VS-105: a novel vitamin D receptor modulator with cardiovascular protective effects

BACKGROUND AND PURPOSE

Vitamin D receptor (VDR) modulators (VDRMs) such as calcitriol, paricalcitol and doxercalciferol are commonly used to manage hyperparathyroidism secondary to chronic kidney disease (CKD). CKD patients experience extremely high risks of cardiovascular morbidity and mortality. Clinical observations show that VDRM therapy may be associated with cardio-renal protective and survival benefits for CKD patients. However, hypercalcaemia remains a serious side effect for current VDRMs, which leads to the need for frequent dose titration and serum Ca (calcium) monitoring. Significant clinical benefits can be derived from a VDRM with cardiovascular protective effects without the hypercalcaemic liability.

EXPERIMENTAL APPROACH

Male Sprague-Dawley rats were 5/6 nephrectomized and 6 weeks later, after they had established uraemia, elevated parathyroid hormone levels, endothelial dysfunction and left ventricular hypertrophy, the rats were treated with VS-105, a novel VDRM. The effects of VS-105 were also tested in cultured HL-60 cells.

KEY RESULTS

VS-105 induced HL-60 cell differentiation with an EC₅₀ value at 11.8 nM. Treatment (i.p., 3× a week over a period of 2 weeks) of the 5/6 nephrectomized rats by VS-105 (0.004-0.64 µg·kg⁻¹) effectively suppressed serum parathyroid hormone without raising serum Ca or phosphate levels. Furthermore, 2 weeks of treatment with VS-105 improved endothelium-dependent aortic relaxation and attenuated left ventricular abnormalities in a dose range that did not affect serum Ca levels. Similar results were obtained when VS-105 was administered i.p. or by oral gavage.

CONCLUSIONS AND IMPLICATIONS

VS-105 exhibits an overall therapeutic product profile that supports expanded use in CKD to realize the cardiovascular protective effects of VDR activation.

Endoscopic pyloromyotomy: a new concept of minimally invasive surgery for pyloric stenosis

BACKGROUND AND STUDY AIMS

Pyloric stenosis is currently managed using open or laparoscopic pyloromyotomy. However, with recent improvements in flexible endoscopic instrumentation and techniques, totally peroral endoscopic approaches could reduce the invasiveness of myotomic procedures. The aim of the study was to establish the feasibility and efficacy of endoscopic submucosal pyloromyotomy in a porcine model.

METHODS

Four pigs were included in a preliminary study and a 2-week survival study was performed in another four pigs. An esophagogastroduodenoscope was inserted perorally into the stomach. Saline solution was injected into the submucosal space proximal to the pylorus. The gastric mucosa was incised and a 5-cm submucosal tunnel was created. After exposure of the muscular layer in a submucosal tunnel, myotomy of the circular muscle layer was performed until the longitudinal muscular layer was reached. Once myotomy was completed, endoscopic clips were used to re-approximate the mucosal incision.

RESULTS

Submucosal dissection, identification of the circular muscular layer, and pyloromyotomy were achieved in all animals. Acute complications such as bleeding and perforation were not observed in any cases. Median pyloric resting pressure was reduced from 16.5 mmHg to 6.1 mmHg immediately after myotomy and 8.4 mmHg at 14 days after myotomy.

CONCLUSION

Peroral endoscopic submucosal pyloromyotomy appears to be technically feasible and effective. Potential clinical applications, such as for infantile hypertrophic pyloric stenosis or delayed gastric emptying after esophagectomy, could be considered after confirmation of safety in additional survival studies.

P5-13-02: Prediction of Dasatinib Sensitivity of Breast Cancer Based on a Novel Tyrosine Kinase-Activity Profiling Assay

Background: Receptor tyrosine kinases and other membrane-associated tyrosine kinases are frequently overexpressed, activated, or mutated in cancer cells and cause aberrant signal transduction, which leads to cellular proliferation, angiogenesis, metastasis, and antiapoptosis. Blockage of these signals is considered an efficient strategy in cancer therapy, and to date, several tyrosine kinase inhibitors (TKIs) and antibody drugs targeting such kinases have been developed and are routinely used in clinics. However, the efficacy rates of the drugs are, unfortunately, limited. To provide optimum care for individual patients, an accurate prediction method for drug efficacy is now strongly demanded. Recent studies have shown that alteration of multiple kinases is involved in both primary and acquired drug resistance. Advantages of multi-targeted TKIs have also been reported. These findings indicate the need for a comprehensive evaluation of multiple kinases for predicting drug response. To achieve this, we developed a novel method of comprehensively profiling kinase activity.

Materials and methods: We characterized the membranous tyrosine kinases of breast cancer cell lines using a newly established profiling assay. Briefly, crude membrane fractions were prepared and directly subjected to the assay with nonspecific substrate (Poly(Glu4-Tyr)). The profile of the kinases in the crude membrane fraction was obtained by inhibiting the total activity with 13 selected kinds of adenosine triphosphate antagonists, independently. The residual activity (RA) of membranous kinases was defined as the percentage of activity with/without TKI.

Results: Nineteen breast cancer cell lines were classified as “sensitive” (n = 6) and “resistant” (n = 13) to dasatinib according to the definition in the publication (Cancer Res., 67 2226–38. 2007). The RA of tyrosine kinases targeted by different types of TKIs was determined by our assay, and we found that two RAs (src inhibitor 1 and PP1) showed statistically significant differences between the “sensitive” and “resistant” groups (p=0.017, and p=0.002, respectively, Student's t-test). The RA of the two TKIs were also significant predictors for dasatinib sensitivity in a receiver operating characteristic curve analysis (area under the curve: 0.846 for src inhibitor 1 and 0.910 for PP1). Since the major target of dasatinib are src family kinases, protein expressions of the src family of the cell lines were quantified by a Western blotting and compared between the groups. We found that the protein expression is not a statistically significant predictor of dasatinib sensitivity.

Conclusion: We have shown that a comprehensive tyrosine kinase activity profiling assay of cancer cells can predict dasatinib sensitivity. We plan to validate this assay prospectively in patients with breast cancer who receive dasatinib.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-13-02.

Relationships between myonuclear domain size and fibre properties in the muscles of Thoroughbred horses

REASONS FOR PERFORMING STUDY

The myonuclear domain (MND) is the region of cytoplasm governed by a single myonucleus. Myonuclear domain size is an important factor for muscle fibre plasticity because each myonucleus has limitations in the capacity of protein synthesis. Previous studies have demonstrated that differences in MND size exist in different fibre types in several species, including horses.

OBJECTIVES

To understand the basic mechanism of muscle plasticity, the relationships between MND size, muscle fibre type population and metabolic properties of skeletal muscles throughout the whole body in Thoroughbred horses were examined.

METHODS

Post mortem samples were taken from 20 muscles in 3 Thoroughbred horses aged 3-5 years of age. Fibre type population was determined on serial cross sections of each muscle sample, stained for monoclonal antibodies to each myosin heavy chain isoform. Oxidative (succinic dehydrogenase; SDH) and glycolytic (phosphofructokinase; PFK) enzyme activities were determined spectrophotometrically in each muscle sample. Furthermore, 30 single fibres were isolated from each muscle under stereomicroscopy and then fibre volume and myonuclear number for a given length analysed under confocal microscopy. The MND size of each single fibre was measured after normalisation of sarcomere length to 2.8 µm by staining with membrane-specific dye.

RESULTS

Immunohistochemical staining indicated that soleus, vastus lateralis and gluteus medius muscles had the highest percentage of type I, IIa and IIx muscle fibre, respectively. Biochemical analysis indicated highest activities of SDH and PFK in diaphragm and longissimus lumborum muscles, respectively. MNDs were largest in the splenius muscle and smallest in the soleus and masseter muscles. Myonuclear domain size is significantly related to type I muscle fibre population, but not to SDH activities of the muscles.

CONCLUSION

The MND size of muscle fibre depends on fibre type population rather than mitochondrial enzyme activities.

Control of molecular rotors by selection of anchoring sites

We demonstrate a new method to switch on and off the rotational motion of a long-chain molecule by controlling the bonding geometry between the molecule and a substrate. An azobenzene derivative molecule adsorbed on a Au(111) surface is immobile only when its three rotation centers, comprised of two phenyl rings and a nitrogen-nitrogen bond, are located at hollow sites of the Au(111) surface, as observed by scanning tunneling microscopy. Rotational motion can be activated by exciting the vibrational modes and inducing hopping motion away from the immobile site with a voltage pulse.

Range of motion exercise of temporo-mandibular joint with hot pack increases occlusal force in patients with Duchenne muscular dystrophy

The purpose of this study is to evaluate whether the range of motion exercise of the temporo-mandibular joint (jaw ROM exercise) with a hot pack and massage of the masseter muscle improve biting disorder in Duchenne muscular dystrophy (DMD). The subjects were 18 DMD patients (21.3+/- 4.1 years old). The jaw ROM exercise consisted of therapist-assisted training (2 times a week) and self-training (before each meal every day). The therapist-assisted training consisted of the application of a hot pack on the cheek of the masseter muscle region (15 minutes), the massage of the masseter (10 minutes), and jaw ROM exercise (5 minutes). The self-training involved jaw ROM exercise by opening the mouth to the maximum degree, ten times. These trainings continued for six months. Outcomes were evaluated by measuring the greatest occlusal force and the distance at the maximum degree of mouth opening between an incisor of the top and that of the bottom. Six months later, the greatest occlusal force had increased significantly compared with that at the start of jaw ROM exercise (intermediate values: from 73.8N to 97.3N) (p = 0.005) as determined by the Friedman test and Scheffi's nonparametric test. The patients' satisfaction with meals increased. However, the maximum degree of mouth opening did not change after six months of jaw ROM exercise. Jaw ROM exercise in DMD is effective for increasing the greatest occlusal force.

Fully laparoscopic colorectal anastomosis involving percutaneous endoluminal colonic anvil control (PECAC)

INTRODUCTION

A novel technique for secure placement of the anvil for mechanical stapled anastomosis in the proximal colon without exteriorization of the bowel is described.

METHODS

After standard laparoscopic segmental colonic mobilization, a needle-cannula from a percutaneous endoscopic gastrostomy kit is passed under direct endoscopic vision transparietally into the colon at the site intended for anvil placement. A wire passed through the cannula into the colon is then withdrawn endoscopically per ano. The stapler anvil is fixed to the wire and pulled back along the intestine before being positioned by traction through the needle puncture site. After distal specimen transection, a standard stapled anastomosis is performed.

RESULTS

The technique is illustrated in 2 patients undergoing laparoscopic sigmoidectomy by either a single port or a multiport procedure with transanal specimen extraction.

CONCLUSION

By positioning the anvil without colon exteriorization, this technique enables pure intraperitoneal colonic anastomoses that may advance natural orifice operating.

Adiposity, adult weight change and breast cancer risk in postmenopausal Japanese women: the Miyagi Cohort Study

Background:

The role of adult weight change in breast cancer (BC) risk is unclear in Japanese women.

Methods:

A total of 10 106 postmenopausal women aged 40–64 years (the Miyagi Cohort) were followed from 1990 to 2003, and 108 BC cases were identified. Hazard ratios (HRs) were estimated according to body mass index (BMI) at the current age and at the of age 20 years, and weight change since age 20 years.

Results:

Higher current BMI was associated with an increased risk of BC (P for trend=0.02), whereas higher BMI at the age 20 years was inversely associated with this risk (P for trend=0.002). There was a significant association between weight change since age 20 years and BC risk (P for trend=0.0086). Compared with stable weight, HR was 0.35 for weight loss of 5 kg or more (P for weight loss trend=0.04) and 1.55 for weight gain of 12 kg or more (P for weight gain trend=0.05).

Conclusion:

Adiposity at younger and current age has differential effects on BC risk among postmenopausal women; weight gain in adulthood being associated with an increased, and weight loss with a decreased risk.

Fluorescence detection of atmospheric nitrogen dioxide using a blue light-emitting diode as an excitation source

We report on the development of a low-cost and compact instrument for quantifying atmospheric NO(2) concentrations by detecting NO(2) fluorescence using a commercial light-emitting diode around 435 nm as a fluorescence excitation light source. The minimum detectable limit of the NO(2) instrument developed has been estimated to be 9.8 parts per billion of volume mixing ratio (ppbv) in a 60 s integration time and with a signal-to-noise ratio of 2.

A selective, high affinity 5-HT 2B receptor antagonist inhibits visceral hypersensitivity in rats

BACKGROUND

RS-127445 is a selective, high affinity 5-HT(2B)receptor antagonist. We investigated whether 5-HT(2B)receptor antagonists can reduce colonic visceral hypersensitivity caused by restraint stress or by proximal colonic inflammation.

METHODS

Visceral hypersensitivity was induced in rats by either restraint stress or injection of 2, 4, 6-trinitrobenzene sulfonic acid (TNBS) into the proximal colon. Restraint stress produced a significant increase in numbers of abdominal contractions evoked by colorectal distension (CRD), measured as a quantitative index of visceral nociception in rats. Seven days after TNBS injection, the pain threshold to CRD at the non-inflamed distal colon, that was determined as the minimum pressure required to evoke abdominal cramp, was significantly decreased. The effect of RS-127445 on visceral hypersensitivity was assessed in either naïve or TNBS-treated rats.

KEY RESULTS

Oral administration of a selective, high affinity 5-HT(2B)receptor antagonist, RS-127445, significantly inhibited visceral hypersensitivity provoked by restraint stress (35 to 74% inhibition at 1 to 10 mg kg(-1)). Oral RS-127445 produced a significant suppression of TNBS-induced visceral hypersensitivity (15 to 62% inhibition at 3 to 30 mg kg(-1)), although it was without significant effect on the visceral nociceptive threshold of naïve rats. RS-127445 (1 to 30 mg kg(-1), p.o.) also dose-dependently reduced the restraint stress-induced defecation in naïve and TNBS-treated rats.

CONCLUSIONS & INFERENCES

These results suggest that 5-HT(2B)receptors are involved in signaling from the colon in rats in which there is visceral hypersensitivity and that a selective 5-HT(2B)receptor antagonist could have therapeutic potential for the treatment of gut disorders characterized by visceral hypersensitivity.

Antimicrobial activity of the extracts and physalin D from Physalis alkekengi and evaluation of antioxidant potential of physalin D

Physalis alkekengi L. (Solanaceae) is a popular plant in traditional European and Chinese folk medicine, and it has been reported to have many ethnopharmacological properties including antifungal, anti-cough, anti-inflammatory, analgesic, and febricide activities. Some active components from Physalis species have been investigated. However, no antimicrobial activity studies on extracts and physalins of P. alkekengi have been carried out. In this study, we attempted to identify the possible antimicrobial activities of the methanol extract from aerial parts of P. alkekengi and the dichloromethane extract from calyces of the plant. The extracts were tested against five Gram-positive and five Gram-negative bacteria and five Candida species by using disk diffusion and broth microdilution methods. The extracts were fractionated to isolate physalins using chromatographic techniques, and physalin D was isolated from the extracts. The structure of the compound was elucidated on the basis of (1)H-NMR spectroscopic study, and confirmed by comparison with a reference sample and literature data. Results indicated that all the extracts and physalin D were characterized by antibacterial action, especially against Gram-positive bacteria, with MIC values between 32 and 128 microg/mL. The methanol extract had moderate activity against fungi at MICs ranging from 128 to 512 microg/mL, but the dichloromethane extract and physalin D had low activity against fungi at MICs ranging from 256 to 512 microg/mL. Additionally, the antioxidant activity of physalin D was evaluated by qualitative DPPH (1,1-diphenyl-2-picrylhydrazyl) radical and TBA (thiobarbituric acid) assays. Physalin D showed low antioxidant activity with an IC(50) value of >or= 10 +/- 2.1.

Local analysis of the edge dislocation core in BaTiO(3) thin film by STEM-EELS

The a <100> edge dislocation core formed in an epitaxial BaTiO(3) (BTO) thin film grown on a substrate was investigated by scanning transmission electron microscopy combined with electron energy-loss spectroscopy. Elemental analysis using core-loss spectrum indicates that the atomic ratios of O/Ti and Ba/Ti are decreased at the dislocation core. The near-edge fine structure of the oxygen K-edge recorded from the dislocation core differs slightly from that of relaxed BTO region, which suggests that Ba-O bonding is decreased at the dislocation core. The structure of the dislocation core is discussed using a high-angle annular dark-field image and the electron energy-loss spectroscopy results.