DEN+2-AAF-induced multistep hepatotumorigenesis in Wistar rats: supportive evidence and insights

Diethylnitrosamine (DEN), found in many commonly consumed foods, has been reported to induce cancers in animals and humans. Several models have been developed to study multistage carcinogenesis in rat liver; these include the Solt–Farber-resistant hepatocyte model. In the Solt–Farber model, the initiation consists of either a necrogenic dose of a hepatocarcinogen or a non-necrogenic dose in conjunction with partial hepatectomy (PH). We report a novel protocol for tumor induction in liver which eliminates the need for PH. Male Wistar rats were injected with single i.p. dose of DEN (200 mg/kg body weight), controls received saline only. After 1 week of recovery, the DEN-treated animals were administered with the repeated doses of 2-acetyamino fluorine (150 mg/kg body weight) orally in 1 % carboxymethyl cellulose that served as promoting agent. Thirty days after the DEN administration, hepatocellular damage was observed as evident by histopathological analysis. The marker enzyme analysis showed elevated levels of serum AST, ALT, and alkaline phosphatase and a decrease in the levels of liver superoxide dismutase and catalase. The oxidative stress in liver was confirmed by elevated levels of lipid peroxidation and a decrease in antioxidant parameters.     

High Level Activity of Recombinant Lysostaphin After Computer Simulation and Additive-Based Refolding

International Journal of Peptide Research and Therapeutics - Lysostaphin is a peptidoglycan hydrolase, produced by Staphylococcus simulans, which has illustrated significant bactericidal activities...     

Outcomes of deliveries by family physicians or obstetricians: a population-based cohort study using an instrumental variable

Background:

Previous research has suggested that obstetric outcomes are similar for deliveries by family physicians and obstetricians, but many of these studies were small, and none of them adjusted for unmeasured selection bias. We compared obstetric outcomes between these provider types using an econometric method designed to adjust for unobserved confounding.

Methods:

We performed a retrospective population-based cohort study of all Canadian (except Quebec) hospital births with delivery by family physicians and obstetricians at more than 20 weeks gestational age, with birth weight greater than 500 g, between Apr. 1, 2006, and Mar. 31, 2009. The primary outcomes were the relative risks of in-hospital perinatal death and a composite of maternal mortality and major morbidity assessed with multivariable logistic regression and instrumental variable–adjusted multivariable regression.

Results:

After exclusions, there were 3600 perinatal deaths and 14 394 cases of maternal morbidity among 799 823 infants and 793 053 mothers at 390 hospitals. For deliveries by family physicians v. obstetricians, the relative risk of perinatal mortality was 0.98 (95% confidence interval [CI] 0.85–1.14) and of maternal morbidity was 0.81 (95% CI 0.70–0.94) according to logistic regression. The respective relative risks were 0.97 (95% CI 0.58–1.64) and 1.13 (95% CI 0.65–1.95) according to instrumental variable methods.

Interpretation:

After adjusting for both observed and unobserved confounders, we found a similar risk of perinatal mortality and adverse maternal outcome for obstetric deliveries by family physicians and obstetricians. Whether there are differences between these groups for other outcomes remains to be seen.Over the past several decades in Canada, obstetric deliveries have increasingly been attended by specialist obstetricians rather than family physicians.¹ Although specialized care is beneficial for high-risk mothers and their infants,^2–4 there are concerns that it might increase risk for women whose deliveries could be safely managed without a specialized approach. Most prior studies have concluded that obstetric outcomes between family physicians and obstetricians are similar, but many of these studies were small, and none of them adjusted for unmeasured factors that might affect both the choice of delivery provider and outcomes.^5–8Obstetric risk is typically divided between providers, with family physicians and obstetricians sharing the lowest-risk patients, obstetricians caring for moderate-risk patients, and sub-specialized perinatologists caring for the highest-risk individuals. Although traditional statistical methods can be used to adjust for observed differences between these groups, they cannot be used to adjust for unobserved differences. For example, the presence of gestational diabetes mellitus is usually noted, but its severity is often not coded in administrative databases. Women with mild diabetes mellitus are usually eligible for delivery by family physicians, but those with severe diabetes (and the attendant increased risk of adverse outcome) are not. There are many prominent examples where traditional analyses of observational data produced results that were subsequently refuted by randomized trials, presumably because of these unmeasured or unknown factors that also affect treatment decisions or outcomes.^4,9–11The instrumental variable method from the field of econometrics is a technique designed to control for unmeasured covariates in regression analyses. Results from instrumental variable–controlled observational analyses of the effect of angiography after myocardial infarction⁹ and of long-acting bronchodilators on asthma control¹² closely approximated those of randomized controlled trials, whereas analyses using traditional statistical methods differed substantially. Instrumental variable analyses of obstetric data have shown that traditional statistical approaches significantly underestimate the mortality benefit of high-volume hospitals for high-risk neonates.⁴ The objective of the current study was to compare perinatal mortality and maternal morbidity and mortality for deliveries by family physicians and obstetricians using instrumental variable methodology.     

Analysis of serum heat shock protein 70 (HSPA1A) concentrations for diagnosis and disease activity monitoring in patients with rheumatoid arthritis

Heat shock proteins (HSPs) have been repeatedly implicated in the pathogenesis of rheumatoid arthritis (RA). The authors aimed to study applicability of heat shock protein 70 (HSPA1A) serum levels as a diagnostic factor and a severity indicator in patients with RA and to quantify cut-off point that predicts status of RA with highest specificity. A total of 76 patients with RA and 36 healthy adults were studied in this case-control analysis. Patients had a higher HSPA1A level than the control group (0.78 ± 0.13 vs. 0.12 ± 0.02 ng/mL, p = 0.006), irrespective of presence of absence of rheumatoid factor or anti-citrullinated cyclic peptide. Next, diagnostic accuracy of the HSPA1A in diagnosis of RA was evaluated (area under curve 0.71; p < 0.05). HSPA1A predicted status of having RA in levels above 0.42 ng/mL with more than 90 % specificity. In addition to diagnostic value, HSPA1A can distinguish between high disease activity (1.66 ± 0.75 ng/mL) and low (0.49 ± 0.1 ng/mL), moderate (0.52 ± 0.12 ng/mL), or remission phase (0.48 ± 0.11 ng/mL). Moreover, patients in remission still had a higher HSPA1A level compared to normal subject (0.48 ± 0.11 vs. 0.12 ± 0.02 ng/mL, p < 0.05). Our results showed that serum HSPA1A could be implemented as a specific tool to facilitate diagnosis and monitoring disease activity in patients with rheumatoid arthritis.

Electronic supplementary material

The online version of this article (doi:10.1007/s12192-015-0578-z) contains supplementary material, which is available to authorized users.     

Measuring biological aging in humans: A quest

The global population of individuals over the age of 65 is growing at an unprecedented rate and is expected to reach 1.6 billion by 2050. Most older individuals are affected by multiple chronic diseases, leading to complex drug treatments and increased risk of physical and cognitive disability. Improving or preserving the health and quality of life of these individuals is challenging due to a lack of well‐established clinical guidelines. Physicians are often forced to engage in cycles of “trial and error” that are centered on palliative treatment of symptoms rather than the root cause, often resulting in dubious outcomes. Recently, geroscience challenged this view, proposing that the underlying biological mechanisms of aging are central to the global increase in susceptibility to disease and disability that occurs with aging. In fact, strong correlations have recently been revealed between health dimensions and phenotypes that are typical of aging, especially with autophagy, mitochondrial function, cellular senescence, and DNA methylation. Current research focuses on measuring the pace of aging to identify individuals who are “aging faster” to test and develop interventions that could prevent or delay the progression of multimorbidity and disability with aging. Understanding how the underlying biological mechanisms of aging connect to and impact longitudinal changes in health trajectories offers a unique opportunity to identify resilience mechanisms, their dynamic changes, and their impact on stress responses. Harnessing how to evoke and control resilience mechanisms in individuals with successful aging could lead to writing a new chapter in human medicine.     

Induction of tenogenic differentiation of equine adipose-derived mesenchymal stem cells by platelet-derived growth factor-BB and growth differentiation factor-6

Molecular Biology Reports - Managing&nbsp;tendon healing process is complicated mainly due to&nbsp;the limited regeneration capacity of tendon tissue. Mesenchymal stem cells (MSCs) have...     

Editor's Choice: Mate Pair Sequencing of Whole-Genome-Amplified DNA Following Laser Capture Microdissection of Prostate Cancer

High-throughput next-generation sequencing provides a revolutionary platform to unravel the precise DNA aberrations concealed within subgroups of tumour cells. However, in many instances, the limited number of cells makes the application of this technology in tumour heterogeneity studies a challenge. In order to address these limitations, we present a novel methodology to partner laser capture microdissection (LCM) with sequencing platforms, through a whole-genome amplification (WGA) protocol performed in situ directly on LCM engrafted cells. We further adapted current Illumina mate pair (MP) sequencing protocols to the input of WGA DNA and used this technology to investigate large genomic rearrangements in adjacent Gleason Pattern 3 and 4 prostate tumours separately collected by LCM. Sequencing data predicted genome coverage and depths similar to unamplified genomic DNA, with limited repetition and bias predicted in WGA protocols. Mapping algorithms developed in our laboratory predicted high-confidence rearrangements and selected events each demonstrated the predicted fusion junctions upon validation. Rearrangements were additionally confirmed in unamplified tissue and evaluated in adjacent benign-appearing tissues. A detailed understanding of gene fusions that characterize cancer will be critical in the development of biomarkers to predict the clinical outcome. The described methodology provides a mechanism of efficiently defining these events in limited pure populations of tumour tissue, aiding in the derivation of genomic aberrations that initiate cancer and drive cancer progression.     

Host differences in influenza-specific CD4 T cell and B cell responses are modulated by viral strain and route of immunization

The antibody response to influenza infection is largely dependent on CD4 T cell help for B cells. Cognate signals and secreted factors provided by CD4 T cells drive B cell activation and regulate antibody isotype switching for optimal antiviral activity. Recently, we analyzed HLA-DR1 transgenic (DR1) mice and C57BL/10 (B10) mice after infection with influenza virus A/New Caledonia/20/99 (NC) and defined epitopes recognized by virus-specific CD4 T cells. Using this information in the current study, we demonstrate that the pattern of secretion of IL-2, IFN-γ, and IL-4 by CD4 T cells activated by NC infection is largely independent of epitope specificity and the magnitude of the epitope-specific response. Interestingly, however, the characteristics of the virus-specific CD4 T cell and the B cell response to NC infection differed in DR1 and B10 mice. The response in B10 mice featured predominantly IFN-γ-secreting CD4 T cells and strong IgG2b/IgG2c production. In contrast, in DR1 mice most CD4 T cells secreted IL-2 and IgG production was IgG1-biased. Infection of DR1 mice with influenza PR8 generated a response that was comparable to that in B10 mice, with predominantly IFN-γ-secreting CD4 T cells and greater numbers of IgG2c than IgG1 antibody-secreting cells. The response to intramuscular vaccination with inactivated NC was similar in DR1 and B10 mice; the majority of CD4 T cells secreted IL-2 and most IgG antibody-secreting cells produced IgG2b or IgG2c. Our findings identify inherent host influences on characteristics of the virus-specific CD4 T cell and B cell responses that are restricted to the lung environment. Furthermore, we show that these host influences are substantially modulated by the type of infecting virus via the early induction of innate factors. Our findings emphasize the importance of immunization strategy for demonstrating inherent host differences in CD4 T cell and B cell responses.     

S. choloroleuca, S. mirzayanii and S. santolinifolia protect PC12 cells from H(2)O (2)-induced apoptosis by blocking the intrinsic pathway

Several studies have shown that neuronal cell death due to apoptosis is the major reason for cognitive decline in Alzheimer's disease. In this study, we report the anti-apoptotic effects of three Salvia species from Iran-S. choloroleuca, S. mirzayanii and S. santolinifolia-against H(2)O(2)-induced cytotoxicity in neuron-like PC12 cells. We showed that these antioxidant species could interfere with the intrinsic pathway of apoptosis by attenuating Bax/Bcl-2 ratio, decreasing outer mitochondrial membrane break and decreasing cytochrome c release to cytoplasm. Interestingly, we found that these species were able to replenish reduced glutathione level which affects cellular redox status and cytochrome c activity. Moreover, the decreased level of caspase-3, the executioner caspase, resulted in decrease of PARP-1 cleavage. Anti-apoptotic effects of these species along with their antioxidant effects, may represent a promising approach for treatment of neurodegenerative diseases.