Oxytocin receptor expressed on the smooth muscle mediates the excitatory effect of oxytocin on gastric motility in rats

The aim of this study was to localize oxytocin receptor (OTR) in the stomach and to investigate the effect of OT on gastric motility in rats. Western blot and immunohistochemistry methods were used to localize OTR in stomach. The motility of stomach was recorded in vivo (recording of the intragastric pressure), in vitro (recording of the contraction of muscle strips) and on isolated smooth muscle cells. OTR was expressed on cells of both circular and longitudinal muscle of stomach. Systemic administration of OT induced an early transient decrease and a subsequent increase on intragastric pressure. Devazepide (1 mg kg(-1), i.v.), a cholecystokinin-1 (CCK(1)) receptor antagonist, completely abolished the transient response but did not influence the subsequent one. OT (10(-9)-10(-6) mol L(-1)) dose-dependently increased the contraction of the muscle strips of gastric body, antrum, and pyloric sphincter, and decreased the average cell length of isolated smooth muscle cells. Tetrodotoxin and atropine did not influence the effect of OT on muscle strips. Pretreatment with atosiban, an OTR antagonist, inhibited the spontaneous contraction of muscle strips and abolished the excitatory effect of OT on the muscle strips and the isolated cells. These results suggest that the OTR is expressed on the smooth muscle of the stomach and mediates excitatory effect of OT on gastric motility.

Phase 1b study of motesanib diphosphate (AMG 706) in combination with paclitaxel or docetaxel for the treatment of locally recurrent, unresectable or metastatic breast cancer

Abstract #4117

Background: Motesanib is a novel oral angiogenesis inhibitor designed to selectively target the tyrosine kinase activity of VEGF 1, 2 and 3; PDGF and Kit receptors. Here we report safety, preliminary efficacy and pharmacokinetics (PK) from an ongoing phase 1b dose-finding study of motesanib plus either paclitaxel (P) or docetaxel (D) in patients (pts) with advanced breast cancer.
 Methods: Eligible pts with ECOG 0 or 1 and ≤1 prior chemotherapy regimen for metastatic breast cancer received (until toxicity or disease progression) escalating doses of motesanib (50 or 125mg) QD orally continuously from day 3 of cycle 1 plus either P (Arm A) at 90mg/m2 on days 1, 8 and 15 of each 28-day cycle; or D (Arm B) at either 100mg/m2 on day 1 of every 21-day cycle or at 75mg/m2 with motesanib maximum tolerated dose (125mg QD). Objective response (OR) per RECIST was assessed every 8 (Arm A) or 6 wks (Arm B).
 Results: To date, 33 pts have received ≥1 dose of motesanib: Arm A, n=10; Arm B, n=23. Median age is 51 (range, 28-66) years. There were 5 DLTs (all grade 3) in 4 pts: abnormal liver function tests and deep vein thrombosis (Arm A, 125mg QD), fatigue (Arm A, 125mg QD), gallbladder enlargement (Arm B, 125mg QD+75mg/m2 D) and migraine (Arm B, 125mg QD). 28 pts (85%) had motesanib-related AEs; the most common were (worst grade): diarrhea, Arm A/B 60%/61% (grade 3, 0%/13%); fatigue, 30%/26% (grade 3, 10%/4%); hypertension, 20%/22% (grade 3, 10%/4%); and nausea, 10%/26% (no grade 3). Treatment-related AEs of interest in Arm A/B included epistaxis (10%/18%; all worst grade 1) and deep vein thrombosis (10%/0%; all worst grade 3). There were no grade 4 or 5 related AEs. Two deaths on study occurred (Arm B; 50 and 125mg QD n=1 each); both were not considered to be motesanib related. Motesanib PK parameters were generally within the range previously described for single-agent motesanib. PK profiles of P and D showed high interpatient variability, with AUC higher in some pts after motesanib coadministration. In pts with measurable disease at baseline (Arms A&B, n=7&18), best OR at time of last data cut-off was: confirmed PR in Arm A n=2 (29%), in Arm B n=5 (28%); SD in Arm A n=2 (29%), in Arm B n=9 (50%); durable SD ≥24 wks in Arm A n=0, in Arm B n=3 (17%). Median (range) duration of response currently is 169 (58-169) days in Arm A and 198 (96-337+) days in Arm B.
 Conclusions: Motesanib combined with P or D appears to be tolerable with evidence of antitumor activity in pts with advanced breast cancer. No marked effect on motesanib PK has been noted with coadministration of either P or D. Updated safety and efficacy data, including PFS, will be presented.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4117.

Are lifetime abstainers the best control group in alcohol epidemiology? On the stability and validity of reported lifetime abstention

Lifetime abstainers have often been recommended as the comparison group in alcohol epidemiology. The objective of this study was to provide insight into the validity and stability of lifetime abstention by using data derived from the National Alcohol Survey, a national probability survey of US households conducted in 1984, and its 2 follow-up surveys conducted in 1990 and 1992. Results indicated that more than half (52.9%; all proportions were weighted to represent the US population) of those who reported never having a drink of any alcoholic beverage in the 1992 survey reported drinking in previous surveys. Depending on assumptions, this difference may result in an underestimation of alcohol-attributable mortality of 2%-15% in men and 2%-22% in women. Sociodemographic factors differentiated those who consistently reported lifetime abstention across surveys from the rest of the study population. Results suggest that using reported lifetime abstainers as a sole comparison group is problematic, especially if reporting is based on 1 measurement only. Establishing multiple measurement points and including irregular lifetime light drinkers with lifetime abstainers as the comparison group are recommended for future epidemiologic studies.

Computational studies of the binding modes of A 2A adenosine receptor antagonists

A molecular docking study was performed on several structurally diverse A(2A) AR antagonists, including xanthines, and non-xanthine type antagonists to investigate their binding modes with A(2A) adenosine receptor (AR), one of the four subtypes of AR, which is currently of great interest as a target for therapeutic intervention, in particular for Parkinson's disease. The high-affinity binding site was found to be a hydrophobic pocket with the involvement of hydrogen bonding interactions as well as pi-pi stacking interactions with the ligands. The detailed binding modes for both xanthine and non-xanthine type A(2A) antagonists were compared and the essential features were extracted and converted to database searchable queries for virtual screening study of novel A(2A) AR antagonists. Findings from this study are helpful for elucidating the binding pattern of A(2A) AR antagonists and for the design of novel active ligands.

Polyubiquitin chains: functions, structures, and mechanisms

Ubiquitin is a highly conserved 76-amino acid polypeptide that is found throughout the eukaryotic kingdom. The covalent conjugation of ubiquitin (often in the form of a polymer) to substrates governs a variety of biological processes ranging from proteolysis to DNA damage tolerance. The functional flexibility of this post-translational modification has its roots in the existence of a large number of ubiquitinating enzymes that catalyze the formation of distinct ubiquitin polymers, which in turn encode different signals. This review summarizes recent advances in the field with an emphasis on the non-canonical functions of polyubiquitination. We also discuss the potential mechanism of chain linkage specification as well as how structural disparity in ubiquitin polymers may be distinguished by ubiquitin receptors to translate the versatile ubiquitin signals into various cellular functions.

Transcriptional differences between the male-sterile mutant bcms and wild-type Brassica campestris ssp. chinensis reveal genes related to pollen development

A novel male-sterile mutant which lacks mature pollen, Brassisa campestris male sterile (bcms), was identified in Brassica campestris L. ssp. chinensis Makino (syn. B. rapa ssp. chinensis). Genetic analysis revealed that bcms was controlled by a single recessive mutation locus. Genome-wide transcriptional profiling was performed on the flower buds of both the bcms mutant and the wild-type from which it originated, and profiling analysis indicated that there were numerous changes in gene expression attributable to the gene mutation. This mutation resulted in down-regulation of a variety of genes and up-regulated expression of a few other genes. A total of 51 transcript-derived fragments (TDFs) were isolated: 32 specifically and 12 predominantly accumulated in wild-type flower buds, and two specifically and five predominantly accumulated in bcms flower buds. Sequence analysis showed that some of these TDFs share significant similarities with genes involved in different aspects of cellular development, such as signal transduction, cell wall biosynthesis and regulation. Most other TDFs showed no or very poor sequence similarities to entries in any database and might represent new candidate proteins involved in pollen development. Furthermore, spatial and temporal expression pattern analysis of 20 genes derived from cDNA-amplified fragment length polymorphism in different tissues of both the bcms and wild-type plants revealed their complex and dynamic expression patterns. The bcms mutant and the genes isolated in this paper provide excellent material for future studies on the molecular mechanism of male sterility.

Combined method for artifact reduction in surface electroenterogram

Surface electroenterogram (EEnG) is a non-invasive method for monitoring the intestinal motility. However, surface EEnG recordings are contaminated by movement artifact, cardiac activity, respiratory artifact and other interferences. The aim of this work is to remove movement artifacts by means of a combined method of empirical mode decomposition (EMD) and independent component analysis (ICA). Four recording sessions were conducted on canine model. Surface signals from 4 different channels are decomposed using EMD. Resulting intrinsic mode functions are the inputs of ICA analysis which permits to separate and identify the activities of different origin. Signal components associated to movement artifacts are removed and the original signals are reconstructed by means of an inverse procedure. The results show that the proposed method allows extracting and cancelling movement artifacts from surface EEnG, avoiding the presence of irregular peaks in external intestinal motility indexes. Therefore, the proposed method could be useful to reduce artifacts in EEnG recording and to provide more robust non-invasive intestinal motility indicators.

Cell death in mammalian development

During embryogenesis there is an exquisite orchestration of cellular division, movement, differentiation, and death. Cell death is one of the most important aspects of organization of the developing embryo, as alteration in timing, level, or pattern of cell death can lead to developmental anomalies. Cell death shapes the embryo and defines the eventual functions of the organs. Cells die using different paths; understanding which path a dying cell takes helps us define the signals that regulate the fate of the cell. Our understanding of cell death in development stems from a number of observations indicating genetic regulation of the death process. With today's increased knowledge of the pathways of cell death and the identification of the genes whose products regulate the pathways we know that, although elimination of some of these gene products has no developmental phenotype, alteration of several others has profound effects. In this review we discuss the types and distributions of cell death seen in developing mammalian embryos as well as the gene products that may regulate the process.

Quantification of combined method for interferences reduction in multichannel surface electroenterogram

Surface electroenterogram (EEnG) is a non-invasive method for monitoring the intestinal motility. However, surface EEnG signals are contaminated by strong physiological interferences. The main interferences which affect high-frequency components of surface EEnG are cardiac activity and movement artifacts. The aim of this work is to quantify the effectiveness of a combined method based on empirical mode decomposition and independent component analysis to remove these interferences from multichannel surface EEnG. In order to do so, several parameters were calculated from five recording sessions: Signal-to-ECG interference ratio (S/I) and variation of energy over 2 Hz (EF2). The results show that the S/I of processed signals was significantly higher than that of original signals, moreover the improvement of the S/I ratio is due to the attenuation of energy associated to interference. The proposed method also allows cancelling movement artifacts from surface EEnG, reducing considerably the non-physiological variation of EF2. Furthermore after the application of the combined method, correlation coefficient between EF2 of internal recording with EF2 of surface recording is greatly higher. Therefore, the proposed method could be helpful to reduce high-frequency interferences in EEnG recording and to provide more robust non-invasive intestinal motility indicators.

High resolution spectroscopy of (lambda)(12)B by electroproduction

An experiment measuring electroproduction of hypernuclei has been performed in hall A at Jefferson Lab on a 12C target. In order to increase counting rates and provide unambiguous kaon identification two superconducting septum magnets and a ring imaging Cherenkov detector were added to the hall A standard equipment. An unprecedented energy resolution of less than 700 keV FWHM has been achieved. Thus, the observed (Lambda)(12)B spectrum shows for the first time identifiable strength in the core-excited region between the ground-state s-wave Lambda peak and the 11 MeV p-wave Lambda peak.

The study of the relationship between Notch signal transduction pathway and polycomb protein Bmi1 in colorectal caner cells

14501

Background: As is known the polycomb group protein BMI1 has been shown to support normal stem cell proliferation via its putative stem cell factor function. However, the potential molecular mechanism of BMI1 act as a cancer stem cell factor may also promote cancer development is unclear. In this study we demonstrated for the first time that Notch signal transduction pathway regulating expression of Bmi1 in colorecta caner cells and investigate the Notch1 mRNA and Bmi1 mRNA level in human colorectal cancer samples and their correlation with clinicopathological parameters of colorectal cancer. Methods and Results: We assessed Notch1 and Bmi1 mRNA in 50 cases of colorectal cancer and adjacent normal tissue by RT-PCR. The immunohistochemistry was used to determine the expression of ICN and in the 50 tissues of colorectal cancer and normal mucosa. Bmi1 SW480 cells were treated with DAPT (g-secretase inhibitor) at different times. MTT assay and flow cytometry were used to measure the proliferation and apoptosis of SW480 cells. The expression of ICN, Bmi1 were measured by western blot. Notch1 and Bmi1 mRNA level were increased in colorectal cancer compared with adjacent normal mucosa (P<0.05), the median values were 1.97-fold, 1.88-fold, respectively. It was found that overexpression of Notch1 and Bmi1 was related to differentiation and lymph nodes metastasis in colorectal cancer (P<0.05). The correlation between Notch1 and Bmi1 mRNA level, ICN and Bmi1 protein level are significant at the 0.01 level. Treating SW480 with DAPT, resulted in significant growth inhibition, apoptosis induction and downregulation of ICN and Bmi1. Conclusion: Our results show that overexpression of Notch1 and Bmi1 may play a critical role in the development of colorectal cancer. Notch1 signal transduction pathway regulating expression of Bmi1 in colorectal cancer cells.Blockade of Notch1 signal pathway can inhibit proliferation and accelerate apoptosis of colorectal cancer. [Key words] Colorectal cancer; BMI1; Signal transducers and activators of transcription3; Western blotting

No significant financial relationships to disclose.

Empirical mode decomposition: a method to reduce low frequency interferences from surface electroenterogram

The surface electroenterogram (EEnG) is a non-invasive method of studying myoelectrical bowel activity. However, surface EEnG recordings are contaminated by cardiac activity, respiratory and motion artifacts, and other sources of interference. The aim of this work is to remove the respiration artifact and the very low frequency components from surface EEnG by means of empirical mode decomposition (EMD). Eleven recording sessions were carried out on canine model. Several parameters were calculated before and after the application of the method: signal-to-interference ratio (S/I ratio) and the attenuation level of the signal and of interference. The results show that the S/I ratio was significantly higher after the application of the method (3.68+/-5.54 dB vs. 10.45+/-3.65 dB), the attenuation level of signal and of interference is -0.49+/-0.80 dB versus -7.26+/-5.42 dB, respectively. Therefore, EMD could be a useful aid in identifying the intestinal slow wave and in removing interferences from EEnG recordings.