Risk assessment of N-nitrosodiethylamine (NDEA) and N-nitrosodiethanolamine (NDELA) in cosmetics

N-nitrosamines and their precursors found in cosmetics may be carcinogenic in humans. Thus the aim of this study was to carry out risk assessment for N-nitrosamines (N-nitrosodiethanolamine [NDELA], N-nitrosodiethylamine [NDEA]) and amines (triethanolamine [TEA], diethanolamine [DEA]) levels in cosmetics determined using validated liquid chromatography–tandem mass spectrometry (LC–MS/MS) procedures. NDELA and NDEA concentrations were present at levels of “not detected” (N.D.) to 596.5 μg/kg and N.D. to 40.9 μg/kg, respectively. TEA and DEA concentrations ranged from N.D. to 860 μg/kg and N.D. to 26.22 μg/kg, respectively. The nitrite concentration (3–2250 mg/l), number of nitrosating agents to a maximum 5, and pH (3.93–10.09) were also assessed. The impact of N-nitrosamine formation on the levels of TEA, DEA, nitrite, and other nitrosating agents was also examined. N-nitrosamine concentrations correlated with the number of nitrosating agents and nitrite concentrations. Data demonstrated that higher nitrite concentrations and a greater number of nitrosating agents increased NDELA and NDEA yields. Further, the presence of TEA and DEA exerted a significant influence on N-nitrosamine formation. Risk assessments, including the margin of exposure (MOE) and lifetime cancer risk (LCR) for N-nitrosamines and margin of safety (MOS) for amines, were calculated using product type, use pattern, and concentrations. Exposure to maximum amounts of NDELA and NDEA resulted in MOE > 10,000 (based upon the benchmark dose lower confidence limit 10%) and LCR <1 × 10^?5, respectively. In addition, TEA and DEA concentrations in cosmetic samples resulted in MOS values >100. Therefore, no apparent safety concerns were associated with cosmetic products containing NDELA, NDEA, TEA, and DEA in this study. However, since amines and nitrosating agents produce carcinogenic nitrosamines, their use in cosmetics needs to be minimized to levels as low as technically feasible.     

Potential Application of Benzo(a)Pyrene-Associated Adducts (Globin or Lipid) as Blood Biomarkers for Target Organ Exposure and Human Risk Assessment

In order to investigate the potential application of blood biomarkers as surrogate indicators of carcinogen–adduct formation in target-specific tissues, temporal formation of benzo[a]pyrene (BaP)-associated DNA adducts, protein adducts, or lipid damage in target tissues such as lung, liver, and kidney was compared with globin adduct formation or plasma lipid damage in blood after continuous intraperitoneal (ip) injection of [³H]BaP into female ICR mice for 7 d. Following treatment with [³H]BaP, formation of [³H]BaP–DNA or –protein adducts in lung, liver, and kidney increased linearly, and persisted thereafter. This finding was similar to the observed effects on globin adduct formation and plasma lipid damage in blood. The lungs contained a higher level of DNA adducts than liver or kidneys during the treatment period. Further, the rate of cumulative adduct formation in lung was markedly greater than that in liver. Treatment with a single dose of [³H]BaP indicated that BaP–globin adduct formation and BaP–lipid damage in blood reached a peak 48 h after treatment. Overall, globin adduct formation and lipid damage in blood were significantly correlated with DNA adduct formation in the target tissues. These data suggest that peripheral blood biomarkers, such as BaP–globin adduct formation or BaP–lipid damage, may be useful for prediction of target tissue-specific DNA adduct formation, and for risk assessment after exposure.     

Sex differences in sarcopenia and frailty among community-dwelling Korean older adults with diabetes: The Korean Frailty and Aging Cohort Study

Aims/IntroductionWe aimed to examine the prevalence of sarcopenia and frailty in Korean older adults with diabetes compared with individuals without diabetes.Materials and MethodsWe analyzed the data of 2,403 participants aged 70–84 years enrolled in the Korean Frailty and Aging Cohort Study. Sarcopenia was defined using the Asian Working Group for Sarcopenia and the Foundation for the National Institutes of Health. Frailty was assessed by the Cardiovascular Health Study frailty phenotype criteria.ResultsThe mean age of the participants was 76.0 ± 3.9 years, and 47.2% were men. The prevalence of diabetes was 30.2% in men and 25.8% in women. Adults with diabetes showed a lower muscle mass index (appendicular skeletal muscle mass/body mass index) and handgrip strength in both sexes, but only the women showed decreased physical performance. Women with diabetes presented a higher prevalence of sarcopenia diagnosed by the Foundation for the National Institutes of Health criteria, and frailty compared with participants without diabetes (sarcopenia 14.7% vs 8.5%, P = 0.001; frailty 9.5% vs 4.9%, P = 0.003). Men in the high and middle tertiles for homeostatic model assessment of insulin resistance presented a significantly higher prevalence of sarcopenia, compared with men in the low tertile homeostatic model assessment of insulin resistance (high tertile 16.6%, middle tertile 13.3%, low tertile 8.6%).ConclusionsIn older adults with diabetes, muscle mass index and muscle strength were lower than in those without diabetes. However, the prevalence of sarcopenia and frailty was higher and physical performance was lower only in women with diabetes.     

Repetitive Treatment with Diluted Bee Venom Attenuates the Induction of Below-Level Neuropathic Pain Behaviors in a Rat Spinal Cord Injury Model

The administration of diluted bee venom (DBV) into an acupuncture point has been utilized traditionally in Eastern medicine to treat chronic pain. We demonstrated previously that DBV has a potent anti-nociceptive efficacy in several rodent pain models. The present study was designed to examine the potential anti-nociceptive effect of repetitive DBV treatment in the development of below-level neuropathic pain in spinal cord injury (SCI) rats. DBV was applied into the Joksamli acupoint during the induction and maintenance phase following thoracic 13 (T13) spinal hemisection. We examined the effect of repetitive DBV stimulation on SCI-induced bilateral pain behaviors, glia expression and motor function recovery. Repetitive DBV stimulation during the induction period, but not the maintenance, suppressed pain behavior in the ipsilateral hind paw. Moreover, SCI-induced increase in spinal glia expression was also suppressed by repetitive DBV treatment in the ipsilateral dorsal spinal cord. Finally, DBV injection facilitated motor function recovery as indicated by the Basso–Beattie–Bresnahan rating score. These results indicate that the repetitive application of DBV during the induction phase not only decreased neuropathic pain behavior and glia expression, but also enhanced locomotor functional recovery after SCI. This study suggests that DBV acupuncture can be a potential clinical therapy for SCI management.     

Conical ultrashort echo time (UTE) MRI in the evaluation of pediatric acute appendicitis

Purpose

Magnetic resonance imaging (MRI) sequences with conical k-space trajectories are able to decrease motion artifacts while achieving ultrashort echo times (UTE). We assessed the performance of free-breathing conical UTE MRI in the evaluation of the pediatric pelvis for suspected appendicitis.

Methods

Our retrospective review of 84 pediatric patients who underwent MRI for suspected appendicitis compared three contrast-enhanced sequences: free-breathing conical UTE, breath-hold three-dimensional (3D) spoiled gradient echo (BH-SPGR), and free-breathing high-resolution 3D SPGR (FB-SPGR). Two radiologists performed blinded and independent evaluations of each sequence for image quality (four point scale), anatomic delineation (four point scale), and diagnostic confidence (five point scale). Subsequently, the three sequences were directly compared for overall image quality (− 3 to + 3 scale). Scores were compared using Kruskal–Wallis and Wilcoxon signed-rank tests.

Results

UTE demonstrated significantly better perceived signal-to-noise ratio (SNR) and fewer artifacts than BH-SPGR and FB-SPGR (means of 3.6 and 3.4, 3.4 and 3.2, 3.1 and 2.7, respectively; p < 0.0006). BH-SPGR and FB-SPGR demonstrated significantly better contrast than UTE (means of 3.6, 3.4, and 3.2, respectively; p < 0.03). In the remaining categories, UTE performed significantly better than FB-SPGR (p < 0.00001), while there was no statistical difference between UTE and BH-SPGR. Direct paired comparisons of overall image quality demonstrated the readers significantly preferred UTE over both BH-SPGR (mean + 0.5, p < 0.00001) and FB-SPGR (mean + 1.2, p < 0.00001).

Conclusions

In the evaluation of suspected appendicitis, free-breathing conical UTE MRI performed better in the assessed metrics than FB-SPGR. When compared to BH-SPGR, UTE demonstrated superior perceived SNR and fewer artifacts.

     

Oral administration of PEGylated TLR7 ligand ameliorates alcohol-associated liver disease via the induction of IL-22

Effective therapies for alcohol-associated liver disease (ALD) are limited; therefore, the discovery of new therapeutic agents is greatly warranted. Toll-like receptor 7 (TLR7) is a pattern recognition receptor for single-stranded RNA, and its activation prevents liver fibrosis. We examined liver and intestinal damage in Tlr7^−/− mice to determine the role of TLR7 in ALD pathogenesis. In an alcoholic hepatitis (AH) mouse model, hepatic steatosis, injury, and inflammation were induced by chronic binge ethanol feeding in mice, and Tlr7 deficiency exacerbated these effects. Because these results demonstrated that endogenous TLR7 signaling activation is protective in the AH mouse model, we hypothesized that TLR7 activation may be an effective therapeutic strategy for ALD. Therefore, we investigated the therapeutic effect of TLR7 agonistic agent, 1Z1, in the AH mouse model. Oral administration of 1Z1 was well tolerated and prevented intestinal barrier disruption and bacterial translocation, which thus suppressed ethanol-induced hepatic injury, steatosis, and inflammation. Furthermore, 1Z1 treatment up-regulated the expression of antimicrobial peptides, Reg3b and Reg3g, in the intestinal epithelium, which modulated the microbiome by decreasing and increasing the amount of Bacteroides and Lactobacillus, respectively. Additionally, 1Z1 up-regulated intestinal interleukin (IL)-22 expression. IL-22 deficiency abolished the protective effects of 1Z1 in ethanol-induced liver and intestinal damage, suggesting intestinal IL-22 as a crucial mediator for 1Z1-mediated protection in the AH mouse model. Collectively, our results indicate that TLR7 signaling exerts protective effects in the AH mouse model and that a TLR7 ligand, 1Z1, holds therapeutic potential for the treatment of AH.

Alcohol-associated liver disease (ALD) is caused by chronic and excessive consumption of alcohol. The disease ranges from alcohol-associated fatty liver to alcoholic hepatitis (AH), fibrosis, cirrhosis, and hepatocellular carcinoma (HCC) (1). Alcohol-associated fatty liver is considered reversible and nonprogressive. Nearly 35% of heavy alcohol drinkers develop AH, and up to 40% of severe AH patients die within 6 mo (2). AH patients who survive may progress to alcohol-associated cirrhosis. Treatment options for AH involve the use of corticosteroids and have remained largely unchanged since the early 1970s. Unfortunately, not all patients respond to corticosteroids, and the benefits are temporary in responders (1, 2). Early liver transplant has been shown to be superior to medical management for severe AH, but it still has limitations and can only be considered in a highly selective group of patients (1, 2). Thus, the identification of a better molecular therapeutic target for ALD is a significantly unmet medical need for the development of effective therapies for AH.Previous studies have demonstrated the involvement of Toll-like receptors (TLRs), including TLR2, TLR4, and TLR9, in the development of ALD (3–8). In addition to the direct effect of alcohol and its metabolite, acetaldehyde, in hepatocytes, ethanol intake affects the function of the intestinal epithelial barrier. Chronic alcohol consumption disrupts intestinal tight junction integrity and increases gut permeability, resulting in elevated bacterial lipopolysaccharide (LPS) concentrations in the portal and systemic circulation (4). Translocated LPS activates resident hepatic macrophages, known as Kupffer cells, via TLR4, thereby promoting ALD (1, 2, 7, 8). Other TLRs, such as TLR2 and TLR9, recognize gram-positive bacterial components and bacterial CpG-DNA, respectively (3, 4). Furthermore, TLR2, TLR9, and MyD88 are required for the development of the preclinical AH murine model (5), whereas TLR4 and TLR9 exert protective effects against intestinal inflammation (9, 10).TLR7 signaling has been shown to be protective against liver fibrosis in mice (11). Tlr7^−/− mice exhibit augmented cholestasis and carbon tetrachloride (CCl₄)-induced liver fibrosis (11). TLR7 signaling also induces IFN-α production in dendritic cells (DCs), followed by interleukin (IL)-1 receptor antagonist (IL-1Ra) induction in Kupffer cells. IL-1Ra suppresses IL-1-induced hepatic stellate cell (HSC) activation, resulting in inhibition of liver fibrosis (11). Among the TLRs, TLR3 and TLR7 activation has been reported to ameliorate some liver diseases (11, 12). However, a major disadvantage of the currently available synthetic ligands for TLR3 and TLR7, such as poly I:C, imiquimod, and R848, is the excessive induction of proinflammatory cytokines (3, 4). Thus, developing agents without undesirable adverse effects is of great clinical interest.IL-22 is a hepatoprotective cytokine produced by T helper (Th) 17 cells, Th22 cells, γδ T cells, natural killer (NK) T cells, and innate lymphoid cells (ILCs) (13). Exogenous administration of IL-22 has a profound effect on tissue repair following liver injury via the promotion of proliferation and inhibition of apoptosis in hepatocytes of mouse models of AH (14), liver fibrosis, and drug- and LPS-induced liver injury. Also, IL-22 promotes tissue repair in the intestines and is protective against intestinal epithelial damage and inflammation (13). These findings suggest that IL-22 may suppress ALD via the maintenance of intestinal barrier function, thereby preventing increased intestinal permeability and bacterial translocation due to intestine-derived microbial products that promote ethanol-induced liver injury (15, 16).Here, we have developed a synthetic TLR7 ligand, 1Z1, that possesses antiinflammatory effects via IL-22 induction and that is devoid of systemic toxicity after oral administration (17–19). Treatment with 1Z1 has already been reported to be effective for allergic encephalomyelitis, arthritis, dextran sodium sulfate (DSS)-induced colitis, and type I diabetes in mice (17–20). We hypothesize that targeting TLR7 activation may be an effective treatment strategy for ALD. Our experimental results demonstrate that 1Z1 oral administration inhibits ethanol-induced liver and intestinal damage and that these beneficial effects are due to intestinal IL-22 induction in an AH murine model.     

Effects of Several Androgens and Steroid Metabolites on Erythropoietin Production in the Isolated Perfused Dog Kidney

In an attempt to clarify the role of thekidney in the action of several androgensand steroid metabolites on erythropoietin(ESF) production, ESF titers were measured in perfusates of isolated kidneysfrom dogs previously exposed to 4-hrhypoxia and perfused with blood containing testosterone (Test), 5-17-hydroxyandrostan-3-one (5DHT), 5-17-hydroxyandrostan-3-one (5DHT),19-nortestosterone (19-nor), oxymetholone(Oxy), fluoxymesterone (Fluoxy), 3-hydroxy-5-pregnane, 11,20-dione(3OH5preg), or 3-hydroxy-5-pregnane-20-one (3OH-5 preg). ESFlevels in the perfusates were assayed inexhypoxic polycythemic mice. Test,5DHT, oxy, fluoxy, and 3OH5-pregwere found to produce a significant increase in ESF levels in the kidney perfusates. 5DHT, 19-nor, and 3OH5pregfailed to produce a significant elevation inerythropoietin titers in the perfusates ofthe isolated perfused kidneys. These datasuggest that the 4-5 double bond and thespatial configuration of the hydrogen at the5 position as well as the lack of a methylgroup in the 19 position of the basicandrostan nucleus are important in theability of these steroids to stimulate kidneyproduction of ESF.

Submitted on February 12, 1973 Revised on July 5, 1973 Accepted on July 6, 1973