Transient enhanced cell division by blocking DNA synthesis in .

Duplication of the bacterial nucleoid is necessary for cell division hence specific arrest of DNA replication inhibits divisions culminating in filamentation, nucleoid dispersion and appearance of a-nucleated cells. It is demonstrated here that during the first 10 min however, enhanced residual divisions: the proportion of constricted cells doubled (to 40%), nucleoids contracted and cells remodelled dimensions: length decreased and width increased. The preliminary data provides further support to the existence of temporal and spatial couplings between the nucleoid/replisome and the sacculus/divisome, and is consistent with the idea that bacillary bacteria modulate width during the division process exclusively.

Impact of anemia as risk factor for major bleeding and mortality in patients with acute coronary syndrome.

Background: Anemia is frequent in acute coronary syndrome (ACS) patients and is associated with worse clinical outcomes. We aimed to investigate the therapeutic strategies, the use of novel P2Y inhibitors, and the prognostic implication of anemia in a "real world" cohort of ACS patients.

Methods: This is an observational and prospective registry including 1717 ACS patients from three tertiary hospitals.

Thymineless Death Lives On: New Insights into a Classic Phenomenon.

The primary mechanisms by which bacteria lose viability when deprived of thymine have been elusive for over half a century. Early research focused on stalled replication forks and the deleterious effects of uracil incorporation into DNA from thymidine-deficient nucleotide pools. The initiation of the replication cycle and origin-proximal DNA degradation during thymine starvation have now been quantified via whole-genome microarrays and other approaches.

Thymineless death, at the origin.

Thymineless death (TLD) in bacteria has been a focus of research for decades. Nevertheless, the advances in the last 5 years, with Escherichia coli as the model organism, have been outstanding. Independent research groups have presented compelling results that establish that the initiation of chromosome replication under thymine starvation is a key element in the scenario of TLD.

Determination of the olive maturity index of intact fruits using image analysis.

In this work, the maturity index of different samples of olives was objectively assessed by image analysis obtained through machine vision, in which algorithms of color-based segmentation and operators to detect edges were used. This method allows a fast, automatic and objective prediction of olive maturity index. This prediction value was compared to maturity index (MI), generally used by olive oil industry, based on the subjective visual determination of color of fruit skin and flesh.

Comparing the implementation of team approaches for improving diabetes care in community health centers.

Background: Patient panel management and community-based care management may be viable strategies for community health centers to improve the quality of diabetes care for vulnerable patient populations. The objective of our study was to clarify implementation processes and experiences of integrating office-based medical assistant (MA) panel management and community health worker (CHW) community-based management into routine care for diabetic patients.

Methods: Mixed methods study with interviews and surveys of clinicians and staff participating in a study comparing the effectiveness of MA and CHW health coaching for improving diabetes care.

Evaluation of the overall quality of olive oil using fluorescence spectroscopy.

The fluorescence spectra of some olive oils were examined in their natural and oxidised state, with wavelength range emissions of 300-800 nm and 300-400 nm used as excitation radiation. The fluorescence emissions were measured and an assessment was made of the relationship between them and the main quality parameters of olive oils, such as peroxide value, K232, K270 and acidity. These quality parameters (peroxide value, K232, K270 and acidity) are determined by laboratory methods, which though not too sophisticated, they are required solvents and materials as well as time consuming and sample preparation; there is a need for rapid analytical techniques and a low-cost technology for olive oil quality control.

Rifampicin suppresses thymineless death by blocking the transcription-dependent step of chromosome initiation.

Thymineless death (TLD), a phenomenon in which thymine auxotrophy becomes lethal when cells are starved of thymine, can be prevented by the presence of rifampicin, an RNA polymerase inhibitor. Several lines of evidence link TLD to chromosome initiation events. This suggests that rifampicin-mediated TLD suppression could be due to the inhibition of RNA synthesis required for DNA chromosomal initiation at oriC, although other mechanisms cannot be discarded.

Infrared machine vision system for the automatic detection of olive fruit quality.

External quality is an important factor in the extraction of olive oil and the marketing of olive fruits. The appearance and presence of external damage are factors that influence the quality of the oil extracted and the perception of consumers, determining the level of acceptance prior to purchase in the case of table olives. The aim of this paper is to report on artificial vision techniques developed for the online estimation of olive quality and to assess the effectiveness of these techniques in evaluating quality based on detecting external defects.

Tuning the replication fork progression by the initiation frequency.

The thermo-resistant period of the thermo-sensitive ribonucleotide reductase RNR101 encoded by the nrdA101 allele in Escherichia coli is prolonged for 50 min at 42°C, enabling an increase in DNA content of about 45%. Assuming that fork progression in the nrdA101 mutant is impaired, the question whether reduced number of ongoing replication rounds altered the thermo-resistant period in this strain was investigated. Decreases in the oriC/terC ratio and in the number of oriC per cell at 30°C were found in the presence of oriC228, oriC229 and oriC239 alleles in strain nrdA101.

A portable Raman sensor for the rapid discrimination of olives according to fruit quality.

In the real marketplace, providing high-quality olive oil is important from the perspective of both consumers and producers. Quality control should meet all requirements in the production process, from farm to packaging. The quality of olive oil can be affected by several factors, including agricultural techniques, seasonal conditions, farming systems, maturity, method and duration of storage, and process technology.

Overlap of replication rounds disturbs the progression of replicating forks in a ribonucleotide reductase mutant of Escherichia coli.

Ribonucleotide reductase (RNR) is the only enzyme specifically required for the synthesis of deoxyribonucleotides (dNTPs). Surprisingly, Escherichia coli cells carrying the nrdA101 allele, which codes for a thermosensitive RNR101, are able to replicate entire chromosomes at 42 °C under RNA or protein synthesis inhibition. Here we show that the RNR101 protein is unstable at 42 °C and that its degradation under restrictive conditions is prevented by the presence of rifampicin.

RecA-dependent replication in the nrdA101(Ts) mutant of Escherichia coli under restrictive conditions.

Cells carrying the thermosensitive nrdA101 allele are able to replicate entire chromosomes at 42°C when new DNA initiation events are inhibited. We investigated the role of the recombination enzymes on the progression of the DNA replication forks in the nrdA101 mutant at 42°C in the presence of rifampin. Using pulsed-field gel electrophoresis (PFGE), we demonstrated that the replication forks stalled and reversed during the replication progression under this restrictive condition.

DNA replication initiation as a key element in thymineless death.

Thymine deprivation results in the loss of viability in cells from bacteria to eukaryotes. Numerous studies have identified a variety of molecular processes and cellular responses associated with thymineless death (TLD). It has been observed that TLD occurs in actively growing cells, and DNA damage and DNA recombination structures have been associated with cells undergoing TLD.

Double-strand break generation under deoxyribonucleotide starvation in Escherichia coli.

Stalled replication forks produced by three different ways of depleting deoxynucleoside triphosphate showed different capacities to undergo "replication fork reversal." This reaction occurred at the stalled forks generated by hydroxyurea treatment, was impaired under thermal inactivation of ribonucleoside reductase, and did not take place under thymine starvation.

Defective ribonucleoside diphosphate reductase impairs replication fork progression in Escherichia coli.

The observed lengthening of the C period in the presence of a defective ribonucleoside diphosphate reductase has been assumed to be due solely to the low deoxyribonucleotide supply in the nrdA101 mutant strain. We show here that the nrdA101 mutation induces DNA double-strand breaks at the permissive temperature in a recB-deficient background, suggesting an increase in the number of stalled replication forks that could account for the slowing of replication fork progression observed in the nrdA101 strain in a Rec(+) context. These DNA double-strand breaks require the presence of the Holliday junction resolvase RuvABC, indicating that they have been generated from stalled replication forks that were processed by the specific reaction named "replication fork reversal.

The synchrony phenotype persists after elimination of multiple GATC sites from the dnaA promoter of Escherichia coli.

To examine whether methylation of the GATC sites present in the dnaA promoter region is responsible for the strict temporal coordination of initiation events at oriC as measured by the synchrony of initiation, we introduced point mutations eliminating three (TGW1) and five (TGW2) of the six GATC sites present in the dnaA promoter region. All of the strains containing these mutations, including the one with five GATC sites eliminated, initiated chromosomal replication synchronously.

Escherichia coli cells with increased levels of DnaA and deficient in recombinational repair have decreased viability.

The dnaA operon of Escherichia coli contains the genes dnaA, dnaN, and recF encoding DnaA, beta clamp of DNA polymerase III holoenzyme, and RecF. When the DnaA concentration is raised, an increase in the number of DNA replication initiation events but a reduction in replication fork velocity occurs. Because DnaA is autoregulated, these results might be due to the inhibition of dnaN and recF expression.

Ribonucleoside diphosphate reductase is a component of the replication hyperstructure in Escherichia coli.

Although the nrdA101 allele codes for a ribonucleoside diphosphate (rNDP) reductase that is essentially destroyed in less than 2 min at 42 degrees C, and chemical inhibition of the enzyme by hydroxyurea stops DNA synthesis at once, we found that incubation at 42 degrees C of an Escherichia coli strain containing this allele allows DNA replication for about 40min. This suggests that mutant rNDP reductase is protected from thermal inactivation by some hyperstructure. If, together with the temperature upshift, RNA or protein synthesis is inhibited, the thermostability time of the mutant rNDP reductase becomes at least as long as the replication time and residual DNA synthesis becomes a run-out replication producing fully replicated chromosomes.