The prebiotic evolutionary advantage of transferring genetic information from RNA to DNA.

In the early 'RNA world' stage of life, RNA stored genetic information and catalyzed chemical reactions. However, the RNA world eventually gave rise to the DNA-RNA-protein world, and this transition included the 'genetic takeover' of information storage by DNA. We investigated evolutionary advantages for using DNA as the genetic material. The error rate of replication imposes a fundamental limit on the amount of information that can be stored in the genome, as mutations degrade information. We compared misincorporation rates of RNA and DNA in experimental non-enzymatic polymerization and calculated the lowest possible error rates from a thermodynamic model. Both analyses found that RNA replication was intrinsically error-prone compared to DNA, suggesting that total genomic information could increase after the transition to DNA. Analysis of the transitional RNA/DNA hybrid duplexes showed that copying RNA into DNA had similar fidelity to RNA replication, so information could be maintained during the genetic takeover. However, copying DNA into RNA was very error-prone, suggesting that attempts to return to the RNA world would result in a considerable loss of information. Therefore, the genetic takeover may have been driven by a combination of increased chemical stability, increased genome size and irreversibility

Comparing the effects of COX and non-COX-inhibiting NSAIDs on enhancement of apoptosis and inhibition of aberrant crypt foci formation in a rat colorectal cancer model

The protection against colorectal cancer (CRC) by non-steroidal anti-inflammatory drugs (NSAIDs) is in part dependent on inhibition of cyclooxygenase (COX). We compared the efficacy of the non-COX-inhibiting R flurbiprofen (R-FB) with COX-inhibiting sulindac and racemic flurbiprofen (Rac-FB), and determined their effects on apoptosis, in an azoxymethane (AOM)-induced rat CRC model. In experiment 1, groups of rats were given daily drug gavage (R-FB 30 mg/kg, Rac-FB 10 mg/kg and Sulindac 20 mg/kg) for one week, followed by AOM treatment and were killed eight hours later, colons were examined for apoptosis and cell proliferation. In experiment 2, groups of rats were given two AOM treatments, followed by daily drug gavage until they were killed ten weeks later, colons were examined for aberrant crypt foci (ACF) and prostaglandin E 2 production. All drugs significantly enhanced apoptosis and inhibited ACF, irrespective of their COX-inhibiting potency (p<0.01), but sulindac was more potent in inhibition of large ACF, p<0.05. COX-inhibiting sulindac achieved the greatest protective effect. The greater safety profile of Rac-FB should provide an advantage for chemoprevention.This work was supported by the National Health and Medical Research Council (NHMRC) and Cancer Council of South Australia (CCSA) (project no: 1007501 and 525925)

Eggshell membrane: A possible new natural therapeutic for joint and connective tissue disorders. Results from two open-label human clinical studies

Kevin J Ruff1, Dale P DeVore2, Michael D Leu3, Mark A Robinson41ESM Technologies, LLC, Carthage, MO, USA; 2Membrell, LLC, Carthage, MO, USA; 3Private Practice, Jenks, OK, USA; 4Robinson Family Health Center, Carthage, MO, USABackground: Natural Eggshell Membrane (NEM&reg;) is a novel dietary supplement that contains naturally occurring glycosaminoglycans and proteins essential for maintaining healthy joint and connective tissues. Two single center, open-label human clinical studies were conducted to evaluate the efficacy and safety of NEM&reg; as a treatment for pain and inflexibility associated with joint and connective tissue disorders. Methods: Eleven (single-arm trial) and 28 (double-arm trial) patients received oral NEM&reg; 500 mg once daily for four weeks. The primary outcome measure was to evaluate the change in general pain associated with the treatment joints/areas (both studies). In the single-arm trial, range of motion (ROM) and related ROM-associated pain was also evaluated. The primary treatment response endpoints were at seven and 30 days. Both clinical assessments were performed on the intent-to-treat (ITT) population within each study.Results: Single-arm trial: Supplementation with NEM&reg; produced a significant treatment&nbsp;response at seven days for flexibility (27.8% increase; P = 0.038) and at 30 days for general pain (72.5% reduction; P = 0.007), flexibility (43.7% increase; P = 0.006), and ROM-associated pain (75.9% reduction; P = 0.021). Double-arm trial: Supplementation with NEM&reg; produced a significant treatment response for pain at seven days for both treatment arms (X: 18.4% reduction; P = 0.021. Y: 31.3% reduction; P = 0.014). There was no clinically meaningful difference between treatment arms at seven days, so the Y arm crossed over to the X formulation for the remainder of the study. The significant treatment response continued through 30 days for pain (30.2% reduction; P = 0.0001). There were no adverse events reported during either study and the treatment was reported to be well tolerated by study participants. Conclusions: Natural Eggshell Membrane (NEM&reg;) is a possible new effective and safe therapeutic option for the treatment of pain and inflexibility associated with joint and connective tissue (JCT) disorders. Supplementation with NEM&reg;, 500 mg taken once daily, significantly reduced pain, both rapidly (seven days) and continuously (30 days). It also showed clinically meaningful results from a brief responder analysis, demonstrating that significant proportions of treated patients may be helped considerably from NEM&reg; supplementation. The Clinical Trial Registration numbers for these trials are: NCT00750230 and NCT00750854.Keywords: arthritis, pain, stiffness, eggshell membrane, joint, connective tissue, complimentary, alternativ

Dietary red meat aggravates dextran sulfate sodium-induced colitis in mice whereas resistant starch attenuates inflammation

Although a genetic component has been identified as a risk factor for developing inflammatory bowel disease, there is evidence that dietary factors also play a role in the development of this disease. Aims The aim of this study was to determine the effects of feeding a red meat diet with and without resistant starch (RS) to mice with dextran sulfate sodium (DSS)-induced colitis. Methods Colonic experimental colitis was induced in Balb/c mice using DSS. The severity of colitis was evaluated based on a disease activity index (based on bodyweight loss, stool consistency, rectal bleeding, and overall condition of the animal) and a histological score. Estimations were made of numbers of a range of different bacteria in the treatment pools of cecal digesta using quantitative real-time PCR. Results Consumption of a diet high in red meat increased DSS-induced colitis as evidenced by higher disease activity and histopathological scores. Addition of RS to the red meat diet exerted a beneficial effect in acute DSS-induced colitis. Subjective analysis of numbers of a range of bacterial targets suggest changes in the gut microbiota abundance were induced by red meat and RS treatments and these changes could contribute to the reported outcomes. Conclusions A dietary intake of red meat aggravates DSS-induced colitis whereas co-consumption of resistant starch reduces the severity of colitis.This work was supported by the National Health and Medical Research Council (grant ID 535079) and CSIRO Preventative Health National Research Flagship

Diffusion MR Characteristics Following Concurrent Radiochemotherapy Predicts Progression-Free and Overall Survival in Newly Diagnosed Glioblastoma.

The standard of care for newly diagnosed glioblastoma (GBM) is surgery, then radiotherapy (RT) with concurrent temozolomide (TMZ), followed by adjuvant TMZ. We hypothesized patients with low diffusivity measured using apparent diffusion coefficient (ADC) histogram analysis evaluated after RT+TMZ, prior to adjuvant TMZ, would have a significantly shorter progression-free (PFS) and overall survival (OS). To test this hypothesis we evaluated 120 patients with newly diagnosed GBM receiving RT+TMZ followed by adjuvant TMZ. MRI was performed after completion of RT+TMZ, prior to initiation of adjuvant TMZ. A double Gaussian mixed model was used to describe the ADC histograms within the enhancing tumor, where ADCL and ADCH were defined as the mean ADC value of the lower and higher Gaussian distribution, respectively. An ADCL value of 1.0 um2/ms and ADCH value of 1.6 um2/ms were used to stratify patients into high and low risk categories. Results suggest patients with low ADCL had significantly shorter PFS (Cox Hazard Ratio = 0.12, P = 0.0006). OS was significantly shorter with low ADCL tumors, showing a median OS of 407 vs. 644 days (Cox Hazard Ratio = 0.31, P = 0.047). ADCH was not predictive of PFS or OS when accounting for age and ADCL. In summary, newly diagnosed glioblastoma patients with low ADCL after completion of RT+TMZ are likely to progress and die earlier than patients with higher ADCL. Results suggest ADC histogram analysis may be useful for patient risk stratification following completion of RT+TMZ

Accumulation of promutagenic DNA adducts in the mouse distal colon after consumption of heme does not induce colonic neoplasms in the western diet model of spontaneous colorectal cancer

Author version made available in accordance with Publisher copyright policy.Scope: Red meat is considered a risk factor for colorectal cancer (CRC). Heme is considered to promote colonic hyperproliferation and cell damage. Resistant starch (RS) is a food that ferments in the colon with studies demonstrating protective effects against CRC. By utilizing the western diet model of spontaneous CRC, we determined if feeding heme (as hemin chloride) equivalent to a high red meat diet would increase colonic DNA adducts and CRC and whether RS could abrogate such effects. Methods and results: Four groups of mice: control, heme, RS and heme + RS were fed diets for 1 or 18 months. Colons were analyzed for apoptosis, proliferation, DNA adducts “8-hydroxy-2-deoxyguanosine” and “O6-methyl-2-deoxyguanosine” (O6MeG), and neoplasms. In the short term, heme increased cell proliferation (p < 0.05). Changes from 1 to 18 months showed increased cell proliferation (p<0.01) and 8-hydroxy-2-deoxyguanosine adducts (p < 0.05) in all groups, but only heme-fed mice showed reduced apoptosis (p < 0.01) and increasedO6MeGadducts (p<0.01). The incidence of colon neoplasms was not different between any interventions. Conclusion: We identified heme to increase proliferation in the short term, inhibit apoptosis over the long term, and increase O6MeG adducts in the colon over time although these changes did not affect colonic neoplasms within this mouse model.Funding for this project was provided by the National Health and Medical Research Council of Australia (Project number 535079).We would like to acknowledge the Royal Society of Edinburgh for funding a visit for Dr. SilviaGratz fromUKto Australia to carry out work associated with this project

Combination of selenium and green tea improves the efficacy of chemoprevention in a rat colorectal cancer model by modulating genetic and epigenetic biomarkers

Dietary supplementation of selenium and green tea holds promise in cancer prevention. In this study, we evaluated the efficacies of selenium and green tea administered individually and in combination against colorectal cancer in an azoxymethane (AOM)-induced rat colonic carcinogenesis model and determined the underlying mechanisms of the protection. Four-week old Sprague-Dawley male rats were fed with diets containing 0.5% green tea extract, 1ppm selenium as selenium-enriched milk protein, or combination of 1ppm selenium and 0.5% green tea extract. Animals received 2 AOM (15 mg/kg) treatments to induce colonic oncogenesis. Rats were killed 8 or 30 wk later after the last AOM to examine the effect of dietary intervention on aberrant crypt foci (ACF) formation or tumor development. On sacrifice, colons were examined for ACF and tumors, the mRNA levels of SFRP5 and Cyclin D1, and the proteins levels of ß-catenin, COX-2, Ki-67, DNMT1 and acetyl histone H3. The combination of selenium and green tea resulted in a significant additive inhibition of large ACF formation, this effect was greater than either selenium or green tea alone, P,0.01; the combination also had a significant additive inhibition effect on all tumor endpoints, the effect of the combination diet on tumor incidence, multiplicity and size was greater than selenium or green tea alone, P,0.01. Rats fed the combination diet showed marked reduction of DNMT1 expression and induction of histone H3 acetylation, which were accompanied by restoration of SFRP5 mRNA in normal-appearing colonic crypts. The combination diet also significantly reduced ß-catenin nuclear translocation, Cyclin D1 expression and cell proliferation. These data show, for the first time, that combination of selenium and green tea is more effective in suppressing colorectal oncogenesis than either agent alone. The preventive effect is associated with regulation of genetic and epigenetic biomarkers implicated in colonic carcinogenesis