Toxicological assessment of electronic cigarette vaping: an emerging threat to force health, readiness and resilience in the U.S. Army

The U.S. Army and U. S. Army Public Health Center are dedicated to protecting the health, and readiness of Department of the Army Service Members, civilians, and contractors. Despite implementation of health programs, policies and tobacco control interventions, the advent of electronic nicotine delivery systems (ENDS), including electronic cigarettes (e-cigs), represent unregulated and poorly defined systems to supplant or substitute use of conventional nicotine products (e.g., cigarettes and pipe tobacco). E-cigs present unique challenges to healthcare officials vested in preventive medicine. The health impact of an e-cig and vaping on an individual's acute or chronic disease susceptibility, performance and wellness, is fraught with uncertainty. Given the relatively recent emergence of e-cigs, high-quality epidemiological studies, and applied biological research studies are severely lacking. In sparsely available epidemiological studies of short-term cardiovascular and respiratory health outcomes, any attempt at addressing the etiology of acute and chronic health conditions from e-cig use faces incredible challenges. Until relatively recently, this was complicated by an absent national regulatory framework and health agency guidance on the manufacture, distribution, selling and use of e-cigs or similar ENDS devices and their chemical constituents. Two key issues underpin public health concern from e-cig use: 1) continued or emergent nicotine addiction and potential use of these devices for vaping controlled substances; and 2) inadvertent sudden-onset or chronic health effects from inhalational exposure to low levels of complex chemical toxicants from e-cig use and vaping the liquid. Herein, the health impacts from e-cig vaping and research supporting such effects are discussed.

COVID-19 - Changes in Workload and Clinical Practice in Trauma and Orthopaedics in a District General Hospital in the United Kingdom

Introduction:

COVID-19 has had a significant impact on the entire health system. The trauma and orthopaedic service has been compelled to alter working practices to respond proactively and definitively to the crisis. The aim of this study is to summarise the impact of this outbreak on the trauma and orthopaedic workload and outline the response of the department.

Materials and Methods:

We retrospectively collected data comparing patient numbers pre-COVID-19, and prospectively during the early COVID-19 pandemic. We have collected the numbers and nature of outpatient orthopaedic attendances to fracture clinics and elective services, inpatient admissions and the number of fracture neck of femur operations performed.

Results:

The number of outpatient attendances for a musculoskeletal complaint to Accident and Emergency and the number of virtual fracture clinic reviews reduced by almost 50% during COVID-19. The number of face-to-face fracture clinic follow-ups decreased by around 67%, with a five-fold increase in telephone consultations. Inpatient admissions decreased by 33%, but the average number of fracture neck of femur operations performed has increased by 20% during COVID-19 compared to pre-COVID-19 levels.

Conclusion:

We have noted a decrease in some aspects of the trauma and orthopaedic outpatient workload, such as leisure and occupational-related injuries but an increase in others, such as fracture neck of femurs. Many injuries have significantly reduced in numbers and we consider that a model could be developed for treating these injuries away from the acute hospital site entirely, thereby allowing the acute team to focus more appropriate major trauma injuries.

Toxicity and occupational exposure assessment for Fischer-Tropsch synthetic paraffinic kerosene

Fischer-Tropsch (FT) Synthetic Paraffinic Kerosene (SPK) jet fuel is a synthetic organic mixture intended to augment petroleum-derived JP-8 jet fuel use by the U.S. armed forces. The FT SPK testing program goal was to develop a comparative toxicity database with petroleum-derived jet fuels that may be used to calculate an occupational exposure limit (OEL). Toxicity investigations included the dermal irritation test (FT vs. JP-8 vs. 50:50 blend), 2 in vitro genotoxicity tests, acute inhalation study, short-term (2-week) inhalation range finder study with measurement of bone marrow micronuclei, 90-day inhalation toxicity, and sensory irritation assay. Dermal irritation was slight to moderate. All genotoxicity studies were negative. An acute inhalation study with F344 rats exposed at 2000 mg/m³ for 4 hr resulted in no abnormal clinical observations. Based on a 2-week range-finder, F344 rats were exposed for 6 hr per day, 5 days per week, for 90 days to an aerosol-vapor mixture of FT SPK jet fuel (0, 200, 700 or 2000 mg/m³). Effects on the nasal cavities were minimal (700 mg/m³) to mild (2000 mg/m³); only high exposure produced multifocal inflammatory cell infiltration in rat lungs (both genders). The RD₅₀ (50% respiratory rate depression) value for the sensory irritation assay, calculated to be 10,939 mg/m^3, indicated the FT SPK fuel is less irritating than JP-8. Based upon the proposed use as a 50:50 blend with JP-8, a FT SPK jet fuel OEL is recommended at 200 mg/m³ vapor and 5 mg/m³ aerosol, in concurrence with the current JP-8 OEL.

Efficacy, pharmacokinetic and pharmacodynamic evaluation of apaziquone in the treatment of non-muscle invasive bladder cancer

INTRODUCTION

Apaziquone (also known as EO9 and Qapzola^TM) is a prodrug that is activated to DNA damaging species by oxidoreductases (particularly NQO1) and has the ability to kill aerobic and/or hypoxic cancer cells. Areas covered: Whilst its poor pharmacokinetic properties contributed to its failure in phase II clinical trials when administered intravenously, these properties were ideal for loco-regional therapies. Apaziquone demonstrated good anti-cancer activity against non-muscle invasive bladder cancer (NMIBC) when administered intravesically to marker lesions and was well tolerated with no systemic side effects. However, phase III clinical trials did not reach statistical significance for the primary endpoint of 2-year recurrence in apaziquone over placebo although improvements were observed. Post-hoc analysis of the combined study data did indicate a significant benefit for patients treated with apaziquone, especially when the instillation of apaziquone was given 30 min or more after surgery. A further phase III study is ongoing to test the hypotheses generated in the unsuccessful phase III studies conducted to date. Expert opinion: Because of its specific pharmacological properties, Apaziquone is excellently suited for local therapy such as NMIBC. Future studies should include proper biomarkers.

Abstract P5-11-07: Pharmacokinetics of eflapegrastim in a phase 2 open-label dose-ranging study in breast cancer patients receiving TC regimen

Background: Eflapegrastim (SPI-2012/HM10460A) is a novel, long acting recombinant human granulocyte colony-stimulating factor (rhG-CSF). Eflapegrastim consists of an rhG-CSF conjugated to the recombinant E coli derived Fc fragment of IgG4 via a polyethylene glycol linker. Eflapegrastim is in clinical development for the treatment of chemotherapy induced neutropenia in cancer patients.

Methods: Pharmacokinetics (PK) of eflapegrastim was investigated in an open label, dose-ranging Phase 2 study in breast cancer patients receiving docetaxel + cyclophosphamide (TC) chemotherapy. The study consisted of 4 arms. Patients in Arms 1 through 3 received subcutaneous doses of 45, 135, or 270 µg /kg of eflapegrastim and patients in Arm 4 received 6 mg pegfilgrastim (Neulasta®) on Day 2 of each 21-day chemotherapy cycle. Serum samples were collected from a subset of eflapegrastim patients at pre-specified time-points and analyzed for eflapegrastim by a validated enzyme-linked immunosorption assay (ELISA). Pharmacokinetic analyses were conducted on serum concentration-time profiles after dosing in Cycle 1. The serum concentrations for samples collected in Cycle 3 were compared with the corresponding concentrations in Cycle 1. Pharmacokinetic analyses were not conducted for pegfilgrastim patients.

Results: The PK profile of eflapegrastim was investigated in 11 patients, including 3 patients in the 45 µg/kg treatment arm, 4 patients in the 135 µg/kg treatment arm, and 4 patients in the 270 µg/kg treatment arm. Following single eflapegrastim doses of 45, 135, or 270 µg/kg, peak serum concentrations increased in a dose proportional manner. The summary of pharmacokinetics of eflapegrastim is presented in the Table below.

Pharmacokinetic Parameters of Eflapegrastim in Patients Following Single Subcutaneous Doses in Cycle 1ParameterEflapegrastim 45 μg/kg/Eflapegrastim 135μg/kgEflapegrastim 270 μg/kgCmax, ng/mLN = 3; Mean = 7.00; SD = 6.08N = 4; Mean = 247; SD = 276N =3; Mean = 299; SD = 329Tmax, haN =2; Mean = 58.7; SD = 46.9 - 70.5N = 4; Mean =9.00; SD = 8 - 48.1N = 3; Mean = 24.00; SD = 24 - 24.1AUC0-312, ng•hr/mLN = 0; Mean = NC; SD = NCN = 2; Mean = 16000; SD = 5850N = 3; Mean = 22900; SD = 25100t1/2, hbN = 0; Mean = NC; SD = NCN = 2; Mean = 81.0; SD = 88.4N = 1; Mean = 31.5; SD = NCAUC = area under the concentration-time curve; Cmax = maximum serum concentration; h = hour; NC = not calculated; SD = standard deviation; t1/2 = half-life; Tmax = time to maximum serum concentration; a) Expressed as median and range; b) Expressed as harmonic mean and pseudo SD

The maximum serum concentrations of eflapegrastim in Cycle 3 increased with the dose of eflapegrastim. The serum concentrations of eflapegrastim in Cycle 3 were generally lower than those in Cycle 1, but the profile was similar to Cycle 1.

Conclusions: The Cmax and AUC(0-312) of eflapegrastim increased in a dose proportional manner following subcutaneous administration. The half-life of eflapegrastim ranged from 31.5 to 81.0 hours, which is consistent with the half-life of other long-acting myeloid growth factors.

Citation Format: Vacirca JL, Papai Z, Horvath Z, Makharadze R, Reddy G, Song T, Koli P, Schwartzberg LS. Pharmacokinetics of eflapegrastim in a phase 2 open-label dose-ranging study in breast cancer patients receiving TC regimen [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-11-07.

Abstract P5-11-08: Immunogenicity of eflapegrastim in a phase 2 open-label dose-ranging study of eflapegrastim in breast cancer patients receiving TC regimen

Background: Eflapegrastim (SPI-2012/HM10460A) is a novel, long-acting recombinant human granulocyte colony-stimulating factor (rhG-CSF). Eflapegrastim consists of an rhG-CSF conjugated to a recombinant E. coli derived Fc fragment of IgG4 via a polyethylene glycol linker. Eflapegrastim is in clinical development for the treatment of chemotherapy induced neutropenia in cancer patients.

Methods: Immunogenicity of eflapegrastim was investigated in an open label, dose-ranging Phase 2 study in breast cancer patients receiving docetaxel + cyclophosphamide (TC) chemotherapy. The study consisted of 4 arms. Patients in Arms 1 through 3 received subcutaneous doses of 45, 135, or 270 µg/kg eflapegrastim and Arm 4 received 6 mg pegfilgrastim (Neulasta®) on Day 2 of each 21-day chemotherapy cycle. Blood samples for immunogenicity analysis were collected before the start of each chemotherapy cycle (Day 1) and at the End-of-Study Visit. Samples were tested in a screening assay for Anti-Drug Antibodies (ADA) to eflapegrastim by a validated enzyme linked immunosorption assay (ELISA). Positive samples from the screening assay were further tested in a confirmatory assay for antibodies binding to eflapegrastim or G-CSF. Samples found positive in the confirmatory assay were further tested in a validated cell based neutralizing antibody assay.

Results: Serum samples from 143 patients in the study were tested for ADA to eflapegrastim and G-CSF. Preexisting antibodies binding to eflapegrastim or G-CSF were detected in 9 out of 143 (6.3%) patients. One out of the 27 patients (3.7%) in the Pegfilgrastim Arm who was negative prior to dosing was positive for ADA in the G-CSF confirmatory assay. Two out of 100 patients (2.0%) treated with eflapegrastim, who were negative prior to dosing, demonstrated treatment-induced formation of ADA in the G-CSF confirmatory assay. However, the responses in these patients were transient (ie, not consistently positive at all the sampling times) and the assay response values were low and only slightly above the plate-specific cut points. None of the patients tested were positive for G-CSF neutralizing antibodies. A formal assessment of the impact of serum ADA on the PK of eflapegrastim was not performed since PK was examined in only a limited number of patients and all of those patients were negative for ADA both at study initiation and post-dose.

Conclusion: No neutralizing antibodies against eflapegrastim or G-CSF were detected in patients administered eflapegrastim in this study.

Citation Format: Vacirca JL, Papai Z, Agajanian R, Horvath Z, Makharadze R, Ibrahim E, Koli P, Reddy G, Tedesco KL, McGregor K, Schwartzberg LS. Immunogenicity of eflapegrastim in a phase 2 open-label dose-ranging study of eflapegrastim in breast cancer patients receiving TC regimen [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-11-08.

Toxicity Assessment of Thiodiglycol

Sulfur mustard (HD) undergoes hydrolysis to form various products such as thiodiglycol (TG) in biological and environmental systems. TG is a precursor in the production of HD and it is also considered as a “Schedule 2” compound (dual-use chemicals with low to moderate commercial use and high-risk precursors). Several toxicological studies on TG were conducted to assess environmental and health effects. The oral LD50 values were >5000 mg/kg in rats. It was a mild skin and moderate ocular irritant and was not a skin sensitizer in animals. It was not mutagenic in Ames Salmonella, Escherichia coli, mouse lymphoma, and in vivo mouse micronucleus assays, but it induced chromosomal aberrations in Chinese hamster ovarian (CHO) cells. A 90-day oral subchronic toxicity study with neat TG at doses of 0, 50, 500, and 5000 mg/kg/day (5 days/week) in Sprague-Dawley rats results show that there are no treatment-related changes in food consumption, hematology, and clinical chemistry in rats of either sex. The body weights of both sexes were significantly lower than controls at 5000 mg/kg/day. Significant changes were also noted in both sexes in absolute weights of kidneys, kidney to body weight ratios, and kidney to brain weight ratios, in the high-dose group. The no-observed-adverse-effect level (NOAEL) for oral toxicity was 500 mg/kg/day. The developmental toxicity conducted at 0, 430, 1290, and 3870 mg/kg by oral gavage showed maternal toxicity in dams receiving 3870 mg/kg. TG was not a developmental toxicant. The NOAEL for the developmental toxicity in rats was 1290 mg/kg. The provisional oral reference dose (RfD) of 0.4 mg/kg/day was calculated for health risk assessments. The fate of TG in the environment and soil showed biological formation of thiodiglycalic acid with formation of an intermediate ((2-hydroxyethyl)thio)acetic acid. It was slowly biodegraded under anaerobic conditions. It was not toxic to bluegill sunfish at 1000 mg/L and its metabolism and environmental and biochemical effects are summarized.

Genotoxicity Assessment of Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)

Hexahydro-1,3,5-trinitro-1,3,5-triazine, a polynitramine compound, commonly known as RDX, has been used as an explosive in military munitions formulations since World War II. There is considerable data available regarding the toxicity and carcinogenicity of RDX. It has been classified as a possible carcinogen (U.S. Environmental Protection Agency, Integrated Risk Information System, 2005, www.epa.gov/IRIS/subst/0313.htm ). In order to better understand its gentoxic potential, the authors conducted the in vitro mouse lymphoma forward mutation and the in vivo mouse bone marrow micronucleus assays. Pure RDX (99.99%) at concentrations ranging from 3.93 to 500 μg/ml showed no cytotoxicity and no mutagenicity in forward mutations at the thymidine kinase (TK) locus in L5178Y mouse lymphoma cells, with and without metabolic activation. This finding was also confirmed by repeat assays under identical conditions. In addition, RDX did not induce micronuclei in mouse bone marrow cells when tested to the maximum tolerated dose of 250 mg/kg in male mice. These results show that RDX was not mutagenic in these in vitro and in vivo mammalian systems.

Reevaluation of a Twenty-Four-Month Chronic Toxicity/Carcinogenicity Study of Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in the B6C3F1 Hybrid Mouse

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) has been widely used as an explosive in U.S. army munitions formulations since World War II. Two-year carcinogenicity studies revealed RDX to be noncarcinogenic in two strains of rats, but a 2-year carcinogenicity study in B6C3F1 mice revealed an increased incidence of hepatocellular neoplasms in females. Based on results of the study in B6C3F1 mice, RDX has been classified as a possible carcinogen. The authors reevaluated the archived histological sections from the B6C3F1 mouse study, using current histopathologic diagnostic criteria and interpretations. The earlier evaluation showed a statistically significant increase in the incidence of hepatocellular adenoma/carcinoma in female mice from the three highest dose groups (7, 35, and 175/100 mg/kg/day). The revaluation yielded a slightly lower incidence at each of the dose levels in female mice. The reduced number of hepatocellular neoplasms was largely due to reclassification of hepatocellular adenomas as foci of cytoplasmic alteration, in compliance with current diagnostic criteria. The reevaluation was reviewed by a pathology working group (PWG), which arrived at a consensus classification of each lesion. Based on the consensus diagnoses of the PWG, only one female group (35 mg/kg/day) showed a significant increase when compared to controls. The incidence of hepatocellular neoplasms for all groups, including the 35 mg/kg/day group, was within the reported incidence range for spontaneous hepatocellular neoplasms in female B6C3F1 mice. The increased incidence of hepatocellular neoplasms in female mice given RDX at 35 mg/kg/day was interpreted as equivocal evidence of a carcinogenic effect.

Subchronic Toxicity of 1,3,5-Trinitrobenzene in Fischer 344 Rats

The subchronic toxicity of 1,3,5-trinitrobenzene (TNB) in male and female Fischer 344 rats was evaluated by feeding a powdered certified laboratory diet containing 0, 66.7, 400 and 800 mg TNBl kg diet for 90 days. The calculated average TNB intake was 4.29, 24.70, and 49.28 mg/kg body weight (BW)day for females and 3.91, 22.73, and 44.16 mg/ kg BWI day for males. Food intake in the 400 and 800 mg/kg diet dose groups of both sexes was decreased throughout the study and resulted in a significant decrease in absolute body weights. A significant decrease in relative testicular weights and a significant increase in the relative liver weight were observed in male rats receiving 400 or 800 mg TNB/kg diet. A significant increase in the relative spleen weights of both sexes receiving 400 or 800 mg TNB diet was noted. The relative liver weight was also increased only in female rats maintained on the 800 mg TNB diet. Histopathological examinations revealed that the susceptible organs for TNB toxicity were kidney (hyaline droplets) in all male dose groups and testes (seminiferous tubular degeneration) in rats receiving 400 and 800 mg TNB diet groups. The spleen was also affected (extramedullary hematopoiesis) in both sexes in the 400 and 800 mg dose groups. Hematological studies at both 45 (data not given) and 90 days in the 400 and 800 mg dose groups indicated decreased values for red blood cell counts and hemoglobin content, while reticulocytes and methemoglobin levels were increased. Clinical chemistry parameters were unaffected. Based on kidney toxicity and hematological effects, a Low Observed Adverse Effect Level (LOAEL) of 3.91 mg/kg BWI day was suggested for subchronic toxicity studies on TNB.

Toxicity of 2,4,6-TrinitrotoIuene (TNT) in Hispid Cotton Rats (Sigmodon hispidus): Hematological, Biochemical, and Pathological Effects

The contamination of soil and water with munitions chemicals and their degradation products has been reported at certain munitions production waste disposal sites and at certain Army installations. The effects of 2,4,6-trinitrotoluene (TNT) on wild cotton rats ( Sigmodon hispidus) were evaluated to identify target organ toxicity that could be used to develop biomarkers for exposure assessment for ecological and health risks. The oral LD50 values for TNT in corn oil were 607 and 767 mg/kg body weights for male and female cotton rats respectively. Hematological, pathological, and biochemical effects of TNT were determined after daily oral gavage of TNT in corn oil at doses of 0, 75.9, 151.8, and 303.5 (males) or 0, 96, 192, and 384 mg/kg (females) for 7 days. Cotton rats treated with TNT showed an increase in spleen weights in males (303.5 mg/kg) and in females (192 and 384 mg/kg). Cotton rats of both sexes treated for 7 days with TNT had marked hemolytic anemia with reduced erythrocytes, hemoglobin, and hematocrit in high-dose groups; methemoglobin levels were elevated significantly in males at mid and high dose. Hepatic drug metabolizing enzyme analysis revealed that microsomal O-dealkylation of methoxy, ethoxy, and pentoxy resorufin were elevated in male (high dose) cotton rats. The activity of hepatic glutathione S-transferases (GST) was significantly elevated in male (mid and high dose) and female (all doses) cotton rats exposed to TNT. Histopathological analysis of spleen revealed mild to marked splenic congestion with mild extramedullary hematopoiesis, hemosiderosis, and lymphoid hyperplasia in male and female cotton rats treated with TNT (all doses). Liver weights were increased in males (mid and high dose) and in females (high-dose group). In the high-dose groups, histological changes in liver (mild to moderate hepatocellular hypertrophy, increased hemosiderin pigment in Kupffer cells) in both sexes, and in testis (premature exfoliation of spermatozoa from dilated seminiferous tubules) were observed (mid and high dose). These results suggest that hepatic GST and hemolytic anemia may be biomarkers in cotton rats of terrestrial contamination with TNT or other nitroaromatic explosive compounds.

Gas Chromatographic and Mass Spectrometric Determination of Hemoglobin Adducts of 1,3-Dinitrobenzene and 1,3,5-Trinitrobenzene in Shrew Cryptotis Parva

1,3-Dinitrobenzene (DNB) and 1,3,5-trinitrobenzene (TNB) are used primarily in explosive compositions and munitions and have been detected as environmental contaminants of surface waters as well as ground waters near production waste disposal sites. Hemoglobin (Hb) adducts have recently been proposed as biological markers of exposure assessment for various environmental compounds, including nitroaromatics. In the present study, we have investigated the formation of DNB and TNB hemoglobin adducts in vivo and in vitro in the blood of shrew (Cryptotis parva). DNB and TNB hemoglobin adducts were detected by gas chromatography/mass spectrometry (GC/MS) after either basic (0.1 N NaOH) or acid (2 N HCl) hydrolysis followed by organic solvent extraction and derivatization of the corresponding amines. The levels of DNB-Hb adducts detected after basic hydrolysis (238.7 & pm; 50.2 pg/mg Hb) are higher than the corresponding levels detected after acid hydrolysis (52.5 & pm; 16.2 pg/mg Hb). For the TNB-Hb the levels after acid hydrolysis (132.2 & pm; 37.8 pg/mg Hb) are higher than the levels detected after basic hydrolysis (44.7 & pm; 15.3 pg-mg Hb). These results demonstrate the effectiveness of the hemoglobin adduct model for monitoring exposure to nitroaromatics.

Toxicity of Tetryl (N-Methyl-N,2,4,6–Tetranitroaniline) in F344 Rats

The toxicity of tetryl (N-methyl-N,2,4,6–tetranitroaniline) in male and female F344 rats was evaluated after adminstration in the diet for 14 or 90 days. The 14–day study diet concentrations used were 0, 500, 1250, 2000, 2500, and 5000 ppm; the 90–day study diet concentrations were 0, 200, 1000, and 3000 ppm tetryl in the diet. The calculated average daily tetryl intake was 32.1, 82.5, 130.3, 178.9, and 374.4 mg/kg body weight (BW) for females and 31.8, 80.0, 121.0, 170.5, and 349.7 mg/kg BW for males in the 14–day study. For the 90–day studies, the daily tetryl intake was 14.2, 68.8, and 199.0 mg/kg BW for females and 13.0, 62.4, and 179.6 mg/kg BW for males. In the 14–day study, there was a significant decrease in body weights (males), whereas relative(organ/body weight) liver and spleen (females), and kidney (males) weights were significantly increased in the 5000–ppm dose group. Hematological effects observed were decreased hemoglobin and hematocrit and an increased number of reticulocyts in females (2000 to 5000 ppm). Methemoglobin levels in males (2000 to 5000 ppm) and females (5000 ppm) and total blood protein and albumin levels in all groups of males and females (except 500 ppm) were significantly increased. Histopathological changes were observed in kidneys (deposition of cytoplasmic droplets) of all dose groups of male rats. In the sub–chronic (90–day) study, feed intake was reduced in all dose groups, but a significant decrease in terminal body weights was observed in females (1000 and 3000 ppm) and males (3000 ppm). An increase in the relative liver, kidney (1000–3000 ppm), and spleen (3000 ppm) weights were noted in both sexes. The hemoglobin content and red blood cell count were decreased whereas the reticulocyte count was elevated (3000 ppm) in both sexes at 45 and 90 days. Methemoglobin levels were increased in both sexes (1000 and 3000 ppm). Histopathologicalchanges were noted in the spleen (pigment deposition and erythroid cell hyperplasia) of both sexes (3000 ppm) and kidneys (tubular degeneration and cytoplasmic droplets containing alpha-2-micro globulin) of male rats (1000 to 3000 ppm). A no observed adverse effect level (NOAEL) for both sexes was 13 mg/kg BW/day was determined.

In Vitro Inhibition of Mammalian Glutathione Transferases by Selected Nitrobenzenes

Five structurally related nitrobenzenes (1,2-dinitrobenzene, 1,3-dinitrobenzene, 1,4-dinitrobenzene, 1,3,5-trinitrobenzene, and picric acid) and Meisenheimer complex [1-(S-glutathionyl)-2,4,6-trinitrocyclohexadienate] were evaluated as possible inhibitors of affinity purified mammalian glutathione transferases (GSTs) isolated from human liver or human term placenta and rat fiver. The results suggest that the degree of GST inhibition depends upon both the chemical in question and the enzyme source. Among the nitrobenzenes tested, 1,3,5-trinitrobenzene (TNB) was found to be the most potent inhibitor of GST activity toward 1-chloro-2,4-dinitrobenzene (CDNB) from all the sources, whereas 1,3-dinitrobenzene (1,3-DNB) was the least effective. TNB-caused inhibition of GST activity toward CDNB appeared to be isozyme specific in that compared to the enzyme from human term placenta (GSTP1–1), the degree of inhibition of the mixture of GST isozymes present in the fivers of adult rats and humans was low. The enzyme assays conducted with 3,4-dichloro-1-nitrobenzene (DCNB), ethacrynic acid (EA), and 4-nitropyridinei N-oxide also suggested the isozymespecific inhibition of rat fiver GST activity by TNB. The nature of TNB-caused inhibition of GSTP1–1 was competitive with respect to CDNB and yielded a Ki value of 12.5 θ M. With EA, a specific substrate for GSTP1–1, an IC50 value of ∼ 16 θ M was estimated for the GSTP1–1 inhibition by TNB. The Meisenheimer complex, the product of nonenzymatic GSH conjugation with TNB by different GSTs, was found to be the most potent inhibitor of mammalian GSTs, and IC50 values ranged between 1 and 4 θ M when the enzyme activity was assayedusing CDNB. The nature of GSTP1–1 inhibition was noncompetitive with respect to CDNB, with a Ki value of 1 θ M for Meisenheimer complex. Although a precise mechanism was not identified, it is postulated that GSH depletion and/or GST inhibition may contribute, at least partly, to the target organ toxicity caused by exposures of animals to different nitrobenzenes reported in the literature.

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.

Oral toxicity evaluation of thiodiglycol in Sprague-Dawley rats

Thiodiglycol (TDG) is the main product of sulfur mustard hydrolysis and is an environmental contaminant. Subacute and subchronic oral toxicity studies with TDG were conducted in Sprague-Dawley rats. Neat TDG was administered by gavage at doses of 157, 313, 625, 1250, 2500, 5000, and 9999 mg/kg/d, 5 days per week, for 14 days. In the 14-day study, decreased body weight and food consumption were observed at 5000 mg/kg/d. In the 90-day study, rats received neat TDG at doses of 50, 500, or 5000 mg/kg/d for 5 days per week. A fourth group served as a sham control. Individual body weight and food consumption were measured weekly. At termination of the experiment, urine, blood, and tissue samples were collected. Rats displayed significant decreased body weight with no effect on food consumption following administration of TDG at 5000 mg/kg/d. Both male and female rats showed significant increased kidney weights at 5000 mg/kg/d. The organ to body weight ratios increased significantly for liver, kidneys, testes, and brain in males and adrenals in females for 5000 mg/kg/d. At all doses of TDG, hematological and clinical parameters and tissue histopathology remained unaltered. The no observed adverse effect level (NOAEL) for oral subchronic toxicity was 500 mg/kg/d. Benchmark dose (BMD) was derived from the decreased gain in body weight that was seen in male rats. A BMD based on a 10% decrease in body weight was 1704 mg/kg/d, and the lower confidence limit on the dose BMD, the BMDL, was 372 mg/kg/d.

175 EFFECT OF ACETYL-CoA CARBOXYLASE (ACC) INHIBITOR ON THE LIPID CONTENT AND NUCLEAR MATURATION OF CANINE OOCYTES

Compared with other domestic species, embryo technologies are least developed for the dog. This is mainly due to difficulties in producing mature oocytes in vitro. Canine oocytes contain exceptionally high amounts of lipid. High lipid content increases the chilling sensitivity of oocytes and embryos. Mechanical and chemical reductions of the lipid content have been used to improve the cryotolerance of oocytes. Additionally, chemical stimulation of lipid catabolism improved oocyte in vitro maturation (IVM) rates in other species (You et al. 2012 Theriogenology 78, 235–543). Acetyl-CoA carboxylase (ACC) is the rate-limiting enzyme in de novo lipogenesis and its expression has been reported in oocytes and embryos. In somatic cells, inhibition of ACC reduces lipogenesis and enhances β-oxidation. Our hypothesis is that treatment of oocytes with an inhibitor of ACC (CP640186, Pfizer Animal Health, New York, NY, USA) reduces lipid content and improves IVM rate of oocytes. Ovaries were collected from a spay clinic and sliced in HEPES-buffered TCM-199 to recover oocytes. In vitro maturation was conducted at 38.5°C, 5% CO2, and high humidity in TCM-199 supplemented with 1% fetal bovine serum, glutamine, sodium pyruvate, β-mercaptoethanol, oestradiol, epidermal growth factor, and antimicrobial agents (Songsasen et al. Mol. Reprod. Dev. 79, 186–196). During the first 19 to 21 h, the IVM media contained 4 concentrations of the inhibitor (0+DMSO, 0.02, 0.1, and 0.5 μM, designated as treatments 1, 2, 3, and 4, respectively) and then oocytes were transferred to a medium without the inhibitor and cultured for an additional 27 to 29 h. At the end of culture (total of 48 h), oocytes were denuded of cumulus layers, washed, fixed, and stained with Nile red (lipid) and Hoechst-33342 (chromatin), and then mounted on a microscope slide. Lipid content and chromatin status were evaluated using fluorescent microscopy (TRITC and DAPI filters, respectively). The relative lipid content was measured by the corrected total cell fluorescence (CTCF) using ImageJ software (http://rsbweb.nih.gov/ij/). Data on CTCF and proportions of chromatin status of oocytes were analysed using one-way ANOVA (SigmaPlot 11.0). The mean CTCF for each treatment was 5.5 × 109 (n = 51, 5.2 × 109 (n = 44), 4.5 × 109 (n = 31), and 4.8 × 109 (n = 34), respectively (P = 0.3; 4 replicates). At the highest dose, the agent induced relatively more cumulus cell layer expansion but inhibited their attachment to the dish; the latter effect was reversible because cumulus cells attached and proliferated after washing the oocytes of the agent. Metaphase II was rare (≤3.1%); however, the proportion of oocytes developing to ≥GVBD stage (Trt 1 14%, n = 37; Trt 2 41%, n = 56; Trt 3 5%, n = 22; Trt 4 11%, n = 43) was affected by treatments. Our preliminary data indicate that a low concentration of ACC inhibitor has a positive effect on the nuclear maturation of canine oocytes but the effect on lipid content as estimated by using Nile red fluorescence intensity appears to be minimal.

Surgical treatment of pediatric epileptic encephalopathies

Pediatric epileptiform encephalopathies are a group of neurologically devastating disorders related to uncontrolled ictal and interictal epileptic activity, with a poor prognosis. Despite the number of pharmacological options for treatment of epilepsy, many of these patients are drug resistant. For these patients with uncontrolled epilepsy, motor and/or neuropsychological deterioration is common. To prevent these secondary consequences, surgery is often considered as either a curative or a palliative option. Magnetic resonance imaging to look for epileptic lesions that may be surgically treated is an essential part of the workup for these patients. Many surgical procedures for the treatment of epileptiform encephalopathies have been reported in the literature. In this paper the evidence for these procedures for the treatment of pediatric epileptiform encephalopathies is reviewed.

Toxicity Assessment of 4-Amino-2-Nitrotoluene

4-Amino-2-nitrotoluene (4A2NT; CAS 119-32-4) is a degradation product of 2,4-dinitrotoluene. The toxicity data on 4A2NT are limited. Therefore, we collected toxicity data from rats to assess environmental and human health effects from exposures. The approximate lethal dose for both sexes was 5000 mg/kg. A 14-day toxicity study in rats was conducted with 4A2NT in the feed at concentrations of 0, 125, 250, 500, 1000, and 2000 ppm. Based on a 14-day oral dose range toxicity study with 4A2NT in the feed, 2000 ppm was selected as highest concentration for a subsequent 90-day study. An oral 90-day subchronic toxicity study in rats was conducted with concentrations of 0, 500, 1000, or 2000 ppm of 4A2NT in the feed. The calculated consumed doses of 4A2NT in the feed were 0, 27, 52, or 115 mg/kg/d for males and 0, 32, 65, or 138 mg/kg/d for females. A no-observed adverse effect level could not be determined. The lowest observed adverse effect level was 27 mg/kg/d for males and 32 mg/kg/d for female rats based upon decreased body weight gain. The decreased body weight gain in male rats was the most sensitive adverse event observed in this study and was used to derive a benchmark dose (BMD). A BMD of 23.1 mg/kg/d and BMD with 10% effect level of 15.5 mg/kg/d were calculated for male rats, which were used to derive an oral reference dose (RfD). The human RfD of 1.26 μg/kg/d was derived using current United States Environmental Protection Agency guidelines.

Genotoxicity assessment of ethylenediamine dinitrate (EDDN) and diethylenetriamine trinitrate (DETN)

Ethylenediamine dinitrate (EDDN) and diethylenetriamine trinitrate (DETN) are relatively insensitive explosive compounds that are being explored as safe alternatives to other more sensitive compounds. When used in combination with other high explosives they are an improvement and may provide additional safety during storage and use. The genetic toxicity of these compounds was evaluated to predict the potential adverse human health effects from exposure by using a standard genetic toxicity test battery which included: a gene mutation test in bacteria (Ames), an in vitro Chinese Hamster Ovary (CHO) cell chromosome aberration test and an in vivo mouse micronucleus test. The results of the Ames test showed that EDDN increased the mean number of revertants per plate with strain TA100, without activation, at 5000μg/plate compared to the solvent control, which indicated a positive result. No positive results were observed with the other tester strains with or without activation in Salmonella typhimurium strains TA98, TA1535, TA1537, and Escherichia coli strain WP2 uvrA. DETN was negative for all Salmonella tester strains and E. coli up to 5000μg/plate both with and without metabolic activation. The CHO cell chromosome aberration assay was performed using EDDN and DETN at concentrations up to 5000μg/mL. The results indicate that these compounds did not induce structural chromosomal aberrations at all tested concentrations in CHO cells, with or without metabolic activation. EDDN and DETN, when tested in vivo in the CD-1 mouse at doses up to 2000mg/kg, did not induce any significant increase in the number of micronuclei in bone marrow erythrocytes. These studies demonstrate that EDDN is mutagenic in one strain of Salmonella (TA100) but was negative in other strains, for in vitro induction of chromosomal aberrations in CHO cells, and for micronuclei in the in vivo mouse micronucleus assay. DETN was not genotoxic in all in vitro and in vivo tests. These results show the in vitro and in vivo genotoxicity potential of these chemicals.

Abstract P6-14-08: Lucanthone Inhibits Autophagy and Promotes Cathepsin D-Mediated Apoptosis in Breast Cancer Cells

Autophagy is an evolutionarily conserved degradation pathway that eliminates certain proteins, defective organelles, and protein aggregates in order to maintain protein homeostasis and prevent abnormal cells from replicating. However, the autophagy machinery may also be utilized to generate ATP from organelles and other cellular components to promote survival under metabolic/hypoxic stress conditions. Since nutrient and oxygen deprivation are hallmark characteristics of the tumor microenvironment, disrupting autophagic degradation may be a promising approach to selectively kill cancer cells. Chloroquine and its derivatives are the only clinically relevant autophagic inhibitors that are currently being evaluated for their potential applications in cancer therapy. However, these drugs are known to cause ocular toxicity, especially irreversible retinopathy, and this underscores the need for additional inhibitors of autophagy with more favorable therapeutic indices. Lucanthone is an anti-schistome agent that is being investigated for cancer therapy as a sensitizer to chemotherapy and radiation. Here we report a novel mechanism of action for lucanthone that is characterized by the disruption of lysosomal function, inhibition of autophagy, and induction of apoptosis. Exposure to lucanthone resulted in the processing and recruitment of microtubule-associated protein 1 light chain 3 (LC3) to autophagosomes, but induced lysosomal membrane permeabilization and impaired autophagic degradation as revealed by electron microscopy and the accumulation of p62/SQSTM1. Importantly, lucanthone displayed more potent activity against a panel of breast cancer cell lines compared to chloroquine. Cathepsin D is a lysosomal protease that functions to promote apoptosis following its release into the cytosol upon lyososomal disruption. In order to elucidate the mechanism by which lucanthone induces apoptosis in cancer cells, we investigated the potential effects of lucanthone on cathepsin D expression and subcellular localization. As expected based on its effects on the integrity of lysosomes, lucanthone treatment stimulated a highly significant increase in cytosolic cathepsin D expression, which was associated with apoptosis induction. Accordingly, cathepsin D-targeted siRNA blocked the ability of lucanthone to stimulate its expression and significantly reduced lucanthone-mediated apoptosis. Subsequent experiments revealed that the anticancer activity of lucanthone occurred through a mechanism independent of the functional status of the p53 tumor suppressor. Considering that p53 is functionally inactivated in the majority of cancers, the ability of lucanthone to retain anticancer activity under p53 deficient conditions could have important clinical implications. Collectively, this study establishes a novel mechanism of action for lucanthone as an autophagy inhibitor and provides a rationale for its use in combination with anticancer agents that induce this important survival pathway.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-14-08.

Calcium Signaling in Neuronal Cells Exposed to the Munitions Compound Cyclotrimethylenetrinitramine (RDX)

Cyclotrimethylenetrinitramine (RDX) has been used extensively as an explosive in military munitions. Mechanisms for seizure production, seen in past animal studies, have not been described. Increased calcium levels contribute to excitotoxicity, so in this study neuroblastoma cells are loaded with calcium-indicating dye before application of 1.5 µM to 7.5 mM RDX, with fluorescence recorded for 30 cycles of 11 seconds each. The lowest concentration of RDX increases calcium fluorescence significantly above baseline for cycles 2 to 8; millimolar concentrations increase calcium fluorescence significantly above baseline for cycles 2 to 30. Increases in calcium, like those of 200 nM carbachol, are prevented with 10 mM of calcium chelator ethylene glycol-bis(β-aminoethyl ether)-N,N,N,N tetra-acetic acid (EGTA, tetrasodium salt). Calcium channel blocker verapamil (20 μM), Ca2+-ATPase inhibitor thapsigargin (5 μM), and general membrane stabilizer lidocaine (10 mM) partially attenuate carbachol- and RDX-induced increases in calcium, suggesting that RDX transiently increases intracellular calcium by multiple mechanisms.

Prediction of mortality in adult emergency department patients with sepsis

OBJECTIVES

To determine the efficacy of the abbreviated Mortality in Emergency Department Sepsis (MEDS) score, the Modified Early Warning (MEW) score and near-patient-test (NPT) lactate levels in predicting 28-day mortality in adult emergency department (ED) patients with sepsis.

METHODS

A retrospective cohort study of adult ED patients with sepsis admitted to hospital was conducted in a large urban teaching and a district general hospital. Data were collected during four time periods between 1 January 2006 and 31 January 2007. Inclusion criteria were age > or =16 years and an ED diagnosis of sepsis. Primary outcome for all patients was 28-day mortality. Patients were preassigned to risk groups according to their abbreviated MEDS score, MEW score and NPT lactate.

RESULTS

307 ED patients with sepsis were included in the study. Among these there were 72 deaths (23%). Mortality rates for the low-, moderate- and high-risk groups of the abbreviated MEDS score were 1/63 (1.6%), 48/205 (23.4%) and 23/39 (59.0%) patients. The MEDS score for low-risk patients was 98.6% (95% CI 92.5% to 99.9%) sensitive and 26.5% (95% CI 21.0% to 32.6%) specific and for high-risk patients it was 31.9% (95% CI 21.4% to 44.0%) sensitive and 93.2% (95% CI 89.2% to 96.1%) specific for death within 28 days. Mortality rates for the low- and high-risk MEW score were 20/159 (12.6%) and 52/148 (35.1%) patients. The MEW score for high-risk patients was 72.2% (95% CI 60.4% to 82.1%) sensitive and 59.2% (95% CI 52.6% to 65.5%) specific for mortality. An NPT lactate level of > or =4 mmol/l was 49.1% (95% CI 35.1% to 63.2%) sensitive and 74.3% (95% CI 64.8% to 82.3%) specific for 28-day mortality.

CONCLUSION

These results demonstrate the efficacy of the abbreviated MEDS score, the MEW score and NPT venous lactate levels in predicting 28-day mortality in ED patients with sepsis. The abbreviated MEDS score was found to be the best performing risk assessment model which, with prospective validation, may aid early clinical decision-making in ED patients with sepsis and might affect the outcome from sepsis.

Water-mediated interactions between hydrophobic and ionic species in cylindrical nanopores

We use Metropolis Monte Carlo and umbrella sampling to calculate the free energies of interaction of two methane molecules and their charged derivatives in cylindrical water-filled pores. Confinement strongly alters the interactions between the nonpolar solutes and completely eliminates the solvent separated minimum (SSM) that is seen in bulk water. The free energy profiles show that the methane molecules are either in contact or at separations corresponding to the diameter and the length of the cylindrical pore. Analytic calculations that estimate the entropy of the solutes, which are solvated at the pore surface, qualitatively explain the shape of the free energy profiles. Adding charges of opposite sign and magnitude 0.4e or e (where e is the electronic charge) to the methane molecules decreases their tendency for surface solvation and restores the SSM. We show that confinement induced ion-pair formation occurs whenever l(B)/D approximately O(1), where l(B) is the Bjerrum length and D is the pore diameter. The extent of stabilization of the SSM increases with ion charge density as long as l(B)/D<1. In pores with D<or=1.2 nm, in which the water is strongly layered, increasing the charge magnitude from 0.4e to e reduces the stability of the SSM. As a result, ion-pair formation that occurs with negligible probability in the bulk is promoted. In larger diameter pores that can accommodate a complete hydration layer around the solutes, the stability of the SSM is enhanced.