Molecular Initiating Events Associated with Drug-Induced Liver Malignant Tumors: An Integrated Study of the FDA Adverse Event Reporting System and Toxicity Predictions.

Liver malignant tumors (LMTs) represent a serious adverse drug event associated with drug-induced liver injury. Increases in endocrine-disrupting chemicals (EDCs) have attracted attention in recent years, due to their liver function-inhibiting abilities. Exposure to EDCs can induce nonalcoholic fatty liver disease and nonalcoholic steatohepatitis, which are major etiologies of LMTs, through interaction with nuclear receptors (NR) and stress response pathways (SRs). Therefore, exposure to potential EDC drugs could be associated with drug-induced LMTs. However, the drug classes associated with LMTs and the molecular initiating events (MIEs) that are specific to these drugs are not well understood. In this study, using the Food and Drug Administration Adverse Event Reporting System, we detected LMT-inducing drug signals based on adjusted odds ratios. Furthermore, based on the hypothesis that drug-induced LMTs are triggered by NR and SR modulation of potential EDCs, we used the quantitative structure-activity relationship platform for toxicity prediction to identify potential MIEs that are specific to LMT-inducing drug classes. Events related to cell proliferation and apoptosis, DNA damage, and lipid accumulation were identified as potential MIEs, and their relevance to LMTs was supported by the literature. The findings of this study may contribute to drug development and research, as well as regulatory decision making.

Synthetic cannabinoids enhanced ethanol-induced motor impairments through reduction of central glutamate neurotransmission.

Marijuana or synthetic cannabinoids and alcohol are often used together, with these combinations causing motor impairments that can subsequently lead to motor vehicle accidents. This study investigated the combined use of both synthetic cannabinoids and ethanol and their effect on motor coordination in mice in addition to examining the neurochemical changes in the cerebellum. Ethanol (2 g/kg, i.p.) significantly induced motor impairment in the accelerating rotarod test in mice. Furthermore, ethanol-induced motor impairments were further accentuated when combined with the synthetic cannabinoid, JWH-018 or AB-CHMINACA. The enhancement effects of the synthetic cannabinoids were completely antagonized by pretreatment with the selective CB1 receptor antagonist AM251, but not by the selective CB2 receptor antagonist AM630. Neurochemical study results showed that ethanol caused a reduction in the extracellular glutamate levels in the cerebellum during periods of ethanol-induced motor impairment. In addition to the enhanced motor impairment seen when ethanol was combined with JWH-018, these combinations also enhanced the reduction of the extracellular glutamate levels in the cerebellum. We additionally used microelectrode array recordings to examine the effects of ethanol and/or JWH-018 on the spontaneous network activity in primary cultures from mouse cerebellum. Results showed that ethanol combined with JWH-018 significantly reduced spontaneous neuronal network activity in the primary cerebellar culture. Our findings demonstrate that ethanol-induced motor impairments are enhanced by synthetic cannabinoids, with these effects potentially mediated by CB1 receptors. An accentuated reduction of neurotransmissions in the cerebellum may play an important role in motor impairments caused by ethanol combined with synthetic cannabinoids.

Investigation on the Effect of Capillary Microsampling on Hematologic and Toxicokinetic Evaluation in Regulatory Safety Studies in Mice.

Microsampling techniques enable the minimization of blood collection volume from animals and subsequent handling of the blood samples or their derived plasma or serum samples. This offers advantages over conventional large-volume sampling, such as eliminating the need for satellite animals and improving animal welfare aspects, and providing the opportunity for additional assessments in small animals where blood volume constraints limit endpoints. This study evaluated the feasibility of implementation of capillary microsampling (CMS) in a single-dose study in mice with the ultimate goal of enabling its use in toxicology studies. The focus was on the impact of microsampling on toxicokinetic assessment and on the subsequent hematology assessment in the same animal. A seventy (70)-µL blood collection via CMS from the tail vein had a minimal effect on the hematology parameters of mice (strain C57BL/6) in samples taken within 24 h of blood collection. TK parameters were similar in plasma samples collected via CMS and cardiac puncture sampling. A bioanalytical assay was developed which enabled the quantification of concentration of both the parent drug and a metabolite using only 5-µL plasma sample per analysis. Incurred sample reanalysis (ISR), unexpected event investigation, and re-assay were successfully performed on the limited samples (≤ 20 µL) collected from CMS. The results of this study confirmed the feasibility of implementing CMS in regulated mouse toxicity studies and demonstrated that it is possible to eliminate or reduce satellite animals.

Characteristics and circumstances of synthetic cannabinoid-related death.

Introduction: Synthetic cannabinoids are an emerging clinical and public health concern. The current study aimed to determine: (1) The characteristics and circumstances of death of all recorded cases of synthetic cannabinoid-related sudden or unnatural death in Australia, (2) The toxicology of cases and (3) Their major organ pathology.Methods: Retrospective study of all cases in Australia in which synthetic cannabinoid use was a mechanism contributory to death (n = 55) retrieved from the National Coronial Information System (2000-2017). Information was collected on cause of death, demographics, drug use history, circumstances of death, toxicology and major organ pathology.Results: The mean age was 37.2 years and 91.1% were male. Causes of death comprised of accidental toxicity (38.2%), accidental toxicity/cardiovascular disease (9.1%), natural disease (20.0%), suicide (10.9%) and traumatic accident (10.9%). The most common clinical presentation proximal to death was sudden collapse (25.5%). Cardiovascular disease was prominent: severe atherosclerosis (20.0%), myocardial replacement fibrosis (18.0%), cardiomegaly (12.0%). The most frequent synthetic cannabinoids were the indazolecarboxemides (61.8%), most commonly AB-CHMINACA (38.2%). The most frequent other substances were alcohol (34.5%) and Δ9-THC (23.6%).Conclusions: AB-CHMINACA was the most commonly seen synthetic cannabinoid. There was a high representation of relatively older decedents and of older males in particular. While acute toxicity was the most common cause of death, cardiovascular disease was prominent.

Cytotoxicity and mitochondrial dysfunction caused by the dietary supplement l-norvaline.

In addition to the 20 protein amino acids that are encoded for protein synthesis, hundreds of other naturally occurring amino acids, known as non-proteinogenic amino acids (NPAAs) exist. It is well known that some NPAAs are toxic through their ability to mimic protein amino acids, either in protein synthesis or in other metabolic pathways, and this property is utilised by some plants to inhibit the growth of other plants or kill herbivores. L-norvaline is an NPAA readily available for purchase as a dietary supplement. In light of previous evidence of l-norvaline's antifungal, antimicrobial and herbicidal activity, we examined the toxicity of l-norvaline to mammalian cells in vitro and showed that l-norvaline decreased cell viability at concentrations as low as 125 µM, caused necrotic cell death and significant changes to mitochondrial morphology and function. Furthermore, toxicity was reduced in the presence of structurally similar 'protein' amino acids, suggesting l-norvaline's cytotoxicity could be attributed to protein amino acid mimicry.

Convulsant Effects of Abused Synthetic Cannabinoids JWH-018 and 5F-AB-PINACA Are Mediated by Agonist Actions at CB1 Receptors in Mice.

Convulsant effects of abused synthetic cannabinoid (SCB) drugs have been reported in humans and laboratory animals, but the mechanism of these effects is not known. We compared convulsant effects of partial CB1R agonist ∆9-tetrahydrocannabinol (THC), full CB1R agonist SCBs JWH-018 and 5F-AB-PINACA, and classic chemical convulsant pentylenetetrazol (PTZ) using an observational rating scale in mice. THC did not elicit convulsions, but both SCBs did so as effectively as and more potently than PTZ. SCB-elicited convulsions were attenuated by the CB1R antagonist rimonabant or by THC, or by dose regimens of THC and JWH-018, which downregulate and desensitize CB1Rs. None of these treatments altered the convulsant effects of PTZ, although diazepam attenuated PTZ-elicited convulsions without altering SCB-induced convulsant effects. Repeated administration of a subthreshold dose of PTZ kindled convulsant effects, but this was not observed with the SCBs, and no cross-kindling was observed. Repeated administration of the SCBs resulted in tolerance to convulsant effects, but no cross-tolerance to PTZ was observed. Inhibition on Phase I metabolism via nonselective inhibition of CYP450s with 1-aminobenzotriazole potentiated the hypothermic effects of the SCBs and protected against the convulsant effects of JWH-018, but not those of 5F-AB-PINACA or PTZ. Incubation of human liver microsomes with the SCBs showed that JWH-018 is eliminated via oxidation, whereas 5F-AB-PINACA is not. These studies suggest that SCB-elicited convulsions are mediated by high intrinsic efficacy at CB1Rs and that benzodiazepines may not be effective treatments. Finally, drug metabolism may dramatically modulate the convulsant effects of some, but not all, SCBs.

Chemoembolization with Vascular Disrupting Agent CKD-516 Dissolved in Ethiodized Oil in Combination with Doxorubicin: A VX2 Tumor Model Study.

PURPOSE: To assess feasibility and efficacy of CKD-516, a vascular disrupting agent, in transarterial chemoembolization in a liver tumor model. MATERIALS AND METHODS: A VX2 carcinoma strain was implanted in rabbit liver (n = 40) and incubated for 2 weeks. After confirmation of tumor growth using computed tomography, transarterial chemoembolization was performed. CKD-516 was dissolved in ethiodized oil, and animals were allocated to 4 treatment groups (n = 10 in each): group A, ethiodized oil; group B, ethiodized oil/CKD-516; group C, ethiodized oil + doxorubicin; group D, ethiodized oil/CKD-516 + doxorubicin. To assess hepatic damage, serum aspartate transaminase and alanine transaminase levels were measured on day 1, 3, and 7 after delivery. To assess tumor necrosis, animals were euthanized on day 7, and explanted tumors were stained with hematoxylin and eosin and a terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling assay. Percentage areas of viable tumors were calculated using digitalized histopathologic specimen images. RESULTS: Tumor viability rates were 47.1% ± 11.4%, 27.5% ± 13.6%, 14.4% ± 12.5%, and 0.7% ± 1.0% in groups A, B, C, and D (P < .001). Liver enzyme levels were elevated after drug delivery but recovered during follow-up. Significant between-group differences were observed on days 1, 3, and 7 (aspartate transaminase and alanine transaminase: P = .0135 and P = .0134, P = .0390 and P = .0084, and P = .8260 and P = .0440). CONCLUSIONS: Treatment with a combination of CKD-516 and conventional transarterial chemoembolization showed therapeutic benefit in a liver tumor model.

Derivation of endogenous equivalent values to support risk assessment and risk management decisions for an endogenous carcinogen: Ethylene oxide.

An approach is presented for ethylene oxide (EO) to derive endogenous equivalent (EE) values, which are endogenous levels normally found within the body expressed in terms of exogenous exposures. EE values can be used to support risk assessment and risk management decisions for chemicals such as EO that have both endogenous and exogenous exposure pathways. EE values were derived using a meta-analysis of data from the published literature characterizing the distribution for an EO biomarker of exposure, hemoglobin N-(2-hydroxyethyl)-valine (HEV), in unexposed populations. These levels are compared to the those reported in exposed populations (smokers, workers). Correlation between the biomarker of exposure and external exposures of EO were applied to this distribution to determine corresponding EE values, which range from 0.13 to 6.9 ppb for EO in air. These values are orders of magnitude higher than risk-based concentration values derived for EO using default methods, and are provided as a pragmatic, data-driven alternative approach to managing the potential risks from exogenous exposures to EO.

VX-509 (Decernotinib)-Mediated CYP3A Time-Dependent Inhibition: An Aldehyde Oxidase Metabolite as a Perpetrator of Drug-Drug Interactions.

(R)-2-((2-(1H-pyrrolo[2,3-b]pyridin-3-yl)pyrimidin-4-yl)amino)-2-methyl-N-(2,2,2-trifluoroethyl)butanamide (VX-509, decernotinib) is an oral Janus kinase 3 inhibitor that has been studied in patients with rheumatoid arthritis. Patients with rheumatoid arthritis often receive multiple medications, such as statins and steroids, to manage the signs and symptoms of comorbidities, which increases the chances of drug-drug interactions (DDIs). Mechanism-based inhibition is a subset of time-dependent inhibition (TDI) and occurs when a molecule forms a reactive metabolite which irreversibly binds and inactivates drug-metabolizing enzymes, potentially increasing the systemic load to toxic concentrations. Traditionally, perpetrating compounds are screened using human liver microsomes (HLMs); however, this system may be inadequate when the precipitant is activated by a non-cytochrome P450 (P450)-mediated pathway. Even though studies assessing competitive inhibition and TDI using HLM suggested a low risk for CYP3A4-mediated DDI in the clinic, VX-509 increased the area under the curve of midazolam, atorvastatin, and methyl-prednisolone by approximately 12.0-, 2.7-, and 4.3-fold, respectively. Metabolite identification studies using human liver cytosol indicated that VX-509 is converted to an oxidative metabolite, which is the perpetrator of the DDIs observed in the clinic. As opposed to HLM, hepatocytes contain the full complement of drug-metabolizing enzymes and transporters and can be used to assess TDI arising from non-P450-mediated metabolic pathways. In the current study, we highlight the role of aldehyde oxidase in the formation of the hydroxyl-metabolite of VX-509, which is involved in clinically significant TDI-based DDIs and represents an additional example in which a system-dependent prediction of TDI would be evident.

An outbreak of acute delirium from exposure to the synthetic cannabinoid AB-CHMINACA.

BACKGROUND: Synthetic cannabinoid containing products are a public health threat as reflected by a number of outbreaks of serious adverse health effects over the past 4 years. The designer drug epidemic is characterized by the rapid turnover of synthetic cannabinoid compounds on the market which creates a challenge in identifying the particular etiology of an outbreak, confirming exposure in cases, and providing current information to law enforcement. RESULTS: Between 28 May 2014 and 8 June 2014, 35 patients were evaluated and treated at the University of Florida Health Medical Center in Gainesville following reported exposure to a synthetic cannabinoid containing product obtained from a common source. Patients demonstrated acute delirium (24) and seizures (14), and five required ventilator support and ICU-level care; none died. The presence of N-[(1S)-1-(aminocarbonyl)-2-methylpropyl]-1-(cyclohexylmethyl)-1H-indazole-3-carboxamide (AB-CHMINACA), or one of its predicted metabolites was confirmed in 15 of 21 cases. A rapid public health response and aggressive public messaging prevented further morbidity, identified the source, and led to law enforcement seizure of the implicated product. DISCUSSION: The significance of this outbreak lies as much in the rapid occurrence of unpredictable, life-threatening adverse health effects from a newly identified synthetic cannabinoid compound as it does in the multidisciplinary investigation and novel partnership between local public health, the laboratory, and the chemical industry, resulting in termination of the outbreak. CONCLUSION: A coordinated response and collaboration between law enforcement, the local public health, emergency medical services and Health Center staff, were all key interventions in preventing a more substantial public health outbreak resulting from use of a novel synthetic cannabinoid compound. Real time collaborations between toxicology laboratories, suppliers of analytical standards and the public health system may be useful in the face of future novel chemical exposures.

The Efficacy and Safety of the Novel Peripheral Analgesic Isovaline as an Adjuvant to Propofol for General Anesthesia and Conscious Sedation: A Proof-of-Principle Study in Mice.

BACKGROUND: The combination of propofol and an opioid analgesic is widely used for procedural sedation, as well as total IV anesthesia. However, opioids produce respiratory depression, a primary cause of death due to these agents. We recently reported on the antinociceptive actions of isovaline, a small nonbiogenic amino acid that does not readily cross the blood-brain barrier and acts on peripheral γ-aminobutyric acid type B receptors. Here, we explored the possibility that isovaline may be an effective and safe alternative to opioids as an adjunct to propofol for producing anesthesia. METHODS: With approval from our Animal Care Committee, we conducted an in vivo study in adult female CD-1 mice using Dixon's "up-and-down" method for dose assessment. Animals received intraperitoneal saline, propofol, isovaline, fentanyl, or coadministration of propofol with isovaline or fentanyl. We assessed hypnosis by a loss of righting reflex and immobility by an absence of motor response to tail clip application. General anesthesia was defined as the presence of both hypnosis and immobility. We assessed conscious sedation as a decrease in time on a rotarod. The maximal dose without respiratory rates of <4 per minute, apnea, or death was defined as the maximal tolerated dose. RESULTS: Either isovaline or fentanyl coadministered with propofol at its half-maximal effective dose (ED50) for hypnosis produced general anesthesia (isovaline ED50, 96 mg/kg [95% confidence interval {CI}, 88-124 mg/kg]; fentanyl ED50, 0.12 mg/kg [95% CI, 0.08-3.5 mg/kg]). Propofol produced hypnosis (ED50, 124 mg/kg [95% CI, 84-3520 mg/kg]) but did not block responses to tail clip application. Neither isovaline nor fentanyl produced hypnosis at doses which produced immobility (isovaline ED50, 350 mg/kg [95% CI, 286-1120 mg/kg]; fentanyl ED50, 0.35 mg/kg [95% CI, 0.23-0.51 mg/kg]). Isovaline at its analgesic ED50, coadministered with a subhypnotic dose of propofol (40 mg/kg), did not exacerbate propofol-induced deficits in rotarod performance. The median maximal tolerated dose of fentanyl coadministered with the hypnotic ED50 of propofol was 11 mg/kg (95% CI, 8-18 mg/kg). Isovaline at a maximal deliverable (soluble) dose of 5000 mg/kg produced no apparent respiratory depression or other adverse effects. CONCLUSIONS: The novel analgesic, isovaline, coadministered with propofol, produced general anesthesia and conscious sedation in mice. The margin of safety for propofol-isovaline was considerably higher than that for propofol-fentanyl. This study's results show that propofol-based sedation and general anesthesia can be effectively and safely produced by replacing the conventional opioid component with a brain-impermeant peripherally acting γ-aminobutyric acid type B receptor agonist. The results provide proof of the principle of combining a peripheral analgesic with a centrally acting hypnotic to produce general anesthesia. This principle suggests a novel approach to clinical general anesthesia and conscious sedation.

Nonproteinogenic D-amino acids at millimolar concentrations are a toxin for anaerobic microorganisms relevant to early Earth and other anoxic planets.

The delivery of extraterrestrial organics to early Earth provided a potentially important source of carbon and energy for microbial life. Optically active organic compounds of extraterrestrial origin exist in racemic form, yet life on Earth has almost exclusively selected for L- over D-enantiomers of amino acids. Although D-enantiomers of proteinogenic amino acids are known to inhibit aerobic microorganisms, the role of concentrated nonproteinogenic meteoritic D-amino acids on anaerobic metabolisms relevant to early Earth and other anoxic planets such as Mars is unknown. Here, we test the inhibitory effect of D-enantiomers of two nonproteinogenic amino acids common to carbonaceous chondrites, norvaline and α-aminobutyric acid, on microbial iron reduction. Three pure strains (Geobacter bemidjiensis, Geobacter metallireducens, Geopsychrobacter electrodiphilus) and an iron-reducing enrichment culture were grown in the presence of 10 mM D-enantiomers of both amino acids. Further tests were conducted to assess the inhibitory effect of these D-amino acids at 1 and 0.1 mM. The presence of 10 mM D-norvaline and D-α-aminobutyric acid inhibited microbial iron reduction by all pure strains and the enrichment. G. bemidjiensis was not inhibited by either amino acid at 0.1 mM, but D-α-aminobutyric acid still inhibited at 1 mM. Calculations using published meteorite accumulation rates to the martian surface indicate D-α-aminobutyric acid may have reached inhibitory concentrations in little over 1000 years during peak infall. These data show that, on a young anoxic planet, the use of one enantiomer over another may render the nonbiological enantiomer an environmental toxin. Processes that generate racemic amino acids in the environment, such as meteoritic infall or impact synthesis, would have been toxic processes and could have been a selection pressure for the evolution of early racemases.

Intermittent oral coadministration of a gamma secretase inhibitor with dexamethasone mitigates intestinal goblet cell hyperplasia in rats.

Dexamethasone was given in 2 oral dosing regimens with repeat dose oral administration of the gamma secretase inhibitor (GSI), PF-03084014, in Sprague-Dawley (SD) rats in order to evaluate the effects of coadministration of dexamethasone on GSI-induced goblet cell hyperplasia (GCH) in the intestinal tract. Safety end points were evaluated in 1 week and 1 month studies. The dosing regimens tested in the 1-month studies included a 1-week pretreatment with 1.0 mg/kg dexamethasone followed by a 3-week repeat dose treatment with 100 mg/kg GSI or concurrent intermittent treatment with 1.0 mg/kg dexamethasone on weeks 1 and 3 and repeat dose treatment with 100 mg/kg GSI for 4 weeks. Pretreatment with dexamethasone for 1 week transiently mitigated the severity of intestinal GCH for up to 1 week. Intermittent coadministration of dexamethasone on weeks 1 and 3 with GSI repeat dosing for 4 weeks mitigated intestinal GCH for up to 4 weeks post treatment. Treatment-related morbidity and mortality occurred on day 7 with 150 mg/kg GSI and 5 mg/kg dexamethasone coadministration, and on days 13, 14, and 23 with 100 mg/kg GSI and 1 mg/kg dexamethasone coadministration.

Preclinical analysis of the γ-secretase inhibitor PF-03084014 in combination with glucocorticoids in T-cell acute lymphoblastic leukemia.

T-cell acute lymphoblastic leukemias (T-ALL) and lymphomas are aggressive hematologic cancers frequently associated with activating mutations in NOTCH1. Early studies identified NOTCH1 as an attractive therapeutic target for the treatment of T-ALL through the use of γ-secretase inhibitors (GSI). Here, we characterized the interaction between PF-03084014, a clinically relevant GSI, and dexamethasone in preclinical models of glucocorticoid-resistant T-ALL. Combination treatment of the GSI PF-03084014 with glucocorticoids induced a synergistic antileukemic effect in human T-ALL cell lines and primary human T-ALL patient samples. Mechanistically PF-03084014 plus glucocorticoid treatment induced increased transcriptional upregulation of the glucocorticoid receptor and glucocorticoid target genes. Treatment with PF-03084014 and glucocorticoids in combination was highly efficacious in vivo, with enhanced reduction of tumor burden in a xenograft model of T-ALL. Finally, glucocorticoid treatment effectively reversed PF-03084014-induced gastrointestinal toxicity via inhibition of goblet cell metaplasia. These results warrant the analysis of PF-03084014 and glucocorticoids in combination for the treatment of glucocorticoid-resistant T-ALL.

Concomitant angiotensin AT1 receptor antagonism and neprilysin inhibition produces omapatrilat-like antihypertensive effects without promoting tracheal plasma extravasation in the rat.

Dual inhibition of angiotensin-converting enzyme (ACE) and neprilysin (NEP) by drugs such as omapatrilat produces superior antihypertensive efficacy but cause high incidence of angioedema. We examined whether dual inhibition of angiotensin AT1 receptor (ARB) and NEP (ARB-NEPI, valsartan-candoxatril) provides similar efficacy to omapatrilat without the risk of angioedema. Activity of test compounds at the targets was assayed using fluorescence-based enzyme assays (ACE, NEP, aminopeptidase P) or competition binding assays (AT1). Target engagement in vivo (ACE, AT1, and NEP) was quantified by measuring inhibition of angiotensin-pressor responses and potentiation of atrial natriuretic peptide-induced urinary cyclic guanosine monophosphate (cGMP) output in rats. Tracheal plasma extravasation (TPE) was used as a surrogate to assess propensity of compounds to promote upper airway angioedema. Antihypertensive efficacy in renin-dependent and -independent states was measured in spontaneously hypertensive rats and deoxycorticosterone acetate salt hypertensive rats, respectively. Administration of omapatrilat and coadministration of valsartan and candoxatril blocked angiotensin induced vasopressor responses and potentiated atrial natriuretic peptide-induced increase in urinary cGMP output. In spontaneously hypertensive rats, valsartan, omapatrilat, and valsartan-candoxatril combination all produced reduction in blood pressure to a similar extent, whereas candoxatril was ineffective. In deoxycorticosterone acetate rats, omapatrilat, candoxatril, and valsartan-candoxatril combination but not valsartan produced reduction in blood pressure. Antihypertensive doses of omapatrilat produced robust increases in TPE; by contrast, valsartan, candoxatril, or their combination did not increase TPE. Pretreatment with icatibant, a bradykinin B2 antagonist, abolished omapatrilat-induced TPE but not its antihypertensive effects. On the background of NEP inhibition, suppression of the renin-angiotensin system through ARB and ACE inhibition shows a similar antihypertensive efficacy but exerts differential effects on bradykinin metabolism and TPE indicative of reduced risk of angioedema. Thus, dual AT1 receptor blockade and NEP inhibition is potentially an attractive approach to retain the excellent antihypertensive effects of omapatrilat but with a superior safety profile.

Angiotensin II receptor blocker induced fetopathy: 7 cases.

BACKGROUND: During a period of 12 months 7 newborns with a partially severe fetopathy caused most probably by maternal sartan-intake in pregnancy were treated in 5 German teaching hospitals. Sartans antagonize the effect of angiotensin II at the AT1-receptor and are used to treat arterial hypertension. METHOD: We presented 2 cases at the yearly GNPI meeting 2010 and we were informed about similar cases in other German teaching hospitals which we brought together in this publication. RESULTS: In the presented cases, maternal sartan intake was noticed at different times in pregnancy and was in part discontinued some weeks before delivery. In all pregnancies oligohydramnios was present and fetal kidneys displayed a hyperechogenic structure on ultrasound. The newborns' postnatal course varied: oligohydramnios sequence with lung hypoplasia, arterial hypotension and renal insufficiency were the predominant problems of the first days of life. The majority (4/7) of infants did not survive this period, in other cases there was a complete (1/7) recovery of renal function whereas others survived with renal impairment (2/7), in part requiring chronic dialysis. Further distinctive features seen frequently were disturbances of cranial ossification and flaccid paralysis of hands and feet with deviations as well as sensorineural hearing loss. CONCLUSION: These case reports again underline the hazardousness of maternal sartan intake with potential fatal outcome for the newborn. Though the use of sartans in pregnancy is contraindicated and several case reports of sartan induced fetopathies exist, the risk of sartan treatment generally seems to be underestimated.

Synthesis, characterization, cytotoxic activities, and DNA-binding studies of ternary copper(II) complexes with new coumarin derivatives.

In this study, two novel complexes [Cu(MCVH)phen(H(2)O)].ClO(4) (1) and [Cu(MCLH)phen(H(2)O)].ClO(4) (2) (here, MCVH(2)=(7-hydroxy-4-methyl-8-coumarinyl) valine, MCLH(2)=(7-hydroxy-4-methyl-8-coumarinyl) leucine) have been synthesized and characterized by elemental analyses, molar conductance, infrared spectra (IR), (1)H-NMR and UV-Vis measurements. The interactions of them with calf thymus DNA (ct DNA) have been investigated by absorption spectroscopy, fluorescence spectroscopy, circular dichroism spectroscopy and viscosity measurements. Experimental results reveal an intercalative interaction with DNA for the complexes, furthermore the binding affinity of 2 is higher than that of 1 according to the calculated binding constant values. In addition, they were evaluated for their cytotoxic activities toward human prostate cancer cell (PC3), human liver cell (L02) and human myeloid leukemia cancer cell (HL-60) by acid phosphoatase assay. Both of them showed significant cytotoxic potency.

MNT and MutaMouse studies to define the in vivo dose response relations of the genotoxicity of EMS and ENU.

Although there are a multitude of in vitro and in vivo studies on the genotoxic activity of EMS, no lifetime carcinogenicity studies, repeat dose mutation data or exposure analysis are available to serve as a solid basis for risk assessment for human exposure cases. The present studies were undertaken to investigate whether a threshold for mutagenic and clastogenic activity in vivo could be established, using the bone marrow micronucleus (MNT) and MutaMouse test systems, in the hope to provide reassurance to the patients that their accidental exposure to EMS at doses up to 0.055 mg/kg did not carry a toxicological risk. Dose levels ranging from 1.25 to 260 mg/kg/day were applied orally for up to 28 days. As a reference we included ENU at doses of 1.1-22 mg/kg/day. Our studies showed that daily doses of up to 25mg/kg/day (bone marrow, GI tract) and 50 mg/kg/day (liver) did not induce mutations in the lacZ gene in the three organs tested. Doses up to 80mg/kg/day (7-day dosing regime) did not induce micronuclei in mouse bone marrow. The genotoxic activity of EMS became apparent only at higher dose levels. Dose fractionation of EMS (28 times 12.5mg/kg versus a single high dose 350 mg/kg) provided further evidence for the thresholded dose response of EMS and showed that no cumulation of gene mutations below a threshold was occurring. In contrast, for ENU no threshold was apparent and dose fractionation indicated full additivity of individual dose effects.

Chronic treatment with angiotensin AT1 receptor antagonists reduced serum but not bone TGF-beta1 levels in ovariectomized rats.

Approximately 50% of hypertensive patients are postmenopausal women; therefore, any antihypertensive therapy must not adversely affect bone loss in this population. Recently, however, concern has been raised that use of angiotensin AT1 receptor antagonists may increase the tendency to develop postmenopausal osteoporosis by decreasing transforming growth factor-beta1 (TGF-beta1), which has been implicated in bone mass maintenance. In the present study, we selected telmisartan and valsartan as representatives of angiotensin AT1 receptor antagonists and used ovariectomized (OVX) rats as a model of human postmenopausal osteoporosis. After 3 months treatment with telmisartan (5 mg/kg daily) or valsartan (10 mg/kg daily), OVX rats showed no signs of adverse effects on bone mineral density of the lumbar vertebrae (L1-L5) or the total femur, nor did treatment affect serum levels of osteocalcin and osteoclast-derived tartrate-resistant acid phosphatase (TRACP-5b). Bone TGF-beta1 content remained unchanged, although treatment with telmisartan and valsartan significantly reduced serum TGF-beta1 levels (p < 0.05). In conclusion, chronic treatment with angiotensin AT1 receptor antagonists reduced serum but not bone TGF-beta1 levels and did not accelerate ovariectomy-induced bone loss in rats.