The selective anaplastic lymphoma receptor tyrosine kinase inhibitor ASP3026 induces tumor regression and prolongs survival in non-small cell lung cancer model mice

Activation of anaplastic lymphoma receptor tyrosine kinase (ALK) is involved in the pathogenesis of several carcinomas, including non-small cell lung cancer (NSCLC). Echinoderm microtubule-associated protein like 4 (EML4)-ALK, which is derived from the rearrangement of ALK and EML4 genes, has been validated as a therapeutic target in a subset of patients with NSCLC. Here, we investigated the effects of ASP3026, a novel small-molecule ALK inhibitor, against ALK-driven NSCLC. ASP3026 inhibited ALK activity in an ATP-competitive manner and had an inhibitory spectrum that differed from that of crizotinib, a dual ALK/MET inhibitor. In mice xenografted with NCI-H2228 cells expressing EML4-ALK, orally administered ASP3026 was well absorbed in tumor tissues, reaching concentrations >10-fold higher than those in plasma, and induced tumor regression with a wide therapeutic margin between efficacious and toxic doses. In the same mouse model, ASP3026 enhanced the antitumor activities of paclitaxel and pemetrexed without affecting body weight. ASP3026 also showed potent antitumor activities, including tumor shrinkage to a nondetectable level, in hEML4-ALK transgenic mice and prolonged survival in mice with intrapleural NCI-H2228 xenografts. In an intrahepatic xenograft model using NCI-H2228 cells, ASP3026 induced continuous tumor regression, whereas mice treated with crizotinib showed tumor relapse after an initial response. Finally, ASP3026 exhibited potent antitumor activity against cells expressing EML4-ALK with a mutation in the gatekeeper position (L1196M) that confers crizotinib resistance. Taken together, these findings indicate that ASP3026 has potential efficacy for NSCLC and is expected to improve the therapeutic outcomes of patients with cancer with ALK abnormality.

YM155, a novel small-molecule survivin suppressant, induces regression of established human hormone-refractory prostate tumor xenografts

Various accumulating evidence suggests that survivin, a member of the inhibitor of apoptosis (IAP) family, plays an important role in drug resistance and cancer cell survival in many types of cancer, including hormone-refractory prostate cancer (HRPC). Here, we characterized YM155, a novel small-molecule survivin suppressant, using a survivin gene promoter activity assay. YM155 suppressed expression of survivin and induced apoptosis in PC-3 and PPC-1 human HRPC cell lines at 10 nmol/L. In contrast, YM155 up to 100 nmol/L showed little effect on expression levels of other IAP- or Bcl-2-related proteins. In a s.c. xenografted PC-3 tumor model in mice, 3-day continuous infusions of YM155 at 3 to 10 mg/kg induced massive tumor regression accompanied by suppression of intratumoral survivin. YM155 also completely inhibited the growth of orthotopically xenografted PC-3 tumors. No significant decreases in body weight were observed in mice treated with YM155 during the experimental period. Pharmacokinetic analyses indicated that YM155 is highly distributed to tumors and at concentrations approximately 20-fold higher than those in plasma. Our findings represent the first attempt to show tumor regression and suppression of survivin in p53-deficient human HRPC cells by a single small molecular compound treatment. Further extensive investigation of YM155 in many types of cancer, including HRPC, seems to be worthwhile to develop this novel therapeutic approach.

YM155, a novel small-molecule survivin suppressant, induces regression of established human hormone-refractory prostate tumor xenografts

Various accumulating evidence suggests that survivin, a member of the inhibitor of apoptosis (IAP) family, plays an important role in drug resistance and cancer cell survival in many types of cancer, including hormone-refractory prostate cancer (HRPC). Here, we characterized YM155, a novel small-molecule survivin suppressant, using a survivin gene promoter activity assay. YM155 suppressed expression of survivin and induced apoptosis in PC-3 and PPC-1 human HRPC cell lines at 10 nmol/L. In contrast, YM155 up to 100 nmol/L showed little effect on expression levels of other IAP- or Bcl-2-related proteins. In a s.c. xenografted PC-3 tumor model in mice, 3-day continuous infusions of YM155 at 3 to 10 mg/kg induced massive tumor regression accompanied by suppression of intratumoral survivin. YM155 also completely inhibited the growth of orthotopically xenografted PC-3 tumors. No significant decreases in body weight were observed in mice treated with YM155 during the experimental period. Pharmacokinetic analyses indicated that YM155 is highly distributed to tumors and at concentrations approximately 20-fold higher than those in plasma. Our findings represent the first attempt to show tumor regression and suppression of survivin in p53-deficient human HRPC cells by a single small molecular compound treatment. Further extensive investigation of YM155 in many types of cancer, including HRPC, seems to be worthwhile to develop this novel therapeutic approach.

Octaarginine-modified multifunctional envelope-type nanoparticles for gene delivery

This study describes a multifunctional envelope-type nano device (MEND) that mimics an envelope-type virus based on a novel packaging strategy. MEND particles contain a DNA core packaged into a lipid envelope modified with an octaarginine peptide. The peptide mediates internalization via macropinocytosis, which avoids lysosomal degradation. MEND-mediated transfection of a luciferase expression plasmid achieved comparable efficiency to adenovirus-mediated transfection, with lower associated cytotoxicity. Furthermore, topical application of MEND particles containing constitutively active bone morphogenetic protein (BMP) type IA receptor (caBmpr1a) gene had a significant impact on hair growth in vivo. These data demonstrate that MEND is a promising non-viral gene delivery system that may provide superior results to existing non-viral gene delivery technologies.

YM-359445, an Orally Bioavailable Vascular Endothelial Growth Factor Receptor-2 Tyrosine Kinase Inhibitor, Has Highly Potent Antitumor Activity against Established Tumors

PURPOSE

The vascular endothelial growth factor receptor-2 (VEGFR2) tyrosine kinase has been implicated in the pathologic angiogenesis associated with tumor growth. YM-359445 was a (3Z)-3-quinolin-2(1H)-ylidene-1,3-dihydro-2H-indol-2-one derivative found while screening based on the inhibition of VEGFR2 tyrosine kinase. The aim of this study was to analyze the efficacy of this compound both in vitro and in vivo.

EXPERIMENTAL DESIGN

We tested the effects of YM-359445 on VEGFR2 tyrosine kinase activity, cell proliferation, and angiogenesis. The antitumor activity of YM-359445 was also tested in nude mice bearing various established tumors and compared with other VEGFR2 tyrosine kinase inhibitors (ZD6474, CP-547632, CGP79787, SU11248, and AZD2171), a cytotoxic agent (paclitaxel), and an epidermal growth factor receptor tyrosine kinase inhibitor (gefitinib).

RESULTS

The IC50 of YM-359445 for VEGFR2 tyrosine kinase was 0.0085 micromol/L. In human vascular endothelial cells, the compound inhibited VEGF-dependent proliferation, VEGFR2 autophosphorylation, and sprout formation at concentrations of 0.001 to 0.003 micromol/L. These concentrations had no direct cytotoxic effect on cancer cells. In mice bearing various established tumors, including paclitaxel-resistant tumors, once daily oral administration of YM-359445 at doses of 0.5 to 4 mg/kg not only inhibited tumor growth but also reduced its vasculature. YM-359445 had greater antitumor activity than other VEGFR2 tyrosine kinase inhibitors. Moreover, in human lung cancer A549 xenografts, YM-359445 markedly regressed the tumors (73%) at a dose of 4 mg/kg, whereas gefitinib caused no regression even at 100 mg/kg.

CONCLUSION

Our results show that YM-359445 is more potent than orally bioavailable VEGFR2 tyrosine kinase inhibitors, which leads to great expectations for clinical applicability.

A role of androgen receptor protein in cell growth of an androgen-independent prostate cancer cell line

Prostate cancer, which develops due to androgen and is initially responsive to androgen deprivation therapy, often comes to acquire androgen deprivation therapy resistance in short order. We investigated the role of androgen receptor (AR) protein in an androgen-independent prostate cancer cell line using AR ligands and AR siRNA. Although the androgen-independent cell line scarcely responded to AR ligands, their growth was attenuated by ablation of AR protein by siRNA.

(+)-(2R,5S)-4-[4-Cyano-3-(trifluoromethyl)phenyl]-2,5-dimethyl-N-[6-(trifluoromethyl)pyridin-3- yl]piperazine-1-carboxamide (YM580) as an Orally Potent and Peripherally Selective Nonsteroidal Androgen Receptor Antagonist

A novel series of trans-N-aryl-2,5-dimethylpiperazine-1-carboxamide derivatives was synthesized and their androgen receptor (AR) antagonist activities and in vivo antiandrogenic effects were evaluated. Pharmacological assays indicated that compound 33 was a potent AR antagonist, and subsequent optical resolution provided (+)-(2R,5S)-4-[4-cyano-3-(trifluoromethyl)phenyl]-2,5-dimethyl-N-[6-(trifluoromethyl)pyridin-3-yl]piperazine-1-carboxamide (33a, YM580) which exhibited the most potent antiandrogenic activity. Unlike bicalutamide, compound 33a decreased the weight of rat ventral prostate in a dose-dependent manner (ED(50) = 2.2 mg/kg/day), and induced the maximum antiandrogenic effect, comparable to that of surgical castration, without significantly affecting serum testosterone levels. Compound 33a is a promising clinical candidate for prostate cancer monotherapy.

YM-201627: an orally active antitumor agent with selective inhibition of vascular endothelial cell proliferation

We developed an oral administration-compatible, small molecular weight antitumor agent, YM-201627 by screening for the inhibition of the proliferation of VEGF-stimulated HUVECs. YM-201627 selectively inhibited the proliferation of various endothelial cell lines induced by VEGF, bFGF, and FBS (at IC50s of 0.0039-0.12 microM), that would not be expected to have any direct antiproliferative effect on other cell types. YM-201627 inhibited angiogenesis in vitro at a concentration of 0.01 microM. In the in vivo studies, it inhibited microvessel formation induced by human melanoma A375 cells suspended in Matrigel (86% with twice-daily doses of 30 mg/kg). Moreover, once-daily oral dosing of YM-201627 to mice bearing A375 xenografts elicited significant antitumor activity (73% with daily doses of 10 mg/kg). These results suggest that YM-201627 is a selective growth inhibitor of endothelial cells, which may be useful for treatment of solid tumors.

Human expanded polyglutamine androgen receptor mutants in neurodegeneration as a novel ligand target

Androgen receptor (AR) plays key roles in various biological events, including pathological processes such as prostate cancer, androgen-insensitive syndrome, and spinal and bulbar muscular atrophy (SBMA). SBMA is caused by mutation of the expanded polyglutamine (polyQ) stretches in the AR gene. Recently, we established a Drosophila SBMA model that expresses the expanded polyQ hAR mutant in eyes, which monitors neurodegeneration as a rough eye phenotype. In addition, we showed that androgen binding to the mutant hAR causes structural alterations, leading to the onset of neurodegeneration in the fly eyes. In the present study, we examined whether the ligand-induced neurodegeneration via the hAR mutant is coupled with the known ligand-induced transactivation function of hAR. By testing several known AR antagonists and several of their structure-related compounds, we unexpectedly found that none of the AR ligands antagonized the hAR mutant neurodegeneration function, and surprisingly, compound 4-(4,4-dimethyl-2,5-dioxo-1-imidazolidinyl)-2-trifluoromethylbenzonitrile (RU56279) was more potent in inducing neurodegeneration. However, in vitro and in vivo mammalian assays showed that RU56279 exhibited the expected antagonistic activity with the same potency as those of the other compounds. Thus, these findings suggest the presence of a novel ligand-induced function of the polyQ hAR mutant in neurodegeneration that could not be prevented by known antagonists for the hAR transactivation function.

YM-231146, a Novel Orally Bioavailable Inhibitor of Vascular Endothelial Growth Factor Receptor-2, Is Effective against Paclitaxel Resistant Tumors

Chemotherapy using anticancer drugs induces serious the problem of multidrug resistance (MDR) in the cancer cells. In contrast, endothelial cells so rarely acquire MDR that antiangiogenesis therapy has recently been considered as an effective means for cancer chemotherapy. We screened compounds in the chemical library to find a novel and orally active antitumor agent with vascular endothelial growth factor receptor-2 tyrosine kinase (VEGF-R2 TK) inhibition. The result was YM-231146 (IC50=0.080 microM). YM-231146 inhibited VEGF-stimulated proliferation, VEGF-R2 autophosphorylation, and vessel sprout formation of human vascular endothelial cells at concentrations between 0.15-0.30 microM. However, YM-231146 did not inhibit cancer cell proliferation at these concentrations (IC50>5 microM). In the in vivo studies, once-daily oral dosing of YM-231146 to human cancer xenografts elicited antitumor activity at doses of 3-100 mg/kg. Moreover, YM-231146 completely inhibited tumor growth of paclitaxel-resistant cancer cells without decreasing body weight at a dose of 100 mg/kg. These results suggest that YM-231146 is a novel orally bioavailable inhibitor of VEGF-R2 that would be useful for the treatment of multidrug resistant tumors.

N-Arylpiperazine-1-carboxamide Derivatives: a Novel Series of Orally Active Nonsteroidal Androgen Receptor Antagonists

A novel series of N-arylpiperazine-1-carboxamide derivatives was synthesized and their androgen receptor (AR) antagonist activities and in vivo antiandrogenic properties were evaluated. Reporter assays indicated that trans-2,5-dimethylpiperazine derivatives are potent AR antagonists, and in this series trans-N-4-[4-cyano-3-(trifluoromethyl)phenyl]-N-(2,4-difluorophenyl)-2,5-dimethylpiperazine-1-carboxamide (18 g, YM-175735) exhibited the most potent antiandrogenic activity. Compared to bicalutamide, YM-175735 is an approximately 4-fold stronger AR antagonist and has slightly increased antiandrogenic activity, suggesting that YM-175735 may be useful in the treatment of prostate cancer.

Synthesis and Pharmacological Evaluation of Novel Arylpiperazine Derivatives as Nonsteroidal Androgen Receptor Antagonists

The search for novel antiandrogens by high-throughput screening (HTS) of the Yamanouchi chemical library led to the discovery of the lead compound (5), which possesses an arylmorpholine moiety. Through the optimization of the lead compound (5), we have found a series of novel arylpiperazine derivatives. Among them, 4-[4-cyano-(3-trifluoromethyl)phenyl]-N-(4-fluorophenyl)piperazine-1-carboxamide (22; YM-92088) exhibited a potent AR antagonistic activity with an IC(50) value of 0.47 microM in the reporter assay, which is more potent than bicalutamide (4) which has an IC(50) value of 0.89 microM.

Chemotherapy targeting methylthioadenosine phosphorylase (MTAP) deficiency in adult T cell leukemia (ATL)

Methylthioadenosine phosphorylase (MTAP) is an important enzyme used for the salvage of adenine and methionine. Cells lacking this enzyme are expected to be sensitive to purine synthesis inhibitors and/or methionine starvation. We reported previously that the MTAP gene is deleted in adult T cell leukemia (ATL) cells. In the present study, we expanded our series and used a real-time quantitative PCR assay for accurate diagnosis of the deletion and nine of 65 primary ATL samples (13.8%) were MTAP negative. In spite of this low incidence, ATL cells showed significantly higher sensitivity to L-alanosine, an inhibitor of de novo adenosine monophosphate (AMP) synthesis, than normal lymphocytes, suggesting that the MTAP gene is inactivated not only by deletion but also by other mechanisms. Indeed, a real-time quantitative RT-PCR assay disclosed that primary ATL cells had significantly lower MTAP mRNA expression than normal lymphocytes. Since MTAP-negative ATL cell lines also showed much higher sensitivity to L-alanosine than MTAP-positive ATL cell lines, we used these cell lines to investigate whether it is possible to develop selective therapy targeting MTAP deficiency. A substrate of MTAP, methylthioadenosine (MTA) or its substitutes rescued concanavalin A (Con A)-activated normal lymphocyte proliferation from L-alanosine toxicity. All the compounds except 5'-deoxyadenosine, however, also caused the undesirable rescue of MTAP-negative ATL cell lines. 5'-Deoxyadenosine had the desired ability to rescue hematopoietic progenitor cells without rescuing ATL cell lines. These results support the rationale for a chemotherapy regimen of L-alanosine combined with 5'-deoxyadenosine rescue in MTAP-deficient ATL.

Stabilization of androgen receptor protein is induced by agonist, not by antagonists

The action of nuclear receptor ligands in target tissues is specified mainly by the expression levels of their cognate nuclear receptors. The expression levels of these receptors are controlled through transcriptional and post-transcriptional events. Among post-transcriptional events, the effect of ligand on nuclear receptor protein turnover still remains largely unknown. Therefore, we studied the effects of agonist and antagonists on the turnover of the human androgen receptor (hAR) protein in stably transformed Chinese hamster ovary cells expressing exogenous hAR. Western blot analysis showed that the most potent androgen, dihydrotestosterone (DHT), stabilizes hAR with the induction of the transactivation function of hAR. However, this androgen-induced stabilization of hAR protein was abrogated by well-known androgen antagonists, hydroxyflutamide and bicalutamide (BIC), with inhibition of the transactivation function of hAR. Thus, the present study suggests that androgen antagonists exert their effects through, at least in part, abrogating the agonist-induced stabilization of hAR protein as well as blocking the ligand-induced transactivation function of hAR.

Bag1 proteins regulate growth and survival of ZR-75-1 human breast cancer cells

Bag1 proteins bind heat shock protein M(r) 70,000 (Hsp 70) family molecular chaperones and regulate diverse pathways involved in cell proliferation, apoptosis, and stress responses. Four isoforms of Bag1 can be produced from a single gene in humans, including a nuclear-targeted long version (Bag1L)and a shorter cytosolic isoform (Bag1). Because overexpression of Bag1and Bag1L has been reported in breast cancers, we explored the effects of Bag1 and Bag1L on the growth of ZR-75-1 human breast cancer cells cultured in vitro and in tumor xenograft models using immunocompromised mice. Cells stably transfected with expression plasmids encoding either Bag1 or Bag1L displayed comparable rates of growth in cultures containing 10% serum, compared with control-transfected ZR-75-1 cells. In contrast, ZR-75-1 cells stably expressing mutants of Bag1 or Bag1L, which lack the COOH-terminal domain (DeltaC) required for heat shock protein M(r) 70,000 binding, displayed retarded growth rates. When cultured without serum, the viability of control-transfected, as well as Bag1DeltaC- and Bag1LDeltaC-expressing, cells declined with time, whereas Bag1- and Bag1L-overexpressing ZR-75-1 cells survived for over a week in culture. Caspase protease activation induced by serum deprivation was also prevented by stable expression of either Bag1 or Bag1L in ZR-75-1 cells. In addition, sensitivity to anchorage dependence was restored partially in ZR-75-1 cells expressing dominant-negative Bag1DeltaC and Bag1LDeltaC. In tumor xenograft studies involving injection of ZR-75-1 cells into mammary fat pads of female nu/nu mice, ZR-75-1 cells expressing Bag1 or Bag1L formed 1.4-1.6-fold larger tumors compared with control-transfected cells, whereas tumors formed by Bag1DeltaC- and Bag1LDeltaC-expressing cells grew very slowly and reached sizes < one-third of tumors generated by Neo-control ZR-75-1 cells. Altogether, these findings demonstrate that Bag1 and Bag1L provoke similar changes in breast cancer cell growth and survival and suggest that interference with Bag1 or Bag1L function might be a useful strategy for opposing breast cancer.

[The new portable system for home enteral nutrition, Portermate, made a patient possible go out for a long time: report of a case]

The patient, who is received home enteral nutrition (HEN) for a long time in a day, has problems on moving all days. Now, we tried Portermate, which is new portable devices for HEN, in his clinical care. The patient is chronic pancreatitis, and his clinical problems becomes to be worse after he ate. He was under total enteral nutrition via jejunostomy. His clinical complications were almost controlled after HEN, but he has a few complains receiving enteral nutrition. He would not move easily, for an old HEN system was not compact to move. Portermate made him go everywhere he wanted any time. It extremely improved his QOL under HEN. He continues to use Portermate.

[Epidemiologic study of diabetic retinopathy in nine hospitals in the Aomori area]

PURPOSE

To examine the prevalence of diabetic retinopathy and the relationship between diabetic retinopathy and systemic risk factors.

METHODS

A cross sectional study of diabetic retinopathy was conducted on 1,826 eyes of 913 randomly selected patients with type 2 diabetes in 9 central hospitals in Aomori Prefecture and the surrounding district. Retinopathy levels and maculopathy were assessed by binocular funduscopy, fundus photography and, if necessary, by fluorescein angiography. Multiple logistic regression analysis was performed to determine independent effects of systemic risk factors on diabetic retinopathy.

RESULTS

The prevalence of background retinopathy was 31%, of preproliferative retinopathy 5%, and of proliferative retinopathy 5% in all patients. However, in 3 hospitals in which the patients were routinely examined by fluorescein angiography, background retinopathy was found to be present in 60%, preproliferative retinopathy in 5%, and prolifertive retinopathy in 7%. Maculopathy was found in 8% of diabetic patients and the prevalence was 11% in the eyes with background retinopathy, 40% with preproliferative retinopathy, and 50% with proliferative retinopathy. Multiple logistic regression analysis showed that retinopathy was significantly associated with duration of diabetes, methods of diabetic control, hypertension, nephropathy, and neuropathy.

CONCLUSION

The detection rate of background diabetic retinopathy by fluorescein angiography was twice as sensitive as that by binocular funduscopy and fundus photography. The prevalence of maculopathy increases with the progression of retinopathy. Several systemic risk factors have significant association with diabetic retinopathy and maculopathy.

Possible involvement of mast-cell activation in aspirin provocation of aspirin-induced asthma

BACKGROUND

Although there is increasing evidence of the importance of cysteinyl leukotrienes (LT) as mediators of aspirin-induced bronchoconstriction in aspirin-sensitive asthma, the cellular origin of the LT is not yet clear.

METHODS

Urinary concentrations of leukotriene E4 (LTE4), 11-dehydrothromboxane B2, 9alpha,11beta-prostaglandin F2, and Ntau-methylhistamine were measured during the 24 h following cumulative intravenous administration of increasing doses of lysine aspirin to asthmatic patients. In addition, the urinary concentrations of these metabolites were measured on 5 consecutive days in a patient who suffered an asthma attack after percutaneous administration of nonsteroidal anti-inflammatory drugs.

RESULTS

In aspirin-induced asthma patients (AIA, n=10), the basal concentration of urinary LTE4, but not the other metabolites, was significantly higher than that in aspirin-tolerant asthma patients (ATA, n=10). After intravenous aspirin provocation, the AIA group showed a 13.1-fold (geometric mean) increase in excretion of LTE4 during the first 3 h, and 9alpha,11beta-prostaglandin F2 also increased in the AIA group during the first 0-3 h and the 3-6 h collection period. Ntau-methylhistamine excretion was also increased, but to a lesser degree. Administration of aspirin caused significant suppression of 11-dehydrothromboxane B2 excretion in both the AIA and ATA groups. When the percentage of maximum increase of each metabolite from the baseline concentrations was compared between the AIA group and the ATA group, a significantly higher increase in excretion of LTE4, 9alpha,11beta-prostaglandin F2, and Ntau-methylhistamine was observed in the AIA group than the ATA group. An increased excretion of LTE4 and 9alpha,11beta-prostaglandin F2 has been detected in a patient who suffered an asthma attack after percutaneous administration of nonsteroidal anti-inflammatory drugs.

CONCLUSIONS

Considering that human lung mast cells are capable of producing LTC4, prostaglandin D2, and histamine, our present results support the concept that mast cells, at least, may participate in the development of aspirin-induced asthma.

Long-lasting memory of sounds combined with reward in rats

We investigated the effects of sound stimuli combined with reward on the subsequent sound discrimination. Water-deprived rats were exposed to one of two sounds (S+ or S-) in a trial, and licking a spout only during the presentation of S+ was rewarded with water. The percentage of trials in which licking occurred was calculated separately for S+ and S-, and sound discrimination was estimated from the difference in the percentage. S+ and S- were significantly discriminated during an 8 h period. In the second test after 1-2 weeks, sound discrimination for the same S+ and S- was significantly better than that for the S+ of the previous S- and S- of the previous S+. These findings indicate that the memory of the sounds combined with reward in the first test was maintained for 1-2 weeks.

Sequence dependence of post-tetanic potentiation after sequential heterosynaptic stimulation in the rat auditory cortex

1. To investigate the mechanisms for the coding stimulus sequence in the auditory cortex (AC), post-tetanic potentiation (PTP) was recorded after sequentially combined heterosynaptic stimulation was applied in rat AC slices. 2. Brief tetanic stimulation (TS) was applied at two sites on AC slices at intervals of 0.5-10 s. PTP of field potentials was induced by the earlier TS, rather than the later TS. PTP was followed by sequence-dependent long-term potentiation (LTP). 3. Using Ca(2+) imaging in the slices loaded with rhod-2, a Ca(2+) indicator, a sequence-dependent distribution of PTP was found in AC slices. 4. The sequence-dependent PTP in excitatory postsynaptic potentials (EPSPs) was observed in supragranular pyramidal neurons. 5. The sequence dependence of PTP was not significantly affected by 1 microM bicuculline, an antagonist of GABA(A) receptors, or 100 microM 2-hydroxysaclofen, an antagonist of GABA(B) receptors. 6. Depolarization and firing recorded in pyramidal neurons during the later TS were less vigorous than when the slices were incubated in the control medium. However, this suppression of the responses during the later TS was not observed in the presence of 50 microM atropine, an antagonist of muscarinic receptors. 7. PTP was induced by the earlier and later TS in the presence of 50 microM atropine, so that the sequence dependence of PTP was abolished. Pirenzepine (50 microM), an antagonist of muscarinic M1 receptors, but not methoctramine (30 microM), an antagonist of M2 receptors, eliminated the sequence dependence of PTP. 8. These findings suggest that the sequence dependence of PTP in AC might have a role in the temporal processing of auditory information on the scale of seconds.

Mechanisms of fluconazole resistance in Candida albicans isolates from Japanese AIDS patients

Four Candida albicans isolates, TIMM 3163, TIMM 3164, TIMM 3165 and TIMM 3166, with reduced fluconazole susceptibility were obtained from three AIDS patients in Japan, and the mechanisms of their drug resistance were studied. All isolates showed lower levels of intracellular accumulation of fluconazole than ATCC 10231, a susceptible control strain of C. albicans. Increased amounts of CDR1 and CDR2 mRNA encoding putative ATP binding cassette (ABC) transporters were associated with the azole resistance of all TIMM isolates, apart from TIMM 3164. In addition, increased Cdr1p levels were immunodetected in the cell membrane fractions of all the TIMM strains except for TIMM 3164. Gene amplification was not responsible for CDR1 overexpression and there were no significant differences in the mRNA levels of CDR3 or CDR4 (ABC transporters) in the azole-susceptible and -resistant cells. CaMDR1 (a major facilitator superfamily) gene expression was not observed in any of the resistant isolates or the control strain. These results suggest that energy-dependent drug efflux associated with increased expression of CDR1 and CDR2 is involved in the fluconazole resistance mechanisms in two of the four isolates, TIMM 3165 and TIMM 3166. TIMM 3164 demonstrated energy-dependent drug efflux without overexpression of CDR1-4 or CaMDR1, indicating that some other pump may be operating. Despite showing low levels of drug efflux and overexpression of CDR1 and CDR2, efflux in TIMM 3163 was not energy dependent, suggesting that the expressed Cdr1p non-functional Cdr1p and that other resistance mechanisms may operate in this strain.

[Activities of antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan. Levofloxacin--Surveillance Group]

The surveillance study was conducted to determine the antimicrobial activity of fluoroquinolones (ofloxacin, levofloxacin, ciprofloxacin, tosufloxacin) and other 20 antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan. The resistance to fluoroquinolones was remarkable in Enterococci, methicillin-resistant staphylococci and Pseudomonas aeruginosa from UTI. However, many of the common pathogens such as Streptococcus pneumoniae including penicillin-resistant isolates, methicillin-susceptible Stahylococcus aureus, Moraxella catarrhalis, the family of Enterobacteriaceae, Haemophilus influenzae including ampicillin-resistant isolates have been kept to be susceptible to fluoroquinolones. About 90% of P. aeruginosa isolates from RTI were susceptible to fluoroquinolones. In conclusion, the results from this surveillance study suggest that fluoroquinolones are useful in the treatment of various bacterial infections including respiratory infections.

Histological distribution of class III alcohol dehydrogenase in human brain

The distributions of class III alcohol dehydrogenase (ADH), a glutathione-dependent formaldehyde dehydrogenase, and class I ADH in the human brain were examined immunohistochemically. The most intense immunostaining of class III ADH was observed in the dendrites and cytoplasm of cerebellar Purkinje cells. Scattered cerebral cortical neurons in layers IV and V, and some hippocampal pyramidal neurons were also immunopositive. The neuronal distribution of class III ADH resembled that of the vulnerable neurons in patients with hypoxic encephalopathy, which in view of the intense staining in the Purkinje cells, raises the possibility that this enzyme contributes to the hypoxia and cerebellar degeneration suffered by chronic alcoholics. Perivascular and subependymal astrocytes, which contribute to the maintenance of the cerebral cellular milieu and isolate the brain from the systemic circulation and cerebrospinal fluid, were also class III ADH positive. As the substrates of this enzyme include intrinsic toxic formaldehyde, inflammatory intermediate of 20-hydroxy-leukoteiene B4, and possibly ethanol, the distribution of class III ADH immunostaining indicates this enzyme contributes to the defence of the brain against degenerative processes. The finding that, unlike ependymal cells, subependymal astrocytes were class III ADH positive, suggests this enzyme may be useful for differentiating astrocytes and ependymal cells.

Structure-activity relationships of a new antifungal imidazole, AFK-108, and related compounds

Fungicidal activity of widely used imidazole antifungal drugs in topical applications is not so strong in spite of their fungistatic activities against dermatophytes and pathogenic yeasts. In order to improve fungicidal activity of imidazole antifungal agents, a series of novel imidazole derivatives having a hydrophobic substituent derived from isoprenoid were synthesized. The efficacy of these compounds was evaluated with respect to direct cell-membrane damaging activity, ergosterol biosynthesis inhibition, minimum growth-inhibitory concentration (MIC) and therapeutic effect for experimental dermatophytosis of guinea pigs. Among the newly synthesized compounds, the geranyl derivative named AFK-108 (2a) showed the highest in vivo fungicidal activity with both cell membrane damaging activity and ergosterol biosynthesis inhibition in vitro.

[Episodic and semantic memory after traumatic brain injury in a child]

In an early-life, a memory disturbance affects the learning and school record directly. Furthermore, it may cause the problem of maltreatment or adaptation difficulty for school life. We report a child amnesia caused by a traumatic brain injury when she was 9 years old. We examined her episodic and semantic memory. We developed 3-steps tasks of recognition and recall for the post-accident episodic memory. First, the examiner presented the patient with four words orally including a label of her episode, and asked her to choose one that she felt familiar with (the recognition of the episodic label). Second, if the word she selected was correct, she was required to recall the episode related to the word (the recall of the episode). Third, if she could not recall the episode herself correctly, she was required to choose a correct sentence about the episode (the recognition of the episode). She could not recall episodes correctly, but produced confabulation instead. She showed, however, good recognition of each episode. Furthermore, we performed recognition tests of time, person, and place about the same post-accident episodes, which were poor especially for time. In semantic memory tasks, we examined about kanji characters (ideogram) learned from the first grade to the sixth grade and mathematical knowledge learned from the second grade to the sixth grade at elementary school ("What centimeters is equal to one meter?" or "Tell me the formula of the size of a circle." etc). We found that she showed a retrograde impairment for about one year. For both episodic and semantic memory, she showed an anterograde impairment. Because of the anterograde amnesia she could not acquire new facts, and also showed para-amnesia or confabulation. In a child with brain damage, neuropsychological assessment is important in predicting effect of rehabilitation and recovery of school performance.

Long-term potentiation of Ca2+ signal in the rat auditory cortex

The Ca2+ signal in supragranular layers of the rat auditory cortex (AC) was studied in slice preparations using rhod-2, a Ca2+ indicator. White matter stimulation elicited an increase in the Ca2+ signal, which was maximal in the image taken 34 ms after stimulation. This peak time was the same as that of the Ca2+ signal in pyramidal neurons injected with rhod-2. The intensity of the Ca2+ signal was proportional to the amplitude of the field potentials in supragranular layers. The Ca2+ signal was inhibited almost completely by 200 microM Ni2+ , but only slightly by 50 microM D-2-amino-5-phosphonovalerate (APV), an NMDA-receptor antagonist. Tetanic stimulation of the white matter or supragranular layers elicited long-term potentiation (LTP) of the Ca2+ signal in AC slices, but the potentiation was not clear in slices of the visual cortex (VC). The induction of LTP of the field potentials in AC slices was blocked by 50 microM APV or 50 microM Ni2+. These results indicate that Ca2+ influx through Ni2+ -sensitive Ca2+ channels in pyramidal neurons is potentiated by tetanic stimulation in parallel with LTP of neural activities and might be important for the induction of LTP in AC slices.

Irreversible impairment of inhibitory neurons and nitric oxide release in the neocortex produced by low temperature and hypoxia in vitro

Brain ischemia causes irreversible hyperexcitability, which may be attributed to irreversible impairment of inhibitory neurons. However, the conditions required for selective and irreversible impairment of inhibitory interneurons in vitro are unknown. In this study, we found that a combination of low temperature and hypoxia produced hyperexcitability in the neocortex. Neocortical tissue blocks isolated from rats were exposed to low temperature (1-3 degrees C) for 45 min and subsequently to room temperature (21-23 degrees C) for 60 min in the non-oxygenated medium. In experimental slices prepared from the processed blocks, hyperexcitability, similar to that elicited by an antagonist of GABA(A) receptors, was observed. Exposure of the neocortical tissue blocks to low temperature alone or room temperature alone did not elicit hyperexcitability. The excitability of pyramidal neurons, excitatory synaptic transmission and inhibitory effects of an agonist of GABA(A) receptors were normal in experimental slices. However, excitation of pyramidal neurons was inhibited after local stimulation of inhibitory neurons in control slices, but not in experimental slices. Nitric oxide (NO) release from cortical interneurons was also markedly reduced in experimental slices. These results indicate that irreversible impairment of neocortical inhibitory neurons was produced by low temperature combined with hypoxia produced in vitro.

Long-lasting enhancement of sound discrimination ability after sound exposure in rats

Changes in the sound discrimination ability of rats were investigated after sound exposure (SE) in a Skinner box. For estimation of the sound discrimination ability, two different amplitude-modulated (AM) sounds (S+ and S-) were presented to the rats deprived of water for 48 h. Pedal press behavior in response to only S+ was rewarded with water. The percentages of trials in which pedal press behavior occurred in response to S+ or S- were calculated separately, and test performance of the rats was determined from the difference between the percentages. Rats were exposed to AM sounds during SE of 48 h, and the sound discrimination test was carried out. Enhancement of discrimination between S+ and S- was elicited by SE in a stimulus-specific manner. Latent extinction of the pedal press behavior in response to sound stimuli was not clearly found after SE. The enhancement of test performance was detected 1-48 h after the cessation of SE, and was blocked by injection of an antagonist of N-methyl-D-aspartate receptors into the auditory cortex bilaterally, immediately before the initiation of SE. These results suggest that SE elicits enhancement of sound discrimination ability, and the responsible site is in the auditory cortex.

YM116, 2-(1H-imidazol-4-ylmethyl)-9H-carbazole, decreases adrenal androgen synthesis by inhibiting C17-20 lyase activity in NCI-H295 human adrenocortical carcinoma cells

The concentrations of androstenedione and dehydroepiandrosterone, products of C17-20 lyase, in the medium after a 6-hr incubation of NCI-H295 cells were decreased by YM116 (2-(1H-imidazol-4-ylmethyl)-9H-carbazole) (IC50: 3.6 and 2.1 nM) and ketoconazole (IC50: 54.9 and 54.2 nM). 17Alpha-hydroxyprogesterone, a product of 17alpha-hydroxylase, was increased by YM116 (1-30 nM) and by ketoconazole (10-300 nM) and then was decreased at higher concentrations of both agents (IC50: 180 nM for YM116, 906 nM for ketoconazole), indicating that YM116 and ketoconazole were 50- and 16.5-fold more specific inhibitors of C17-20 lyase, respectively, than 17alpha-hydroxylase. Compatible with these findings, progesterone, a substrate of 17alpha-hydroxylase, was increased by these agents. Cortisol production was inhibited by YM116 and ketoconazole (IC50: 50.4 and 80.9 nM, respectively). YM116 was a 14-fold more potent inhibitor of androstenedione production than cortisol production, whereas ketoconazole was a nonselective inhibitor of the production of both steroids. YM116 and ketoconazole inhibited the C17-20 lyase activity in human testicular microsomes (IC50: 4.2 and 17 nM, respectively). These results demonstrate that YM116 reduces the synthesis of adrenal androgens by preferentially inhibiting C17-20 lyase activity.

[Annual change of the pet in allergic patients home for ten years]

There are only few paper in Japan which reports the prevalence of pet keepers in the allergic population and also of the type of pets they keep. We made investigation on these points in 1337 allergic patients employing a questionnaire. Among 1337 patients, allergic conjunctivitis patients were found in 67, eczema patients in 118, allergic rhinitis patients in 368 and bronchial asthmatic patients in 1043. These number contained those who overlapped in symptoms. Approximately 43% of allergy patients are currently keeping the pet at present while 11.2% of the patient had kept the pet in the past. There were two peaks in the age when they began to keep a pet, 6 to 12 and 30 to 40 years of age. Trend in the past decade showed that both the dog and cat bred in foreign countries were increasing. About 80% of patients who own the foreign bred dogs keep them indoor. This ratio is increasing gradually. Another conspicuous change is the sharp increase in those who keep hamsters which occupied 20% of all the pet keeper in 1997. Percentages of the patient who recognizes the aggravation of their symptoms in eye, nose, skin and also as asthma often pet keeping is a about 10%. One out of 4 patients who keep the pet has a family member with rhinitis and/or asthma. We concluded that too many of the allergic patients keep the pet against their benefit and they must be informed that the pet could be the cause of allergy symptoms.

Layer-specific NO dependence of long-term potentiation and biased NO release in layer V in the rat auditory cortex

1. We investigated the role of nitric oxide (NO) in the induction of long-term potentiation (LTP) in slices prepared from the rat auditory cortex. 2. Tetanic stimulation of layer IV elicited LTP of field potentials in layer II-III (LTPII-III) and in layer V (LTPV). The magnitude of LTPII-III measured at 30 min after tetanic stimulation was 171 +/- 9% (n = 15, mean +/- s.e.m.) of the control measured before tetanic stimulation, while that of LTPV was 138 +/- 3% (n = 17). 3. NO synthase (NOS) inhibitors had no apparent effect on LTPII-III, but LTPV was significantly suppressed (P < 0.001). This suppression of LTPV was significantly antagonized by a NO donor (P < 0.001) or a cGMP analogue (P < 0.001). 4. Small non-pyramidal neurones in the auditory cortex were stained with an anti-neuronal NOS antibody. More neurones were stained with the antibody in the deeper cortical layers. 5. We measured neocortical NO release with electrochemical NO probes. Layer IV stimulation elicited significantly more NO release in layer V than in layer II-III (P < 0.001). The amplitude of the increase in NO concentration elicited by stimulation at 20 Hz for 5 s was 380 +/- 14 pM (n = 55) in layer V and 55 +/- 8 pM (n = 5) in layer II-III. 6. NO release in layer V was partially but significantly suppressed by non-NMDA (P < 0.002) or NMDA (P < 0.002) receptor antagonists. Simultaneous application of the antagonists of the two types blocked NO release almost completely. 7. These results clearly indicate the NO dependence of the induction of LTPV, and the greater NO release in the deeper layer of the rat auditory cortex.

Novel nonsteroidal inhibitor of cytochrome P450(17alpha) (17alpha-hydroxylase/C17-20 lyase), YM116, decreased prostatic weights by reducing serum concentrations of testosterone and adrenal androgens in rats

BACKGROUND

The purpose of this study was to determine the effects of a nonsteroidal C17-20 lyase inhibitor, 2-(1H-imidazol-4-ylmethyl)-9H-carbazole (YM116), on serum concentrations of androgens and ventral prostatic weight in rats.

METHODS

Serum concentrations of testosterone and of dehydroepiandrosterone sulfate and prostatic weights were measured in rats treated with YM116.

RESULTS

YM116 inhibited testicular C17-20 lyase competitively (Ki, 0.38 nM), and decreased the serum testosterone concentration in gonadotropin-releasing hormone-treated rats (ED50, 0.7 mg/kg), indicating that YM116 was about 21-24 times more potent than other C17-20 lyase inhibitors such as ketoconazole and liarozole, and was twice as potent as CB7630. YM116 also reduced dehydroepiandrosterone sulfate levels in ACTH-treated castrated rats (ED50, 11 mg/kg). YM116 (40 mg/kg, p.o., for 2 weeks) was almost comparable to bilateral orchiectomy with respect to the time course and magnitude of the reduction in prostatic weight. Each of these two treatments decreased the prostatic weight 3 days following the treatment. Contrarily, leuprolide transiently increased the prostatic weight and then decreased it. YM116 (100 mg/kg) had no effect on the serum cortisol level in guinea pigs, and slightly decreased the serum aldosterone level in rats.

CONCLUSIONS

YM116 is a selective C17-20 lyase inhibitor which decreases rat prostatic weight by reducing androgen production in the testes and adrenal glands.

Scar tissue distribution on palates and its relation to maxillary dental arch form

OBJECTIVE

This study investigated the relationship between maxillary dental arch form and distribution of postsurgical scar tissue on previously denuded bone in isolated cleft palate patients.

METHOD

The palatal blood flow of 21 Japanese isolated cleft palate patients (6 males, 15 females) was examined by laser doppler flowmetry to determine the scar tissue areas. All had undergone pushback operations for palatal repair at around 18 months of age. Tissue blood flow was examined at a time ranging from 11 years, 5 months to 19 years, 9 months of age. To evaluate the maxillary dental arch form, dental casts obtained at the start of orthodontic treatment (a mean age of 8 years, 4 months) were analyzed.

RESULTS/CONCLUSIONS

Scar tissue distribution in the 21 cases was classified into five types. Characteristic features in the maxillary dental arch form were found in each of the five types according to the extent of the scar tissue. It was evident that the severity of the maxillary dental arch constriction was closely related to the scar tissue distribution on palates.

[Measurement of theophylline concentrations by AccuMeter--comparison with the EIA method]

Theophylline is widely used for treating patients with bronchial asthma. However, since the therapeutic concentration range is narrow, adverse reactions are frequent and often difficult to control, making monitoring of theophylline concentration mandatory for its efficient and safe use. In this study, we employed the AccMeter which allowed us to measure theophylline concentrations quickly and with ease, and compared it with EIA method. AccMeter is a kit which consists of two parts. One part consists of a chromatopaper with antitheophylline mouse monoclonal antibody fixed on it, on which a smaple is applied with enzyme-linked theophylline. The other part consists of a coloring solution. We used a part of arterial blood samples collected for gas analysis as trial samples. Both whole blood and plasma from 50 patients who did or did not receive theophlline were analysed. Plasma portions were also used for measurements by the EIA method. Results from all three measurements were almost identical, and showed good correlation. The time necessary for measurement using AccMeter was about 20 minutes. We consider this method to be useful for clinics due to its simplicity and ease of handling, and the accuracy of the results obtained.

[A new device for allergen skin testing]

We have made a new device for allergen skin testing, which can be used easily. It consists of two parts. One, several gears are fixed on a board in a row, and when one gear goes round, other gears also go round simultaneously. A disposable needle is attached to each gear. A semi-spherical hole is made in the lower surface of a disposable needle, and a sharp needle is fixed in, but not at the centre of the hole. The other, small tanks are arranged in a row at the same distance as the gears. When the disposable needles are inserted to the tanks filled with allergen extract, it is hold in a semi-spherical hole by surface tension. The allergen extracts go intradermally, when the needles move semi-circular on a human skin. We performed skin tests to 23 patients with this device, and got satisfactory results as screening tests.

Acute neural damage in the rat neocortex in vitro induced by a combination of anoxia and mechanical stress

To elucidate the mechanisms of neural damage after brain ischemia, rat neocortical slices were exposed to anoxia at room temperature for 1 h, and other slices were prepared from the neocortical blocks exposed to anoxia at room temperature for 1 h. Field potentials elicited by the stimulation of layer IV were recorded in supragranular layers in these slices. No clear damage was observed electrophysiologically or morphologically in these slices. In contrast, a complete loss of the trans-synaptic field potentials and a decrease in the density of the cells stained with Neutral Red were elicited by injecting an anoxic medium into the neocortical blocks at room temperature for 1 h. In the slice preparations, the injection of the anoxic medium failed to reproduce clear neural damage, while a combination of mechanical stress and anoxia elicited a complete loss of trans-synaptic potentials; this was alleviated by Gd3+ (50 microM) and D(-)-2-amino-5-phosphonovaleric acid (100 microM). These results indicate that a combination of mechanical stress and anoxia produces acute and severe neural damage even at room temperature in vitro. The mechanism of the damage and the relationship between the neural damage in vitro and in vivo are discussed.

Comparison of long-term potentiation between the auditory and visual cortices

Long-term potentiation of supragranular field potentials was evoked following tetanic stimulation of the white matter in the auditory cortex of adult rats. LTP corresponded to potentiation in orthodromic firing of supragranular pyramidal neurons. The induction of LTP depended on the activation of NMDA receptors. LTP was larger in the auditory than the visual cortex.

Importance of polysynaptic inputs and horizontal connectivity in the generation of tetanus-induced long-term potentiation in the rat auditory cortex

Supragranular pyramidal neurons in the adult rat auditory cortex (AC) show marked long-term potentiation (LTP) of population spikes after tetanic white matter stimulation (TS). For determination of whether this marked LTP is specific to AC, LTP in rat AC slices was compared with LTP in slices of the visual cortex (VC). The amplitude of TS-induced LTP in AC was twice that in VC. LTP of EPSPs was also studied with perforated patch or whole-cell recording. Although the amplitude of TS-induced LTP of EPSPs in AC was larger that in VC, no cortical difference was found in LTP elicited by low-frequency stimulation paired with current injection. Neocortical LTP is dependent on the activation of NMDA receptors, and induction of LTP requires postsynaptic depolarization for removal of Mg2+ blockade of NMDA receptors. The postsynaptic depolarization elicited by TS in supragranular pyramidal neurons in AC was significantly larger than that in VC. Cutting of supragranular horizontal connections resulted in a decrease in the depolarization amplitude in AC but an increase in the depolarization amplitude in VC. The cortical difference in TS-induced LTP was diminished in the slices in which horizontal connections in supragranular layers were cut. The estimated density of horizontal axon collaterals of supragranular pyramidal neurons in AC was approximately twice that in VC. These results strongly suggest that the marked polysynaptic and postsynaptic depolarization during TS and the resulting marked LTP in AC are attributed to well developed horizontal axon collaterals of supragranular pyramidal neurons in AC.

Inhibitory effects of a novel aromatase inhibitor, YM511, on growth of endometrial explants and insulin-like growth factor-I gene expression in rats with experimental endometriosis

Estrogen deprivation therapy effectively prevents progress of endometriosis but the precise mechanism by which estrogen stimulates growth of endometriotic implants is still unknown. We examined effects of hypoestrogenic state induced by ovariectomy, gonadotropin-releasing hormone agonist (leuprolide) or aromatase inhibitor (YM511), on growth of experimental endometrial explant, a section of endometrium transplanted under the renal capsule, in rats. Ovariectomy gradually reduced the volume of endometrial explants for 21 days. YM511 (0.1 mg/kg) and leuprolide (1 mg/rat) completely reduced volume of endometrial explants but they differed widely in the onset of inhibitory action. YM511 prevented growth of explants on day 4 but leuprolide had no inhibitory effect until day 15. YM511 dose-dependently reduced volume of endometrial explants and its minimum effective dose was 0.04 mg/kg. Insulin-like growth factor-I (IGF-I) mRNA expression in endometrial explant and uterus was examined on day 4. YM511 decreased IGF-I expression in endometrial explant and uterus by 58% and 48%, respectively. Reductions of the extent of IGF-I expression by YM511 and ovariectomy were comparable. A significant correlation between the volume and IGF-I mRNA expression in endometrial explant suggests that local expression of this gene may play an important role in stimulating growth of endometrial explants.

Studies on aromatase inhibitors. IV. Synthesis and biological evaluation of N,N-disubstituted-5-aminopyrimidine derivatives

In order to study the potency of the 5-aminopyrimidine skeleton as an aromatase inhibitor, we synthesized various N,N-disubstituted-5-aminopyrimidine derivatives and evaluated their aromatase-inhibitory activity (in vitro) and their inhibitory activity on pregnant mare serum gonadotropin (PMSG)-induced estrogen synthesis (in vivo). Compounds with the fluoro-substituted benzyl group showed potent aromatase inhibition. Among them, 5-[(4-cyanophenyl)(3,5-difluorobenzyl)amino]pyrimidine (5w, YM553) was a highly potent compound with an IC50 value of 0.038 nM for aromatase from human placenta. Its inhibitory effect was approximately four times greater than that of YM511. In addition, YM553 was a weak inhibitor of other enzymes involved in steroid hormone synthesis. These results indicate that YM553, as well as YM511 (a 4-amino-4H-1,2,4-triazole derivative), is a promising agent for the treatment of estrogen-dependent diseases.

[Correlation between quantitative EEG and cerebral blood flow and oxygen metabolism in patients with dementia of Alzheimer type]

Quantitative scalp EEG and cerebral blood flow (CBF) and oxygen metabolism (CMRO2) measured by the steady-state 15O technique and positron emission tomography were studied in 19 patients with mild to moderate dementia of Alzheimer type (DAT) and age-matched controls (EEG = 19, PET = 6). Scalp electrodes were placed according to the international 10-20 method except for Cz, T3, and T4. To evaluate the relative changes in power for each frequency band between the two groups, the percentage power fraction (percentage power for each frequency band at site compared to the total power at that site; %delta for 2.0-3.8 Hz, %theta for 4.0-7.8 Hz, %alpha for 8.0-12.8 Hz, %beta for 13.0-25.4 Hz) was calculated. Compared with controls, DAT patients showed a significant decrease in %alpha, while significant increases in %theta at all electrodes, and significant increases in %delta at the temporal, parietal and occipital electrodes were observed. The patient groups displayed a significant decrease in rCBF and rCMRO2 in the parietal, temporal, and frontal cortices, but the reduction in rCMRO2 was less remarkable than that of rCBF. %Theta at P3, O1 and O2 showed a significant negative correlation with rCBF, and %theta at P3, O1 showed a significant negative correlation with rCMRO2. %Delta at P3, P4 and T5 was significantly negatively correlated with rCBF in the corresponding regions, and %alpha at almost all the electrodes (except O1, F3, P3) was significantly positively correlated with rCBF in the corresponding regions. %Delta and %alpha did not show any significant correlation with rCMRO2.

Studies on aromatase inhibitors. III. Synthesis and biological evaluation of [(4-bromobenzyl)(4-cyanophenyl)amino]azoles and their azine analogs

A series of [(4-bromobenzyl)(4-cyanophenyl)amino]azoles and their azine analogs, which have the side chain of the selective aromatase inhibitor YM511, were synthesized and evaluated for aromatase-inhibitory activity (in vitro) and for pregnant mare serum gonadotropin (PMSG)-induced estrogen synthesis inhibitory activity (in vivo). Among these aza-heterocycles, the pyrimidin-5-yl derivative (6a) was the most potent aromatase inhibitor and its in vitro inhibitory activity was comparable to that of YM511. Compound 6a also showed weak inhibitory activity on aldosterone synthesis. These data indicated that the pyrimidin-5-yl moiety is useful as a new azole fragment in place of the 4H-1,2,4-triazol-4-yl moiety of the aromatase inhibitor YM511.

Studies on aromatase inhibitors. II. Synthesis and biological evaluation of 1-amino-1H-1,2,4-triazole derivatives

1-N,N-Disubstituted amino-1-H-1,2,4-triazole derivatives were prepared and evaluated for aromatase-inhibitory activity (in vitro) and for the inhibitory activity on pregnant mare serum gonadotropin (PMSG)-induced estrogen synthesis (in vivo). 1-N-para-Substituted benzylamino derivatives, having an electron-withdrawing group on the phenyl moiety, exhibited aromatase-inhibitory activity in vitro and in vivo. Among them, 1-[(4-nitrobenzyl)(4-nitrophenyl) amino]-1H,1,2,4-triazole (5b) was the most potent aromatase inhibitor. These 1-N-benzylamino derivatives also showed relatively strong inhibitory activity on aldosterone synthesis, indicating that the selectivity of these derivatives for aromatase inhibition was not sufficient in comparison with that of the 4-amino-4H-1,2,4-triazole derivatives.

Studies on aromatase inhibitors. I. Synthesis and biological evaluation of 4-amino-4H-1,2,4-triazole derivatives

Various 4-N-substituted amino-4H-1,2,4-triazole derivatives were synthesized and evaluated for aromatase-inhibitory activity (in vitro) and for pregnant mare serum gonadotropin (PMSG)-induced estrogen synthesis-inhibitory activity (in vivo). The 4-(4-cyanophenyl) amino derivative and 4-(4-nitrophenyl)amino derivative, each possessing a strong electron-withdrawing group on the phenyl moiety, showed potent aromatase-inhibitory activity. Structure-activity relationship studies indicated that 4-[(4-bromobenzyl)(4-cyanophenyl)amino]-4H-1,2,4-triazole (5k, YM511) is a highly potent aromatase inhibitor with IC50 values of 0.4 and 0.12 nM in in vitro experiments using rat ovary and human placenta, respectively, and an in vivo ED50 of 0.002 mg/kg in rats on oral administration. YM511 was also a weak inhibitor of other steroid hormone synthesis enzymes. These data suggest that YM511 is a highly selective aromatase inhibitor and may be a useful agent for the treatment of estrogen-dependent diseases such as breast cancer.

Long-term potentiation of supragranular pyramidal outputs in the rat auditory cortex

In supragranular layers of the rat auditory cortex, white matter stimulation produces antidromic and transsynaptic field potentials, of which only the latter shows long-term potentiation (LTP) following tetanic stimulation of the white matter. In this study, we investigated the cells responsible for the LTP. The transsynaptic field potentials, excitatory postsynaptic potentials (EPSPs), and orthodromic spikes were blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (10 microM), but not by D-2-amino-5-phosphonovalerate (D-AP5, 50 microM). The latency of EPSPs was constant, while that of transsynaptic field potentials and orthodromic spikes was shortened by the increase in stimulus intensity. Appearance of antidromic field potentials and antidromic spikes at strong stimulus intensities were accompanied by reduction in amplitude of transsynaptic field potentials and elimination of orthodromic spikes, respectively. Morphological identification of neurons showing antidromic spikes by intracellular injection of biocytin revealed that most of them were supragranular pyramidal cells. The effects of tetanic stimulation were studied by intracellular recording in seven neurons showing antidromic spikes, and it was found that only two of them showed LTP of EPSP slope. However, in all of the other eight units showing antidromic spikes and recorded extracellularly, LTP was clearly observed in orthodromic firing probability. The LTP induction in the orthodromic firing probability was blocked by D-AP5. These findings indicate that the LTP in field potentials corresponds to LTP in supragranular pyramidal outputs, and the input-output relationship in neural networks of the adult rat auditory cortex is strongly modulated by LTP.

Inhibitory effect of a novel non-steroidal aromatase inhibitor, YM511 on the proliferation of MCF-7 human breast cancer cell

The proliferation of MCF-7, human breast cancer cell line, was stimulated by testosterone and estradiol. The aromatase activity in MCF-7 cells, which catalysed the conversion of testosterone to estradiol, was inhibited by a novel non-steroidal aromatase inhibitor, YM5111, with the IC50 of 0.2 nM, indicating that its inhibitory activity was 5.5 times more potent than that of CGS 16949A. YM511 inhibited the proliferation of MCF-7 stimulated by testosterone but did not inhibit the cell proliferation stimulated by estradiol. The IC50 values of YM511 for cell growth and DNA synthesis were 0.13 nM and 0.18 nM, respectively, demonstrating that YM511 was about 3-5 times more potent than CGS 16949A and had no anti-estrogenic or cytotoxic activity. YM511 significantly inhibited testosterone-stimulated transcriptional activation of estrogen-responsive element (ERE) in MCF-7 cells transfected transiently with ERE-luciferase reporter plasmid. The IC50 of YM511 for transactivation was 0.36 nM, suggesting that its inhibitory potency was comparable to the inhibition of aromatase activity of MCF-7 cells. These data may indicate that the inhibition by YM511 of cell proliferation of MCF-7 is attributed to the decreased production of estrogen due to the inhibition of aromatase activity. YM511 may be useful in the treatment of estrogen-dependent cancers.

[Strategy of drug development for hormone-dependent tumor]

It is established that estrogen and androgen facilitate the proliferation of breast and prostate cancers. Hormonal therapy for these tumors using agents which inhibit hormone synthesis (inhibitors of aromatase and lyase) or bind hormone receptor have been used. However, some patients become resistant gradually during the hormonal therapy. Furthermore, QOL of patients was impaired by the side effects associated with the therapy, such as decreases in bone density, libido, and potency. The osteoporosis is a potential concern with the prolonged use of antiestrogen. The beneficial effect of estrogen receptor antagonist, tamoxifen on breast cancer has been established, but this agent may increase the proliferation of endometrium, which may increase the incidence of uterine cancer. Tamoxifen is a partial agonist, leading to the increase in transcriptional activity. Recently, ICI-164.384 is reported to be a pure antagonist and effective in tamoxifen-refractory tumor. Hopefully, pure antiandrogen will be available in the near future. There are reports suggesting that several specific and tissue-specific factors are involved in transcriptional activity of sex steroid hormone receptors. It is likely that these factors are novel targets for drugs which have a high potency and organ-or tissue-selective antagonist of sex steroid hormone for the treatment of hormone-dependent cancers.

Functional brain block preparation of the rat auditory cortex

To maintain neural functions in brain block preparations of the rat auditory cortex in vitro, a pressurized oxygenated medium was injected into the blocks. Distribution of indigo carmine contained in the injection medium indicated that a columnar region of 1-2 mm in diameter was homogeneously perfused from the white matter to the pial surface. Stimulation of cortical layers just above the white matter produced supragranular field potentials of two negative peaks. They represented antidromic and postsynaptic activities, of which only the latter was blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 10 microM). The depth profile and temperature-dependency of field potentials in the blocks were very similar to those recorded in usual slice preparations. The responses in blocks were recorded stably for several hours. The functional brain block preparation may be a useful tool for analyses of neocortical neural networks in vitro.

The potent and selective inhibition of estrogen production by non-steroidal aromatase inhibitor, YM511

YM511 inhibited aromatase activities in microsomes from rat ovary and human placenta competitively (IC50s: 0.4 and 0.12 nM, respectively). YM511 was about 3 times more potent than other aromatase inhibitors, such as CGS 16949A, CGS 20267 and R 76713. YM511 decreased the contents of estradiol stimulated by pregnant mare's serum gonadotropin in rat ovary with an ED50 of 0.002 mg/kg, indicating that YM511 was equipotent to CGS 20267 and 3 times more potent than the other two inhibitors. Serum estradiol levels in female rats were reduced by YM511 at 0.01 mg/kg into the ovariectomized range. YM511 at 1 mg/kg for 2 weeks decreased rat uterine weight to levels comparable to ovariectomy, showing it was 10 times more potent than other inhibitors. But the maximal inhibitory effect of tamoxifen failed to reach ovariectomized level. YM511 slightly inhibited production of other steroid hormones in vitro and in vivo. The IC50s of YM511 for aldosterone and cortisol production from adrenal cells were from 5500 to 9800 times higher than that for rat ovarian aromatase and 130,000 times higher for testosterone production, indicating that YM511 is a highly specific aromatase inhibitor. The data suggest that YM511 may be a potent and selective agent for suppressing estrogen-dependent action without affecting serum levels of other steroid hormones.