Carotid artery occlusion and colateral circulation in C57black/6J mice detected by synchrotron radiation microangiography

Using monochromatic synchrotron radiation, we performed microangiography inC57BL/6J mice and investigated their vasculature after unilateral and bilateral carotidartery occlusion. Bilateral occlusion of the carotid artery was made by a ligation of theleft common carotid artery followed by a ligation of the right internal carotid artery(ICA) two days later (n=12). Five days after the second surgery, angiography wasperformed. Unilateral occlusion was made by clipping the right ICA and thenangiography was performed immediately (n=5). The control mice did not undergo anyocclusion (n=5). We removed the brain of the bilateral occlusion mice afterangiography and examined the infarction area. The cerebral microvessels in all animalswere clearly visualized. In the control mice, the posterior communicating artery (Pcom)was not visualized. In the unilateral occlusion mice, the anastomosis of thepterygopalatine artery (PPA) and the external carotid artery (ECA) were recognized.The PPA is thus considered to play a role in the collateral vessel between the ICA andthe ECA. The Pcom was not visualized. In the bilateral occlusion mice, the Pcom wasobserved either unilateraly (n=5) or bilateraly (n=5). The Pcom supplied blood flow tothe anterior circulation from the vertebrobasilar arteries. The bilateral occlusion micethat had at least one visualized Pcom did not have any infarction. We could successfullyvisualize the cerebral vasculature of normal mice and carotid artery occluded mice inan in vivo study. Microangiography can demonstrate the development of vasculatureand the blood flow dynamics in mice

Low-dose Warfarin Functions as an Immunomodulator to Prevent Cyclophosphamide-induced NOD Diabetes

Warfarin has been used as an anticoagulant for a long time. Recently, the pleiotropic effect of warfarin has been investigated. As low-dose warfarin has been reported to have anti-inflammatory effect through suppression of IL-6 secretion and inhibit the immune-associated signal between Tyro3 and its ligand, Gas6, the effect of low-dose warfarin on autoimmune diabetes in NOD mice was examined. To investigate the anti-inflammatory effect of warfarin, IL-6 secretion by splenocytes was examined in the presence of various concentrations of warfarin. Low concentration of warfarin inhibited IL-6 secretion. mRNA expression of Rse, one of the Tyro3 receptor family members, and Gas6 were analyzed in NOD mice. It was detected in islets, splenocytes and bone-marrow derived dendritic cells. 0.25 mg/l or 0.50 mg/l of warfarin was orally administered to NOD mice as a cyclophosphamide-induced diabetes model. Oral administration of warfarin at much lower doses than those clinically used as an anticoagulant significantly reduced the degree of insulitis and diabetes incidence in this model. We previously demonstrated that anti-FasL Ab-treatment led to complete prevention of autoimmune diabetes in NOD mice. As Fas/FasL signaling is reported to be essential for cyclophosphamide-induced diabetes model, we extracted RNA from lymphocytes of the inguinal lymph nodes of anti-FasL Ab-treated NOD mice and performed real-time PCR to determine expression of Rse gene. Interestingly, the expression of Rse gene related to the blockade of Fas/FasL signaling was reduced to less than half the level of untreated mice. In conclusion, low-dose warfarin is a potential immunomodulator which can prevent autoimmune diabetes. Type 1 diabetes is a chronic autoimmune disease caused by autoreactive T cells promoting the specific destruction of insulin-producing β cells of the pancreatic islets (1,6). Nonobese diabetic (NOD) mouse is an animal model of human autoimmune diabetes (19). In the NOD mouse, diabetes develops as the result of a chronic inflammation that starts with leukocytic infiltration of islets from 3-5 weeks of age and gradually exacerbates until hyperglycemia develops after 16 weeks of age in a high percentage of female mice. Warfarin has been widely used for a long time as an oral anticoagulant agent. In addition, Kater et al. reported the pleiotropic effect of low-dose warfarin related with inflammation, demonstrating that low-dose warfarin inhibited inflammatory signal transduction through suppression of TNF-α induced IL-6 secretion from murine macrophages (12)

Predictive Factors for Hospitalized and Institutionalized Care-giving of the Aged Patients with Diabetes Mellitus in Japan

To identify predictive factors for hospitalized and institutionalized care-giving among a group of aged patients with diabetes mellitus in Japan, retrospective chart review was performed in 288 diabetic subjects aged 65 years or older. Independent variables, based on the chart review, were age, sex, diagnosis, diabetic control and complications. Comprehensive geriatric assessment was performed to obtain information on the functional capacity and demographic variables, including physical and mental function, and socioeconomic status. 131 diabetic patients were considered as frail elderly and characterized for their higher age, longer duration of diabetes, higher frequency of insulin use, lower cognitive function, and lower QOL, in comparison with those of non-frail patients. All non-frail diabetic patients were independently treated at their homes, while 38 subjects out of 131 frail diabetic patients were hospitalized or institutionalized. Apparent clinical features of hospitalized/institutionalized patients were higher age, higher serum creatinine, and higher prevalence of stroke episodes, advanced cognitive decline and absence of key caregiver in the family members, in comparison with those of in-home frail diabetic patients. The predicted probabilities from the multivariate logistic regression analysis in predicting hospitalized and institutionalized care-giving were as follows: Log p/(1 - p) = -19.801x1 - 54.269x2 + 721.405; where x1 = cognitive function (score), x2 = social support (score). Receiver operating characteristic curve analysis revealed a satisfactory discrimination for hospitalized and institutionalized care-giving in frail diabetic elderly with 92.9% of sensitivity and 91.4% of specificity, when the cutoff point of the model was set at 0.992. We concluded that cognitive decline and low social support are the predictive for hospital and institutional care-giving, and that demographic and mental information as well as diagnostic data should be analyzed to predict the hospitalization/institutionalization among frail diabetic elderly

The Double-edged Effect of Insulin on the Neuronal Cell Death Associated with Hypoglycemia on the Hippocampal Slice Culture

It is well known that the central nervous system (CNS) is vulnerable tohypoglycemia and hyperglycemia. Insulin is indispensable for serum glucose controland diabetes patients are on the relative or absolute deficient state of insulin. The roleof insulin on the CNS, however, has not been fully elucidated, yet. To reveal the roleof insulin on the neuronal survival, we have used in vitro system of an organotypichippocampal slice culture from rat, and examine the neuronal cell death at the variousglucose concentrations in the presence or absence of insulin. When glucoseconcentrations is varied to 0, 1, 3, 5 and 30mM in the incubation medium, the neuronalcell death was minimum at 5mM, and no neuronal survival was observed under 1mMon the CA1. On the dentate gyrus granule cells (DG), on the other hand, thesignificant neuronal survival was observed even as low as 1mM. In the presence of1nM concentration of insulin, the neuronal cell death curve showed the U-shape, andthe minimum death point was 3-5mM glucose concentrations at the CA1. At the DG,insulin did not show the protective effect up to 48 hours culture regardless of glucoseconcentration. In the absence of glucose, insulin accelerated the neuronal cell deathboth in the CA1 and DG. We concluded that insulin has a double-edged effect on theneuronal cell death dependent on glucose concentration, and that the CA1 and the DGhave a different sensitivity to insulin in terms of cell survival

Predictive Factors for Hospitalized and Institutionalized Care-giving of the Aged Patients with Diabetes Mellitus in Japan

To identify predictive factors for hospitalized and institutionalized care-giving among a group of aged patients with diabetes mellitus in Japan, retrospective chart review was performed in 288 diabetic subjects aged 65 years or older. Independent variables, based on the chart review, were age, sex, diagnosis, diabetic control and complications. Comprehensive geriatric assessment was performed to obtain information on the functional capacity and demographic variables, including physical and mental function, and socioeconomic status. 131 diabetic patients were considered as frail elderly and characterized for their higher age, longer duration of diabetes, higher frequency of insulin use, lower cognitive function, and lower QOL, in comparison with those of non-frail patients. All non-frail diabetic patients were independently treated at their homes, while 38 subjects out of 131 frail diabetic patients were hospitalized or institutionalized. Apparent clinical features of hospitalized/institutionalized patients were higher age, higher serum creatinine, and higher prevalence of stroke episodes, advanced cognitive decline and absence of key caregiver in the family members, in comparison with those of in-home frail diabetic patients. The predicted probabilities from the multivariate logistic regression analysis in predicting hospitalized and institutionalized care-giving were as follows: Log p/(1 - p) = -19.801x1 - 54.269x2 + 721.405; where x1 = cognitive function (score), x2 = social support (score). Receiver operating characteristic curve analysis revealed a satisfactory discrimination for hospitalized and institutionalized care-giving in frail diabetic elderly with 92.9% of sensitivity and 91.4% of specificity, when the cutoff point of the model was set at 0.992. We concluded that cognitive decline and low social support are the predictive for hospital and institutional care-giving, and that demographic and mental information as well as diagnostic data should be analyzed to predict the hospitalization/institutionalization among frail diabetic elderly

Re-evaluation of Clinical Features and Risk Factors of Acute Ischemic Stroke in Japanese Longevity Society

Age is an important factor correlated with stroke prevalence and independently influences stroke outcome especially in Japanese longevity society. To re-evaluate the characteristics of acute ischemic stroke in the old-old, analyses of clinical data on 426 patients registered at a Japanese tertiary emergency hospital were performed under appropriate statistical methods. Clinical features, stroke subtypes, current-known risk factors for stroke, time from onset to arrival, the National Institute of Health Stroke scale (NIHSS) score on admission, length of hospital stay, modified Rankin Scale (mRS) at discharge were compared between two stratified groups by age-at-onset (≧75 and < 75 years old). Significant differences were demonstrated in categories of sex, NIHSS score, length of hospital stay and m-RS. Current-known risk factors for stroke except atrial fibrillation were not prominent in the elderly group. Our study revealed that clinical phenotype and outcome in stroke patients would have been modified and re-evaluation of risk factors is necessary for prevention of ischemic stroke in Japanese longevity society

Neuroprotective Effect of D-Fructose-1,6-Bisphosphate against beta-Amyloid Induced Neurotoxicity in Rat Hippocampal Organotypic Slice Culture : Involvement of PLC and MEK/ERK Signaling Pathways

D-fructose-1,6-bisphosphate (FBP) is an endogenous intermediate of glycolyticpathway which has potent neuroprotective effect against various neurotoxic insults.This study examined whether FBP could antagonize the neurotoxicity induced byamyloid β-peptide (Aβ) in rat hippocampal organotypic slice cultures, and the possiblemechanism was also explored. Treatment with FBP (concentration ranges from 1.7 mMto 10 mM) significantly decreased the cell death in hippocampal slices in the presence ofAβ at 24h, 48h and 72h, and this neuroprotective effect of FBP against Aβ&#61472; was not in adose-dependent manner, FBP 3.5 mM has better neuroprotective effect than that ofother FBP concentration groups. Treatment with FBP slightly but significantlyincreases the ATP levels in hippocampal slices in the presence of Aβ. However, theincrement of ATP levels was similar among various FBP concentration groups.Neuroprotective effect of FBP 3.5 mM against Aβ induced neurotoxicity inhippocampal slices was attenuated by addition of phospholipase C (PLC) inhibitor,U73122, mitogen activated extracellular signal protein kinase (MEK) inhibitor, U0126,or extracellular signal activated protein kinase (ERK) inhibitor, PD98059 at 24h, 48hand 72h. However, co-treatment with these three kinds of inhibitors did not change theFBP's effect on ATP levels. Our results suggested FBP has neuroprotective effectagainst Aβ induced neurotoxicity in hippocampal slice cultures, and FBP plays role notonly as an alternative energy source, but also a modulator of PLC and MEK/ERKpathways to regulate the cellular response and survival