Experimental observations of soliton wave trains in electron beams

The first experimental observation of a Korteweg-de Vries-type soliton wave train in intense electron beams is reported. A narrow, large-amplitude perturbation on a long-pulse beam is observed to steepen and spawn a soliton wave train. The pulse width and amplitude of each peak remain unchanged over a long propagation distance, and the amplitude is inversely proportional to the square of the width. Two such pulses are seen to pass through each other, emerging from the collision unchanged. The experimental results are reproduced by particle-in-cell simulations.

Simian virus 40-, but not human papillomavirus-, transformation of prostatic epithelial cells results in loss of growth-inhibition by 1,25-dihydroxyvitamin D-3

In addition to its well known calcemic actions, 1,25-dihydroxyvitamin D-3 [1,25(OH)(2)D] exhibits differentiating and antiproliferative effects in several types of cancer cells. 1,25(OH)(2)D receptors (VDR) as well as 1,25(OH)(2)D-mediated growth-inhibition have been demonstrated in human prostate cancer cell lines. In order to further develop model systems for the study of 1,25(OH)(2)D action and to elucidate the mechanism of growth-inhibition, we studied several human prostate cell lines immortalized with either simian virus 40 (SV40) or human papillomavirus type 18 (HPV). The SV40-transformed cell lines P69SV40-T and P153SV40-T were not growth-inhibited by 1,25(OH)(2)D at concentrations as high as 100 nM, whereas the HPV-transformed cells PZ-HPV-7 and CA-HPV-10 were growth-inhibited. All cell lines expressed VDR, and VDR mRNA was demonstrated by Northern blot analysis. All cells exhibited induction of 24-hydroxylase mRNA, a 1,25(OH)(2)D responsive gene, after 1,25(OH)(2)D treatment. In an attempt to understand the apparent dissociation of 1,25(OH)(2)D actions in the SV40-transformed cells, we turned to the human prostate cancer cell line DU 145. These cells, like the SV40-transformed cells, are not growth-inhibited but demonstrate induction of 24-hydroxylase mRNA after 1,25(OH)(2)D treatment. DU 145 cells contain a mutated retinoblastoma gene (Rb) which contributes to their uncontrolled growth, analogous to the disruption of Rb by SV40 and HPV. We compared DU,145 cells to DU 145 cells transfected with normal Rb (DU 145/Rb). Similar to DU 145, DU 145/Rb cells were not growth-inhibited by 1,25(OH)(2)D, while 24-hydroxylase mRNA was induced. These results suggest that divergent pathways mediate the growth-inhibitory effect of 1,25(OH)(2)D and its induction of 24-hydroxylase. It also appears that the antiproliferative effect of 1,25(OH)(2)D is mediated by an Rb-independent mechanism.

Mixed methods study of management of health conditions in rural low-income families: implications for health care policy in the USA

INTRODUCTION

The purpose of this mixed methods study was to examine the health issues and health management strategies utilized by rural low-income women and their families to inform the design, implementation, and evaluation of health reform in rural areas of the USA. METHODS; Quantitative data was analyzed from 271 rural, low-income women and their families and qualitative data from a sub-sample of 44. Specifically explored were the: (1) types and perceived severity of health conditions rural, low-income individuals report; (2) perceived value and utilization of a usual source of care; and (3) strategies these individuals employ to manage their health.

RESULTS

Rural American families manage multiple healthcare needs with limited resources; 42.1% reported 1-4 chronic conditions in the family, 31.4% reported 5-8 conditions, and 17.7% reported 9 or more conditions. The majority of participants (79.0%) reported having a doctor or other healthcare professional that they usually see; 61.3% reported their partners had a usual provider, and 91.7% reported their children had a usual provider. Analysis of the qualitative data revealed two main themes regarding management of health conditions: (1) lack of engagement in managing overall health; and (2) ineffective utilization of health care.

CONCLUSIONS

Rural low-income individuals in the US may benefit from new policies that promote patient-centered, personalized care. However, any policy change must be carefully designed to consider the ways in which rural American families manage their health in order to improve individual health status and reduce rural health disparities.

Effect of nesiritide in patients with acute decompensated heart failure

BACKGROUND

Nesiritide is approved in the United States for early relief of dyspnea in patients with acute heart failure. Previous meta-analyses have raised questions regarding renal toxicity and the mortality associated with this agent.

METHODS

We randomly assigned 7141 patients who were hospitalized with acute heart failure to receive either nesiritide or placebo for 24 to 168 hours in addition to standard care. Coprimary end points were the change in dyspnea at 6 and 24 hours, as measured on a 7-point Likert scale, and the composite end point of rehospitalization for heart failure or death within 30 days.

RESULTS

Patients randomly assigned to nesiritide, as compared with those assigned to placebo, more frequently reported markedly or moderately improved dyspnea at 6 hours (44.5% vs. 42.1%, P=0.03) and 24 hours (68.2% vs. 66.1%, P=0.007), but the prespecified level for significance (P≤0.005 for both assessments or P≤0.0025 for either) was not met. The rate of rehospitalization for heart failure or death from any cause within 30 days was 9.4% in the nesiritide group versus 10.1% in the placebo group (absolute difference, -0.7 percentage points; 95% confidence interval [CI], -2.1 to 0.7; P=0.31). There were no significant differences in rates of death from any cause at 30 days (3.6% with nesiritide vs. 4.0% with placebo; absolute difference, -0.4 percentage points; 95% CI, -1.3 to 0.5) or rates of worsening renal function, defined by more than a 25% decrease in the estimated glomerular filtration rate (31.4% vs. 29.5%; odds ratio, 1.09; 95% CI, 0.98 to 1.21; P=0.11).

CONCLUSIONS

Nesiritide was not associated with an increase or a decrease in the rate of death and rehospitalization and had a small, nonsignificant effect on dyspnea when used in combination with other therapies. It was not associated with a worsening of renal function, but it was associated with an increase in rates of hypotension. On the basis of these results, nesiritide cannot be recommended for routine use in the broad population of patients with acute heart failure. (Funded by Scios; ClinicalTrials.gov number, NCT00475852.).

DDAVP responsiveness in children with mild or moderate haemophilia A correlates with age, endogenous FVIII:C level and with haemophilic genotype

In most individuals with moderate/mild haemophilia A, FVIII:C levels increase following DDAVP administration to a haemostatic range, thus avoiding the need for FVIII concentrates. We sought to determine the relationship between responsiveness to DDAVP in boys (<18 years old) with mild/moderate haemophilia and patient age, haemophilic severity and haemophilic genotype. Our cohort consisted of 13 boys with moderate and 61 boys with mild haemophilia who, between them, had 38 different mutations; 21 had unique mutations not shared by any other clinic patient, whereas 53 shared one of 17 mutations with some other clinic patient (included 26 boys with ≥ 1 haemophilic brother). Patient age and endogenous FVIII:C levels were strong predictors of response to DDAVP. Younger patients responded less well to DDAVP and 10 of the 11 patients, when retested at an older age, showed an improved response to DDAVP. Only 1 patient with moderate haemophilia responded to DDAVP, whereas 80% of patients with mild haemophilia responded (including all patients with an endogenous FVIII:C of >0.15 U mL(-1)). Almost all patients with the same mutation had the same response to DDAVP or only a minor discordance in response. Patient's age, disease severity and genotype all are predictors of response to DDAVP.

Search for inherited susceptibility to radiation-associated meningioma by genomewide SNP linkage disequilibrium mapping

Background:

Exposure to ionising radiation is a well-established risk factor for multiple types of tumours, including malignant brain tumours. In the 1950s, radiotherapy was used to treat Tinea Capitis (TC) in thousands of children, mostly of North-African and Middle Eastern origin, during the mass migration to Israel. The over-representation of radiation-associated meningioma (RAM) and other cancers in specific families provide support for inherited genetic susceptibility to radiation-induced cancer.

Methods:

To test this hypothesis, we genotyped 15 families segregating RAM using high-density single-nucleotide polymorphism (SNP) arrays. Using the family-based association test (FBAT) programme, we tested each polymorphism and haplotype for an association with RAM.

Results:

The strongest haplotype associations were attained at 18q21.1 (P=7.5 × 10⁻⁵), 18q21.31 (P=2.8 × 10⁻⁵) and 10q21.3 (P=1.6 × 10⁻⁴). Although associations were not formally statistically significant after adjustment for multiple testing, the 18q21.1 and 10q21.3 associations provide support for a variation in PIAS2, KATNAL2, TCEB3C, TCEB3CL and CTNNA3 genes as risk factors for RAM.

Conclusion:

These findings suggest that any underlying genetic susceptibility to RAM is likely to be mediated through the co-inheritance of multiple risk alleles rather than a single major gene locus determining radiosensitivity.

Morphology of Lignin-Polyurethane Blends

The morphology of blended polyurethane (PU) sealants was studied by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The PU was modifided by mechanical mixing with various amounts of Lignin (L) to achieve a homogeneous blend. Specimens were subjected to control (C), accelerated weathering (AW), and natural weathering (NW) conditions. Results obtained from SEM analysis reveal an even distribution of L particles in the PU matrix. Furthermore, the SEM photomicrographs clearly emphasize the differing morphologies of the constituent phases. They also depict the differences in surface texture between control and aged specimens. The DSC analysis shows that the two phases are immiscible which is in agreement with observations by microscopy.

Recycling Lignin for Engineering Applications

Lignin, a complex natural polymer produced by all vascular terrestrial plants is second in abundance only to cellulose and is the matrix holding plant fibres together. Lignins are recovered mainly as byproducts from woodpulping processes with about 100 million tons produced annually worldwide.

Large volume uses for lignin byproduct other than for generation of energy (kraft process) are most likely to be in materials applications.

In the last decades many studies aimed to the recycling of different lignins (sulfite, kraft, organosolv, steam exploded, hydrolytic, etc.) in polymeric systems based on thermoplastics, thermosettings, elastomers, adhesives, sealants, etc.

Among all the technical lignins, sulfate lignins are chemically the most reactive and are therefore used to modify polymers. The oldest and the most familiar application of lignin as a component of polymeric materials involves the reinforcement of rubber. Multicomponent materials can be created by combination with other macromolecules like polyethylene, polypropylene, or poly(vinyl alcohol) to produce polyblends, block copolymers or interpenetrating polymer networks.

The present communication will try to present such examples of polymeric systems based on recycled lignin, and synthetic polymers such as: polyurethane, epoxy, acrylics, silicones.

Photoprotection by 1alpha,25-dihydroxyvitamin D and analogs: further studies on mechanisms and implications for UV-damage

Ultraviolet (UV) irradiation causes DNA damage in skin cells, immunosuppression and photocarcinogenesis. 1alpha,25-dihydroxyvitamin D3 (1,25D) reduces UV-induced DNA damage in the form of cyclobutane pyrimidine dimers (CPD) in human keratinocytes in culture and in mouse and human skin. UV-induced immunosuppression is also reduced in mice by 1,25D, in part due to the reduction in CPD and a reduction in interleukin (IL-6. The cis-locked analog, 1alpha,25-dihydroxylumisterol3 (JN), which has almost no transactivating activity, reduces UV-induced DNA damage, apoptosis and immunosuppression with similar potency to 1,25D, consistent with a non-genomic signalling mechanism. The mechanism of the reduction in DNA damage in the form of CPD is unclear. 1,25D doubles nuclear expression of p53 compared to UV alone, which suggests that 1,25D facilitates DNA repair. Yet expression of a key DNA repair gene, XPG is not affected by 1,25D. Chemical production of CPD has been described. Incubation of keratinocytes with a nitric oxide donor, SNP, induces CPD in the dark. We previously reported that 1,25D reduced UV-induced nitrite in keratinocytes, similar to aminoguanidine, an inhibitor of nitric oxide synthase. A reduction in reactive nitrogen species has been shown to facilitate DNA repair, but in view of these findings may also reduce CPD formation via a novel mechanism.