Mound-like Epiretinal Material: Its Short-term Changes and Association with Posterior Vitreous Detachment.

PURPOSE: To describe clinical characteristics of a retinal finding termed mound-like epiretinal material (MOLEM), and distinguish it from epiretinal proliferation, a similar epiretinal finding previously described in various pathologies. METHODS: Five eyes from five patients were retrospectively identified from medical records. Clinical findings and images, including fundus photographs and optical coherence tomography (OCT), were reviewed. RESULTS: All eyes displayed mound-like material with uniform and low-to-moderate reflectivity on an otherwise intact retinal surface detected on OCT. No eyes presented with concurrent pathology typically observed in cases of epiretinal proliferation, such as lamellar/full-thickness macular hole, epiretinal membrane, vitreomacular traction, or uveitis. Two eyes exhibited central serous chorioretinopathy, but there was no association of MOLEM with serous retinal detachment. In three out of five eyes, MOLEM appeared simultaneously with posterior vitreous detachment (PVD). Some lesions underwent irregular transformations over months and occasionally disappeared. While all cases were monitored without intervention, no visual decline or complications attributed to MOLEM were detected. CONCLUSION: MOLEM represents a novel clinical finding, characterized by transient morphological changes without symptoms and potential association with PVD. It may occur in eyes lacking macular diseases linked with epiretinal proliferation, a similar yet distinct lesion. The incidence, etiology, and clinical significance of MOLEM warrant further investigation by accumulating comparable cases, although the lesion appears benign and self-limiting.

Excess suicides in Japan: A three-year post-pandemic assessment of gender and age disparities.

This study offers an in-depth analysis of Japan's suicide trends three years after the COVID-19 outbreak. Using data from the National Police Agency (January 2010-May 2023), we examined suicide rates across genders and age groups. Employing the quasi-Poisson regression, we predicted monthly death counts. Findings indicate a steady rise in female suicides from April 2020 to January 2023. Notably, male cohorts aged 50-59 and over 80 in 2022 displayed heightened death rates. While these trends may reflect the impacts of the pandemic, it is essential to consider other factors, including socio-economic changes, to fully understand the context of Japan's suicide patterns.

Cell surface architecture of the cultivated DPANN archaeon Nanobdella aerobiophila.

The DPANN archaeal clade includes obligately ectosymbiotic species. Their cell surfaces potentially play an important role in the symbiotic interaction between the ectosymbionts and their hosts. However, little is known about the mechanism of ectosymbiosis. Here, we show cell surface structures of the cultivated DPANN archaeon Nanobdella aerobiophila strain MJ1T and its host Metallosphaera sedula strain MJ1HA, using a variety of electron microscopy techniques, i.e., negative-staining transmission electron microscopy, quick-freeze deep-etch TEM, and 3D electron tomography. The thickness, unit size, and lattice symmetry of the S-layer of strain MJ1T were different from those of the host archaeon strain MJ1HA. Genomic and transcriptomic analyses highlighted the most highly expressed MJ1T gene for a putative S-layer protein with multiple glycosylation sites and immunoglobulin-like folds, which has no sequence homology to known S-layer proteins. In addition, genes for putative pectin lyase- or lectin-like extracellular proteins, which are potentially involved in symbiotic interaction, were found in the MJ1T genome based on in silico 3D protein structure prediction. Live cell imaging at the optimum growth temperature of 65°C indicated that cell complexes of strains MJ1T and MJ1HA were motile, but sole MJ1T cells were not. Taken together, we propose a model of the symbiotic interaction and cell cycle of Nanobdella aerobiophila.IMPORTANCEDPANN archaea are widely distributed in a variety of natural and artificial environments and may play a considerable role in the microbial ecosystem. All of the cultivated DPANN archaea so far need host organisms for their growth, i.e., obligately ectosymbiotic. However, the mechanism of the ectosymbiosis by DPANN archaea is largely unknown. To this end, we performed a comprehensive analysis of the cultivated DPANN archaeon, Nanobdella aerobiophila, using electron microscopy, live cell imaging, transcriptomics, and genomics, including 3D protein structure prediction. Based on the results, we propose a reasonable model of the symbiotic interaction and cell cycle of Nanobdella aerobiophila, which will enhance our understanding of the enigmatic physiology and ecological significance of DPANN archaea.

Longitudinal anatomical and visual outcome of macular telangiectasia type 2 in Asian patients.

Limited information regarding the anatomical and visual prognosis of macular telangiectasia (MacTel) type 2 in the Asian population is currently available. Herein, we conducted a retrospective longitudinal analysis of Japanese patients diagnosed with MacTel type 2. Disease progression was evaluated using the Simple MacTel Classification developed by Chew EY et al. in 2023, and its association with visual changes was analyzed. Sixteen eyes of eight Japanese patients were included in the study, with an average follow-up period of 8.2 ± 3.9 years (range, 2.2-14.0). At the initial visit, 7 (44%) and 5 (31%) eyes were classified as Grade 2 (central ellipsoid zone break) and Grade 3 (noncentral pigment), respectively. The proportion of eyes that progressed by 1 or 2-steps in grade after 1, 3, 5, 8, and 12 years was 0%, 14%, 43%, 70%, and 100%, or 0%, 7%, 7%, 30%, and 75%, respectively. The visual acuity significantly deteriorated during the follow-up period, particularly in the two eyes with full-thickness macular holes (FTMH). Three out of 7 patients exhibited low serum serine concentrations, although no apparent correlation with anatomical or visual outcomes was observed. Overall, this cohort demonstrated chronic disease progression, both anatomically and functionally, in eyes with MacTel type 2, with FTMH potentially associated with greater visual loss.

Tumor-associated neutrophils and macrophages exacerbate antidrug IgG-mediated anaphylactic reaction against an immune checkpoint inhibitor.

BACKGROUND: With the increased use of immune checkpoint inhibitors (ICIs), side effects and toxicity are a great concern. Anaphylaxis has been identified as a potential adverse event induced by ICIs. Anaphylaxis is a life-threatening medical emergency. However, the mechanisms and factors that can potentially influence the incidence and severity of anaphylaxis in patients with cancer remain unclear. METHODS: Healthy, murine colon 26, CT26, breast 4T1, EMT6, and renal RENCA tumor-bearing mice were treated with an anti-PD-L1 antibody (clone 10F.9G2). Symptoms of anaphylaxis were evaluated along with body temperature and mortality. The amounts of antidrug antibody and platelet-activating factor (PAF) in the blood were quantified via ELISA and liquid chromatography-mass spectrometry (LC-MS/MS). Immune cells were analyzed and isolated using a flow cytometer and magnetic-activated cell sorting, respectively. RESULTS: Repeated administration of the anti-PD-L1 antibody 10F.9G2 to tumor-bearing mice caused fatal anaphylaxis, depending on the type of tumor model. After administration, antidrug immunoglobulin G (IgG), but not IgE antibodies, were produced, and PAF was released as a chemical mediator during anaphylaxis, indicating that anaphylaxis was caused by an IgG-dependent pathway. Anaphylaxis induced by 10F.9G2 was treated with a PAF receptor antagonist. We identified that neutrophils and macrophages were PAF-producing effector cells during anaphylaxis, and the tumor-bearing models with increased numbers of neutrophils and macrophages showed lethal anaphylaxis after treatment with 10F.9G2. Depletion of both neutrophils and macrophages using clodronate liposomes prevented anaphylaxis in tumor-bearing mice. CONCLUSIONS: Thus, increased numbers of neutrophils and macrophages associated with cancer progression may be risk factors for anaphylaxis. These findings may provide useful insights into the mechanism of anaphylaxis following the administration of immune checkpoint inhibitors in human subjects.

Association between the Co-administration of Histamine H2 Receptor Antagonists and the Effectiveness of Capecitabine in Patients with Colorectal Cancer: Propensity Score Analysis.

Background: The association between the effectiveness of capecitabine and the concomitant administration of gastric acid suppressants remains controversial. We aimed to clarify whether the effectiveness of capecitabine is affected by the co-administration of histamine H2 receptor antagonists (H2RAs) in early-stage colorectal cancer (CRC) patients using real-world data. Methods: This multicenter, retrospective, observational study included consecutive patients with stage II-III CRC who received either capecitabine monotherapy or the CapeOX regimen (capecitabine and oxaliplatin) as adjuvant therapy between January 2009 and December 2014 in Japan. Relapse-free survival (RFS) and overall survival were estimated using the Kaplan-Meier method. Additionally, multivariable Cox proportional hazards model, propensity score adjustment, and inverse probability of treatment weighting analyses were performed. Results: In total, 552 patients were included in this study, of which 30 were co-administered H2RAs. RFS at five years was 76.7% (95% confidence interval [CI]: 57.2-88.1%) and 79.8% (95% CI: 76.0-83.0%) in the H2RA and non-H2RA groups, respectively. Multivariable Cox proportional hazards model and propensity score-adjusted analyses showed that the co-administration of H2RAs was associated with a poor RFS among those receiving capecitabine monotherapy (hazard ratio [HR], 2.01; 95% CI: 0.86-4.70 and HR, 1.81; 95% CI: 0.77-4.22, respectively). In contrast, these results were inconsistent with the group receiving the CapeOX regimen. Conclusions: The study findings suggest that the co-administration of H2RAs may not reduce the effectiveness of capecitabine therapy in patients with early-stage CRC. To confirm this relationship, a prospective study with a pharmacokinetic approach is needed.

Effective Cell Transfection in An Ultrasonically Levitated Droplet for Sustainable Technology.

The levitation methodology, which enables us to operate a contactless reaction without a container, is likely to be a revolutionary technology in the fields of chemistry and biology to reduce the plastic waste in life science laboratories. Here, the authors show that plasmid DNA can be effectively transfected into animal cells in a floating droplet of culture medium levitated using ultrasonic standing waves. The data indicate that there is no significant damage to the plasmid and cells during the levitating transfection time, and the transgene expression efficiency and cellular uptake in the droplet are significantly higher than those in the conventional tube, with and without shaking. These results suggest the consolidation of the endocytic uptake pathway into macropinocytosis, indicating that ultrasonic levitation induced a change in cell characteristics. This study suggests that transfection methodology using ultrasonic levitation has the potential to advance the current experimental procedures in the field of cell engineering, in addition to presenting a revolutionary containerless reactor for sustainable technology.

Proton pump inhibitors affect capecitabine efficacy in patients with stage II-III colorectal cancer: a multicenter retrospective study.

The association between capecitabine efficacy and proton pump inhibitors (PPIs) is controversial. Here, we determined whether co-administration of PPIs affects the real-world effectiveness of capecitabine. This retrospective observational study included consecutive patients with stage II-III colorectal cancer (CRC) who received adjuvant capecitabine monotherapy or CapeOX (capecitabine and oxaliplatin) between January 2009 and December 2014 at nine participating institutions. The primary endpoint was the difference in relapse-free survival (RFS) between patients who received PPIs and those who did not and was estimated using the Kaplan-Meier method. Overall survival (OS) was the secondary endpoint. Multivariable analysis of RFS and OS was performed using a Cox proportional hazards model, propensity score adjustment, and inverse probability of treatment weighting (IPTW) analyses. Data from 606 patients were evaluated, 54 of whom had received a PPI. PPI-treated patients tended to have poorer RFS and OS than patients treated without PPIs. The hazard ratio for RFS with capecitabine monotherapy was 2.48 (95% confidence interval: 1.22-5.07). These results were consistent with sensitivity analyses performed using propensity score adjustment and IPTW methods. Co-administration of PPIs may reduce the effectiveness of capecitabine and negatively impact patients with stage II-III CRC.

Clinical Efficacy and Safety of Arbekacin against Pneumonia in Febrile Neutropenia: A Retrospective Study in Patients with Hematologic Malignancies.

BACKGROUND: Arbekacin (ABK) is an aminoglycoside that exhibits anti-methicillin-resistant Staphylococcus aureus (MRSA) and anti-Pseudomonas aeruginosa activities. Therefore, for patients with febrile neutropenia (FN) and concurrent pneumonia suspected to be caused by MRSA, ABK may be sufficiently effective even as a single agent. MATERIALS AND METHODS: Patients with hematologic malignancies treated with ABK who met the following criteria were included: 1) fever during neutropenia or functional neutropenia, 2) FN complicated by pneumonia, and 3) possible infection by antimicrobial-resistant Gram-positive cocci. RESULTS: This study encompassed 22 episodes involving 19 patients, of which, 15 (68.2%) were successfully treated with ABK. Of the nine episodes showing inadequate response to other anti-MRSA drugs, eight were successfully treated with ABK. Grade 2 or worse adverse events included acute kidney injury (13.6%) and increased transaminase levels (9.1%). CONCLUSION: The present study demonstrated that ABK is effective and safe in patients with FN and concurrent pneumonia caused by antimicrobial-resistant Gram-positive cocci. ABK may also be effective in patients who are unresponsive to other anti-MRSA drugs. Therefore, ABK may be beneficial in the treatment of pneumonia caused by antimicrobial-resistant Gram-positive cocci in patients with FN.

Correlations of mRNA Levels among Efflux Transporters, Transcriptional Regulators, and Scaffold Proteins in Non-Small-Cell Lung Cancer.

Multidrug resistance (MDR) due to enhanced drug efflux activity of tumor cells can severely impact the efficacy of antitumor therapies. We recently showed that increased activity of the efflux transporter P-glycoprotein (P-gp) associated with activation of Snail transcriptional regulators may be mediated mainly by moesin in lung cancer cells. Here, we aimed to systematically evaluate the relationships among mRNA expression levels of efflux transporters (P-gp, breast cancer resistance protein (BCRP), and multidrug resistance-associated protein 2 (MRP2)), scaffold proteins (ezrin (Ezr), radixin (Rdx), and moesin (Msn); ERM proteins), and SNAI family members (Snail, Slug, and Smac) in clinical lung cancer and noncancer samples. We found high correlations between relative (cancer/noncancer) mRNA expression levels of Snail and Msn, Msn and P-gp, Slug and MRP2, and Smuc and BCRP. These findings support our previous conclusion that Snail regulates P-gp activity via Msn and further suggest that Slug and Smuc may contribute to the functional regulation of MRP2 and BCRP, respectively, in lung cancer cells. This trial is registered with UMIN000023923.

Deep neural network for the determination of transformed foci in Bhas 42 cell transformation assay.

Bhas 42 cell transformation assay (CTA) has been used to estimate the carcinogenic potential of chemicals by exposing Bhas 42 cells to carcinogenic stimuli to form colonies, referred to as transformed foci, on the confluent monolayer. Transformed foci are classified and quantified by trained experts using morphological criteria. Although the assay has been certified by international validation studies and issued as a guidance document by OECD, this classification process is laborious, time consuming, and subjective. We propose using deep neural network to classify foci more rapidly and objectively. To obtain datasets, Bhas 42 CTA was conducted with a potent tumor promotor, 12-O-tetradecanoylphorbol-13-acetate, and focus images were classified by experts (1405 images in total). The labeled focus images were augmented with random image processing and used to train a convolutional neural network (CNN). The trained CNN exhibited an area under the curve score of 0.95 on a test dataset significantly outperforming conventional classifiers by beginners of focus judgment. The generalization performance of unknown chemicals was assessed by applying CNN to other tumor promotors exhibiting an area under the curve score of 0.87. The CNN-based approach could support the assay for carcinogenicity as a fundamental tool in focus scoring.

Wheezing Characteristics and Predicting Reactivity to Inhaled ß2-Agonist in Children for Home Medical Care.

Background: Given that wheezing is treated with inhaled ß2-agonists, their effect should be reviewed before the condition becomes severe; however, few methods can currently predict reactivity to inhaled ß2-agonists. We investigated whether preinhalation wheezing characteristics identified by lung sound analysis can predict reactivity to inhaled ß2-agonists. Methods: In 202 children aged 10-153 months, wheezing was identified by auscultation. Lung sounds were recorded for 30 s in the chest region on the chest wall during tidal breathing. We analyzed the wheezing before and after ß2-agonist inhalation. Wheezing was displayed as horizontal bars of intensity defined as a wheeze power band, and the wheezing characteristics (number, frequency, and maximum intensity frequency) were evaluated by lung sound analysis. The participants were divided into two groups: non-disappears (wheezing did not disappear after inhalation) and disappears (wheezing disappeared after inhalation). Wheezing characteristics before ß2-agonist inhalation were compared between the two groups. The characteristics of wheezing were not affected by body size. The number of wheeze power bands of the non-responder group was significantly higher than those of the responder group (P < 0.001). The number of wheeze power bands was a predictor of reactivity to inhaled ß2-agonists, with a cutoff of 11.1. The 95% confidence intervals of sensitivity, specificity, and positive and negative predictive values were 88.8, 42, 44, and 81.1% (P < 0.001), respectively. Conclusions: The number of preinhalation wheeze power bands shown by lung sound analysis was a useful indicator before treatment. This indicator could be a beneficial index for managing wheezing in young children.

Comparison of effectiveness and complications in trabeculotomy with phacoemulsification between ab externo and ab interno using a spatula-shaped microhook.

To compare the short-term surgical effectiveness and safety profile of trabeculotomy ab externo and ab interno with microhook in terms of the recovery of visual acuity. A retrospective chart review was performed on patients who underwent trabeculotomy combined with phacoemulsification and lens implantation at Asahi General Hospital, with 6 months of follow-up. The patients treated by trabeculotomy were classified into two groups depending on the surgical procedures: ab interno with Tanito microhook (TMH) and ab externo with rigid probe trabeculotome (LOT). The demographics, preoperative and postoperative intraocular pressure (IOP), number of medications (Med), best-corrected visual acuity (BCVA), surgical-induced astigmatism (SIA), and postoperative complications were analyzed at pre-operation, and 1 week and 1-6 months post-operation. Fifty-two eyes of 38 Japanese patients underwent TMH and 42 eyes of 32 patients underwent LOT. The decreases in IOP and Med from the baseline were significant at all time points in both groups (p < 0.001), but there were no significant differences between the two groups. BCVA improved significantly in TMH and LOT after the operation (p < 0.001). BCVA and SIA significantly improved, mostly at 1 week in TMH, compared with LOT (p = 0.02 and 0.003). Hyphema and IOP spike exceeding 30 mmHg (spike) occurred in 11% and 6% of participants in TMH, and 33% and 26% of participants in LOT, respectively. Hyphema and IOP spike occurred more frequently in the LOT than in the TMH group (p = 0.01 and 0.005). Ab interno trabeculotomy showed similar IOP-lowering effects as ab externo, but had less postoperative complications.

Effects of Sex and Seasonal Climatic Changes on the Risk of Incidence of Anti-EGFR Therapy-Induced Rash in Cancer Patients: A Retrospective Study.

Background and Objectives: Seasonal climatic changes may affect the development of the rash that is characteristic of treatment with anti-epidermal growth factor receptor (EGFR) antibodies. We evaluated the association between seasons and rash incidence among patients with cancer. Materials and Methods: Data from patients with colorectal or head and neck cancer treated with cetuximab or panitumumab during summer (S group; n = 34) or winter (W group; n = 37) between June 2014 and February 2019 were collected to retrospectively examine patient characteristics and rash incidence ≤ 8 weeks after treatment initiation. Results: Rashes were observed in 73.5% (n = 25) and 78.4% (n = 29) and grade 3 rashes were observed in 17.6% (n = 6) and 2.7% (n = 1) of the patients in the S and W groups, respectively. The incidence of grade ≥ 2 rashes in males in the S group was higher than that in the rest of the patient groups (p < 0.01). Conclusions: The higher incidence of skin rashes in males during summer might be attributed to the effects of ultraviolet light, lack of skincare, male hormones, and secretion of anti-EGFR antibodies in sweat. These findings highlight the need for research on preventive measures for such rashes.

Impact of One-Carbon Metabolism-Driving Epitranscriptome as a Therapeutic Target for Gastrointestinal Cancer.

One-carbon (1C) metabolism plays a key role in biological functions linked to the folate cycle. These include nucleotide synthesis; the methylation of DNA, RNA, and proteins in the methionine cycle; and transsulfuration to maintain the redox condition of cancer stem cells in the tumor microenvironment. Recent studies have indicated that small therapeutic compounds affect the mitochondrial folate cycle, epitranscriptome (RNA methylation), and reactive oxygen species reactions in cancer cells. The epitranscriptome controls cellular biochemical reactions, but is also a platform for cell-to-cell interaction and cell transformation. We present an update of recent advances in the study of 1C metabolism related to cancer and demonstrate the areas where further research is needed. We also discuss approaches to therapeutic drug discovery using animal models and propose further steps toward developing precision cancer medicine.

Low-Dose Olanzapine Plus Granisetron and Dexamethasone for Carboplatin-Induced Nausea and Vomiting in Patients with Thoracic Malignancies: A Prospective Multicenter Phase II Trial.

BACKGROUND: Olanzapine is an inexpensive and durable agent for the treatment of chemotherapy-induced nausea and vomiting and is also superior to neurokinin-1 receptor antagonists in the control of nausea. This study aimed to investigate the efficacy and safety of a low dose of 5 mg olanzapine plus granisetron and dexamethasone for treatment of carboplatin (CBDCA)-induced nausea and vomiting in patients with thoracic malignancies. MATERIALS AND METHODS: We conducted a prospective, open-label, single-arm, multicenter, phase II trial in four centers in Japan. Registered patients were scheduled to receive area under the curve (AUC) ≥5 mg/mL per minute of CBDCA and had never received moderately to highly emetogenic chemotherapy. Patients received olanzapine 5 mg/day orally after supper for 4 days, in combination with granisetron and dexamethasone. Primary endpoint was complete response (CR; no emesis and no use of rescue medication) rate during the overall phase (0-120 hours). RESULTS: Between February 2018 and June 2020, 51 patients were enrolled, and 50 patients were evaluated. The CR rates in the overall (0-120 hours), acute (0-24 hours), and delayed phases (24-120 hours) were 94.0%, 100%, and 94.0%, respectively. No grade 3 or higher adverse effects of olanzapine were observed. CONCLUSION: Prophylactic antiemetic therapy with a low dose of 5 mg olanzapine plus granisetron and dexamethasone showed durable efficacy with an acceptable safety profile. This three-drug combination appears to be a reasonable treatment approach in patients with thoracic malignancies receiving an AUC ≥5 mg/mL per minute of CBDCA-based regimen. Clinical trial identification number: UMIN000031267. IMPLICATIONS FOR PRACTICE: The results of this phase II trial indicated that the prophylactic administration of low-dose of 5 mg olanzapine combined with granisetron and dexamethasone has promising activity with acceptable safety profile in patients with thoracic malignancy receiving high-dose carboplatin chemotherapy.

Potentiometric Determination of Circulating Glycoproteins by Boronic Acid End-Functionalized Poly(ethylene glycol)-Modified Electrode.

Despite tremendous complexity in glycan structure, sialic acid (SA) provides an analytically accessible index for glycosylation, owing to its uniquely anionic nature and glycan-chain terminal occupation. Taking advantage of boronic acid (BA) based SA-recognition chemistry, we here demonstrate a label-free, no enzymatic, potentiometric determination of fetuin, a blood-circulating glycoprotein implicated in physiological and various pathological states. A phenylboronic acid (PBA) ω-end-functionalized poly(ethylene glycol) (PEG) with an α-tethering unit bearing pendent alkyne groups was "grafted-to" a gold electrode modified with 11-azide-undecathiol by a copper-catalyzed azide-alkyne cycloaddition reaction. Using the electrode, fetuin was potentiometrically detectable with a µM-order-sensitivity that is comparable to what is found in blood-collected specimen. Our finding may have implications for developing a remarkably economic hemodiagnostic technology with ease of downsizing and mass production.

Immuno-Surgical Management of Pancreatic Cancer with Analysis of Cancer Exosomes.

Exosomes (EXs), a type of extracellular vesicles secreted from various cells and especially cancer cells, mesenchymal cells, macrophages and other cells in the tumor microenvironment (TME), are involved in biologically malignant behaviors of cancers. Recent studies have revealed that EXs contain microRNAs on their inside and express proteins and glycolipids on their outsides, every component of which plays a role in the transmission of genetic and/or epigenetic information in cell-to-cell communications. It is also known that miRNAs are involved in the signal transduction. Thus, EXs may be useful for monitoring the TME of tumor tissues and the invasion and metastasis, processes that are associated with patient survival. Because several solid tumors secrete immune checkpoint proteins, including programmed cell death-ligand 1, the EX-mediated mechanisms are suggested to be potent targets for monitoring patients. Therefore, a companion therapeutic approach against cancer metastasis to distant organs is proposed when surgical removal of the primary tumor is performed. However, EXs and immune checkpoint mechanisms in pancreatic cancer are not fully understood, we provide an update on the recent advances in this field and evidence that EXs will be useful for maximizing patient benefit in precision medicine.

Hereditary pancreatitis model by blastocyst complementation in mouse.

The application of pluripotent stem cells is expected to contribute to the elucidation of unknown mechanism of human diseases. However, in vitro induction of organ-specific cells, such as pancreas and liver, is still difficult and the reproduction of their disorders in a model has been unfeasible. To study the mechanism of human hereditary pancreatitis (HP), we here performed the blastocyst complementation (BC) method. In the BC method, mouse embryonic stem (ES) cells harboring CRISPR/CAS9-mediated mutations in the Prss1 gene were injected into blastocysts with deficient Pdx1 gene, which is a critical transcription factor in the development of pancreas. The results showed that trypsin was activated extremely in Prss1-mutant mice. This implied that the mouse phenotype mimics that of human HP and that the BC method was useful for the reproduction and study of pancreatic disorders. The present study opens the possibility of investigating uncharacterized human diseases by utilizing the BC method.

State-of-the-Art Technology of Model Organisms for Current Human Medicine.

Since the 1980s, molecular biology has been used to investigate medical field mechanisms that still require the use of crude biological materials in order to achieve their necessary goals. Transcription factor-induced pluripotent stem cells are used in regenerative medicine to screen drugs and to support lost tissues. However, these cells insufficiently reconstruct whole organs and require various intact cells, such as damaged livers and diabetic pancreases. For efficient gene transfer in medical use, virally mediated gene transfers are used, although immunogenic issues are investigated. To obtain efficient detective and diagnostic power in intractable diseases, biological tools such as roundworms and zebrafish have been found to be useful for high-throughput screening (HST) and diagnosis. Taken together, this biological approach will help to fill the gaps between medical needs and novel innovations in the field of medicine.