In situ 3D X-ray imaging of water distribution in each layer of a membrane electrode assembly of a polymer electrolyte fuel cell.

In situ 3D computed tomography imaging with statistical analysis successfully revealed the water accumulation and drainage characteristics in the stacked gas diffusion layers (GDLs) and membrane electrode assembly (MEA) of a polymer electrolyte fuel cell. Efficient water drainage at the interface between the cathode GDL and MEA was confirmed upon supplying oxygen to the cathode.

Hybrid distributed Bragg reflector laser on Si with a transfer printed InAs/GaAs quantum dot amplifier.

We demonstrate a hybrid integrated laser by transfer printing an InAs/GaAs quantum dot (QD) amplifier on a Si waveguide with distributed Bragg reflectors (DBRs). The QD waveguide amplifier of 1.6 mm long was patterned in the form of an airbridge with the help of a spin-on-glass sacrificial layer and precisely integrated on the silicon-on-insulator (SOI) waveguide by pick-and-place assembly using an elastomer stamp. Laser oscillation was observed around the wavelength of 1250 nm with a threshold current of 47 mA at room temperature and stable operation up to 80°C. Transfer printing of the long QD amplifiers will enable the development of various hybrid integrated laser devices that leverage superior properties of QDs as laser gain medium.

Diurnal Variation of Brain Activity in the Human Suprachiasmatic Nucleus.

The suprachiasmatic nucleus (SCN) is the central clock for circadian rhythms. Animal studies have revealed daily rhythms in the neuronal activity in the SCN. However, the circadian activity of the human SCN has remained elusive. In this study, to reveal the diurnal variation of the SCN activity in humans, we localized the SCN by employing an areal boundary mapping technique to resting-state functional images and investigated the SCN activity using perfusion imaging. In the first experiment (n = 27, including both sexes), we scanned each participant four times a day, every 6 h. Higher activity was observed at noon, while lower activity was recorded in the early morning. In the second experiment (n = 20, including both sexes), the SCN activity was measured every 30 min for 6 h from midnight to dawn. The results showed that the SCN activity gradually decreased and was not associated with the electroencephalography. Furthermore, the SCN activity was compatible with the rodent SCN activity after switching off the lights. These results suggest that the diurnal variation of the human SCN follows the zeitgeber cycles of nocturnal and diurnal mammals and is modulated by physical lights rather than the local time.

Translational enhancement of target endogenous mRNA in mammalian cells using programmable RNA-binding pentatricopeptide repeat proteins.

Programmable protein scaffolds are invaluable in the development of genome engineering tools. The pentatricopeptide repeat (PPR) protein is an attractive platform for RNA manipulation because of its programmable RNA-binding selectivity, which is determined by the combination of amino acid species at three specific sites in the PPR motif. Translation is a key RNA regulatory step that determines the final gene expression level and is involved in various human diseases. In this study, designer PPR protein was used to develop a translational enhancement technique by fusion with the translation initiation factor eIF4G. The results showed that the PPR-eIF4G fusion protein could activate the translation of endogenous c-Myc and p53 mRNAs and control cell fate, indicating that PPR-based translational enhancement is a versatile technique applicable to various endogenous mRNAs in mammalian cells. In addition, the translational enhancement was dependent on both the target position and presence of eIF4G, suggesting the presence of an unknown translation activation mechanism.

Gain-switched pulse generation of 5.3†ps from 30†GHz-modulation-bandwidth 1270†nm DFB laser diode.

We generated gain-switched pulses via electrical pulse excitations in a 1270 nm distributed feedback (DFB) laser diode (LD) with a direct-modulation bandwidth of 30 GHz. The measurements revealed short-pulse widths of 5.3 and 8.8 ps with and without chirp compensation, via a single-mode optical fiber. The 5.3 ps pulses exhibited a spectral width of 0.40 nm (spectral bandwidth of 71 GHz), yielding a time-bandwidth product of 0.38. Although the gain-switched pulses in DFB LDs inherently contain linear and nonlinear chirp, optimized pumping conditions enable generation of nearly transform-limited ps pulses after linear chirp compensation.

Highlights of the 14th Japan Bioanalysis Forum Symposium.

The 14th Japan Bioanalysis Forum Symposium was held at Tower Hall Funabori, Japan from 1-3 March 2023. The conference theme, 'Bringing Together - the Expertise of Bioanalysis', aimed to enable people from various fields to gather, learn and collaborate together for the common goal of delivering medicines to patients faster. Approximately 360 participants from various fields, including pharmaceutical industries, contractors, academia and regulatory authorities, gathered at an in-person symposium which had an online participation option, for the first time in 4 years. The symposium offered a wide range of topics including ICH M10, new modalities, biomarkers, immunogenicity, electronization and patient-centric sampling. The latest research results were provided from domestic and overseas scientists. This report summarizes the major topics.

Impact of frequency and duration of freeze-dried inactivated tissue culture hepatitis A vaccine (Aimmugen®) vaccination on antibody titers; a japanese cross-sectional study.

BACKGROUND: The effect of the timing of additional doses and the long-term persistence of lyophilized inactivated tissue culture hepatitis A (HA) vaccine (Aimmugen®) on antibodies is unknown. METHODS: A single-center, cross-sectional, observational study was conducted in collaboration with the Japan Air Self-Defense Force, whose personnel were immunized with Aimmugen® when deployed to endemic areas. Patients who consented to this study after a medical examination with blood sampling between June 2022 and February 2023 were included; HA-IgG level in the residual serum was measured using the chemiluminescent immunoassay method. The exact vaccination history was investigated based on immunization records maintained by the Ministry of Defense, and a questionnaire was used to collect confounding factors. RESULTS: Of the 181 participants observed, 49 were in the unvaccinated group, and 132 were in the vaccinated group. Out of the vaccinated group, 6.8 % received either one or two doses, 40.9 % received three doses, and 52.3 % received more than four doses. IgG antibody titers (S/CO value) in each group (0, 1 or 2, 3, and over 4) increased in a frequency-dependent manner, with those vaccinated over four times showing significantly higher IgG antibody titers than all other groups (0.19 ± 0.10 vs 3.66 ± 3.00 vs 7.63 ± 3.57 vs 10.57 ± 1.86, respectively). When the number of months elapsed from the last vaccination to the date of blood collection in each group was plotted against IgG antibody titer, the slope of the regression line flattened out from a decreasing trend in the order 1 or 2, 3, over 4. CONCLUSIONS: Three doses of Aimmugen® are efficacious, but four or more doses induce more robust and sustained antibody production. Additionally, four or more doses may be effective when there is a need to ensure long-term immunity or risk of prolonged exposure.

In vivo recording of suprachiasmatic nucleus dynamics reveals a dominant role of arginine vasopressin neurons in circadian pacesetting.

The central circadian clock of the suprachiasmatic nucleus (SCN) is a network consisting of various types of neurons and glial cells. Individual cells have the autonomous molecular machinery of a cellular clock, but their intrinsic periods vary considerably. Here, we show that arginine vasopressin (AVP) neurons set the ensemble period of the SCN network in vivo to control the circadian behavior rhythm. Artificial lengthening of cellular periods by deleting casein kinase 1 delta (CK1δ) in the whole SCN lengthened the free-running period of behavior rhythm to an extent similar to CK1δ deletion specific to AVP neurons. However, in SCN slices, PER2::LUC reporter rhythms of these mice only partially and transiently recapitulated the period lengthening, showing a dissociation between the SCN shell and core with a period instability in the shell. In contrast, in vivo calcium rhythms of both AVP and vasoactive intestinal peptide (VIP) neurons in the SCN of freely moving mice demonstrated stably lengthened periods similar to the behavioral rhythm upon AVP neuron-specific CK1δ deletion, without changing the phase relationships between each other. Furthermore, optogenetic activation of AVP neurons acutely induced calcium increase in VIP neurons in vivo. These results indicate that AVP neurons regulate other SCN neurons, such as VIP neurons, in vivo and thus act as a primary determinant of the SCN ensemble period.

Development and validation of qPCR methods for nucleic acid biomarkers as a drug development tool: points to consider.

Nucleic acid (NA) biomarkers play critical roles in drug development. However, the global regulatory guidelines for assessing quantification methods specific to NA biomarkers are limited. The validation of analytical methods is crucial for the use of biomarkers in clinical and post-marketing evaluations of drug efficacy and adverse reactions. Given that quantitative polymerase chain reaction (qPCR) and reverse transcription qPCR (RT-qPCR) methods are the gold standards for the quantification of NA biomarkers, the Biomarker Analytical Method Validation Study Group in Japan has discussed considerations and made recommendations for the development and validation of qPCR- and RT-qPCR-based analytical methods for endogenous NA biomarkers as drug development tools. This white paper aims to contribute to the global harmonization of NA biomarker assay validation.

Long days restore regular estrous cyclicity in mice lacking circadian rhythms.

Many female mammals have recurring cycles of ovulation and sexual behaviors that are regulated by reproductive hormones and confer reproductive success. In addition to sexual behaviors, circadian behavioral rhythms of locomotor activity also fluctuate across the estrous cycle in rodents. Moreover, there is a bidirectional relationship between circadian rhythms and estrous cyclicity since mice with disrupted circadian rhythms also have compromised estrous cycles resulting in fewer pregnancies. In the present study, we assessed whether extending day length, which alters circadian rhythms, normalizes estrous cyclicity in mice. We found that Period (Per) 1/2/3 triple knockout (KO) mice, that have disabled canonical molecular circadian clocks, have markedly disrupted estrous cycles. Surprisingly, extending the day length by only 2 h per day restored regular 4- or 5-day estrous cycles to Per1/2/3 KO mice. Longer days also induced consistent 4-day, rather than 5-day, estrous cycles in wild-type C57BL/6J mice. These data demonstrate that extending daytime light exposure could be used for enhancing reproductive success.

Optimal bowel resection margin in colon cancer surgery: prospective multicentre cohort study with lymph node and feeding artery mapping.

Background: There are no standardised criteria for the 'regional' pericolic node in colon cancer, which represents a major cause of the international uncertainty regarding the optimal bowel resection margin. This study aimed to determine 'regional' pericolic nodes based on prospective lymph node (LN) mapping. Methods: According to preplanned in vivo measurements of the bowel, the anatomical distributions of the feeding artery and LNs were determined in 2996 stages I-III colon cancer patients who underwent colectomy with resection margin >10 cm at 25 institutions in Japan. Findings: The mean number of retrieved pericolic nodes was 20.9 (standard deviation, 10.8) per patient. In all patients except seven (0.2%), the primary feeding artery was distributed within 10 cm of the primary tumour. The metastatic pericolic node most distant from the primary tumour was within 3 cm in 837 patients, 3-5 cm in 130 patients, 5-7 cm in 39 patients and 7-10 cm in 34 patients. Only four patients (0.1%) had pericolic lymphatic spread beyond 10 cm; all of whom had T3/4 tumours accompanying extensive mesenteric lymphatic spread. The location of metastatic pericolic node did not differ by the feeding artery's distribution. Postoperatively, none of the 2996 patients developed recurrence in the remaining pericolic nodes. Interpretation: The pericolic nodes designated as 'regional' were those located within 10 cm of the primary tumours, which should be fully considered when determining the bowel resection margin, even in the era of complete mesocolic excision. Funding: Japanese Society for Cancer of the Colon and Rectum.

Circadian rhythm of PERIOD2::LUCIFERASE expression in the trigeminal ganglion of mice.

Introduction: The trigeminal nerve conveys delicate sensations such as warmth, pain, and tactile pressure in the oral and facial regions, and most trigeminal afferent cell bodies are located in the trigeminal ganglion. Our previous study has shown that sensations in trigeminal nerve innervated areas, specifically in the maxillofacial region, exhibit diurnal variation and that sensitivity changes time-dependently. In this study, we aimed to clarify the rhythm of expression of clock gene in the trigeminal ganglion of mice to elucidate the mechanism of circadian regulation in the same area. Methods: Immunohistochemistry examined the expression of the PER2 protein in the suprachiasmatic nucleus and trigeminal ganglion of wild-type mice. To measure gene expression as bioluminescence, PERIOD2::LUCIFERASE knock-in (PER2::LUC) mice were used. Unilateral trigeminal ganglion and brain sections including the suprachiasmatic nucleus were incubated ex vivo. Bioluminescence levels were then measured using a highly sensitive photodetector. The same experiments were then conducted with Cry1 gene-deficient (Cry1-/- ) or Cry2 gene-deficient (Cry2-/- ) mice. Results: In the trigeminal ganglion, immunohistochemistry localized PER2 protein expression within the neuronal cell body. Mouse trigeminal ganglion ex vivo tissues showed distinct circadian oscillations in PER2::LUC levels in all genotypes, wild-type, Cry1-/- , and Cry2-/- . The period was shorter in the trigeminal ganglion than in the suprachiasmatic nucleus; it was shorter in Cry1-/- and longer in Cry2-/- mice than in the wild-type mice. Conclusion: The expression of Per2 in neurons of the trigeminal ganglion in ex vivo culture and the oscillation in a distinct circadian rhythm suggests that the trigeminal ganglion is responsible for the relay of sensory inputs and temporal gating through autonomous circadian oscillations.

Optimal blue light irradiation conditions for the treatment of acne vulgaris in a mouse model.

BACKGROUND: Although blue light is one of the therapeutic approaches used to treat acne vulgaris (AV), there is no consensus on its effectiveness. As a result, it is not recommended in the major acne vulgaris treatment guidelines. OBJECTIVE: The goal of this study was to look into the mechanism, safety, and efficacy of blue light therapy. We achieved this by examining the pathological response, inflammation, and depth of light penetration in a mouse model of cystic AV. METHODS: The aims of the study were addressed by exposing the mice to light with a wavelength of 415 nm under four different irradiation conditions. The exposure was done for five consecutive days followed by a no irradiation period of 72 h. RESULTS: Blue light treatment was most effective when irradiation was performed at 100 mW/cm2 for 20 min for five consecutive days. Inflammatory responses emerged 72 h after the final irradiation dose was administered. These responses were not associated with apoptosis as cleaved caspase-3 staining revealed no significant increases in apoptosis in the skin under any of the tested conditions. Blue light reached the superficial layer of the acne cyst at 5% of the total irradiation power and was attenuated by half for every 50 µm of progress through the cyst. CONCLUSION: In conclusion, blue light could control severe dermatologic inflammatory responses; therefore, it can be used to irradiate AV with high inflammation levels on a daily basis until improvement is observed. In addition, porphyrin, a metabolite of Cutibacterium acnes, and reactive oxygen species generated by the surrounding skin tissue may have essential roles in AV treatment.

Nomogram as a novel predictive tool for lymph node metastasis in T1 colorectal cancer treated with endoscopic resection: a nationwide, multicenter study.

BACKGROUND AND AIMS: Since 2009, the Japanese Society for Cancer of the Colon and Rectum guidelines have recommended that tumor budding and submucosal invasion depth, in addition to lymphovascular invasion and tumor grade, be included as risk factors for lymph node metastasis (LNM) in patients with T1 colorectal cancer (CRC). In this study, a novel nomogram was developed and validated by usirge-scale, real-world data, including the Japanese Society for Cancer of the Colon and Rectum risk factors, to accurately evaluate the risk of LNM in T1 CRC. METHODS: Data from 4673 patients with T1 CRC treated at 27 high-volume institutions between 2009 and 2016 were analyzed for LNM risk. To prepare a nonrandom split sample, the total cohort was divided into development and validation cohorts. Pathologic findings were extracted from the medical records of each participating institution. The discrimination ability was measured by using the concordance index, and the variability in each prediction was evaluated by using calibration curves. RESULTS: Six independent risk factors for LNM, including submucosal invasion depth and tumor budding, were identified in the development cohort and entered into a nomogram. The concordance index was .784 for the clinical calculator in the development cohort and .790 in the validation cohort. The calibration curve approached the 45-degree diagonal in the validation cohort. CONCLUSIONS: This is the first nomogram to include submucosal invasion depth and tumor budding for use in routine pathologic diagnosis based on data from a nationwide multi-institutional study. This nomogram, developed with real-world data, should improve decision-making for an appropriate treatment strategy for T1 CRC.

Urate Transporter ABCG2 Function and Asymptomatic Hyperuricemia: A Retrospective Cohort Study of CKD Progression.

RATIONALE & OBJECTIVE: Treatment of asymptomatic hyperuricemia is not commonly implemented. However, it is unclear whether urate deposition that begins during asymptomatic hyperuricemia can induce nephropathy. Dysfunction of ATP-binding cassette subfamily G member 2 (ABCG2), a urate efflux transporter, leads to elevated serum uric acid concentration (SUA). We investigated the association between asymptomatic hyperuricemia and decreased estimated glomerular filtration rate (eGFR), and the impact of ABCG2 on this relationship. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: 1,885 Japanese adults undergoing routine health care follow-up between 2007 and 2017 who had eGFR ≥60 mL/min/1.73 m2, of which 311 had asymptomatic hyperuricemia (SUA >7.0 mg/dL). Study participants were classified into 3 categories of estimated ABCG2 function (full, 75%, and ≤50% function). PREDICTORS: Baseline SUA and estimated ABCG2 function. OUTCOME: Change in eGFR over time. ANALYTICAL APPROACH: Linear mixed-effect models were used to analyze the relationship between asymptomatic hyperuricemia, ABCG2 function, and eGFR decline. RESULTS: Asymptomatic hyperuricemia was negligibly associated with eGFR decline overall. However, among those with eGFR 60-89 mL/min/1.73 m2 and ≤50% ABCG2 function, eGFR decline was associated with asymptomatic hyperuricemia (P = 0.03). ABCG2 was not associated with eGFR reductions when the SUA was <6.0 mg/dL. Among participants with SUA ≥6.0 mg/dL and eGFR 60-89 mL/min/1.73 m2, ≤50% ABCG2 function was associated with approximately 1.2-fold faster eGFR decline compared with fully functional ABCG2 (P = 0.02). Among the participants with SUA ≥6.0 mg/dL and eGFR 60-89 mL/min/1.73 m2, the adjusted eGFR slopes (given as mean ± standard error of the mean, in mL/min/1.73 m2 per year) were -0.946 ± 0.049, -1.040 ± 0.046, and -1.148 ± 0.069 for full, 75%, and ≤50% ABCG2 function, respectively. LIMITATIONS: Lack of measurement of urinary urate and uremic toxins that are known to be transported by ABCG2, and no independent validation cohort. CONCLUSIONS: Asymptomatic hyperuricemia was not associated with eGFR decline, except when in the presence of ≤50% ABCG2 function. PLAIN-LANGUAGE SUMMARY: The urate transporter ABCG2 is a protein that regulates serum urate concentrations; when dysfunctional, it can lead to elevated serum concentrations of this compound (ie, hyperuricemia). Although persistent hyperuricemia induces gout and kidney injury, the effects on organs during the asymptomatic phase have yet to be established. Therefore, to clarify the relationship between ABCG2, asymptomatic hyperuricemia, and kidney function, we conducted a retrospective cohort study of 1,885 healthy participants, including 311 participants with asymptomatic hyperuricemia. We found that the coexistence of asymptomatic hyperuricemia and severe ABCG2 dysfunction was associated with the age-dependent decline in kidney function. We concluded that asymptomatic hyperuricemia represents a risk factor for chronic kidney disease, at least in individuals with highly dysfunctional ABCG2. This new finding highlights the potential importance of ABCG2 in the pathogenesis of hyperuricemia-induced kidney injury.

Early Initiation of Antitumor Necrosis Factor Therapy Reduces Postoperative Recurrence of Crohn's Disease Following Ileocecal Resection.

BACKGROUND: Postoperative recurrence (POR) of Crohn's disease (CD) is common after surgical resection. We aimed to compare biologic type and timing for preventing POR in adult CD patients after ileocecal resection (ICR). METHODS: We performed a retrospective cohort study of CD patients who underwent an ICR at 2 medical centers. Recurrence was defined by endoscopy (≥ i2b Rutgeerts score) or radiography (active inflammation in neoterminal ileum) and stratified by type and timing of postoperative prophylactic biologic within 12 weeks following an ICR (none, tumor necrosis factor antagonists [anti-TNF], vedolizumab, and ustekinumab). RESULTS: We identified 1037 patients with CD who underwent an ICR. Of 278 (26%) who received postoperative prophylaxis, 80% were placed on an anti-TNF agent (n = 223) followed by ustekinumab (n = 28, 10%) and vedolizumab (n = 27, 10%). Prophylaxis was initiated in 35% within 4 weeks following an ICR and in 65% within 4 to 12 weeks. After adjusting for factors associated with POR, compared with no biologic prophylaxis, the initiation of an anti-TNF agent within 4 weeks following an ICR was associated with a reduction in POR (adjusted hazard ratio, 0.61; 95% CI, 0.40-0.93). Prophylaxis after 4 weeks following an ICR or with vedolizumab or ustekinumab was not associated with a reduction in POR compared with those who did not receive prophylaxis. CONCLUSION: Early initiation of an anti-TNF agent within 4 weeks following an ICR was associated with a reduction in POR. Vedolizumab or ustekinumab, at any time following surgery, was not associated with a reduction in POR, although sample size was limited.

Postoperative recurrence of Crohn's disease is common after ileocecal resection. In this dual-center study, early initiation of an anti-TNF agent within 4 weeks following an ileocecal resection was associated with a reduction in postoperative recurrence of Crohn's disease.

The survival rate of patients with burns induced by explosions was significantly higher than that of common burn cases: A nationwide observational study using the Japan Trauma Data Bank.

BACKGROUNDS: Blast injuries have a variety of mechanisms, with some cases resulting in immediate death and others resulting in burns as a fourth type of blast injury when the energy of the explosion is relatively low. We reported in 2020, as an incidental result, that burns caused by explosions had a higher survival rate than usual burns caused by other mechanisms. The present study confirmed whether or not burns caused by explosions had higher survival rates than those caused by other mechanisms using the Japan Trauma Data Bank (JTDB), a leading nationwide trauma registry in Japan. METHODS: Burn patients registered to the JTDB database from January 2004 to March 2019 were analyzed retrospectively. The 338,744 patients registered to the JTDB database published in 2021 were identified. After exclusion, 7127 patients met the criteria for inclusion in this study. Logistic regression analyses were conducted for in-hospital survival rates using patients with burns, including cases complicated by usual trauma and burned patients without usual trauma. The survival rates by External burn grade AIS98 were compared between the explosion group and other cause groups using burn cases without usual trauma. RESULTS: The cause of the explosion significantly influenced the survival according to logistic regression analyses using burn groups with and without usual trauma. For AIS 4 and 5, we found significant differences between the explosion group and other cause groups in survival rates among burn cases without usual trauma. CONCLUSION: The survival rate of patients with burns induced by explosions was higher than that of common burn cases according to analyses based on a burn grade of AIS98 among burn cases without common trauma. Multivariate analyses also showed that explosion burns had a significantly better outcome than those induced by other causes.

SWOT analysis of noninvasive tests for diagnosing NAFLD with severe fibrosis: an expert review by the JANIT Forum.

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. Nonalcoholic steatohepatitis (NASH) is an advanced form of NAFLD can progress to liver cirrhosis and hepatocellular carcinoma (HCC). Recently, the prognosis of NAFLD/NASH has been reported to be dependent on liver fibrosis degree. Liver biopsy remains the gold standard, but it has several issues that must be addressed, including its invasiveness, cost, and inter-observer diagnosis variability. To solve these issues, a variety of noninvasive tests (NITs) have been in development for the assessment of NAFLD progression, including blood biomarkers and imaging methods, although the use of NITs varies around the world. The aim of the Japan NASH NIT (JANIT) Forum organized in 2020 is to advance the development of various NITs to assess disease severity and/or response to treatment in NAFLD patients from a scientific perspective through multi-stakeholder dialogue with open innovation, including clinicians with expertise in NAFLD/NASH, companies that develop medical devices and biomarkers, and professionals in the pharmaceutical industry. In addition to conventional NITs, artificial intelligence will soon be deployed in many areas of the NAFLD landscape. To discuss the characteristics of each NIT, we conducted a SWOT (strengths, weaknesses, opportunities, and threats) analysis in this study with the 36 JANIT Forum members (16 physicians and 20 company representatives). Based on this SWOT analysis, the JANIT Forum identified currently available NITs able to accurately select NAFLD patients at high risk of NASH for HCC surveillance/therapeutic intervention and evaluate the effectiveness of therapeutic interventions.

Diurnal variations of triglyceride accumulation in mouse and bovine adipocyte-derived cell lines.

Several studies have suggested a strong interaction between the circadian clock and lipid metabolism in mammals. The circadian clock is driven by endogenous cyclic gene expression patterns, commonly referred to as clock genes, and transcription-translation negative feedback loops. Clock genes regulate the transcription of some lipid metabolism-related genes; however, the relationship between the circadian clock and triglyceride (TG) accumulation at the cellular level remains unclear. Here, we evaluated rhythms of intracellular TG accumulation levels as well as the expression of clock genes and lipid metabolism-related genes for 54 h in mouse and bovine adipose-derived cell cultures. To the best of our knowledge, this study represents the first report demonstrating that TG accumulation exhibits diurnal variations, with the pattern differing among cell types. Furthermore, we found that expression of clock genes and corresponding lipid metabolism-related genes exhibited circadian rhythms. Our results suggest that the cellular clock regulates lipid metabolism-related genes to relate circadian rhythms of TG accumulation in each cell type. We anticipate that the amount of fat stored depends on the timing of the supply of glucose-the precursor of fat. The findings of this study will contribute to the advancement of chrono-nutrition.

Highlights of the 13th Japan Bioanalysis Forum Symposium.

Approximately 280 people from pharmaceutical industries, contractors, academic institutions and regulatory authorities attended the 13th Japan Bioanalysis Forum Symposium. The symposium was held via web to prevent the spread of COVID-19 from the 28 February to 2 March 2022. The theme of the symposium was 'All for One Goal', and the event has provided an opportunity for open discussion among researchers with different backgrounds but who share a common goal: "to deliver more effective and safe pharmaceuticals to patients as quickly as possible". The speakers focused on hot topics in bioanalysis, including chromatography, biomarker analysis, cell and gene therapy, COVID-19 and antidrug antibody. This symposium provided a great opportunity for the participants to have meaningful discussions, even though 'on the web' was a limited space.