Safety of tapering tacrolimus dose in patients with well-controlled anti-acetylcholine receptor antibody-positive myasthenia gravis

BACKGROUND AND PURPOSE

Tapering immunosuppressants is desirable in patients with well-controlled myasthenia gravis (MG). However, the association between tapering of calcineurin inhibitor dosage and reduction-associated exacerbation is not known. The aim of this study was to clarify the frequency of reduction-associated exacerbation when tacrolimus is tapered in stable patients with anti-acetylcholine receptor antibody-positive MG, and to determine the factors that predict exacerbations.

METHODS

We retrospectively analyzed 115 patients in whom tacrolimus dosage was tapered. The reduction-associated exacerbation was defined as the appearance or worsening of one or more MG symptoms <3 months after the reduction.

RESULTS

Tacrolimus dosage was successfully tapered in 110 patients (96%) without any exacerbation. Five patients (4%) experienced an exacerbation, but symptoms were reversed in all patients when the tacrolimus dose was increased to the previous maintenance level. No patient developed an MG crisis. The age at onset was significantly earlier (30 vs. 56 years, P = 0.025) and the reduction in dosage was significantly larger (2.0 vs. 1.0 mg/day, P = 0.002) in patients with reduction-associated exacerbation than in those without exacerbation. The cut-off values determined in a receiver-operating characteristic curve analysis were 52 years (sensitivity, 57%; specificity, 100%) for the age at onset and 1.5 mg (sensitivity, 80%; specificity, 100%) for the dose reduction.

CONCLUSION

Tapering of tacrolimus was possible in most patients with well-controlled anti-acetylcholine receptor antibody-positive MG. Early age at onset and a large reduction from maintenance dosage were associated with exacerbation. Reductions ≤1.5 mg/day from the maintenance dosage should be considered for patients with late-onset disease.

Down-regulation of glutamate release from hippocampal neurons by sialidase

Sialidase, which removes sialic acid residues in sialylglycoconjugates, is essential for hippocampal memory and synaptic plasticity. Enzyme activity of sialidase is rapidly increased in response to neural excitation. Because sialic acid bound to gangliosides such as the tetra-sialoganglioside GQ1b is crucial for calcium signalling and neurotransmitter release, neural activity-dependent removal of sialic acid may affect hippocampal neurotransmission. In the present study, we found that 2-deoxy-2, 3-didehydro-D-N-acetylneuraminic acid (DANA), a sialidase inhibitor, increased expression of ganglioside GQ1b/GT1a in hippocampal acute slices. Extracellular glutamate level in the rat hippocampus measured by using in vivo microdialysis was increased by the sialidase inhibitor 2, 3-dehydro-2-deoxy-N-glycolylneuraminic acid as well as DANA. Synaptic vesicle exocytosis and intracellular Ca2+ increase evoked by high-K+ were also enhanced by DANA in primary cultured hippocampal neurons. Expression of GQ1b/GT1a was rapidly decreased by depolarization with high-K+, suggesting that the increase in sialidase activity by neural excitation is sufficient for cleavage of sialic acid. Our findings indicate that sialidase down-regulates glutamate release from hippocampal neurons via Ca2+ signalling modulation. Neural activity-dependent desialylation by sialidase may be a negative-feedback factor against presynaptic activity.

Weaning stage hyperglycemia induces glucose-insensitivity in arcuate POMC neurons and hyperphagia in type 2 diabetic GK rats

Hyperphagia triggers and accelerates diabetes, and prevents proper dietary control of glycemia. Inversely, the impact of hyperglycemia on hyperphagia and possible mechanistic cause common for these two metabolic disorders in type 2 diabetes are less defined. The present study examined the precise developmental process of hyperglycemia and hyperphagia and explored the alterations in the hypothalamic arcuate nucleus (ARC), the primary feeding and metabolic center, in Goto-Kakizaki (GK) rats with type 2 diabetes and nearly normal body weight. At mid 3 to 4 weeks of age, GK rats first exhibited hyperglycemia, and then hyperphagia and reduced mRNA expressions for anorexigenic pro-opiomelanocortin (POMC) and glucokinase in ARC. Furthermore, [Ca²⁺]i responses to high glucose in ARC POMC neurons were impaired in GK rats at 4 weeks. Treating GK rats from early 3 to mid 6 weeks of age with an anti-diabetic medicine miglitol not only suppressed hyperglycemia but ameliorated hyperphagia and restored POMC mRNA expression in ARC. These results suggest that the early hyperglycemia occurring in weaning period may lead to impaired glucose sensing and neuronal activity of POMC neurons, and thereby induce hyperphagia in GK rats. Correction of hyperglycemia in the early period may prevent and/or ameliorate the progression of hyperphagia in type 2 diabetes.

Long-range Correlated Glucose Fluctuations in Diabetes

Objectives : Our objective is to investigate diabetes- related alteration of glucose control in diurnal fluctuations in normal daily life by detrended fluctuation analysis (DFA).

Methods : The fluctuations of glucose of 12 non-diabetic subjects and 15 diabetic patients were measured using a continuous glucose monitoring system (CGMS) over a period of one day. The glucose data was calculated by the DFA method, which is capable of revealing the presence of long-range correlations in time series with inherent non-stationarity.

Results : Compared with the non-diabetic subjects, the mean glucose level and the standard deviation are significantly higher in the diabetic group.

The DFA exponent α is calculated, and glucose time series are searched for the presence of negatively (0.5 < α <1.5) or positively (1.5 < α) correlated fluctuations. A crossover phenomenon, i.e. a change in the level of correlations, is observed in the non-diabetic subjects at about two hours; the net effects of glucose flux/reflux causing temporal changes in glucose concentration are negatively correlated in a “long-range" (> two hours) regime. However, for diabetic patients, the DFA exponent α = 1.65 ± 0.30, and in the same regime positively correlated fluctuations are observed, suggesting that the net effects of the flux and reflux persist for many hours.

Conclusions : Such long-range positive correlation in glucose homeostasis may reflect pathogenic mechanisms of diabetes, i.e., the lack of the tight control in blood glucose regulation. Using modern time series analysis methods such as DFA, continuous evaluation of glucose dynamics could promote better diagnoses and prognoses of diabetes and a better understanding of the fundamental mechanism of glucose dysregulation in diabetes.

Strong polarization switching with low-energy loss in hydrogen-bonded organic antiferroelectrics

The electric-field-induced phase transition from antipolar to polar structures is at the heart of antiferroelectricity. We demonstrate direct evidence of antiferroelectricity by applying a strong electric field to two antipolar crystals of squaric acid (SQA) and 5,5'-dimethyl-2,2'-bipyridinium chloranilate. The field-induced polarization of SQA is quite large and reasonably explained by the theoretically calculated polarization on the hydrogen-bonded sheet sublattice. The pseudo-tetragonal lattice of SQA permits unique switching topologies that produce two different ferroelectric phases of low and high polarizations. By tilting the applied field direction, the electrical switching mechanism can be attributed to a 90° rotation of the sheet polarization. From the viewpoint of applications, the strong polarization, high switching field, and quite slim hysteresis observed in the polarization versus electric field curve for SQA are advantageous for excellent-efficiency energy storage devices.

Severe hypoglycaemia is a major predictor of incident diabetic retinopathy in Japanese patients with type 2 diabetes

AIM

Hypoglycaemia is a common complication in diabetes patients. However, its relationship with retinopathy has not been well documented in patients with type 2 diabetes (T2D). This study aimed to investigate the associations between hypoglycaemia and the incidence and progression of diabetic retinopathy (DR).

METHODS

In this longitudinal cohort study, which was part of the Japan Diabetes Complications Study (JDCS), adult patients with T2D were recruited at 59 diabetes clinics across Japan. Their history of hypoglycaemia was assessed by standardized self-reported questionnaires. Severe hypoglycaemia was defined as having at least one episode with coma requiring an outpatients visit or hospitalization. Adjusted hazard ratios (HRs) for incidence and progression of DR over 8 years of follow-up were determined.

RESULTS

Of 1221 patients without DR, 127 (10.4%) had experienced non-severe hypoglycaemia within the previous year, whereas 10 (0.8%) reported severe hypoglycaemia episodes. During the 8-year follow-up involving 8492 person-years, 329 patients developed DR. In 410 patients with prevalent DR, the adjusted HRs for incident DR were 4.35 (95% CI: 1.98-9.56; P<0.01) and, for progression of DR, 2.29 (95% CI: 0.45-11.78; P=0.32) with severe hypoglycaemia.

CONCLUSION

Having a history of severe hypoglycaemia was one of the strongest predictors of incident DR in patients with T2D, with a fourfold increased risk. Identifying patients with greater risks of DR based on their history of hypoglycaemia may help to personalize risk evaluation in patients with diabetes.

Rapid regulation of sialidase activity in response to neural activity and sialic acid removal during memory processing in rat hippocampus

Sialidase cleaves sialic acids on the extracellular cell surface as well as inside the cell and is necessary for normal long-term potentiation (LTP) at mossy fiber-CA3 pyramidal cell synapses and for hippocampus-dependent spatial memory. Here, we investigated in detail the role of sialidase in memory processing. Sialidase activity measured with 4-methylumbelliferyl-α-d-N-acetylneuraminic acid (4MU-Neu5Ac) or 5-bromo-4-chloroindol-3-yl-α-d-N-acetylneuraminic acid (X-Neu5Ac) and Fast Red Violet LB was increased by high-K⁺-induced membrane depolarization. Sialidase activity was also increased by chemical LTP induction with forskolin and activation of BDNF signaling, non-NMDA receptors, or NMDA receptors. The increase in sialidase activity with neural excitation appears to be caused not by secreted sialidase or by an increase in sialidase expression but by a change in the subcellular localization of sialidase. Astrocytes as well as neurons are also involved in the neural activity-dependent increase in sialidase activity. Sialidase activity visualized with a benzothiazolylphenol-based sialic acid derivative (BTP3-Neu5Ac), a highly sensitive histochemical imaging probe for sialidase activity, at the CA3 stratum lucidum of rat acute hippocampal slices was immediately increased in response to LTP-inducible high-frequency stimulation on a time scale of seconds. To obtain direct evidence for sialic acid removal on the extracellular cell surface during neural excitation, the extracellular free sialic acid level in the hippocampus was monitored using in vivo microdialysis. The free sialic acid level was increased by high-K⁺-induced membrane depolarization. Desialylation also occurred during hippocampus-dependent memory formation in a contextual fear-conditioning paradigm. Our results show that neural activity-dependent desialylation by sialidase may be involved in hippocampal memory processing.

Prognostic significance of preoperative inflammatory response biomarkers in patients undergoing curative thoracoscopic esophagectomy for esophageal squamous cell carcinoma

BACKGROUND

Recent studies have revealed significant relationships between the lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) and survival in various cancers. The purpose of this study was to confirm whether the LMR, NLR, and PLR have prognostic values, independent of clinicopathological criteria, in patients undergoing curative resection for esophageal cancer.

METHODS

The LMR, NLR and PLR were calculated in 147 consecutive patients who underwent curative esophagectomy between January 2006 and December 2014. Receiver operating characteristics (ROC) curve analysis was conducted to identify the optimal cutoff values of each biomarkers.

RESULTS

In multivariate analysis for cancer-specific survival (CSS), pTNM stage (p < 0.0001) and low LMR (p = 0.0081) were selected as independent prognostic factor. Similarly, pTNM stage(p < 0.0001) and low LMR (p = 0.0225) were found to be independent prognostic factor for overall survival (OS). There was no significant relationship between LMR, NLR and PLR and survival in patients with stage I or II, however, significant relationships between LMR and CSS or OS were observed in patients with stage III esophageal cancer.

CONCLUSIONS

LMR can be used as a novel predictor of postoperative CSS and OS in patients with esophageal cancer and that it may be useful in identifying patients with a poor prognosis even after radical esophagectomy.

Significance of Development and Reversion of Collaterals on MRI in Early Neurologic Improvement and Long-Term Functional Outcome after Intravenous Thrombolysis for Ischemic Stroke

BACKGROUND AND PURPOSE

Predicting response to rtPA is essential in the era of endovascular therapy for stroke. The purpose of this study was to elucidate prognostic factors of early neurologic improvement and long-term outcome with respect to the development and reversion of leptomeningeal collaterals in recanalization therapy after acute ischemic stroke.

MATERIALS AND METHODS

We analyzed consecutive patients with proximal MCA occlusion treated with rtPA from 2007 to 2012 at 2 hospital stroke centers. All patients routinely underwent brain MR imaging before rtPA. To assess the reversion of collateral signs, we included patients who underwent follow-up MR imaging. We assessed the development and reversion of collaterals by using a combination of 2 MR imaging collateral markers, the hyperintense vessel sign and the posterior cerebral artery laterality sign. Early neurologic improvement was defined as a decrease in the NIHSS score of ≥10 or a score of ≤2 at 24 hours of treatment.

RESULTS

Early neurologic improvement was observed in 22 of 48 eligible patients. The development of collaterals at arrival (15/22 versus 9/26, P = .042) was significantly associated with early neurologic improvement. Multivariate analysis adjusting for other variables showed that the development of collaterals at arrival (OR, 4.82; 95% CI, 1.34-19.98; P = .015) was independently associated with early neurologic improvement. Reversion of collaterals was significantly associated with successful recanalization (P < .001), and multivariate analysis showed that the reversion of collaterals was an independent prognostic factor of long-term functional outcome (OR, 5.07; 95% CI, 1.38-22.09; P = .013).

CONCLUSIONS

Our results indicate that the development of leptomeningeal collaterals plays a crucial role in achieving early neurologic improvement, and reversion of collaterals predicts a favorable outcome via arterial recanalization after rtPA treatment for acute stroke.

Spinal cord ring enhancement in patients with neuromyelitis optica

OBJECTIVES

Clinical and pathological significance of gadolinium (Gd)-enhancing pattern on magnetic resonance imaging (MRI), including ring enhancement (RE), is well documented in multiple sclerosis but not in neuromyelitis optica (NMO), especially in the spinal cord. The purpose of this study is to examine the prevalence of spinal cord RE in NMO and to determine the association between clinical characteristics and spinal cord RE.

MATERIALS AND METHODS

We retrospectively examined Gd-enhanced spinal cord MRI scans, during the acute phase, in patients with anti-aquaporin 4-positive NMO, including NMO spectrum disorder. We then analysed their clinical features and MRI imaging characteristics of spinal cord lesions.

RESULTS

Of the 30 patients with NMO, we enrolled 12 patients with 16 Gd-enhanced spinal cord MRI scans in this study. Five scans revealed RE (31.2%). Male ratio, as well as myelin basic protein (MBP) levels, in the cerebrospinal fluid (CSF) of patients with RE was significantly higher than those of patients without RE (P = 0.018, P = 0.026, respectively).

CONCLUSIONS

Spinal cord RE is common in patients with NMO. Higher MBP levels in the CSF of patients with RE can be associated with a higher degree of myelin damage.

Successful pregnancy outcomes in a patient with type A insulin resistance syndrome

BACKGROUND

The management of severe insulin resistance during pregnancy is challenging because of the increased risk of perinatal complications for both mother and fetus. We describe two consecutive pregnancies in a patient with severe insulin resistance caused by a mutation in the β subunit of the insulin receptor.

CASE REPORT

A non-obese Japanese woman was diagnosed as having diabetes mellitus during her first pregnancy at age 31 years. She presented at 6 weeks' gestation with a fasting plasma glucose concentration of 15.1 mmol/l and an HbA(1c) level of 95 mmol/mol (10.8%). Fasting insulin concentration was high at 68.8 μU/ml, suggesting severe insulin resistance. Anti-insulin and insulin-receptor antibodies were both negative. Genetic analysis revealed an in-frame heterozygous deletion mutation (∆Leu(999)) in the insulin receptor gene. Despite large daily doses (up to 480 units per day) of insulin aspart and isophane, the patient's postprandial plasma glucose level exceeded 11.1 mmol/l. In the patient's second pregnancy, the addition of metformin at a dose of 2250 mg per day achieved tighter glycaemic control, with lower doses of insulin lispro and isophane (up to 174 units/day). Both newborns, who were found to carry the same mutation, were small for gestational age and developed transient hypoglycaemia after birth.

CONCLUSION

Adding metformin to the conventional insulin regimen effectively achieved tight glycaemic control with a lower dose of insulin. The mutation of the insulin receptor gene might underlie the intrauterine growth retardation of the newborns. To our knowledge, this is the first report of successful management of diabetes mellitus in a pregnant woman with type A insulin resistance syndrome.

Highly sensitive nanoscale spin-torque diode

Highly sensitive microwave devices that are operational at room temperature are important for high-speed multiplex telecommunications. Quantum devices such as superconducting bolometers possess high performance but work only at low temperature. On the other hand, semiconductor devices, although enabling high-speed operation at room temperature, have poor signal-to-noise ratios. In this regard, the demonstration of a diode based on spin-torque-induced ferromagnetic resonance between nanomagnets represented a promising development, even though the rectification output was too small for applications (1.4 mV mW(-1)). Here we show that by applying d.c. bias currents to nanomagnets while precisely controlling their magnetization-potential profiles, a much greater radiofrequency detection sensitivity of 12,000 mV mW(-1) is achievable at room temperature, exceeding that of semiconductor diode detectors (3,800 mV mW(-1)). Theoretical analysis reveals essential roles for nonlinear ferromagnetic resonance, which enhances the signal-to-noise ratio even at room temperature as the size of the magnets decreases.

Catalytic preference of Salmonella typhimurium LT2 sialidase for N-acetylneuraminic acid residues over N-glycolylneuraminic acid residues

In a comparison of sialidase activities toward N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc), we found that Salmonella typhimurium LT2 sialidase (STSA) hardly cleaved 4-methylumbelliferyl Neu5Gc (4MU-Neu5Gc). The k cat/K m value of STSA for 4MU-Neu5Gc was found to be 110 times lower than that for 4-methylumbelliferyl Neu5Ac (4MU-Neu5Ac). Additionally, STSA had remarkably weak ability to cleave α2-3-linked-Neu5Gc contained in gangliosides and equine erythrocytes. In silico analysis based on first-principle calculations with transition-state analogues suggested that the binding affinity of Neu5Gc2en is 14.3 kcal/mol more unstable than that of Neu5Ac2en. The results indicated that STSA preferentially cleaves Neu5Ac residues rather than Neu5Gc residues, which is important for anyone using this enzyme to cleave α2-3-linked sialic acids.

Leisure-time physical activity is a significant predictor of stroke and total mortality in Japanese patients with type 2 diabetes: analysis from the Japan Diabetes Complications Study (JDCS)

AIMS/HYPOTHESIS

Our aim was to clarify the association between leisure-time physical activity (LTPA) and cardiovascular events and total mortality in a nationwide cohort of Japanese diabetic patients.

METHODS

Eligible patients (1,702) with type 2 diabetes (mean age, 58.5 years; 47% women) from 59 institutes were followed for a median of 8.05 years. A comprehensive lifestyle survey including LTPA and occupation was performed using standardised questionnaires. Outcome was occurrence of coronary heart disease (CHD), stroke and total mortality. The adjusted HR and 95% CI were calculated by Cox regression analysis.

RESULTS

A significant reduction in HR in patients in the top (≥ 15.4 metabolic equivalents [MET] h/week) vs the bottom tertile (≤ 3.7 MET h/week) of LTPA, adjusted by age, sex and diabetes duration, was observed in stroke (HR 0.55, 95% CI 0.32, 0.94) and total mortality (HR 0.49, 95% CI 0.26, 0.91) but not in CHD (HR 0.77, 95% CI 0.48, 1.25). The HR for stroke became borderline significant or nonsignificant after adjustment for lifestyle or clinical variables including diet or serum lipids. The significantly reduced total mortality by LTPA was independent of these variables and seemed not to be, at least mainly, attributed to reduced cardiovascular disease.

CONCLUSIONS/INTERPRETATION

In Japanese persons with type 2 diabetes, LTPA of 15.4 MET h/week or more was associated with a significantly lower risk of stroke partly through ameliorating combinations of cardiovascular risk factors. It was also associated with significantly reduced total mortality but independently of cardiovascular risk factors or events. These findings, implying differences from Western diabetic populations, should be considered in the clinical management of East Asians with diabetes.

Imbalance of Clara cell-mediated homeostatic inflammation is involved in lung metastasis

We have previously shown that tumor necrosis factor (TNF)α produced from primary tumor-induced expression of two endogenous Toll-like receptor 4 (TLR4) ligands, S100A8 and serum amyloid A3 (SAA3), in pre-metastatic lungs. However, mechanistic details of the signaling network and relevance to pulmonary physiology are poorly understood. Here, we identify Clara cells as a control tower of the network. Clara cell ablation by naphthalene suppressed pulmonary recruitment of CD11b+TLR4+ cells and spontaneous lung metastasis. Clara cells turned out to express TLR4 through which SAA3 was auto-amplified. Reciprocal bone marrow transplantation between wild-type and TLR4 knockout mice demonstrated that pulmonary TLR4+ Clara cells could be derived from bone marrow. SAA3-induced TNFα expression in both alveolar type II cells and macrophages. Primary co-cultures of alveolar type II cells and Clara cells revealed that the induction of TNFα in alveolar type II cells was dependent on the Clara cell-mediated amplification of SAA3. SAA3 induction by bacterial endotoxin also required both Clara cells and TLR4. Thus, pulmonary metastatic soil may feature deregulation of homeostatic inflammatory responses to constant assaults of microbes with endotoxin.

Long-term lifestyle intervention lowers the incidence of stroke in Japanese patients with type 2 diabetes: a nationwide multicentre randomised controlled trial (the Japan Diabetes Complications Study)

AIMS/HYPOTHESIS

The aim of the study was to clarify whether a therapeutic intervention focused on lifestyle modification affected the incidence of vascular complications in patients with established diabetes.

METHODS

A total of 2,033 eligible Japanese men and women aged 40-70 years with type 2 diabetes from 59 institutes were randomised to a conventional treatment group (CON), which continued to receive the usual care, and a lifestyle intervention group (INT), which received education on lifestyle modification regarding dietary habits, physical activities and adherence to treatment by telephone counselling and at each outpatient clinic visit, in addition to the usual care. Randomisation and open-label allocation were done by a central computer system. Primary analysis regarding measurements of control status and occurrence of macro- and microvascular complications was based on 1,304 participants followed for an 8 year period.

RESULTS

Although status of control of most classic cardiovascular risk factors, including body weight, glycaemia, serum lipids and BP, did not differ between groups during the study period, the incidence of stroke in the INT group (5.48/1,000 patient-years) was significantly lower than in the CON group (9.52/1,000 patient-years) by Kaplan- Meier analysis (p=0.02 by logrank test) and by multivariate Cox analysis (HR 0.62, 95% CI 0.39-0.98, p=0.04). The incidence of CHD, retinopathy and nephropathy did not differ significantly between groups. Lipoprotein(a) was another significant independent risk factor for stroke.

CONCLUSIONS/INTERPRETATION

These findings suggest that lifestyle modification had limited effects on most typical control variables, but did have a significant effect on stroke incidence in patients with established type 2 diabetes.

CLINICAL TRIAL REGISTRATION

UMIN-CTR C000000222

FUNDING

The Ministry of Health, Labour and Welfare, Japan

Large scale replication analysis of loci associated with lipid concentrations in a Japanese population

BACKGROUND

Recent genome wide association studies discovered seven novel loci that influence plasma concentrations of triglycerides, high density lipoprotein (HDL) and low density lipoprotein (LDL) cholesterol in Europeans. To date, large scale replication studies using populations with known differences in genome-wide linkage disequilibrium (LD) pattern have not been undertaken.

METHODS

To address this issue, we tested associations between single nucleotide polymorphisms (SNPs) within the seven novel loci and plasma lipid profiles in 21 010 Japanese individuals.

RESULTS

Multiple linear regression analyses showed that the rs3812316 in MLXIPL was strongly associated with triglyceride concentrations (p approximately 3.0x10(-11), 7.1 mg/dl decrease per minor C allele) and that rs599839 in CELSR2/PSRC1/SORT1 was strongly associated with LDL cholesterol concentrations (p approximately 3.1x10(-11), 4.7 mg/dl decrease per minor G allele) in the Japanese population. SNPs near ANGPTL3, TRIB1 and GALNT2 showed evidence for associations with triglyceride concentrations (3.6x10(-6)<p<5.1x10(-5)). SNP near TRIB1 showed association with LDL cholesterol concentrations (p approximately 1.2x10(-5)). On the other hand, SNPs in NCAN/CILP2/PBX4 and MVK/MMAB were not associated with any plasma lipid profiles in the Japanese population. Ethnic differences in LD pattern would explain the lack of association between these two loci and plasma lipid concentrations in the Japanese population.

CONCLUSION

Associations between the novel loci and plasma lipid concentrations were generally conserved in the Japanese population, with the exception of NCAN/CILP2/PBX4 and MVK/MMAB.

Search for a light pseudoscalar particle in the decay K_{L};{0}-->pi;{0}pi;{0}X

We performed a search for a light pseudoscalar particle X in the decay K_{L};{0}-->pi;{0}pi;{0}X, X-->gammagamma with the E391a detector at KEK. Such a particle with a mass of 214.3 MeV/c;{2} was suggested by the HyperCP experiment. We found no evidence for X and set an upper limit on the product branching ratio for K_{L};{0}-->pi;{0}pi;{0}X, X-->gammagamma of 2.4x10;{-7} at the 90% confidence level. Upper limits on the branching ratios in the mass region of X from 194.3 to 219.3 MeV/c;{2} are also presented.

Influence of IOP measurement through the wrong eyepiece of the slit lamp on Goldmann applanation tonometry

PURPOSE

This study examined whether intraocular pressure (IOP) measurements through the wrong eyepiece of the slit lamp may be a source of error.

METHODS

Seven skilled observers measured the IOP from seven healthy subjects. The observers used a Haag-Streit Goldmann applanation tonometer with two types of slit lamps (Haag-Streit and Rodenstock). In the Haag-Streit slit lamp the prism of the tonometer is aligned with the right part of the slit lamp optics. Conversely, in the Rodenstock slit lamp, the prism is aligned with the left. Each observer measured the IOP of each subject through the right eyepiece, through the left eyepiece, and under binocular vision.

RESULTS

The IOP measured with the left eyepiece of the Haag-Streit slit lamp was significantly higher than that measured with the right eyepiece and binocular vision. The IOP measured with the right eyepiece of the Rodenstock slit lamp was significantly higher than that measured with the left eyepiece and binocular vision.

CONCLUSIONS

IOP measurement through the wrong eyepiece of the slit lamp may be a source of error.

Metformin, but not pioglitazone, decreases postchallenge plasma ghrelin levels in type 2 diabetic patients: a possible role in weight stability?

AIM

Effects of metformin and pioglitazone on body weight are clearly different. Recently, the role of ghrelin, an orexigenic peptide derived from stomach, has been appreciated. Plasma ghrelin levels display a preprandial peak and postprandial suppression, suggesting its physiological role. We hypothesized that metformin or pioglitazone may modulate circulating ghrelin levels and this modulation may be related to differential effects on body weight with these agents.

METHODS

Thirty-five Japanese type 2 diabetic patients [21 men and 14 women, age 62 +/- 2 years, body mass index (BMI) 26.6 +/- 0.5 kg/m(2) and haemoglobin A1c (HbA1c) 8.2 +/- 0.1%, mean +/- s.e.] were randomly assigned to groups for the addition of metformin or pioglitazone. At baseline and 4 months later, a 75-g oral glucose tolerance test (OGTT) was performed to measure plasma ghrelin levels.

RESULTS

In 33 subjects who completed the study, the overall decrease in HbA1c ( approximately 1%) was comparable between the two groups. As expected, BMI increased in the pioglitazone group but not in the metformin group. After the treatment, plasma ghrelin levels at each point of OGTT remained unchanged in the pioglitazone group. In the metformin group, fasting ghrelin levels were unaltered, whereas the absolute levels at 30, 60 and 120 min decreased significantly. The area under the curve for the 2-h ghrelin profile also decreased significantly.

CONCLUSIONS

Metformin, but not pioglitazone, decreased plasma ghrelin levels after the glucose load. This decrease may in part account for weight stability in type 2 diabetic patients treated with metformin.

Search for the Decay K L0-->pi0nu nu[over]

We performed a search for the K L0-->pi0nu nu[over] decay at the KEK 12-GeV proton synchrotron. No candidate events were observed. An upper limit on the branching ratio for the decay was set to be 6.7 x 10(-8) at the 90% confidence level.

Long-range correlated glucose fluctuations in diabetes

OBJECTIVES

Our objective is to investigate diabetes-related alteration of glucose control in diurnal fluctuations in normal daily life by detrended fluctuation analysis (DFA).

METHODS

The fluctuations of glucose of 12 non-diabetic subjects and 15 diabetic patients were measured using a continuous glucose monitoring system (CGMS) over a period of one day. The glucose data was calculated by the DFA method, which is capable of revealing the presence of long-range correlations in time series with inherent non-stationarity.

RESULTS

Compared with the non-diabetic subjects, the mean glucose level and the standard deviation are significantly higher in the diabetic group. The DFA exponent alpha is calculated, and glucose time series are searched for the presence of negatively (0.5 < alpha < 1.5) or positively (1.5 < alpha) correlated fluctuations. A crossover phenomenon, i.e. a change in the level of correlations, is observed in the non-diabetic subjects at about two hours; the net effects of glucose flux/reflux causing temporal changes in glucose concentration are negatively correlated in a "long-range" (> two hours) regime. However, for diabetic patients, the DFA exponent alpha = 1.65 +/- 0.30, and in the same regime positively correlated fluctuations are observed, suggesting that the net effects of the flux and reflux persist for many hours.

CONCLUSIONS

Such long-range positive correlation in glucose homeostasis may reflect pathogenic mechanisms of diabetes, i.e., the lack of the tight control in blood glucose regulation. Using modern time series analysis methods such as DFA, continuous evaluation of glucose dynamics could promote better diagnoses and prognoses of diabetes and a better understanding of the fundamental mechanism of glucose dysregulation in diabetes.

Early onset insulin-dependent diabetes mellitus as an initial manifestation of aceruloplasminaemia

BACKGROUND

Aceruloplasminaemia is an autosomal recessive disorder caused by specific mutations in the ceruloplasmin gene. Aceruloplasminaemia is clinically characterized by diabetes mellitus, pigment degeneration of the retina, and neurological abnormalities, such as cerebellar ataxia, extrapyramidal signs, and dementia. We present a patient with aceruloplasminaemia who, until progressive neurological abnormalities were noticed, had been treated for more than 30 years as having Type 1 diabetes mellitus requiring multiple insulin injection therapy.

CASE REPORT

The patient was a 58-year-old man. At the age of 23 years, he developed diabetes that required multiple insulin injection therapy. At the age of 39 years, he was commenced on continuous subcutaneous insulin infusion (CSII) therapy. Despite CSII therapy, the patient's blood glucose levels were poorly controlled (HbA(1c), approximately 9.5%). He was diagnosed as having aceruloplasminaemia at 58 years of age when he presented with progressive cerebellar ataxia, extrapyramidal signs of recent onset and pigment degeneration of the retina.

CONCLUSIONS

It is possible that some diabetic patients with aceruloplasminaemia are mistakenly diagnosed as having Type 1 diabetes mellitus, as they have reduced insulin secretion and develop diabetes at a younger age, before neurological abnormalities associated with aceruloplasminaemia are apparent. Therefore, aceruloplasminaemia should be considered in patients with insulin-dependent diabetes mellitus who develop progressive neurological abnormalities of unknown aetiology along with a microcytic hypochromic anaemia and retinal degeneration.

Effects of statins on the adipocyte maturation and expression of glucose transporter 4 (SLC2A4): implications in glycaemic control

AIMS/HYPOTHESIS

Hyperlipidaemia often occurs in patients with type 2 diabetes mellitus. Though HMG-CoA reductase inhibitors (statins) are widely used for controlling hypercholesterolemia, atorvastatin has also been reported to have an adverse effect on glucose metabolism. Based on these findings, the aim of this study was to investigate the effects of statins on adipocytes, which play pivotal roles in glucose metabolism.

METHODS

In 3T3-L1 cells, effects of statins on adipocyte maturation were determined morphologically. Protein and mRNA levels of SLC2A4 and adipocyte marker proteins were determined by immunoblotting and RT-PCR, respectively. Type 2 diabetic NSY mice were treated with atorvastatin for 15 weeks, followed by glucose and insulin tolerance tests and examination of SLC2A4 expression in white adipose tissue (WAT). Seventy-eight Japanese subjects with type 2 diabetes and hypercholesterolaemia were treated with atorvastatin (10 mg/day), and its effects on lipid and glycaemic profiles were measured 12 weeks after treatment initiation.

RESULTS

Treatment with atorvastatin inhibited adipocyte maturation, SLC2A4 and C/EBPalpha expressions and insulin action in 3T3-L1 cells. Atorvastatin also attenuated SLC2A4 and C/EBPalpha expressions in differentiated 3T3-L1 adipocytes. These effects were reversed by L. mevalonate or geranylgeranyl pyrophosphate. In NSY mice, atorvastatin accelerated glucose intolerance as a result of insulin resistance and decreased SLC2A4 expression in WAT. In addition to improving hyperlipidaemia, atorvastatin treatment significantly increased HbA(1c) but not fasting glucose levels in diabetic patients, and this effect was greater in the non-obese subgroup.

CONCLUSIONS/INTERPRETATION

These results demonstrate that atorvastatin attenuates adipocyte maturation and SLC2A4 expression by inhibiting isoprenoid biosynthesis, and impairs glucose tolerance. These actions of atorvastatin could potentially affect the control of type 2 diabetes.

Long-term cognitive and neuropsychological symptoms after global cerebral ischemia in Mongolian gerbils

The objective of this study was to establish a rodent model of vascular dementia that showed long-term cognitive and neuropsychological deficits, and to correlate those behavioral deficits with the patterns of ischemic lesions, thus providing a platform for future testing of potential therapeutic agents. In Mongolian gerbils, either 5-minute single bilateral common carotid artery occlusion (SBCCAO) or repetitive bilateral common carotid artery occlusion (two 7-minute occlusions, RBCCAO) was induced, and the behavioral deficits were evaluated using 2 tests: a modified open-field test with an escape zone to evaluate changes in anxiety and locomotor activity, and a T-maze test to assess cognitive dysfunction. SBCCAO did not induce anxiety changes but caused transient locomotor hyperactivity and mild cognitive deficits. Only pyramidal neuronal death was found in the bilateral CA1 sector of the hippocampus following SBCCAO. In contrast, RBCCAO induced persistent locomotor hyperactivity, reduced anxiety, and caused severe cognitive deficits at 4 weeks post-ischemia. RBCCAO caused significant atrophy associated with diffuse selective neuronal death in the bilateral cerebral cortex and caudate nucleus, as well as the CA1 region. The repetitive ischemia model appears to be a potentially useful platform for the long-term analysis of cognitive and neuropsychological symptoms associated with vascular dementia.

Neurological dysfunctions versus apparent diffusion coefficient and T2 abnormality after transient focal cerebral ischemia in Mongolian gerbils

We examined temporal profiles of neurological dysfunctions and compared them with apparent diffusion coefficient (ADC) and T2 changes in ischemic cortical regions after transient focal cerebral ischemia in Mongolian gerbils. Mongolian gerbils (n = 7) underwent right common carotid artery occlusion for 20 minutes. Asymmetric motor behavior and unilateral somatosensory dysfunction were quantified by the elevated body swing test and the bilateral asymmetry test at 0, 2, 3, and 8 days after ischemia. The results were compared to the ADC and T2 changes in the primary motor cortex and the somatosensory cortex. Transient motor dysfunction was observed at day 2 after ischemia. MRI revealed transient and mild ADC decrease without T2 increase at day 2 after ischemia in the primary motor cortex. Persistent somatosensory dysfunction was observed at 2, 3, and 8 days after ischemia, which corresponded to a moderate ADC decrease, and a mild T2 increase in the primary somatosensory cortex at days 2 and 3 after ischemia. Time profiles of neurological deficits concurred with ADC changes of the post-ischemic cortex responsible for the deficits. The post-ischemic lesions responsible for the neurological deficits were detectable by using ADC mapping in the acute phase after transient focal cerebral ischemia.

Time profile of eosinophilic neurons in the cortical layers and cortical atrophy

Eosinophilic neurons (ENs) appear in the post-ischemic cortex; however, whether there are differences in the time profile for different cortical layers and the fate of the cortex with ENs is largely unknown. We examined the time profile of ENs in different cortical layers and evolution of cortical atrophy after transient cerebral ischemia in Mongolian gerbils. Unilateral forebrain ischemia was induced twice by 10-minute unilateral common carotid artery occlusions. Brains at 24 hours, 4 days, and 2, 4, and 16 weeks post-ischemia were prepared for morphometric analysis. Quantitative analysis of ENs in regions of interest in the rostral and caudal cortex showed the highest number of ENs at 4 days post-ischemia in layers 3 and 6. Reduction in ENs after this peak was slower in layer 6 than in layer 3 in both rostral and caudal cortex, and this difference was significant in layer 6 of the caudal cortex. Infarcts with significant atrophy appeared in the rostral cortex. In the caudal cortex, only selective neuronal death with mild but distinct atrophy was observed. We observed a significant difference between cortical layers in the time profile of ENs in the post-ischemic cortex. Selective neuronal death without infarction was sufficient to induce cortical atrophy after transient cerebral ischemia.

Unilateral spatial neglect and memory deficit associated with abnormal beta-amyloid precursor protein accumulation after lateral fluid percussion injury in Mongolian gerbils

The purpose of this study was to investigate cognitive/memory dysfunctions and the pathological process contributing to such dysfunction following moderate lateral fluid percussion injury (LFPI) in Mongolian gerbils. Mongolian gerbils were subjected to moderate LFPI (1.3 1.6 atm). During 7 days post-trauma, spatial cognitive and memory dysfunctions were evaluated by T-maze test (TMT). At 6 hours, 24 hours, and 7 days post-injury, animals were sacrificed and the brains were prepared for Kluver-Barrera staining and immunostaining of beta-amyloid precursor protein (APP). In LFPI animals, the spontaneous alternation rate in the TMT remained below the random alternation rate (< 50%) on all post-injury test days. These animals also showed a transient tendency to choose only the right arm (ipsilateral to the injury) in the TMT at 6 hours and 24 hours after injury. Significant accumulation of APP was found widespread in the ipsilateral hemisphere including directly injured cortex, subcortical white matter, and hippocampal formation at 6 hours and 24 hours post-injury, while on day 7, the increased immunoreactivity of APP subsided. These results suggest that the widespread axonal degeneration of the white matter might contribute to the unilateral spatial neglect and memory deficit in the acute stage after LFPI.