Prognostic diagnosis of the health status of an air-turbine dental handpiece rotor by using sound and vibration signals

This paper reports the diagnostic results of a free-running of air turbine dental handpiece (ATDH) with three rotor statuses by applying fast Fourier transform (FFT), Hilbert-Huang transform (HHT), and multiscale entropy (MSE) processes. The proposed method was tested under conditions of additional axial preload on the rotor and ceramic bearings with a damaged outer race supporting the rotor. A laser-Doppler vibrometer, condenser microphone, and portable MEMS system microphone were used to acquire the signals when the ATDH rotor features were changed. The results showed that changes in preload or malfunctioning ball bearings can be discriminated and abstracted using FFT and HHT to analyze the vibration frequencies. The experimental results showed that the proposed method can successfully predict the prognostic status of an ATDH rotor. The smart sensing of the health of the ATDH was achieved through a comparative evaluation of the MSE values. The proposed diagnostic method yielded satisfactory prognostic effectiveness in predicting the health status of the tested ATDH rotor

IL-6 regulates Mcl-1L expression through the JAK/PI3K/Akt/CREB signaling pathway in hepatocytes: implication of an anti-apoptotic role during liver regeneration.

AIMS: To investigate the role and the regulation of the long variant of myeloid cell leukemia-1 protein (Mcl-1L) during liver regeneration. BACKGROUND: Liver regeneration is an important phenomenon after liver injury. The rat partial hepatectomy (PH) model was used to characterize liver regeneration and Mcl-1L expression after PH. METHODS: Male Wistar rats were subjected to 70% PH. The expression of mcl-1L mRNA was determined by quantitative RT-PCR, and protein levels were analyzed by Western blot analysis and immunohistochemistry during liver regeneration. Functional evaluations of Mcl-1L were tested using chemical inhibition (flavopiridol), genetic inhibition (siRNA) of Mcl-1L production, and by assaying for annexin V levels and DNA ladder formation. Serum IL-6 levels were determined by enzyme immunoassays; signal transduction of IL-6-regulated Mcl-1L expression was verified by chemical inhibitors and decoy double-stranded oligodeoxynucleotides. RESULTS: High levels of Mcl-1L were observed in remnant tissue at 4 h after PH. Administration of flavopiridol decreased Mcl-1L accumulation and also inhibited liver regeneration. IL-6 administration promoted the accumulation of Mcl-1L in rat hepatocytes, an effect that was impaired by siRNA treatments that reduced Mcl-1L production. Chemical inhibition and decoy oligonucleotide competition demonstrated that IL-6-induced Mcl-1L production required signaling mediated by JAK kinase, phosphoinositide 3-kinase (PI3K), and cAMP response-element-binding (CREB) proteins. CONCLUSION: Mcl-1L is an anti-apoptotic protein induced during liver regeneration after PH in rats. The expression of Mcl-1L is induced by IL-6 through the JAK/PI3K/Akt/CREB signaling pathway. Chemotherapy drugs that depend on Mcl-1L- or IL-6-related signaling should be considered carefully before use in patients undergoing hepatectomy for malignant tumor resection

JAK/PI3K/Akt/CREB signaling is involved in IL-6-induced Mcl-1L expression in hepatocytes.

<p>(A) Rat hepatocytes were pretreated with chemical inhibitors, JAK Inhibitor InSolution™ 420097 (20 nM), for 1 h prior to IL-6 (10 ng/ml) treatment. After 4 h, the Mcl-1L protein levels were determined by Western blotting. Between-group comparisons are as indicated with *p<0.05. (B) Rat hepatocytes were pretreated with chemical inhibitors, LY294002 (50 µg/mL), PD98059 (50 µg/mL), and staurosporine (20 nM) for 1 h prior to IL-6 (10 ng/ml) treatment. After 4 h, Mcl-1L expression was analyzed by Western blotting. Between-group comparisons are as indicated. *p<0.05. (C) Rat hepatocytes were pretreated with the NF-κB and CREB decoy ODN (10 µM) for 24 h prior to IL-6 treatment. After 4 h, mcl-1 mRNA expression was analyzed by q-RT-PCR. Data are fold-induction relative to the control (Lane 1). Between-group comparisons are as indicated. *p<0.05. (D) Rat hepatocytes were pretreated with JAK Inhibitor InSolution™ 420097 (20 nM), or LY294002 (50 µg/mL) for 1 h prior to IL-6 treatment. After 30 minutes, p-Akt, Akt, p-CREB and CREB were determined by Western blotting. Between-group comparisons are as indicated. *p<0.05.</p

Lysophosphatidic acid alters the expression profiles of angiogenic factors, cytokines, and chemokines in mouse liver sinusoidal endothelial cells.

Lysophosphatidic acid (LPA) is a multi-function glycerophospholipid. LPA affects the proliferation of hepatocytes and stellate cells in vitro, and in a partial hepatectomy induced liver regeneration model, the circulating LPA levels and LPA receptor (LPAR) expression levels in liver tissue are significantly changed. Liver sinusoidal endothelial cells (Lsecs) play an important role during liver regeneration. However, the effects of LPA on Lsecs are not well known. Thus, we investigated the effects of LPA on the expression profiles of angiogenic factors, cytokines, and chemokines in Lsecs.Mouse Lsecs were isolated using CD31-coated magnetic beads. The mRNA expression levels of LPAR's and other target genes were determined by quantitative RT-PCR. The protein levels of angiogenesis factors, cytokines, and chemokines were determined using protein arrays and enzyme immunoassay (EIA). Critical LPAR related signal transduction was verified by using an appropriate chemical inhibitor.LPAR1 and LPAR3 mRNA's were expressed in mouse LPA-treated Lsecs. Treating Lsecs with a physiological level of LPA significantly enhanced the protein levels of angiogenesis related proteins (cyr61 and TIMP-1), cytokines (C5/C5a, M-CSF, and SDF-1), and chemokines (MCP-5, gp130, CCL28, and CXCL16). The LPAR1 and LPAR3 antagonist ki16425 significantly inhibited the LPA-enhanced expression of cyr61, TIMP-1, SDF-1, MCP-5, gp130, CCL28, and CXCL16, but not that of C5/C5a or M-CSF. LPA-induced C5/C5a and M-CSF expression may have been through an indirect regulation mechanism.LPA regulated the expression profiles of angiogenic factors, cytokines, and chemokines in Lsecs that was mediated via LPAR1 and LPAR3 signaling. Most of the factors that were enhanced by LPA have been found to play critical roles during liver regeneration. Thus, these results may prove useful for manipulating LPA effects on liver regeneration

Changes in the ratio of remnant liver weight to original liver weight (RLW/OLW) after 70% partial hepatectomy (PH).

<p>(A) OLW was estimated retrospectively from the excised liver weight after 70% PH. Data are presented as mean ± S.D., and comparisons were made between groups as indicated. *P<0.05. (B) ki67 staining of remnant liver tissue. Magnification, 400×.</p

Schematic of the proposed signal transduction pathway of Mcl-1L induction in hepatocytes during liver regeneration.

<p>IL-6 regulates Mcl-1L expression through the IL-6 dependent JAK/PI3K/Akt/CREB activation pathway in rat hepatocytes.</p

mRNA and protein expression of Mcl-1L during liver regeneration.

<p>Remnant liver tissue from the indicated time points was used to determine (A) mcl-1 mRNA expression by q-RT-PCR; *P<0.05 and (B) protein levels of Mcl-1L as detected by Western blotting. (C) Parafilm sections of the remnant liver were used for Mcl-1 detection by IHC. Magnification, 400×.</p

IL-6 induced Mcl-1L expression in rat hepatocytes.

<p>(A) Serum levels of IL-6 in PH rats or flavopiridol (2.5 mg/kg) treated for 24 hours before PH group or control group were determined by EIA. Data are provided as mean +/− S.D. *P<0.05. (B) Rat hepatocytes were serum-starved for 24 hours prior treated with recombinant rat IL-6 (0.1, 1 and 10 ng/ml), under serum-starved conditions, and after 4 hours, Mcl-1L protein levels were determined by Western blot analysis. (C) Rat hepatocytes were serum-starved for 24 hours prior treated with recombinant rat IL-6 ( 1 ng/ml), under serum-starved conditions, at the indicated time periods, Mcl-1L protein levels were determined by Western blot analysis. (D) Rat hepatocytes were treated with rat recombinant IL-6 (10 ng/ml) at the indicated time periods. Mcl-1 mRNA expression in rat hepatocytes was determined by q-RT-PCR. *P<0.05.</p

Mcl-1L chemical inhibitor flavopiridol inhibits liver regeneration in rats.

<p>(A) Rats were pretreated with flavopiridol (2.5 mg/kg) or vehicle (control) 24 hours before partial hepatectomy (PH). (A) The remnant liver weight (RLW) of each group was measured at the indicated time periods after PH and expressed as a percentage of the original liver weight (OLW). Data are compared between the vehicle and flavopiridol-treated groups. *P<0.05. (B) The expression of Mcl-1L in remnant liver tissue was determined by IHC. (C) ki67 staining. (D) TUNEL staining. Magnification, 400×.</p

IL-6 induced Mcl-1L expression plays an anti-apoptotic role in hepatocytes.

<p>(A) Rat hepatocytes were pretreated with mcl-1L siRNA (25 nM) or control siRNA (25 nM) for 24 h prior to IL-6 (10 ng/ml) treatment; four hours later, Mcl-1L levels were determined by Western blot analysis. Between-group comparisons are as indicated. *p<0.05. (B) Rat hepatocytes were pretreated with mcl-1L siRNA or control siRNA for 24 h prior to IL-6 treatment or not in serum-free conditions for another 48 hours. The percentage of apoptotic hepatocytes were determined by annexin-V staining. The illustration shown represents one of three independent experiments. (C) Quantitative result of annexin-V staining. Between-group comparisons are as indicated. *p<0.05. (D) Similar treatment protocol as described in (C), another 72 hours. DNA ladder analysis was performed. The illustration shown is representative of three independent experiments.</p