Distraction-Induced Intestinal Growth: The Role of Mechanotransduction Mechanisms in a Mouse Model of Short Bowel Syndrome

Novel strategies are needed to address the problem of patients with short bowel syndrome. We previously demonstrated a three-fold lengthening of pig bowel after 2 weeks of applied distractive forces, but we have not elucidated the mechanisms facilitating this growth. We used a mouse model of distraction-induced enterogenesis. High molecular weight polyethylene glycol (PEG) osmotically stretched an isolated small bowel segment (PEG-stretch). Significant increases in villus height and crypt depth and in intestinal epithelial cell length and numbers suggested epithelial remodeling in addition to proliferation during enterogenesis. LC-MS/MS analysis showed a two-fold upregulation of α-actinin-1 and -4. We also demonstrated that p-focal adhesion kinase (FAK), FAK, α-actinin, and Rac1 were significantly upregulated and that F-actin was relocalized in PEG-stretch versus controls. Blockade of the phosphotidyl inositol 3? kinase pathway failed to influence the increase in proliferation or decline in apoptosis after stretch, suggesting alternative signaling pathways are used, including MEK and P38MAPK, which were both upregulated during enterogenesis. Our data suggests that several known mechanotransduction pathways drive distraction-induced enterogenesis.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140227/1/ten.tea.2013.0383.pd

Quantification of lung perfusion blood volume by dual-energy CT in patients with and without chronic obstructive pulmonary disease

Purpose: In chronic obstructive pulmonary disease (COPD), pulmonary vascular alteration is one of the characteristic features. Recently, software has been used for the quantification of lung iodine perfusion blood volume (iPBV) using dual-energy CT, allowing objective evaluation. The purpose of this study was to evaluate the quantification of lung PBV with and without COPD. Materials and Methods: This study was approved by the Institutional Review Board. Sixty-two subjects who had undergone a respiratory function test within one month underwent dual-energy CT angiography. The subjects were divided into two groups: with (n=14) and without (n=48) COPD. We evaluated the quantification of lung iPBV in the early phase and late phase using Syngo softwarepost contrast. Associations between lung iPBV and respiratory function (forced expiratory volume in 1 second/forced vital capacity; FEV1/FVC) and the percentage area of emphysema (%LAA-950) were also evaluated. Results: In the early phase, lung iPBV values were 20.1±5.5 and 30.6±7.6 Hounsfield Unit (HU) in those with and without COPD, respectively, with a significant difference between them (Conclusions: Quantification of lung iPBV reflects reduced pulmonary perfusion in patients with COPD. It may be useful for objective evaluation of the pulmonary blood flow in patients with COPD

STUDI DASAR PELAPISAN INTERMETALLIC Al-Fe PADA PLAT BAJA DENGAN METODE MECHANICAL ALLOYING

STUDI DASAR PELAPISAN INTERMETALLIC Al-Fe PADA PLAT BAJA DENGAN METODE MECHANICAL ALLOYING. Akhir-akhir ini, pemaduan mekanik atau Mechanical Alloying (MA) mendapat perhatian akan kemampuannya untuk membentuk pelapisan pada permukaan partikel yang berstruktur nanometer. Struktur nanometer dapat memperbaiki berbagai sifat dari material seperti kecepatan difusi, dan keuletannya. Untuk mempelajari proses perubahan struktur pelapisan menggunakan metode Mechanical Alloying pada suhu kamar, dilakukan pelapisan dengan bubuk Al dan Al-25at% Fe (persen atom) pada plat baja dengan menggunakan planetary ball mill selama 80 jam, yang diatur suhunya dibawah 50 °C. Pelapisan bubuk Al tidak diperoleh, tetapi dengan penambahan 25at% Fe pelapisan dapat diperoleh. Penambahan Fe menstimulasi kristal Al untuk lebih mudah hancur dan menempel lebih baik. Ketebalan pelapisan yang terbentuk mencapai 250 μm. Pada Mechanical Alloying selama 80 jam, terbentuk amorf dari Al-25at% Fe dan intermetallic Al5Fe2

Phenobarbital Indirectly Activates the Constitutive Active Androstane Receptor (CAR) by Inhibition of Epidermal Growth Factor Receptor Signaling

Phenobarbital is a central nervous system depressant that also indirectly activates nuclear receptor constitutive active androstane receptor (CAR), which promotes drug and energy metabolism, as well as cell growth (and death), in the liver. We found that phenobarbital activated CAR by inhibiting epidermal growth factor receptor (EGFR) signaling. Phenobarbital bound to EGFR and potently inhibited the binding of EGF, which prevented the activation of EGFR. This abrogation of EGFR signaling induced the dephosphorylation of receptor for activated C kinase 1 (RACK1) at Tyr52, which then promoted the dephosphorylation of CAR at Thr38 by the catalytic core subunit of protein phosphatase 2A. The findings demonstrated that the phenobarbital-induced mechanism of CAR dephosphorylation and activation is mediated through its direct interaction with and inhibition of EGFR

Catchment geology preconditions spatio-temporal heterogeneity of ecosystem functioning in forested headwater streams

Catchment geology can affect water chemistry and groundwater influence, eventually affecting macroinvertebrate communities, but its effects on stream functions such as leaf decomposition have been scarcely investigated. To understand the effects of geology on leaf decomposition, we conducted leaf litter experiments in streams with volcanic and non-volcanic substrata using fine and coarse mesh bags. Volcanic spring-fed streams showed lower temperature in summer and higher temperature in winter (with temperature difference being more pronounced later in incubation) than non-volcanic streams. Macroinvertebrate communities captured inside coarse litter bags differed in the two stream types in both seasons, mainly because of shredder communities. Shredder abundance and biomass were higher in volcanic streams in both seasons. Geology-dependent temperature influenced microbe-mediated decomposition in both seasons, with total phosphorus as an additional driver in winter. Summer temperature was associated with an overall positive effect on the abundance of shredders, which affected invertebrate-mediated decomposition, but this was not evident in winter. Shredder activity in volcanic streams compensated for temperature-dependent microbial activity resulting in an overall balance in leaf decomposition. Spring-fed systems are valuable ecosystems, particularly for cold-adapted species. Thus, understanding these understudied ecosystems will significantly aid in their appropriate conservation