Circulatory efficiency in patients with severe aortic valve stenosis before and after aortic valve replacement.

BACKGROUND: Circulatory efficiency reflects the ratio between total left ventricular work and the work required for maintaining cardiovascular circulation. The effect of severe aortic valve stenosis (AS) and aortic valve replacement (AVR) on left ventricular/circulatory mechanical power and efficiency is not yet fully understood. We aimed to quantify left ventricular (LV) efficiency in patients with severe AS before and after surgical AVR. METHODS: Circulatory efficiency was computed from cardiovascular magnetic resonance (CMR) imaging derived volumetric data, echocardiographic and clinical data in patients with severe AS (n = 41) before and 4 months after AVR and in age and sex-matched healthy subjects (n = 10). RESULTS: In patients with AS circulatory efficiency was significantly decreased compared to healthy subjects (9 ± 3% vs 12 ± 2%; p = 0.004). There were significant negative correlations between circulatory efficiency and LV myocardial mass (r = - 0.591, p < 0.001), myocardial fibrosis volume (r = - 0.427, p = 0.015), end systolic volume (r = - 0.609, p < 0.001) and NT-proBNP (r = - 0.444, p = 0.009) and significant positive correlation between circulatory efficiency and LV ejection fraction (r = 0.704, p < 0.001). After AVR, circulatory efficiency increased significantly in the total cohort (9 ± 3 vs 13 ± 5%; p < 0.001). However, in 10/41 (24%) patients, circulatory efficiency remained below 10% after AVR and, thus, did not restore to normal values. These patients also showed less reduction in myocardial fibrosis volume compared to patients with restored circulatory efficiency after AVR. CONCLUSION: In our cohort, circulatory efficiency is reduced in patients with severe AS. In 76% of cases, AVR leads to normalization of circulatory efficiency. However, in 24% of patients, circulatory efficiency remained below normal values even after successful AVR. In these patients also less regression of myocardial fibrosis volume was seen. Trial Registration clinicaltrials.gov NCT03172338, June 1, 2017, retrospectively registered.

Phase Ib study of atezolizumab combined with cobimetinib in patients with solid tumors.

BACKGROUND: Preclinical evidence suggests that MEK inhibition promotes accumulation and survival of intratumoral tumor-specific T cells and can synergize with immune checkpoint inhibition. We investigated the safety and clinical activity of combining a MEK inhibitor, cobimetinib, and a programmed cell death 1 ligand 1 (PD-L1) inhibitor, atezolizumab, in patients with solid tumors. PATIENTS AND METHODS: This phase I/Ib study treated PD-L1/PD-1-naive patients with solid tumors in a dose-escalation stage and then in multiple, indication-specific dose-expansion cohorts. In most patients, cobimetinib was dosed once daily orally for 21 days on, 7 days off. Atezolizumab was dosed at 800 mg intravenously every 2 weeks. The primary objectives were safety and tolerability. Secondary end points included objective response rate, progression-free survival, and overall survival. RESULTS: Between 27 December 2013 and 9 May 2016, 152 patients were enrolled. As of 4 September 2017, 150 patients received ≥1 dose of atezolizumab, including 14 in the dose-escalation cohorts and 136 in the dose-expansion cohorts. Patients had metastatic colorectal cancer (mCRC; n = 84), melanoma (n = 22), non-small-cell lung cancer (NSCLC; n = 28), and other solid tumors (n = 16). The most common all-grade treatment-related adverse events (AEs) were diarrhea (67%), rash (48%), and fatigue (40%), similar to those with single-agent cobimetinib and atezolizumab. One (<1%) treatment-related grade 5 AE occurred (sepsis). Forty-five (30%) and 23 patients (15%) had AEs that led to discontinuation of cobimetinib and atezolizumab, respectively. Confirmed responses were observed in 7 of 84 patients (8%) with mCRC (6 responders were microsatellite low/stable, 1 was microsatellite instable), 9 of 22 patients (41%) with melanoma, and 5 of 28 patients (18%) with NSCLC. Clinical activity was independent of KRAS/BRAF status across diseases. CONCLUSIONS: Atezolizumab plus cobimetinib had manageable safety and clinical activity irrespective of KRAS/BRAF status. Although potential synergistic activity was seen in mCRC, this was not confirmed in a subsequent phase III study. CLINICALTRIALS.GOV IDENTIFIER: NCT01988896 (the investigators in the NCT01988896 study are listed in the supplementary Appendix, available at Annals of Oncology online).

Recurrence rates of cutaneous squamous cell carcinoma of the head and neck after Mohs micrographic surgery vs. standard excision: a retrospective cohort study.

BACKGROUND: Recurrent cutaneous squamous cell carcinoma (cSCC) has been associated with an increased risk of local functional and aesthetic comorbidity, metastasis and mortality. OBJECTIVES: To compare the risk of recurrence between Mohs micrographic surgery (MMS) and standard excision for cSCC of the head and neck. METHODS: This was a retrospective cohort study of all patients with a cSCC treated with MMS or standard excision at the departments of dermatology of a secondary or tertiary care hospital in the Netherlands between 2003 and 2012. To detect all recurrences, patients were linked to the Dutch pathology registry. To compare the risk of recurrence between MMS and standard excision, hazard ratios (HRs) were used adjusted for clinical tumour size > 2 cm and deep tumour invasion. RESULTS: A total of 579 patients with 672 cSCCs were included: 380 cSCCs were treated with MMS and 292 with standard excision. The risk of recurrence was 8% (22 of 292) after standard excision during a median follow-up of 5·7 years [interquartile range (IQR) 3·5-7·8], which was higher than the 3% (12 of 380) after MMS during a median follow-up of 4·9 years (IQR 2·3-6·0). The cumulative incidence of recurrence was higher for standard excision than for MMS during the entire follow-up period of 8·6 years. Carcinomas treated with MMS were at a three times lower risk of recurrence than those treated with standard excision when adjusted for tumour size and deep tumour invasion (adjusted HR 0·31, 95% confidence interval 0·12-0·66). CONCLUSIONS: MMS might be superior to standard excision for cSCCs of the head and neck because of a lower rate of recurrence.

Morbidity and mortality resulting from acute inhalation exposures to hydrogen fluoride and carbonyl fluoride in rats.

OBJECTIVE: Experiments were undertaken to compare morbidity and mortality from brief inhalation exposures to high levels of hydrogen fluoride (HF) and carbonyl fluoride (COF2). METHODS: Rats from both sexes were exposed for durations of 5 and 10 min to nominal concentrations of 10,000 to 57,000 ppm HF or 500 to 10,000 ppm COF2. Respiration was monitored before, during, and after exposure. Animals were observed up to 6 days post-exposure. Terminal blood samples were collected for routine clinical chemistry and hematology. Post-mortem lung fluoride concentrations and lung weights were measured, and gross pathology noted. RESULTS: Both gases produced respiratory depression independent of concentration or exposure duration with minute ventilation decreasing to approximately 50% of baseline. Estimated mixed-gender HF and COF2 10-min LC50's were 48,661 ppm and 1083 ppm, respectively. HF mortalities were generally delayed 3 to 4 days post-exposure, while COF2 mortalities occurred during or briefly after exposure. Lung fluoride levels increased with COF2 dose, though elevated lung weights occurred only at the mid-level exposures. Lung weights were unaffected in the HF-exposed animals, and their lung fluoride concentrations were variable. Clinical chemistry and hematology had few consistent trends with the exception of hemoconcentration primarily in HF-exposed males. These short-term exposure experiments conclude that COF2 is nearly 45 times more lethal than HF in rats. CONCLUSIONS: These experiments suggest that hydrolysis to HF cannot solely explain COF2 toxicity. Although HF and COF2 may have common injury mechanisms, they are expressed to markedly different degrees and temporal occurrence.

Acute and subacute oral toxicity of periodate salts in rats.

Periodate salts are being developed as potential replacements for perchlorate due to potential health hazards associated with exposure to perchlorate. The aim of this study was to investigate acute and subacute effects of periodate salts in rats. Acute oral toxicity of potassium and sodium periodate was determined using the Sequential Stage-Wise Probit method. The LD50 for potassium periodate was 732 (95% CI = 539-838, slope = 13.4) and 685 mg/kg (95% CI = 580-809, slope = 10.6) for females and males, respectively. The LD50 for sodium periodate was 318 (95% CI = 292-347, slope = 24.3) and 741 mg/kg (95% CI = 704-779, slope = 31.2) for females and males, respectively. In the subacute study, rats were administered sodium periodate at five doses (1/16 LD50 up to LD50) or distilled water for 14-days via oral gavage. Female rats in the 318 mg/kg-day group and male rats in the 185, 370, and 741 mg/kg-day groups exhibited moribundity, kidney toxicity, uremia, and a stress response. BMDL10s of 17.2 and 33.7 mg/kg-day were derived for females and males, respectively. Comparison with the NOAEL for perchlorate-induced thyroid toxicity in rats (0.009 mg/kg-day) suggests sodium periodate is less toxic than perchlorate on a subacute basis.

Mohs micrographic surgery of rare cutaneous tumours.

BACKGROUND: Recurrence rates after Mohs micrographic surgery (MMS) for rare cutaneous tumours are poorly defined. OBJECTIVE: To investigate the recurrence rate after MMS for rare cutaneous tumours at a university centre. METHODS & MATERIALS: Retrospective review of all rare cutaneous tumours treated with MMS at a large university centre between January 2008 and December 2012. To detect all recurrences, patients were linked to The Nationwide Network and registry of histo- and cytopathology (PALGA). RESULTS: In total, 80 patients with 80 tumours were included. Tumour types included dermatofibrosarcoma protuberans (27), atypical fibroxanthoma (22), Merkel cell carcinoma (8), microcystic adnexal carcinoma (9), sebaceous carcinoma (6), extramammary Paget's disease (2) and other (6). Mean follow-up time was 3.7 years (standard deviation 1.4) during which two atypical fibroxanthomas recurred (2.5%). CONCLUSION: This large case series shows that MMS is an appropriate treatment for rare cutaneous tumours with a recurrence rate less than 3%. Preferably, MMS for rare cutaneous tumours is performed in experienced multidisciplinary centres to further improve the quality of treatment.

An extended one-generation reproductive toxicity test of 1,2,4-Triazol-5-one (NTO) in rats.

Nitrotriazolone (1,2,4-triazol-5-one; NTO), an insensitive, energetic material used in explosive formulations, induced testicular toxicity and oligospermia in repeated-dose oral toxicity tests in rats. To evaluate whether NTO produces additional reproductive and developmental effects, a modified extended one-generation reproductive toxicity test was conducted. Rats were provided ad libitum access to NTO in drinking water at 0-, 144-, 720-, or 3600-mg/L NTO. Treatment of the parental generation began 2 (females) and 4 (males) wk premating and continued until weaning of litters. Direct dosing of offspring (F1) occurred from weaning through puberty. Pups were counted and weighed on postnatal day (PND) 0/1. Anogenital distance (AGD) was measured on PND 4 and males were examined for presence of nipples on PND 13. F1 offspring were examined daily for attainment of puberty. NTO did not markedly affect measures of fertility, including mating indices, gestation index, litter size, and sex ratio. Seminiferous tubule degeneration or atrophy was observed in P1 and F1 3600-mg/L NTO males. F1 males in the 3600 mg/L group exhibited reduced reproductive organ mass (testes, epididymides, and accessory sex organs). Nipple retention was increased in NTO exposed F1 males compared to controls. Attainment of puberty was delayed by 2.6 d in the 3600-mg/L NTO-exposed males relative to controls. Comparison of the effects of NTO with those of antiandrogens suggests absence of malformations of the genital tract in NTO-exposed males. This study supports previous findings indicating that NTO is a testicular toxicant with male developmental effects that may be secondary to testicular toxicity.

Oral Toxicity of 2,4-Dinitroanisole in Rats.

Subacute and subchronic studies were conducted to assess the toxicity of 2,4-dinitroanisole (DNAN) and to provide information important for protecting the health of military and civilian personnel. In the subchronic study, male and female Sprague-Dawley rats were dosed with DNAN via oral gavage at 0, 1.25, 5, 20, and 80 mg/kg/d. Likely owing to its conversion to 2,4-dinitrophenol, an inhibitor of energy homeostasis, DNAN caused an apparent increase in metabolism, leading to reduced feed efficiency ratios and body mass gains in males. Anemia, splenic enlargement, hemosiderosis, and extramedullary hematopoiesis indicated blood as a target organ, with females more sensitive than males. The DNAN was a testicular toxicant, causing decreased mass of testes and epididymides, as well as degeneration and atrophy of testicular seminiferous tubules and epididymal aspermia. Stereotypical behavior in males, gait irregularities, and cerebellar lesions indicated that DNAN is neurotoxic. Splenic enlargement, anemia, testicular toxicity, and neurotoxicity occurred only at or near lethal doses in the subchronic study.

A phase Ib dose-escalation study of the MEK inhibitor trametinib in combination with the PI3K/mTOR inhibitor GSK2126458 in patients with advanced solid tumors.

Introduction This Phase Ib trial investigated the safety, tolerability, and recommended phase 2 dose for the pan-PI3K/mTOR inhibitor, GSK2126458 (GSK458), and trametinib combination when administered to patients with advanced solid tumors. Patients and Methods Patients with advanced solid tumors received escalating doses of GSK458 (once or twice daily, and continuous or intermittent) and trametinib following a zone-based 3 + 3 design to determine the maximum tolerated dose (MTD). Assessments included monitoring for adverse events and response, and evaluating pharmacokinetic (PK) measures. Archival tissue and circulating free DNA samples were collected to assess biomarkers of response in the PI3K and RAS pathways. Results 57 patients were enrolled onto the continuous dosing cohort and 12 patients onto an intermittent BID dosing cohort. Two MTDs were established for the continuous daily dosing: 2 mg of GSK458 with 1.0 mg of trametinib or 1.0 mg of GSK458 with 1.5 mg of trametinib; no MTD was determined in the intermittent dosing cohort. The most frequent adverse events were rash (74 %) and diarrhea (61 %). Dose interruptions due to adverse events occurred in 42 % of patients. No significant PK interaction was observed. One patient achieved partial response and 12 patients had stable disease >16 weeks. Mutations in RAS/RAF/PI3K were detected in 70 % of patients, but no pattern emerged between response and mutational status. Conclusion GSK458 plus trametinib is poorly tolerated, due to skin and GI-related toxicities. Responses were minimal, despite enrichment for PI3K/RAS pathway driven tumors, which may be due to overlapping toxicities precluding sufficient dose exposure.

Reliability of diagnosis from Mohs slides: interpersonal and intrapersonal agreement on basal cell carcinoma presence and histological subtype.

BACKGROUND: The success of Mohs micrographic surgery (MMS) depends partly on the correct diagnosis of slides. OBJECTIVES: To determine reliability of diagnosis from Mohs slides. METHODS: This was a prospective study evaluating the reliability of diagnosis from Mohs slides of basal cell carcinoma (BCC) presence, BCC location on the slide and BCC subtype among six raters who independently assessed 50 Mohs slides twice with a 2-month interval. Slides were randomly selected whereby difficult-to-diagnose slides were oversampled. For each slide, a reference diagnosis was established by an expert panel. Cohen's kappa (κ) was calculated to determine levels of agreement interpersonally (rater vs. reference diagnosis) and intrapersonally (rater at T1 vs. T2). Multivariable logistic regression was used to determine independent risk factors for slides with interpersonal discordant diagnosis. The variables studied were BCC presence, whether a slide was scored as easy or difficult to diagnose, review duration of the 50 slides, profession and years of experience in diagnosis from Mohs slides. RESULTS: Interpersonal and intrapersonal agreement were substantial on BCC presence (κ = 0·66 and 0·68) and moderate on BCC subtype (κ = 0·45 and 0·55). Slides that were scored as difficult to diagnose were an independent risk factor for interpersonal discordant diagnosis on BCC presence (odds ratio 3·54, 95% confidence interval 1·81-6·84). CONCLUSIONS: Reliability of diagnosis from Mohs slides was substantial on BCC presence and moderate on BCC subtype. For slides that are scored difficult to diagnose, a second opinion is recommended to prevent misinterpretation and thereby recurrence of skin cancer.

Efficacy and safety of teneligliptin, a novel dipeptidyl peptidase-4 inhibitor, in Korean patients with type 2 diabetes mellitus: a 24-week multicentre, randomized, double-blind, placebo-controlled phase III trial.

We assessed the 24-week efficacy and safety of teneligliptin, a novel dipeptidyl peptidase-4 inhibitor, in Korean patients with type 2 diabetes mellitus (T2DM) that was inadequately controlled with diet and exercise. The present study was designed as a multicentre, randomized, double-blind, placebo-controlled, parallel-group, phase III study. Patients (n = 142) were randomized 2 : 1 into two different treatment groups as follows: 99 received teneligliptin (20 mg) and 43 received placebo. The primary endpoint was change in glycated haemoglobin (HbA1c) level from baseline to week 24. Teneligliptin significantly reduced the HbA1c level from baseline compared with placebo after 24 weeks. At week 24, the differences between changes in HbA1c and fasting plasma glucose (FBG) in the teneligliptin and placebo groups were -0.94% [least-squares (LS) mean -1.22, -0.65] and -1.21 mmol/l (-1.72, -0.70), respectively (all p < 0.001). The incidence of hypoglycaemia and adverse events were not significantly different between the two groups. This phase III, randomized, placebo-controlled study provides evidence of the safety and efficacy of 24 weeks of treatment with teneligliptin as a monotherapy in Korean patients with T2DM.

Peri-pubertal administration of 3-nitro-1,2,4-triazol-5-one (NTO) affects reproductive organ development in male but not female Sprague Dawley rats.

Nitrotriazolone (3-nitro-1,2,4-triazol-5-one; NTO) is an insensitive munition that has demonstrated effects on reproductive organs in adult male rats. NTO was administered to male (0, 250, and 500milligrams per kilogram per day (mg/kg-day)) and female (0, 500, and 1000mg/kg-day) Sprague-Dawley rats (15/sex/group) via oral gavage from weaning through post-natal day 53/54 and 42/43, respectively. Age and body mass at vaginal opening (VO) and preputial separation (PPS), as well as all measures of estrous cyclicity were not affected by treatment with NTO. Males treated with NTO exhibited reductions in testis mass associated with tubular degeneration/atrophy. Less pronounced reductions in accessory sex organ masses were also observed in the 500mg/kg-day group. Treatment with NTO did not affect thyroid hormone or testosterone levels. These findings suggest that NTO is not acting as an estrogen or thyroid active compound, but may indicate effects on steroidogenesis and/or direct testicular toxicity.

Subchronic Oral Toxicity of Sodium Tungstate in Sprague-Dawley Rats.

The subchronic toxicity of sodium tungstate dihydrate aqueous solution in male and female Sprague-Dawley rats was evaluated by daily oral gavage of 0, 10, 75, 125, or 200 mg/kg/d for 90 days. Measured parameters included food consumption, body weight measurements, hematology, clinical chemistry, and histopathological changes. There was a significant decrease in food consumption and body weight gain in males at 200 mg/kg/d from days 77 to 90; however, there was no effect in food consumption and body weights in females. There were no changes in the hematological and clinical parameters studied. Histopathological changes were seen in kidney of male and female and epididymis of male rats. Histopathological changes were observed in the kidneys of male and female rats dosed at 125 or 200 mg/k/d consisting of mild to severe cortical tubule basophilia in 2 high-dose groups. Histological changes in epididymides included intraluminal hypospermia with cell debris in the 200 mg/kg/d dosed male rats. Histopathological changes were observed in the glandular stomach including inflammation and metaplasia in the high-dose groups (125 or 200 mg/kg/d) of both sexes of rats. Based on histopathology effects seen in the kidneys, the lowest observable adverse effect level was 125 mg/kg/d and the no observable adverse effect level was 75 mg/kg/d in both sexes of rats for oral subchronic toxicity.

Additional review of Mohs slides to optimize Mohs micrographic surgery.

BACKGROUND: One significant risk factor for recurrence after Mohs surgery is misinterpretation of slides. OBJECTIVES: To determine how often pathologists detected incompletely excised basal cell carcinoma (BCC) on Mohs slides and to determine risk factors for incompletely excised BCCs. METHODS: This retrospective study included 1653 BCCs treated with Mohs surgery in a university hospital between 2007 and 2011. For routine quality assurance, all slides were additionally reviewed by a pathologist within 1 week of the procedure. For this study, all cases that had divergent interpretations were re-evaluated by a Mohs surgeon and a pathologist. Mixed-effects logistic regression models with Mohs surgeon effects as random effects were used to determine risk factors for incompletely excised BCC. RESULTS: Incompletely excised BCCs were detected in 31 cases (2%), in which defects > 20 mm in diameter were an independent risk factor (odds ratio 3.58, 95% confidence interval 1.55-8.28). Other studied variables (i.e. aggressive subtype, previously treated BCC, location on nose and > 2 Mohs stages) did not affect the risk of incompletely excised BCCs. CONCLUSIONS: The additional review of Mohs slides might increase accurate interpretation, especially in large BCCs.

Oral toxicity of 3-nitro-1,2,4-triazol-5-one in rats.

3-Nitro-1,2,4-triazol-5-one (NTO), an insensitive explosive, was evaluated to assess potential environmental and human health effects. A 14-day oral toxicity study in Sprague-Dawley rats was conducted with NTO in polyethylene glycol -200 by gavage at doses of 0, 250, 500, 1000, 1500, or 2000 mg/kg-d. Body mass and food consumption decreased in males (2000 mg/kg-d), and testes mass was reduced at doses of 500 mg/kg-d and greater. Based on the findings in the 14-day study, a 90-day study was conducted at doses of 0, 30, 100, 315, or 1000 mg/kg-d NTO. There was no effect on food consumption, body mass, or neurobehavioral parameters. Males in the 315 and 1000 mg/kg-d groups had reduced testes mass with associated tubular degeneration and atrophy. The testicular effects were the most sensitive adverse effect and were used to derive a benchmark dose (BMD) of 70 mg/kg-d with a 10% effect level (BMDL10) of 40 mg/kg-d.

Comparison of the repeated dose toxicity of isomers of dinitrotoluene.

Dinitrotoluene (DNT) is a nitroaromatic explosive used in propellant mixtures and in the production of plastics. Isomers of DNT were administered daily via oral gavage to male Sprague-Dawley rats for 14 days to determine the subacute toxicity of individual isomers of DNT. The 3,5-DNT isomer was the most toxic isomer, inducing weight loss and mortality within 3 days. Cyanosis and anemia were observed for all isomers. Exposure to 2,4-, 2,6-, and 3,5-DNT resulted in decreased testes mass and degenerative histopathological changes. Increased splenic mass was observed for 2,4-, 2,6-, and 2,5-DNT. Extramedullary hematopoiesis of the spleen was noted for all isomers, while lymphoid hyperplasia of the spleen was noted for all isomers except 2,5-DNT. Increased liver mass was observed for 2,3-DNT and 3,4-DNT. Hepatocellular lesions were observed for 2,6-DNT and 2,4-DNT. Neurotoxic effects were noted for 3,4-DNT, 2,4-DNT, and 3,5-DNT.

Assessment of the in vivo genotoxicity of isomers of dinitrotoluene using the alkaline Comet and peripheral blood micronucleus assays.

Dinitrotoluene (DNT) is a nitroaromatic explosive that exists as six isomers; two major isomers (2,4- and 2,6-DNT) and four minor isomers (2,3-, 2,5-, 3,4-, and 3,5-DNT). DNT has been found in soil, surface water, and groundwater near ammunition production plants. The major isomers of DNT are classified as "likely to cause cancer in humans."In vitro studies have provided conflicting data regarding the genotoxicity of the minor isomers. Studies indicate that metabolism in the gut and liver are necessary to convert DNT to genotoxic compounds. As such, in the present study the genotoxicity of isomers of DNT was assessed using two in vivo genotoxicity assays. The Comet assay was used to detect DNA damage in liver cells from male Sprague-Dawley rats following oral exposure (14-day) to individual isomers of DNT. The micronucleus assay was conducted using flow cytometric analysis to detect chromosomal damage in peripheral blood. Treatment with 2,3-, 3,4-, 2,4-, 2,5- and 3,5-DNT did not induce DNA damage in liver cells or increase the frequency of micronucleated reticulocytes (MN-RET) in peripheral blood at the doses tested. Treatment with 2,6-DNT induced DNA damage in liver tissue at all doses tested, but did not increase the frequency of micronucleated reticulocytes (MN-RET) in peripheral blood. Thus, 2,4-DNT and the minor isomers were not genotoxic under these test conditions, while 2,6-DNT was genotoxic in the target tissue, the liver. These results support previous research which indicated that the hepatocarcinogenicity of technical grade DNT (TG-DNT) could be attributed to the 2,6-DNT isomer.

Genotoxicity assessment of an energetic propellant compound, 3-nitro-1,2,4-triazol-5-one (NTO).

3-Nitro-1,2,4-triazol-5-one (NTO) is an energetic explosive proposed for use in weapon systems, to reduce the sensitivity of warheads. In order to develop toxicity data for safety assessment, we investigated the genotoxicity of NTO, using a battery of genotoxicity tests, which included the Ames test, Chinese Hamster Ovary (CHO) cell chromosome aberration test, L5178Y TK(+/-) mouse lymphoma mutagenesis test and rat micronucleus test. NTO was not mutagenic in the Ames test or in Escherichia coli (WP2uvrA). NTO did not induce chromosomal aberrations in CHO cells, with or without metabolic activation. In the L5178Y TK(+/-) mouse lymphoma mutagenesis test, all of the NTO-treated cultures had mutant frequencies that were similar to the average frequencies of solvent control-treated cultures, indicating a negative result. Confirmatory tests for the three in vitro tests also produced negative results. The potential in vivo clastogenicity and aneugenicity of NTO was evaluated using the rat peripheral blood micronucleus test. NTO was administered by oral gavage to male and female Sprague-Dawley rats for 14 days at doses up to 2g/kg/day. Flow cytometric analysis of peripheral blood demonstrated no significant induction of micronucleated reticulocytes relative to the vehicle control (PEG-200). These studies reveal that NTO was not genotoxic in either in vitro or in vivo tests and suggest a low risk of genetic hazards associated with exposure.

The effect of mirodenafil on the penile erection and corpus cavernosum in the rat model of cavernosal nerve injury.

Impotence is one of the common complications after the radical prostatectomy. One of the main reasons of this complication is due to the dysfunction of the veins in corpus cavernosum. Recent studies have shown that the erectile function is improved after the long-term therapy of phosphodiesterase type 5 inhibitor among patients with post-prostatectomy erectile dysfunction. In this study, we evaluated the effects of mirodenafil on the penile erection and corpus cavernosum tissues in the rat model of cavernosal nerve injury. Rats were divided into four groups: (1) control group, (2) bilateral cavernosal nerve injury group, (3) mirodenafil 10 mg therapy group after the nerve injury and (4) mirodenafil 20 mg therapy group after the nerve injury. After we identified the nerve from the pelvic nerve complex on the lateral side of the prostate, the rats in the control group were sutured without causing any nerve injury and in other groups we damaged the nerve by compressing it with a vessel clamp. Then, 10 and 20 mg kg(-1) of mirodenafil were orally administered to two experimental groups. After 8 weeks, the intracavernosal pressure (ICP) was recorded. The immunohistochemical staining and western blot were performed, and the effect of mirodenafil on the expression of cyclic guanosine monophosphate (cGMP) was evaluated through enzyme-linked immunosorbent assay. The ICP of nerve-injured group was decreased compared with the control group; however, the ICP of the mirodenafil-administered groups was improved compared with the nerve-injured group. The Masson's trichrome staining confirmed that the smooth muscle (SM) component was increased in the mirodenafil-administered groups. The nitric oxide synthase expression and cGMP of mirodenafil-administered groups was increased compared with the nerve-injured group. Long-term therapy of mirodenafil may improve the erectile function after the radical prostatectomy by preserving the SM content and inhibiting the fibrosis of the corpus cavernosum.