129 research outputs found
Antiproton stopping power in hydrogen below 120 keV and the Barkas effect
The simultaneous measurement of the spatial coordinates and times of p¯s annihilating at rest in a H2 target at very low density ρ (ρ/ρ0<10-2, ρ0 being the STP density) gives the possibility of evaluating the behavior of the p¯ stopping power in H2 at low energies (below 120 keV). It is different from that of protons (the Barkas effect). Moreover, it is shown that a rise at low-energy values (≲1 keV) is needed to agree with experimental data
Learning to live together: mutualism between self-splicing introns and their hosts
Group I and II introns can be considered as molecular parasites that interrupt protein-coding and structural RNA genes in all domains of life. They function as self-splicing ribozymes and thereby limit the phenotypic costs associated with disruption of a host gene while they act as mobile DNA elements to promote their spread within and between genomes. Once considered purely selfish DNA elements, they now seem, in the light of recent work on the molecular mechanisms regulating bacterial and phage group I and II intron dynamics, to show evidence of co-evolution with their hosts. These previously underappreciated relationships serve the co-evolving entities particularly well in times of environmental stress
Phase I Trial of Arginine Deprivation Therapy with ADI-PEG 20 Plus Docetaxel in Patients with Advanced Malignant Solid Tumors
PURPOSE: This phase I study examined the toxicity and tolerability, of pegylated arginine deiminase (ADI-PEG 20) in combination with docetaxel in patients with advanced solid malignancies. EXPERIMENTAL DESIGN: Eligible patients had histologically proven advanced solid malignancies, with any number of prior therapies, zubrod performance status 0–2 and adequate organ function. Patients received ADI-PEG 20 weekly intramuscular injection ranging from 4.5–36 mg/m(2), and up to ten doses of docetaxel 75 mg/m(2) every three weeks. Primary endpoints were safety, toxicity and a recommended phase II dose. Circulating arginine levels were measured prior to each cycle. Tumor response was measured as a secondary endpoint every six weeks on study. RESULTS: Eighteen patients received a total of 116 cycles of therapy through four dose levels of ADI-PEG 20. A single dose-limiting toxicity (grade 3 urticarial rash) was observed at the 1(st) dose level, with no additional dose-limiting toxicities observed. Hematologic toxicities were common with 14 patients experiencing at least one grade 3–4 leukopenia. Fatigue was the most prevalent toxicity reported by 16 patients. Arginine was variably suppressed with ten patients achieving at least a 50% reduction in baseline values. In 14 patients with evaluable disease, four partial responses (including two patients with PSA response) were documented and seven patients had stable disease. CONCLUSIONS: ADI-PEG 20 demonstrated reasonable toxicity in combination with docetaxel. Promising clinical activity was noted and expansion cohorts are now accruing for both castrate resistant prostate cancer and non-small cell lung cancer at a recommended phase II dose of 36 mg/m(2)
mRNA Secondary Structures Fold Sequentially But Exchange Rapidly In Vivo
Self-cleavage assays of RNA folding reveal that mRNA structures fold sequentially in vitro and in vivo, but exchange between adjacent structures is much faster in vivo than it is in vitro
Mobile DNA elements in T4 and related phages
Mobile genetic elements are common inhabitants of virtually every genome where they can exert profound influences on genome structure and function in addition to promoting their own spread within and between genomes. Phage T4 and related phage have long served as a model system for understanding the molecular mechanisms by which a certain class of mobile DNA, homing endonucleases, promote their spread. Homing endonucleases are site-specific DNA endonucleases that initiate mobility by introducing double-strand breaks at defined positions in genomes lacking the endonuclease gene, stimulating repair and recombination pathways that mobilize the endonuclease coding region. In phage T4, homing endonucleases were first discovered as encoded within the self-splicing td, nrdB and nrdD introns of T4. Genomic data has revealed that homing endonucleases are extremely widespread in T-even-like phage, as evidenced by the astounding fact that ~11% of the T4 genome encodes homing endonuclease genes, with most of them located outside of self-splicing introns. Detailed studies of the mobile td intron and its encoded endonuclease, I-TevI, have laid the foundation for genetic, biochemical and structural aspects that regulate the mobility process, and more recently have provided insights into regulation of homing endonuclease function. Here, we summarize the current state of knowledge regarding T4-encoded homing endonucleases, with particular emphasis on the td/I-TevI model system. We also discuss recent progress in the biology of free-standing endonucleases, and present areas of future research for this fascinating class of mobile genetic elements
Reduced costs with bisoprolol treatment for heart failure - An economic analysis of the second Cardiac Insufficiency Bisoprolol Study (CIBIS-II)
Background
Beta-blockers, used as an adjunctive to diuretics, digoxin and angiotensin converting enzyme inhibitors, improve survival in chronic heart failure. We report a prospectively planned economic analysis of the cost of adjunctive beta-blocker therapy in the second Cardiac Insufficiency BIsoprolol Study (CIBIS II).
Methods
Resource utilization data (drug therapy, number of hospital admissions, length of hospital stay, ward type) were collected prospectively in all patients in CIBIS . These data were used to determine the additional direct costs incurred, and savings made, with bisoprolol therapy. As well as the cost of the drug, additional costs related to bisoprolol therapy were added to cover the supervision of treatment initiation and titration (four outpatient clinic/office visits). Per them (hospital bed day) costings were carried out for France, Germany and the U.K. Diagnosis related group costings were performed for France and the U.K. Our analyses took the perspective of a third party payer in France and Germany and the National Health Service in the U.K.
Results
Overall, fewer patients were hospitalized in the bisoprolol group, there were fewer hospital admissions perpatient hospitalized, fewer hospital admissions overall, fewer days spent in hospital and fewer days spent in the most expensive type of ward. As a consequence the cost of care in the bisoprolol group was 5-10% less in all three countries, in the per them analysis, even taking into account the cost of bisoprolol and the extra initiation/up-titration visits. The cost per patient treated in the placebo and bisoprolol groups was FF35 009 vs FF31 762 in France, DM11 563 vs DM10 784 in Germany and pound 4987 vs pound 4722 in the U.K. The diagnosis related group analysis gave similar results.
Interpretation
Not only did bisoprolol increase survival and reduce hospital admissions in CIBIS II, it also cut the cost of care in so doing. This `win-win' situation of positive health benefits associated with cost savings is Favourable from the point of view of both the patient and health care systems. These findings add further support for the use of beta-blockers in chronic heart failure
Characterization of the interaction between the HIV-1 Gag structural polyprotein and the cellular ribosomal protein L7 and its implication in viral nucleic acid remodeling
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