Real-world evaluation of osteoporotic fractures using the Japan Medical Data Vision database.

In Japanese patients who experienced an osteoporotic fracture, 10.8% and 18.6% had a subsequent fracture within 1 and 2 years of follow-up, respectively. Although the burden of hip and vertebral fractures has been reported widely, we found that patients with non-hip non-vertebral (NHNV) fractures had a 26% higher risk of subsequent fracture than patients with hip fractures; therefore, NHNV fractures should also be considered an important risk factor for subsequent fracture. INTRODUCTION: To investigate imminent risk and odds of subsequent osteoporotic fractures and associated risk factors in patients who experienced an initial osteoporotic fracture. METHODS: Patients aged ≥ 50 years with ≥ 1 osteoporotic fracture were analyzed from Japan's Medical Data Vision (MDV) database of claims from acute-care hospitals (January 2012-January 2017). Multivariable models were constructed to explore the impact of key comorbidities and medications on the subsequent fracture risk: Cox proportional hazards model for time to subsequent fracture and logistic regression models for odds of subsequent fracture within 1 and 2 years from index fracture. RESULTS: In total, 32,926 patients were eligible with a median follow-up duration of 12.3 months. The percentage of patients experiencing subsequent fractures was 14.1% across the study duration, and 10.8% and 18.6% in patients with 1 and 2 years of follow-up, respectively. In the Cox proportional hazards model, patients with vertebral or NHNV index fractures had a higher subsequent fracture risk than patients with a hip index fracture (adjusted hazard ratio [aHR] 1.11 and 1.26, respectively); subsequent fracture risk was lower in males than females (aHR 0.89). Patients with baseline claims for tranquilizers and glucocorticoids had a higher subsequent fracture risk than those without (aHR 1.14 and 1.08, respectively). Additionally, baseline claims for anti-Parkinson's medications, alcoholism, and stage 4/5 chronic kidney disease were significantly associated with higher odds of subsequent fracture in the logistic regression models. CONCLUSION: Several clinical and demographic factors were associated with a higher risk and odds of subsequent fracture. This may help to identify patients who should be prioritized for osteoporosis treatment.

Family caregiver burden of patients with osteoporotic fracture in Japan.

INTRODUCTION: Osteoporotic fractures are the most common serious consequence of osteoporosis. Patients who suffer such fractures often require caregiver assistance afterwards. This study characterized the humanistic burden experienced by family caregivers of patients with osteoporotic fractures in Japan. MATERIALS AND METHODS: Family caregivers were defined as individuals who provided non-professional care to an osteoporotic fracture patient (> 50 years old). Caregivers were asked through an online survey panel about their caregiving situation, health-related quality of life (HRQoL), work impairment, and the health status of their patient. The Zarit Caregiver Burden Interview (ZBI-22), 8-item Short Form Health Survey (SF-8), and Work Productivity and Activity Impairment Caregiver version (WPAI-CG) were used to better understand the impact of osteoporotic fracture caregiving. RESULTS: Respondents (n = 309) were family caregivers who were employed (81.6%) and cared for a parent (71.5%). Over 75% of caregivers had HRQoL physical and mental component scores below 50 on SF-8. Although most patients received welfare services (78.3%), the mean ZBI-22 score was 42.2 and 57.0% of caregivers perceived their burden to be moderate or severe (ZBI-22 score ≥ 41). Over half of caregivers changed their employment status due to their caregiving responsibilities and experienced 61.4% overall work impairment. The mean productivity loss for caregivers was estimated to be over 43,000 JPY per week. CONCLUSION: The substantial humanistic and financial burden of caregiving by family members to osteoporotic fracture patients should be considered when evaluating the impact of fragility fractures, disease management and support systems for osteoporosis.

Burden of migraine among Japanese patients: a cross-sectional National Health and Wellness Survey.

BACKGROUND: Limited studies have measured the burden of migraine in Japan. This study aimed at estimating the disease burden of migraine in Japan and identifying factors associated with the burden using the 2017 National Health and Wellness Survey. METHODS: Migraine patients were defined by ICHD-3 like criteria with ≥4 monthly headache days (MHDs), and non-migraine respondents were selected using 1:4 propensity score matching. Multivariate analyses were conducted to compare Health-related Quality of Life (HRQoL), work productivity and activity impairment (WPAI), healthcare resource utilization (HRU) and costs between the two groups, and to identify factors associated with these outcomes in migraine patients. RESULTS: In 30,001 respondents, 378 migraine patients were identified. Compared to matched controls (N = 1512), migraine patients had lower physical (45.17 vs. 49.89), mental (42.28 vs. 47.71) and role/social (37.91 vs. 44.19) component summary scores (p < 0.001). Migraine patients had higher absenteeism (6.4% vs. 2.2%), presenteeism (40.2% vs. 22.5%), total work productivity impairment (44.3% vs. 24.5%), total activity impairment (45.0% vs. 23.9%), indirect costs (1,492,520 JPY vs. 808,320 JPY) and more visits to healthcare providers in the past 6 months (7.23 vs. 3.96) (p < 0.001). More MHDs was associated with worse HRQoL, and higher HRU and indirect costs. CONCLUSIONS: Japanese migraine patients experience an incremental burden. This demonstrates the unmet needs among Japanese migraine patients.

Cationic Defect Engineering for Controlling the Infrared Absorption of Hexagonal Cesium Tungsten Bronze Nanoparticles.

Cesium tungsten bronzes (Cs0.32WO3) have attracted much attention as a near-infrared absorbing material. We report the successful synthesis of highly crystalline and high purity Cs0.32WO3 nanoparticles through a spray pyrolysis route. Careful analyses disclosed the presence of cationic defects, that is, a tungsten deficiency and insufficient Cs doping in the Cs0.32WO3 nanoparticles. These cationic defects can be controlled by facile heat treatment in a mildly reducing atmosphere. In particular, we clarify that the tungsten deficiency is a key factor among the cationic defects to obtain high near-infrared absorption properties. Furthermore, this study clearly demonstrates the precise tunability of the optical properties by means of the lattice constants of the Cs0.32WO3 crystal. The realized range of lattice constants is significantly wider than those previously reported. These findings should contribute to the engineering of Cs0.32WO3 structure and properties.

Anti-factor IXa/X bispecific antibody ACE910 prevents joint bleeds in a long-term primate model of acquired hemophilia A.

ACE910 is a humanized anti-factor IXa/X bispecific antibody mimicking the function of factor VIII (FVIII). We previously demonstrated in nonhuman primates that a single IV dose of ACE910 exerted hemostatic activity against hemophilic bleeds artificially induced in muscles and subcutis, and that a subcutaneous (SC) dose of ACE910 showed a 3-week half-life and nearly 100% bioavailability, offering support for effective prophylaxis for hemophilia A by user-friendly SC dosing. However, there was no direct evidence that such SC dosing of ACE910 would prevent spontaneous bleeds occurring in daily life. In this study, we newly established a long-term primate model of acquired hemophilia A by multiple IV injections of an anti-primate FVIII neutralizing antibody engineered in mouse-monkey chimeric form to reduce its antigenicity. The monkeys in the control group exhibited various spontaneous bleeding symptoms as well as continuous prolongation of activated partial thromboplastin time; notably, all exhibited joint bleeds, which are a hallmark of hemophilia. Weekly SC doses of ACE910 (initial 3.97 mg/kg followed by 1 mg/kg) significantly prevented these bleeding symptoms; notably, no joint bleeding symptoms were observed. ACE910 is expected to prevent spontaneous bleeds and joint damage in hemophilia A patients even with weekly SC dosing, although appropriate clinical investigation is required.

Optical properties of group-3 metal hexaboride nanoparticles by first-principles calculations.

LaB6 nanoparticles are widely used as solar control materials for strong near-infrared absorption and high visible transparency. In order to elucidate the origin of this unique optical property, first-principles calculations have been made for the energy-band structure and dielectric functions of R(III)B6 (R(III) = Sc, Y, La, Ac). On account of the precise assessment of the energy eigenvalues of vacant states in conduction band by employing the screened exchange method, as well as to the incorporation of the Drude term, dielectric functions and various physical properties of LaB6 have been reproduced in excellent agreement with experimental values. Systematic examinations of dielectric functions and electronic structures of the trivalent metal hexaborides have clarified the origin of the visible transparency and the near-infrared plasmon absorption of R(III)B6 nanoparticles.

Improvement in vision-related function with intravitreal aflibercept: data from phase 3 studies in wet age-related macular degeneration.

PURPOSE: To evaluate the effect of intravitreal aflibercept injection on visual function in wet age-related macular degeneration (AMD). DESIGN: Prospective, multicenter, double-masked, active-controlled, parallel-group, randomized phase 3 clinical studies (VEGF Trap-Eye: Investigation of Efficacy and Safety in Wet AMD [VIEW] 1 and 2 [clinicaltrials.gov identifiers, NCT00509795 and NCT00637377, respectively]). PARTICIPANTS: Patients (n=2419) with active, treatment-naïve, exudative AMD. This analysis included patients who received intravitreal aflibercept 2.0 mg every 8 weeks (2q8; n=607) or ranibizumab 0.5 mg every 4 weeks (0.5q4; n=595). INTERVENTION: Patients were randomized 1:1:1:1 to receive intravitreal aflibercept 2q8 (after 3 initial monthly doses), intravitreal aflibercept 2q4, intravitreal aflibercept 0.5q4, or ranibizumab 0.5q4 in the study eye. Patients in the intravitreal aflibercept 2q8 group received a sham injection alternating with active treatment. MAIN OUTCOME MEASURES: The 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) was administered at baseline and at weeks 12, 24, 36, and 52. The NEI VFQ-25 subscale scores were compared between intravitreal aflibercept 2q8 and ranibizumab 0.5q4 treatment arms, the approved dosing for each agent worldwide. Change in composite NEI VFQ-25 score was evaluated based on categorical change in visual acuity (worsened, unchanged, improved). RESULTS: Baseline NEI VFQ-25 scores were similar for both treatments in both studies. Mean change from baseline to 52 weeks was similar for ranibizumab 0.5q4 and intravitreal aflibercept 2q8 across all 12 subscales, with the greatest improvements noted for mental health and general vision (9.0-11.6 points, both treatments, both studies). Improvement of 4 points or more (both treatments, both studies) also was observed for subscales near vision, distance vision, role difficulties, and dependency. Mean change from baseline to 52 weeks in NEI VFQ-25 composite score (pooled data) stratified by clinical response showed meaningful improvement only in patients who gained 5 Early Treatment Diabetic Retinopathy letters or more (7.3 and 7.8 points for intravitreal aflibercept 2q8 and ranibizumab 0.5q4, respectively). CONCLUSIONS: Visual function outcomes were similar across all NEI VFQ-25 subscales over 52 weeks for intravitreal aflibercept 2q8 and ranibizumab 0.5q4, with clinically meaningful improvement recorded in 6 of 12 subscales.

The PFA-AMeX method achieves a good balance between the morphology of tissues and the quality of RNA content in DNA microarray analysis with laser-capture microdissection samples.

Recently, large-scale gene expression profiling is often performed using RNA extracted from unfixed frozen or formalin-fixed paraffin embedded (FFPE) samples. However, both types of samples have drawbacks in terms of the morphological preservation and RNA quality. In the present study, we investigated 30 human prostate tissues using the PFA-AMeX method (fixation using paraformaldehyde (PFA) followed by embedding in paraffin by AMeX) with a DNA microarray combined with laser-capture microdissection. Morphologically, in contrast to the case of atypical adenomatous hyperplasia, loss of basal cells in prostate adenocarcinomas was as obvious in PFA-AMeX samples as in FFPE samples. As for quality, the loss of rRNA peaks 18S and 28S on the capillary electropherograms from both FFPE and PFA-AMeX samples showed that the RNA was degraded equally during processing. However, qRT-PCR with 3' and 5' primer sets designed against human beta-actin revealed that, although RNA degradation occurred in both methods, it occurred more mildly in the PFA-AMeX samples. In conclusion, the PFA-AMeX method is good with respect to morphology and RNA quality, which makes it a promising tool for DNA microarrays combined with laser-capture microdissection, and if the appropriate RNA quality criteria are used, the capture of credible GeneChip data is well over 80% efficient, at least in human prostate specimens.

Economics of malaria prevention in US travelers to West Africa.

BACKGROUND: Pretravel health consultations help international travelers manage travel-related illness risks through education, vaccination, and medication. This study evaluated costs and benefits of that portion of the health consultation associated with malaria prevention provided to US travelers bound for West Africa. METHODS: The estimated change in disease risk and associated costs and benefits resulting from traveler adherence to malaria chemoprophylaxis were calculated from 2 perspectives: the healthcare payer's and the traveler's. We used data from the Global TravEpiNet network of US travel clinics that collect de-identified pretravel data for international travelers. Disease risk and chemoprophylaxis effectiveness were estimated from published medical reports. Direct medical costs were obtained from the Nationwide Inpatient Sample and published literature. RESULTS: We analyzed 1029 records from January 2009 to January 2011. Assuming full adherence to chemoprophylaxis regimens, consultations saved healthcare payers a per-traveler average of $14 (9-day trip) to $372 (30-day trip). For travelers, consultations resulted in a range of net cost of $20 (9-day trip) to a net savings of $32 (30-day trip). Differences were mostly driven by risk of malaria in the destination country. CONCLUSIONS: Our model suggests that healthcare payers save money for short- and longer-term trips, and that travelers save money for longer trips when travelers adhere to malaria recommendations and prophylactic regimens in West Africa. This is a potential incentive to healthcare payers to offer consistent pretravel preventive care to travelers. This financial benefit complements the medical benefit of reducing the risk of malaria.

Absorption peak decomposition of an inhomogeneous nanoparticle ensemble of hexagonal tungsten bronzes using the reduced Mie scattering integration method.

Recent optical analyses of cesium-doped hexagonal tungsten bronze have accurately replicated the absorption peak and identified both plasmonic and polaronic absorptions in the near-infrared region, which have been exploited in various technological applications. However, the absorption peaks of tungsten oxides and bronzes have not generally been reproduced well, including those of the homologous potassium- and rubidium-doped hexagonal tungsten bronzes that lacked evidence of polaronic subpeaks. The present study reports a modified and simplified Mie scattering integration method which incorporates the ensemble inhomogeneity effect and allows precise peak decomposition and determination of the physical parameters of nanoparticles. The decomposed peaks were interpreted in terms of electronic structures, screening effect, and modified dielectric functions. The analysis revealed that the plasma frequencies, polaron energies, and the number of oxygen vacancies decrease in the dopant order Cs → Rb → K. The coexistence of plasmonic and polaronic excitations was confirmed for all the alkali-doped hexagonal tungsten bronzes.

Anti-Thy-1 Antibody-mediated Complement-dependent Cytotoxicity is Regulated by the Distribution of Antigen, Antibody and Membrane Complement Regulatory Proteins in Rats.

Some therapeutic antibodies as anticancer agents exert their effects through the host immune system, but the factors that predict their cytotoxicity, including complement-dependent cytotoxicity (CDC), are unclear. In the present study, we attempted to elucidate some of these factors in a preclinical model. CDC-related mesangiolysis caused by administration of the anti-Thy-1.1 antibody can be studied in the rat anti-Thy-1 glomerulonephritis model, so the model was used in this study. Three animals each were sacrificed at 0.5, 1, 8, 24 and 48 hours after i.v. administration of the anti-Thy-1.1 antibody at 1mg/kg. The distribution of the Thy-1.1 antigen and 2 membrane complement regulatory proteins (mCRPs), Crry and CD55, in three non-treated animals and the distribution of the injected antibody and C3 in the model was studied by immunohistochemistry. In the mesangial cells of the kidney, both expression of the antigen and distribution of the antibody with C3 deposition were observed with weak expression of mCRPs. There was also antigen and antibody distribution in the medullary cells of the adrenal gland and in the lymphocytes of the thymus but no C3 deposition, which was thought to be related to high expression of mCRPs. The antigen was observed in several other organs and tissues without distribution of the antibody. Cell death was only observed in the mesangial cells. These results clearly demonstrate that activation of CDC is regulated by several factors, such as distribution of the target molecule, antibody distribution and the balance among the molecules of the CDC cascade and mCRPs.

Expression of Membrane Complement Regulatory Proteins Crry and CD55 in Normal Rats.

Some anticancer therapeutic antibodies are designed to act through complement-dependent cytotoxicity (CDC). It has been reported that there are many membrane complement regulatory proteins (mCRPs) that inhibit CDC. In the present study, we examined the expression of two mCRPs, the complement receptor 1-related gene/protein Y (Crry) and the decay-accelerating factor CD55, in three normal rats by immunohistochemistry. Crry and CD55 were detected widely in rat organs and tissues. Crry was found mainly in the urinary, digestive, respiratory, immunohematopoietic, circulatory and neuroendocrine systems. CD55 was found in the urinary, digestive and neuroendocrine systems. However, the two molecules were expressed in separate cells within the same organ. These results suggest that the distribution of mCRPs is related to the strict regulation of CDC activation in these organs and tissues and that the two molecules have a nonoverlapping expression pattern, a fact indicating specific roles in CDC regulation.

Stimulation of adrenal chromaffin cell proliferation by hypercalcemia induced by intravenous infusion of calcium gluconate in rats.

Increased incidence of adrenal pheochromocytoma is frequently encountered in rat carcinogenicity studies. In some of the studies, the finding is judged to be due to a rat-specific mechanism of carcinogenesis caused by a disturbance of calcium homeostasis. However, direct evidence that the proliferation of chromaffin cells in the adrenal medulla is induced solely by hypercalcemia is not available. In this study, calcium gluconate was intravenously infused for 7 days to rat chromaffin cells by a tail cuff method, and cumulative labeling with bromodeoxyuridine (BrdU) was carried out to evaluate the proliferative activity. The serum calcium concentration was dose-dependently increased, and a high calcium concentration was stably sustained from day 2 to 7. In the adrenal medulla, BrdU-positive chromaffin cells increased in the calcium gluconate-treated animals, and the BrdU-labeling index increased in a dose-dependent manner. In addition, an increased BrdU-labeling index of chromaffin cells was shown to correlate with the serum calcium concentration. Our results demonstrate that hypercalcemia directly enhances the proliferative activity of chromaffin cells and that the proliferative activity is correlated with the serum calcium concentration.

Gastrointestinal endoscopic practice during COVID-19 pandemic: a multi-institutional survey.

Introduction. An on-going coronavirus disease 2019 (COVID-19) has become a challenge all over the world. Since an endoscopy unit and its staff are at potentially high risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, we conducted a survey for the management of the gastrointestinal endoscopic practice, personal protective equipment (PPE), and risk assessment for COVID-19 during the pandemic at multiple facilities.Methods. The 11-item survey questionnaire was sent to representative respondent of Department of Gastroenterology, Osaka City University Hospital, and its 19 related facilities.Results. A total of 18 facilities submitted valid responses and a total of 373 health care professionals (HCPs) participated. All facilities (18/18: 100%) were screening patients at risk for SARS-CoV-2 infection before endoscopy. During the pandemic, we found that the total volume of endoscopic procedures decreased by 44%. Eleven facilities (11/18: 61%) followed recommendations of the Japan Gastroenterological Endoscopy Society (JGES); consequently, about 35%-50% of esophagogastroduodenoscopy and colonoscopy were canceled. Mask (surgical mask or N95 mask), face shield/goggle, gloves (one or two sets), and gown (with long or short sleeves) were being used by endoscopists, nurses, endoscopy technicians, and endoscope cleaning staff in all the facilities (18/18: 100%). SARS-CoV-2 infection risk assessment of HCPs was conducted daily in all the facilities (18/18: 100%), resulting in no subsequent SARS-CoV-2 infection in HCPs.Conclusion. COVID-19 has had a dramatic impact on the gastrointestinal endoscopic practice. The recommendations of the JGES were appropriate as preventive measures for the SARSCoV-2 infection in the endoscopy unit and its staff.

Antibody to CD137 Activated by Extracellular Adenosine Triphosphate Is Tumor Selective and Broadly Effective In Vivo without Systemic Immune Activation.

Agonistic antibodies targeting CD137 have been clinically unsuccessful due to systemic toxicity. Because conferring tumor selectivity through tumor-associated antigen limits its clinical use to cancers that highly express such antigens, we exploited extracellular adenosine triphosphate (exATP), which is a hallmark of the tumor microenvironment and highly elevated in solid tumors, as a broadly tumor-selective switch. We generated a novel anti-CD137 switch antibody, STA551, which exerts agonistic activity only in the presence of exATP. STA551 demonstrated potent and broad antitumor efficacy against all mouse and human tumors tested and a wide therapeutic window without systemic immune activation in mice. STA551 was well tolerated even at 150 mg/kg/week in cynomolgus monkeys. These results provide a strong rationale for the clinical testing of STA551 against a broad variety of cancers regardless of antigen expression, and for the further application of this novel platform to other targets in cancer therapy. SIGNIFICANCE: Reported CD137 agonists suffer from either systemic toxicity or limited efficacy against antigen-specific cancers. STA551, an antibody designed to agonize CD137 only in the presence of extracellular ATP, inhibited tumor growth in a broad variety of cancer models without any systemic toxicity or dependence on antigen expression.See related commentary by Keenan and Fong, p. 20.This article is highlighted in the In This Issue feature, p. 1.

[A case of hepatocellular carcinoma with portal vein thrombus(Vp3)and lung metastases(stage IVB),which responded completely to treatment with Tegafur/Uracil].

A 65-year-old woman who had diffuse hepatocellular carcinoma(HCC)with tumor thrombus of right portalvein(Vp3) and lung metastases(Stage IVB)was treated by single-agent therapy with tegafur/uracil(UFT). As a result, primary and metastatic tumors were not recognized by diagnostic imaging, with a noted decrease of AFP, AFP-L3 and PIVKA-II. Generally, oral chemotherapy for HCC is not recommended because of the low response rate. However, there have been some reports including the present case which have showed a marked response with UFT. We thus conclude that UFT can be an option with low risk of crucial adverse effects in the treatment of selected HCC patients.

[A case of congenital esophageal stenosis that remained untreated until adulthood and was improved by endoscopic balloon dilatation].

A 20-year-old man had suffered from dysphagia since primary school. Upper gastrointestinal and endoscopy examinations revealed severe circumferential stenosis of the upper intra-thoracic esophagus. Secondary stenosis due to factors such as inflammation did not appear present, so congenital esophageal stenosis (CES) was diagnosed. Dysphagia improved after two endoscopic balloon dilatations. Almost all cases of CES are treated in baby-hood, and individuals who remain untreated until adulthood are rare. Check ups and diagnoses should be made taking CES into consideration, even in adults.

First-Principles Calculations of x-Dependent Ground Structures and Optical Properties of Ca x La1-x B6.

High transparency in the visible region is desired to manufacture solar control films and glasses for various applications. To improve the visible light transparency of LaB6 nanoparticles which exhibit strong absorption in the near-infrared region, the substitution of La with Ca is investigated using first-principles calculations. Among the numerous atomic replacement configurations in Ca x La1-x B6, all 762 structures existing in the supercells that are up to 8 times the primitive cell are comprehensively evaluated, and the most stable ground structures in Ca x La1-x B6 are deduced. The optical properties of the ground structures are derived by performing high-precision calculations using the HSE06 functional, which reveal that Ca x La1-x B6 with 0 < x < 1/4 is preferred as a solar shielding material with improved visible transparency. This method is effective for the investigation of the effect of substitutional elements in composite compounds on their physical properties.

Cesium polytungstates with blue-tint-tunable near-infrared absorption.

Revisiting Wöhler's method (1824), Cs-doped tungsten bronzes were synthesized by reducing Cs-polytungstate at high temperature, and were pulverized into nanoparticles for determining their optical properties. The high-temperature reduced Cs4W11O35 crystals absorbed strongly in the near-infrared, providing an improved luminous transparency with a less-bluish tint than normal Cs0.32WO3-y synthesized in a reductive atmosphere. The high-temperature reduction caused an orthorhombic-to-hexagonal phase transformation and a nonmetal-metal transition, which was monitored by spectrophotometry, X-ray diffraction, and X-ray photoelectron spectroscopy measurements, assisted by a first-principles analysis using a DFT+U method. The high-temperature reduction of Cs4W11O35 is concluded to decrease the number of W deficiencies and produce oxygen vacancies, releasing both free and trapped electrons into the conduction band and thereby activating the near-infrared absorption. The comparatively narrow bandgap of Cs4W11O35 was identified as the origin of the less-bluish tint of the produced Cs tungsten bronzes.

Segmentation of the Pathophysiological Stages of Diabetic Changes in the db/db Mouse.

The db/db mouse is one of the diabetes mellitus animal models and if the pathophysiological stages of diabetic changes in the mouse model could simulate the stages in human diabetes, the db/db mouse could be used to better evaluate drug candidates. Blood insulin, HbA1c levels and morphological features of pancreatic islets in db/db mice were evaluated to determine the pathophysiological stage. At 6 weeks of age, db/db mice showed the highest level of plasma insulin and lowest level of HbA1c, and histopathological examination revealed enlarged islets with a circular shape and hypertrophic islet cells. By 9 and 12 weeks of age, the plasma insulin levels had decreased to mid levels and HbA1c had increased to mid to high levels; histopathological examination at this time revealed two types of islets coexisting, enlarged circular islets and small irregular-shaped islets. By 15 and 22 weeks of age, plasma insulin had decreased further to low levels and HbA1c was at its highest level; the histopathological examination at this time revealed an increase in irregular-shaped and small islets. Based on blood insulin levels, HbA1c levels and histopathology findings in the db/db mice in this study, the clinical staging of diabetic changes were recognized. The pathophysiological stages of diabetes mellitus in this animal model were similar to the stages in humans.