Effective in vitro evaluation of the risk of histamine release related to valemetostat tosylate using MRGPRX2-expressing cells

Mas-related G-protein-coupled receptor X2 (MRGPRX2), expressed on mast cells, is associated with drug-induced pseudo-allergic reactions. Although it is well known that there are differences of sensitivity between species in the pseudo-allergic reactions, no platform for evaluating a human risk of the pseudo-allergic reactions observed in nonclinical studies has been established. Valemetostat tosylate, developed as an anti-cancer drug, induced histamine release in a nonclinical study with dogs. The purpose of the current study was to identify the mechanism and assess the human risk of valemetostat-tosylate-induced histamine release using dog and human MRGPRX2-expressing cells. In an experiment with human or dog MRGPRX2-expressing cells, valemetostat tosylate caused activation of human and dog MRGPRX2. Importantly, the EC50 for dog MRGPRX2 was consistent with the Cmax value at which histamine release was observed in dogs. Furthermore, the EC50 for human MRGPRX2 was ca. 27-fold higher than that for dog MRGPRX2, indicating a species difference in histamine-releasing activity. In a clinical trial, histamine release was not observed in patients receiving valemetostat tosylate. In conclusion, an in vitro assay using human and animal MRGPRX2-expressing cells would be an effective platform to investigate the mechanism and predict the human risk of histamine release observed in nonclinical studies.

Outer retinal involvement in N-methyl-D-aspartate-induced inner retinal injury in rabbits assessed by optical coherence tomography

This study was aimed to investigate morphological alteration of the retina with N-methyl-D-aspartate (NMDA)-induced injury in rabbits by optical coherence tomography (OCT). The right and left eyes of a total of 12 rabbits received single-intravitreal injection of vehicle and NMDA, respectively. Four out of the 12 animals underwent OCT and quantification of plasma microRNA repeatedly (4, 48, and 168 hr after dosing), followed by ocular histopathology at the end of the study. Ocular histopathology was also conducted in the eyes collected 4 or 48 hr after dosing from 4 animals at each time period. OCT revealed hyper-reflective ganglion cell complex and thickened inner retina in NMDA-treated eyes 4 hr after dosing; the inner retina shifted to thinning at later time points. The eyes given NMDA also exhibited greater thickness of the outer retina, which contains photoreceptors, after treatment, and thickened and obscured ellipsoid zone 168 hr after dosing. The plasma levels of miR-182 and miR-183, which are known to be highly expressed in photoreceptors, were higher 4 hr after dosing than pre-dosing values. Histopathologically, NMDA-induced inner retinal damage was confirmed: single-cell necrosis was observed in the ganglion cell layer and the inner nuclear layer 4 hr after dosing, the incidence of which decreased thereafter. At 168 hr after dosing, reduced number of ganglion cells was noted. No change was histopathologically observed in the outer retina. In conclusion, our results suggest involvement of photoreceptors in NMDA-induced inner retinal injury. Additionally, OCT revealed acute inner retinal findings suggestive of temporary edema.

Mouse models of X-linked juvenile retinoschisis have an early onset phenotype, the severity of which varies with genotype

X-linked juvenile retinoschisis (XLRS) is an early-onset inherited condition that affects primarily males and is characterized by cystic lesions of the inner retina, decreased visual acuity and contrast sensitivity and a selective reduction of the electroretinogram (ERG) b-wave. Although XLRS is genetically heterogeneous, all mouse models developed to date involve engineered or spontaneous null mutations. In the present study, we have studied three new Rs1 mutant mouse models: (1) a knockout with inserted lacZ reporter gene; (2) a C59S point mutant substitution and (3) an R141C point mutant substitution. Mice were studied from postnatal day (P15) to 28 weeks by spectral domain optical coherence tomography and ERG. Retinas of P21-22 mice were examined using biochemistry, single cell electrophysiology of retinal ganglion cells (RGCs) and by immunohistochemistry. Each model developed intraretinal schisis and reductions in the ERG that were greater for the b-wave than the a-wave. The phenotype of the C59S mutant appeared less severe than the other mutants by ERG at adult ages. RGC electrophysiology demonstrated elevated activity in the absence of a visual stimulus and reduced signal-to-noise ratios in response to light stimuli. Immunohistochemical analysis documented early abnormalities in all cells of the outer retina. Together, these results provide significant insight into the early events of XLRS pathophysiology, from phenotype differences between disease-causing variants to common mechanistic events that may play critical roles in disease presentation and progression.

Role of monocarboxylate transporters in regulating metabolic homeostasis in the outer retina: Insight gained from cell-specific Bsg deletion

The neural retina metabolizes glucose through aerobic glycolysis generating large amounts of lactate. Lactate flux into and out of cells is regulated by proton-coupled monocarboxylate transporters (MCTs), which are encoded by members of the Slc16a family. MCT1, MCT3, and MCT4 are expressed in the retina and require association with the accessory protein basigin, encoded by Bsg, for maturation and trafficking to the plasma membrane. Bsg^-/- mice have severely reduced electroretinograms (ERGs) and progressive photoreceptor degeneration, which is presumed to be driven by metabolic dysfunction resulting from loss of MCTs. To understand the basis of the Bsg^-/- phenotype, we generated mice with conditional deletion of Bsg in rods (RodΔBsg), cones (Cone∆Bsg), or retinal pigment epithelial cells (RPEΔBsg). RodΔBsg mice showed a progressive loss of photoreceptors, while ConeΔBsg mice did not display a degenerative phenotype. The RPEΔBsg mice developed a distinct phenotype characterized by severely reduced ERG responses as early as 4 weeks of age. The loss of lactate transporters from the RPE most closely resembled the phenotype of the Bsg^-/- mouse, suggesting that the regulation of lactate levels in the RPE and the subretinal space is essential for the viability and function of photoreceptors.

Reduced expression of the nob8 gene does not normalize the distribution or function of mGluR6 in the mouse retina

Purpose

The Grm6nob8 mouse carries a missense mutation in the Grm6 gene (p.Met66Leu), and exhibits a reduced b-wave of the electroretinogram (ERG), abnormal localization of metabotropic glutamate receptor 6 (mGluR6) to the depolarizing bipolar cell (DBC) soma, and a reduced level of mGluR6 at the DBC dendritic tips. Although the underlying mechanism remains unknown, one possible explanation is that DBCs cannot efficiently traffic the mutant mGluR6. In that scenario, reducing the total amount of mutant mGluR6 protein might normalize localization, and thus, improve the ERG phenotype as well. The second purpose of this study was to determine whether the abnormal cellular distribution of mutant mGluR6 in Grm6nob8 retinas might induce late onset DBC degeneration.

Methods

We crossed Grm6nob8 animals with Grm6nob3 mice, which carry a null mutation in Grm6, to generate Grm6nob3/nob8 compound heterozygotes. We used western blotting to measure the total mGluR6 content, and immunohistochemistry to document mGluR6 localization within DBCs. In addition, we examined outer retinal function with ERG and retinal architecture in vivo with spectral domain optical coherence tomography (SD-OCT).

Results

The retinal content of mGluR6 was reduced in the retinas of the Grm6nob3/nob8 compound heterozygotes compared to the Grm6nob8 homozygotes. The cellular distribution of mGluR6 in the Grm6nob3/nob8 compound heterozygotes matched that of the Grm6nob8 homozygotes, with extensive expression throughout the DBC cell body and limited expression at the DBC dendritic tips. The dark-adapted ERG b-waves of the Grm6nob3/nob8 mice were reduced in comparison to those of the Grm6nob8 homozygotes at postnatal day 21 and 28. The overall ERG waveforms obtained from 4- through 68-week old Grm6nob8 mice were in general agreement for dark- and light-adapted conditions. The maximum response and sensitivity of the dark-adapted ERG b-wave did not change statistically significantly with age. SD-OCT revealed the maintained laminar structure of the retina, including a clear inner nuclear layer (INL) at each age examined (from 11 to 57 weeks old), although the INL in the mice older than 39 weeks of age was somewhat thinner than that seen at 11 weeks.

Conclusions

Mislocalization of mutant mGluR6 is not normalized by reducing the total mGluR6. Mislocalized mutant mGluR6 does not trigger substantial loss of DBCs.

Noninvasive Electroretinographic Procedures for the Study of the Mouse Retina

Overall retinal function can be monitored by recording the light-evoked response of the eye at the corneal surface. The major components of the electroretinogram (ERG) provide important information regarding the functional status of many retinal cell types including rod photoreceptors, cone photoreceptors, bipolar cells, and the retinal pigment epithelium (RPE). The ERG can be readily recorded from mice, and this unit describes procedures for mouse anesthesia and the use of stimulation and recording procedures for measuring ERGs that reflect the response properties of different retinal cell types. Through these, the mouse ERG provides a noninvasive approach to measure multiple aspects of outer retinal function, including the status of the initial rod and cone pathways, rod photoreceptor deactivation, rod dark adaptation, the photoreceptor-to-bipolar cell synapse, and the RPE. © 2018 by John Wiley & Sons, Inc.

Retinoid isomerase inhibitors impair but do not block mammalian cone photoreceptor function

RPE65 is a retinoid isomerase essential for rod function, but its contribution to cone vision is enigmatic. Using selective RPE65 inhibitors, Kiser et al. demonstrate that cone function depends only partially on continuous RPE65 activity, providing support for cone-specific regeneration mechanisms.

Visual function in vertebrates critically depends on the continuous regeneration of visual pigments in rod and cone photoreceptors. RPE65 is a well-established retinoid isomerase in the pigment epithelium that regenerates rhodopsin during the rod visual cycle; however, its contribution to the regeneration of cone pigments remains obscure. In this study, we use potent and selective RPE65 inhibitors in rod- and cone-dominant animal models to discern the role of this enzyme in cone-mediated vision. We confirm that retinylamine and emixustat-family compounds selectively inhibit RPE65 over DES1, the putative retinoid isomerase of the intraretinal visual cycle. In vivo and ex vivo electroretinography experiments in Gnat1^−/− mice demonstrate that acute administration of RPE65 inhibitors after a bleach suppresses the late, slow phase of cone dark adaptation without affecting the initial rapid portion, which reflects intraretinal visual cycle function. Acute administration of these compounds does not affect the light sensitivity of cone photoreceptors in mice during extended exposure to background light, but does slow all phases of subsequent dark recovery. We also show that cone function is only partially suppressed in cone-dominant ground squirrels and wild-type mice by multiday administration of an RPE65 inhibitor despite profound blockade of RPE65 activity. Complementary experiments in these animal models using the DES1 inhibitor fenretinide show more modest effects on cone recovery. Collectively, these studies demonstrate a role for continuous RPE65 activity in mammalian cone pigment regeneration and provide further evidence for RPE65-independent regeneration mechanisms.

Novel orally bioavailable EZH1/2 dual inhibitors with greater antitumor efficacy than an EZH2 selective inhibitor

Polycomb repressive complex 2 (PRC2) methylates histone H3 lysine 27 and represses gene expression to regulate cell proliferation and differentiation. Enhancer of zeste homolog 2 (EZH2) or its close homolog EZH1 functions as a catalytic subunit of PRC2, so there are two PRC2 complexes containing either EZH2 or EZH1. Tumorigenic functions of EZH2 and its synthetic lethality with some subunits of SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeling complexes have been observed. However, little is known about the function of EZH1 in tumorigenesis. Herein, we developed novel, orally bioavailable EZH1/2 dual inhibitors that strongly and selectively inhibited methyltransferase activity of both EZH2 and EZH1. EZH1/2 dual inhibitors suppressed trimethylation of histone H3 lysine 27 in cells more than EZH2 selective inhibitors. They also showed greater antitumor efficacy than EZH2 selective inhibitor in vitro and in vivo against diffuse large B-cell lymphoma cells harboring gain-of-function mutation in EZH2. A hematological cancer panel assay indicated that EZH1/2 dual inhibitor has efficacy against some lymphomas, multiple myeloma, and leukemia with fusion genes such as MLL-AF9, MLL-AF4, and AML1-ETO. A solid cancer panel assay demonstrated that some cancer cell lines are sensitive to EZH1/2 dual inhibitor in vitro and in vivo. No clear correlation was detected between sensitivity to EZH1/2 dual inhibitor and SWI/SNF mutations, with a few exceptions. Severe toxicity was not seen in rats treated with EZH1/2 dual inhibitor for 14 days at drug levels higher than those used in the antitumor study. Our results indicate the possibility of EZH1/2 dual inhibitors for clinical applications.

Response Characteristics and Retinal Origin of the Photopic Negative Response of the Electroretinogram in Dogs

PURPOSE

To investigate the response characteristics and retinal origin of the photopic negative response (PhNR) of the electroretinograms (ERGs) in dogs.

METHODS

Photopic ERGs were elicited by white flash stimuli of different intensities under a steady white background illumination in four anesthetized dogs. These ERGs were also recorded in the same manner after intravitreal injection of tetrodotoxin (TTX). Additionally, retinal localization of voltage-gated sodium channel Nav 1.6 was assessed by immunohistochemistry.

RESULTS

The amplitude of the a-wave and the PhNR was increased as the stimulus intensity was raised, while the amplitude of the b-wave was peaked at the moderate stimulus intensity of 3.09 cd·s/m². TTX greatly attenuated the PhNR, while the reduction in the b-waves and a-wave was mild or insignificant. Nav 1.6-expression was specifically detected on the retinal ganglion cells (RGCs).

CONCLUSIONS

Our results are consistent with the PhNR primarily derived from the inner retina including RGCs in dogs, suggesting that the PhNR can be used to monitor function of these retinal components in dogs.

Rational Tuning of Visual Cycle Modulator Pharmacodynamics

Modulators of the visual cycle have been developed for treatment of various retinal disorders. These agents were designed to inhibit retinoid isomerase [retinal pigment epithelium-specific 65 kDa protein (RPE65)], the rate-limiting enzyme of the visual cycle, based on the idea that attenuation of visual pigment regeneration could reduce formation of toxic retinal conjugates. Of these agents, certain ones that contain primary amine groups can also reversibly form retinaldehyde Schiff base adducts, which contributes to their retinal protective activity. Direct inhibition of RPE65 as a therapeutic strategy is complicated by adverse effects resulting from slowed chromophore regeneration, whereas effective retinal sequestration can require high drug doses with potential off-target effects. We hypothesized that the RPE65-emixustat crystal structure could help guide the design of retinaldehyde-sequestering agents with varying degrees of RPE65 inhibitory activity. We found that addition of an isopropyl group to the central phenyl ring of emixustat and related compounds resulted in agents effectively lacking in vitro retinoid isomerase inhibitory activity, whereas substitution of the terminal 6-membered ring with branched moieties capable of stronger RPE65 interaction potentiated inhibition. The isopropyl derivative series produced discernible visual cycle suppression in vivo, albeit much less potently than compounds with a high affinity for the RPE65 active site. These agents were distributed into the retina and formed Schiff base adducts with retinaldehyde. Except for one compound [3-amino-1-(3-isopropyl-5-((2,6,6-trimethylcyclohex-1-en-1-yl)methoxy)phenyl)propan-1-ol (MB-007)], these agents conferred protection against retinal phototoxicity, suggesting that both direct RPE65 inhibition and retinal sequestration are mechanisms of potential therapeutic relevance.

Comparison of photopic negative response (PhNR) between focal macular and full-field electroretinograms in monkeys

PURPOSE

To compare the characteristics of the photopic negative response (PhNR) between the focal macular and full-field electroretinograms (ERGs) in monkeys.

METHODS

Both focal macular and full-field photopic ERGs were recorded in four cynomolgus monkeys under identical stimulus and recording conditions except for which area of the retina was illuminated. The luminance and duration of red flash stimuli were varied in the presence of steady blue background illumination. These ERGs were recorded before and after intravitreal injection of tetrodotoxin (TTX).

RESULTS

Several differences were identified between the focal macular and full-field ERGs, including: (1) The PhNR/b-wave amplitude ratio was higher in the focal macular than in the full-field ERGs, and (2) the stimulus threshold of the focal macular PhNR was lower than that of the full-field PhNR. For both macular and full-field stimulation conditions, (1) PhNR amplitude generally increased with increasing stimulus luminance; (2) PhNR implicit time was independent of the stimulus luminance; (3) PhNR amplitude and implicit time increased with increasing stimulus duration up to 50 ms, while a further increase in stimulus duration produced no change in amplitude or implicit time; and (4) PhNR amplitude was selectively attenuated by TTX.

CONCLUSIONS

Both the focal macular and full-field PhNRs reflect the functional properties of the inner retina including the retinal ganglion cells (RGCs). Relative to the b-wave, the contribution is weighted more heavily in the focal macular than in the full-field PhNR. Furthermore, these results support the idea that the focal macular PhNR can be an indicator of the function of the macular RGCs.

N-Methyl-N-Nitrosourea-Induced Acute Alteration of Retinal Function and Morphology in Monkeys

PURPOSE

The purpose of this study was to investigate both functional and morphologic alteration of the retina acutely induced by N-methyl-N-nitrosourea (MNU) in monkeys.

METHODS

The MNU was administered intravenously at a single dose of 40 mg/kg to six cynomolgus monkeys, and standard full-field electroretinograms (ERGs) were recorded 1, 3, and 7 days after dosing. In addition, the rod and cone a-waves in response to high-intensity flashes were analyzed by the a-wave fitting model (a-wave analysis). The photopic negative response (PhNR) was also recorded at the same time points. Furthermore, the retinas of two animals each were examined histopathologically 1, 3, or 7 days after dosing.

RESULTS

The MNU attenuated all the standard full-field ERGs including the rod-driven and cone-driven responses; in the combined rod-cone response, the b-wave was more affected than the a-wave. In the a-wave analysis, the sensitivity parameters (S) of the rod and cone a-waves had decreased on the day after dosing and remained unchanged thereafter. The maximum response parameter (Rmax) of the rod a-wave gradually decreased. On the other hand, the Rmax in the cone a-wave transiently increased on the day after dosing and decreased thereafter; the PhNR amplitude showed a similar time course change. Histopathologically, the retinal lesion on the day after dosing mainly consisted of pyknosis and karyorrhexis in the photoreceptor nucleus. Depletion of some photoreceptor nuclei, and shortening and disorientation of the photoreceptor segments became prominent at 3 and 7 days after dosing. Localization of degenerated photoreceptors was consistent with that of rhodopsin-positive photoreceptors, resulting in a well-preserved central fovea.

CONCLUSIONS

Our results indicated that MNU acutely induced rod-dominant photoreceptor degeneration in monkey retinas, but the photoreceptor function was impaired in both the rods and cones. Functional involvement of the postreceptoral components was also indicated.

Efficacy of conversion gastrectomy following docetaxel, cisplatin, and S-1 therapy in potentially resectable stage IV gastric cancer

BACKGROUND

Recent advances in gastric cancer chemotherapy have made macroscopic complete resection possible in some patients with stage IV disease.

METHODS

We retrospectively investigated the efficacy of multimodal therapy with combined docetaxel, cisplatin, and S-1 (DCS) and conversion gastrectomy in 57 patients with stage IV gastric cancer.

RESULTS

Of the 57 patients, 15 patients were categorized into potentially resectable case, which is defined as patients with single incurable factor including the upper abdominal para-aortic lymph node metastasis (16a2b1 PAN metastasis) or fewer than three peripheral liver metastases. The other 42 were categorized as initially unresectable. All of patients underwent DCS therapy, and then 34 patients underwent conversion gastrectomy. The 3-year overall survival (OS) rate among the patients who underwent conversion gastrectomy was 50.1% with MST of 29.9 months. They had significantly longer OS than patients who underwent DCS therapy alone (p < 0.01). Univariate analysis among the patents with conversion gastrectomy identified 16a2b1PAN metastasis, peritoneal metastasis, potential resectable case, R0 resection as significant prognostic factors. A 3-year OS in potential resectable cases was 92.9%. Multivariate analysis identified potential resectability as the only independent prognostic factor contributing to OS (HR 0.133, 95%CI 0.024-0. 744, p = 0.021). In contrast, clinical response was selected as the only independent prognostic factor in the subgroup of initially unresectable cases (HR 0.354, 95%CI 0.151-0.783, p = 0.021).

CONCLUSION

Patients with potentially resectable disease had a remarkably good prognosis among stage IV gastric cancer patients, and might be ideal candidates for conversion gastrectomy following DCS therapy.

Investigation of the teratogenic potential of VLA-4 antagonist derivatives in rats

Very late antigen-4 (VLA-4), which is concerned with cell-cell adhesion, plays important roles in development of the heart, and some VLA-4 antagonists cause cardiac anomalies. In this study, we evaluated the teratogenic potential of VLA-4 antagonist derivatives as screening, and investigated the conditions that induce cardiac anomalies. Seventeen compounds were orally administered to pregnant rats throughout the organogenesis period, and fetal examinations were performed. In addition, drug concentrations in the embryos were assayed. As a result, the incidence of ventricular septal defect (VSD) ranged from 0 to 100% depending on the compound. Plasma drug concentrations in the dams were related to increased incidence of VSD; however, these incidences were not increased when the concentration of the compound in the embryos at 24h after dosing was low. It is considered that continuous pharmacological activity in the embryo for more than 24h might disrupt closure of the ventricular septum.

Neutrophil gelatinase-associated lipocalin, a sensitive urinary biomarker of acute kidney injury in dogs receiving gentamicin

A sensitive urinary biomarker for acute kidney injury (AKI) was investigated in beagle dogs with nephrotoxicity induced by gentamicin. Gentamicin sulphate at 25 or 50 mg/kg was injected (s.c.) for 9 days, and conventional urinalysis, ELISA assay of neutrophil gelatinase-associated lipocal (NGAL) in urine, blood chemistry, and pathological examinations were performed. The dog given gentamicin at 25 mg/kg only showed slight deposition of lysosomal granules in the proximal tubular epithelium of the kidneys without any other significant changes even though urinary NGAL was elevated on Day 10 (day of necropsy). In the dog receiving gentamicin at 50 mg/kg, increases in urinary NGAL were observed on Days 3 and 5, and absence of urination, marked increases in serum urea nitrogen and creatinine, enlargement and discoloration of the kidneys with marked necrosis, and swelling of proximal epithelium were observed. In conclusion, urinary NGAL is considered to be a candidate as a sensitive predictable biomarker of AKI in the gentamicin-induced nephrotoxicity model in dogs.

Thioacetamide-induced Hepatocellular Necrosis Is Attenuated in Diet-induced Obese Mice

To assess modification of thioacetamide-induced hepatotoxicity in mice fed a high-fat diet, male C57BL/6J mice were fed a normal rodent diet or a high-fat diet for 8 weeks and then treated once intraperitoneally with thioacetamide at 50 mg/kg body weight. At 24 and 48 hours after administration, massive centrilobular hepatocellular necrosis was observed in mice fed the normal rodent diet, while the necrosis was less severe in mice fed the high-fat diet. In contrast, severe swelling of hepatocytes was observed in mice fed the high-fat diet. In addition, mice fed the high-fat diet displayed more than a 4-fold higher number of BrdU-positive hepatocytes compared with mice fed the normal rodent diet at 48 hours after thioacetamide treatment. To clarify the mechanisms by which the hepatic necrosis was attenuated, we investigated exposure to thioacetamide and one of its metabolites, the expression of CYP2E1, which converts thioacetamide to reactive metabolites, and the content of glutathione S-transferases in the liver. However, the reduced hepatocellular necrosis noted in mice fed the high-fat diet could not be explained by the differences in exposure to thioacetamide or thioacetamide sulfoxide or by differences in the expression of drug-metabolizing enzymes. On the other hand, at 8 hours after thioacetamide administration, hepatic total glutathione in mice fed the high-fat diet was significantly lower than that in mice fed the normal diet. Hence, decreased hepatic glutathione amount is a candidate for the mechanism of the attenuated necrosis. In conclusion, this study revealed that thioacetamide-induced hepatic necrosis was attenuated in mice fed the high-fat diet.

Thoracoscopic esophagectomy with extended lymph node dissection in the left lateral position: technical feasibility and oncologic outcomes

The aim of this study was to estimate the technical and oncologic feasibility of video-assisted thoracoscopic radical esophagectomy (VATS) in the left lateral position. From January 2003 to December 2011, 132 patients with esophageal cancer underwent VATS. The mean duration of the thoracic procedure and the entire procedure was 294 ± 88 and 623 ± 123 minutes, respectively. Mean blood loss during the thoracic procedure and the entire procedure was 313 ± 577 and 657 ± 719 g, respectively. The mean number of dissected thoracic lymph nodes was 32.6 ± 12.9. There were four in-hospital deaths (3.0%); two patients (1.5%) died of acute respiratory distress syndrome and two patients (1.5%) died of tumor progression. Postoperative unilateral or bilateral recurrent laryngeal nerve (RLN) palsy, or pneumonia was found in 33 (25.0%), 21 (15.9%), and 27(20.5%) patients, respectively. The patients were divided into the first 66 patients who underwent VATS (Group 1) and the subsequent 66 patients (Group 2). The numbers of cases who underwent neoadjuvant or induction chemotherapy for T4 tumor and intrathoracic anastomosis were higher in Group 2 than in Group 1. The duration of the procedure, amount of blood loss, and the number of dissected thoracic lymph nodes were not different between the two groups. The total number of dissected lymph nodes was higher in Group 2 than in Group 1 (72.6 ± 27.8 vs. 62.6 ± 21.6, P = 0.023). The rate of bilateral RLN palsy was less in Group 2 than in Group 1 (7.6% vs. 24.2%, P = 0.042). The mean follow-up period was 38.7 months. Primary recurrence consisted of hematogenous, lymphatic, peritoneal dissemination, pleural dissemination, and locoregional in 15 (11.3%), 20 (15.1%), 3 (2.3%), 4 (3.0%), and 5 patients (3.8%), respectively. The rate of regional lymph node recurrence within the dissection field was only 4.5%. The prognosis of patients with lymph node metastasis was significantly poorer than that of patients without lymph node metastasis. However, the prognosis of the 11 cases that had metastasis only around RLNs was similar to that of node-negative cases. Thirteen patients with pathological remnant tumor (R1 or R2) did not survive longer than 5 years at present. The overall 5-year survival rate of stage I, II, and III disease after curative VATS was 82.2%, 77.0%, and 52.3%, respectively. Expansion of VATS criteria for patients after induction chemotherapy for T4 tumor or thoracoscopic anastomosis did not adversely affect the surgical results by experience. Although the VATS procedure is accompanied by a certain degree of morbidity including RLN palsy and pulmonary complications, VATS has an excellent locoregional control effect. In addition, the favorable survival after VATS shows that the procedure is oncologically feasible.

Abstract OT1-1-01: A phase II study of neoadjuvant epirubicin/cyclophosphamide (EC) followed by weekly nanoparticle albumin-bound paclitaxel with or without trastuzumab for node-positive breast cancer

Background: Paclitaxel is considered standard treatment for metastatic breast cancer (MBC) and is often used as adjuvant and neoadjuvant chemotherapy for patients with early-stage disease. Conventional paclitaxel requires solvents such as polyoxyethylated castor oil; however, such solvents are associated with toxicity including peripheral neuropathy and hypersensitivity reaction. Moreover, the use of the drug requires special tubing and in-line filters. Therefore, nanoparticle albumin-bound paclitaxel (nab-PTX) requiring no solvent has been developed. Nab-PTX was effective in patients with MBC and as a neoadjuvant therapy. A comparison between weekly and triweekly nab-PTX suggested that weekly nab-PTX was superior in progression-free survival.

Trial design: This is a phase II trial to evaluate the efficacy and toxicity of neoadjuvant epirubicin/cyclophosphamide (EC) (epirubicin/cyclophosphamide) followed by weekly nab-PTX with or without trastuzumab for node-positive breast cancer. Patients receive four cycles of epirubicin (90 mg/m2) and cyclophosphamide (600 mg/m2) every 3 weeks, followed by four cycles of nab-PTX (125 mg/m2) on days 1, 8 and 15 in a 28-day cycle. Fifteen cycles of trastuzumab (2 mg/kg, loading 4 mg/kg) are added to the nab-PTX regimen in HER2-positive patients every week.

Eligibility criteria: Patients with histologically diagnosed invasive breast cancer based on a core needle biopsy of the T1-4 N1-3 without previous operation or chemotherapy are included in this trial. Eligible patients are aged between 20 years and 70 years with a performance status of 0 to 2 and adequate organ functions.

Specific aims: The primary endpoint is the pathologic complete response (pCR) rate in the breast and axilla, and the secondary endpoints are the breast conserving rate, toxicities, feasibility and overall survival.

Statistical methods: The sample size was calculated using the Simon method, with a type I error of 10% and a study power of 80%. 1. HER2-negative patients

The expected rate of pCR was 25% and the required number of patients was estimated to be 33. 2. HER2-positive patients

The expected rate of pCR was 50%, and the required number of patients was estimated to be 21.

Present and target accrual: Patient accrual within two medical centers started in April 2011 with 20 patients being on study to date (2012, June 12). A total of 56 patients (22 are HER2-positive and 34 are HER2-negative) are planned to be enrolled in the trial.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr OT1-1-01.

Mechanism of voriconazole-induced transient visual disturbance: reversible dysfunction of retinal ON-bipolar cells in monkeys

PURPOSE

To investigate the mechanism of voriconazole-induced transient visual disturbance in humans.

METHODS

andard full-field electroretinograms (ERGs) were recorded from monkeys treated intravenously with voriconazole. In addition, photopic ERGs elicited by long-duration stimuli (ON-OFF response) were also recorded from monkeys receiving intravenous voriconazole or intravitreal 2-amino-4-phosphonobutyric acid (APB).

RESULTS

aracteristic changes were observed in the waveform of the standard full-field ERGs obtained immediately after dosing of voriconazole as follows: electronegative combined rod-cone response (markedly attenuated b-wave and oscillatory potentials), undetectable rod response (eliminated b-wave); slightly abnormal single-flash cone response (flattened appearance in the bottom of the a-wave, mildly attenuated b-wave); and slightly abnormal 30 Hz flicker (mildly attenuated b-wave). The above changes fully recovered to baseline 24 hours after each dosing, along with a decrease in plasma voriconazole concentration. In addition, the change in the waveform of the ON-OFF response recorded in voriconazole-treated monkeys was quite similar to that recorded in APB-treated monkeys as follows: the b-wave was eliminated or prominently attenuated; and the a- and d-waves were not apparently attenuated.

CONCLUSIONS

The results strongly suggest that voriconazole induces selective and reversible dysfunction of the retinal ON-bipolar cells in both the rod and cone pathways in monkeys. From the results obtained in monkeys in this study, it is suggested that the function of the retinal ON-bipolar cells was selectively and reversibly affected in voriconazole-treated humans who complained of transient visual disturbances.

Comprehensive analysis of hepatic gene and protein expression profiles on phenobarbital- or clofibrate-induced hepatic hypertrophy in dogs

In order to characterize the hepatic effects of phenobarbital (PB) and clofibrate (CPIB) in dogs, PB and CPIB were administered to male beagle dogs for 14 days, and biochemical and histopathological examinations and comprehensive genomic and proteomic analyses, including GeneChip analysis and proteomics analysis using the 2-dimension difference gel electrophoresis (2D-DIGE) technique, were performed. Both compounds caused centrilobular hepatocellular hypertrophy, which were related to smooth endoplasmic reticulum (SER) proliferation in PB-treated dogs and to mitochondrial proliferation in CPIB-treated dogs. In the PB-treated dogs, drug-metabolizing enzyme induction was observed by Western blot and genomic analyses. CYP proteins could not be detected by the 2D-DIGE analysis, but increases in several endoplasmic reticulum (ER)-related proteins were observed. In the CPIB-treated dogs, drug-metabolizing enzyme induction was not clearly observed by any of Western blot, genomic and proteomic analyses. Genomic and proteomic analyses revealed that mitochondrial genes and proteins, including carnitine palmytoiltransferase II, acyl-CoA deheydrogenase and hydroxyacyl-CoA dehydrogenase, pyruvate carboxylase and ATP synthase beta chain were induced. There is a relatively good correlation among the morphology and the genomic and proteomic data, but some differences exist between the genomic and proteomic data. Comprehensive evaluation using these techniques in addition to morphological evaluation may provide a useful tool for safety assessment of the liver.

Epirubicin and cyclophosphamide (EC) followed by weekly paclitaxel with/without trastuzumab as primary systemic therapy in locally advanced breast cancer: Phase II study

e11590

Background: Primary systemic therapy (PST) has become a standard therapy for locally advanced breast cancer (LABC). The aim of this study was to evaluate the activity and toxicity of EC (epirubicin/cyclophosphamide) followed by weekly paclitaxel with/without trastuzumab as PST in LABC. Methods: Primary endpoint was pathologic complete response (pCR) rate in the breast and axilla, and secondary endpoints were breast conserving rate and toxicities. Patients with histologically diagnosed invasive breast cancer by core needle biopsy of the T2–4 (>3 cm) or N1–3 were included in this study. Eligible patients were age >20 years, had a performance status of 0 to 1, and had adequate organ functions. It was determined that the expected rate of pCR in the trial was 25%, and the sample size was calculated using the Simon method, with a type I error of 5% and a study power of 80%. The target enrollment was estimated to be 40 evaluable patients. Treatment: Patients received epirubicin (100 mg/m2) and cyclophosphamide (600mg/m2 ) every 3 weeks for four cycles followed by paclitaxel (80 mg/m2 ) every week for 12 cycles. Trastuzumab (2mg/kg) was added to paclitaxel in HER2-positive patients. Results: Forty-three patients were enrolled into this study and 3 patients withdrew. pCR were observed in 8 patients and pCR rate was 20.0% (95% confidence interval, 7.6- 32.4). Twenty-four patients (60.0%) underwent breast conserving surgery. In particular, patients with HER2 positive tumor had significantly higher rate of pCR than the others (62.5% vs. 8.6%; p=0.0014). Grade 4 neutropenia was recorded in 27.5% of the patients, and febrile neutropenia occurred in 4 patients (10.0%). No heart failure was seen. Conclusions: EC followed by weekly paclitaxel with/without trastuzumab was an active and well-tolerated treatment for LABC.

No significant financial relationships to disclose.

Expression of a CD44 variant and VEGF-C and the implications for lymphatic metastasis and long-term prognosis of human breast cancer

The aim of the present study was to determine whether expression of the CD44 variant v7-v8 (CD44v7-v8) or vascular endothelial growth factor-C (VEGF-C) is associated with long-term prognosis in breast cancer patients. A 10-year follow-up of 91 patients with primary breast cancer who were previously assessed for CD44 expression was undertaken. Immunohistochemical evaluation of VEGF-C expression was performed in 87 of these patients and their long-term prognosis was assessed. The disease-free and overall survival rates were significantly poorer for the CD44v7-v8-positive patients than for the patients negative for this marker. VEGF-C expression was detected in 38 out of the 87 patients (43.7%) with primary human breast cancer. There were no significant differences in tumor size, histological type, axillary lymph node status, presence of lymphatic or venous invasion, or presence of estrogen receptors and progesterone receptors between the VEGF-C-positive and -negative patients. There were also no significant differences in the disease-free or overall survival rates in these patient groups. In conclusion after the 10-year follow-up, expression of CD44v7-v8 was associated with poor prognosis for breast cancer patients. However, there was no association between VEGF-C expression and the clinicopathological factors or prognosis of breast cancer patients.

An economic evaluation of recombinant bovine somatotropin approval in Japan

A comprehensive econometric model was developed to evaluate potential impacts of recombinant bovine somatotropin (rbST) approval in Japan. Three novel features of the analyses include 1) investigation of impact of rbST on herd-size structure, 2) determination of economic feasibilities of rbST adoption by herd size, and 3) evaluation of policies to mitigate negative effects of rbST approval. Simulation analysis was conducted over a 10-yr projected period assuming rbST was approved in Japan in 2001. Nine hypothetical scenarios were simulated to examine sensitivity of simulation results. Simulation results indicate that rbST approval would accelerate structural change in Japan's dairy industry toward fewer, larger farms. Negative effects of rbST on farm income are projected to be more severe for smaller farms, because of higher costs, lower profit-earning ability, lower milk yields, and lower adoption rates of rbST. Larger farms benefit from rbST adoption if milk demand is maintained. However, if concerns about rbST induce significant milk demand decreases, even the largest farms' income and cow numbers will decrease. Thus, Japan's dairy industry could be caught in a double downward spiral of declining milk prices and production. Assuming rbST is approved, small farms would benefit by using the technology, but they fare best if rbST is not approved. Two policies could be effective in mitigating possible farm income losses. First, lost farm income can be offset if dairy cooperatives can exercise greater market power to control fluid milk marketings. Second, because generic milk advertising has positive effects on both milk demand and farm income, increasing check-off rates to fund more advertising could ease farm income losses.

EGFR, c-erbB2 and p53 protein in the primary lesions and paired metastatic regional lymph nodes in breast cancer

AIMS

Various biological parameters are now being evaluated as predictors for the response of chemohormonal therapy for breast cancer. Few studies compare these parameters between the primary lesions and metastatic regional lymph nodes of breast cancer.

METHODS

Immunohistochemical analyses for epidermal growth factor receptor (EGFR), c-erbB2 and p53 protein were performed on the primary lesions and matching metastatic regional lymph nodes of 107 breast cancers. The intensity of the immunoreactivity was graded for heterogeneous or 10-50% staining, and diffuse or >50% staining.

RESULTS

EGFR, c-erbB2 and p53 protein showed a concordance between the primary lesions and matching regional lymph nodes in terms of a negative or positive finding (+ and ++) in 98 (92%) of 106 cases, 76 (100%) of 76 cases and 79 (93%) of 85 cases respectively, while EGFR, c-erbB2 and p53 protein also showed a concordance in the intensity of the immunoreactivity in 24 (89%) of 27 cases 14 (74%) of 19 cases and 30 (94%) of 32 cases respectively. In 21 of 24 cases which showed a disconcordance in the positivity or the intensity of the positivity of EGFR, c-erbB2 and p53 protein, one of the primary lesions and matching regional lymph nodes showed heterogeneous or 10-50% immunostaining.

CONCLUSIONS

The immunoreactivity of EGFR, c-erbB2 and p53 protein shows a concordance between the primary lesions and matching metastatic regional lymph nodes in a majority of breast cancers.

A novel variant of WISP1 lacking a Von Willebrand type C module overexpressed in scirrhous gastric carcinoma

Scirrhous carcinoma of the stomach is characterized by rapid growth with a vast fibrous stroma, high invasiveness, and substantially a poor prognosis. Little is known of the molecular pathogenesis of this disease. Members of the emerging family of the CCN gene (for connective tissue growth factor, cysteine-rich 61, nephroblastoma overexpressed) encode cysteine-rich secreted proteins with roles in human fibrotic disorders and cancer progression. Using targeted differential displays, we identified a novel variant of the CCN family member WISP1 (Wnt-induced secreted protein 1), named WISP1v, as overexpressed in scirrhous gastric carcinomas. Predicted protein of the WISP1v completely lacks a module of Von Willebrand type C that is thought to participate in protein complex formation. Ectopic expression revealed WISP1v to be a secreted oncoprotein inducing a striking cellular transformation and rapid piling-up growth. It is noteworthy that WISP1v transfectants enhanced the invasive phenotype of co-cultured gastric carcinoma cells, while wild-type WISP1 had no such potential. These findings suggest that CCN protein WISP1v is involved in the aggressive progression of scirrhous gastric carcinoma.

[Effect of G-CSF (nartograstim) on neutropenia (leukopenia) induced by taxane in metastatic breast cancer--time-course changes in neutrophil and leukocyte counts]

Since 1997, we have used docetaxel and paclitaxel as the second-line and third-line chemotherapies against anthracycline-resistant metastatic breast cancer. However, these taxane compounds induced neutropenia and leukopenia, which may be reversed by G-CSF (Nartograstim). We thus examined the therapeutic efficacy of nartograstim for time-course changes in neutrophil and leukocyte counts in these patients. No difference was observed in neutrophil or leukocyte count whether the patient was treated with docetaxel or paclitaxel. Neutrophil and leukocyte counts reached a nadir on days 7 to 8 after administration. With a 5-6 day administration of nartograstim, neutrophil or leukocyte counts recovered by the second or third day after the nadir, indicating that the chemotherapy was given safely with nartograstim. In these same patients receiving a given treatment cycle, the number of days until reaching the nadir were almost identical for neutrophils and leukocytes; however, the duration of the nadir and the time to count recovery was significantly longer for neutrophils than for leukocytes. In the clinical setting, the parameter "leukocyte count" has been occasionally used for evaluation of the severity of myelosuppression, because the data is more readily available. However, at least during the nadir, the "neutrophil count" should be used as the parameter of choice.

Effects of erbium, chromium:YSGG laser irradiation on root surface: morphological and atomic analytical studies

OBJECTIVE

The purpose of this study was to investigate the morphological and atomic changes on the root surface by stereoscopy, field emission-scanning electron microscopy (FE-SEM), and energy dispersive X-ray spectroscopy (SEM-EDX) after erbium, chromium:yttrium, scandium, gallium, garnet (Er,Cr:YSGG) laser irradiation in vitro.

SUMMARY BACKGROUND DATA

There have been few reports on morphological and atomic analytical study on root surface by Er,Cr:YSGG laser irradiation.

METHODS

Eighteen extracted human premolar and molar teeth were irradiated on root surfaces at a vertical position with water-air spray by an Er,Cr:YSGG laser at the parameter of 5.0 W and 20 Hz for 5 sec while moving. The samples were then morphologically observed by stereoscopy and FE-SEM and examined atomic-analytically by SEM-EDX.

RESULTS

Craters having rough but clean surfaces and no melting or carbonization were observed in the samples. An atomic analytical examination showed that the calcium ratio to phosphorus showed no significant changes between the control and irradiated areas (p > 0.01).

CONCLUSIONS

These results showed that the Er,Cr:YSGG laser has a good cutting effect on root surface and causes no burning or melting after laser irradiation.

[Analysis of factors related to the high incidence of tuberculosis in the city of Wakayama--analysis according to age groups, and sputum test results]

Over the last 20 years, the decrease in the incidence of Tuberculosis (TB) in Japan has slowed down. As of 1999, the incidence rate was 34.6 per 100,000 population in Japan, which was higher than that of the other developed countries, and the incidence rate in the city of Wakayama, one of the prefectural capital cities in Japan, during the same period was 42.9 per 100,000 population. We investigated the causes of this high incidence rate of TB in Wakayama City according to the analysis by age groups and sputum test results when patients are newly registered. Comparing our data during the period from 1.1.1998 to 12.31.1999 with data during the same period in the whole country and the rest of Wakayama Pref., the following results were obtained. Observing by age-groups, the incidence of TB in Wakayama City as well as in the rest of Wakayama Pref. and in the whole country was highest in the age-group above 70 years of age, though the rate of Wakayama City was significantly higher (146.2 per 100,000 population) than that in the rest of Wakayama Pref. (98.5 per 100,000 population) and that in the whole country (90.3 per 100,000 population). Furthermore, the incidence rate of cases diagnosed as TB without bacteriological proof in Wakayama City (57.1 per 100,000 population) was significantly higher than that of the whole country (33.7 per 100,000 population). Therefore, we concluded that one of the causes of high incidence of TB in Wakayama City was due to inappropriate method of diagnosing TB. More extensive use of sputum examination and strict evaluation of cases without bacteriological proof are desirable to increase the accuracy of TB diagnosis in Wakayama City.

Clinical significance of vascular endothelial growth factor-C (VEGF-C) in breast cancer

Vascular endothelial growth factor-C (VEGF-C) is a specific ligand which induces lymphangiogenesis. We examined the expression of VEGF-C protein to determine its role in the progression of breast cancer. Immunohistochemical analysis revealed that VEGF-C was overexpressed in 39 of 98 breast cancer specimens (39.8%) but not in adjacent normal mammary glands. The expression of VEGF-C showed a significant correlation with lymphatic vessel invasion (p = 0.0004). It is noteworthy that the 5-year disease free survival rate of the VEGF-C positive group was significantly poorer than that of negative group (p = 0.0356). We suggest that as expression of VEGF-C is not implicated in lymphatic spread, it may prove to be a promising marker to predict the recurrence of breast cancer.

Endoscopic extirpation of benign breast tumors using an extramammary approach

BACKGROUND

Skin incision has been made directly in the breast for treatment of benign breast tumor in spite of the young age of the patient population.

METHODS

Small incisions (12 mm, 5 mm, and 2 mm) were made in the extramammary line, and the benign tumors (diagnosed by imaging and aspiration needle cytology) were endoscopically extirpated.

RESULTS

The mean age of 36 patients was 27.6 years, and the mean mass size was 3.6 cm (7 masses at maximum). The average operation time per mass was 2.6 hours in the first 18 operations and 1.4 hours in the latter 19 operations. Overall blood loss was 19 mL. Postoperative complications were seen in 2 patients: an extended subcutaneous emphysema due to excessive CO2 gas inflation and a mild burn, both of which were reversible. All patients were extremely satisfied with the cosmetic results of the procedure.

CONCLUSIONS

Endoscopic removal by the extramammary approach is the best option for benign breast tumors considering the patient's age and the excellent cosmetic results.

Removal of gingival melanin pigmentation with the semiconductor diode laser: a case report

OBJECTIVE

This investigation was performed to evaluate the possibility of the removal of canine gingival melanin pigmentation with the semiconductor diode (SCD) laser in vivo.

SUMMARY BACKGROUND DATA

Recently, a semiconductor laser, which can ablate soft tissue, has been developed. It is already used in dentistry as well as in medicine.

METHODS

The SCD laser was irradiated on the pigmented area of canine gingival surface with the irradiation output of 3W. The effect of the SCD laser irradiation was evaluated at the two intervals: immediately after irradiation and at 3 weeks following irradiation. In addition, histological examination was performed before irradiation and at the same intervals from the biopsies (4 microm) of unlased and lased areas.

RESULTS

The SCD laser was effective in removing melanin pigmentation. In histological examination, neither inflammatory cell nor any tissue damage was observed with hematoxylin-eosin staining. At 3 weeks, there was a continuous healing process with the proliferation of squamous epithelial cells.

CONCLUSIONS

SCD laser irradiation can be considered an alternative procedure for removal of melanin pigmentation.

Removal effects of the Nd:YAG laser and Carisolv on carious dentin

OBJECTIVE

The purpose of this study was to investigate the removal effect of the Nd:YAG laser irradiation and Carisolv on carious dentin.

BACKGROUND DATA

Many previous studies have reported several simple and alternative techniques, such as lasers and chemicals, for caries removal.

METHODS

Carisolv was applied on the surface of 20 extracted human anterior and molar teeth for 1 min and then the Nd:YAG laser was irradiated with a continuous water spray for another 1 min. The energy densities were varied from 2 to 6W with a repetition rate of 20 pps. As caries removal progressed, the cavity was carefully assessed by DIAGNOdent. Each lesion was photographed before and after treatment, and the treated cavity was observed microscopically using a stereoscope and with scanning electron microscope (SEM). Thermal change at the time of laser irradiation was measured by thermovision.

RESULTS

Our results revealed that application of Carisolv followed by Nd:YAG laser irradiation at 4-6W pulse energy effectively removed dentin caries. The total procedure was usually repeated once or twice for complete caries removal. From the SEM study, it was found that the cavity surface treated with the laser revealed various patterns of microirregularity, often accompanied by microfissure propagation. There was also no smear layer.

CONCLUSIONS

It was revealed that Nd:YAG laser and Carisolv could provide an alternative technique for caries removal instead of the conventional mechanical drilling and cutting.

Vascular endothelial growth factor-C (VEGF-C) expression in human colorectal cancer tissues

Vascular endothelial growth factor-C (VEGF-C) functions specifically to induce lymphangiogenesis. We examined the relationship between expression of VEGF-C and clinicopathological features in patients with colorectal cancer. The expression of VEGF-C in the 99 primary tumours and 18 metastatic lymph nodes from colorectal cancer patients was examined immunohistochemically. To verify VEGF-C mRNA expression, reverse transcriptase-polymerase chain reaction (RT-PCR) was carried out. The expression of VEGF-C correlated with lymphatic involvement, lymph nodes metastasis, and depth of invasion. On the other hand, correlations were nil with regard to gender of the patients, histologic type, venous involvement, and liver metastasis. The expression of VEGF-C in metastatic lymph nodes was fairly consistent with this expression in the primary tumour. Survival time was shorter for VEGF-C positive groups than for VEGF-C negative ones, but with no statistically significant difference. RT-PCR findings revealed that the expression of VEGF-C mRNA correlated mostly with that of VEGF-C protein expression. VEGF-C may play an important role in lymphatic spread of colorectal cancer.