous groups category abundances for some classes of genes are correlated with geochemical factors, such as the level of ammonia. Here we describe the sediment metagenome from the oligotrophic Brazos-Trinity Basin (Site 1320) and show similarities and differences with the dataset from the Pacific Peru Margin (Site 1229) and other pyrosequenced datasets. The microbial community found at Integrated Ocean Drilling Program Site 1320 likely represents the subsurface microbial inhabitants of turbiditic slopes that lack substantial upwelling.     

PROTEINS OF AXONAL TRANSPORT: INTERACTION OF RAPIDLY TRANSPORTED PROTEINS WITH LECTINS

Rapidly transported fucose-labelled glycoproteins from the optic system of the rabbit were solubilised with the non-ionic detergent Berol 172. The major labelled components were bound to wheat germ agglutinin or Concanavalin A coupled to Sepharose but not to other lectins or glycoproteins. It was concluded that rapidly transported proteins contain exposed N-acetyl-D-glucosamine     

A note on antibiotic-resistant Escherichia coli in adult man, raw sewage and sewage-polluted River Tigris in Mosul, Nineva

A total of 600 isolates of Escherichia coli were isolated, over a 9 month period during 1984, from healthy human adults, raw sewage and the sewage-polluted River Tigris in Nineva. Over 90% of these organisms were E. coli type 1, but only 8.3% could be serogrouped as enteropathogenic E. coli . Resistance of these organisms to 11 antimicrobial drugs was assessed. Over 40% were antibiotic-resistant and of these 77.1% were resistant to more than one antibiotic. The minimal inhibitory concentration of ampicillin for 193 selected strains from the various sources was determined and ranged from <0.625- > 160 μg/ml. The high incidence of antibiotic-resistant E. coli in this locality and the possible implications to human health are discussed.     

Isopentenyldiphosphate:dimethylallyldiphosphate isomerase: construction of a high-level heterologous expression system for the gene from Saccharomyces cerevisiae and identification of an active-site nucleophile

Isopentenyldiphosphate:dimethylallyldiphosphate isomerase (IPP isomerase) is an enzyme in isoprene metabolism which catalyzes the interconversion of the fundamental five-carbon homoallylic and allylic diphosphate building blocks for the pathway. The gene encoding IPP isomerase has recently been isolated from Saccharomyces cerevisiae [Anderson, M. S., Muehlbacher, M., Street, I.P., Proffitt, J., & Poulter, C. D. (1989) J. Biol. Chem. 264, 19169-19175]. A heterologous expression system was constructed for the gene and used to overexpress IPP isomerase in Escherichia coli. In transformants carrying the expression vector, IPP isomerase activity was increased by over 100,000-fold relative to that of the untransformed host strain. The overexpressed enzyme constitutes 30-35% of the total soluble cell protein and can be purified to homogeneity in two steps. Recombinant IPP isomerase was indistinguishable from that purified from yeast. 3-(Fluoromethyl)-3-butenyl diphosphate (FIPP) is a specific active-site-directed inhibitor of IPP isomerase from Claviceps purpurea [Muehlbacher, M., & Poulter, C. D. (1988) Biochemistry 27, 7315-7328]. Inactivation of yeast IPP isomerase by FIPP was active-site-directed, and inhibition resulted in formation of a stoichiometric enzyme-inhibitor complex. The site of covalent attachment in the enzyme-inhibitor complex was determined by inactivating IPP isomerase with [4-3H]FIPP, followed by digestion of the labeled enzyme with trypsin and purification of the resulting radioactive peptides by reversed-phase high-performance liquid chromatography. The primary site of attachment was Cys-139.