263 research outputs found
The impact of seawater saturation state and bicarbonate ion concentration on calcification by new recruits of two Atlantic corals
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Coral Reefs 30 (2011): 321-328, doi:10.1007/s00338-010-0697-z.Rising concentrations of atmospheric CO2 are changing the carbonate chemistry of the
oceans, a process known as ocean acidification (OA). Absorption of this CO2 by the surface oceans
is increasing the amount of total dissolved inorganic carbon (DIC) and bicarbonate ion (HCO3
-)
available for marine calcification, yet is simultaneously lowering the seawater pH and carbonate
ion concentration ([CO3
2-]), and thus the saturation state of seawater with respect to aragonite
(Ωar). We investigated the relative importance of [HCO3
-] versus [CO3
2-] for early calcification by
new recruits (primary polyps settled from zooxanthellate larvae) of two tropical coral species,
Favia fragum and Porites astreoides. The polyps were reared over a range of Ωar values, which
were manipulated by both acid-addition at constant pCO2 (decreased total [HCO3
-] and [CO3
2-])
and by pCO2 elevation at constant alkalinity (increased [HCO3
-], decreased [CO3
2-]). Calcification
after two weeks was quantified by weighing the complete skeleton (corallite) accreted by each
polyp over the course of the experiment. Both species exhibited the same negative response to
decreasing [CO3
2-] whether Ωar was lowered by acid-addition or by pCO2 elevation - calcification
did not follow total DIC or [HCO3
-]. Nevertheless, the calcification response to decreasing [CO3
2-]
was non-linear. A statistically significant decrease in calcification was only detected between Ωar =
< 2.5 and Ωar = 1.1 – 1.5, where calcification of new recruits was reduced by 22 – 37 % per 1.0
decrease in Ωar. Our results differ from many previous studies that report a linear coral
calcification response to OA, and from those showing that calcification increases with increasing
[HCO3
-]. Clearly, the coral calcification response to OA is variable and complex. A deeper
understanding of the biomineralization mechanisms and environmental conditions underlying these
3
variable responses is needed to support informed predictions about future OA impacts on corals
and coral reefs.This study was supported by NSF award 0648157 (Cohen and McCorkle), NSF 1041106 (Cohen,
McCorkle), NSF 1041052 (de Putron), the VITA foundation (de Putron), WHOI Ocean Life
Institute (Cohen), PEI and EEB Departments at Princeton University, Bill and Anne Charrier, and
the Anthony B. Evnin, Dean’s Roundtable, and Edmund Hayes Sr. senior thesis funds (Dillon)
Modulation of the immune response by nematode secreted acetylcholinesterase revealed by heterologous expression in Trypanosoma musculi
Nematode parasites secrete molecules which regulate the mammalian immune system, but their genetic intractability is a major impediment to identifying and characterising the biological effects of these molecules. We describe here a novel system for heterologous expression of helminth secreted proteins in the natural parasite of mice, Trypanosoma musculi, which can be used to analyse putative immunomodulatory functions. Trypanosomes were engineered to express a secreted acetylcholinesterase from Nippostrongylus brasiliensis. Infection of mice with transgenic parasites expressing acetylcholinesterase resulted in truncated infection, with trypanosomes cleared early from the circulation. Analysis of cellular phenotypes indicated that exposure to acetylcholinesterase in vivo promoted classical activation of macrophages (M1), with elevated production of nitric oxide and lowered arginase activity. This most likely occurred due to the altered cytokine environment, as splenocytes from mice infected with T. musculi expressing acetylcholinesterase showed enhanced production of IFNγ and TNFα, with diminished IL-4, IL-13 and IL-5. These results suggest that one of the functions of nematode secreted acetylcholinesterase may be to alter the cytokine environment in order to inhibit development of M2 macrophages which are deleterious to parasite survival. Transgenic T. musculi represents a valuable new vehicle to screen for novel immunoregulatory proteins by extracellular delivery in vivo to the murine host
Incidence of synchronous appendiceal neoplasm in patients with colorectal cancer and its clinical significance
<p>Abstract</p> <p>Background</p> <p>The aims of this study were to evaluate the incidence of synchronous appendiceal neoplasm in patients with colorectal cancer, and to determine its clinical significance.</p> <p>Methods</p> <p>Pathological reports and medical records were reviewed of patients with colorectal adenocarcinoma who underwent oncological resection of the tumor together with appendectomy at the Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand between September 2000 and April 2008.</p> <p>Results</p> <p>This study included 293 patients with an average age of 62 years (range 19–95) and 51 percent were male. Of the patients studied, 228 (78 percent) had right hemicolectomy, whereas the others (22 percent) had surgery for left-sided colon cancer or rectal cancer. One patient (0.3 percent) had epithelial appendiceal neoplasm (mucinous cystadenoma) and 3 patients (1.0 percent) had metastatic colorectal cancer in the mesoappendix. However, the presence of synchronous appendiceal tumors and/or metastasis did not alter postoperative management, as these patients had received adjuvant therapy and were scheduled for surveillance program because of nodal involvement.</p> <p>Conclusion</p> <p>The incidence of synchronous primary appendiceal neoplasm and secondary (metastatic) appendiceal neoplasm in colorectal cancer patients was 0.3 and 1.0 percent, respectively. However, these findings did not change the postoperative clinical management.</p
Coral-Bacterial Communities before and after a Coral Mass Spawning Event on Ningaloo Reef
Bacteria associated with three coral species, Acropora tenuis, Pocillopora damicornis and Tubastrea faulkneri, were assessed before and after coral mass spawning on Ningaloo Reef in Western Australia. Two colonies of each species were sampled before and after the mass spawning event and two additional samples were collected for P. damicornis after planulation. A variable 470 bp region of the 16 S rRNA gene was selected for pyrosequencing to provide an understanding of potential variations in coral-associated bacterial diversity and community structure. Bacterial diversity increased for all coral species after spawning as assessed by Chao1 diversity indicators. Minimal changes in community structure were observed at the class level and data at the taxonomical level of genus incorporated into a PCA analysis indicated that despite bacterial diversity increasing after spawning, coral-associated community structure did not shift greatly with samples grouped according to species. However, interesting changes could be detected from the dataset; for example, α-Proteobacteria increased in relative abundance after coral spawning and particularly the Roseobacter clade was found to be prominent in all coral species, indicating that this group may be important in coral reproduction
Is there a demand for physical activity interventions provided by the health care sector? Findings from a population survey
<p>Abstract</p> <p>Background</p> <p>Health care providers in many countries have delivered interventions to improve physical activity levels among their patients. Thus far, less is known about the population's interest to increase their physical activity levels and their opinion about the health care provider's role in physical activity promotion. The aims of this paper were to investigate the self-reported physical activity levels of the population and intention to increase physical activity levels, self-perceived need for support, and opinions about the responsibilities of both individuals and health care providers to promote physical activity.</p> <p>Methods</p> <p>A regional public health survey was mailed to 13 440 adults (aged 18-84 years) living in Östergötland County (Sweden) in 2006. The survey was part of the regular effort by the regional Health Authorities.</p> <p>Results</p> <p>About 25% of the population was categorised as physically active, 38% as moderately active, 27% as somewhat active, and 11% as low active. More than one-third (37%) had no intentions to increase their physical activity levels, 36% had thought about change, while 27% were determined to change. Lower intention to change was mainly associated with increased age and lower education levels. 28% answered that physical activity was the most important health-related behaviour to change "right now" and 15% of those answered that they wanted or needed support to make this change. Of respondents who might be assumed to be in greatest need of increased activity (i.e. respondents reporting poor general health, BMI>30, and inactivity) more than one-quarter wanted support to make improvements to their health. About half of the respondents who wanted support to increase their physical activity levels listed health care providers as a primary source for support.</p> <p>Conclusions</p> <p>These findings suggest that there is considerable need for physical activity interventions in this population. Adults feel great responsibility for their own physical activity levels, but also attribute responsibility for promoting increased physical activity to health care practitioners.</p
Primary care nurses struggle with lifestyle counseling in diabetes care: a qualitative analysis
Contains fulltext :
89605.pdf (publisher's version ) (Open Access)BACKGROUND: Patient outcomes are poorly affected by lifestyle advice in general practice. Promoting lifestyle behavior change require that nurses shift from simple advice giving to a more counseling-based approach. The current study examines which barriers nurses encounter in lifestyle counseling to patients with type 2 diabetes. Based on this information we will develop an implementation strategy to improve lifestyle behavior change in general practice. METHOD: In a qualitative semi-structured study, twelve in-depth interviews took place with nurses in Dutch general practices involved in diabetes care. Specific barriers in counseling patients with type 2 diabetes about diet, physical activity, and smoking cessation were addressed. The nurses were invited to reflect on barriers at the patient and practice levels, but mainly on their own roles as counselors. All interviews were audio-recorded and transcribed. The data were analyzed with the aid of a predetermined framework. RESULTS: Nurses felt most barriers on the level of the patient; patients had limited knowledge of a healthy lifestyle and limited insight into their own behavior, and they lacked the motivation to modify their lifestyles or the discipline to maintain an improved lifestyle. Furthermore, nurses reported lack of counseling skills and insufficient time as barriers in effective lifestyle counseling. CONCLUSIONS: The traditional health education approach is still predominant in primary care of patients with type 2 diabetes. An implementation strategy based on motivational interviewing can help to overcome 'jumping ahead of the patient' and promotes skills in lifestyle behavioral change. We will train our nurses in agenda setting to structure the consultation based on prioritizing the behavior change and will help them to develop social maps that contain information on local exercise programs
Blood lipids and prostate cancer: a Mendelian randomization analysis
Genetic risk scores were used as unconfounded instruments for specific lipid traits (Mendelian randomization) to assess whether circulating lipids causally influence prostate cancer risk. Data from 22,249 prostate cancer cases and 22,133 controls from 22 studies within the international PRACTICAL consortium were analyzed. Allele scores based on single nucleotide polymorphisms (SNPs) previously reported to be uniquely associated with each of low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglyceride (TG) levels, were first validated in an independent dataset, and then entered into logistic regression models to estimate the presence (and direction) of any causal effect of each lipid trait on prostate cancer risk. There was weak evidence for an association between the LDL genetic score and cancer grade: the odds ratio (OR) per genetically instrumented standard deviation (SD) in LDL, comparing high- (≥7 Gleason score) versus low-grade (<7 Gleason score) cancers was 1.50 (95% CI: 0.92, 2.46; P = 0.11). A genetically instrumented SD increase in TGs was weakly associated with stage: the OR for advanced versus localized cancer per unit increase in genetic risk score was 1.68 (95% CI: 0.95, 3.00; P = 0.08). The rs12916-T variant in 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) was inversely associated with prostate cancer (OR: 0.97; 95% CI: 0.94, 1.00; P = 0.03). In conclusion, circulating lipids, instrumented by our genetic risk scores, did not appear to alter prostate cancer risk. We found weak evidence that higher LDL and TG levels increase aggressive prostate cancer risk, and that a variant in HMGCR (that mimics the LDL lowering effect of statin drugs) reduces risk. However, inferences are limited by sample size and evidence of pleiotropy
Effective DNA/RNA Co-Extraction for Analysis of MicroRNAs, mRNAs, and Genomic DNA from Formalin-Fixed Paraffin-Embedded Specimens
Background: Retrospective studies of archived human specimens, with known clinical follow-up, are used to identify predictive and prognostic molecular markers of disease. Due to biochemical differences, however, formalin-fixed paraffinembedded (FFPE) DNA and RNA have generally been extracted separately from either different tissue sections or from the same section by dividing the digested tissue. The former limits accurate correlation whilst the latter is impractical when utilizing rare or limited archived specimens. Principal Findings: For effective recovery of genomic DNA and total RNA from a single FFPE specimen, without splitting the proteinase-K digested tissue solution, we optimized a co-extraction method by using TRIzol and purifying DNA from the lower aqueous and RNA from the upper organic phases. Using a series of seven different archived specimens, we evaluated the total amounts of genomic DNA and total RNA recovered by our TRIzol-based co-extraction method and compared our results with those from two commercial kits, the Qiagen AllPrep DNA/RNA FFPE kit, for co-extraction, and the Ambion RecoverAll TM Total Nucleic Acid Isolation kit, for separate extraction of FFPE-DNA and-RNA. Then, to accurately assess the quality of DNA and RNA co-extracted from a single FFPE specimen, we used qRT-PCR, gene expression profiling and methylation assays to analyze microRNAs, mRNAs, and genomic DNA recovered from matched fresh and FFPE MCF10A cells. These experiments show that the TRIzol-based co-extraction method provides larger amounts of FFPE-DNA and –RNA tha
Syndromes with congenital brittle bones
BACKGROUND: There is no clear definition of osteogenesis imperfecta (OI). The most widely used classification of OI divides the disease in four types, although it has been suggested that there may be at least 12 forms of OI. These forms have been named with numbers, eponyms or descriptive names. Some of these syndromes can actually be considered congenital forms of brittle bones resembling OI (SROI). DISCUSSION: A review of different syndromes with congenital brittle bones published in the literature is presented. Syndromes are classified in "OI" (those secondary to mutations in the type I pro-collagen genes), and "syndromes resembling OI" (those secondary to mutations other that the type I pro-collagen genes, identified or not). A definition for OI is proposed as a syndrome of congenital brittle bones secondary to mutations in the genes codifying for pro-collagen genes (COL1A1 and COL1A2). SUMMARY: A debate about the definition of OI and a possible clinical and prognostic classification are warranted
Acclimatization of the crustose coralline alga Porolithon onkodes to variable pCO2
Ocean acidification (OA) has important implications for the persistence of coral reef ecosystems, due to potentially negative effects on biomineralization. Many coral reefs are dynamic with respect to carbonate chemistry, and experience fluctuations in pCO2 that exceed OA projections for the near future. To understand the influence of dynamic pCO2 on an important reef calcifier, we tested the response of the crustose coralline alga Porolithon onkodes to oscillating pCO2. Individuals were exposed to ambient (400 ??atm), high (660 ??atm), or variable pCO2 (oscillating between 400/660 ??atm) treatments for 14 days. To explore the potential for coralline acclimatization, we collected individuals from low and high pCO2 variability sites (upstream and downstream respectively) on a back reef characterized by unidirectional water flow in Moorea, French Polynesia. We quantified the effects of treatment on algal calcification by measuring the change in buoyant weight, and on algal metabolism by conducting sealed incubations to measure rates of photosynthesis and respiration. Net photosynthesis was higher in the ambient treatment than the variable treatment, regardless of habitat origin, and there was no effect on respiration or gross photosynthesis. Exposure to high pCO2 decreased P. onkodes calcification by >70%, regardless of the original habitat. In the variable treatment, corallines from the high variability habitat calcified 42% more than corallines from the low variability habitat. The significance of the original habitat for the coralline calcification response to variable, high pCO2 indicates that individuals existing in dynamic pCO2 habitats may be acclimatized to OA within the scope of in situ variability. These results highlight the importance of accounting for natural pCO2 variability in OA manipulations, and provide insight into the potential for plasticity in habitat and species-specific responses to changing ocean chemistry.Funding was provided by grants from the National Science Foundation (OCE-0417412, OCE-10-26852, OCE-1041270) and gifts from the Gordon and Betty Moore Foundation. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript
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