Note Sui Grani a Spighe Ramificate

Resumé

Chez les Blés branchus de l'espèce «turgidum» (Triticum turgidum compositum), il existe des sortes à thermostade plutôt froid (Blés d'hiver ou de semi-hiver) et des sortes à thermostade chaud, tièe ou «indifférent» (Blés de printemps).

Les Blés branchus de l'espèce «turgidum» apparaissent comme étant des plantes à photostade de jour long.

La plus ou moins grande rapidité de l'accomplissement du photostade, par rapport à la rapidité de l'assimilation des matières plastiques, détermine la structure, — non ramifiée ou ramifiée — de l'épi.     

Quantification of mRNA in Salmonella sp. seeded soil and chicken manure using magnetic capture hybridization RT-PCR

Direct quantification of mRNA from Salmonella sp. seeded for 1 h to soil and chicken manure was accomplished using magnetic capture hybridization as a purification technique. This detection strategy targeted the invA gene present in Salmonella sp. After cell lysis, phenol/chloroform purification and isopropanol precipitation, the RNA extract was combined with the hybridization probe conjugated to paramagnetic beads. After hybridization, the captured nucleic acids were released by denaturation and purified of contaminating DNA using DNase. The resulting RNA was of high purity and there was no need for dilution of the samples prior to RT-PCR. The developed procedure was reproducibly used to quantify Salmonella sp. in high organic agricultural soil. The detection limit for mRNA using ordinary quantitative PCR (employing SYBRgreen-based detection) was 5 x 10(4)Salmonella sp. cells per gram of soil. Chicken manure amended into soil (1:4 w/w) did not reduce the ability to quantify Salmonella sp. mRNA in soil. Pasteurization (65 degrees C, 30 min) of chicken manure containing Salmonella sp. dramatically reduced the detection of invA mRNA (requiring 42 qPCR cycles for detection versus 26 cycles in unpasteurized manure), presumably due to degradation of the invA mRNA in Salmonella sp. cells killed by pasteurization. By contrast, DNA-based qPCR still detected Salmonella sp. in the pasteurized manure. Thus, in this case using samples seeded with fresh Salmonella sp. the mRNA-based detection appears to be superior to minimizing false-positive detection which was prevalent with DNA-based qPCR.     

Stent implantation in acute myocardial infarction using a heparin-coated stent: a pilot study as a preamble to a randomized trial comparing balloon angioplasty and stenting

Preliminary experience with primary stenting in myocardial infarction has suggested a greater benefit in clinical outcome than has been obtained with direct balloon angioplasty. However, subacute thrombosis (SAT) remains a limitation for this new mode of therapy. In the BENESTENT II Pilot and main trials, the incidence of SAT with the heparin-coated Palmaz-Schatz stent was only 0.15%. Therefore, as a preamble to a large randomized trial, the feasibility and safety of the use of the Heparin-Coated Palmaz-Schatz trade mark Stent in Acute Myocardial Infarction (AMI) was tested in 101 patients enrolled between April and September 1996 in 18 clinical centres. In 101 stent-eligible AMI patients, as dictated by protocol, a heparin-coated stent was implanted. The primary objectives were to determine the in-hospital incidence of major adverse cardiac events (MACE: death, MI, target lesion revascularization) and bleeding complications, while the secondary objectives were the procedural success rate and the MACE, the restenosis and reocclusion rates at 6.5 months. Stent implantation (n 3 129 stents) was successful in 97 patients of the 101 who were included in this trial. During their hospital stay, two patients died and no patient experienced re-infarction, ischaemia prompting re-PTCA or CABG. Four patients suffered a bleeding complication, three major and one minor, of whom three required surgical repair. At 210 days follow-up, 81% of the patients were event free. At 6.5 months restenosis was documented in 18% of the 88 patients who underwent follow-up angiography, including three total occlusions. The results, both with respect to QCA and the occurrence of MACE, compare favourably with studies using elective stenting in both stable and unstable angina patients. As a result of this pilot study, a large randomized trial comparing direct balloon angioplasty with direct stenting in 900 patients with AMI was initiated in December 1996.     

Evolution of the Adh locus in the Drosophila willistoni group: the loss of an intron, and shift in codon usage

We report here the DNA sequence of the alcohol dehydrogenase gene (Adh) cloned from Drosophila willistoni. The three major findings are as follows: (1) Relative to all other Adh genes known from Drosophila, D. willistoni Adh has the last intron precisely deleted; PCR directly from total genomic DNA indicates that the deletion exists in all members of the willistoni group but not in any other group, including the closely related saltans group. Otherwise the structure and predicted protein are very similar to those of other species. (2) There is a significant shift in codon usage, especially compared with that in D. melanogaster Adh. The most striking shift is from C to U in the wobble position (both third and first position). Unlike the codon-usage-bias pattern typical of highly biased genes in D. melanogaster, including Adh, D. willistoni has nearly 50% G + C in the third position. (3) The phylogenetic information provided by this new sequence is in agreement with almost all other molecular and morphological data, in placing the obscura group closer to the melanogaster group, with the willistoni group farther distant but still clearly within the subgenus Sophophora.      

Comparison of CA 15-3 and CEA in diagnosis and monitoring of breast cancer

In order to assess the utility of the tumor-associated antigen CA15-3 in the diagnosis of breast cancer, this new tumor marker was measured pre-operatively in 1342 patients. This group comprised 509 patients with malignant disease (134 with breast cancer and 375 with other malignancies not involving the breast) and 833 patients with benign surgical diseases (95 patients with fibroadenoma of the breast, 738 with other benign diseases). The results were compared with those for carcino-embryonic antigen (CEA) in the diagnosis of breast cancer. CA15-3 was above the normal limits of 25 U/ml in 31% of the patients with breast cancer, in 22% of patients with other malignancies, and in 9% of patients with benign diseases. CEA was elevated in 26% of patients with breast cancer (greater than 3 ng/ml). CA15-3 levels were above 50 U/ml in 13% of the breast cancer patients, in 6% of patients with other malignancies, and in 0.2% of the patients with benign diseases. There was a good correlation between CA15-3 level and tumor stage in breast cancer. CA15-3 serum levels were over 50 U/ml in respectively 0%, 2%, 13%, and 73% of the patients with stages I, II, III, and IV. CA15-3 and CEA were also determined in 671 patients who had received initial curative surgery of breast cancer, and who regularly attended our follow-up clinic. CA15-3 was found to be more sensitive than CEA in detecting recurrences of breast cancer.(ABSTRACT TRUNCATED AT 250 WORDS)     

Transcription dynamics of the functional tfdA gene during MCPA herbicide degradation by Cupriavidus necator AEO106 (pRO101) in agricultural soil

A modified protocol for simultaneous extraction of RNA and DNA, followed by real-time polymerase chain reaction quantification, was used to investigate tfdA gene expression during in situ degradation of the herbicide MCPA (4-chloro-2-methylphenoxy-acetic acid) in soil. tfdA encodes an alpha-ketoglutarate-dependent dioxygenase catalysing the first step in the degradation pathway of MCPA and 2,4-D (2,4-dichlorophenoxy-acetic acid). A linear recovery of tfdA mRNA over three orders of magnitude was shown, and the tfdA mRNA level was normalized using the tfdA mRNA/DNA ratio. The density of active cells required for tfdA mRNA detection was 10(5) cells g(-1) soil. Natural soil microcosms inoculated with Cupriavidus necator (formerly Ralstonia eutropha) AEO106 (pRO101) cells were amended with four different MCPA concentrations (2, 20, 50 and 150 mg kg(-1)). Mineralization rates were estimated by quantification of 14CO2 emission from degradation of 14C-MCPA. tfdA mRNA was detected 1 h after amendment at all four concentrations. In soils amended with 2 and 20 mg kg(-1), the mRNA/DNA ratio for tfdA demonstrated a sharp transient maximum of tfdA expression from no to full expression within 3 and 6 h respectively, followed by a decline and complete loss of expression after 19 and 43 h. A more complex pattern of tfdA expression was observed for the higher 50 and 150 mg kg(-1) amendments; this coincided with growth of C. necator AEO106 (pRO101) in the system. Repeated amendment with MCPA after 2 weeks in the 20 mg kg(-1) scenario revealed a sharp increase of tfdA mRNA, and absence of a mineralization lag phase. For all amendments, tfdA mRNA was detectable only during active mineralization, and thus revealed a direct correlation between tfdA mRNA presence and microbial degrader activity. The present study demonstrates that direct analysis of functional gene expression dynamics by quantification of mRNA can indeed be made in natural soil.     

Inline characterization of cell concentration and cell volume in agitated bioreactors using in situ microscopy: application to volume variation induced by osmotic stress

A new in situ microscope (ISM) was developed and tested to perform in-line monitoring of average cell volume and cell concentration in agitated cultures subjected to osmotic stress. The ISM is directly immersed into the agitated broth in a bioreactor and generates still images of cells by using pulsed luminescent diode illumination and a virtual probe volume defined by depth of focus. This technique allows the acquisition of microscopic still images without mechanical sampling techniques. The front end of the sensor fits into a standard 25-mm port and it can be steam sterilized together with the bioreactor. The automatic image evaluation generates signals of the cell concentration and the average cell volume with a time resolution of a few minutes per data point (if a 200 MHz PC is used). Without the need for evaluation, the images can be acquired and stored at a rate of one image per 0.6 s. Hansenula anomala was cultivated as batch fermentation and monitored inline with the ISM. The ISM signal of the cell concentration agreed well with referential growth curves that were obtained from counting with a hemocytometer. The ISM signal of the average cell volume shows a gradual volume reduction as a result of the aging of the culture, and it monitors an abrupt and strong cell contraction if osmotic shocks are generated in the bioreactor. Systematic in vitro studies of osmotic shocks were performed by applying the ISM to agitated culture samples of H. anomala. The volume signal of H. anomala during osmotic shocks showed a very fast cell contraction within less than a second. Within half an hour after the shocks, no signal drifts were observed, which would indicate volume restoration. These findings suggest that the ISM volume signal can be used as an inline indicator of osmotic stress in cell cultures.