The coupling between healthspan and lifespan in Caenorhabditis depends on complex interactions between compound intervention and genetic background

Aging is characterized by declining health that results in decreased cellular resilience and neuromuscular function. The relationship between lifespan and health, and the influence of genetic background on that relationship, has important implications in the development of pharmacological anti-aging interventions. Here we assessed swimming performance as well as survival under thermal and oxidative stress across a nematode genetic diversity test panel to evaluate health effects for three compounds previously studied in the Caenorhabditis Intervention Testing Program and thought to promote longevity in different ways - NP1 (nitrophenyl piperazine-containing compound 1), propyl gallate, and resveratrol. Overall, we find the relationships among median lifespan, oxidative stress resistance, thermotolerance, and mobility vigor to be complex. We show that oxidative stress resistance and thermotolerance vary with compound intervention, genetic background, and age. The effects of tested compounds on swimming locomotion, in contrast, are largely species-specific. In this study, thermotolerance, but not oxidative stress or swimming ability, correlates with lifespan. Notably, some compounds exert strong impact on some health measures without an equally strong impact on lifespan. Our results demonstrate the importance of assessing health and lifespan across genetic backgrounds in the effort to identify reproducible anti-aging interventions, with data underscoring how personalized treatments might be required to optimize health benefits.

Antioxidants green tea extract and nordihydroguaiaretic acid confer species and strain-specific lifespan and health effects in Caenorhabditis nematodes

The Caenorhabditis Intervention Testing Program (CITP) is an NIH-funded research consortium of investigators who conduct analyses at three independent sites to identify chemical interventions that reproducibly promote health and lifespan in a robust manner. The founding principle of the CITP is that compounds with positive effects across a genetically diverse panel of Caenorhabditis species and strains are likely engaging conserved biochemical pathways to exert their effects. As such, interventions that are broadly efficacious might be considered prominent compounds for translation for pre-clinical research and human clinical applications. Here, we report results generated using a recently streamlined pipeline approach for the evaluation of the effects of chemical compounds on lifespan and health. We studied five compounds previously shown to extend C. elegans lifespan or thought to promote mammalian health: 17α-estradiol, acarbose, green tea extract, nordihydroguaiaretic acid, and rapamycin. We found that green tea extract and nordihydroguaiaretic acid extend Caenorhabditis lifespan in a species-specific manner. Additionally, these two antioxidants conferred assay-specific effects in some studies-for example, decreasing survival for certain genetic backgrounds in manual survival assays in contrast with extended lifespan as assayed using automated C. elegans Lifespan Machines. We also observed that GTE and NDGA impact on older adult mobility capacity is dependent on genetic background, and that GTE reduces oxidative stress resistance in some Caenorhabditis strains. Overall, our analysis of the five compounds supports the general idea that genetic background and assay type can influence lifespan and health effects of compounds, and underscores that lifespan and health can be uncoupled by chemical interventions.

Metformin treatment of diverse Caenorhabditis species reveals the importance of genetic background in longevity and healthspan extension outcomes

Metformin, the most commonly prescribed anti‐diabetes medication, has multiple reported health benefits, including lowering the risks of cardiovascular disease and cancer, improving cognitive function with age, extending survival in diabetic patients, and, in several animal models, promoting youthful physiology and lifespan. Due to its longevity and health effects, metformin is now the focus of the first proposed clinical trial of an anti‐aging drug—the Targeting Aging with Metformin (TAME) program. Genetic variation will likely influence outcomes when studying metformin health effects in human populations. To test for metformin impact in diverse genetic backgrounds, we measured lifespan and healthspan effects of metformin treatment in three Caenorhabditis species representing genetic variability greater than that between mice and humans. We show that metformin increases median survival in three C. elegans strains, but not in C. briggsae and C. tropicalis strains. In C. briggsae, metformin either has no impact on survival or decreases lifespan. In C. tropicalis, metformin decreases median survival in a dose‐dependent manner. We show that metformin prolongs the period of youthful vigor in all C. elegans strains and in two C. briggsae strains, but that metformin has a negative impact on the locomotion of C. tropicalis strains. Our data demonstrate that metformin can be a robust promoter of healthy aging across different genetic backgrounds, but that genetic variation can determine whether metformin has positive, neutral, or negative lifespan/healthspan impact. These results underscore the importance of tailoring treatment to individuals when testing for metformin health benefits in diverse human populations.

The use of high-dose dual-impregnated antibiotic-laden cement with hemiarthroplasty for the treatment of a fracture of the hip: The Fractured Hip Infection trial

Aims

A fracture of the hip is the most common serious orthopaedic injury, and surgical site infection (SSI) is one of the most significant complications, resulting in increased mortality, prolonged hospital stay and often the need for further surgery. Our aim was to determine whether high dose dual antibiotic impregnated bone cement decreases the rate of infection.

Patients and Methods

A quasi-randomised study of 848 patients with an intracapsular fracture of the hip was conducted in one large teaching hospital on two sites. All were treated with a hemiarthroplasty. A total of 448 patients received low dose single-antibiotic impregnated cement (control group) and 400 patients received high dose dual-antibiotic impregnated cement (intervention group). The primary outcome measure was deep SSI at one year after surgery.

Results

The rate of deep SSI was 3.5% in the control group and 1.1% in the intervention group (p = 0.041; logistic regression adjusting for age and gender). The overall rate of non-infective surgical complications did not differ between the two groups (unadjusted chi-squared test; p > 0.999).

Conclusion

The use of high dose dual-antibiotic impregnated cement in these patients significantly reduces the rate of SSI compared with standard low dose single antibiotic loaded bone cement.

Cite this article: Bone Joint J 2016;98-B:1534–1541.

Abstract P1-06-02: Inflammatory stromal cell response induced by collagen dense stroma is regulated by cyclooxygenase-2 in a mouse breast cancer model

Breast cancer is the most common invasive cancer in women, causing 40,000 deaths yearly in the United States. Increased mammographic density correlates with over four-fold increase risk for breast cancer, making it one of the greatest risk factors known for this disease. High breast density is mainly attributable to elevated collagen matrix deposition in the breast tissue, and we have found that increased collagen in the Col1a1tm1jae mouse model promotes mammary tumor formation and progression. Increased collagen density in vitro increases expression of PTGS2 (prostaglandin-endoperoxide synthase 2), the gene for cyclooxygenase-2 (COX-2), by over four fold. COX-2 over-expression is observed in 40% of invasive breast carcinoma cases and correlates with poor prognosis. Based on these findings, we hypothesized that inhibition of COX-2 may be an effective therapeutic in the context of mammary tumors arising in dense tissue. Celecoxib is a selective non-steroidal anti-inflammatory drug (NSAID) that specifically inhibits COX-2. To understand how COX-2 affects response to collagen matrix density, we utilized our previously characterized mouse model of MMTV-PyVT tumors in a wild type (wt) or Col1a1tm1jae background (HD, High Density). Col1a1tm1jae heterozygote or wt littermates were randomly assigned at 11 weeks of age to treatment with vehicle or celecoxib at 0.2mg per mouse per day. Oral treatment was given daily for 21 days. We found that MMTV-PyVT tumors responded to celecoxib in a manner that is regulated by matrix density. Tumors that arose on the dense Col1a1tm1jae background (HD) were larger and more invasive (p < .0001) and expressed higher levels of COX-2 and PGE2 than their wt littermates. Both COX-2 (wt: p = 0.0025, HD: p < 0.0001) and PGE2 (wt: p = 0.0196, HD: p = 0.0002) levels were decreased in animals treated with celecoxib. However, Ki-67 and syndecan 1 levels decreased only in HD mice that received treatment with celecoxib (p = 0.0003, p = 0.0007, respectively). In addition, total number of macrophages (wt: p = 0.0052, HD: p < 0.0001) and fibroblasts (wt: p = 0.0133, HD: p = 0.0003) were diminished in animals treated with celecoxib independently of collagen density. On the other hand, cancer associated fibroblast (CAF) population was diminished only in HD mice treated with celecoxib (p = 0.0002) which, along with the synedan-1 result suggests that celecoxib selectively abrogates the inflammatory response from reactive stroma only. Consequently, we find that celecoxib treatment remodels collagen fiber organization, such that it more closely resembles wt assembly. Ongoing studies will identify different macrophage populations, and which stromal cell populations express COX-2 and PGE2. These findings suggest that COX-2 has a direct role in modulating tumor progression in dense matrices which promote invasion. Moreover, these findings suggest that COX-2 may be an effective therapeutic target for women with dense breast tissue.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-06-02.

Microcomputer education for nursing: an approach to microcomputer education in a large tertiary care center

Communication skills needed for the healthcare environment are changing. In the past, poor reading and writing skills made it difficult to use a paper chart. Current computer technology provides many new opportunities for communicating in the clinical setting. Computer literacy has become a necessary skill for efficient use of clinical computer systems. At this large tertiary care setting, a survey was developed and distributed to staff to assess learner needs. Nursing staff identified educational needs for basic computer knowledge, the ability to move between computer functions, and the skills to navigate through specific applications. Based on survey analysis, three educational classes were constructed that addressed the department's specific needs.

Genetic approaches to neurotrauma research: opportunities and potential pitfalls of murine models

Genetic strategies provide new ways to define the molecular cascades that regulate the responses of the mammalian nervous system to injury. Genetic interventions also provide opportunities to manipulate and control key molecular steps in these cascades, so as to modify the outcome of CNS injury. Most current genetic strategies involve the use of mice, an animal that has not heretofore been used extensively for neurotrauma research. Therefore, one purpose of the present review is to consider how mice respond to neural trauma, focusing especially on recent information that reveals important differences between mice and rats, and between different inbred strains of mice. The second aim of this review is to provide a brief introduction to the opportunities, caveats, and potential pitfalls of studies that use genetically modified animals for neurotrauma research.

Consolidation and its consequences

A small market place dominated by large companies is becoming the new business environment for the industry. But this will not result in stasis. Large companies will continually analyse and restructure their portfolios and niche companies will emerge and be acquired. This article explores current industry dynamics and their effects.

Effects of all-trans retinoic acid and Ca++ on human skin in organ culture

In this study, we have established an organ culture model of human skin and examined the effects of both all-trans retinoic acid (RA) and extracellular Ca++ on the epidermal and dermal components of the organ-cultured skin. Our data show that while organ cultures maintained in serum-free, growth factor-free culture medium containing 0.15 mM Ca++ degenerated rapidly, those treated with concentrations of RA that have been shown previously to stimulate fibroblast and keratinocyte proliferation in monolayer culture (J Invest Dermatol 1989, 93:449; 1990, 94:717; Am J Pathol 1990, 136:1275) demonstrated a healthy appearance for up to 12 days. Degeneration of the control cultures was characterized by separation of the epidermis from the underlying dermis, progressive cell necrosis leading to a complete absence of viable cells from both the dermal and epidermal compartments, disintegration and fibrillation of the dermal connective tissue, and a cessation of protein synthesis. RA-treated organ cultures contained large numbers of healthy-appearing cells in both the epidermal and dermal compartments. One or several layers of viable basal cells in the epidermis could be seen at least through day 12. However, the upper layers of the epidermis frequently separated from the cells in the basal layer. The dermal connective tissue was histologically well-preserved. Furthermore, the level of protein synthesis was higher in the RA-treated cultures than in the control cultures. In addition to treating organ cultures with RA, other cultures were exposed to serum-free, growth factor-free culture medium containing 1.4 mM Ca++. The presence of the elevated Ca++ concentration also preserved cellular and connective tissue structures in the dermal and epidermal compartments. In comparison to RA there was better preservation of the overall epidermal structure. The upper layers of epidermal cells did not separate from the basal cells, and the various stages of epithelial differentiation could be seen. Histologically, the dermis was well-preserved in the presence of elevated extracellular Ca++. Specimens treated with a combination of Ca++ and RA demonstrated features consistent with the features induced by each treatment separately. This included an expanded basal layer of epithelial cells and a prominent keratotic layer with a fairly orderly pattern of differentiation. The tendency of the upper epidermis to separate from the basal cells was partially mitigated. Taken together, these data indicate that both RA and extracellular Ca++ act to prevent the degeneration of human skin in organ culture but probably do so through different mechanisms.

Operant conditioning of EMG activity using cigarette puffs as a reinforcer

This study was a test of an operant conditioning model of cravings. The model posits that smoking or opportunity to smoke may reinforce physiological reactions to cigarette deprivation that are typically labeled as cravings. More specifically, the rate and amplitude of a physiological response (EMG activity) can be modified, and brought under stimulus control, using cigarette puffs as a reinforcer. Three adult smokers, who were deceived as to the purpose of the study, served as subjects. Three subjects were exposed to two conditions: baseline and response-contingent tone and puff. A single subject reversal design was used. Two of the three subjects showed conditioning effects with the mean level of EMG responding and rate of criterion responding in the response-contingent condition exceeding baseline levels of responding. For one of these subjects, two additional control conditions were used. Responding in the response-contingent condition was higher than in either control condition. The need for replication and extension of the present procedures are discussed.

THE REVERSIBLE ELECTRODE POTENTIAL OF THE SYSTEM U/UCl3 IN MOLTEN CHLORIDE SOLVENTS

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