Quantitative prediction of CYP3A-mediated drug-drug interactions by correctly estimating fraction metabolized using human liver chimeric mice

BACKGROUND AND PURPOSE

Fraction metabolized (fm ) and fraction transported (ft ) are important for understanding drug-drug interactions (DDIs) in drug discovery and development. However, current in vitro systems cannot accurately estimate in vivo fm due to inability to reflect the ft by efflux transporters (ft,efflux ). This study demonstrates how CYP3A-mediated DDI for CYP3A/P-gp substrates can be predicted using Hu-PXB mice as human liver chimeric mice.

EXPERIMENTAL APPROACH

For estimating human in vitro fm by CYP3A enzyme (fm,CYP3A,in vitro ), six drugs, including CYP3A/P-gp substrates (alprazolam, cyclosporine, docetaxel, midazolam, prednisolone, and theophylline) and human hepatocytes were incubated with or without ketoconazole as a CYP3A inhibitor. We calculated fm,CYP3A,in vitro based on hepatic intrinsic clearance. To estimate human in vivo fm,CYP3A (fm,CYP3A,in vivo ), we collected information on clinical DDI caused by ketoconazole for these six drugs. We calculated fm,CYP3A,in vivo using the change of total clearance (CLtotal ). For evaluating the human DDI predictability, the six drugs were administered intravenously to Hu-PXB and SCID mice with or without ketoconazole. We calculated the change of CLtotal caused by ketoconazole. We compared the CLtotal change in humans with that in Hu-PXB and SCID mice.

KEY RESULTS

The fm,CYP3A,in vitro was overestimated compared to the fm,CYP3A,in vivo . Hu-PXB mice showed much better correlation in the change of CLtotal with humans (R2  = 0.95) compared to SCID mice (R2  = 0.0058).

CONCLUSIONS AND IMPLICATIONS

CYP3A-mediated DDI can be predicted by correctly estimating human fm,CYP3A,in vivo using Hu-PXB mice. These mice could be useful predicting hepatic fm and ft,efflux .

Validation of a New Methodology to Create Oral Drugs beyond the Rule of 5 for Intracellular Tough Targets

Establishing a technological platform for creating clinical compounds inhibiting intracellular protein-protein interactions (PPIs) can open the door to many valuable drugs. Although small molecules and antibodies are mainstream modalities, they are not suitable for a target protein that lacks a deep cavity for a small molecule to bind or a protein found in intracellular space out of an antibody's reach. One possible approach to access these targets is to utilize so-called middle-size cyclic peptides (defined here as those with a molecular weight of 1000-2000 g/mol). In this study, we validated a new methodology to create oral drugs beyond the rule of 5 for intracellular tough targets by elucidating structural features and physicochemical properties for drug-like cyclic peptides and developing library technologies to afford highly N-alkylated cyclic peptide hits. We discovered a KRAS inhibitory clinical compound (LUNA18) as the first example of our platform technology.

Quantitative Prediction of OATP-Mediated Disposition and Biliary Clearance Using Human Liver Chimeric Mice

Drug biliary clearance (CLbile) in vivo is among the most difficult pharmacokinetic parameters to predict accurately and quantitatively because biliary excretion is influenced by metabolic enzymes, transporters, and passive diffusion across hepatocyte membranes. The purpose of this study is to demonstrate the use of Hu-FRG mice [Fah-/-/Rag2-/-/Il2rg-/- (FRG) mice transplanted with human-derived hepatocytes] to quantitatively predict human organic anion transporting polypeptide (OATP)-mediated drug disposition and CLbile To predict OATP-mediated disposition, six OATP substrates (atorvastatin, fexofenadine, glibenclamide, pitavastatin, pravastatin, and rosuvastatin) were administered intravenously to Hu-FRG and Mu-FRG mice (FRG mice transplanted with mouse hepatocytes) with or without rifampicin as an OATP inhibitor. We calculated the hepatic intrinsic clearance (CLh,int) and the change of hepatic clearance (CLh) caused by rifampicin (CLh ratio). We compared the CLh,int of humans with that of Hu-FRG mice and the CLh ratio of humans with that of Hu-FRG and Mu-FRG mice. For predicting CLbile, 20 compounds (two cassette doses of 10 compounds) were administered intravenously to gallbladder-cannulated Hu-FRG and Mu-FRG mice. We evaluated the CLbile and investigated the correlation of human CLbile with that of Hu-FRG and Mu-FRG mice. We found good correlations between humans and Hu-FRG mice in CLh,int (100% within threefold) and CLh ratio (R2 = 0.94). Moreover, we observed a much better relationship between humans and Hu-FRG mice in CLbile (75% within threefold). Our results suggest that OATP-mediated disposition and CLbile can be predicted using Hu-FRG mice, making them a useful in vivo drug discovery tool for quantitatively predicting human liver disposition. SIGNIFICANCE STATEMENT: OATP-mediated disposition and biliary clearance of drugs are likely quantitatively predictable using Hu-FRG mice. The findings can enable the selection of better drug candidates and the development of more effective strategies for managing OATP-mediated DDIs in clinical studies.

O-130 Reproductive outcomes of normal ovarian reserve patients after progestin-primed ovarian stimulation with chlormadinone acetate vs GnRH antagonist: A retrospective study with inverse-probability-of-treatment weighting

Study question

To evaluate the effectiveness of chlormadinone acetate (CMA) for preventing premature LH surge in patients with normal ovarian reserve compared to cetrorelix.

Summary answer

In progestin-primed ovarian stimulation (PPOS) than GnRH antagonist (GnRH-ant), the incidence of premature LH surge was significantly lower, without significant difference in oocyte maturation rate.

What is known already

The GnRH-ant protocol is one of the conventional protocols which has some disadvantages including increased premature LH surge rate and cancelation rate. In recent years, the PPOS protocol has attracted attention as a new ovarian stimulation using progestin as an alternative to GnRH analog for suppressing a premature LH surge, however its efficacy is still controversial. In addition, many studies have investigated the reproductive outcomes of PPOS using medroxy-progesterone acetate or dydrogesterone; however, there are few reports of CMA, an oral progestin, which is inexpensive and widely used in Japan.

Study design, size, duration

This retrospective cohort study was performed in a reproduction center between March 2018 and October 2020 which included 977 Japanese patients with normal ovarian reserve undergoing PPOS with CMA (n = 299), or GnRH antagonist (GnRH-ant) with cetrorelix (n = 608) in their first IVF cycle at the reproduction center. In subgroup analysis, pregnancy outcomes after frozen embryo transfers (FET) between PPOS (n = 284) and GnRH-ant (n = 579) were also compared.

Participants/materials, setting, methods

The inclusion criteria were patients aged < 40 years and AMH ≧ 1.1 ng/mL, who underwent autologous oocyte retrieval in their first IVF cycle with freeze-all strategy. The primary outcome was the incidence of premature LH surge, the secondary outcomes was oocyte maturation rate. To reduce the impact of treatment bias and potential confounding factors, we conducted logistic regression models with inverse-probability-of-treatment weighting (IPTW).

Main results and the role of chance

After IPTW, baseline clinical data were well-balanced between the two groups, including age, AMH, BMI, the duration, type, and cause of infertility, antral follicle count, the history of recurrent spontaneous abortion, and previous IVF attempts. The premature LH surge rate was significantly lower with PPOS (3.1%) compared to GnRH-ant (20.1%) (odds ratio, 0.21; 95% confidence interval, 0.11–0.36). No significant differences were found in total gonadotropin dose (2400IU for PPOS vs 2400IU for GnRH-ant, p = 0.136), the number of oocyte retrieval (n = 15 vs n = 15, p = 0.484), oocyte maturation rate (78.8% vs 77.8%, p = 0.275), fertilization rate (73.0% vs 72.0%, p = 0.412), viable embryo rate per oocyte retrieval (40% vs 40%, p = 0.890), and good quality blastocyst rate (72.0% vs 69.6%, p = 0.092). However, the good quality day-3 embryo rate was significantly lower with PPOS (37.2% vs 49.1%, p < 0.05). There were no differences in the incidence of moderate-to-severe OHSS (0.3% vs 0.7%, p = 0.481). In FET cycles, the pregnancy outcomes, such as implantation rate (43.1 % vs 51.9 %, p = 0.013) and clinical pregnancy rate (46.5% vs 54.7%, p = 0.027) were significantly lower with PPOS, however, no significant differences were found in ongoing pregnancy rate (75.6% vs 80.5%, p = 0.325), and live birth rate (72.4% vs 79.5 %, p = 0.142).

Limitations, reasons for caution

This was a retrospective cohort study conducted in a single center. The participants in this study were limited to Japanese ethnicity. The results need to be validated across different centers and other ethnicities.

Wider implications of the findings

This is the first report assessing the reproductive outcomes on PPOS using CMA, widely used in Japan. The PPOS with CMA significantly suppressed the premature LH surge rate compared to GnRH-ant protocol, without decrease in oocyte maturation rate.

Trial registration number

N/A

Quantitative prediction of P-glycoprotein-mediated drug-drug interactions and intestinal absorption using humanized mice

BACKGROUND AND PURPOSE

P-glycoprotein (P-gp) exhibits a broad substrate specificity and affects pharmacokinetics, especially intestinal absorption. However, prediction, in vivo, of P-gp-mediated drug-drug interaction (DDI) and non-linear absorption at the preclinical stage, is challenging. Here we evaluate the use of human MDR1 mouse artificial chromosome (hMDR1-MAC) mice carrying human P-gp and lacking their own murine P-gp to quantitatively predict human P-gp-mediated DDI and non-linear absorption.

EXPERIMENTAL APPROACH

The P-gp substrates (aliskiren, betrixaban, celiprolol, digoxin, fexofenadine and talinolol) were administered orally to wild-type, Mdr1a/b-knockout (KO) and hMDR1-MAC mice, and their plasma concentrations were measured. We calculated the ratio of area under the curve (AUCR) in mice (AUC_Mdr1a/b-KO /AUC_wild-type or AUC_Mdr1a/b-KO /AUC_hMDR1-MAC ) estimated as attributable to complete P-gp inhibition and the human AUCR with and without P-gp inhibitor administration. The correlations of AUCR_human with AUCR_wild-type and AUCR_hMDR1-MAC were investigated. For aliskiren, betrixaban and celiprolol, the K_m and V_max values for P-gp in hMDR1-MAC mice and humans were optimized from different dosing studies using GastroPlus. The correlations of K_m and V_max for P-gp between human and hMDR1-MAC mice were investigated.

KEY RESULTS

A better correlation between AUCR_human and AUCR_hMDR1-MAC (R²  = 0.88) was observed. Moreover, good relationships of K_m (R²  = 1.00) and V_max (R²  = 0.98) for P-gp between humans and hMDR1-MAC mice were observed.

CONCLUSIONS AND IMPLICATIONS

These results suggest that P-gp-mediated DDI and non-linear absorption can be predicted using hMDR1-MAC mice. These mice are a useful in vivo tool for quantitatively predicting P-gp-mediated disposition in drug discovery and development.

Stress Myocardial Perfusion Imaging Interpretation From the Viewpoint of Fractional Flow Reserve

BACKGROUND

Myocardial perfusion imaging (MPI) and fractional flow reserve (FFR) are established approaches to the assessment of myocardial ischemia. Recently, various FFR cutoff values were proposed, but the diagnostic accuracy of MPI in identifying positive FFR using various cutoff values is not well established.Methods and Results:We retrospectively studied 273 patients who underwent stress MPI and FFR within a 3-month period. Results for FFR were obtained from 218 left anterior descending artery (LAD) lesions and 207 non-LAD lesions. Stress MPI and FFR demonstrated a good correlation in the detection of myocardial ischemia. However, the positive predictive value (PPV) of FFR for detecting MPI-positive lesions at the optimal FFR thresholds was insufficient (44% for LAD and 65% for non-LAD lesions). This was caused by a sharp drop in PPV at an FFR threshold of 0.7 or more. Notably, 41% of the lesions with normal MPI demonstrated FFRs <0.80. However, MPI-negative lesions had an extremely low lesion rate with FFR <0.65 (6%). Conversely, 78% and 41% of MPI-positive lesions had FFR <0.80 and <0.65, respectively.

CONCLUSIONS

The data confirmed that decisions based on MPI are reasonable because MPI-negative patients have an extremely low rate of lesions with a FFR below the cutoff point for a hard event, and MPI-positive lesions include many lesions with FFR <0.65.

Effects of preemptive analgesia with intravenous acetaminophen on postoperative pain relief in patients undergoing third molar surgery: a prospective, single-blind, randomized controlled trial

BACKGROUND

The efficacy of preemptive analgesia in managing postoperative pain remains controversial. The aim of this study was to compare the efficacy of intravenous (IV) acetaminophen administered before or immediately after the surgical extraction of an impacted mandibular third molar.

MATERIAL AND METHODS

This prospective randomized clinical trial included 120 patients. The patients were assigned to one of three groups: the preoperative-treatment group (pre-group), which received 1000 mg of IV acetaminophen 20 min before surgery; the postoperative-treatment group (post-group), which received 1000 mg of IV acetaminophen after surgery; the no-treatment group (control-group), which did not receive any analgesic. Rescue analgesic (60 mg loxoprofen) was issued to each patient, with instructions on self-administration if needed. For the rescue medication usage, the time of first loxoprofen usage and the total amount of loxoprofen consumption were obtained for a 17-hour period after surgery. We measured pain using the visual analogue scale at 1 hour and at 2, 3, 4, 5, and 15 hours after surgery.

RESULTS

There was no significant difference in pain level among the three groups at any time interval. However, the pre-group demonstrated significantly lower rescue analgesic consumption and longer time until initial administration.

CONCLUSIONS

Administration of IV acetaminophen before third molar surgery provides more effective pain control than postoperative administration and no treatment.

Radial Spin Texture in Elemental Tellurium with Chiral Crystal Structure

The chiral crystal is characterized by a lack of mirror symmetry and inversion center, resulting in the inequivalent right- and left-handed structures. In the noncentrosymmetric crystal structure, the spin and momentum of electrons are expected to be locked in the reciprocal space with the help of the spin-orbit interaction. To reveal the spin textures of chiral crystals, we investigate the spin and electronic structure in a p-type semiconductor, elemental tellurium, with the simplest chiral structure by using spin- and angle-resolved photoemission spectroscopy. Our data demonstrate that the highest valence band crossing the Fermi level has a spin component parallel to the electron momentum around the Brillouin zone corners. Significantly, we have also confirmed that the spin polarization is reversed in the crystal with the opposite chirality. The results indicate that the spin textures of the right- and left-handed chiral crystals are hedgehoglike, leading to unconventional magnetoelectric effects and nonreciprocal phenomena.

Estimating Efflux Transporter-Mediated Disposition of Molecules beyond the Rule of Five (bRo5) Using Transporter Gene Knockout Rats

Transporter gene knockout models are a practical and widely used tool for pharmacokinetic studies in drug discovery. P-glycoprotein (P-gp) and breast cancer resistance protein (Bcrp) are major efflux transporters that control absorption and bioavailability, and are important when determining oral drug disposition. To the best of our knowledge, beyond the rule of five (bRo5) molecules launched on the market to date tend to be substrates for efflux transporters. The purpose of this study is to evaluate in vivo the impact of efflux transporters on the oral absorption process and systemic clearance using rats which lack P-gp and/or Bcrp expression. We administered five bRo5 substrates (asunaprevir, cyclosporine, danoprevir, ledipasvir, and simeprevir) intravenously or orally to wild-type and Mdr1a, Bcrp, and Mdr1a/Bcrp knockout rats, calculated the clearance, oral bioavailability, and absorption rate profile of each substrate, and compared the results. Systemic clearance of the substrates in knockout rats changed within approximately ±40% compared to wild-types, suggesting the efflux transporters do not have a significant influence on clearance in rats. On the other hand, the oral absorption of substrates in the knockout rats, especially those lacking Mdr1a, increased greatly-between 2- and 5-fold more than in wild-types. This suggests that rat efflux transporters, especially P-gp, greatly reduce the oral exposure of these substrates. Moreover, results on the absorption rate-time profile suggest that efflux transporters are constantly active during the absorption period in rats. Transporter knockout rats are a useful in vivo tool for estimating the transporter-mediated disposition of bRo5 molecules in drug discovery.

A candidate-SNP retrospective cohort study for fracture risk in Japanese Thoroughbred racehorses

Fractures are medical conditions that compromise the athletic potential of horses and/or the safety of jockeys. Therefore, the reduction of fracture risk is an important horse and human welfare issue. The present study used molecular genetic approaches to determine the effect of genetic risk for fracture at four candidate SNPs spanning the myostatin (MSTN) gene on horse chromosome 18. Among the 3706 Japanese Thoroughbred racehorses, 1089 (29.4%) had experienced fractures in their athletic life, indicating the common occurrence of this injury in Thoroughbreds. In the case/control association study, fractures of the carpus (carpal bones and distal radius) were statistically associated with g.65809482T/C (P = 1.17 x 10^-8 ), g.65868604G/T (P = 2.66 x 10^-9 ), and g.66493737C/T (P = 6.41 x 10^-8 ). In the retrospective cohort study using 1710 racehorses born in 2000, the relative risk (RR) was highest for male horses at g.65868604G/T, based on the dominant allele risk model (RR = 2.251, 95% confidence interval 1.407-3.604, P = 0.00041), and for female horses at g.65868604G/T, based on the recessive allele risk model (RR = 2.313, 95% confidence interval 1.380-3.877, P = 0.00163). Considering the association of these SNPs with racing performance traits such as speed, these genotypes may affect the occurrence of carpus fractures in Japanese Thoroughbred racehorses as a consequence of the non-genetic influence of the genotype on the distance and/or intensity of racing and training. The genetic information presented here may contribute to the development of strategic training programs and racing plans for racehorses that improve their health and welfare.

6108Efficacy of the PCSK9 inhibitor for lipid-rich coronary plaque reduction: a near-infrared spectroscopy analysis

Background

Recently, some studies have highlighted proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors produce incremental low-density lipoprotein cholesterol (LDL-C) lowering effect. However, it is unknown whether the lipid composition of plaque changes is associated with serum LDL-C reduction due to PCSK9 inhibitors administration.

Purpose

The purpose of this study was to determine the effects of PCSK9 inhibitor (PCSK9i) on coronary plaque component in patients with a history of coronary artery disease (CAD) assessed by near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS).

Methods

A total of 67 non-culprit coronary segments were identified in 34 patients. These lesions were analyzed utilizing NIRS-IVUS at baseline and follow-up coronary angiography (CAG). The subjects were divided into two groups according to lipid-lowering treatment; administration of PCSK9i group (PCSK9i: 19 segments, 9 patients) and traditional statin treatment group (Control: 48 segments, 25 patients). The change of lipid-rich plaque distribution between baseline and follow-up NIRS-IVUS was defined as the change of maximal lipid core burden index (LCBI) score for each of the 4-mm longitudinal segments (maxLCBI4mm).

Results

Mean duration from baseline to follow-up CAG was 239.4±52.4 days in the PCSK9i group and 341.0±84.1 days in the Control group (p<0.001). Despite the higher total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in the PCSK9i group at baseline (206.6±40.9 mg/dl vs. 168.5±37.1 mg/dl, 131.5±35.4 mg/dl vs. 100.0±29.5 mg/dl; respectively, p<0.001 for both), the PCSK9i group was significantly lower TC and LDL-C at the follow-up (111.5±23.5 mg/dl vs. 157.4±27.8 mg/dl, 40.8±15.7 mg/dl vs. 86.2±19.6 mg/dl; respectively, p<0.001 for both). Furthermore, the PCSK9i group induced greater regression of maxLCBI4mm than that of Control group (99.6±156.6 vs. 27.9±118.0, p=0.046) (Figure).

Figure 1

Conclusion

Compared with traditional statin therapy, PCSK9i treatment resulted in a greater decrease in lipid component in non-culprit coronary plaques. Therefore, PCSK9i may be useful option in preventing from adverse coronary events for the patients with CAD.

Feasibility and safety of jailed-pressure wire technique using durable optical fiber pressure wire for intervention of coronary bifurcation lesions

OBJECTIVES

The objective was to evaluate the safety, feasibility, and accuracy of the jailed-pressure wire technique using a durable optical fiber-based pressure wire with high-pressure dilatation using a non-compliant balloon after main vessel stenting.

BACKGROUND

Fractional flow reserve (FFR) information can help interventionists determine whether they should treat a jailed-side branch (SB). However, re-crossing a pressure wire into a jailed-SB is sometimes technically difficult.

METHODS

Fifty-one consecutive lesions from 48 patients who underwent the jailed-pressure wire technique were retrospectively investigated. The primary endpoint was complication rate and secondary endpoints included success rate of FFR measurement, incidence of wire disruption, and final drift rate. The usability of FFR for percutaneous coronary intervention of coronary bifurcation lesion was also evaluated.

RESULTS

Median age of the patients was 69 years and 80.4% were men. The most frequent underlying disease was stable angina (70.6%) and 68.6% were type B2 lesions. Our main findings were: the procedure was performed successfully in all cases without any complications or wire disruption, FFR could be measured without significant final drift in 95.9% of cases, and FFR measurements helped interventionists determine whether to perform a final kissing balloon dilatation in 49.0% cases.

CONCLUSIONS

The jailed-pressure wire technique using a durable optical fiber-based pressure wire with high-pressure post-dilatation maneuver was safe, feasible, and accurate.

Polymorphism and expression level of CYP51 (cytochrome P450) and sensitivity to ipconazole in Fusarium fujikuroi isolates

The relationship between the nucleotide sequences of CYP51, its expression level and its sensitivity to ipconazole of Fusarium fujikuroi isolates were investigated. Single nucleotide polymorphisms (SNPs) were observed in the CYP51 of isolates with different sensitivities to ipconazole, but no amino acid substitution was detected in the putative amino acid sequence of the CYP51 protein. On the other hand, the expression of CYP51 was enhanced by the presence of ipconazole, and it tended to be higher in isolates with lower sensitivities and no gibberellin productivity. In the presumed promoter region, the upstream nucleotide sequence of CYP51, several common SNPs and insertions of nucleotides were detected in the lower sensitivity isolates. These results suggest that F. fujikuroi isolates consist of 2 different groups in sensitivity and gibberellin productivity, and no amino acid substitution in CYP51 protein may contribute to the stably high efficacy of ipconazole against rice Bakanae disease for more than 25 years.

Reappraisal of classification of distal cholangiocarcinoma based on tumour depth

Background

In the eighth edition of the AJCC cancer staging classification, the T system for distal cholangiocarcinoma (DCC) has been revised from a layer-based to a depth-based approach. The aim of this study was to propose an optimal T classification using a measured depth in resectable DCC.

Methods

Patients who underwent pancreatoduodenectomy for DCC at 32 hospitals between 2001 and 2010 were included. The distance between the level of the naive bile duct and the deepest cancer cells was measured as depth of invasion (DOI). Invasive cancer foci were measured as invasive tumour thickness (ITT). Log rank χ2 scores were used to determine the cut-off points, and concordance index (C-index) to assess the survival discrimination of each T system.

Results

Among 404 patients, DOI was measurable in 182 (45·0 per cent) and ITT was measurable in all patients, with median values of 2·3 and 5·6 mm respectively. ITT showed a positive correlation with DOI (rs = 0·854, P &lt; 0·001), and the cut-off points for prognosis were 1, 5 and 10 mm. Median survival time was shorter with increased ITT: 12·4 years for ITT below 1 mm, 5·2 years for ITT at least 1 mm but less than 5 mm, 3·0 years for ITT at least 5 mm but less than 10 mm, and 1·5 years for ITT 10 mm or more (P &lt; 0·001). This classification exhibited more favourable prognostic discrimination than the T systems of the seventh and eighth editions of the AJCC (C-index 0·646, 0·622 and 0·624 respectively).

Conclusion

ITT is an accurate approach for depth assessment in DCC. The four-tier ITT classification with cut-off points of 1, 5 and 10 mm seems to be a better T system than those in the seventh and eighth editions of the AJCC classification.

Squamous cell carcinoma arising from lupus vulgaris with a >60-year history

We report the case of a 71-year-old Japanese man with squamous cell carcinoma arising from lupus vulgaris on the face, >60 years after the appearance of the lupus vulgaris. The red plaque on the patient's face had been diagnosed as a hemangioma or rosacea at several hospitals, although he had had lung tuberculosis at the age of 4 and his father died from lung tuberculosis at 38 years of age. Although lupus vulgaris was the most frequent clinical form of true skin tuberculosis until the 1960s, it has become rare since then. Malignant tumors are known to occur in individuals with lupus vulgaris, with a reported rate of 0.5-10.5%. In light of Japan's "graying society," tuberculosis is still an important disorder, and clinicians must remain aware of cutaneous tuberculosis.

Abstract P2-01-27: Sentinel lymph node biopsy by contrast-enhanced ultrasonography with sonazoid in patients with breast cancer - Prospective multicenter study

Background: The aim of this prospective study is to evaluate feasibility of the periareolar injection of contrast agent (Sonazoid (SNZ)) followed by ultrasonography (US) for identification of sentinel lymph node (SLN) in breast cancer patients with clinically negative node.

Patients and Methods: Patients with T1-2N0M0 breast cancer were recruited in this study. They received the periareolar injection of SNZ followed by US to identify contrast-enhanced SLN. Fine needle aspiration biopsy (FNAB) was done for each CE-SLN. Then, they underwent SLN biopsy with the conventional method, blue dye and/or radiotracer (B/R).

Results: In almost all cases, contrast-enhanced lymphatic vessels were clearly visualized US soon after the periareolar injection of SNZ, and SLN, into which lymphatic flow was draining, was easily identified. The identification rate of SLN was 98% (98/100) by SNZ and 100% (100/100) by B/R. The number of SLNs identified by SNZ (mean per patient, 1.52) was significantly (P &lt; 0.001) lower than that of those by B/R (2.22). Twenty-five patients had at least one metastasis in the SLNs identified by SNZ and/or B/R. In these patients, SLNs (n=39) identified by both SNZ and B/R showed a significantly (P &lt; 0.0001) higher positivity (74.4%) for metastases than those (n=19) identified by B/R alone (21.1%).

Conclusion: Identification of SLN by periareolar injection of SNZ followed by US is a technically easy method and the identification rate of SLN was as high as 98%, being comparable to the conventional B/R. SLNs detected by SNZ seem to represent the true SLNs which first receive lymphatic flow from the tumor among the SLNs detected by B/R.

Citation Format: Shimazu K, Ito T, Uji K, Miyake T, Motomura K, Noguchi S. Sentinel lymph node biopsy by contrast-enhanced ultrasonography with sonazoid in patients with breast cancer - Prospective multicenter study [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-01-27.

Identification of an orally active small-molecule PTHR1 agonist for the treatment of hypoparathyroidism

Parathyroid hormone (PTH) is essential for calcium homeostasis and its action is mediated by the PTH type 1 receptor (PTHR1), a class B G-protein-coupled receptor. Hypoparathyroidism and osteoporosis can be treated with PTH injections; however, no orally effective PTH analogue is available. Here we show that PCO371 is a novel, orally active small molecule that acts as a full agonist of PTHR1. PCO371 does not affect the PTH type 2 receptor (PTHR2), and analysis using PTHR1–PTHR2 chimeric receptors indicated that Proline 415 of PTHR1 is critical for PCO371-mediated PTHR1 activation. Oral administration of PCO371 to osteopenic rats provokes a significant increase in bone turnover with limited increase in bone mass. In hypocalcemic rats, PCO371 restores serum calcium levels without increasing urinary calcium, and with stronger and longer-lasting effects than PTH injections. These results strongly suggest that PCO371 can provide a new treatment option for PTH-related disorders, including hypoparathyroidism.

Hypoparathyroidism and osteoporosis can be treated with parathyroid hormone, but frequent injections are required. Here the authors develop a small-molecule agonist for the parathyroid hormone type I receptor that can be administered orally, and demonstrate its efficacy in rats.

Diabetic peripheral neuropathy and prevalence of erectile dysfunction in Japanese patients aged <65 years with type 2 diabetes mellitus: The Dogo Study

Only limited epidemiological evidence exists regarding the relationship between diabetic neuropathy and erectile dysfunction (ED) among Japanese patients with type 2 diabetes mellitus. To investigate the relationship between diabetic neuropathy and ED among Japanese patients with type 2 diabetes mellitus, a multicenter cross-sectional study was conducted in 287 male Japanese patients with type 2 diabetes mellitus, age (19-65 years). Diabetic neuropathy was diagnosed if the patients showed two or more of the following three characteristics: neuropathic symptoms, decreased or disappeared Achilles tendon reflex and/or abnormal vibration perception. ED, moderate to severe ED, and severe ED were defined as present when a subject had a Sexual Health Inventory for Men score <22, <12 and <8, respectively. The prevalence values of diabetic neuropathy and severe ED were 47.0 and 39.0%, respectively. Diabetic neuropathy was independently positively associated with severe ED, but not ED and moderate ED: the adjusted odds ratio was 1.90 (95% confidence interval: 1.08-3.38). No relationships were found between diabetic retinopathy or diabetic nephropathy and ED. Diabetic neuropathy is positively associated with severe erectile dysfunction among Japanese type 2 diabetes mellitus patients aged <65 years.

Fish collagen is an important panallergen in the Japanese population

Collagen was identified as a fish allergen in early 2000s. Although its allergenic potential has been suggested to be low, risks associated with collagen as a fish allergen have not been evaluated to a greater extent. In this study, we aimed to clarify the importance of collagen as a fish allergen. Our results showed that 50% of Japanese patients with fish allergy had immunoglobulin E (IgE) against mackerel collagen, whereas 44% had IgE against mackerel parvalbumin. IgE inhibition assay revealed high cross-reactivity of mackerel collagen to 22 fish species (inhibition rates: 87-98%). Furthermore, a recently developed allergy test demonstrated that collagen triggered IgE cross-linking on mast cells. These data indicate that fish collagen is an important and very common panallergen in fish consumed in Japan. The high rate of individuals' collagen allergy may be attributable to the traditional Japanese custom of raw fish consumption.

Estimated pulmonary capillary wedge pressure assessed by speckle tracking echocardiography predicts successful ablation in paroxysmal atrial fibrillation

Background

Atrial fibrillation (AF) is associated with left atrial (LA) remodeling caused by pressure and/or volume (LAV) overload. Increased pulmonary capillary wedge pressure (PCWP) represents LA pressure overload. We recently reported that pulmonary capillary wedge pressure (ePCWP) can be estimated by the kinetics-tracking (KT) index that combines LA function and volume using speckle tracking echocardiography (STE), and has a strong correlation with PCWP measured by right heart catheterization (r = 0.92). Therefore, we hypothesized that ePCWP is the best echocardiographic predictor of successful AF ablation.

Methods

We enrolled 137 patients with paroxysmal AF (age: 61 ± 10 years) who underwent pulmonary vein isolation. We measured LAV index, LA emptying function (EF) and LA stiffness during sinus rhythm before ablation using STE. PCWP was noninvasively estimated by STE as we previously reported. Parameters were compared between a group with AF recurrence (n = 30, age: 59 ± 11 years) and a group with successful ablation (sinus rhythm maintained for >1 year) (n = 107, age 61 ± 11 years).

Results

The ePCWP was correlated with PCWP measured by right heart catheterization (r = 0.76, p < 0.01). Compared with the non-recurrence group (n = 107, age: 61 ± 11), the AF recurrence group had significantly increased ePCWP (10.6 ± 3.5 vs 14.6 ± 2.9 mmHg, p < 0.01), minimum LAV index (29 ± 12 ml/m² vs 37 ± 14 ml/m², p < 0.01) and LA stiffness (0.47 ± 0.33 vs 0.83 ± 0.59, p < 0.01), but lower total LA EF (44 ± 11 % vs 39 ± 13 %, p < 0.01) before ablation. In multivariate logistic regression analysis, ePCWP was the most significant independent predictor of successful ablation. Using 13 mmHg of PCWP as the optimal cutoff value, the sensitivity and specificity for successful ablation were 73 and 77 % (area under the curve = 0.81), respectively.

Conclusion

The ePCWP that is measured by the combination of LA function and volume before ablation was a better predictor of the successful ablation compared with LA function and volume separately. The ePCWP estimated by STE is useful to predict the successful ablation in paroxysmal AF, and could be useful to improve candidate selection for AF ablation.

Noninvasive estimation of pulmonary capillary wedge pressure in patients with mitral regurgitation: A speckle tracking echocardiography study

BACKGROUND

Echocardiographic parameters to predict pulmonary capillary wedge pressure (PCWP) in mitral regurgitation (MR) are not yet elucidated. We reported that PCWP could be accurately estimated by novel KT index which is defined as log10[left atrial (LA) emptying function (EF)/LA volume]. We examined the usefulness of the KT index as a predictor of PCWP in primary and secondary MR with sinus rhythm and also MR with atrial fibrillation.

METHODS

LA dimension, strain, volume, EF, and E/e' were measured in moderate to severe MR with sinus rhythm (n=58, age: 67±8 years) and MR with atrial fibrillation (n=24, age: 69±11 years) just before catheterization and in normal subjects (n=26, age: 67±11 years) using speckle tracking echocardiography. MR with sinus rhythm was divided into primary MR (n=27) and secondary MR (n=31). The estimated PCWP (ePCWP) was calculated as 10.8-12.4×KT index.

RESULTS

There was a correlation between PCWP and LA dimension, E/e', minimum LA volume index, active LAEF, total LAEF, or LA strain (r=0.32, r=0.31, r=0.55, r=-0.61, r=-0.51, and r=-0.50, respectively, p<0.05). The better correlation was found between PCWP and ePCWP in MR including both primary and secondary MR and also MR with atrial fibrillation (r=0.70, r=0.67, and r=0.58, respectively, p<0.01). Multiple regression analysis revealed that ePCWP was an independent predictor of PCWP in MR. The ePCWP demonstrated good diagnostic accuracy (area under the curve of 0.86) and sensitivity (81%) and specificity (71%) to predict elevated PCWP >15mmHg using a cut-off of 16mmHg.

CONCLUSION

The ePCWP was the reliable echocardiographic parameter to predict PCWP in primary and secondary MR and might also be useful in MR with atrial fibrillation. The ePCWP may have an incremental value in a clinical setting.

A genome-wide scan for tying-up syndrome in Japanese Thoroughbreds

Tying-up syndrome, also known as recurrent exertional rhabdomyolysis in Thoroughbreds, is a common muscle disorder for racehorses. In this study, we performed a multipoint linkage analysis using LOKI based on the Bayesian Markov chain Monte Carlo method using 5 half-sib families (51 affected and 277 nonaffected horses in total), and a genome-wide association study (GWAS) using microsatellites (144 affected and 144 nonaffected horses) to map candidate regions for tying-up syndrome in Japanese Thoroughbreds. The linkage analysis identified one strong L-score (82.45) between the loci UCDEQ411 and COR058 (24.9-27.9 Mb) on ECA12. The GWAS identified two suggestive genomic regions on ECA12 (24.9-27.8 Mb) and ECA20 (29.3-33.5 Mb). Based on both results, the genomic region between UCDEQ411 and TKY499 (24.9-27.8 Mb) on ECA12 was the most significant and was considered as a candidate region for tying-up syndrome in Japanese Thoroughbreds.

FT-NMR Detection of 45Sc, 49Ti and 93Nb in TiO2 Single Crystal

In order to determine the electric quadrupole moment of the short-lived β-emitter 41Sc from the quadrupole coupling constant in TiO2 , we measured the field gradient by detecting the Fourier-Transformed-NMR of stable isotope 45Sc doped in TiO2. Also, in order to study the electronic structure of impurities systematically, EFGs were measured for 45Sc, 49Ti and 93Nb in a TiO2 ingle single crystal.

Electric Quadrupole Interactions of the Short-Lived β-Emitter 12N in Insulator Crystals (12N Implanted in Single Crystal TiO2)

The electronic structure of nitrogen atoms as impurities in an ionic TiO2 crystal has been investigated by analyzing electric field gradients (EFGs) measured by use of short-lived β-emitting 12N implant-ed following nuclear reactions. Conventional β-NMR and its modification, suitable for the detection of quadrupole effects in the NMR spectra, were used for the investigation of hyperfine interactions of 12N located in substitutional sites of O atoms and interstitial sites in the crystal. In order to deduce absolute values of the EFGs from the obtained eqQ/h, the quadrupole moment of 12N has been determined from the NMR detection of 12N implanted in BN(hexagonal) crystal. Here the EFG at the N atom in BN was measured by detecting the FT-NMR of 14N in the crystal. The EFGs in TiO2 are compared with the theoretical predictions based on the ab initio band-structure calculation in the framework of the KKR method.

Hyperthermic intraperitoneal chemotherapy using a combination of mitomycin C,5-fluorouracil, and oxaliplatin in patients at high risk of colorectal peritoneal metastasis: A Phase I clinical study

INTRODUCTION

The drugs and protocols used for hyperthermic intraperitoneal chemotherapy (HIPEC) vary among institutions. Here we show the efficacy of the 3-drug combination of mitomycin C (MMC), 5-fluorouracil (5FU), and oxaliplatin (OHP) in an in vitro simulation of HIPEC and the safety of HIPEC with these drugs during a Phase I study of patients at high risk of developing colorectal peritoneal metastasis.

METHODS

To simulate HIPEC, we used HCT116 and WiDr cells to assess the growth inhibitory efficacy of MMC 2 μg/mL, 5FU 200 μg/mL, and OHP 40 μg/mL as single drugs or their combination after an exposure time of 30 min at 37 or 42 °C. In addition, nine patients underwent surgical resection of tumors and HIPEC with MMC, 5FU, and an escalating dose of OHP (90/110/130 mg/m²). Dose-limiting toxicity was monitored.

RESULTS

In the simulation, the 3-drug combination showed marked tumor-suppressive effects compared with those from ten times higher dose of OHP 400 μg/mL, with significant augmentation under hyperthermic conditions. No dose-limiting toxicity occurred in the clinical study. Dose escalation was completed at the final level of OHP.

CONCLUSIONS

The MMC-5FU-OHP combination showed marked growth inhibition against colorectal cancer cells under hyperthermic conditions in vitro. In the phase I study, the recommended dose of OHP was determined as 130 mg/m² when used with MMC and 5FU; HIPEC using MMC-5FU-OHP appears to be safe and feasible for patients at high risk of colorectal peritoneal metastasis.