Stabilization vs. destabilization of G-quadruplex superstructures: the role of the porphyrin derivative having spermine arms

The interaction of the porphyrin derivative H₂TCPPSpm4, having spermine pendants in the four meso positions, with the G-quadruplex (GQ) structure formed by the DNA aptamer TGGGAG has been investigated by means of UV, electronic circular dichroism and PAGE studies. The results reported here demonstrate that the porphyrin derivative is capable of stabilizing or destabilizing the higher-ordered structures of parallel GQs, depending on the method used to reach their relative stoichiometry (titration vs. single addition). Noteworthily, when two equivalents of H₂TCPPSpm4 were mixed directly with one equivalent of the (TGGGAG)₄ GQ to reach a 2 : 1 H₂TCPPSpm4 : GQ ratio T_1/2 higher than 80 °C was also observed confirming the presence of higher-ordered GQ structures.

Vortexes tune the chirality of graphene oxide and its non-covalent hosts

The ability of vortexes to tune the chirality of graphene oxide in water sheds light on its complex supramolecular organization allowing for selective noncovalent deposition of a predetermined handedness on a solid surface.

A controlled trial of Partners in Dementia Care: veteran outcomes after six and twelve months

Introduction

“Partners in Dementia Care” (PDC) tested the effectiveness of a care-coordination program integrating healthcare and community services and supporting veterans with dementia and their caregivers. Delivered via partnerships between Veterans Affairs medical centers and Alzheimer’s Association chapters, PDC targeted both patients and caregivers, distinguishing it from many non-pharmacological interventions. Hypotheses posited PDC would improve five veteran self-reported outcomes: 1) unmet need, 2) embarrassment about memory problems, 3) isolation, 4) relationship strain and 5) depression. Greater impact was expected for more impaired veterans. A unique feature was self-reported research data collected from veterans with dementia.

Methods and Findings

Five matched communities were study sites. Two randomly selected sites received PDC for 12 months; comparison sites received usual care. Three structured telephone interviews were completed every 6 months with veterans who could participate.

Results

Of 508 consenting veterans, 333 (65.6%) completed baseline interviews. Among those who completed baseline interviews, 263 (79.0%) completed 6-month follow-ups and 194 (58.3%) completed 12-month follow-ups. Regression analyses showed PDC veterans had significantly less adverse outcomes than those receiving usual care, particularly for more impaired veterans after 6 months, including reduced relationship strain (B = −0.09; p = 0.05), depression (B = −0.10; p = 0.03), and unmet need (B = −0.28; p = 0.02; and B = −0.52; p = 0.08). PDC veterans also had less embarrassment about memory problems (B = −0.24; p = 0.08). At 12 months, more impaired veterans had further reductions in unmet need (B = −0.96; p < 0.01) and embarrassment (B = −0.05; p = 0.02). Limitations included use of matched comparison sites rather than within-site randomization and lack of consideration for variation within the PDC group in amounts and types of assistance provided.

Conclusions

Partnerships between community and health organizations have the potential to meet the dementia-related needs and improve the psychosocial functioning of persons with dementia.

Trial Registry

NCT00291161

Plasmid-dependent co-mutation in Streptomyces coelicolor A3(2)

A spontaneous chromosomalmutation(plc A(-)) in Streptomyces coelicolor A3(2) made the inborn plasmid SCP1 susceptible to curing by UV irradiation. Lack of the SCP1 plasmid (in SCP1(-) strains) prevented the occurrence of the co-mutation process after MNNG treatment, although it left the susceptibility to the lethal effect of the mutagen virtually unaffected. SCP1(-) strains were, however, ultrasensitive to the lethal effect of UV. Curing a plc A(-) strain of its SCPI plasmid made it refractory to co-mutation by MNNG and sensitive to the lethal effect of UV; reinfected by the plasmid, the strain resumed both the co-mutation proficiency and the UV-resistance. The occurrence on the SCP1 plasmid of a gene comparable to the uvrE gene of E. coli (Nevers and Spatz 1975) was assumed.

Caregiver outcomes of partners in dementia care: effect of a care coordination program for veterans with dementia and their family members and friends

The objective is to test the effectiveness of Partners in Dementia Care (PDC), a care-coordination program that integrates and improves access to medical and nonmedical services, while strengthening the informal care network and providing information, coaching, and emotional support. PDC was delivered via a partnership between Veterans Affairs (VA) Medical Centers (VAMCs) and Alzheimer's Association chapters, for caregivers of veterans with dementia living in the community and receiving primary care from the VA. The initial sample was 486 caregivers of 508 veterans with diagnosed dementia. Outcomes were evaluated for 394 and 324 caregivers who completed 6- and 12- month follow-up, respectively. PDC had a standardized protocol that included assessment and reassessment, action planning, and ongoing monitoring. It was delivered by telephone and e-mail for cost efficiency and the ability to handle caseloads of 100 to 125. Care coordinators from VAMCs and Alzheimer's Association chapters worked as a team using a shared computerized record. A variety of caregiver outcomes was measured after 6 and 12 months. Intervention group caregivers had significant improvements in outcomes representing unmet needs, three types of caregiver strains, depression, and two support resources. Most improvements were evident after 6 months, with more-limited improvements from Months 6 to 12. Some outcomes improved for all caregivers, whereas some improved for caregivers experiencing more initial difficulties or caring for veterans with more-severe impairments. PDC is a promising model that improves linkages between healthcare services and community services, which is a goal of several new national initiatives such as the National Plan to Address Alzheimer's Disease and a proposed amendment to the Older Americans Act.

Renal pelvic cancer: a review of 611 patients treated in Illinois 1975-1985. Cancer Incidence and End Results Committee

Renal pelvic transitional cell carcinoma constitutes about 7 percent of all kidney cancer. This report is a summary of 611 Illinois patients with this tumor treated between 1975 and 1985. Overall, the five-year relative survival rate was 62 percent and the observed five-year rate was 48 percent. Stage was a major determinant of survival, as expected, in these cancer patients. The Illinois experience is reviewed and compared with the accumulated literature experience with renal pelvic cancers since 1944.

Renal pelvic transitional cell carcinoma. The role of the kidney in tumor-node-metastasis staging

Renal pelvic carcinoma is a rare tumor. There are several staging systems currently in use based on a bladder cancer staging model. An analysis of the American Cancer Society, Illinois Division, experience with 611 cases of renal pelvic transitional cell carcinoma suggested that the kidney parenchyma may be a determinant in the anatomic spread of disease. A tumor-node-metastasis system for renal pelvic (separate from ureteral) cancer is recommended.

Cytogenetic manifestations associated with the reversion, by gene amplification, at the HGPRT locus in V79 Chinese hamster cells

Some HGPRT spontaneous revertants were isolated from a mutant line (E2) of V79 Chinese hamster cells and phenotypically characterized. Dot-Blot hybridization with a 32P-labelled HGPRT probe revealed an increase in the number of HGPRT sequences in some of these revertants, suggesting the occurrence of gene amplification. Cytogenetic analysis performed in three of these revertants showed a characteristic abnormally banding region (ABR) on the elongated p arm of the X chromosome. In situ hybridization in one revertant (RHE2) showed that the amplified sequences reside on the p+ arm of the X chromosome in two different localizations. Because of the very probably clonal origin of the revertant, these features indicate that the amplified sequences might rearrange after their integration into the chromosome.

Chromosome aberrations associated with CAD gene amplification in Chinese hamster cultured cells

Eleven sublines with increasing resistance to N-phosphonacetyl-L-aspartate (PALA) were isolated from the V79,B7 Chinese hamster cell line. Aspartate transcarbamylase activity and CAD gene copy number increased with increasing resistance of sublines. In situ hybridization with a DNA probe for the CAD gene showed that the amplified sequences resided in the terminal region of a marker chromosome with elongated q arms. This region stained homogeneously after G-banding. A high incidence of both numerical and structural chromosome aberrations was found in PALA-resistant cells. In hyperdiploid and polyploid cells, containing 2 copies of the marker chromosome, dicentrics were found at a very high frequency. As indicated by in situ hybridization and G-banding, they originated from a rearrangement involving 2 homologous marker chromosomes.

Anti-inflammatory drugs in experimental atherosclerosis. Part 5. Influence of cortisone acetate on short-term and long-term cholesterol fluxes in atherosclerotic aorta

Previous studies in this series have shown that cortisone and other anti-inflammatory drugs inhibit atherosclerotic plaque development in cholesterol-fed rabbits. The present study was designed to investigate the influence of cortisone on the processes of cholesterol influx and efflux in the aorta wall. Forty-seven New Zealand white rabbits were fed a 1% cholesterol diet for periods up to 12 weeks. In addition 23 of the animals were fed 5 mg cortisone acetate daily. At 0, 5 and 12 weeks, groups were fed a tracer dose of [3H]cholesterol. Plasma cholesterol specific radioactivity was measured at intervals during the next 10 days. Total aorta cholesterol and its specific activity were measured by killing groups of animals at 2 days and 10 days. Atherosclerotic plaque intensity at 12 weeks, measured planimetrically, averaged 68 +/- 12% in controls vs. only 6 +/- 3% in cortisone-treated animals. During the period between 5 and 12 weeks, net cholesterol accumulation by chemical analysis averaged only 11 micrograms/g aorta/day in cortisone-treated animals vs. 117 micrograms/g in controls. [3H]cholesterol influx (measured during a brief 2-day exposure) at 5 weeks averaged 206 and 199 micrograms/g tissue/day and at 12 weeks 586 micrograms and 281 micrograms/day in control and cortisone-treated animals, respectively. Measured over a longer 10-day period, however, the apparent influx of [3H]cholesterol was much less in cortisone-treated animals, averaging only 53 micrograms/day compared to 269 micrograms/day in controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Instantaneous renal arterial pressure-flow relations in anesthetized dogs

Instantaneous renal arterial pressure-flow (P/ Qra ) relations were investigated in 11 anesthetized dogs using the nonpulsatile fall in aortic pressure and renal arterial flow ( Qra ) during cardiac arrest caused by vagal stimulation. We found that P/ Qra relations were linear with an extrapolated zero flow intercept (Ped, effective downstream pressure) of 20.8 +/- 1.9 mmHg and the reciprocal of the slope (Ra, arterial resistance) of 0.6 +/- 0.04 mm Hg X ml-1 X min. These values are markedly lower than the values found in similar experiments in coronary and femoral arteries. Raising renal venous pressure (5 dogs) decreased Qra and elevated Ra and Ped in the ipsilateral renal artery while decreasing Qra and elevating Ra but not Ped in the contralateral renal artery. Carotid artery occlusion (6 dogs) decreased Qra and elevated Ra and Ped. Alpha-Adrenergic blockade (4 dogs) lowered Ped and Ra. Arterial resistance seems to be more important for change in P/Q relations in the renal arterial bed than it is in other arterial beds investigated so far. We suggest that the effective downstream pressure to renal arterial flow is downstream from the glomerular capillaries. The location of the "vascular waterfall " phenomenon appears to be between the intrarenal veins and the veins outside the capsule.

Recovery of V79 cell clones with different phenotypes in aminopterin- or azaserine-containing media used for the selection of HGPRT revertants

Three 6-thioguanine (6TG)-resistant mutants were mutagen-treated and selected for clones capable of growing in 2 selective media: HAT medium, containing aminopterin (AP) and HAS medium, containing L-azaserine (AS). Both 6TG-sensitive, wild-type clones and 6TG-resistant mutants were found among colonies growing in HAT medium, while only 6TG-sensitive clones grew in HAS medium. Time for expression was required by 6TG-resistant but not by 6TG-sensitive clones, that were fully expressed immediately after treatment. All HAT-resistant, 6TG-resistant clones which were analyzed proved to be resistant to AP. These data were interpreted as follows: in HAT medium, both HGPRT+ revertants and double mutants (HGPRT-, AP-resistant) were selected, while only HGPRT+ revertants were selected in HAS medium. Not all 6TG-resistant mutants were able to produce both classes of HAT-resistant clones.

Selection in HAT medium is not a reliable method for the study of reversion from 6-thioguanine resistance to sensitivity

6-Thioguanine-resistant mutants were induced in V79 Chinese hamster cells with 2-aminopurine, ICR-170 and hycanthone. Samples of mutants of different origin were treated with EMS or 1CR-170 and plated in HAT medium for selection of revertants. In the result, a significant fraction of HAT-resistant clones was not 6-thioguanine-sensitive as would have been expected from a genuine reversion to wild type.

Mutagenicity of halogenated aliphatic hydrocarbons in Salmonella typhimurium, Streptomyces coelicolor and Aspergillus nidulans

Eight structurally related halogenated aliphatic hydrocarbons mono-, di- and trichloroacetaldehyde (the last in the anhydrous and hydrate form), moni-, di- and trichloroethanol and allyl chloride, were tested for their ability to induce gene mutations in prokaryotic and eukaryotic microorganisms. The genetic systems employed were the Salmonella reversion test with strain TA1535 and TA100, with and without metabolic activation, a forward and a back-mutation system in S. coelicolor and two forward mutation systems in A. nidulans. Each compound was tested with the spot and plate incorporation assay techniques. Mono-, di- and trichloroacetaldehyde were mutagenic in all the microorganisms employed; all the halogenated ethanols were positive in A. nidulans, while in S. typhimurium and in S. coelicolor the only active forms were respectively the mono- and dichloroderivatives. Allyl chloride was active in S. typhimurium and S. coelicolor and negative in A. nidulans. The technical approach as well as the complex influence of different factors (toxicity, volatility and stability) on the genetic response of each of the compounds under test did not allow to obtain more than a qualitative relationship between mutagenic potency and chemical structure.

Anti-inflammatory agents in experimental atherosclerosis. Part 2. Failure of antihypertensive drugs to exacerbate atherosclerotic plaque formation

Hypertension is associated with an increased incidence of generalized vascular disease. Antihypertensive drug therapy, while decreasing overall mortality due to cerebral hemorrhage, myocardial hypertrophy or renal failure, paradoxically does not appear to reduce the incidence of coronary atherosclerosis. This study investigates whether the drugs, as a possible side effect, may have an adverse influence on the development of atherosclerotic plaques. Groups of rabbits were fed an atherogenic diet containing 1% cholesterol for 12 weeks. Two commonly used antihypertensive agents (methyldopa and chlorthalidone) were added to the diet of some groups at levels of 100 mg and 10 mg per day respectively. No significant increase in total atherosclerotic plaque area was produced by either of the drugs tested singly or in combination. Plasma renin levels were only mildly elevated and in this experimental system there was no correlation between renin activity and atherosclerotic plaque intensity. There is thus no evidence from this study that antihypertensive drugs have any adverse effects on atherosclerotic plaque formation. While the ineffectiveness of these drugs against coronary atherosclerosis may indicate that normalization of pressure cannot arrest changes already initiated, it also supports the possibility that association of atherosclerosis with hypertension may be symptomatic of a common underlying defect not correlated by normalizing blood pressure.

Localized mutagenesis in Streptomyces coelicolor A3 (2)

Nutritional mutants (co-mutants) were scored among nitrosoguanidine-induced revertants of four mutations in Streptomyces coelicolor A3 (2). All co-mutations were due to mutations in genes linked to the revertant locus. The co-mutant loci were located in a region of about 20 map units around the revertant locus (co-mutation region). Revertants for different loci showed co-mutation patterns different from each other and from that of random nitrosoguanidine-induced forward mutations. Mutations appeared to be completely abolished outside the co-mutation region (mutation restriction).

Comutation in Streptomyces

Up to 6% of N-methyl-N'-nitro-N-nitrosoguanidine-induced back mutations in the hisA locus of Streptomyces coelicolor were forward mutations (comutations) in another closely linked his locus.