Coaggregation of urogenital bacteria in vitro and in vivo

The working hypotheses of the present study were that (1) bacterial coaggregates exist in the urogenital tract of healthy and infected women, and (2) coaggregation reactions can occur in vitro between members of the urogenital flora. Examination of urogenital specimens from 25 healthy women showed that lactobacilli were the dominant organisms colonizing the epithelia and coaggregating with other Gram-positive and Gram-negative bacteria. In vitro light and electron microscopic studies confirmed that members of the urogenital flora could coaggregate. An examination of specimens from 9 women with urinary tract infection showed the presence of autoaggregated uropathogens free-floating in the urine and attached to epithelial cells. The phenomenon of autoaggregation was also noted in vitro for various uropathogens, suggestive that this may represent a virulence factor. It is evident that bacterial cell-to-cell binding within a strain and among different genera occurs in the urogenital tract. Further studies of the mechanisms that maintain and disrupt these microbial interactions will help to improve our understanding of disease initiation.     

Influence of the spermicidal compound nonoxynol-9 on the growth and adhesion of urogenital bacteria in vitro

Lactobacilli and uropathogenic bacteria isolated from the female urogenital tract were tested for their susceptibility to nonoxynol-9. Nonoxynol-9 is a spermicidal compound, generally used at a concentration of 5% in cream and 12.5% in foam. The growth of 67% of fresh, vaginal lactobacillus isolates was inhibited by concentrations of nonoxynol-9 between 0.1% and 1.0%; these were termed sensitive. Of a total of 47 lactobacilli from various sources, 55% were found to be sensitive to nonoxynol-9, being bacteriostatic for 42% of these isolates and bactericidal for the remaining 58% at N-9 concentrations 1.0%. The remaining lactobacilli and 96% (48/50) of uropathogenic organisms had minimal inhibitory concentrations of 25% for nonoxynol-9. Inhibition of the lactobacilli did not appear to be species specific nor related to the source of the lactobacilli. The adhesion of Gram-positive bacteria, namely lactobacilli and enterococci, to HeLa cells in tissue culture was significantly increased over 60 min in the presence of physiologically used concentrations of nonoxynol-9; however, adhesion ofEscherichia coli was not affected. We believe that nonoxynol-9 has the potential to increase susceptibility to urinary tract infection in women using spermicidal preparations for contraception by inhibiting the growth of lactobacilli, which are believed to have a protective function in the vagina, and allowing overgrowth of uropathogenic bacteria.     

Transport axonal de protéines marquées dans le motoneurone géant de l'écrevisse

Isolated abdomens of crayfish were maintained in vitro and lysine (-³H) was intracellularly injected into one of the giant motoneuron of the ventral cord ganglia by iontophoresis. Membrane potentials ranging between -60 and -70 mV were recorded all along the experiment. Light microscope radioautographs showed an intense reaction over the injected nerve cell body and the initial segment of its axon; most of the surrounding tissues were free of radioactivity when the diffusion of the injected lysine (-³H) was prevented by adding cold lysine to the bathing medium. Some exchange of label was however noted with electrically coupled axons and glial sheaths. No radioactive protein could be traced in the numerous nerve endings of the neuromuscular junction. Nonetheless when a ligature was placed on the nerve root, the amount of accumulated radioactivity was increased from 3 to 6 h. in the axon of the injected motoneuron only. Electron microscope radioautographs indicate that the fast transported proteins were mainly associated with the endoplasmic reticulum and the axonal membrane. It is concluded that the visualization of the nerve endings was limited by the dispersion of the label into the numerous thin terminal branchs of the axon; however the combination of iontophoretic injection and radioautography permits to trace endogenous protein along the axon and to study molecular exchanges with other cells.     

Observations on the use of solid-phase-coupled antibodies in the radioimmunoassay of human placental lactogen

A detailed comparative assessment was made of the use of solid-phase-coupled antibodies in radioimmunoassay, by using an assay for human placental lactogen as a model system. The major advantages of the solid-phase technique are: (1) in common with the use of a second antibody, it is universally applicable; (2) separation can be carried out rapidly; (3) in contrast with some other techniques, the separation of antibody-bound and free antigen is virtually complete. The disadvantages when compared with other procedures are: (1) a considerable proportion of the antibody may be lost during the initial coupling reaction; (2) the tubes must be continuously mixed during incubation, and much effort is expended in removing and replacing the caps; (3) there is a decrease in the apparent affinity constant of the antibody after coupling, which is reflected in a lower sensitivity of the assay system. It is concluded that solid-phase antibodies are of greatest value in those systems in which the supply of antiserum is abundant, and in which the achievement of high sensitivity is not a requirement.     

Genetic alteration of structure and function in glycine transfer RNA of Escherichia coli: Mechanism of suppression of the tryptophan synthetase A78 mutation

Suppression (su_A78⁺) of the trpA78 missense mutation (Gly,GGU/C → Cys,UGU/C) in Escherichia coli involves a genetically altered tRNA^Gly isoacceptor. Purification and sequence analysis of ³²P-labeled suppressor tRNA indicates that the su_A78⁺ mutation results in the alteration of a small fraction of the tRNA_GGU/C^Gly3 of the cell. The resulting tRNA_UGU/C^Gly3 contains a C → A substitution at the 3′ end (C36) of the anticodon (GCC) and in addition, a modification of the adjacent A(A37) to form N⁶-(Δ²-isopentenyl)-2-thiomethyl-adenylic acid. Labeled glycyl-tRNA_UGU/C^Gly3 binds to E. coli ribosomes in the presence of the cysteine triplets, UpGpU and UpGpC, but not with the glycine triplets, GpGpU and GpGpC. The suppressor tRNA_UGU/C^Gly3 glycylates relatively slowly in the presence of the glycyl-tRNA synthetase, with a V_max value 200-fold lower than that of wild-type tRNA_GGU/C^Gly3. Multiple identical copies of genes specifying the sequence of tRNA_GGU/C^Gly3 apparently occur on the E. coli chromosome, since suppressor mutations alter the nucleotide sequence of only a fraction of the tRNA_GGU/C^Gly3 population.     

Biosynthesis and the isolation of the new anthracyclin antibiotics, violamycins A, BI, BII and their aglycones]

The conditions of fermentation, isolation and some of the physico-chemical properties of the new anthracycline antibiotics, i. e. viomycin A, BI, BII and their aglycones, produced by a strain of Streptomyces violaceus IMET JA 6844 are described. Violamycin A is mainly a complex of aminoglycosides of epsilon- and dzeta-isorhodomycinone, beta-rhodomycinone and (alpha)2-rhodomycinone. The sugar component is rhodosamine. Violomycin BI is mainly a complex of trisaccharides of the same aglycones mentioned above. The sugar components are rhodosamine, 2-desoxy-L-fucose and rhodinose. Violomycin BII is mainly a rhodosaminyl-2-desoxy-L-fucosyl-derivative of epsilon- and dzeta-isorhodomycinone, beta- and epsilon-rhodomycinone and (alpha)2-rhodomycinone. Violamycin complexes A, BI, BII mainly consist of 6 aglycone components which are similar to the other members of anthracyline antibiotics but can be diferentiated from them by physico-chemical and biological properties. Epsilon- and dzeta-isorhodomycinone, epsilon- and (alpha)2-rhodomycinone and dzeta-rhodomycinone one of the 8 minor components contained in the mixture of the aglycones of the violomycin complex so far has been determined as constituents of an antibiotic.     

Damage and performance of the green spruce aphid, Elatobium abietinum on twenty spruce species

Field and laboratory observations of the relationships between the performance of Elatobium abietinum (Walker), Homoptera, Aphididae, and various species of spruce were undertaken from January 1980 to April 1981. The study included sampling for aphids in established field plots of spruce during May and June respectively before and after the migration period in spring. The aphid's performance (weight and mean relative growth rate) at different seasons on pot grown plants of selected spruce species was monitored, covering, in all, 20 species of spruce.Aphid performance was greatest on the North American spruces, especially Picea sitchensis (Bong) Carr and P. mexicana Martinez; the Asian spruces were the least favoured, especially P. glehnii (Schmidt) Mast. Between these two geographical groups the Eurasian spruce species (sensu Wright, 1955) demonstrated an intermediate aphid performance.

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Résumé Les observations dans la nature et au laboratoire sur les performances d'E. abietinum Walker et différentes espèces d'épicéas ont été effectuées de janvier 1980 à avril 1981. Les observations dans la nature comprenaient des prélèvements de pousses d'épicéa pour dénombrer les pucerons avant (mai) et après (juin) la période de migration du printemps. Les performances des pucerons (poids et taux moyen de croissance relative) ont été examinées à différentes saisons sur des plantes en pot sur un total de 20 espèches sélectionnées d'épicéas.Les performances du puceron ont été supérieures sur les espèces d'épicéa de l'Amérique du nord Picea sitchensis et P. mexicana; les espèces asiatiques étaient les moins favorables, particulièrement P. glehnii. Entre ces deux groups géographiques, les espèces eurasiennes (sensu Wright, 1955) ont permis des performances intermédiares chez les pucerons.

     

Opsonization with Antimyelin Antibody Increases the Uptake and Intracellular Metabolism of Myelin in Inflammatory Macrophages

In most demyelinating diseases, macrophages are believed to be active agents of myelin destruction. In experimental encephalomyelitis, these cells appear to strip off and ingest the myelin lamellae, and myelin debris has been observed within the cell body. We show here in vitro conditions in which rat peritoneal macrophages phagocytose and metabolize CNS myelin lipids. Purified rat myelin, prelabeled in vivo with [14C]acetate, was incubated with preimmune serum or rabbit antiserum to rat CNS myelin and added to macrophage monolayers. Myelin opsonized with antimyelin antibodies was more readily phagocytosed and metabolized by cultured macrophages than untreated myelin or that preincubated with preimmune serum. In the presence of macrophages, levels of myelin polar lipids and cholesterol decreased, whereas radioactive cholesterol ester and triglyceride accumulated. Up to five times as much radioactive cholesterol ester and about twice as much triglyceride accumulated in macrophage cultures containing antibody-treated myelin as in cultures fed preimmune serum-treated myelin or in those incubated with untreated myelin. Both the fatty acid and the cholesterol from cholesterol ester contained radioactive label; therefore, both were derived at least partly from the radioactive myelin lipid. Antiserum to myelin purified from peripheral nerve was almost as effective as that to CNS myelin in stimulating cholesterol metabolism, whereas antiserum to galactocerebroside was about 70% as active. Antiserum to basic protein had less effect, whereas antiserum to the myelin-associated glycoprotein and proteolipid protein was inactive. Of the polar lipids, ethanolamine phosphatide was most degraded in both the antiserum- and preimmune serum-treated myelin, with the diacyl form and plasmalogen form degraded about equally. These experiments indicate that myelin-specific antibodies in inflammatory CNS lesions may participate in and stimulate macrophage-mediated demyelination.     

Immunocytochemical localization of S-100 protein in stellate cells (folliculo-stellate cells) of the adenohypophysis in the monkeys Macaca irus and Cercopithecus aethiops

Summary With the use of an antibody against bovine S-100 protein, it was possible to reveal a characteristic cell type in the pars distalis and the pars tuberalis of the monkey Macaca irus. In the adenohypophysis of Cercopithecus aethiops, labeled cells were present in the pars distalis, pars tuberalis, and pars intermedia. These cells, so-called folliculo-stellate cells, were found in all pituitaries studied. Surprisingly, an antibody against human S-100 protein did not label the stellate cells of the adenohypophysis. However, in Macaca irus, this antibody gave a strong positive reaction with various other cell types (interstitial cells of the pineal gland, Müller cells of the retina, autonomic ganglionic cells, glial cells of the central nervous system, Schwann cells, Bergmann glia of the cerebellum, fat cells, reticular cells of lymphoid organs). By use of double immunoenzymatic labeling, it was evident that stellate cells are spatially related either to somatotropes, prolactin cells, corticotropes, or to glycoprotein-containing cells. Thus, a specific relationship to a particular endocrine-cell type could not be observed.Dr. M.P. Dubois died in Tours (France) on March 30, 1986, aged 65