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The energy band structure of the conduction band (energy-momentum relation of electrons) is crucial to understanding the electron transport of crystalline materials. In this paper, we describe an angle-resolved low-energy inverse photoelectron spectroscopy (AR-LEIPS) apparatus that examines the conduction band structures of materials sensitive to the electron beam, such as organic semiconductors and organic-inorganic hybrid perovskites. The principle of this apparatus is based on AR inverse photoelectron spectroscopy. To minimize radiation damage and improve energy resolution, we employed our previous approach used in LEIPS [H. Yoshida, Chem. Phys. Lett. 539-540, 180 (2012)]. We obtained an overall energy resolution of 0.23 eV with a momentum resolution of 0.9 nm-1 at the electron kinetic energy of 2 eV or higher., (© 2023 Author(s). Published under an exclusive license by AIP Publishing.)

Background: Mixed lineage leukemia 1-rearranged (MLL1-r) acute leukemia patients respond poorly to currently available treatments and there is a need to develop more effective therapies directly disrupting the Menin‒MLL1 complex. Small-molecule-mediated inhibition of the protein‒protein interaction between Menin and MLL1 fusion proteins is a potential therapeutic strategy for patients with MLL1-r or mutated-nucleophosmin 1 (NPM1c) acute leukemia. In this study, we preclinically evaluated the new compound DS-1594a and its salts., Methods: We evaluated the preclinical efficacy of DS-1594a as well as DS-1594a·HCl (the HCl salt of DS-1594a) and DS-1594a·succinate (the succinic acid salt of DS-1594a, DS-1594b) in vitro and in vivo using acute myeloid leukemia (AML)/acute lymphoblastic leukemia (ALL) models., Results: Our results showed that MLL1-r or NPM1c human leukemic cell lines were selectively and highly sensitive to DS-1594a·HCl, with 50% growth inhibition values < 30 nM. Compared with cytrabine, the standard chemotherapy drug as AML therapy, both DS-1594a·HCl and DS-1594a·succinate mediated the eradication of potential leukemia-initiating cells by enhancing differentiation and reducing serial colony-forming potential in MLL1-r AML cells in vitro. The results were confirmed by flow cytometry, RNA sequencing, RT‒qPCR and chromatin immunoprecipitation sequencing analyses. DS-1594a·HCl and DS-1594a·succinate exhibited significant antitumor efficacy and survival benefit in MOLM-13 cell and patient-derived xenograft models of MLL1-r or NPM1c acute leukemia in vivo., Conclusion: We have generated a novel, potent, orally available small-molecule inhibitor of the Menin-MLL1 interaction, DS-1594a. Our results suggest that DS-1594a has medicinal properties distinct from those of cytarabine and that DS-1594a has the potential to be a new anticancer therapy and support oral dosing regimen for clinical studies (NCT04752163)., (© 2023. The Author(s).)

The FGFR4/FGF19 signaling axis is overactivated in 20% of liver tumors and currently represents a promising targetable signaling mechanism in this cancer type. However, blocking FGFR4 or FGF19 has proven challenging due to its physiological role in suppressing bile acid synthesis which leads to increased toxic bile acid plasma levels upon FGFR4 inhibition. An FGFR4-targeting antibody, U3-1784, was generated in order to investigate its suitability as a cancer treatment without major side effects.U3-1784 is a high-affinity fully human antibody that was obtained by phage display technology and specifically binds to FGFR4. The antibody inhibits cell signaling by competing with various FGFs for their FGFR4 binding site thereby inhibiting receptor activation and downstream signaling via FRS2 and Erk. The inhibitory effect on tumor growth was investigated in 10 different liver cancer models in vivo The antibody specifically slowed tumor growth of models overexpressing FGF19 by up to 90% whereas tumor growth of models not expressing FGF19 was unaffected. In cynomolgus monkeys, intravenous injection of U3-1784 caused elevated serum bile acid and liver enzyme levels indicating potential liver damage. These effects could be completely prevented by the concomitant oral treatment with the bile acid sequestrant colestyramine, which binds and eliminates bile acids in the gut. These results offer a new biomarker-driven treatment modality in liver cancer without toxicity and they suggest a general strategy for avoiding adverse events with FGFR4 inhibitors., (©2019 American Association for Cancer Research.)

Several studies have reported on the beneficial effects of memantine on behavioral and psychological symptoms of dementia (BPSD) in patients with Alzheimer's disease. However, the effects of memantine on BPSD-like behaviors in animals have not been well addressed. Here, the effects of memantine on memory disturbance and BPSD-like behaviors were evaluated in thiamine-deficient (TD) mice. Memantine (3 and 10 mg/kg, b.i.d.) was orally administered to ddY mice fed a TD diet for 22 days. During the treatment period, the forced swimming test, elevated plus-maze test, passive avoidance test, and locomotor activity test were performed. Neurotransmitter levels in the brain were analyzed after the treatment period. Daily oral administration of memantine ameliorated the memory disturbances, anxiety-like behavior, and depression-like behavior observed in TD mice. Memantine did not have a significant effect on monoamine levels, but increased glutamate levels in the hippocampus in TD mice. These results suggest that memantine prevents or suppresses the progression of BPSD-like behaviors that develop due to TD. This effect may be mediated in part by the enhancement of glutamatergic neuron activity in the hippocampus., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: To evaluate the efficacy and safety of fentanyl 1 day patch in opioid-naïve patients with non-cancer chronic pain insufficiently relieved by non-opioid analgesics., Research Design and Methods: Two phase III placebo-controlled, double-blind, group-comparison, randomized withdrawal studies were conducted in patients with osteoarthritis and/or low back pain (N01 study) and post-herpetic neuralgia, complex regional pain syndrome, or chronic postoperative pain (N02) in Japan. Both studies consisted of period I (10-29 days of titration, fentanyl 12.5-50.0 µg/h) and period II (12 weeks double-blind)., Clinical Trial Registration: N01, NCT01008618; N02, NCT01008553 MAIN OUTCOME MEASURES: The primary endpoint was the number of days until study discontinuation due to insufficient pain relief in period II, and secondary endpoints included pain scored on visual analog scale (VAS), subject's overall assessment, the number of rescue dose, brief pain inventory short form score, score on short-form 36-item health survey version 2.0, physician's overall assessment, and assessment of adverse events., Results: Of the 218 (N01) and 258 (N02) subjects who entered period I, 150 and 163 subjects entered period II, respectively. In the N01 study, the between-group difference was significant in the VAS score (95% CI: 7.3 [1.1, 13.5] mm, P = 0.0215) but not in the primary endpoint (P = 0.0846, log-rank test). In the N02 study, both primary efficacy (P = 0.0003) and VAS (8.7 [2.4, 15.0] mm, P = 0.0071) results showed that fentanyl was more effective than placebo. The major adverse events were nervous system and gastrointestinal disorders typically associated with opioid analgesic use. The incidence of adverse events in the fentanyl group was 68.5% to 85.7%., Conclusions: Although the primary efficacy results showed significant effects of fentanyl in the N02 but not the N01 study, overall results showed that fentanyl 1 day patch is effective and well tolerated.

The reduction of brain amyloid beta (Aβ) peptides by anti-Aβ antibodies is one of the possible therapies for Alzheimer's disease. We previously reported that the Aβ peptide vaccine including the T-cell epitope of diphtheria-tetanus combined toxoid (DT) induced anti-Aβ antibodies, and the prior immunization with conventional DT vaccine enhanced the immunogenicity of the peptide. Cynomolgus monkeys were given the peptide vaccine subcutaneously in combination with the prior DT vaccination. Vaccination with a similar regimen was also performed on guinea pigs. The peptide vaccine induced anti-Aβ antibodies in cynomolgus monkeys and guinea pigs without chemical adjuvants, and excessive immune responses were not observed. Those antibodies could preferentially recognize Aβ 40, and Aβ 42 compared to Aβ fibrils. The levels of serum anti-Aβ antibodies and plasma Aβ peptides increased in both animals and decreased the brain Aβ 40 level of guinea pigs. The peptide vaccine could induce a similar binding profile of anti-Aβ antibodies in cynomolgus monkeys and guinea pigs. The peptide vaccination could be expected to reduce the brain Aβ peptides and their toxic effects via clearance of Aβ peptides by generated antibodies.

Objectives: To evaluate the safety and efficacy of osmotic-controlled release oral delivery system (OROS) methylphenidate (MPH) HCl in adults with attention-deficit/hyperactivity disorder (ADHD)., Methods: In this study, 284 adults with ADHD were randomized to OROS MPH or placebo. During the 4-week titration period, patients were titrated from a starting dose of 18 mg once daily to an individually-optimized dose of up to 72 mg once daily in weekly 18-mg increments. Patients continued on their individualized dose during the 4-week efficacy assessment period. The primary efficacy endpoint was change in DSM-IV Total ADHD Symptoms subscale score of Conners' Adult ADHD Rating Scale-Observer: Screening Version (CAARS-O:SV) from baseline to endpoint., Results: The mean change in DSM-IV Total ADHD Symptoms subscale score of CAARS-O:SV was significantly larger with OROS MPH compared with placebo (P < 0.0001, ANCOVA). Similar results were observed for the majority of secondary endpoints, including CAARS-O:SV total score and other subscale scores. Although treatment-emergent adverse events were reported more frequently in the OROS MPH group (81.8%) versus the placebo group (53.9%), OROS-MPH showed a well-tolerated safety profile overall., Conclusions: OROS MPH in a dose range of 18-72 mg once daily was effective and well-tolerated in adult patients with ADHD.

Didecyldimethylammonium chloride (DDAC) is a representative dialkyl-quaternary ammonium compound that is used as a disinfectant against several pathogens and is also used in commercial, industrial, and residential settings. We previously investigated toxicity on air way system following single instillation of DDAC to the lungs in mice, and found that DDAC causes pulmonary injury, which is associated with altered antioxidant antimicrobial responses; the inflammatory phase is accompanied or followed by fibrotic response. The present study was conducted to monitor transforming growth factor-β (TGF-β) signaling in pulmonary fibrosis induced by DDAC. Mice were intratracheally instilled with DDAC and sacrificed 1, 3, or 7 days after treatment to measure TGF-β signaling. In order to further evaluate TGF-β signaling, we treated isolated mouse lung fibroblasts with DDAC. Fibrotic foci were observed in the lungs on day 3, and were widely extended on day 7, with evidence of increased α-smooth muscle actin-positive mesenchymal cells and upregulation of Type I procollagen mRNA. Developing fibrotic foci were likely associated with increased expression of Tgf-β1 mRNA, in addition to decreased expression of Bone morphogenetic protein-7 mRNA. In fibrotic lung samples, the expression of phosphorylated SMAD2/3 was considerably higher than that of phosphorylated SMAD1/5. In isolated lung fibroblasts, the mRNA levels of Tgf-β1 were specifically increased by DDAC treatment, which prolonged phosphorylation of SMAD2/3. These effects were abolished by treatment with SD208 - a TGF-βRI kinase inhibitor. The results suggest that DDAC induces pulmonary fibrosis in association with TGF-β signaling., (Copyright © 2013 Elsevier GmbH. All rights reserved.)

We report a biphasic malignant mesothelioma in an aged female F344/DuCrlCrlj rat. Macroscopically, multiple pale brown nodules were observed in the abdominal cavity with retention of bloody ascites. Histopathologically, the tumor cells spread over the peritoneum and formed masses on the surface and underlying adipose tissues. The tumor cells dominantly proliferated in a solid, nodular or nest-like pattern with modest amount of fibrillar connective tissues, which contained hyaluronan. The tumor consisted of ovoid, polygonal or spindle-shaped cells that possessed eosinophilic cytoplasms including glycogen; some tumor cells showed a signet-ring-like structure. Multinucleated cells and mitosis were found frequently, and direct invasion to intra-abdominal organs and intravascular metastasis to the liver were observed. Immunohistochemically, keratin and mesothelin were strongly positive in most of tumor cells, while vimentin was mainly positive in spindle-shaped cells. Podoplanin was also positive, particularly in the cell membrane of tumor cells. Electron microscopically, tumor cells showed an intercellular desmosome-like structure, basement membrane and microvillus. We diagnosed the case as a malignant peritoneal mesothelioma with a sarcomatoid growth pattern and signet-ring-like structure.

Several types of pesticides, including organochlorines, are known to suppress or modulate immune responses. The present study evaluated the immunotoxicity of the organochlorine pesticide methoxychlor (MXC) in female BALB/c, C3H/He, and ICR mice. Mice were given oral MXC doses of 0, 30, 100, and 300 mg/kg each day for 7 consecutive days. On day 4, the mice also received an intravenous injection of sheep red blood cells (SRBC). The splenic plaque-forming cell (PFC) IgM response and the serum anti-SRBC IgM antibody titer were evaluated while splenic lymphocytes were counted by flow cytometry and the spleen underwent histopathological analysis. Significant decreases in IgM PFC responses were seen in BALB/c, C3H/He, and ICR mice that received MXC doses of 100 and 300 mg/kg. Similar changes in serum anti-SRBC IgM antibody titers occurred in three strain mice. Flow cytometric analysis revealed significantly decreased splenic T-cell (CD3+) populations in a dose dependent manner in BALB/c mice, and in the 300 mg/kg of MXC-treated group of C3H/He mice. Germinal center (GC) B-cell (CD19+PNA+) populations were significantly decreased in the 300 mg/kg of MXC-treated groups of all three mouse strains and in the 30 and 100 mg/kg of MXC-treated groups of BALB/c and C3H/He strain mice. Histopathological analysis revealed decreased cellularity of the periarteriolar lymphoid sheath (PALS; T-cell area) and decreased GC development in all three strains of mice treated with 300 mg/kg MXC. These results suggest that MXC has an immune-suppressive effect in mice, and that our protocol may be useful for rapidly detecting immunosuppression induced by environmental chemicals.

Emerging evidence suggests that chronic exposure to DDT and its derivatives is associated with a variety of human disorders such as anemia. The present study demonstrated that p,p'-DDT caused microcystic anemia in a dose-dependent manner (0, 5, 50, and 500 ppm) in the long-term study up to 2 years. To elucidate the mechanism(s) by which p,p'-DDT induces anemia, certain hematological parameters were assessed in rats fed specific doses of p,p'-DDT for 2 weeks, and the effect of lipopolysaccharide on anemia of inflammation was also examined in p,p'-DDT-treated rats. The parameters included the content of hemoglobin per reticulocyte, mean corpuscular volume of reticulocytes and mature erythrocytes, corpuscular hemoglobin concentration mean of mature erythrocytes, and saturation levels of transferrin and iron. During the 2-week treatment period, hypochromic microcytic reticulocytes and hypochromic normocytic mature erythrocytes were observed in p,p'-DDT-treated rats, with no evidence of alteration in plasma iron levels. p,p'-DDT enhanced microcytosis of reticulocytes, as well as mature erythrocytes, which occurred due to severe hypoferremia resulting from anemia of inflammation; however, plasma iron levels were attenuated probably through the inhibition of interleukin-6. Our data suggests that long-term treatment with p,p'-DDT induces microcytic anemia, possibly because of the impairment of iron utility in erythrocytes.

A two-generation reproduction toxicity study was conducted in rats with a reference estrogenic pesticide, methoxychlor, to validate the sensitivity and competency of current guidelines recommended by the United States Environmental Protection Agency; Japanese Ministry of Agriculture, Forestry and Fisheries; and Organisation for Economic Co-operation and Development for predicting reproductive toxicity of the test compound based on estrogenic endocrine disrupting effects. Both sexes of SD rats were exposed to methoxychlor in the diet at concentrations of 0, 10, 500 and 1500 ppm for two successive generations. The present study has successfully detected estrogenic activities and reproductive toxicities of methoxychlor, as well as its systemic toxicity. Body weights, body weight gains and food consumption of both sexes of animals were suppressed significantly in the 500 and 1500 ppm groups. Typical reproductive toxicities observed in females of these groups included, but were not limited to, prolonged estrous cycle, reduced fertility, decreased numbers of implantation sites and newborns, decreased ovary weights and/or increased incidences of cystic ovary. Uterine weights of weanlings increased significantly in these groups, suggesting that the sensitivity of this parameter for predicting estrogenic ability of the test compound is comparable to that of the uterotrophic assay. Reproductive toxicities of methoxychlor seemed less potent in males than in females. Methoxychlor delayed preputial separation and significantly reduced sperm counts and reproductive organ weights of males of the 500 and/or 1500 ppm groups; however, most males that failed to impregnate females in the same group showed normal fertility when they were re-mated with untreated females. Neither systemic nor reproductive toxicities appeared in the 10 ppm group., (© 2011 The Authors. Congenital Anomalies © 2011 Japanese Teratology Society.)

Dimethylarsinic acid (DMA(V)), the major excreted metabolite of inorganic arsenic, is carcinogenic to the rat urinary bladder. Oxidative stress has been proposed as one possible mechanism of DMA(V)-induced carcinogenesis. The authors determined whether the antioxidant N-acetylcysteine (NAC) modifies DMA(V)-induced urinary bladder injury in rats. The treatment solutions--DMA(V) at 10 mg/kg, NAC at 90 or 1.6 mg/kg (high or low dose, respectively), and their combination--were intravesically instilled into female F344 rats over two hours under pentobarbital anesthesia. The treatment was conducted twice with an interval of three days. All animals were euthanized one day after the second treatment. NAC (low dose) alone did not induce histopathological changes or increase 5-bromo-2'-deoxyuridine (BrdU) labeling index in urothelial cells. Both DMA(V) and NAC (high dose) induced a weak neutrophil infiltration and an increase in the BrdU labeling index; these pathological changes were enhanced by the combined treatment of DMA(V) and NAC (high or low dose). Increased oxidative stress and urothelial cell hyperplasia with evidence of activated p44/42 MAPK (ERK1/2) and cyclin D1 were found in the DMA(V) and NAC (high dose) cotreated group. These results suggest that cotreatment with NAC enhanced DMA(V)-induced urinary bladder injury and that the effects may be mediated by excess oxidative stress and ERK signaling.

Didecyldimethylammonium chloride (DDAC), a representative dialkyl-quaternary ammonium compound (QAC), could contaminate working atmospheres when used in disinfectant operation and adversely affect human health. Furthermore, the development of bacteria resistant to DDAC might become public health concern. We postulated that DDAC instillation in the lungs alters pulmonary antioxidant and antimicrobial responses and increases susceptibility to systemic administration of a bacterial component lipopolysaccharide (LPS). Mice were intratracheally instilled with DDAC and sacrificed 1, 3, or 7 days after treatment. Pulmonary cytotoxicity in recovered bronchoalveolar lavage was evident on Days 1 and 7, and inflammatory cell influx and interleukin-6 expression peaked on Day 7, in association with altered antioxidant and antimicrobial responses, as demonstrated by measuring heme oxygenase-1, glutathione peroxidase 2, lactoferrin, and mouse β-defensin-2 and -3 mRNA in the lung samples. The impaired defense system tended to enhance the inflammatory reaction caused by a systemic administration of LPS; the effect was in association with increased expression of toll-like receptor-4 mRNA. The results suggest that DDAC alters pulmonary defense system, which may contribute to susceptibility to an exogenous infectious agent.

Leydig cell tumors with spindle-shaped cells are very rare in humans and animals. We report that an 84-week-old male CD-1 mouse had a malignant Leydig cell tumor characterized by proliferation of oval to spindle-shaped cells with or without fat deposition, and with a storiform pattern. These cells were immunopositive for inhibin and S-100, and negative for the androgen receptor, thereby suggesting that they may have differentiated from Leydig cells. This differentiation from Leydig cells was further confirmed by the immunopositivity of these cells for nestin and alpha-smooth muscle actin, both of which are known to be expressed in the stem/progenitor cells that differentiate into Leydig cells. These findings suggest that the tumor is most probably a malignant spindle-cell-type Leydig cell tumor.

Chromated copper arsenate, which is used worldwide as a wood preservative, can adversely affect human health. Accumulating evidence suggests that chromium (Cr) and arsenic (As) can potentially disrupt the redox balance and cause respiratory diseases and cancer in humans. The present study was designed to determine the combined toxic effects of these metals in the lungs and to clarify the specific molecules that are stimulated by combined exposure to both metals. Male C57BL/6J mice were intratracheally instilled with arsenate [As(V)], hexavalent chromium [Cr(VI)], or a combination of both metals. Mice were sacrificed 2 days after treatment to collect bronchoalveolar lavage fluid and lung tissue samples. Inflammation, cytotoxicity, apoptosis, and oxidative stress markers were measured. Our results indicated that administration of Cr(VI) alone or in combination with As(V) induced neutrophil-dominant inflammation as well as phosphorylation of mitogen-activated protein kinases; effects of treatment with As(V) alone were comparatively less potent. By analyzing the production of interleukin-6 and activity of lactate dehydrogenase and caspase, we confirmed that co-treatment intensified pulmonary injury and that it was accompanied by oxidative stress, as confirmed by marked increases in the production of reactive oxygen species, reduced glutathione content, and thioredoxin reductase (TRXRD) activity. Expressed mRNA levels of heme oxygenase-1, glutamylcysteine ligase, glutathione peroxidase 2, thioredoxin (TRX) 1, and TRXRD1 were also enhanced by co-treatment, whereas treatment with As(V) alone reduced the mRNA expression level of TRX2. Our data suggest that co-treatment with As(V) exacerbated Cr(VI)-induced pulmonary injury and that this effect may be exerted through a disruption in the balance among several antioxidant genes., (2009 Elsevier Ireland Ltd. All rights reserved.)

The in vitro and in vivo antibacterial activities of levofloxacin (LVFX), a quinolone antibacterial, against clinically isolated Legionella pneumophila were investigated in comparison with those of existing antimicrobial agents approved for legionnaires disease. The minimum inhibitory concentrations (MICs) of the agents against 42 strains of L. pneumophila isolated in Japan were determined using agar dilution methods with buffered starch yeast extract agar. MIC90 of LVFX was 0.03 microg/ml and this activity was similar to ciprofloxacin and pazufloxacin, and higher than telithromycin and minocycline. Therapeutic efficacy of LVFX was studied against a pneumonia model induced by intranasal of L. pneumophila strain suzuki serogoup 1 in DBA/2 mice. Therapeutic doses in mice were selected that would closely match human exposure profile, area under the concentration-time curve (AUC) for a human oral dose of LVFX at 500 mg once a day. LVFX decreased significantly the bacterial burden in the lungs from the next day of commencing treatment. These results, including in vitro antibacterial activity against clinical isolates and therapeutic efficacy of a humanized dosing regimen, provide good evidence to support the use of LVFX at 500 mg once a day for treating patient with legionnaires disease.

We present here a new model of Legionella pneumophila lung infection in DBA/2 mice. By intranasal inoculation with 106 colony-forming units of L. pneumophila strain suzuki serogoup 1, persistent non-lethal lung infection was established as reflected by the detection of more than 10(4) CFU/lung of the organism 14 days after infection. Treatment of mice with cyclophosphamide before infection enhanced bacterial replication in the lungs and all cyclophosphamide-treated mice experienced lethal infection. Histopathologically, the course of non-lethal lung infection was characterized by early response of neutrophiles, then monocyte/macrophages response in the alveoli with disease progression, and diffuse alveolar wall thickening with lymphocyte migration at later phase of infection. Transmission electron microscopic evaluation of the lungs confirmed that L. pneumophila located intracellularly within neutrophiles and infrequently intracellular bacteria were observed undergoing binary fission. Therefore, the mouse model of replicative L. pneumophila lung infection provides method for evaluating pathogenesis of L. pneumophila lung infection and antibacterial therapy.

Rho GTPases play an essential role in the regulation of many cellular processes. Although various guanine nucleotide exchange factors (GEFs) are involved in the activation of Rho GTPases, the precise mechanism regulating such activity remains unclear. We have examined whether ERK1/2 are involved in the phosphorylation of GEF-H1, a GEF toward RhoA, to modulate its activity. Expression of GEF-H1 in HT1080 cells with constitutive ERK1/2 activation induced its phosphorylation at Thr(678), which was totally abolished by treating the cells with PD184352, an ERK pathway inhibitor. Stimulation of HeLa S3 cells with 12-O-tetradecanoyl-phorbol-13-acetate induced the phosphorylation of GEF-H1 in an ERK-dependent manner. ERK1/2-mediated Thr(678)-phosphorylation enhanced the guanine nucleotide exchange activity of GEF-H1 toward RhoA. These results suggest that the ERK pathway, by enhancing the GEF-H1 activity, contributes to the activation of RhoA to regulate the actin assembly, a necessary event for the induction of cellular responses including proliferation and motility.

DC-159a is a new 8-methoxy fluoroquinolone that possesses a broad spectrum of antibacterial activity, with extended activity against gram-positive pathogens, especially streptococci and staphylococci from patients with community-acquired infections. DC-159a showed activity against Streptococcus spp. (MIC(90), 0.12 microg/ml) and inhibited the growth of 90% of levofloxacin-intermediate and -resistant strains at 1 microg/ml. The MIC 90s of DC-159a against Staphylococcus spp. were 0.5 microg/ml or less. Against quinolone- and methicillin-resistant Staphylococcus aureus strains, however, the MIC 90 of DC-159a was 8 microg/ml. DC-159a was the most active against Enterococcus spp. (MIC 90, 4 to 8 microg/ml) and was more active than the marketed fluoroquinolones, such as levofloxacin, ciprofloxacin, and moxifloxacin. The MIC 90s of DC-159a against Haemophilus influenzae, Moraxella catarrhalis, and Klebsiella pneumoniae were 0.015, 0.06, and 0.25 microg/ml, respectively. The activity of DC-159a against Mycoplasma pneumoniae was eightfold more potent than that of levofloxacin. The MICs of DC-159a against Chlamydophila pneumoniae were comparable to those of moxifloxacin, and DC-159a was more potent than levofloxacin. The MIC 90s of DC-159a against Peptostreptococcus spp., Clostridium difficile, and Bacteroides fragilis were 0.5, 4, and 2 microg/ml, respectively; and among the quinolones tested it showed the highest level of activity against anaerobic organisms. DC-159a demonstrated rapid bactericidal activity against quinolone-resistant Streptococcus pneumoniae strains both in vitro and in vivo. In vitro, DC-159a showed faster killing than moxifloxacin and garenoxacin. The bactericidal activity of DC-159a in a murine muscle infection model was revealed to be superior to that of moxifloxacin. These activities carried over to the in vivo efficacy in the murine pneumonia model, in which treatment with DC-159a led to bactericidal activity superior to those of the other agents tested.

Testosterone propionate (TP) was supplemented to male rats for assessment of its ameliorating effect on testicular toxicity with thiamphenicol (TAP). A total of 20 male Sprague-Dawley rats were treated orally with TAP at 200 mg/kg/day for up to 4 weeks. In addition, 5 male rats were allotted to the control group receiving vehicle only. Ten of the 20 treated rats had a Silastic capsule (containing about 80 mg of TP) implanted in the dorsal skin at Week 2 and assigned to the TAP-TP group, while the other 10 treated rats were in the TAP group. After Weeks 3 and 4, five of both treated groups were examined for weight and histology of the testis and accessory genital glands, and for staging analysis of the seminiferous tubules. The same parameters were also assessed in the control group after Week 4. Weights and morphology of the seminal vesicle and prostate recovered remarkably from the TAP toxicity after TP supplement. However, no ameliorating effects of TP were obtained for the testis in either weight, morphology, or staging analysis of the seminiferous tubules.

To delineate morphological characteristics of olfactory lesions induced by vincristine (VCR), a vinca alkaloid derivative with antitumor activity, male BALB/c mice were given a single intravenous injection of 1.95 mg/kg, an estimated 10% lethal dose (designated as day 1). The animals were serially sacrificed on days 2, 3, 5, 10, 15 and 60, and the nasal mucosa was examined histopathologically. Cell death was noted in the olfactory epithelia adjacent to the respiratory epithelia from days 2 to 5. Inflammatory responses were not detected throughout the observation periods. Cell death was identified as apoptotic by the terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling (TUNEL) assay and electron microscopy. Mitotic figures and proliferating cell nuclear antigen (PCNA)-positive reactions were diffusely scattered in both the basal and sensory cells. On days 10 or after, no prominent histological abnormalities were noted in the olfactory epithelia, which suggests the aforementioned lesions were completely recovered. These results demonstrate that it is essential to perform histopathological evaluation of the nasal mucosa during an early preclinical stage for novel antitumor drugs, since olfactory lesions due to the certain compounds like VCR may not be detected by any other procedure.

To characterize and compare maxillary incisor lesions caused by various antitumor drugs, male BALB/c mice were given a single intravenous injection of an estimated 10% lethal dose (LD10)) of 5-fluorouracil (5-FU), adriamycin (ADR), mitomycin C (MMC), vinblastine sulfate (VBL). taxotere (TXR), irinotecan hydrochloride (CPT-11), DX-8951f, or cisplatin (CDDP). After 3, 5, 10, 15, and 60 days, the animals were sacrificed, and the maxillary incisors were examined microscopically. The dental lesions observed were classified into 4 different types on the basis of their morphological features. The lesion due to 5-FU was characterized by focal defects in the dentin, and this injury was reversible (transient dentin injury). ADR- or MMC-induced lesions were defined by abnormal structure of the apical aspect of the tooth and irregular odontogenesis, lasting for a long period (persistent apical injury). Treatment with VBL or TXR showed irregular enamel formation and abnormal dentinogenesis. Their targets were considered to be both immature and mature odontogenic cells (diffuse dental injury). Exposure to CPT-11, DX-8951f, or CDDP elicited minor reductions in a few precursor cells in the epithelial sheath on day 3, but no prominent dental abnormalities were seen thereafter (nontoxic injury). In conclusion, antitumor drugs can cause a variety of dental lesions that vary temporally and spatially, making histopathological examination of the maxillary incisor an important component of the safety assessment process for novel antitumor drugs.

Two spontaneous tumours in the hind leg of 2 aged Mastomys were diagnosed as poorly differentiated rhabdomyosarcomas. In both cases, the neoplastic cells had no evidence of cross-striation, but had a positive reaction for muscle-specific proteins. This is the second report of rhabdomyosarcomas in Mastomys, and the first described in detail.