An ontogenic study of adrenomedullin gene expression in the rat lung, adrenal, kidney, and heart

In this study, the gene expression of adrenomedullin (Adm) in the peripheral tissues which include lung, adrenal, kidney, and heart during development was investigated in the rat. The preproadrenomedullin (preproAdm) mRNA and mRNAs of its related receptor components, calcitonin receptor-like receptor (Crlr), and receptor activity-modifying proteins (Ramp1, 2 and 3) of the lung, adrenal, kidney, and heart were measured by real-time RT-PCR and the ADM peptide measured by radioimmunoassay in 1-, 7-, 21-day-old rats and the adult rats. From day 1 to 21, preproAdm mRNA levels increased with age in the lung, the kidney, and the heart but decreased with age in the adrenal. ADM levels, however, increased with age in the lung but decreased with age in the kidney, the adrenal, and the heart. The preproAdm levels in the lung, in the kidney, and in the adrenal all increased in the adult rat. ADM peptide levels, however, decreased in the adult rat. Crlr and Ramp2 gene expression increased with age in the lung, in the kidney, and in the heart but decreased with age in the adrenal in the prepubertal rats. The results indicate that the levels of preproAdm mRNA, ADM peptide and its receptor component mRNAs in different tissues followed different patterns of changes during development.

Development of an evaluation function for eye-hand coordination robotic therapy

This paper is the continuation of a work presented at ICORR 07, in which we discussed the possibility of improving eye-hand coordination in children diagnosed with this problem, using a robotic mapping from a haptic user interface to a virtual environment. Our goal is to develop, implement and refine a system that will assess and improve the eye-hand coordination and grip strength in children diagnosed with poor graphomotor skills. A detailed analysis of patters (e.g., labyrinths, letters and angles) was conducted in order to select three very distinguishable levels of difficulty that could be included in the system, and which would yield the greatest benefit in terms of assessment of coordination and strength issues as well as in training. Support algorithms (position, force, velocity, inertia and viscosity) were also developed and incorporated into the tasks in order to introduce general computer assistance to the mapping of the user's movements to the computer screen without overriding the user's commands to the robotic device. In order to evaluate performance (given by %accuracy and time) of the executed tasks, a sophisticated evaluation function was designed based on image analysis and edge detection algorithms. This paper presents the development of the haptic tasks, the various assistance algorithms, the description of the evaluation function and the results of a study implemented at the Motor Development Clinic at Cal Poly Pomona. The results (Accuracy and Time) of this function are currently being used as inputs to an Intelligent Decision Support System (described in), which in turn, suggests the next task to be executed by the subject based on his/her performance.

A Prototype TOF PET Detector Module Using a Micro-Channel Plate Photomultiplier Tube with Waveform Sampling

We are exploring a large area flat panel micro-channel plate photomultiplier tube (MCP PMT) under development for an application to time-of-flight positron emission tomography (TOF PET). High speed waveform sampling with transmission-lines is adopted for reading out the signal with precise time and space information with a small number of low-power channels. As a demonstration of the concept, detector modules have been built using 2″×2″ Photonis Planacon MCP PMTs (XP85022) and prototype transmission-line (TL) boards. The signals from the MCP PMT through the transmission-lines are sampled by DRS4 evaluation boards running at 5 giga-samples per second (GS/s). The event information is extracted by processing the digitized waveforms. For experimental tests, a single 3×3×10 mm(3) LYSO crystal is optically coupled to each MCP PMT; the detector responses to 511 keV annihilation photon from a (22)Na source are measured using the data taken in coincidence mode. As a preliminary result, we obtain a position resolution of ∼2.8 mm (0.3 mm) (FWHM) along (perpendicular to) the transmission-line, ∼309 ps (FWHM) for coincidence time resolution, and ∼14% (FWHM) of energy resolution at 511 keV. This initial result gives a promise that the large area MCP PMT is applicable to TOF PET.

Critical role of γ4 chain in the expression of functional Vγ4Vδ1 T cell receptor of gastric tumour-infiltrating γδT lymphocytes

Vγ4Vδ1 T cell receptor (TCRγ4δ1)-expressing γδT cells were the most dominant subset in gastric tumour-infiltrating γδT cells (γδTIL) we recently analyzed. To study the essential roles of γ and δ chains in assembly and function of TCRγ4δ1, we sequenced and constructed them into lentiviral vectors for the reconstitution of TCRγ4δ1 using different modalities of transduction. We were able to efficiently reconstitute TCRγ4δ1 with functional activities when both γ4 and δ1 chains are coexpressed in TCR-negative J.RT3-T3.5 cells. However, the expression of δ1 chain is greatly diminished when γ4 expression is absent, suggesting that the coexpressing γ4 is critical in maintaining the folding and stability of δ1 product. To functionally study the reconstituted TCRγ4δ1, we examined the cytolytic activity of TCRγ4δ1-reconstituted J.RT3-T3.5 cells and cytokine secretion and found the receptors are fully functional, but their functionality also requires the presence of γ4. Our results demonstrated that γ4 is critical for the stability of δ1 and the function of TCRγ4δ1.

Large eddy simulation of pollutant gas dispersion with buoyancy ejected from building into an urban street canyon

The dispersion of buoyancy driven smoke soot and carbon monoxide (CO) gas, which was ejected out from side building into an urban street canyon with aspect ratio of 1 was investigated by large eddy simulation (LES) under a perpendicular wind flow. Strong buoyancy effect, which has not been revealed before, on such pollution dispersion in the street canyon was studied. The buoyancy release rate was 5 MW. The wind speed concerned ranged from 1 to 7.5m/s. The characteristics of flow pattern, distribution of smoke soot and temperature, CO concentration were revealed by the LES simulation. Dimensionless Froude number (Fr) was firstly introduced here to characterize the pollutant dispersion with buoyancy effect counteracting the wind. It was found that the flow pattern can be well categorized into three regimes. A regular characteristic large vortex was shown for the CO concentration contour when the wind velocity was higher than the critical re-entrainment value. A new formula was theoretically developed to show quantitatively that the critical re-entrainment wind velocities, u(c), for buoyancy source at different floors, were proportional to -1/3 power of the characteristic height. LES simulation results agreed well with theoretical analysis. The critical Froude number was found to be constant of 0.7.

Andrographolide inhibits oral squamous cell carcinogenesis through NF-κB inactivation

The NF-κB family of transcription factors is essential for promoting cell proliferation and preventing cell apoptosis. We have previously shown that Andrographolide (Andro) isolated from an herbal plant, Andrographis paniculata, covalently modifies reduced cysteine(62) in the oligonucleotide binding pocket of p50 for inhibition of NF-κB activation. Here we report that Andro, but not its inactive structural analog 4H-Andro, potently suppressed squamous cell carcinogenesis induced by 7,12-dimethyl-1,2-benzanthracene (DMBA) in the hamster model of cheek buccal pouch. Compared with 4H-Andro, Andro reduced phosphorylation of p65 (Ser536) and IκBα (Ser32/36) for inhibiting aberrant NF-κB activation, suppressed c-Myc and cyclin D1 expression and attenuated neoplastic cell proliferation, promoted cancerous cell apoptosis, and mitigated tumor-induced angiogenesis. Consistently, Andro retarded growth, decreased proliferation, and promoted apoptosis of Tb cells, a human tongue squamous cell carcinoma cell line, in time- and dose-dependent manners, with concomitant reduction of the expression of NF-κB targeting molecules in vitro. Our results thus demonstrate that NF-κB activation plays important roles in the pathogenesis of chemically induced squamous cell carcinoma. By inhibition of aberrant NF-κB activation, Andro treats chemically induced oral squamous cell carcinogenesis.

AFOMP Policy Statement No. 3: recommendations for the education and training of medical physicists in AFOMP countries

AFOMP recognizes that clinical medical physicists should demonstrate that they are competent to practice their profession by obtaining appropriate education, training and supervised experience in the specialties of medical physics in which they practice, as well as having a basic knowledge of other specialties. To help its member countries to achieve this, AFOMP has developed this policy to provide guidance when developing medical physicist education and training programs. The policy is compatible with the standards being promoted by the International Organization for Medical Physics and the International Medical Physics Certification Board.

Adrenomedullin increases ciliary beat frequency and decreases muscular contraction in the rat oviduct

Our laboratory previously showed that oviduct produced the greatest amount of adrenomedullin (ADM) in the rat female reproductive tract. The aim of this study is to investigate the changes in ADM levels resulting from the contact between the sperm and the oviduct and the possible roles of ADM in ciliary beating and oviductal contractility. Oviducts from Sprague–Dawley rats removed at pre- and post-ovulatory stages were cut open longitudinally and treated with ADM and/or receptor blockers before ciliary beat frequency (CBF) was measured. The effects of sperm on ADM production and CBF in the oviduct were also determined. The contraction of the oviduct after treatment with ADM and receptor antagonists was measured using the organ-bath technique. The results showed that ADM increased the CBF in rat oviduct and this stimulating effect was blocked by the calcitonin-gene-related peptide (CGRP) receptor antagonist, hCGRP8–37. CBF was lower in post-ovulatory than pre-ovulatory oviducts. The presence of sperm in the oviduct increased both the ADM level and CBF. ADM treatment was shown to inhibit the contractility of the oviduct by lowering the basal tone and decreasing the contraction amplitude. The ADM receptor antagonist, hADM22–52, was effective in counteracting the relaxation effect of ADM in the oviduct. All in all, these results indicate that ADM may play a crucial role in transporting the gametes/embryos by regulating ciliary beating and muscular contraction.

Co-adjuvant effects of retinoic acid and IL-15 induce inflammatory immunity to dietary antigens

Under physiological conditions the gut-associated lymphoid tissues not only prevent the induction of a local inflammatory immune response, but also induce systemic tolerance to fed antigens. A notable exception is coeliac disease, where genetically susceptible individuals expressing human leukocyte antigen (HLA) HLA-DQ2 or HLA-DQ8 molecules develop inflammatory T-cell and antibody responses against dietary gluten, a protein present in wheat. The mechanisms underlying this dysregulated mucosal immune response to a soluble antigen have not been identified. Retinoic acid, a metabolite of vitamin A, has been shown to have a critical role in the induction of intestinal regulatory responses. Here we find in mice that in conjunction with IL-15, a cytokine greatly upregulated in the gut of coeliac disease patients, retinoic acid rapidly activates dendritic cells to induce JNK (also known as MAPK8) phosphorylation and release the proinflammatory cytokines IL-12p70 and IL-23. As a result, in a stressed intestinal environment, retinoic acid acted as an adjuvant that promoted rather than prevented inflammatory cellular and humoral responses to fed antigen. Altogether, these findings reveal an unexpected role for retinoic acid and IL-15 in the abrogation of tolerance to dietary antigens.

A theoretical study on accurate measurements of thoron with airflow-through scintillation cell method

For accurate measurements of (220)Rn concentration with airflow-through scintillation cell method, a theoretical study was performed for discussing the influences of sampling flow rate, volumes of sampling tube and scintillation cell on the measurements. It is found that a high flow rate and a large inner volume of scintillation cell as well as a small inner volume of sampling tube are not only preferable for measuring low levels of (220)Rn, but also helpful for enhancing the measurement accuracy. In calibration experiments, both the sampling flow rate and the sampling tube volume should be noted. The variations of the flow rate and tube volume should be considered for accurate measurements in the fields.

Involvement of NF-κB/miR-448 regulatory feedback loop in chemotherapy-induced epithelial-mesenchymal transition of breast cancer cells

The epithelial-mesenchymal transition (EMT) induced by chemotherapeutic agents promotes malignant tumor progression; however, the mechanism underlying the drug-induced EMT remains unclear. In this study, we reported that miR-448 is the most downregulated microRNA following chemotherapy. Suppression of miR-448 correlated with EMT induction in breast cancer in vitro and in vivo. With the use of chromatin immunoprecipitation-seq analysis, we demonstrated that miR-448 suppression induces EMT by directly targeting special AT-rich sequence-binding protein-1 (SATB1) mRNA, leading to elevated levels of amphiregulin and thereby, increasing epidermal growth factor receptor (EGFR)-mediated Twist1 expression, as well as nuclear factor κB (NF-κB) activation. On the other hand, we also found that the adriamycin-activated NF-κB directly binds the promoter of miR-448 suppressing its transcription, suggesting a positive feedback loop between NF-κB and miR-448. Furthermore, all patients who received cyclophosphamide (CP), epirubicin plus taxotere/CP, epirubicin plus 5-fluorouracil chemotherapy showed miR-448 suppression, an increased SATB1, Twist1 expression and acquisition of mesenchymal phenotypes. These findings reveal an underlying regulatory pathway, in which the autoregulation between NF-κB and miR-448 is important for restrain miR-448 suppression upon chemotherapy and may have a role in the regulation of chemotherapy-induced EMT. Disruption of the NF-κB-miR-448 feedback loop during clinical treatment may improve the chemotherapy response of human breast cancers in which EMT is a critical component.

Adrenomedullin regulates sperm motility and oviductal ciliary beat via cyclic adenosine 5'-monophosphate/protein kinase A and nitric oxide

Cilium and flagellum beating are important in reproduction and defects in their motion are associated with ectopic pregnancy and infertility. Adrenomedullin (ADM) is a polypeptide present in the reproductive system. This report demonstrates a novel action of ADM in enhancing the flagellar/ciliary beating of human spermatozoa and rat oviductal ciliated cells. At the concentration found in the seminal plasma, it increases the progressive motility of spermatozoa. ADM binds to its classical receptor, calcitonin receptor-like receptor/receptor activity-modifying protein complex on spermatozoa. ADM treatment increases the protein kinase A activities, the cyclic adenosine monophosphate, and nitric oxide levels of spermatozoa and oviductal cells. Pharmacological activators and inhibitors confirmed that the ADM-induced flagella/ciliary beating was protein kinase A dependent. Whereas nitric oxide donors had no effect on sperm motility, they potentiated the motility-inducing action of protein kinase A activators, demonstrating for the first time the synergistic action of nitric oxide and protein kinase A signaling in flagellar/ciliary beating. The ADM-induced motility enhancement effect in spermatozoa also depended on the up-regulation of intracellular calcium, a known key regulator of sperm motility and ciliary beating. In conclusion, ADM is a common activator of flagellar/ciliary beating. The study provides a physiological basis on possible use of ADM as a fertility regulation drug.

A role of Miz-1 in Gfi-1-mediated transcriptional repression of CDKN1A

Zinc-finger (ZF) transcriptional repressor Gfi-1 plays an important role in hematopoiesis and inner ear development, and also functions as an oncoprotein that cooperates with c-Myc in lymphomagenesis. Gfi-1 represses transcription by directly binding to conserved sequences in the promoters of its target genes. CDKN1A encoding p21^Cip1 has been identified as a Gfi-1 target gene and shown to contain Gfi-1 binding sites in the upstream promoter region. We show here that Gfi-1 represses CDKN1A in a manner that is independent of its DNA binding activity. Gfi-1 interacts with POZ-ZF transcription factor Miz-1, originally shown to be a c-Myc interacting partner, and via Miz-1 binds to CDKN1A core promoter. Interestingly, Gfi-1 and c-Myc, through Miz-1, form a ternary complex on the CDKN1A promoter, and act in collaboration to repress CDKN1A. Gfi-1 knockdown results in enhanced levels of p21^Cip1 and attenuated cell proliferation. Notably, similar to c-Myc, the expression of Gfi-1 is downregulated by TGFβ and the level of Gfi-1 influences the response of cell to the cytostatic effect of TGFβ. Our data reveal an important mechanism by which Gfi-1 regulates cell proliferation and may also have implications for understanding the role of Gfi-1 in lymphomagenesis.

A Design of a PET Detector Using Micro-Channel Plate Photomultipliers with Transmission-Line Readout

A computer simulation study has been conducted to investigate the feasibility of a positron emission tomography (PET) detector design by using micro-channel plate (MCP) photomultiplier tubes (PMT) with transmission-line (TL) read-out and waveform sampling. The detector unit consisted of a 24×24 array of pixelated LSO crystals, each of which was 4×4×25 mm(3) in size, and two 102×102 mm(2) MCP-PMTs coupled to both sides of the scintillator array. The crystal (and TL) pitch was 4.25 mm and reflective medium was inserted between the crystals. The transport of the optical photons inside the scintillator were simulated by using the Geant4 package. The output pulses of the MCP-PMT/TL unit were formed by applying the measured single photo-electron response of the MCP-PMT/TL unit to each individual photon that interacts with the photo-cathode of the MCP-PMT. The waveforms of the pulses at both ends of the TL strips were measured and analyzed to produce energy and timing information for the detected event. An experimental setup was developed by employing a Photonis Planacon MCP-PMT (XP85022) and a prototype TL board for measuring the single photo-electron response of the MCP-PMT/TL. The simulation was validated by comparing the predicted output pulses to measurements obtained with a single MCP-PMT/TL coupled to an LSO crystal exposed to 511 keV gamma rays. The validated simulation was then used to investigate the performance of the proposed new detector design. Our simulation result indicates an energy resolution of ~11% at 511 keV. When using a 400-600 keV energy window, we obtain a coincidence timing resolution of ~323 ps FWHM and a coincidence detection efficiency of ~40% for normally-incident 511keV photons. For the positioning accuracy, it is determined by the pitch of the TLs (and crystals) in the direction normal to the TLs and measured to be ~2.5 mm in the direction parallel to the TLs. The energy and timing obtained at the front- and back-end of the scintillator array also show differences that are correlated with the depth of interaction of the event.

Thalidomide has a therapeutic effect on interstitial lung fibrosis: evidence from in vitro and in vivo studies

The objective of this study was to investigate the effects of thalidomide (THD) on interstitial lung fibrosis (ILF). In vitro, human fetal lung fibroblast (HFL-F) to myofibroblast (MF) trans-differentiation was induced by transforming growth factor (TGF)-beta1. The effects of THD on trans-differentiation process or differentiated MF were evaluated by measuring hydroxyproline (HYP) content by alkaline hydrolysis colorimetry, alpha-smooth muscle actin (alpha-SMA) protein by Western blot and alpha-SMA and pro-collagen III mRNA expressions by semi-quantitative reverse transcription-polymerase chain reaction; in vivo, a mouse model of ILF was generated by daily subcutaneous injection of bleomycin (BLM) in female C3H mice. Gastric perfusion of THD began 1 week prior to injection and lasted for 8 weeks. Lung specimens were harvested at different time-points (1, 4, 6 and 8 weeks) for pathology and immunohistochemistry examination. The HYP content, alpha-SMA and pro-collagen III mRNA expressions were also assessed. THD inhibited the up-regulation of HYP protein, pro-collagen III mRNA and alpha-SMA protein induced by TGF-beta1 in HFL-F cells, and additionally inhibited pro-collagen III mRNA expression on trans-differentiated MF. THD reduced HYP synthesis in the lung tissues of BLM-treated mice at week 4, and slightly reduced the numbers of alpha-SMA-positive cells. THD had an effect on ILF models both in vitro and in vivo.

A Multi-Threshold Sampling Method for TOF PET Signal Processing

As an approach to realizing all-digital data acquisition for positron emission tomography (PET), we have previously proposed and studied a multi-threshold sampling method to generate samples of a PET event waveform with respect to a few user-defined amplitudes. In this sampling scheme, one can extract both the energy and timing information for an event. In this paper, we report our prototype implementation of this sampling method and the performance results obtained with this prototype. The prototype consists of two multi-threshold discriminator boards and a time-to-digital converter (TDC) board. Each of the multi-threshold discriminator boards takes one input and provides up to 8 threshold levels, which can be defined by users, for sampling the input signal. The TDC board employs the CERN HPTDC chip that determines the digitized times of the leading and falling edges of the discriminator output pulses. We connect our prototype electronics to the outputs of two Hamamatsu R9800 photomultiplier tubes (PMTs) that are individually coupled to a 6.25×6.25×25mm(3) LSO crystal. By analyzing waveform samples generated by using four thresholds, we obtain a coincidence timing resolution of about 340 ps and an ∼18% energy resolution at 511 keV. We are also able to estimate the decay-time constant from the resulting samples and obtain a mean value of 44ns with an ∼9 ns FWHM. In comparison, using digitized waveforms obtained at a 20 GSps sampling rate for the same LSO/PMT modules we obtain ∼300 ps coincidence timing resolution, ∼14% energy resolution at 511 keV, and ∼5 ns FWHM for the estimated decay-time constant. Details of the results on the timing and energy resolutions by using the multi-threshold method indicate that it is a promising approach for implementing digital PET data acquisition.

The role of P-glycoprotein/cellular prion protein interaction in multidrug-resistant breast cancer cells treated with paclitaxel

We previously reported that treatment with P-glycoprotein (P-gp) substrates promotes in vitro invasion in multidrug-resistant (MDR) breast cancer cells. This effect is initiated by the P-gp pump function and mediated by interaction of P-gp with some unknown component(s). However, the underlying mechanism(s) remains poorly understood. Here we confirm a novel physical interaction between P-gp and cellular prion protein (PrP(c)). Blocking P-gp activity or depletion of PrP(c) inhibited paclitaxel (P-gp substrate)- induced invasion. Paclitaxel further facilitated the formation of P-gp/PrP(c) clusters residing in caveolar domains and promoted the association of P-gp with caveolin-1. Both caveolin-1 and the integrity of caveolae were required for the drug-induced invasion. In addition, the P-gp/PrP(c) complex also played an important role in anti-apoptotic activity of MCF7/Adr cells.These data provide new insights into the mode by which MDR breast cancers evade cytotoxic attacks from P-gp substrates and also suggest a role for P-gp/ PrP(c) interaction in this process.

The Pd catalyst effect on low temperature hydrogen desorption from hydrided ultrathin Mg nanoblades

We present hydrogenation/de-hydrogenation properties of ultrathin Mg nanoblades coated with Pd as a catalyst. The hydrided Pd/Mg/Pd and Pd/Mg nanoblades were highly curved as observed by ex situ scanning electron microscopy. An in situ thermal desorption spectroscopy (TDS) study showed that the hydrided Pd/Mg/Pd nanostructure has a low hydrogen desorption temperature, at ∼365 K. Through a combinational microstructure and TDS analysis of hydrided Pd/Mg/Pd nanoblades as well as hydrided Pd/Mg/Pd nanoblades covered with an additional ultrathin Mg layer, we found that the effect of Pd catalyst on reducing the hydrogen desorption temperature is significantly stronger than the conventionally proposed mechanisms due to grain size and strain.