The effect of low-level phthalate mixture on the prevalence of type 2 diabetes mellitus among adults in the US.

Type 2 diabetes mellitus (T2DM) is an important public health issue owing to its rising global prevalence. Phthalates cause various health problems and are currently regulated in developed countries. However, studies on the impacts of low-level phthalate exposure under these regulations on T2DM are limited. This study investigated the impacts of combined and single exposures to phthalates and their alternatives on the prevalence of T2DM in 3,005 adults in the United States. The results indicated a positive joint effect of phthalate mixtures on the prevalence of T2DM. The joint effect was primarily attributed to Di-2-ethylhexyl phthalate (DEHP) metabolites, whereas the contributions of others were limited. This study suggests that, despite the stringent regulations on phthalates, low levels of phthalates, including DEHP, still have joint effects on T2DM. The findings highlight the importance of regulating hazardous phthalates and the need for safer alternatives to reduce public health risks.

KHMDS/Triglyme Cryptate as an Alternative to Phosphazene Base in Stereodivergent Pentafluoroethylation of N-Sulfinylimines Using HFC-125.

A protocol for the stereodivergent pentafluoroethylation of N-sulfinylimines using HFC-125 with KHMDS/triglyme has been developed. Both diastereomers of the pentafluoroethylated amines can be selectively synthesized based on the presence or absence of triglyme. This additive-controlled protocol allows the KHMDS/triglyme cryptate to be a straightforward and cheap alternative to previously reported base-controlled stereodivergent trifluoromethylation using potassium hexamethyldisilazide (KHMDS) versus P4-tBu.

Pentafluoroethylation of Carbonyl Compounds Using HFC-125 in a Flow Microreactor System.

The protocol of micro-flow nucleophilic pentafluoroethylation using pentafluoroethane (HC2F5, HFC-125), a nontoxic, inexpensive, and commercially available greenhouse gas, is described. The micro-flow pentafluoroethylation by HFC-125 proceeded smoothly at room temperature or at -10 °C in DMF or toluene in the presence of a potassium base, namely, t-BuOK or KHMDS. A broad range of ketones, aldehydes, and chalcones with various substituted benzene rings were successfully converted to the corresponding pentafluoroethyl carbinols instantly with good to high yields.

Pentafluoroethylation of Carbonyl Compounds by HFC-125 via the Encapsulation of the K Cation with Glymes.

A simple protocol to overcome the explosive pentafluoroethylation of carbonyl compounds by HFC-125 is described. The use of potassium (K) bases with triglyme or tetraglyme as a solvent safely yields the pentafluoroethylation products in good to high yields. The experimental results suggest that an encapsulation of the K cation by glymes as K(glyme)2 inhibits the contact between the K cation and the reactive anionic pentafluoroethyl counterion, preventing their transformation into KF and explosive tetrafluoroethylene (TFE). The generation of sterically demanding [K(G3)2]+ and [K(G4)2]+ is an effective way as an unstable pentafluoroethyl anion reservoir.

Plasma miR-218a-5p as a biomarker for acute cholestatic liver injury in rats and investigation of its pathophysiological roles.

MicroRNAs (miRNA) have received considerable attention as potential biomarkers for drug-induced liver injury. We recently reported that the plasma levels of miR-143-3p and miR-218a-5p increased in severe cholestasis in rats. This study aimed to investigate whether these miRNAs increase in a severity-dependent manner and to elucidate their pathophysiological roles in cholestasis. Male Sprague-Dawley rats were orally administered different doses of α-naphthylisothiocyanate or 4,4-methylenedianiline to induce acute cholestasis. They were also orally administered acetaminophen or thioacetamide to induce hepatocellular injury. We found that plasma miR-143-3p and miR-218a-5p levels increased in a dose-dependent manner in cholestatic rats but not in hepatocellular injury. Bioinformatic analysis provided putative target genes of hsa-miR-218-5p, rno-miR-218a-5p, and mmu-miR-218-5p, among which GNAI2, PPP1CB, and PPP2R5A were experimentally validated as their direct target genes in human cholangiocyte line MMNK-1. Proliferation of MMNK-1 cells was significantly suppressed after overexpression of miR-218-5p and transduction of siRNAs for GNAI2, PPP1CB, and PPP2R5A. In the cholestatic livers of rats, Ppp1cb and Ppp2r5a expression levels decreased, whereas Gnai2 expression levels increased compared with those in vehicle-treated rats, suggesting that Ppp1cb and Ppp2r5a may be under the control of miR-218a-5p in vivo. In conclusion, our data suggest that miR-218(a)-5p is involved in the suppression of cholangiocyte proliferation by inhibiting the expression of PPP1CB and PPP2R5A, thereby contributing to the pathogenesis of cholestasis; and miR-218a-5p leaks into the plasma probably from damaged cholangiocytes in a severity-dependent manner in rats. Therefore, miR-218a-5p overexpression could be one of the underlying mechanisms of acute cholestatic liver injury in rats.

Synthesis of trifluoromethyl ketones by nucleophilic trifluoromethylation of esters under a fluoroform/KHMDS/triglyme system.

A straightforward method that enables the formation of biologically attractive trifluoromethyl ketones from readily available methyl esters using the potent greenhouse gas fluoroform (HCF3, HFC-23) was developed. The combination of fluoroform and KHMDS in triglyme at -40 °C was effective for this transformation, with good yields as high as 92%. Substrate scope of the trifluoromethylation procedure was explored for aromatic, aliphatic, and conjugated methyl esters. This study presents a straightforward trifluoromethylation process of various methyl esters that convert well to the corresponding trifluoromethyl ketones. The tolerance of various pharmacophores under the reaction conditions was also explored.

Unique miRNA profiling of squamous cell carcinoma arising from ovarian mature teratoma: comprehensive miRNA sequence analysis of its molecular background.

Owing to its rarity, the carcinogenesis and molecular biological characteristics of squamous cell carcinoma arising from mature teratoma remain unclear. This study aims to elucidate the molecular background of malignant transformation from the aspects of microRNA (miRNA) profiling. We examined 7 patients with squamous cell carcinoma and 20 patients with mature teratoma and extracted their total RNA from formalin-fixed paraffin-embedded tissues. Then we prepared small RNA libraries and performed comprehensive miRNA sequencing. Heatmap and principal component analysis revealed markedly different miRNA profiling in cancer, normal ovarian and mature teratoma tissues. Then we narrowed down cancer-related miRNAs, comparing paired-cancer and normal ovaries. Comparisons of cancer and mature teratoma identified two markedly upregulated miRNAs (miR-151a-3p and miR-378a-3p) and two markedly downregulated miRNAs (miR-26a-5p and miR-99a-5p). In addition, these findings were validated in fresh cancer tissues of patient-derived xenograft (PDX) models. Moreover, several miRNAs, including miR-151a-3p and miR-378a-3p, were elevated in the murine plasma when tumor tissues were enlarged although miR-26a-5p and miR-99a-5p were not elucidated in the murine plasma. Finally, we performed target prediction and functional annotation analysis in silico and indicated that targets genes of these miRNAs markedly correlated with cancer-related pathways, including 'pathway in cancer' and 'cell cycle'. In conclusion, this is the first study on miRNA sequencing for squamous cell carcinoma arising from mature teratoma. The study identified four cancer-related miRNAs that were considered to be related to the feature of malignant transformation. Moreover, miRNAs circulating in the murine plasma of the PDX model could be novel diagnostic biomarkers.

Asymmetric Mannich reaction between (S)-N-(tert-butanesulfinyl)-3,3,3-trifluoroacetaldimine and malonic acid derivatives. Stereodivergent synthesis of (R)- and (S)-3-amino-4,4,4-trifluorobutanoic acids.

Inorganic as well as organic base catalysis was found to be effective for diastereoselective Mannich additions of malonic acid derivatives to (SS)-N-(tert-butanesulfinyl)-3,3,3-trifluoroacetaldimine. In the presence of catalytic amounts of inorganic bases, n-BuLi or DMAP, the reaction gives the corresponding (R,SS)-ß-aminomalonates in good yield and with diastereoselectivity up to 9/1 dr. In contrast, phosphazene bases favour the formation of the (S,SS)-diastereomer with selectivities as high as 99/1. Simple choosing of an appropriate base catalyst for the Mannich addition reaction allowed us to obtain enantiomerically pure (R)- or (S)-configured 3-amino-4,4,4-trifluorobutanoic acids after hydrolysis and decarboxylation of the corresponding ß-aminomalonates.

Elevated level of urinary tellurium is a potential risk for increase of blood pressure in humans and mice.

BACKGROUND: People worldwide are routinely exposed to tellurium mainly via dietary ingestion. There has been no study to clarify the contribution of tellurium to blood pressure in humans or animals. METHODS: In this cross-sectional study conducted in a general population of 2592 residents in Japan, the associations of urinary tellurium levels with blood pressure and prevalence of hypertension were investigated. The potential sources of tellurium were also investigated. An interventional study in mice confirmed the effect of tellurium exposure on blood pressure. RESULTS: Linear and logistic regression analyses with consideration of confounders including urinary sodium-potassium ratio showed significant positive associations of urinary tellurium level with prevalence of hypertension and blood pressure. Cereals/beans and vegetables/fruits were determined to be potential dietary sources of tellurium exposure. Intermediary analysis suggested that increased intake of cereals/beans, but not that of vegetables/fruits, is positively associated with the tellurium-mediated risk of hypertension. Correspondingly, the mouse study showed that exposure to a putative human-equivalent dose of tellurium via drinking water increased blood pressure with an elevated level of urinary tellurium. The temporally increased blood pressure was decreased to the normal level by a break of tellurium exposure with a reduced level of urinary tellurium. CONCLUSIONS: The interdisciplinary approach provided the first evidence that tellurium exposure is a potential risk for increase of blood pressure. Since the human urinary tellurium level in this study is comparable with the levels in general populations in other Asian and European countries in previous studies, exposure to tellurium may be a latent universal risk for hypertension.

Beneficial and adverse effects of dam construction in canal tannery wastewater effluent with a high content of chromium in Hazaribagh, Bangladesh.

BACKGROUND: Blockage to divide downstream canals into upstream canals, into which tannery wastewater including a high concentration of trivalent chromium [Cr(III)] is directly discharged, has been constructed in Hazaribagh, a tannery built-up area in Bangladesh. However, there has been no study to verify the environmental significance of blockage construction for water pollution of Cr in nature. METHODS: Consecutive fixed area monitoring for a total of 164 water samples collected outside and inside Hazaribagh from 2014 to 2023 was carried out to clarify the effects of stagnant and flowable canal water in the presence or absence of blockage on Cr(III) and hexavalent Cr [Cr(VI)] concentrations. RESULTS: Since pollution of Cr(III) and Cr(VI) in Buriganga River (outside Hazaribagh) was not serious, this study then focused on their pollution in canal water (inside Hazaribagh) in the nonblockage period, blockage construction period and blockage destruction period. As expected, the mean Cr(III) concentration in downstream canal water samples in the blockage construction period was more than 98% lower than that in the upstream canal water samples in the same period, while the concentrations were comparable in downstream and upstream canal water samples in the nonblockage period and blockage destruction period. Unexpectedly, the mean concentration of Cr(VI) in the upstream canal water samples in the blockage construction period was 38.6-fold and 3.3-fold higher than that in the downstream canal water samples and the Cr(VI) guideline value by the US-EPA, respectively. CONCLUSION: This study demonstrated for the first time not only a merit of decreased Cr(III) pollution but also a demerit of increased Cr(VI) pollution in stagnant water derived from blockage construction in natural environments. This bitter lesson obtained by the enclosure of Cr(III)-polluted water is globally applicable for water pollution of Cr(III), which is used in various industries including the leather industry.

Elevated arsenic level in fasting serum via ingestion of fish meat increased the risk of hypertension in humans and mice.

Aims: There has been a shortage of human studies to elucidate the association between serum arsenic levels and the prevalence of hypertension. This study multidirectionally investigated associations among arsenic exposure, dietary ingestion, and the risk of hypertension by combined human epidemiological and mouse experimental studies. Methods and results: This study focused on the total arsenic level in fasting serum, a biomarker of arsenic exposure. Associations among ingestion frequencies of 54 diet items of Japanese food separated into six categories, total arsenic level in fasting serum, and the prevalence of hypertension were investigated in 2709 general people in Japan. Logistic regression analysis demonstrated a dose-dependent association between serum arsenic level and hypertension and a positive association between the ingestion of fish meat and hypertension. Further analysis showed that the latter association was fully mediated by increased fasting serum arsenic levels in humans. Similarly, oral exposure to the putative human-equivalent dose of arsenic species mixture with the same ratios in a common fish meat in Japan increased systolic blood pressure and arsenic levels in fasting serum in mice. Conclusion: This interdisciplinary approach suggests that fish-meat ingestion is a potential risk factor for arsenic-mediated hypertension. Because the increased consumption of fish meat is a recent global trend, health risks of the increased ingestion of arsenic via fish meat should be further investigated.

Unexpected associations of long-term and excessive exposure to trivalent chromium with hypertension and glycosuria in male tannery workers.

Serious health hazards including renal, skin and hearing disorders have been reported in Bangladeshi tannery workers (TWs) who were chronically exposed to a large amount of trivalent chromium [Cr(III)]. However, the effects of Cr(III) exposure on the prevalence of hypertension and the prevalence of glycosuria in TWs remain unknown. Since the Cr level in toenails is an established marker reflecting long-term exposure to Cr(III) in humans, the associations of Cr levels in toenails with the prevalence of hypertension and the prevalence of glycosuria in male tannery and non-tannery office workers (non-TWs) in Bangladesh were investigated in this study. The mean toenail Cr level in non-TWs (0.5 µg/g, n = 49) was comparable to that in the general population reported previously. Mean Cr levels in TWs with a low toenail Cr level (5.7 µg/g, n = 39) and those with a high toenail Cr level (298.8 µg/g, n = 61) were >10-fold and >500-fold higher, respectively, than that in non-TWs. Our univariate and multivariate analyses indicated that the prevalence of hypertension and the prevalence of glycosuria in TWs with a high toenail Cr level, but not in TWs with a low toenail Cr level, were significantly lower than those in non-TWs. This study showed for the first time that long-term and excessive exposure to Cr(III) that is more than >500-fold but not >10-fold higher than the usual exposure level could decrease the prevalence of hypertension and the prevalence of glycosuria in TWs. Thus, this study revealed unexpected effects of exposure to Cr(III) on health.

Vascular endothelium as a target tissue for short-term exposure to low-frequency noise that increases cutaneous blood flow.

Harmful health effects of exposure to low-frequency noise (LFN) defined as noise with frequencies at ≤100 Hz on the circulatory system have been a concern. However, there has been no study on the effects of exposure to LFN on the circulatory system with consideration of its frequencies and decibels. In this study, the effects of short-term exposure to broad-band LFNs and their pure-tone components (pure-tone LFNs) on cutaneous blood flow in the extremities including the hands were investigated. In our fieldwork study, we first sampled some kinds of common broad-band LFNs. Our human study then showed that broad-band LFN with a narrower frequency range more strongly increased cutaneous blood flow than did broad-band LFN with a wider frequency range. Pure-tone LFNs of 70-100 Hz at ≤85 dB(Z), but not pure-tone LFNs exceeding 100 Hz, further increased levels of cutaneous blood flow. Our wavelet-transform spectrum analysis of cutaneous blood flow next revealed that the nitric oxide (NO)-dependent and -independent vascular activities of the vascular endothelium were specifically increased by exposure to pure-tone LFN. Our animal study again indicated that exposure to pure-tone LFN increased cutaneous blood flow in mice with impairments of bilateral inner ears as well as cutaneous blood flow in control mice, suggesting a limited effect of inner ear function on the LFN-mediated increase in cutaneous blood flow. The NO-dependent suppressive effect of pure-tone LFN on cutaneous blood flow was confirmed by inhibition of vascular endothelial activity through intravenous injection of an NO inhibitor in wild-type mice. Taken together, the results of this study demonstrated that the vascular endothelium is a target tissue of LFN and that NO is an effector of the LFN-mediated increase in cutaneous blood flow. Since improvement of peripheral circulation could generally promote human health, short-term exposure to LFN may be beneficial for health.

Exploration of small RNA biomarkers for testicular injury in the serum exosomes of rats.

Testicular injury is often observed in drug development. Serum hormones are usually used as noninvasive biomarkers for testicular injury; however, their sensitivities are low. Therefore, it is difficult to monitor testicular injury in drug development. In recent years, molecules in body fluid exosomes have attracted attention as biomarkers for diseases. In this study, small RNAs in serum exosomes were analyzed to identify noninvasive biomarkers of testicular injury in rats, which are often used in preclinical drug development. The rat models of testicular injury were prepared by a single oral administration of 2000 mg/kg ethylene glycol monomethyl ether, in which spermatocyte degeneration and Sertoli cell vacuolation were observed, or 400 mg/kg carbendazim, in which Sertoli cell vacuolation and seminiferous tubule dilation were observed. Serum exosomal small RNA-seq analysis of these models was performed. The analysis identified 3 small RNAs that fluctuated in common between the models, and miR-423-5p and miR-128-3p were selected as candidate markers. For evaluating these candidate markers in other testicular injury models, the models were prepared by a single oral administration of 60 mg/kg 1,3-dinitrobenzene or 500 mg/kg nitrofurazone, and spermatocyte degeneration and Sertoli cell vacuolation were observed. In qPCR analysis, these exosomal miRNAs were upregulated in all models except for the 1,3-dinitrobenzene model, in which severe hemolysis was observed. By contrast, these miRNAs in whole serum extracts did not significantly change in any of the models. In conclusion, we identified miR-423-5p and miR-128-3p in serum exosomes as noninvasive biomarkers for testicular injury in rats.

A scrutiny of circulating microRNA biomarkers for drug-induced tubular and glomerular injury in rats.

Drug-induced acute kidney injury (AKI) is a frequent cause of adverse drug reaction. Serum creatinine (CRE) and blood urea nitrogen (BUN) are widely used as standard biomarkers for kidney injury; however, the sensitivity and specificity are considered to be low. In recent years, circulating microRNA (miRNAs) have been attracting considerable attention as novel biomarkers for organ injury, but there are currently no established miRNA biomarkers for drug-induced AKI. The present study aimed to identify plasma miRNAs that may enable early and specific detection of drug-induced tubular and glomerular injury through next-generation sequencing analysis. Six-week old male Sprague-Dawley (SD) rats were intravenously administered cisplatin (CSP, 6 mg/kg) and gentamicin (GEN, 120 mg/kg) to induce tubular injury. To create glomerular injury models, puromycin (PUR, 120 mg/kg) and doxorubicin (DOX, 7.5 mg/kg) were intravenously administered, and these models were always accompanied by tubular damage. Small RNA-sequencing was performed to analyze time-dependent changes in the plasma miRNA profiles. The cluster analyses showed that there were distinct plasma miRNA profiles according to the types of injury, and the changes reflected the progress of renal damages. In the differential analysis, miR-3473 was specifically up-regulated in the glomerular injury models. miR-143-3p and miR-122-5p were commonly down-regulated in all models, and the changes were earlier than the traditional biomarkers, such as plasma CRE and BUN. These data indicated that changes in the specific miRNAs in plasma may enable the early and sensitive detection of tubular and glomerular injuries. The present study suggests the potential utility of plasma miRNAs in the early and type-specific detection of drug-induced AKI.

Identification of Specific MicroRNA Biomarkers in Early Stages of Hepatocellular Injury, Cholestasis, and Steatosis in Rats.

Recently, studies on circulating microRNAs (miRNAs) as potential biomarkers of drug-induced liver injury (DILI) have received increasing attention. It has been demonstrated that miR-122 and miR-192, which are liver enriched, could be potential biomarkers of DILI; however, these miRNAs cannot discern types of injuries. In the present study, we comprehensively analyzed time-dependent plasma miRNA profiles in rats with drug- or chemical-induced hepatocellular injury, cholestasis, and steatosis with high-throughput miRNA sequencing. To enable the comparison of miRNA expression levels between DILI models with different severity and peak time of injuries, the stages of injury were defined as early, middle, and late, according to cluster patterns of miRNA expression profiles. Through differential analysis, we characterized miRNAs that were specifically up- or down-regulated in each DILI model. Several miRNAs were dramatically changed earlier than traditional biomarkers such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST). For example, in an acetaminophen (APAP)-induced hepatocellular injury model, plasma let-7b-5p was up-regulated as early as 3 h after dosing, whereas a significant change in ALT level was observed at 12 h. We then focused on the DILI type-specific miRNAs in plasma that were up-regulated at the early stage of injury. RT-qPCR analysis validated that let-7b-5p and miR-1-3p for hepatocellular injury, miR-143-3p and miR-218a-5p for cholestasis, and miR-320-3p for steatosis models showed significant increases in the early stage of the injuries. The present study suggests the utility of miRNAs as specific biomarkers for the early detection of DILI.

Organic base-catalyzed stereodivergent synthesis of (R)- and (S)-3-amino-4,4,4-trifluorobutanoic acids.

Organic base-catalyzed reaction of (S)-N-tert-butanesulfinyl (3,3,3)-trifluoroacetaldimine with dialkyl malonates was found to be effective for synthesis of both (S,S(S)) and (R,S(S)) ß-aminomalonates in high yield with good to excellent diastereoselectivity (76-98% de). The products of this Mannich reaction provide direct access to ß-trifluoromethyl-ß-alanine of either (R) or (S) absolute configuration.

Asymmetric catalysis with self-organized chiral lanthanum complexes: practical and highly enantioselective epoxidation of alpha,beta-unsaturated ketones.

A highly efficient and practical method for obtaining alpha,beta-epoxy ketones with high optical purities was developed. The chiral lanthanum complex self-organized in situ from lanthanum triisopropoxide, (R)-BINOL, triarylphosphine oxide, and alkyl hydroperoxide (1:1:1:1) was found to catalyze the epoxidation of alpha,beta-unsaturated ketones with tert-butyl hydroperoxide or cumene hydroperoxide at room temperature to give the corresponding epoxy ketones in high enantioselectivities (up to >99% enantiomeric excess (ee)). A remarkably high asymmetric amplification, a positive nonlinear effect, was observed in the epoxidation of chalcone, which strongly suggests the formation of a dinuclear peroxide-involved mu-complex as the active catalyst.