Postmarket safety communications on drugs approved in Japan: A 25-year analysis.

Drug safety communications (DSCs) are essential tools for communicating important postmarket serious drug safety information to healthcare professionals and patients. Previous studies characterized DSCs issued by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA); however, knowledge about the activities of the Pharmaceuticals and Medical Devices Agency (PMDA)/the Ministry of Health, Labor and Welfare (MHLW) is limited. This study characterized DSCs by the PMDA/MHLW in comparison with previously reported DSCs by the FDA and the EMA. We retrospectively analyzed 37 DSCs of 41 adverse drug reactions (ADRs) for 33 drugs in Japan from 1997 to 2022. Most DSCs were related to non-oncology drugs (30/37, 81.1%), and the median (interquartile range) time from approval to DSC issuance was 19 (10-51) months. Notably, the regulatory review reports and the latest labels before DSC issuance did not describe 16/28 (57.1%) and 12/37 (32.4%) of the ADRs related to DSCs, respectively. Most DSCs resulted in label revisions (36/37, 97.3%) and seven drugs were eventually withdrawn. Some DSC characteristics are similar among the PMDA/MHLW, the FDA, and the EMA; however, the number, contents, and range of new safety issues addressed by DSCs differ among the three jurisdictions. Our study emphasized the importance of continuous efforts to gather postmarket drug safety information because substantial ADRs that led to DSCs were recognized after approval and were associated with critical label revisions and withdrawals. Future studies are required to address global challenges for regulatory harmonization of safety-related regulatory actions.

Analysis of drug-induced liver-related adverse event trend reporting between 1997 and 2019.

AIM: This study aimed to analyze the current trends of drug-induced liver-related adverse events in the Food and Drug Administration Adverse Event Reporting System (FAERS) and Japanese Adverse Drug Event Report (JADER) databases. METHODS: The characteristics of implicated drugs were investigated by analyzing big data on drug-induced liver-related adverse events over the past 20 years in FAERS, comparing drug rankings between the JADER and FAERS databases, and calculating rankings of drugs inducing liver-related adverse events using the Medical Dictionary for Regulatory Activities Terminology. RESULTS: In the 452 272 cases registered in FAERS from 1997 to 2019, warfarin, paracetamol, and adalimumab were the drugs most related to drug-induced liver injury (DILI). In the 38 919 cases registered in JADER from 2004 to 2019, sorafenib, nivolumab, and herbal extracts were the drugs most related to DILI. No associations were found between the top 30 drugs in either of the two databases. Notably, the number of drug-induced liver-related adverse event reports and total adverse events has sharply increased in recent years. CONCLUSIONS: Although liver-related adverse events are largely caused by host immunity and other constitutional factors, differences in primary diseases, countries, and historical backgrounds lead to differences in the number of reports. Securing an appropriate database and a mechanism to collect real-time information on the frequency of adverse drug reactions is warranted.

[Usefulness of Metal Artifact-reduced Reconstruction for Image-guided Brachytherapy for Cervical Cancer].

PURPOSE: To evaluate the usefulness of single-energy metal artifact reduction (SEMAR) for target delineation in brachytherapy for cervical cancer patients with metal hip implants. MATERIAL AND METHODS: A series of four definitive brachytherapy sessions in the same patient was analyzed. At each brachytherapy session, the identical set of computed tomography images was subjected with or without SEMAR treatment. For both SEMAR-treated and -untreated sets, five radiation oncologists delineated the high-risk clinical target volume (HR-CTV), bladder, and rectum, for which the volume, Dice coefficient, and the dose volume parameters were compared between SEMAR-treated and -untreated datasets. RESULTS: The bladder volume was significantly greater in the SEMAR-treated datasets compared with the SEMAR-untreated datasets. Importantly, for the bladder, Dice coefficient among five radiation oncologists was significantly higher for the SEMAR-treated datasets compared with the SEMAR-untreated datasets. These effects of SEMAR treatment were not evident for HR-CTV and the rectum. CONCLUSIONS: These data indicate that SEMAR treatment contributes to improve delineation of the bladder in brachytherapy for cervical cancer patients with metal hip implants.

Possible differences in the mechanism of malignant transformation of HaCaT cells by arsenite and its dimethyl metabolites, particularly dimethylthioarsenics.

BACKGROUND: As a confirmed human carcinogen, arsenic can cause skin cancer, lung cancer, etc. However, its carcinogenic mechanism is still unclear. In recent years, the oxidative stress hypothesis has become widely accepted. In mammals it has been found that arsenic can be converted to dimethylarsinous acid (DMAIII) and dimethylmonothioarsinic acid (DMMTAV) through a series of methylation and redox reactions. DMAIII and DMMTAV are highly toxic. METHODS: Human keratinocytes (HaCaT) were exposed to different concentrations of NaAsO2 (IAsIII), DMMTAV and DMAIII for 24 h. Reactive oxygen species (hydrogen peroxide and superoxide), oxidative damage markers (8-hydroxydeoxyguanosine and malondialdehyde), and antioxidant markers (glutathione and superoxide dismutase) were measured. In addition, sulfane sulfurs were measured in HaCaT cells and a cell-free system. RESULTS: In the DMMTAV and DMAIII treatment groups, the levels of hydrogen peroxide and superoxide in HaCaT cells were higher than in the IAsIII treatment groups at the same dose. Levels of 8-OHdG and MDA in the DMMTAV and DMAIII treatment groups were also higher than those in the IAsIII treatment groups at the same dose. However, in the DMMTAV and DMAIII treatment groups, the levels of GSH and SOD activity were lower than that in the IAsIII treatment groups. In DMMTAV-treated HaCaT cells, sulfane sulfurs were produced. Further, it was found that DMMTAV could react with DMDTAV to form persulfide in the cell-free system, which may explain the mechanism of the formation of sulfane sulfurs in DMMTAV-treated HaCaT cells. CONCLUSIONS: DMMTAV and DMAIII more readily induce reactive oxygen species (ROS) and cause oxidative damage in HaCaT cells than inorganic arsenic. Further, the persulfide formed by the reaction of DMMTAV and DMDTAV produced from the metabolism of DMMTAV may induce a stronger reductive defense mechanism than GSH against the intracellular oxidative stress of DMMTAV. However, the cells exposed to arsenite are transformed by the continuous nuclear translocation of Nrf2 due to oxidative stress, and the persulfide from dimethylthioarsenics may promote Nrf2 by the combination with thiol groups, especially redox control key protein, Keap1, eventually cause nuclear translocation of sustained Nrf2.

[Dose Distribution Optimization in Combined Intracavitary and Interstitial Brachytherapy for Cervical Cancer].

PURPOSE: Hybrid inverse treatment planning optimization (HIPO) is a new optimization tool for brachytherapy. We verified its utility using treatment plans for combined intracavitary and interstitial brachytherapy in cervical cancer. MATERIALS & METHODS: We compared the manually optimized plan and the plan optimized using HIPO. The plan using HIPO was optimized with three different methods: needle only, tandem and needle, and all applicators. The dose volume histogram (DVH) parameters such as D90 of high risk clinical target volume (HR-CTV) and D2cc of OAR (rectum, sigmoid colon and bladder) were used to evaluate each treatment plan. RESULTS: The D90 of HR-CTV in most plans was received more than 600 cGy. In addition, the D2cc of OAR also was less than the tolerance dose on the average of all plans. However, the D2cc of the rectum and bladder treatment plans optimized only with needles was significantly higher than other plans. CONCLUSIONS: The treatment plans used in clinical practice and obtained by HIPO have similar dose distributions and DVH parameters. Moreover, the time needed to create treatment plan was reducing by HIPO. We suggest that HIPO will be an effective tool in treatment planning.

Prefoldin protects neuronal cells from polyglutamine toxicity by preventing aggregation formation.

Huntington disease is caused by cell death after the expansion of polyglutamine (polyQ) tracts longer than ∼40 repeats encoded by exon 1 of the huntingtin (HTT) gene. Prefoldin is a molecular chaperone composed of six subunits, PFD1-6, and prevents misfolding of newly synthesized nascent polypeptides. In this study, we found that knockdown of PFD2 and PFD5 disrupted prefoldin formation in HTT-expressing cells, resulting in accumulation of aggregates of a pathogenic form of HTT and in induction of cell death. Dead cells, however, did not contain inclusions of HTT, and analysis by a fluorescence correlation spectroscopy indicated that knockdown of PFD2 and PFD5 also increased the size of soluble oligomers of pathogenic HTT in cells. In vitro single molecule observation demonstrated that prefoldin suppressed HTT aggregation at the small oligomer (dimer to tetramer) stage. These results indicate that prefoldin inhibits elongation of large oligomers of pathogenic Htt, thereby inhibiting subsequent inclusion formation, and suggest that soluble oligomers of polyQ-expanded HTT are more toxic than are inclusion to cells.

Rabring7 degrades c-Myc through complex formation with MM-1.

We have reported that a novel c-Myc-binding protein, MM-1, repressed E-box-dependent transcription and transforming activities of c-Myc and that a mutation of A157R in MM-1, which is often observed in patients with leukemia or lymphoma, abrogated all of the repressive activities of MM-1 toward c-Myc, indicating that MM-1 is a novel tumor suppressor. MM-1 also binds to the ubiquitin-proteasome system, leading to degradation of c-Myc. In this study, we identified Rabring7, a Rab7-binding and RING finger-containing protein, as an MM-1-binding protein, and we found that Rabring7 mono-ubiquitinated MM-1 in the cytoplasm without degradation of MM-1. Rabring7 was also found to bind to c-Myc and to ubiquitinate c-Myc in a threonine 58-dependent manner. When c-Myc was co-transfected with MM-1 and Rabring7, c-Myc was degraded. Furthermore, it was found that c-Myc was stabilized in MM-1-knockdown cells even when Rabring7 was transfected and that Rabring7 was bound to and co-localized with MM-1 and c-Myc after MM-1 and Rabring7 had been translocated from the cytoplasm to the nucleus. These results suggest that Rabring7 stimulates c-Myc degradation via mono-ubiquitination of MM-1.

Prefoldin subunits are protected from ubiquitin-proteasome system-mediated degradation by forming complex with other constituent subunits.

The molecular chaperone prefoldin (PFD) is a complex comprised of six different subunits, PFD1-PFD6, and delivers newly synthesized unfolded proteins to cytosolic chaperonin TRiC/CCT to facilitate the folding of proteins. PFD subunits also have functions different from the function of the PFD complex. We previously identified MM-1α/PFD5 as a novel c-Myc-binding protein and found that MM-1α suppresses transformation activity of c-Myc. However, it remains unclear how cells regulate protein levels of individual subunits and what mechanisms alter the ratio of their activities between subunits and their complex. In this study, we found that knockdown of one subunit decreased protein levels of other subunits and that transfection of five subunits other than MM-1α into cells increased the level of endogenous MM-1α. We also found that treatment of cells with MG132, a proteasome inhibitor, increased the level of transfected/overexpressed MM-1α but not that of endogenous MM-1α, indicating that overexpressed MM-1α, but not endogenous MM-1α, was degraded by the ubiquitin proteasome system (UPS). Experiments using other PFD subunits showed that the UPS degraded a monomer of PFD subunits, though extents of degradation varied among subunits. Furthermore, the level of one subunit was increased after co-transfection with the respective subunit, indicating that there are specific combinations between subunits to be stabilized. These results suggest mutual regulation of protein levels among PFD subunits and show how individual subunits form the PFD complex without degradation.

Syntheses and characterization of new nickel coordination polymers with 4,4'-dipyridylsulfide. Dynamic rearrangements of one-dimensional chains responding to external stimuli: temperature variation and guest releases/re-inclusions.

Crystal structures and dynamic rearrangements of one-dimensional coordination polymers with 4,4'-dipyridylsulfide (dps) have been studied. Reaction of Ni(NO(3))(2)·6H(2)O with dps in EtOH yielded [Ni(dps)(2)(NO(3))(2)] ·EtOH (1), which had channels filled with guest EtOH molecules among the four Ni(dps)(2) chains. This coordination polymer reversibly transformed the channel structure responding to temperature variations. Immersion of 1 in m-xylene released guest EtOH molecules to yield a guest-free coordination polymer [Ni(dps)(2)(NO(3))(2)] (2a), which was also obtained by treatment of Ni(NO(3))(2)·6H(2)O with dps in MeOH. On the other hand, removal of the guest molecules from 1 upon heating at 130 °C under reduced pressure produced a guest-free coordination polymer [Ni(dps)(2)(NO(3))(2)] (2b). Although the 2a and 2b guest-free coordination polymers have the same formula, they showed differences in the assembled structures of the one-dimensional chains. Exposure of 2b to EtOH vapor reproduced 1, while 2a did not convert to 1 in a similar reaction. Reaction of Ni(NO(3))(2)·6H(2)O with dps in acetone provided [Ni(dps)(NO(3))(2)(H(2)O)] ·Me(2)CO (4) with no channel structure. When MeOH or acetone was used as a reaction solvent, the [Ni(dps)(2)(NO(3))(2)] · (guest molecule) type coordination polymer, which was observed in 1, was not formed. Nevertheless, the reaction of Ni(NO(3))(2)·6H(2)O with dps in MeOH/acetone mixed solution produced [Ni(dps)(2)(NO(3))(2)]·0.5(MeOH·acetone) (5), which has an isostructural Ni-dps framework to 1.

A new redox-active coordination polymer with cobalticinium dicarboxylate.

A new two-dimensional coordination polymer with cobalticinium 1,1'-dicarboxylate (ccdc) incorporated in the framework has been prepared, the ccdc functioning as unique monoanionic dicarboxylate ligands. The compound shows a high redox activity based on the ccdc units.

Dynamic coordination polymers with 4,4'-oxybis(benzoate): reversible transformations of nano- and nonporous coordination frameworks responding to present solvents.

Reversible construction of a nanoporous framework from a nonporous framework has been found in the zinc(II) coordination polymer with 4,4'-oxybis(benzoate) (oba). [Zn(2)(oba)(2)(dmf)(2)].2DMF (1), which has 1 nm scale channels, transforms to the nonporous coordination polymer [Zn(oba)(H(2)O)] (2) with the loss of the open framework. Compound 2 on treatment with DMF reversibly yields nanoporous compound 1.

A new Zn(II) coordination polymer with 4-pyridylthioacetate: assemblies of homo-chiral helices with sulfide sites.

A coordination polymer [Zn(pyta)(OH)] (pyta = 4-pyridylthioacetate), was synthesized and structurally characterized; it is constructed by an alternating assembly of two types of homo-chiral helices, [Zn-OH] and [Zn-pyta], in which the sulfide moieties are fastened in the latter columns.