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PubMed1992

Transcription of the Bacillus subtilis sacX and sacY genes, encoding regulators of sucrose metabolism, is both inducible by sucrose and controlled by the DegS-DegU signalling system.

The adjacent sacX and sacY genes are involved in sucrose induction of the Bacillus subtilis sacB gene by an antitermination mechanism. sacB, encoding the exoenzyme levansucrase, is also subject to regulation by the DegS-DegU signalling system. Using sacXY'-lacZ and sacX'-lacZ fusions, we show that the transcription of the sacX and sacY genes is both inducible by sucrose and regulated by DegU. sacX and sacY appear to constitute an operon, since the deletion of the sacX leader region abolished the expression of a sacXY'-lacZ fusion. The degU-dependent promoter was located by deletion analysis and reverse transcriptase mapping 300 nucleotides upstream from the sacX initiator codon. Sucrose induction of the sacX'-lacZ fusion requires either SacY or the homologous SacT antiterminator, which is involved in sucrose induction of the intracellular sucrase gene (sacPA operon). Sequence analysis of the sacX leader region revealed (20 nucleotides downstream from the transcription start site) a putative binding site for these regulators; however, no structure resembling a rho-independent terminator could be found overlapping this site, unlike the situation for sacPA and sacB. Deletion of a segment of the leader region located 100 nucleotides downstream from this site led to constitutive expression of the sacXY'-lacZ and sacX'-lacZ fusions. These results suggest that the mechanism of sucrose induction of sacXY is different from that of sacPA and sacB.

Bacillus subtilis↗
PubMed1998

Characterization of a novel member of the DegS-DegU regulon affected by salt stress in Bacillus subtilis.

As a soil bacterium also found in estuarine and marine habitats, Bacillus subtilis has evolved various sensing and adaptation systems in order to face salt stress conditions. Among these regulatory mechanisms is the DegS-DegU signal transduction system, which was previously shown to be stimulated by high salt concentrations. A search for promoters regulated in response to salt stress led to the identification of wapA, encoding a wall-associated protein, which is strongly expressed at low salt concentrations and almost completely repressed in the presence of 0.7 M disodium succinate. Repression of wapA transcription by salt stress was shown to require the phosphorylated form of DegU. Moreover, DegU-mediated repression of wapA occurred only in high-salt medium. Alignment between the control region of wapA and other DegU-regulated promoters allowed the identification of a putative DegU target sequence, AGAAN(11)TTCAG. Mutation/deletion analyses of the wapA promoter region confirmed the role of the putative DegU control site in repression of wapA transcription at high salt concentrations and revealed a second site of repression located downstream from the transcription start site. Since residual negative control was observed at this second site in the absence of DegU, it seems likely that an additional repressor acts on the wapA control region to further downregulate wapA transcription under salt stress conditions.

Antigens, Bacterial↗
PubMed2002

RAPD-based genetic linkage maps of yellow passion fruit (Passiflora edulis Sims. f. flavicarpa Deg.).

A single cross between two clones of passion fruit (Passiflora edulis Sims. f. flavicarpa Deg., 2n = 18) was selected for genetic mapping. The mapping population was composed of 90 F1 plants derived from a cross between 'IAPAR 123' (female parent) and 'IAPAR 06' (male parent). A total of 380 RAPD primers were analyzed according to two-way pseudo-testcross mapping design. The linkage analysis was performed using Mapmaker version 3.0 with LOD 4.0 and a maximum recombination fraction (theta) of 0.30. Map distances were estimated using the Kosambi mapping function. Linkage maps were constructed with 269 loci (2.38 markers/primer), of which 255 segregated 1:1, corresponding to a heterozygous state in one parent and null in the other. The linkage map for 'IAPAR123' consisted of 135 markers. A total of nine linkage groups were assembled covering 727.7 cM, with an average distance of 11.20 cM between framework loci. The sizes of the linkage groups ranged from 56 to 144.6 cM. The linkage map for 'IAPAR 06' consisted of 96 markers, covering 783.5 cM. The average distance between framework loci was 12.2 cM. The length of the nine linkage groups ranged from 20.6 to 144.2 cM. On average, both maps provided 61% genome coverage. Twenty-four loci (8.9%) remained unlinked. Among their many applications, these maps are a starting point for the identification of quantitative trait loci for resistance to the main bacterial disease affecting passion fruit orchards in Brazil, caused by Xanthomonas campestris pv. passiflorae, because parental genotypes exhibit diverse responses to bacterial inoculation.

Chromosome Mapping↗
PubMed1995

Unique hue judgments as a function of test size in the fovea and at 20-deg temporal eccentricity.

Unique hue loci were measured for four observers in the fovea and at 20-deg temporal eccentricity as a function of test size. Eccentric measurements were made on the cone plateau following a rod bleach. The results indicate that unique yellow remains approximately invariant with respect to test size and retinal eccentricity, whereas unique blue and unique green shift to longer wavelengths with increasing test size. The locus of unique blue in the periphery reaches an asymptote at approximately the same wavelength as that from the foveal measurements, whereas unique green measured in the periphery is consistently at shorter wavelengths than in the fovea. In general, the data are best described by a model in which the short-wavelength-sensitive cone input to the two opponent-color channels decreases with decreasing test size and increasing retinal eccentricity.

Adult↗
PubMed1992

A novel human lymphoma cell line (Deglis) with dual B/T phenotype and gene rearrangements and containing Epstein-Barr virus genomes.

We report a new and apparently unique human lymphoma cell line termed Deglis. The line was established from a polymorphic centroblastic lymphoma. The cell line and its source carry a dual B-cell and T-cell phenotype and Epstein-Barr virus (EBV) genomes. Simultaneous expression of B-cell (CD19+, CD20+, CD23+, CD37+) and T-cell (CD2+, CD3+/-, CD7+, CD43+) antigens, activation antigens (CD30+, CDw70+) as well as CD68+, a macrophage-associated antigen, was observed on the cell line and its source. Genotypic studies of the cell line showed dual gene rearrangements. JH (on both primary tumor and the cell line) and C kappa were rearranged without expression of cytoplasmic or surface immunoglobulins. T-cell receptor-alpha (TCR-alpha) and TCR-beta genes were rearranged, but TCR-delta and TCR-gamma genes were in germline configuration. Apparently, functional transcripts of TCR-alpha and truncated transcripts for TCR-beta and TCR-delta were observed. EBV-encoded proteins (LMP and EBNA2) were expressed by the parent tumor and the cell line. Southern blot analysis showed the same clonal EBV genomes in the primary tumor and the cell line. Karyotypic analysis of the cell line showed several chromosomal abnormalities but normal chromosomal number. The characteristics of this cell line suggest that neoplastic transformation has occurred in a precursor cell broadly committed to lymphoid lineage. Further studies on this cell line may help resolve some issues in the physiopathology of lymphoid tumors.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1998

Studies on Securigera securidacea (L.) Deg. et Dörfl. (Fabaceae) seeds, an antidiabetic Egyptian folk medicine.

A new cardenolide(-)-14-methoxy-rcanoside (1) was isolated from the aqueous extract of the seeds of Securigera securidacea (L.) Deg. et Dörfl. (Fabaceae) together with five new dihydrobenzofuran derivatives named securigran I-V (2-6). Kaempferol and astragalin were also isolated from the aqueous extract of the flowers. (-)-14-Methoxyhyrcanoside and the total aqueous extract of the seeds showed marked chronotropic activity. The total aqueous extract also showed a marked diuretic and severe hypokalemic effects on the K(+)-level in serum. The hypoglycemic effect of the seeds was also confirmed.

Animals↗
PubMed1978

Development of the filiform hairs on the cerci of Gryllus bimaculatus deg. (saltatoria, gryllidae).

The filiform hairs, mechanoreceptors of Gryllus, pass through six developmental stages during the last larval stage. The cytoplasm of their sense cells suggests intensive synthesis of protein for cellular metabolism and intercytoplasmic exchange of material via glial evaginations. Ultrahistochemical tests demonstrated acid phosphatase in the lysosomes as well as in components of the Golgi apparatus. There was no significant change in the appearance of the sense cell cytoplasm, indicating a maintained functional state also during molting. The new cuticular apparatus is formed after apolysis by the three enveloping cells. Formation of the replacement hairs is initiated by a cytoplasmic outgrowth of the trichogen cell. During morphogenesis of the new hair, the microtubules serve as a cytoskeleton and probably control the flow of vesicles, which contain phenol oxidase, also demonstrated in the Golgi apparatus, and are incorporated into the new cuticle. Bundles of microfibrils are involved in the surface sculpturing of the replacement hair. The trichogen cell also forms a number of structural elements, e.g. the "cup" and "strut" marked geometric peculiarities of which indicate that they are important in the spatial orientation of the dendrite and thus also in transduction. Reduction of the apical cell membrane of the tormogen cell after apolysis permits unrestricted growth of the new hair into the exuvial space. The tormogen cell participates in the formation of the joint membrane, parts of the socket and the articulation of the hair.

Acid Phosphatase↗
PubMed1996

The performance of SAPS II in a cohort of patients admitted to 99 Italian ICUs: results from GiViTI. Gruppo Italiano per la Valutazione degli interventi in Terapia Intensiva.

OBJECTIVE: To assess the validity of SAPS II (new Simplified Acute Physiology Score) in a cohort of patients admitted to a large sample of Italian intensive care units (ICU). DESIGN AND SETTING: The ability of the SAPS II scoring system to predict the probability of hospital mortality was assessed with calibration and discrimination measures obtained using published coefficients. A new logistic regression equation was then developed and further formal calibration and discrimination measures were estimated for the customized model. PATIENTS: From the 2202 consecutive patients recruited during a 1-month period in 99 ICUs, a total of 1393 patients were included in this validation study. RESULTS: When the parameters based on the standard model were applied, the expected probability of mortality did not fit those actually observed in the cohort (p < 0.001), although it showed satisfactory discrimination (area under the receiver operating characteristic curve = 0.80). Such lack of fit yields an overall under prediction of mortality (observed/expected ratio = 1.14) that reflects a uniform pattern across a preselected set of subgroups. Customization allowed new mortality estimates to be calculated, with satisfactory calibration (p = 0.82) and a more uniform pattern across subgroups. CONCLUSIONS: SAPS II maintained its validity in an independent sample of patients recruited in a large network of Italian ICUs only after appropriate adaptation (first-level customization). Whether the determinants of this relatively poor performance are related to differences in unmeasured case-mix, methods of application, or quality of care delivered is a matter for discussion that cannot be solved with the data presently available. However, these findings suggest that caution is warranted before implementing the standard SAPS II scoring system parameters outside formal research projects.

APACHE↗
PubMed2003

Establishment of the new genus Paranosema based on the ultrastructure and molecular phylogeny of the type species Paranosema grylli Gen. Nov., Comb. Nov. (Sokolova, Selezniov, Dolgikh, Issi 1994), from the cricket Gryllus bimaculatus Deg.

The ultrastructure of the microsporidian parasite Nosema grylli, which parasitizes primarily fat body cells and haemocytes of the cricket Gryllus bimaculatus (Orthoptera, Gryllidae) is described. All observed stages (meront, meront/sporont transitional stage ("second meront"), sporont, sporoblast, and spore) are found in direct contact with the host cell cytoplasm. Nuclei are diplokaryotic during almost all stages of the life cycle, but a brief stage with one nucleus containing an abundance of electron-dense material is observed during a "second merogony." Sporogony is disporous. Mature spores are ovocylindrical in shape and measure 4.5+/-0.16micromx2.2+/-0.07 microm (n=10) on fresh smears and 3.3+/-0.06 micromx1.4+/-0.07 microm (n=10) on ultrathin sections. Spores contain 15-18 coils of an isofilar polar filament arranged in one or two layers. Comparative phylogenetic analysis using rDNA shows N. grylli to be closely related to another orthopteran microsporidian, Nosema locustae, and to Nosema whitei from the confused flour beetle, Tribolium confusum. Antonospora scoticae, a parasite of the communal bee Andrena scotica, is a sister taxon to these three Nosema species. The sequence divergence and morphological traits clearly separate this group of "Nosema" parasites from the "true" Nosema clade containing Nosema bombycis. We therefore propose to change the generic name of N. grylli and its close relative N. locustae to Paranosema n. comb. We leave N. whitei in former status until more data on fine morphology of the species are obtained.

Animals↗
PubMed1998

Predicting outcome in the intensive care unit using scoring systems: is new better? A comparison of SAPS and SAPS II in a cohort of 1,393 patients. GiViTi Investigators (Gruppo Italiano per la Valutazione degli interventi in Terapia Intensiva). Simplified Acute Physiology Score.

OBJECTIVES: This study sought to compare the performance of the old and new versions of the Simplified Acute Physiology Score, SAPS and SAPS II, in classifying patients according to the risk of hospital mortality. METHODS: To compare the performance of the two systems, measures of association between the scores and observed mortality were adopted, together with discrimination (area under the Receiver Operating Characteristics curve) and calibration (goodness-of-fit statistics) estimates. Subjects were 1,393 eligible patients recruited during 1 month in 1994. The outcome measure was vital status at hospital discharge. RESULTS: SAPS II was associated more strongly with hospital mortality than the earlier version. SAPS II also had better discrimination ability than SAPS (area under Receiver Operating Characteristics curve 0.80 versus 0.74) and predicted an overall number of deaths (416.5) closer to the observed figure (475) than SAPS (267.7). Conversely, neither SAPS nor SAPS II fitted our data. Both P values derived from goodness-of-fit statistics were lower than 0.05. CONCLUSIONS: SAPS II offers a real improvement compared with SAPS in its ability to explain hospital mortality, but its standard parameters do not fit our data from Italy. The role and impact of potential determinants of this lack of fit, such as random errors and confounders related to casemix and/or quality of care should be clarified before this scoring system be used outside formal research projects. Special caution is suggested when SAPS II is adopted to predict mortality to compare intensive care unit performance across different countries and systems of care.

Adult↗
PubMed1995

Establishment and Characterization of an Anaerobic Thermophilic (55(deg)C) Enrichment Culture Degrading Long-Chain Fatty Acids.

A thermophilic, long-chain fatty acid-oxidizing culture was enriched. Stearate was used as the substrate, and methane and carbon dioxide were the sole end products. Cultivation was possible only when a fed-batch system was used or with addition of activated carbon or bentonite. The enrichment culture consisted of a short rod and two bacteria antigenically related to Methanobacterium thermoautotrophicum (Delta)H and Methanosarcina thermophila TM-1.

Journal Article↗