Abstract OT2-07-05: A phase III trial to compare eribulin mesylate + trastuzumab (H) + pertuzumab (P) with paclitaxel or docetaxel + HP for HER2-positive advanced or metastatic breast cancer (JBCRG-M06/ EMERALD)

Background: Docetaxel + Trastuzumab (H) + Pertuzumab (P) provided progression-free survival (PFS) and overall survival (OS) benefits in HER2-positive advanced or metastatic breast cancer (AMBC) in the CLEOPATRA study as a first-line therapy. However, long-term administration of docetaxel at a dose of 75 mg/m2 every 3 weeks in AMBC patients (pts) is difficult due to the toxicities. Eribulin mesylate (E) is a well-tolerated microtubule inhibitor, and we have reported the efficacy and safety of EHP regimen as first- and second-line therapy for AMBC in a multicenter, phase II study (JBCRG-M03/UMIN000012232). In this M06 study, we address the clinical question as to which is the better chemotherapy partner for HP as first line regimen, in terms of efficacy, toxicity and QOL.

Methods: JBCRG-M06 is a multicenter open-label randomized phase III study for HER2-positive AMBC pts who have received no prior chemotherapy except for the HER2- Antibody-Drug Conjugate (ADC). Pts will be randomized 1:1 to E (1.4mg/m2 on day 1 and 8) + H (8 mg/kg loading dose followed by 6 mg/kg) +P (840 mg loading dose followed by 420 mg) q3wks or standard taxanes (docetaxel 75mg/m2 on day1 or paclitaxel 80mg/m2 on day 1, 8 and 15) + HP q3wks. Stratification factors for randomization are; presence of visceral metastases, number of prior taxanes on perioperative adjuvant treatment, and treatment with prior anti-HER2-ADC. Primary endpoint is PFS and secondary endpoints include overall response rate, duration of response, OS, patient-reported outcomes (PRO) relating to QOL and peripheral neuropathy, new-metastases free survival, and safety. Translational research to search for biomarker for individual precision therapy will be performed. Main eligibility criteria are as follows: pts with HER2-positive AMBC, female aged 20-70 years old, ECOG PS of 0-1, LVEF ≥ 50% at baseline and adequate organ function. Pts who had progressive MBC within 6 months after the end of primary adjuvant systemic chemotherapy are excluded. The sample size was calculated by type1 error (2-sided) of 0.05 and 80% power to estimate the noninferiority margin 1.33 with an expected median PFS of 14.2 months. The target number of pts is 480 recruited over the duration of 3-years. The first patient in was achieved on August 2017. (ClinicalTrials.gov Identifier:NCT03264547).

Citation Format: Masuda N, Yamashita T, Saji S, Araki K, Ito Y, Takano T, Takahashi M, Tsurutani J, Koizumi K, Kitada M, Kojima Y, Sagara Y, Tada H, Iwasa T, Kadoya T, Iwatani T, Hasegawa H, Morita S, Ohno S. A phase III trial to compare eribulin mesylate + trastuzumab (H) + pertuzumab (P) with paclitaxel or docetaxel + HP for HER2-positive advanced or metastatic breast cancer (JBCRG-M06/ EMERALD) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-07-05.

Simultaneous analysis of major ingredients of Gardenia fruit by HPLC-MS/TQMS method

An efficient, accurate HPLC-MS/TQMS method was introduced for the quantitative/qualitative simultaneous analysis of main ingredients, namely geniposide and genipingentiobioside, in the Gardenia fruit. The separation was successfully obtained using a C8 (100mm×2.1mm, 5μm, 30°C) column by gradient elution with ultrapure water as mobile phase, where flow rate was set to 0.2 ml/min and detection wavelength at 240 nm. The analytical method was validated and the quantification of active compounds, namely genipingentiobioside and gardenoside, was performed. Linearity, precision, repeatability, stability and recovery were also reported. The quantitative analysis revealed that both main ingredients as geniposide and genipingentiobioside have performed a good linear relationship in 0.1-100 mg/ml concentration range (r=1.00000 and r =0.99998). The average content was measured to be 4.842% with RSD 0.96% for geniposide and 1.1976% with RSD 0.47% for genipingentiobioside in the Gardenia fruit. Accordingly, this method would be feasible for the quantity and quality control of crude drugs.

Clinical application of amplicon-based next-generation sequencing to therapeutic decision making in lung cancer

BACKGROUND

The clinical implementation of genomic profiling for lung cancer with high-throughput, multiplex tests is warranted to allow prioritization of appropriate therapies for individual patients. We have now applied such testing to detect actionable mutations that may inform treatment recommendations in lung cancer.

PATIENTS AND METHODS

We prospectively applied amplicon sequencing panels that cover both mutational hotspots in 22 genes related to lung and colon tumorigenesis as well as 72 major variants of ALK, RET, ROS1, and NTRK1 fusion transcripts. We then determined the proportion of patients who received genotype-directed therapy and their overall survival (OS).

RESULTS

Tumor specimens from 110 patients with lung cancer recruited between July 2013 and March 2015 were analyzed. The most common genetic alterations were TP53 mutations in 42 patients, followed by EGFR mutations in 25, STK11 mutations in 12, and KRAS mutations in 10. Potentially actionable mutations were identified in 44 patients including 50% of those with adenocarcinoma and 14% of those with squamous cell carcinoma. The OS of patients with advanced or recurrent cancer who had an actionable mutation and received targeted therapy (median OS not achieved) was significantly longer than that of those with no mutation (18.1 months, P = 0.041) or of those with a mutation not so treated (6.1 months, P = 0.0027).

CONCLUSIONS

Multiplex genomic testing was performed on formalin-fixed, paraffin-embedded tumor specimens with a success rate of ≥95%. Such testing can assist physicians in matching patients with approved or experimental targeted treatments.

CLINICAL TRIAL REGISTRATION

The University Medical Hospital Information Network (UMIN) Clinical Trials Registry under the identifier UMIN000014782.

A phase I dose-escalation study of eribulin and S-1 for metastatic breast cancer

Background:

We evaluated the safety, maximum-tolerated dose (MTD), pharmacokinetics, recommended dose for phase II (P2RD), and preliminary anticancer activity of a combination eribulin and S-1 therapeutic in metastatic breast cancer patients pretreated with anthracycline and taxane.

Method:

Patients aged 20–74 years were recruited. In level 1, patients received S-1 (65 mg m⁻²) from day 1 to 14, and eribulin (1.1 mg m⁻²) on day 1 and 8 in a 21-day cycle. In level 2, eribulin was increased to 1.4 mg m⁻². In level 3, S-1 was increased to 80 mg m⁻².

Results:

Twelve patients were enrolled into three cohorts. Planned dose escalation was completed, with one case exhibiting dose-limiting toxicity (grade 3 hypokalaemia) at level 3, without reaching the MTD. The P2RD was determined to be level 2 (eribulin 1.4 mg m⁻² and S-1 65 mg m⁻²). The most common grade 3 or 4 toxicity was neutropenia (83.3%), followed by febrile neutropenia (25.0%). Five of eleven patients (41.7%) with measurable disease had a partial response. Pharmacokinetics were characterised by dose-dependent elimination and nonlinear exposure.

Conclusion:

Dose level 3 was not tolerated owing to febrile neutropenia development. Thus, intermediate dose level 2 was recommended for further evaluation. Preliminary antitumour activity warrants further investigation in this setting.

Site-specific changes in cytokine response to septic dose of lipopolysaccharide in ovariectomized female rats

PURPOSE

The immune response is altered according to hormonal and metabolic status. Obesity increases the inflammatory and fever response, whereas loss of gonadal steroid decreases behavioral response to immune stress. However, the immune systems of ovariectomized animals exhibiting obesity and gonadal steroid deficiency, particularly under septic conditions, have not been fully examined. In the present study, we evaluated the ovariectomy-induced changes of central and peripheral immune responses to life-threatening septic stimulus.

METHODS AND RESULTS

Ovariectomized rats showed heavier body weight and lighter uterine weight when compared with gonadally intact rats. Fever response to septic dose of lipopolysaccharide (LPS) in ovariectomized rats was less evident when compared with that in gonadally intact rats. In addition, under LPS-injected septic conditions, hypothalamic gene levels of Interleukin-1β (IL-1β), Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) and serum protein levels of IL-1β and TNF-α in ovariectomized rats were lower than those in gonadally intact rats. On the other hand, IL-6 levels in visceral fat under septic conditions were higher in ovariectomized rats than in gonadally intact rats.

CONCLUSIONS

These findings indicate that ovariectomy-induced site-specific changes in cytokine response under septic conditions. As hypothalamic, but not peripheral, pro-inflammatory cytokines are directly involved in the fever response, the attenuation of fever response observed in ovariectomized rats may be caused by a reduction in central cytokine responses.

Abstract P3-13-08: A phase I study of weekly nab-paclitaxel in combination with S-1 in patients with metastatic breast cancer

Background: S-1 is an oral, fixed dose combination product comprised of tegafur, a fluoropyrimidine prodrug of 5-fluorouracil (5-FU), and modulators of 5-FU metabolism, 5-chloro-2.4-dihydrooxypyridine and oteracil potassium. S-1 is designed to provide oral delivery of 5-FU, a pyrimidine analog antimetabolite antineoplastic agent, while reducing the rate of degradation of 5-FU and its conversion in the gastrointestinal tract to its toxic phosphorylated metabolite. S-1 is active in breast cancer and a variety of solid tumors. nab™-Paclitaxel (nab-P) is a treatment option in metastatic breast cancer (MBC) (approved 260 mg/m2 q3w dosing schedule), and high activity of nab-P with single-agent weekly administration at 100 mg/m2 has been investigated in MBC as well as other disease states. Since these two agents differed in their mechanisms of action and toxicity profiles, we sought to test their combined activity in a phase I study of nab-P/S-1 for HER2-negative MBC. The primary objectives of this study was to determine the maximum tolerated dose (MTD) and recommended dose (RD) of nab-P/S-1 in patients with HER-2 negative MBC. The secondary objective of this study was to evaluate pharmacokinetic (PK) parameters of both agents.

Methods: Patients received treatment on 3 week cycles. S-1 was administered orally at a twice-daily dose of 65 mg/m2 (dose level 1 and 2b) or 80 mg/m2 (dose level 2a and 3) for 14 days and nab-P was administered as a 30-minute IV infusion at a dose of 100 mg/m2 on days 1 and 8 (dose level 1 and 2b) or 100 mg/m2 on days 1, 8 and 15 (dose level 2a and 3).

Results: Fifteen patients were enrolled in this study; nab-P/S-1 was given as first-line chemotherapy for MBC in 9 patients, and as second-line therapy subsequent to an anthracycline-containing therapy in 6 patients. At dose level 3, one patient experienced a DLT. The observed DLT was delay of initiation of next cycle, G4 neutropenia had not recovered to G1/G0 in a period defined on the protocol. No cases of febrile neutropenia were observed. Judged from the status of dose reduction and the extension of drug holidays (cycle start delay), and the occurrence of non-severe adverse events after 2 cycles, the dose level was not increased above level 3. Seven patients were able to be treated 10 cycles or more. Additionally, three patients were able to be treated 20 cycles or more. Among of the 12 patients who had a measurable lesion which was evaluable by RECISTv1.1, the overall response rate was 50%, with 1 CR, 5 PR, 4 SD, and 1 PD. Pharmacokinetics of Paclitaxel and 5-FU in the combination therapy were comparable to those after single-agent administration of nab-P and S-1, respectively.

Conclusion: Based on the results of this study, the RD was determined to be dose level 3 (S-1 80 mg/m2 twice daily plus nab-P 100 mg/m2 on days 1, 8, and 15). Since this combination therapy was generally well tolerated even with prolonged treatment, it is suggested that this combination therapy may be a promising treatment regimen in HER-2 negative MBC and merits further evaluation.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-13-08.

Ovarian torsion associated with cessation of hormonal treatment for polycystic ovarian syndrome: a case report

Torsion of an ovary or fallopian tube (adnexal torsion) usually occurs in ovaries with tumors or functional cysts. In polycystic ovarian syndrome (PCOS), the ovaries are bilaterally enlarged, but these enlarged ovaries rarely twist. Recently, the authors encountered a PCOS patient with ovarian torsion after the cessation of Kaufmann treatment. The etiological factors were unclear, but the authors suggest that the increase in ovarian volume was due to transient hypergonadotropic feedback. Thus, more attention should be paid to adnexal torsion that may arise subsequent to transient hypergonadtropic states, in relation to the cessation of hormonal treatment, and enlarged ovaries in PCOS patients.

Amniocentesis can be useful during the third trimester of pregnancy for antenatal diagnosis of Pallister-Killian syndrome: a case report

Pallister-Killian syndrome (PKS) is an extremely rare genetic disease characterized cytogenetically by tetrasomy 12p mosaicism. We recently encountered a case of maternal hydramnios associated with congenital diaphragm hernia according to the prenatal diagnosis. Prenatal diagnosis revealed a non-mosaic 47, XY, i(12)(p10) karyotype at amniocentesis of G-band and M-FISH analysis. We performed chromosomal analysis in both interphase and metaphase cells from a cord blood lymphocyte specimen. Mosaic tetrasomy of chromosome 12p was supported by G-banding or FISH analysis. When fetal observations are performed in detail using 2D/3D US, PKS may be diagnosed. In addition, it is effective to perform amniocentesis during the third trimester of pregnancy.

Multiple ulcers in the small and large intestines occurred during tocilizumab therapy for rheumatoid arthritis

Tocilizumab is a monoclonal antibody against human interleukin-6 receptor which blocks the binding of interleukin-6 to its receptor. Tocilizumab is effective for the treatment of inflammatory disorders including rheumatoid arthritis. We report a case of multiple ulcers in the small and large intestines, which occurred during tocilizumab therapy. A 57-year-old woman started to use tocilizumab for rheumatoid arthritis. Three months later, she complained of hematochezia. Double-balloon endoscopy revealed multiple small aphthoid ulcers in the small and large intestines. One month after the woman had recovered, she was given tocilizumab again. The woman had hematochezia and abdominal pain again 2 weeks later. Colonoscopy revealed multiple round, discrete punched-out ulcers in the terminal ileum, and vast deep ulcers from the cecum to the descending colon. Bioptic histopathology and cultivation showed non-specific findings. Six weeks after discontinuation of tocilizumab, ulcers in the small and large intestine dramatically improved, leaving ulcer scars. This disease course and the results of examination made us strongly suspect that tocilizumab induced multiple ulcers in the small and large intestines. Interleukin-6 is a pleiotropic cytokine and involved in intestinal mucosal wound healing as well as in inflammatory processes. It is possible that tocilizumab inhibited tissue repair of the intestine and caused intestinal ulcers.

Marked anti-tumour activity of the combination of YM155, a novel survivin suppressant, and platinum-based drugs

BACKGROUND

Survivin, a member of the inhibitor of apoptosis protein family, is an attractive target for cancer therapy. We have now investigated the effects of the combination of YM155, a novel small-molecule inhibitor of survivin expression, and platinum compounds (cisplatin and carboplatin) on human non-small cell lung cancer (NSCLC) cell lines.

METHODS

The anti-cancer efficacy of YM155 in combination with platinum compounds was evaluated on the basis of cell death and progression of tumour xenografts. Platinum compound-induced DNA damage was evaluated by immunofluorescence analysis of histone gamma-H2AX.

RESULTS

Immunofluorescence analysis of histone gamma-H2AX showed that YM155 delayed the repair of double-strand breaks induced in nuclear DNA by platinum compounds. The combination of YM155 and platinum compounds also induced synergistic increases both in the number of apoptotic cells and in the activity of caspase-3. Finally, combination therapy with YM155 and platinum compounds delayed the growth of NSCLC tumour xenografts in nude mice to an extent greater than that apparent with either treatment modality alone.

CONCLUSION

These results suggest that YM155 sensitises tumour cells to platinum compounds both in vitro and in vivo, and that this effect is likely attributable to the inhibition of DNA repair and consequent enhancement of apoptosis.

Effects of intrauterine undernutrition on hypothalamic Kiss1 expression and the timing of puberty in female rats

Recent studies have suggested that intrauterine undernutrition is closely associated with the pathogenesis of diseases after birth. Perinatal undernutrition is known to disturb the development of reproductive function and delay the onset of puberty in some species. Using a rat model, we determined the effects of prenatal undernutrition on the development of the hypothalamic kisspeptin system and evaluated whether the alteration of the kisspeptin system contributes to the delayed onset of puberty induced by prenatal undernutrition. We also evaluated the effects of prenatal undernutrition on the developmental changes in serum leptin levels because leptin was a putative positive regulator of the hypothalamic kisspeptin system. We compared the timing of vaginal opening (VO) and the developmental changes in body weight, hypothalamic Kiss1 mRNA levels, and serum leptin concentrations between offspring with prenatal undernutrition (UN offspring) and normal nutrition (NN offspring). After birth, the UN offspring showed rapid growth and had caught up to body weight of the NN offspring by postnatal day 12. After postnatal day 16, the UN offspring showed significantly lower Kiss1 mRNA levels than the NN offspring, despite their significantly higher serum leptin levels (at days 20 and 28). The timing of VO in the UN offspring was delayed compared with that in the NN offspring, and chronic central injection of kisspeptin normalized the timing of VO in the UN offspring. These results suggest that decreased hypothalamic kisspeptin action contributes to the delayed onset of puberty in prenatally undernourished female rats. Increased leptin resistance in the kisspeptin system might be involved in these alterations.

Decreased expression of kisspeptin mediates acute immune/inflammatory stress-induced suppression of gonadotropin secretion in female rat

Kisspeptin and its corresponding receptor, the G protein-coupled receptor 54, play an important role in reproductive systems. It has been suggested that reproductive disorders in metabolically disrupted animals are caused by the alteration of hypothalamic KiSS-1 systems. Immune/inflammatory challenge is also known to disrupt reproductive function. However, the effects of immune/inflammatory challenge on KiSS-1 systems have not been investigated. In this study, we showed that lipopolysaccharide (LPS) injection decreased hypothalamic KiSS-1 mRNA expression as well as plasma LH levels in ovariectomized rats. Indomethacin completely blocked the suppressive effects of LPS on LH secretion and KiSS-1 mRNA level. Furthermore, we showed that i.v. injection of kisspeptin increased plasma LH levels in LPS-administrated rats to the same degree as in saline-injected rats. These results suggest that KiSS-1 systems are sensitive to immune/inflammatory challenge conditions and transmit these signals into the central reproductive system.

A case of maxillary duplication with a soft palate reconstruction using a forearm flap

Maxillary duplication is a rare congenital anomaly that occurs in the jaw/mouth area. It is generally regarded as sporadic in nature. Total or subtotal soft palate reconstruction for oropharyngeal defects, which include post-surgical and congenital defects, presents a difficult surgical challenge. A maxillary duplication in which the soft palate is reconstructed using a vascularized forearm flap is described. The velopharyngeal insufficiency in the present case is caused by the almost complete deficiency of the soft palate, suggesting that a conventional pharyngeal flap operation with localized mucosal myocutaneous flaps would not produce favorable results in terms of postoperative contractions in the pharyngeal flaps. In such cases, the reconstruction of the soft palate using vascularized free forearm flaps, guided by flexibility regarding the size and adequate thickness of the flaps, may be useful.

Enhancement of the antitumor activity of ionising radiation by nimotuzumab, a humanised monoclonal antibody to the epidermal growth factor receptor, in non-small cell lung cancer cell lines of differing epidermal growth factor receptor status

The expression and activity of the epidermal growth factor receptor (EGFR) are determinants of radiosensitivity in several tumour types, including non-small cell lung cancer (NSCLC). However, little is known of whether genetic alterations of EGFR in NSCLC cells affect the therapeutic response to monoclonal antibodies (mAbs) to EGFR in combination with radiation. We examined the effects of nimotuzumab, a humanised mAb to EGFR, in combination with ionising radiation on human NSCLC cell lines of differing EGFR status. Flow cytometry revealed that H292 and Ma-1 cells expressed high and moderate levels of EGFR on the cell surface, respectively, whereas H460, H1299, and H1975 cells showed a low level of surface EGFR expression. Immunoblot analysis revealed that EGFR phosphorylation was inhibited by nimotuzumab in H292 and Ma-1 cells but not in H460, H1299, or H1975 cells. Nimotuzumab augmented the cytotoxic effect of radiation in H292 and Ma-1 cells in a clonogenic assay in vitro, with a dose enhancement factor of 1.5 and 1.3, respectively. It also enhanced the antitumor effect of radiation on H292 and Ma-1 cell xenografts in nude mice, with an enhancement factor of 1.3 and 4.0, respectively. Nimotuzumab did not affect the radioresponse of H460 cells in vitro or in vivo. Nimotuzumab enhanced the antitumor efficacy of radiation in certain human NSCLC cell lines in vitro and in vivo. This effect may be related to the level of EGFR expression on the cell surface rather than to EGFR mutation.

The type 2 corticotrophin-releasing hormone receptor mediates orexin A-induced luteinising hormone suppression in ovariectomised rats

Orexins are thought to be regulatory factors of the arousal and sleep patterns. They also affect immune, feeding, autonomic and neuroendocrine systems. We have previously shown that intracerebroventricular (i.c.v.) injection of orexin decreases pulsatile luteinising hormone (LH) secretion in ovariectomised (OVX) rats. However, the details of this mechanism have not been fully examined. Intracerebroventricular injection of orexin A also stimulates corticotrophin-releasing hormone (CRH) systems, which have been implicated in the stress-induced suppression of reproductive function. In the present study, we investigated the role of CRH systems in orexin-induced LH suppression. OVX rats were implanted with i.c.v. and intravenous (i.v.) cannulae. After i.c.v. injection of orexin and/or CRH receptor antagonists, blood samples were collected through the i.v. cannula at 6-min intervals for 120 min for LH measurement. Intracerebroventricular injection of orexin A or B (3 nmol/2.5 microl) suppressed pulsatile LH secretion. Coadministration of orexin A and alpha-helical corticotrophic-releasing factor (CRF), a nonselective CRH receptor antagonist (13 nmol/2.5 microl), or astressin(2)B, a selective type2 (CRH-R2) CRH receptor antagonist (28 nmol/2.5 microl), partly restored pulsatile LH secretion. Orexin B-induced LH suppression was not restored by alpha-helical CRF. In addition, i.c.v. injection of orexin A increased CRH and urocortin II (UcnII), but not Ucn mRNA levels, in the hypothalamus. These findings suggest that CRH-R2 mediates orexin A-induced LH suppression and it is possible that CRH and UcnII in the hypothalamus are involved in this pathway.

The novel microtubule-interfering agent TZT-1027 enhances the anticancer effect of radiation in vitro and in vivo

TZT-1027 is a novel anticancer agent that inhibits microtubule polymerisation and manifests potent antitumour activity in preclinical models. We have examined the effect of TZT-1027 on cell cycle progression as well as the anticancer activity of this drug both in vitro and in vivo. With the use of tsFT210 cells, which express a temperature-sensitive mutant of Cdc2, we found that TZT-1027 arrests cell cycle progression in mitosis, the phase of the cell cycle most sensitive to radiation. A clonogenic assay indeed revealed that TZT-1027 increased the sensitivity of H460 cells to gamma-radiation, with a dose enhancement factor of 1.2. Furthermore, TZT-1027 increased the radiosensitivity of H460 and A549 cells in nude mice, as revealed by a marked delay in tumour growth and an enhancement factor of 3.0 and 2.2, respectively. TZT-1027 also potentiated the induction of apoptosis in H460 cells by radiation both in vitro and in vivo. Histological evaluation of H460 tumours revealed that TZT-1027 induced morphological damage to the vascular endothelium followed by extensive central tumour necrosis. Our results thus suggest that TZT-1027 enhances the antitumour effect of ionising radiation, and that this action is attributable in part to potentiation of apoptosis induction and to an antivascular effect. Combined treatment with TZT-1027 and radiation therefore warrants investigation in clinical trials as a potential anticancer strategy.

[Successful resection of left ventricular myxoma in a toddler; report of a case]

A 4-year-old girl was found to have large left ventricular myxoma without any tumor-related symptoms. She underwent an urgent surgery and the myxoma was successfully removed through a left ventriculectomy. Great care was taken to prevent tumor-embolization during surgery, and to resect the endocardium attaching directly to the tumor. Future surveillance of this case warrants our operative technique described in this report.

An in vitro interethnic comparison of monoamine oxidase activities between Japanese and Caucasian livers using rizatriptan, a serotonin receptor 1B/1D agonist, as a model drug

AIMS

Monoamine oxidase (MAO) is located in human liver, and catalyses the oxidative deamination step of many xenobiotics. However, whether there exists an interethnic difference in MAO activities has, to our knowledge, not been clarified. We aimed to assess the MAO type A (MAO-A) involvement in the metabolic pathway of rizatriptan (RIZ), an antimigraine 5-hydroxytryptamine (5-HT)1B/1D agonist, and the interethnic difference in MAO activities between Caucasians and Japanese using RIZ as a model drug in in vitro experiments.

METHODS

Oxidative deaminase activities were determined with the subcellular fractions of Japanese livers and the microsomal fraction of Caucasian livers using RIZ, 5-HT (MAO-A substrate) and 2-phenylethylamine (PEA) (MAO-B substrate) as substrates.

RESULTS

The oxidative deaminase activities of RIZ vs. 5-HT were highly (r = 0.87 and 0.96, P < 0.001) correlated with each other in both the microsomal and mitochondrial fractions of Japanese livers. Subsequent results were obtained from in vitro experiments using liver microsomes based upon these findings. The oxidative deaminase activities of RIZ were inhibited completely by the nanomolar-order concentration of clorgyline and Ro 41-1049 (MAO-A selective inhibitors), but not by that of Ro 16-6491 (MAO-B selective inhibitor). The majority of the mean Michaelis-Menten values for three substrates toward MAO obtained from six Japanese and six Caucasian liver microsomes reached no significant differences between the two ethnic groups. The mean microsomal oxidative deaminase activities assessed in 18 Japanese and 20 Caucasian livers using the three substrates also showed no significant differences between the two ethnic groups.

CONCLUSIONS

RIZ is mainly metabolized by MAO-A and the in vitro oxidative deaminase activities mediated via MAO-A and -B do not appear to differ between Japanese and Caucasians.

Molecular cloning of Bombyx cerebral opsin (Boceropsin) and cellular localization of its expression in the silkworm brain

We have cloned a cDNA for a novel opsin from the larval brain of the silkworm Bombyx mori in which the photoperiodic photoreceptor had been supposed to reside in the cephalic central nervous system (CNS). Its deduced amino acid sequence was composed of 381 amino acids and included amino acid residues highly conserved in insect visual pigments. This opsin belonged to the long wavelength photoreceptor group of insect opsins and showed the greatest degree of homology (84%) with the green visual photoreceptor in the sphingid moth. We have designated this Bombyx cerebral opsin as Boceropsin. Southern blotting experiments indicated that the Boceropsin gene is present in a single copy, and RT-PCR analysis revealed that Boceropsin mRNA is expressed in the larval brain but not in the subesophageal ganglion (Sg) or thoracic ganglion (Tg). Immunohistochemical analyses demonstrated that Boceropsin protein is present bilaterally in some defined cells localized in the brain of Bombyx larvae. This is the first report of expression of an opsin-based protein in CNS of an insect. The possibility that the Boceropsin functions as the photoperiodic receptive pigment in the silkworm is also discussed.

Formation of PCDDs and PCDFs during the combustion of polyvinylidene chloride

In laboratory-scale combustion of polyvinylidene chloride (PVDC) with a quartz tubular furnace designed and fabricated to provide the desired combustion temperature and mixing state of combustion gas with air, it was found that at 800 degrees C or higher the level of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans [corrected] (PCDDs/PCDFs) resulting from PVDC combustion was no higher than that from heating air alone, and thus far below the levels which resulted from PVDC combustion at 750 degrees C or lower. The results provide the first laboratory confirmation of the relation between PVDC incineration temperature and PCDD/PCDF formation, and of the primary importance of high temperature, turbulence for mixing between air and combustion gas, and sufficient residence time, as governing factors for the minimization of PCDD/PCDF formation in municipal solid waste incinerators.

Method for the simultaneous determination of losartan and its major metabolite, EXP-3174, in human plasma by liquid chromatography-electrospray ionization tandem mass spectrometry

A liquid chromatography-electrospray ionization tandem mass spectrometric method was developed for the simultaneous determination of losartan and its major active metabolite, EXP-3174, in human plasma. The two analytes and the internal standard (DuP-167) were extracted from plasma under acidic conditions by using solid-phase extraction cartridges containing a sorbent of copolymer, poly(divinylbenzene-co-N-vinylpyrrolidone). The analytes were separated by LC equipped with a reversed-phase C18 column, and introduced into the mass spectrometer via the electrospray ion source with pneumatically-assisted nebulization. For LC-MS-MS samples, an isocratic mobile phase consisting of [0.1% triethylamine-0.1% acetic acid (pH 7.1)]-acetonitorile (65:35, v/v) was used, and the assay was monitored for the negative fragment ions of the analytes. The method demonstrated linearity from 1 to 1000 ng/ml for both losartan and EXP-3174. The limit of quantification for both compounds in plasma was 1 ng/ml. This assay method may be useful for the measurement of levels of the two compounds in clinical studies of losartan.

How vertebrate and invertebrate visual pigments differ in their mechanism of photoactivation

In vertebrate visual pigments, a glutamic acid serves as a negative counterion to the positively charged chromophore, a protonated Schiff base of retinal. When photoisomerization leads to the Schiff base deprotonating, the anionic glutamic acid becomes protonated, forming a neutral species that activates the visual cascade. We show that in octopus rhodopsin, the glutamic acid has no anionic counterpart. Thus, the "counterion" is already neutral, so no protonated form of an initially anionic group needs to be created to activate. This helps to explain another observation-that the active photoproduct of octopus rhodopsin can be formed without its Schiff base deprotonating. In this sense, the mechanism of light activation of octopus rhodopsin is simpler than for vertebrates, because it eliminates one of the steps required for vertebrate rhodopsins to achieve their activating state.

A novel rhodopsin kinase in octopus photoreceptor possesses a pleckstrin homology domain and is activated by G protein betagamma-subunits

G protein-coupled receptor kinases (GRKs) play an important role in stimulus-dependent receptor phosphorylation and desensitization of the receptors. Mammalian rhodopsin kinase (RK) and beta-adrenergic receptor kinase (betaARK) are the most studied members among known GRKs. In this work, we purified RK from octopus photoreceptors for the first time from invertebrate tissues. The molecular mass of the purified enzyme was 80 kDa as estimated by SDS-polyacrylamide gel electrophoresis, and this was 17 kDa larger than that of the vertebrate enzymes. Unlike vertebrate RK, octopus RK (ORK) was directly activated by betagamma-subunits of a photoreceptor G protein. We examined the effects of various known activators and inhibitors of GRKs on the activity of the purified ORK and found that their effects were different from those on either bovine RK or betaARK. To analyze the primary structure of the enzyme, we cloned the cDNA encoding ORK from an octopus retinal cDNA library. The deduced amino acid sequence of the cDNA was highly homologous to betaARK over the entire molecule, including a pleckstrin homology domain located in the C-terminal region, and homology to RK was significantly lower. Furthermore, Western blot analysis of various octopus tissues with an antibody against the purified ORK showed that ORK is expressed solely in the retina, which confirmed the identity of the enzyme as rhodopsin kinase. Thus, ORK appears to represent a unique subgroup in the GRK family, which is distinguished from vertebrate RK.

A novel monoantennary complex-type sugar chain found in octopus rhodopsin: occurrence of the Gal beta1-->4Fuc group linked to the proximal N-acetylglucosamine residue of the trimannosyl core

The N-linked sugar chains were liberated as oligosaccharides from octopus rhodopsin by hydrazinolysis. Most of the oligosaccharides were neutral, and separated into two major components by column chromatography using immobilized lectins and Bio-Gel P-4. Structural analysis of the one major component by sequential exoglycosidase digestion, chemical fragmentation in combination with methylation analysis revealed that it is a nonasaccharide; Man alpha1-->6(Gal beta1-->3GlcNAc beta1-->2Man alpha1-->3)Man beta1--> 4GlcNAc beta1-->4(Gal beta1-->4Fuc alpha1-->6)GlcNAc. This structure is quite unique in that a novel galactosylated fucose residue is attached to the reducing terminal N-acetylglucosamine residue.

[Efficacy and safety of sulbactam/cefoperazone for hepato-biliary infections]

We studied efficacy and safety of sulbactam/cefoperazone (SBT/CPT) in the treatment of biliary tract infections in hospitalized patients at 26 hospitals from February 1993 to March 1995. Secondary to dropout, 273 out of 338 patients entered in the study were evaluated, 127 patients with cholecystitis, 132 patients with cholangitis, and 14 patients with liver abscesses. Of these, 93 patients (34.1% had malignancy as an underlying disease. SBT/CPZ had an efficacy of 79.9% (218 patients; excellent: 52, good: 166), with the efficacy in patients with cholecystitis, cholangitis and liver abscess at 89.0% (113 patients), 77.3% (102 patients and 21.4% (3 patients), respectively. A significant difference (p < 0.05) was observed in the efficacy rates of patients with (59 patients [63.4%]) and without malignancy (159 patients [88.3%]). A total of 84 strains were isolated from bile specimens of 53 patients, and the major isolates were Escherichia coli, Pseudomonas aeruginosa and Enterococcus spp. Two or more bacterial strains were isolated simultaneously in 20 patients. Mild or moderate side effect (allergic reaction including rash etc.) were noted in 4 patients (1.18%), and laboratory abnormalities (increased GOT, etc.) were in 16 patients (4.71%) out of the total 338 patients. This study clearly demonstrated that SBT/CPZ retains its excellent clinical efficacy and safety profile, throughout its use over the past decade.

Selective deficiency of debrisoquine 4-hydroxylase activity in mouse liver microsomes

Cytochrome P450 enzymes belonging to the CYP2D subfamily have been shown to be one of determinants of the polymorphic drug oxidations in the human and the rat. Debrisoquine 4-hydroxylation is a typical reaction catalyzed by these enzymes. However, various strains of mice were observed to have much lower debrisoquine 4-hydroxylase activity than Wistar rats, whereas other monooxygenase activities in mice toward bunitrolol, propranolol, imipramine and amitriptyline, which are mediated by the CYP2D enzymes in the rat, were comparable to those of the rats. Immunoblot analysis of mouse liver microsomes with an antibody raised against a rat CYP2D enzyme indicated that the mouse liver contained a P450 enzyme(s) immunochemically related to the rat CYP2D enzyme. The antibody inhibited propranolol ring-hydroxylase and imipramine 2-hydroxylase activities, as well as testosterone 16alpha-hydroxylase activity, a typical reaction of mouse CYP2D9, but not debrisoquine 4-hydroxylase activity in mouse liver microsomes. We partially purified a P450 enzyme (designated P450 ML2d) from livers of male ddY mice by monitoring the cross-reactivity with the antibody. The partially purified enzyme was indicated to belong to the CYP2D subfamily from its N-terminal amino acid sequence, but the homology of the sequence to other CYP2D enzymes of the mouse (CYP2D9-11) was 62%, suggesting that P450 ML2d is a novel P450 enzyme. P450 ML2d had the oxidation activities for the rat CYP2D-substrates, such as propranolol 4-hydroxylation and imipramine 2-hydroxylation, in higher rates than those of the microsomes, but did not exhibit debrisoquine 4-hydroxylase activity. Our result is the first finding that a mouse CYP2D enzyme also metabolizes substrates for the rat CYP2D enzyme, in addition to steroids, but the enzyme had a limited specificity for the substrates of the CYP2D enzymes of the rat and the human.

Light-induced protein conformational changes in the photolysis of octopus rhodopsin

Light-induced protein conformational changes in the photolysis of octopus rhodopsin were measured with a highly sensitive time-resolved transient UV absorption spectrophotometer with nanosecond time resolution. A negative band around 280 nm in the lumirhodopsin minus rhodopsin spectra suggests that alteration of the environment of some of the tryptophan residues has taken place before the formation of lumirhodopsin. A small recovery of the absorbance at 280 nm was observed in the transformation of lumirhodopsin to mesorhodopsin. Kinetic parameters suggest that major conformational changes have taken place in the transformation of mesorhodopsin to acid metarhodopsin. In this transformation, drastic changes of amplitude and a shift of a difference absorption band around 280 nm take place, which suggest that some of the tryptophan residues of rhodopsin become exposed to a hydrophilic environment.

Identification of two palmitoyl groups in octopus rhodopsin

We determined the structure and site of fatty acid incorporated in octopus rhodopsin using a combination of fluorescence label and enzymatic cleavage methods in conjunction with fast-atom bombardment (FAB) mass spectrometry. A single peptide containing two adjacent cysteines, Cys337 and Cys338, was successfully isolated using the fluorescence from a dye conjugated to Cys345. The FAB mass spectrometric analysis of the peptide (323Phe-340Phe) revealed that two palmitoyl groups are linked to Cys337 and Cys338 via thioester bonds in octopus rhodopsin as in bovine rhodopsin.

Consecutive maintenance of human solitary and hereditary colorectal polyps in SCID mice

Recently, the sequential changes from adenoma to adenocarcinoma have been well studied in human colorectal carcinogenesis. To study the precise clonal changes from colorectal polyps to cancer, we have established an experimental system to maintain human colorectal polyps in severe combined immunodeficient (SCID) mice that have been improved by the selective inbreeding of C.B17-scid/scid homozygous male and female showing undetectable serum IgG and IgM (< 1 microgram/ml). Two of two solitary polyps from two nonhereditary colon polyp patients, four of five colon polyps from two Peutz-Jeghers' syndrome patients and one polypoid lesion from a familial polyposis coli (FAP) patient grew very slowly but steadily, at approximately one-tenth the rate of their malignant form, (i.e., adenocarcinoma), in the improved SCID mice and were maintained for a long period (more than 2 years), over several mouse generations. However, two polyps from FAP and Peutz-Jeghers' syndrome patients could not be transplanted further because of microinfection at the transplanted site due to incomplete sterilization of original human tumors prior to surgical operation (endoscopic polypectomy). Transplanted colon polyps had a semitransparent, soft and sticky appearance, with cells containing large amounts of mucin. Malignant transformation of human colon polyp to adenocarcinoma has not been observed during the maintenance period (about 2 years) in SCID mice. In the consecutively maintained human colon polyps, however, K-ras mutations were detected at codon 12, while these mutations were not found in their original polyps in the patients.

Simple purification and functional reconstitution of octopus photoreceptor Gq, which couples rhodopsin to phospholipase C

In invertebrate photoreceptors, illuminated rhodopsin activates multiple G proteins, which are assumed to initiate multiple phototransduction cascades. In this paper, we focused on one of the phototransduction cascades, which utilizes rhodopsin, a Gq-like G protein, and phospholipase C (PLC). A Gq-like G protein from octopus photoreceptors was successfully purified to apparent homogeneity as an active form by simple two-step chromatography. The purified G protein had an alpha beta gamma-trimeric structure consisting of 44-kDa alpha, 37-kDa beta, and 9-kDa gamma subunits. The 44-kDa alpha subunit was assigned to the Gq class by western blot with antiserum against mammalian Gq alpha and by partial amino acid sequencing of its proteolytic fragments. Light-dependent binding of GTP gamma S was observed when the purified octopus Gq was reconstituted with octopus rhodopsin that had been integrated into phospholipid vesicles. Octopus Gq activated PLC beta 1 purified from bovine brain dose-dependently in the presence of A1F4-. Finally, light- and GTP-dependent activation of PLC beta 1 was observed in a reconstitution system consisting of octopus rhodopsin, Gq, and bovine PLC beta 1.

Regioselectivity and substrate concentration-dependency of involvement of the CYP2D subfamily in oxidative metabolism of amitriptyline and nortriptyline in rat liver microsomes

Kinetic analysis of the metabolism of amitriptyline and nortriptyline using liver microsomes from Wister rats showed that more than one enzyme was involved in each reaction except for monophasic amitriptyline N-demethylation. The Vmax values particularly in the high-affinity sites for E-10-hydroxylation of both drugs were larger than those for Z-10-hydroxylations. Their E- and E-10-hydroxylase activities in Dark-Agouti rats, which are deficient for CYP2D1, were significantly lower than those in Wistar rats at a lower substrate concentration (5 microM). The strain difference was reduced at a higher substrate concentration (500 microM). A similar but a smaller strain difference was also observed in nortriptyline N-demethylase activity, and a pronounced sex difference (male > female) was observed in N-demethylation of both drugs in Wistar and Dark-Agouti rats. The reactions with the strain difference were inhibited concentration-dependently by sparteine, a substrate of the CYP2D subfamily, and an antibody against a CYP2D isoenzyme. The profiles of these decreased metabolic activities corresponded to that of the lower metabolic activities in Dark-Agouti rats. These results indicated that a cytochrome P450 isozyme in the CYP2D subfamily was involved in E- and Z-10-hydroxylations of amitriptyline and nortriptyline in rat liver microsomes as a major isozyme in a low substrate concentration range. It seems likely that the CYP2D enzyme contributes to nortriptyline N-demethylation.

Phylogenetic relationships among vertebrate visual pigments

Genomic DNA fragments in exon 4 of chicken, goldfish and salmon visual pigments were amplified by polymerase chain reaction, using oligonucleotide mixtures as primers, and hypothetical phylogenetic trees were drawn up from the deduced amino acid sequences. The results suggest that vertebrate visual pigments have evolved along at least five lines, and that these lines diverged from an ancestral gene before the bony fishes diverged from the rest of the higher vertebrates.

The biological significance of glycyrrhizin- and glycyrrhetinic acid derivative-induced selective phosphorylation of histones H2A and H2B by A-kinase in vitro

Histones H2A and H2B were found to be glycyrrhizin (GL)-binding proteins, because (i) the two histones H2A-H2B pairs were isolated selectively from the crude histone preparations of calf thymus by means of GL-affinity column chromatography (HPLC); (ii) phosphorylation of these two histones by A-kinase was remarkably stimulated by native GL or oGA (a derivative of glycyrrhetinic acid) at 20 microM; and (iii) in the crude histone preparations of calf thymus, these two histones were selectively phosphorylated by A-kinase in the presence of both dsDNA and 20 microM oGA or 20 microM GL. The provided data suggest that the GL-induced selective phosphorylation of histones H2A and H2B by A-kinase may be implicated in the transcriptional activation involved in the biological activities of the drug.

GTP-binding protein couples with metabotropic glutamate receptor in bovine retinal on-bipolar cell

GTP-binding protein (G protein) linking to metabotropic glutamate receptor of bovine retinal on-bipolar cell was studied by use of pharmacologically selective ligands, 2-amino-4-phosphonobutyric acid (APB) on bacterial toxin-catalyzed ADP-ribosylation and GTP gamma S-binding. In contrast to the electrophysiological findings reported, G protein coupling to APB-sensitive glutamate receptor served as a substrate for pertussis toxin but did not for cholera toxin. Several glutamate analogues effective on on-bipolar cell, as well as APB, increased GTP gamma S binding to retinal membranes devoid of rod outer segments. The enhancement of GTP gamma S binding by APB was completely abolished when the membranes were pretreated with pertussis toxin and NAD. These results suggest that, in retinal on-bipolar cell, the G protein which couples metabotropic glutamate receptor to hyperpolarizing response of the cell is sensitive to pertussis toxin.

Submassive hepatic necrosis induced by dichloropropanol

A hitherto undescribed industrial liver injury of fulminant form induced by dichloropropanol is reported. Two middle-aged men developed severe hepatic injury just after cleaning a dichloropropanol tank at a plant producing dichloropropanol. They died from hepatic failure 4 and 11 days respectively, after carrying out the work. Liver specimens taken at autopsy from one of the cases showed submassive hepatic necrosis. This accident prompted us to undertake an experimental study in rats of intraperitoneal one-shot injection of two isomeric substances of dichloropropanol, that is, 2,3-dichloro-1-propanol (DC1P) and 1,3-dichloro-2-propanol (DC2P). Saline was injected into the control rats. One, two, four, six, 24, 48, 72 h, and 1 week after the injection, rats in each group were sacrificed. Neither control nor DC1P-injected rats showed significant biochemical or histopathological abnormalities. DC2P-injected rats revealed elevations of transaminase from 6 h after the injections, and submassive necrosis of the liver was observed in many rats. It was concluded that the severe liver injuries in both the human cases and rats in our study were caused by DC2P.

[Brachial plexus block with a nerve stimulator and "around the needle" catheter technique]

Brachial plexus block using a nerve stimulator is an accurate procedure. But prolonged analgesic effect can not be obtained. Therefore we used "around the needle" catheter technique to have a long analgesic effect. A 20-gauge, 5-inch intravenous catheter (Angiocath) was threaded over a 23-gauge, 10-cm needle (Pole). We used axillary approach. The cathode of the nerve stimulator (NS-2CA, Professional Instrument company) is connected to the needle, and its anode is connected to the electrode on the surface of the skin. When the needle is introduced and advanced, 1 mA of electric current is applied for nerve stimulation. When the muscle twitch is obtained, a plastic cannula is then threaded off the needle into the axillary sheath. An infusion tube and three way stopcock is connected to the cannula. From 1988 to 1991 we had 31 cases. The success rate is about 90%. If we stimulate other nerves in the same sheath, it is not necessary to seek aimed one. But the musculocutaneous nerve is the only exception, because it may be stimulated outside the neurovascular sheath.

Primary neurilemoma of the thyroid gland: report of a case

Neurilemoma, like other non-epithelial tumors, seldom occurs in the thyroid gland. A 57-year-old man was first referred to our hospital with an asymptomatic anterior neck tumor. A solid tumor was detected in the right lobe of the thyroid and an enucleation of the thyroid tumor was performed. The tumor was 35 x 33 x 33 mm in size, and diagnosed as Antoni A type neurilemoma. We were only able to find seven previously reported detailed cases of primary neurilemoma of the thyroid gland. A review of these cases, however, revealed that neurilemoma tends to develop in the right lobe of the thyroid gland. An operation is thus considered necessary and an enucleation of the tumor is appropriate.

Infrared studies of octopus rhodopsin. Existence of a long-lived intermediate and the states of the carboxylic group of Asp-81 in rhodopsin and its photoproducts

The infrared absorption spectra of octopus rhodopsin and its photoproducts have been observed at 282K and 210K under irradiation of blue and orange light in a neutral condition. The acid metarhodopsin-minus-rhodopsin and lumirhodopsin-minus-rhodopsin difference spectra have been obtained. A new intermediate (called transient acid metarhodopsin) with a lifetime of about 5 s has been found to exist prior to acid metarhodopsin. The present results, together with the data obtained previously, give information on the state of the carboxylic group in the side chain of Asp-81, which is the only acidic amino-acid residue in the part of opsin buried inside the membrane. This carboxylic group is protonated throughout the transformation series, but its state changes on going from transient acid metarhodopsin to acid metarhodopsin. It is probable that these two photoproducts are different from each other only in the opsin moiety.

Reduction of leaky lymphocyte clones producing immunoglobulins and thymic lymphocytic leukemia by selective inbreeding of SCID (severe combined immunodeficiency) mice

Selective inbreeding of C.B17-scid/scid mouse pairs showing undetectable IgG and IgM has been carried out in order to reduce the mortality of mice by early occurrence of thymic lymphocytic leukemia and abnormal lymphocyte clones producing immunoglobulins, both of which inhibit the successful heterotransplantation of normal and neoplastic human tissues. Although the majority of C.B17-scid/scid mice showed undetectable (< 1 microgram/ml) or low level (< or = 25 micrograms/ml) of serum IgG and IgM, some produced abnormally high concentrations of IgG and IgM (> 25 micrograms/ml). The incidence of such mice showing higher levels of IgG was very high at F1 and F2 generation (10/55, 18.2%), but significantly low after the F3 generation (18/446, 4.0%, p << 0.001). Although leukemia incidence was very high at F4 to F5 generations (8/40, 20.0%), death from leukemia was not observed early in life (4-6 months after birth) at F7 to F10 generations (0/36, 0%, p < 0.01) and was very low during the age of 6-10 months after the F8 generation (11/66, 16.7% at F4 and F5 vs 4/93, 4.3% at F8-10), p < 0.01). Scid mice improved by the selective inbreeding will provide an invaluable experimental system for the heterotransplantation of normal and neoplastic human tissues.