22 research outputs found
Rationale and Methods for a Multicenter Clinical Trial Assessing Exercise and Intensive Vascular Risk Reduction in Preventing Dementia (rrAD Study)
Alzheimer\u27s Disease (AD) is an age-related disease with modifiable risk factors such as hypertension, hypercholesterolemia, obesity, and physical inactivity influencing the onset and progression. There is however, no direct evidence that reducing these risk factors prevents or slows AD. The Risk Reduction for Alzheimer\u27s Disease (rrAD) trial is designed to study the independent and combined effects of intensive pharmacological control of blood pressure and cholesterol and exercise training on neurocognitive function. Six hundred and forty cognitively normal older adults age 60 to 85 years with hypertension and increased risk for dementia will be enrolled. Participants are randomized into one of four intervention group for two years: usual care, Intensive Reduction of Vascular Risk factors (IRVR) with blood pressure and cholesterol reduction, exercise training (EX), and IRVR+EX. Neurocognitive function is measured at baseline, 6, 12, 18, and 24 months; brain MRIs are obtained at baseline and 24 months. We hypothesize that both IRVR and EX will improve global cognitive function, while IRVR+EX will provide a greater benefit than either IRVR or EX alone. We also hypothesize that IRVR and EX will slow brain atrophy, improve brain structural and functional connectivity, and improve brain perfusion. Finally, we will explore the mechanisms by which study interventions impact neurocognition and brain. If rrAD interventions are shown to be safe, practical, and successful, our study will have a significant impact on reducing the risks of AD in older adults.
NCT Registration: NCT02913664
Similar Genetic Basis of Resistance to Bt Toxin Cry1Ac in Boll-Selected and Diet-Selected Strains of Pink Bollworm
Genetically engineered cotton and corn plants producing insecticidal Bacillus thuringiensis (Bt) toxins kill some key insect pests. Yet, evolution of resistance by pests threatens long-term insect control by these transgenic Bt crops. We compared the genetic basis of resistance to Bt toxin Cry1Ac in two independently derived, laboratory-selected strains of a major cotton pest, the pink bollworm (Pectinophora gossypiella [Saunders]). The Arizona pooled resistant strain (AZP-R) was started with pink bollworm from 10 field populations and selected with Cry1Ac in diet. The Bt4R resistant strain was started with a long-term susceptible laboratory strain and selected first with Bt cotton bolls and later with Cry1Ac in diet. Previous work showed that AZP-R had three recessive mutations (r1, r2, and r3) in the pink bollworm cadherin gene (PgCad1) linked with resistance to Cry1Ac and Bt cotton producing Cry1Ac. Here we report that inheritance of resistance to a diagnostic concentration of Cry1Ac was recessive in Bt4R. In interstrain complementation tests for allelism, F1 progeny from crosses between AZP-R and Bt4R were resistant to Cry1Ac, indicating a shared resistance locus in the two strains. Molecular analysis of the Bt4R cadherin gene identified a novel 15-bp deletion (r4) predicted to cause the loss of five amino acids upstream of the Cry1Ac-binding region of the cadherin protein. Four recessive mutations in PgCad1 are now implicated in resistance in five different strains, showing that mutations in cadherin are the primary mechanism of resistance to Cry1Ac in laboratory-selected strains of pink bollworm from Arizona
Recommended from our members
Surgical resection of a virilizing adrenal mass with extensive tumor thrombus
Adrenocortical carcinoma with tumor thrombus and concomitant testosterone production is a rare entity. We describe a case of a 53-year-old woman with a testosterone producing left-sided adrenocortical carcinoma with tumor extending to the right atrium and tumor embolus to the right pulmonary artery. To our knowledge, there exist no such reported cases in the medical literature. We describe our use of techniques derived from transplant surgery for the removal of this mass. Critical components for successful resection included early renal artery ligation, hepatic mobilization off the inferior vena cava, and minimization of cardiopulmonary bypass time thus eliminating the need for deep hypothermic circulatory arrest
Anxiety-inducing Facebook behavior is associated with higher rates of upper respiratory infection in college-aged users
Exposure to chronic stress can suppress immune function and increase susceptibility to infection. Recent evidence indicates that social network use (e.g., Facebook) can serve as a chronic stressor to some users and contribute to poor health, however, mechanisms underlying these interactions remain unclear. In the current study we investigated if Facebook user behavior might help start to explain interactions between Facebook use, stress and health. In this prospective study, healthy college students completed online questionnaires assessing Facebook use, health and then were followed for 10 weeks to track incidence of upper respiratory infection (URI). Subjects who reported that Facebook provoked anxiety/stress demonstrated a significantly higher number of URI than those not reporting Facebook-induced anxiety/stress and having more Facebook friends was associated with increased anxiety/stress and the number of URI. Users who demonstrated anxiety regarding their Facebook use were more likely to demonstrate a pattern of increased number of log-ins to Facebook/day and these anxiety-linked behavior patterns were associated with poorer health. The other health practices and psychological processes assessed (e.g., physical activity levels, sleep, social support) do not appear to explain these associations. These results suggest an association between specific Facebook use, psychological anxiety and health might exist
MOLECULAR CHARACTERIZATION OF KIDNEY CANCER: ASSOCIATION OF HYALURONIC ACID FAMILY WITH HISTOLOGICAL SUBTYPES AND METASTASIS
BACKGROUND: Molecular profiling of renal cell carcinomas (RCC) may improve the distinction between oncocytoma and malignant RCC subtypes and aid in early detection of metastasis. Hyaluronic acid (HA) family includes HA-synthases (HAS1, HAS2, HAS3), hyaluronidases (HYAL-1, HYAL-2, HYAL-3, HYAL-4, PH20, HYAL-P1), and HA receptors (CD44s, CD44v and RHAMM). HA family members promote tumor growth and metastasis. We evaluated the expression of HA family members in kidney specimens. METHODS: Using quantitative PCR, mRNA levels of twelve HA family members were measured in tumor specimens obtained from 86 consecutive patients undergoing nephrectomy; 80 of them also provided normal specimens. Mean and median follow-up: 15.2 ± 8.8 and 13.8 months. RCC specimens included: clear cell RCC (ccRCC): 65; papillary: 10; chromophobe: 5; oncocytoma: 6; metastasis (+): 17. RESULTS: Median HAS1, CD44s and RHAMM transcript levels were 3–25 elevated in ccRCC, papillary and chromophobe tumors when compared to normal tissues. HYAL-4, CD44s and RHAMM levels were 4–12-fold elevated in ccRCC and papillary tumors when compared to oncocytomas; only HYAL-4 levels distinguished between chromophobe and oncocytoma (P=0.009). CD44s and RHAMM levels were significantly higher in tumors < 4-cm (510±611; 19.6±20.8, respectively) when compared to oncocytoma (46.4±20; 3.8±2.5; P≤0.006). In univariate and multivariate analyses, CD44s (P<0.0001), RHAMM (P<0.0001), stage, tumor size, and/or renal vein involvement significantly associated with metastasis. The combined CD44s+RHAMM marker had 82% sensitivity and 86% specificity to predict metastasis. CONCLUSION: CD44s and RHAMM levels distinguish between oncocytoma and RCC subtypes regardless of tumor size and are potential predictors of RCC metastasis