The creation of musculoskeletal tissue represents an alternative for the replacement of soft tissue in reconstructive surgery. However, most of the approaches of creating artificial tissue have their limitations in the size as the maximally obtainable dimension of bioartificial tissue (BAT) is limited due to the lack of supporting vessels within the 3-dimensional construct. The seeded myoblasts require high amounts of perfusion, oxygen, and nutrients to survive. To achieve this, we developed a 3-dimensional scaffold which features the epigastric artery as macroscopic core vessel inside the BAT in a rat model (perfused group, n = 4) and a control group (n = 3) without the epigastric vessels and, therefore, without perfusion. The in vivo monitoring of the transplanted myoblasts was assessed by bioluminescence imaging and showed both the viability of the epigastric artery within the 3-dimensional construct and again that cell survival in vivo is highly depending on the blood supply with the beginning of capillarization within the BAT seven days after transplantation in the perfused group. However, further studies focussing on the matrix improvement will be necessary to create a transplantable BAT with the epigastric artery as anastomosable vessel.

The amyloid cascade hypothesis on the pathogenesis of Alzheimer's disease (AD) states that amyloid β (Aβ) accumulation in the brain is a key factor that initiates the neurodegenerative process. Aβ is generated from amyloid precursor protein (APP) through sequential cleavages by BACE1 (the major β-secretase in the brain) and γ-secretase. The purpose of this study was to characterize APP metabolism in vivo in AD patients versus cognitively healthy subjects by examining alterations in cerebrospinal fluid (CSF) biomarkers. We measured BACE1 activity and concentrations of α- and β-cleaved soluble APP (sAPPα and sAPPβ, respectively) and Aβ40 in CSF, biomarkers that all reflect the metabolism of APP, in 75 AD patients and 65 cognitively healthy controls. These analytes were also applied in a multivariate model to determine whether they provided any added diagnostic value to the core CSF AD biomarkers Aβ42, T-tau, and P-tau. We found no significant differences in BACE1 activity or sAPPα, sAPPβ, and Aβ40 concentrations between AD patients and controls. A multivariate model created with all analytes did not improve the separation of AD patients from controls compared with using the core AD biomarkers alone, highlighting the strong diagnostic performance of Aβ42, T-tau, and P-tau for AD. However, AD patients in advanced clinical stage, as determined by low MMSE score (≤20), had lower BACE1 activity and sAPPα, sAPPβ, and Aβ40 concentrations than patients with higher MMSE score, suggesting that these markers may be related to the severity of the disease.

An in-depth understanding of the molecular and cellular complexity of angiogenesis continues to advance as new stimulators and inhibitors of blood vessel formation are uncovered. Gaining a more complete understanding of the response of blood vessels to both stimulatory and inhibitory molecules will likely contribute to more effective strategies to control pathological angiogenesis. Here, we provide evidence that endothelial cell interactions with structurally altered collagen type-IV may suppress the expression of Insulin-like Growth Factor Binding Protein-4 (IGFBP-4), a well-documented inhibitor of the IGF-1/IGF-1R signaling axis. We report for the first time that IGFBP-4 differentially inhibits angiogenesis induced by distinct growth factor signaling pathways as IGFBP-4 inhibited FGF-2 and IGF-1 stimulated angiogenesis, but failed to inhibit VEGF-induced angiogenesis. The resistance of VEGF-stimulated angiogenesis to IGFBP-4 inhibition appears to depend on sustained activation of p38 MAP kinase as blocking its activity restored the anti-angiogenic effects of IGFBP-4 on VEGF-induced blood vessel growth in vivo. These novel findings provide new insight into how blood vessels respond to endogenous inhibitors during angiogenesis stimulated by distinct growth factor signaling pathways.

Several recently published studies have suggested that decreasing VEGF levels result in placental oxidative stress in preeclampsia, although the question as to how decreased VEGF concentrations increase oxidative stress still remains unanswered. Here, we show that VEGF activated Nrf2, the main regulating factor of the intracellular redox balance, in the cytotrophic cell line BeWo. In turn, this activated the production of antioxidative enzymes thioredoxin, thioredoxin reductase, and heme oxygenase-1, which showed a decrease in their expression in the placentas of preeclamptic women. Nevertheless, this activation occurred without oxidative stress stimulus. As a consequence, the activation of Nrf2 protected BeWo cells against H(2)O(2)/Fe(2+)-induced oxidative damage. We further show that VEGF up-regulated the expression of itself. A positive feedback loop was described in which VEGF activated Nrf2 in an ERK1/2-dependent manner; the up-regulation of HO-1 expression by Nrf2 augmented the production of carbon monoxide, which in turn up-regulated VEGF expression. In conclusion, VEGF induces the Nrf2 pathway to protect against oxidative stress and, via a positive feedback loop, to elevate VEGF expression. Therefore, decreased VEGF bioavailability during preeclampsia may result in higher vulnerability to placental oxidative cell damage and a further reduction of VEGF bioavailability, a vicious circle that may end up in preeclampsia.

BACKGROUND Laryngopharyngeal reflux (LPR) can cause atypical symptoms, asthma, and pulmonary fibrosis. The aim of this study was to establish the normative data for LPR using hypopharyngeal multichannel intraluminal impedance-pH (HMII). METHODS Asymptomatic subjects underwent endoscopy followed by 24-h HMII using a specialized impedance catheter configured to detect LPR before and after a 2-week course of proton pump inhibitors (PPI). Subjects were excluded if they had esophageal pathology or a positive DeMeester score. A cohort of 24 LPR patients who had a complete response to treatment was used for comparison with the normative data. RESULTS Forty subjects were enrolled. Thirty-four subjects completed one, and 25 completed both HMII testing periods off and on PPI. There was no difference in the total number of reflux events between off and on PPI [22 (8-32) and 24 (10-28), respectively, p = 0.89]. The 95th percentiles of LPR off and on PPI were 0 and 1, respectively. All patients with treatment responsive LPR had pre-treatment HMII values of LPR greater than the 95th percentile. CONCLUSION LPR events are rare in an asymptomatic population. One or more LPR events should be considered abnormal in patients with LPR symptoms regardless of whether there is a positive DeMeester score.

Despite the importance of anhydrous ammonia (AA) and urea as nitrogen (N) fertilizer sources in the United States, there have been few direct comparisons of their effects on soil nitrous oxide (NO) and nitric oxide (NO) emissions. We compared N oxide emissions, yields, and N fertilizer recovery efficiency (NFRE) in a corn ( L.) production system that used three different fertilizer practices: urea that was broadcast and incorporated (BU) and AA that was injected at a conventional depth (0.20 m)(AAc) and at a shallower depth (0.10 m)(AAs). Averaged over 2 yr in an irrigated loamy sand in Minnesota, growing season NO emissions increased in the order BU < AAc < AAs. In contrast, NO emissions were greater with BU than with AAc or AAs. Emissions of NO ranged from 0.5 to 1.4 kg N ha (50-140 g N Mg grain), while NO emissions ranged from 0.2 to 0.7 kg N ha (20-70 g N Mg grain). Emissions of total N oxides (NO + NO) increased in the order AAc < BU < AAs. Despite having the greatest emissions of NO and total N oxides, the AAs treatment had greater NFRE compared with the AAc treatment. These results provide additional evidence that AA emits more NO, but less NO, than broadcast urea and show that practices to reduce NO emissions do not always improve N use efficiency.

Experimental animal studies have demonstrated that oxidative stress plays an essential role during ischemic stroke. In addition to oxidizing macromolecules leading to cell injury, oxidants are also involved in cell death/survival signal pathways and cause mitochondrial dysfunction. Nuclear factor erythroid 2-related factor 2 (Nrf2) represents one of the major regulators implicated in the endogenous defense system against oxidative stress. We have studied the expression and activation status of Nrf2 under stroke-like conditions using the temporary middle cerebral artery occlusion rat model. Inactive Nrf2 is proteasomal degraded within minutes but stabilized during activation. We analyzed Nrf2 activation and the resulting accumulation in post-ischemic rat brain cells using double immunofluorescence staining with antibodies directed against Nrf2 and cell type-specific markers. The core infarct region showed no obvious positive staining signal for Nrf2 24 h after the initiation of artery occlusion. However, Nrf2 immunoreactivity was detectable in the ipsilateral penumbra where microglia, astrocytes, and neurons contained Nrf2. Interestingly, Nrf2 was also significantly upregulated in neurons but not in other cell types of the unaffected contralateral site. These results provide strong evidence that Nrf2 is involved in acute stroke-dependent neurodegeneration in the penumbra but not core region and indicate the presence of a systemic Nrf2 activator independent from oxidative stress.

The practice of contemporary pain medicine is laced with a number of significant ethical challenges. Considerable difficulties include the overutilization of interventional procedures, the application of under-evidenced treatment modalities, and potentially superfluous opioid prescribing. As with many other fields in medicine, including orthopedic surgery, relationships with industry are both common and pervasive, and influence our medical practice through education, publications, and research. This article highlights these ethical challenges and broaches several physician-driven solutions: The Association for Medical Ethics, the Physicians Payment Sunshine inspired by it, and other non-legislative reforms are discussed.

High levels of circulating insulin-like growth factor-1 (IGF-1) have been associated with increased risk of several cancers. Regarding colorectal cancer, these associations are generally weak. We hypothesized that an increase in IGF-1 over time would be a stronger risk factor for cancer-related outcomes than the actual levels. In this analysis we utilized existing data from the Insulin Resistance and Atherosclerosis Study (IRAS). Circulating IGF-1 levels and molar ratios of IGF-1 to IGF binding protein 3 (IGFBP-3) were measured at three time points, within a 10-year follow-up period. We examined the associations of increase of the two variables with the presence of colorectal adenoma at the end of follow-up among participants with normal glucose tolerance at baseline. This included 143 individuals, from which 24 were diagnosed with adenomatous polyps. Although the mean levels of IGF-1 and IGF-1/IGFBP-3 decline with age, approximately 30% of the participants showed an increase of at least fifteen percent ("ever increase") in one or both of these variables, compared to baseline. We found a positive association between "ever increase" in IGF-1 or IGF-1/IGFBP-3 and the presence of colorectal adenoma: ORs were 3.81 (95% CI: 1.30-10.8) and 2.83 (95% CI: 1.00-8.22), respectively. No association was found when analyzing the actual levels of both variables at any time point. Our data suggest that an increase in circulating IGF-1 or IGF-1/IGFBP-3 may represent a disturbed GH/IGF1 homeostasis, which could favor the development of precancerous lesions, such as colorectal adenoma. © 2011 Wiley-Liss, Inc.