Expression of myogenic regulatory factors in chicken embryos during somite and limb development

The expression of the myogenic regulatory factors (MRFs), Myf5, MyoD, myogenin (Mgn) and MRF4 have been analysed during the development of chicken embryo somites and limbs. In somites, Myf5 is expressed first in somites and paraxial mesoderm at HH stage 9 followed by MyoD at HH stage 12, and Mgn and MRF4 at HH stage 14. In older somites, Myf5 and MyoD are also expressed in the ventrally extending myotome prior to Mgn and MRF4 expression. In limb muscles a similar temporal sequence is observed with Myf5 expression detected first in forelimbs at HH stage 22, MyoD at HH stage 23, Mgn at HH stage 24 and MRF4 at HH stage 30. This report describes the precise time of onset of expression of each MRF in somites and limbs during chicken embryo development, and provides a detailed comparative timeline of MRF expression in different embryonic muscle groups.     

A brief adherence intervention that improved glycemic control: mediation by patterns of adherence

Journal of Behavioral Medicine - This study examined whether longitudinal adherence profiles mediated the relationship between a brief adherence intervention and glycemic control among patients...     

Discharge diagnoses versus medical record review in the identification of community-acquired sepsis

IntroductionWe evaluated the accuracy of hospital discharge diagnoses in the identification of community-acquired sepsis and severe sepsis.MethodsWe reviewed 379 serious infection hospitalizations from 2003 to 2012 from the national population-based reasons for geographic and racial differences in stroke (REGARDS) cohort. Through manual review of medical records, we defined criterion-standard community-acquired sepsis events as the presence of a serious infection on hospital presentation with ≥2 systemic inflammatory response syndrome criteria. We also defined criterion-standard community-acquired severe sepsis events as sepsis with >1 sequential organ failure assessment organ dysfunction. For the same hospitalizations, we identified sepsis and severe sepsis events indicated by Martin et al. and Angus et al. International Classifications of Diseases 9th edition discharge diagnoses. We evaluated the diagnostic accuracy of the Martin and Angus criteria for detecting criterion-standard community-acquired sepsis and severe sepsis events.ResultsAmong the 379 hospitalizations, there were 156 community-acquired sepsis and 122 community-acquired severe sepsis events. Discharge diagnoses identified 55 Martin-sepsis and 89 Angus-severe sepsis events. The accuracy of Martin-sepsis criteria for detecting community-acquired sepsis were: sensitivity 27.6%; specificity 94.6%; positive predictive value (PPV) 78.2%; negative predictive value (NPV) 65.1%. The accuracy of the Angus-severe sepsis criteria for detecting community-acquired severe sepsis were: sensitivity 42.6%; specificity 86.0%; PPV 58.4%; NPV 75.9%. Mortality was higher for Martin-sepsis than community-acquired sepsis (25.5% versus 10.3%, P = 0.006), as well as for Angus-severe sepsis than community-acquired severe sepsis (25.5 versus 11.5%, P = 0.002). Other baseline characteristics were similar between sepsis groups.ConclusionsHospital discharge diagnoses show good specificity but poor sensitivity for detecting community-acquired sepsis and severe sepsis. While sharing similar baseline subject characteristics as cases identified by hospital record review, discharge diagnoses selected for higher mortality sepsis and severe sepsis cohorts. The epidemiology of a sepsis population may vary with the methods used for sepsis event identification.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-0771-6) contains supplementary material, which is available to authorized users.     

Hypoxia induces a lipogenic cancer cell phenotype via HIF1α-dependent and -independent pathways

The biochemistry of cancer cells diverges significantly from normal cells as a result of a comprehensive reprogramming of metabolic pathways. A major factor influencing cancer metabolism is hypoxia, which is mediated by HIF1α and HIF2α. HIF1α represents one of the principal regulators of metabolism and energetic balance in cancer cells through its regulation of glycolysis, glycogen synthesis, Krebs cycle and the pentose phosphate shunt. However, less is known about the role of HIF1α in modulating lipid metabolism. Lipids serve cancer cells to provide molecules acting as oncogenic signals, energetic reserve, precursors for new membrane synthesis and to balance redox biological reactions. To study the role of HIF1α in these processes, we used HCT116 colorectal cancer cells expressing endogenous HIF1α and cells in which the hif1α gene was deleted to characterize HIF1α-dependent and independent effects on hypoxia regulated lipid metabolites. Untargeted metabolomics integrated with proteomics revealed that hypoxia induced many changes in lipids metabolites. Enzymatic steps in fatty acid synthesis and the Kennedy pathway were modified in a HIF1α-dependent fashion. Palmitate, stearate, PLD3 and PAFC16 were regulated in a HIF-independent manner. Our results demonstrate the impact of hypoxia on lipid metabolites, of which a distinct subset is regulated by HIF1α.     

A metabolic interpretation for the response of cellular autofluorescence to chemical perturbations assessed using spectral phasor analysis

Analytical approaches for sensing cellular NADH conformation from autofluorescence signals have significance because NADH is a metabolic indicator and endogenous biomarker. Recently, spectral detection of multiple cellular NADH forms during chemically-induced metabolic response was reported, however because NADH is solvatochromic and the spectral change is small, the possibility of a non-metabolic interpretation needs to be considered. Here we investigate the response of UV-excited autofluorescence to a range of well-known chemicals affecting fermentation, respiration, and oxidative-stress pathways in Saccharomyces cerevisiae. The two-component nature of the spectral response is assessed using phasor analysis. By considering a series of physically similar and dissimilar chemicals acting on multiple pathways, we show how the two-component nature of a spectral response is of metabolic origin, indicative of whether a single or several pathways have been affected.

The two-component nature of the autofluorescence response is indicative of whether a single or several pathways are affected.

Cellular reduced nicotinamide adenine dinucleotide (NADH) exists in multiple conformations, which is significant because the proportions of these forms respond differently to metabolic conditions.^1–3 Real-time metabolic monitoring approaches sensitive to cellular NADH conformation therefore have bioanalytical significance, e.g., in using NADH as a metabolic indicator and endogenous biomarker,^1–9 in monitoring cytotoxicity,^10,11 or in investigating NADH/reduced nicotinamide adenine dinucleotide phosphate (NADPH) balance.^12,13Although excited-state, energy-transfer, and anisotropy-decay measurements on fluorescence signals provide direct physical measures of conformation,^1,14,15 we reported the spectral detection of multiple cellular NADH forms,¹⁶ of interest due to the wide availability and straightforward implementation of spectroscopic methods. By quantifying spectrum shape using spectral phasor analysis, changes in UV-excited autofluorescence spectra in response to different NADH-oxidation inhibitors (i.e., ethanol and cyanide) were distinguishable and could not be accounted for using a two-component (e.g., free vs. bound) model for excited-state emission. Therefore, we proposed an interpretation in which the non-two-component behavior in spectrum shape during a metabolic response was due to the redistribution of NADH forms associated with the multiple NADH-utilizing pathways.¹⁶Note a phasor analysis for fluorescence lifetime signals is well established^17–19 with a graphical representation useful in assessing the composition of complex systems and in distinguishing metabolic states in cells.^20–23 Here, a spectral phasor analysis, initially developed for the rapid identification of regions within hyperspectral images^24,25 and increasingly used in imaging studies of biological systems,^26–30 is used for the assessment of two-component behavior in the emission signal.Because NADH is solvatochromic and because conformations have emission with significant spectral overlap,³¹ factors not indicative of a metabolic response but still affecting emission spectrum shape are possible, and so a pathway-level interpretation needs to be demonstrated over a broad range of metabolic responses. By chemically affecting fermentation, respiration, and oxidative-stress pathways in S. cerevisiae (baker''s yeast), we show here how changes in UV-excited autofluorescence spectrum shape are better interpreted as having metabolic rather than non-metabolic origins (e.g., due to the polarity of the added chemical).First, we present a direct illustration of metabolic-pathway discrimination by demonstrating how sequentially-induced responses affecting the same pathway follow two-component behavior, while responses affecting different pathways show non-two-component behavior. Next, to help rule out a non-metabolic interpretation, we show how the same chemical (i.e., cyanide) induces an autofluorescence response dependent on incubation in glucose, producing a non-two-component response consistent with having different initial metabolic states. Conversely, we show how chemicals of differing polarities (i.e., various alcohols) induce autofluorescence responses which collectively follow two-component behavior, in agreement with the alcohols having similar modes of metabolic action.To illustrate a situation where the chemical added is known to interact with the fluorophore, we show how metabolic effects of 2-thenoyltrifluoroacetone (TTFA) can be observed despite TTFA acting as a fluorescence quencher. Finally, we explore a potential application by comparing NADPH- and NADH-related responses through sequential chemical perturbations inducing either oxidative stress or respiratory inhibition.     

Systematic Review and Neural Network Analysis to Define Predictive Variables in Implantable Motor Cortex Stimulation to Treat Chronic Intractable Pain

Implantable motor cortex stimulation (iMCS) has been performed for >25 years to treat various intractable pain syndromes. Its effectiveness is highly variable and, although various studies revealed predictive variables, none of these were found repeatedly. This study uses neural network analysis (NNA) to identify predictive factors of iMCS treatment for intractable pain. A systematic review provided a database of patient data on an individual level of patients who underwent iMCS to treat refractory pain between 1991 and 2017. Responders were defined as patients with a pain relief of >40% as measured by a numerical rating scale (NRS) score. NNA was carried out to predict the outcome of iMCS and to identify predictive factors that impacted the outcome of iMCS. The outcome prediction value of the NNA was expressed as the mean accuracy, sensitivity, and specificity. The NNA furthermore provided the mean weight of predictive variables, which shows the impact of the predictive variable on the prediction. The mean weight was converted into the mean relative influence (M), a value that varies between 0 and 100%. A total of 358 patients were included (202 males [56.4%]; mean age, 54.2 ±13.3 years), 201 of whom were responders to iMCS. NNA had a mean accuracy of 66.3% and a sensitivity and specificity of 69.8% and 69.4%, respectively. NNA further identified 6 predictive variables that had a relatively high M: 1) the sex of the patient (M = 19.7%); 2) the origin of the lesion (M = 15.1%); 3) the preoperative numerical rating scale score (M = 9.2%); 4) preoperative use of repetitive transcranial magnetic stimulation (M = 7.3%); 5) preoperative intake of opioids (M = 7.1%); and 6) the follow-up period (M = 13.1%). The results from the present study show that these 6 predictive variables influence the outcome of iMCS and that, based on these variables, a fair prediction model can be built to predict outcome after iMCS surgery.PerspectiveThe presented NNA analyzed the functioning of computational models and modeled nonlinear statistical data. Based on this NNA, 6 predictive variables were identified that are suggested to be of importance in the improvement of future iMCS to treat chronic pain.     

Volumetric navigators for prospective motion correction and selective reacquisition in neuroanatomical MRI

We introduce a novel method of prospectively compensating for subject motion in neuroanatomical imaging. Short three-dimensional echo-planar imaging volumetric navigators are embedded in a long three-dimensional sequence, and the resulting image volumes are registered to provide an estimate of the subject's location in the scanner at a cost of less than 500 ms, ~ 1% change in contrast, and ~3% change in intensity. This time fits well into the existing gaps in sequences routinely used for neuroimaging, thus giving a motion-corrected sequence with no extra time required. We also demonstrate motion-driven selective reacquisition of k-space to further compensate for subject motion. We perform multiple validation experiments to evaluate accuracy, navigator impact on tissue intensity/contrast, and the improvement in final output. The complete system operates without adding additional hardware to the scanner and requires no external calibration, making it suitable for high-throughput environments.     

Metastatic melanoma to the heart

Melanoma is a common neoplasm with a propensity to metastasize to the heart. Although cardiac metastasis is rarely diagnosed ante mortem, using a multimodality approach, several imaging findings may be seen. Echocardiography is often the initial imaging method used to detect cardiac metastases and their complications. On computed tomography, intraluminal filling defects and myocardial/pericardial nodules may be seen. On magnetic resonance imaging, metastatic melanoma is classically hyperintense on T1 images and hypointense on T2 images, a result of the T1 shortening of melanin; however, this is seen in a minority of cases. As melanoma metastases are fluorine-18-fluorodeoxyglucose avid, fluorine-18-fluorodeoxyglucose positron emission tomography may also be used to detect cardiac metastases.     

Two Minutes of Sprint-Interval Exercise Elicits 24-hr Oxygen Consumption Similar to That of 30 min of Continuous Endurance Exercise

Six weeks (3 times/wk) of sprint-interval training (SIT) or continuous endurance training (CET) promote body-fat losses despite a substantially lower training volume with SIT. In an attempt to explain these findings, the authors quantified VO2 during and after (24 h) sprint-interval exercise (SIE; 2 min exercise) vs. continuous endurance exercise (CEE; 30 min exercise). VO2 was measured in male students (n = 8) 8 times over 24 hr under 3 treatments (SIE, CEE, and control [CTRL, no exercise]). Diet was controlled. VO2 was 150% greater (p < .01) during CEE vs. SIE (87.6 ± 13.1 vs. 35.1 ± 4.4 L O2; M ± SD). The observed small difference between average exercise heart rates with CEE (157 ± 10 beats/min) and SIE (149 ± 6 beats/min) approached significance (p = .06), as did the difference in peak heart rates during CEE (166 ± 10 beats/min) and SIE (173 ± 6 beats/min; p = .14). Total O2 consumed over 8 hr with CEE (263.3 ± 30.2 L) was greater (p < .01) than both SIE (224.2 ± 15.3 L; p < .001) and CTRL (163.5 ± 16.1 L; p < .001). Total O2 with SIE was also increased over CTRL (p < .001). At 24 hr, both exercise treatments were increased (p < .001) vs. CTRL (CEE = 500.2 ± 49.2; SIE = 498.0 ± 29.4; CTRL = 400.2 ± 44.6), but there was no difference between CEE and SIE (p = .99). Despite large differences in exercise VO2, the protracted effects of SIE result in a similar total VO2 over 24 hr vs. CEE, indicating that the significant body-fat losses observed previously with SIT are partially due to increases in metabolism postexercise.