Causes of death in Japanese patients with diabetes based on the results of a survey of 45,708 cases during 2001–2010: Report of the Committee on Causes of Death in Diabetes Mellitus

The principal causes of death among 45,708 patients with diabetes (29,801 men and 15,907 women) who died in 241 hospitals throughout Japan during 2001–2010 were determined based on a survey of the hospital records. Autopsy had been conducted in 978 of the 45,708 cases. The most frequent cause of death was malignant neoplasia (38.3%), followed by, in order of descending frequency: infections (17.0%); and then vascular diseases (14.9%), including renal failure (3.5%), ischemic heart diseases (4.8%) and cerebrovascular diseases (6.6%). Diabetic coma associated with hyperglycemia with or without ketoacidosis accounted for only 0.6% of the deaths. In regard to the relationship between the age and cause of death in patients with diabetes, the incidence of death due to vascular diseases was higher in patients over the age of 30 or 40 years, and the 97.0% of the total death due to vascular diseases was observed in patients over the age of 50 years. The incidence of death due to infectious diseases, especially pneumonia, increased in an age‐dependent fashion, and the 80.7% of the total death due to pneumonia was observed in patients over the age of 70 years. ’Poorer’ glycemic control was associated with the reduced lifespan of patients with diabetes, especially of those with nephropathy. The average age at death in the survey population was 72.6 years. The lifespan was 1.6 years shorter in patients with ‘poorer’ glycemic control than in those with ‘better’ glycemic control. In patients with diabetes of less than 10 years’ duration, the incidence of death due to macroangiopathy was higher than that due to nephropathy. Of the 45,708 patients with diabetes, 33.9% were on oral medication, 41.9% received insulin therapy and 18.8% were treated by diet alone. Among the patients in whom the cause of death was diabetic nephropathy, a high percentage, 53.7%, was on insulin therapy. The average age at death of the 45,708 patients with diabetes was 71.4 years in men and 75.1 years in women. However, the report of the Ministry of Health and Welfare of Japan in 2010 set the average lifespan of the Japanese at 79.6 years for men and 86.3 years for women. Thus, the average lifespan of patients with diabetes still appears to be shorter than that of the general population in Japan. However, the differences in lifespan between patients with diabetes and the general population were shorter than those in the former surveys.     

Xanthogranulomatous cholecystitis:Difficulty in differentiating from gallbladder cancer

AIM: To compare cases of xanthogranulomatous cholecystitis(XGC) and advanced gallbladder cancer and discuss the differential diagnoses and surgical options.METHODS: From April 2000 to December 2013, 6 XGC patients received extended surgical resections. During the same period, 16 patients were proven to have gallbladder(GB) cancer, according to extended surgical resection. Subjects chosen for analysis in this study were restricted to cases of XGC with indistinct borders with the liver as it is often difficult to distinguish these patients from those with advanced GB cancer. We compared the clinical features and computed tomography findings between XGC and advanced GB cancer. The following clinical features were retrospectively assessed: age, gender, symptoms, and tumor markers. As albumin and the neutrophil/lymphocyte ratio(NLR) are prognostic in several cancers, we compared serum albumin levels and the NLR between the two groups. The computerized tomography findings were used to compare the two diseases, determine the coexistence of gallstones, the pattern of GB thickening(focal or diffuse), the presence of a hypoattenuated intramural nodule, and continuity of the mucosal line.RESULTS: Based on the preoperative image findings, we suspected GB carcinoma in all cases includingXGC in this series. In addition, by pathological examination, we found that the group of patients with XGC developed inflammatory disease after surgery. Patients with XGC tended to have abdominal pain(4/6, 67%). However, there was no significant difference in clinical symptoms, including fever, between the two groups. Serum albumin and NLR were also similar in the two groups. Serum tumor markers, such as carcinoembryonic antigen(CEA) and carbohydrate antigen 19-9(CA19-9), tended to increase in patients with GB cancer. However, no significant differences in tumor markers were identified. On the other hand, gallstones were more frequently observed in patients with XGC(5/6, 83%) than in patients with GB cancer(4/16, 33%)(P = 0.0116). A hypoattenuated intramural nodule was found in 3 patients with XGC(3/6, 50%), but in only 1 patient with GB cancer(1/16, 6%)(P = 0.0024). The GB thickness, continuous mucosal line, and bile duct dilatation showed no significant differences between XGC and GB cancer.CONCLUSION: Although XGC is often difficult to differentiate from GB carcinoma, it is possible to obtain an accurate diagnosis by careful intraoperative gross observation, and several intraoperative frozen sections.     

An animal model of intrinsic dental erosion caused by gastro-oesophageal reflux disease

Objectives:  To explore the association between dental erosion and gastro-oesophageal reflux disease (GORD), we used an animal model of GORD.
Materials and Methods:  We performed an operation to force gastro-duodenal contents reflux in male Wistar rats, and examined the teeth in the reflux rats at 15 or 30 weeks postoperatively. Dental erosion was evaluated based on a slightly modified index from a previous report. Estimation of pH was employed in the oesophageal and gastric contents.
Results:  Macroscopically, dental erosion was only detected in the reflux rats. Histopathologically, dentin exposure was detected in three of the seven cases after 30 weeks. Alveolar bone destruction and osteomyelitis were also noted in severe cases. The pH of the oesophageal and stomach contents was 6.93 ± 0.15 and 3.7 ± 0.39, respectively.
Conclusions:  We confirmed the relationship between dental erosion and GORD. First step of dental erosion caused by GORD is the loss of surface enamel induced by regurgitation of an acidic liquid and acidic gas. Subsequently, further destruction of dental hard tissues and tooth supporting structure is accelerated by mixed juice with gastric and duodenal contents. The reflux animal model is a useful tool to examine the mechanism of dental erosion in GORD.     

The effects of stimulus rates on the amplitude of median nerve somatosensory evoked potentials: the developmental change

We examined the effects of stimulus rates on the somatosensory evoked potential (SEP) amplitudes following median nerve stimulation at the wrist in 42 children. We divided these subjects into five groups according to their age (0-6 months, 7-12 months, 1-3 years, 4-6 years and more than 7 years) and measured the peak-to-peak amplitude of every component (N9, P10, N11, P13/14, N18, N20, P23, N30) at stimulus rates of 1.0, 3.5 and 5.5 Hz. From N9 to N18, there was no significant change in amplitude nor latency with stimulus rate change in all groups. The amplitude attenuation was found at the N20 and N30 peaks in the young group (0 months to 3 years) and at P23 in all groups with an increasing stimulus rate. The attenuation rate of P23 amplitude was influenced by the age of subjects, being greater in younger groups and greatest in the youngest group (0-6 months). The differences of amplitude attenuation rate between this group and the rest were statistically significant. The results of this study indicate that the amplitudes of the cortical components of SEP in children are greatly influenced by the stimulus rate. Thus when we discuss the amplitude of cortical waves in childhood, we should also pay attention to the stimulus rates.     

Influence of CYP2C9 and vitamin k oxide reductase complex (VKORC)1 polymorphisms on time to determine the warfarin maintenance dose

Polymorphisms in cytochrome P450 (CYP) 2C9 and the vitamin K oxide reductase complex subunit 1 (VKORC1) greatly affect the maintenance dose of warfarin. To prevent adverse events, immediate dose adjustment is required. The purpose of this study was to investigate the influence of these polymorphisms on the time taken to determine the warfarin maintenance dose for individual patients, and to assess the advantages of genotype-based dosing on initial anticoagulant therapy. We analyzed the genotypes of CYP2C9 and VKORC1 from 72 patients. The number of days taken to determine the maintenance dose was compared with the genotypes. The time taken to determine the maintenance dose of warfarin in group A (CYP2C9*1/*1, VKORC1 -1639AA), B (*1/*1, - 1639GA), C (*1/*3, - 1639AA), and D (*1/*3, - 1639GA) patients was 19 +/- 19, 28 +/- 28, 27 +/- 20 and 7 days, respectively. We analyzed the relationship between the initial dose of warfarin and the number of days required to determine the maintenance dose based on the VKORC1 genotypes. Patients with the VKORC1 - 1639AA genotype and who were initially treated with more than 3mg warfarin, required approximately 2 weeks for the maintenance dose to be determined. Patients with the VKORC1 - 1639GA genotype and the same initial warfarin dosage required approximately a month; however, patients initially treated with 5 mg of warfarin only required 9.5 +/- 5.3 days. We found a tendency that the time taken to determine the warfarin maintenance dose depends on the genotypes. Genotype-based dosing may improve initial anticoagulant therapy.     

Activation of metabotropic glutamate 2/3 receptors attenuates methamphetamine-induced hyperlocomotion and increase in prefrontal serotonergic neurotransmission

Rationale

Metabotropic glutamate (mGlu) 2/3 receptor agonists inhibit amphetamine- and phencyclidine-induced hyperlocomotion. The mechanism for the antipsychotic effect of mGlu2/3 receptor agonists was studied in a hypoglutamatergic model, but not a hyperdopaminergic model.

Objectives

To study the mechanism for the antipsychotic effect of the agonist in the hyperdopaminergic model, this study examined the effects of the selective mGlu2/3 receptor agonist MGS0028 on methamphetamine-induced hyperlocomotion and the increases in extracellular levels of serotonin, dopamine, noradrenaline, and glutamate in the prefrontal cortex and nucleus accumbens of mice.

Results

Systemic administration of MGS0028 attenuated methamphetamine-induced hyperlocomotion in a dose-dependent manner. Microdialysis studies showed that MGS0028 significantly inhibited methamphetamine-induced increases in the extracellular serotonin, but not dopamine and noradrenaline, levels in the prefrontal cortex, and it did not affect methamphetamine-induced increases in the extracellular amine levels in the nucleus accumbens. Methamphetamine did not affect the glutamate release in the prefrontal cortex and nucleus accumbens. Local application of MGS0028 into the prefrontal cortex also attenuated methamphetamine-induced hyperlocomotion and increases in the extracellular serotonin levels in the prefrontal cortex. Moreover, MGS0028 did not affect methamphetamine-induced hyperlocomotion in the mice pretreated with p-chlorophenylalanine, a serotonin synthesis inhibitor.

Conclusions

Activation of prefrontal mGlu2/3 receptors inhibits the psychomotor stimulant effect of methamphetamine in mice, and the prefrontal serotonergic system may be involved in this effect. The finding provides evidence that prefrontal mGlu2/3 receptors are functionally coupled with the serotonergic system.     

MEK-ERK pathway modulation ameliorates disease phenotypes in a mouse model of Noonan syndrome associated with the Raf1(L613V) mutation

Hypertrophic cardiomyopathy (HCM) is a leading cause of sudden death in children and young adults. Abnormalities in several signaling pathways are implicated in the pathogenesis of HCM, but the role of the RAS-RAF-MEK-ERK MAPK pathway has been controversial. Noonan syndrome (NS) is one of several autosomal-dominant conditions known as RASopathies, which are caused by mutations in different components of this pathway. Germline mutations in RAF1 (which encodes the serine-threonine kinase RAF1) account for approximately 3%-5% of cases of NS. Unlike other NS alleles, RAF1 mutations that confer increased kinase activity are highly associated with HCM. To explore the pathogenesis of such mutations, we generated knockin mice expressing the NS-associated Raf1(L613V) mutation. Like NS patients, mice heterozygous for this mutation (referred to herein as L613V/+ mice) had short stature, craniofacial dysmorphia, and hematologic abnormalities. Valvuloseptal development was normal, but L613V/+ mice exhibited eccentric cardiac hypertrophy and aberrant cardiac fetal gene expression, and decompensated following pressure overload. Agonist-evoked MEK-ERK activation was enhanced in multiple cell types, and postnatal MEK inhibition normalized the growth, facial, and cardiac defects in L613V/+ mice. These data show that different NS genes have intrinsically distinct pathological effects, demonstrate that enhanced MEK-ERK activity is critical for causing HCM and other RAF1-mutant NS phenotypes, and suggest a mutation-specific approach to the treatment of RASopathies.     

IGSF4 is a novel TCR ζ-chain-interacting protein that enhances TCR-mediated signaling

Immunoglobulin superfamily member 4 (IGSF4) is a known ligand of CRTAM, a receptor expressed in activated NKT and CD8(+) T cells, but its function in T cell immunity has not been elucidated. In this study, we show that IGSF4 directly interacts with the T cell receptor (TCR) ζ-chain and enhances TCR signaling by enhancing ζ-chain phosphorylation. Ectopic overexpression of IGSF4 enhances TCR-mediated T cell activation. In contrast, IGSF4 knockdown shows a dramatic decrease in markers associated with T cell activation compared with those in control small interfering RNA. The transmembrane domain is essential for TCR ζ-chain association and clustering to the immunological synapse, and the ectodomain is associated with T cell interaction with antigen-presenting cells (APCs). IGSF4-deficient mice have impaired TCR-mediated thymocyte selection and maturation. Furthermore, these mice reveal attenuated effector T cell functions accompanied by defective TCR signaling. Collectively, the results indicate that IGSF4 plays a central role in T cell functioning by dual independent mechanisms, control of TCR signaling and control of T cell-APC interaction.     

Identification of a novel TPM1 mutation in a family with left ventricular noncompaction and sudden death

Left ventricular noncompaction (LVNC) is a cardiomyopathy morphologically characterized by 2-layered myocardium, numerous prominent trabeculations, and deep intertrabecular recesses communicating with the left ventricular cavity. The purpose of this study was to investigate patients with LVNC for possible disease causing mutations. We screened 4 genes (TAZ, LDB3, DTNA and TPM1) in 51 patients with LVNC for mutations by polymerase chain reaction and direct DNA sequencing. A novel missense substitution in exon 1 of TPM1 (c.109A>G: p.Lys37Glu) was identified in three affected members of a family with isolated LVNC. The substitution brings about a change in amino acid charge at a highly conserved residue and could result in aberrant mRNA splicing. This variant was not identified in 200 normal control samples. Pathologic analysis of a right ventricular myocardial specimen from the proband's maternal aunt revealed endocardial and subendocardial fibrosis with prominent elastin deposition, as well as the presence of adipose tissue between muscle layers, pathologic changes that are distinct from those seen in patients with HCM or DCM. Screening of the proband and her mother for variants in other sarcomeric protein-encoding candidate genes, MYH7, MYBPC3, TNNT2, TNNI3, ACTC, MYL2, and MYL3, did not identify any other non-synonymous variants or variants in splice donor-acceptor sequences that were potentially disease causing. We conclude TPM1 is a potential candidate disease-causing gene for isolated LVNC, especially in patients experiencing sudden death.