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1.
J Nutr Health Aging ; 26(7): 681-687, 2022.
Article in English | MEDLINE | ID: mdl-35842758

ABSTRACT

OBJECTIVES: We aimed to examine the association of muscle evaluation, including muscle ultrasound, with hospital-associated disability (HAD), focusing on ADL categories. DESIGN: A prospective observational cohort study. SETTING AND PARTICIPANTS: We recruited patients aged 65 years or older who were admitted to the geriatric ward of an acute hospital between October 2019 and September 2021. MEASUREMENTS: Handgrip strength, bioimpedance analyzer-determined skeletal muscle mass, bilateral thigh muscle thickness (BATT), and the echo intensity of the rectus femoris on muscle ultrasound were performed as muscle assessments. HAD was evaluated separately for mobility impairments and self-care impairments. RESULTS: In total, 256 individuals (mean age, 85.2 years; male sex, 41.8%) were analyzed. HAD in mobility was more common than HAD in self-care (37.5% vs. 30.0%). Only BATT was independently associated with HAD in mobility in multiple logistic regression analysis. There was no significant association between muscle indicators and HAD in self-care. CONCLUSION: A lower BATT was associated with a higher prevalence of HAD in mobility, suggesting the need to reconsider muscle assessment methods in hospitalized older adults. In addition, approaches other than physical may be required, such as psychosocial and environmental interventions to improve HAD in self-care.


Subject(s)
Sarcopenia , Aged , Aged, 80 and over , Disability Evaluation , Hand Strength , Hospitals , Humans , Male , Muscle Strength/physiology , Muscle, Skeletal/diagnostic imaging , Prospective Studies , Sarcopenia/epidemiology
2.
J Neurol Neurosurg Psychiatry ; 82(11): 1186-94, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21478205

ABSTRACT

BACKGROUND: Progression of silent brain infarctions (SBIs) and white-matter lesions (WMLs) seen on brain MRI is associated with an increased risk of cognitive impairment, but their relation to endothelial and inflammatory markers is unknown in type 2 diabetes mellitus. METHODS: In 190 type 2 diabetic outpatients (mean age 62.7 years), the authors related baseline levels of soluble intercellular adhesion molecule-1 (sICAM-1) and high-sensitivity C-reactive protein (hs-CRP) to subsequent brain MRI findings and cognitive function. The authors assessed incident SBIs and changes in periventricular and subcortical WMLs (PVWMLs and SCWMLs) on MRI performed at baseline and 3 and 6 years. Neuropsychological tests were administered to 83 patients older than 65 years at 6 years. This present study represents an extension of the authors' previously published study. RESULTS: SBIs were observed in 46 patients (24.2%), PVWMLs in 93 (48.9%) and SCWMLs in 87 (45.8%) on baseline MRI. After adjustment for age, gender, hypertension, duration of diabetes, baseline MRI findings and medication use, the relative odds associated with a 1SD increase in sICAM-1 levels at baseline were 1.67 (95% CI 1.02 to 3.05) for SBI progression and 2.17 (95% CI 1.29 to 3.62) for PVWML progression at 6 years. In contrast, baseline hs-CRP levels were significantly associated with SBI progression only at 3 years. Significant trends were observed between quartiles of sICAM-1 at baseline and scores in Digit Symbol substitution (p for trend=0.01). CONCLUSIONS: The findings suggest that higher sICAM-1 levels are associated with SBI and PVWML progression, and may predict impairment in psychomotor function in type 2 diabetes.


Subject(s)
Brain Ischemia/pathology , Cerebral Small Vessel Diseases/pathology , Diabetes Mellitus, Type 2/complications , Endothelium, Vascular/pathology , Aged , Brain/pathology , Cerebral Small Vessel Diseases/complications , Cognition Disorders/pathology , Diabetes Complications , Diabetes Mellitus, Type 2/pathology , Disease Progression , Female , Humans , Inflammation , Longitudinal Studies , Magnetic Resonance Imaging/methods , Male , Middle Aged
3.
J Prev Alzheimers Dis ; 8(4): 465-476, 2021.
Article in English | MEDLINE | ID: mdl-34585222

ABSTRACT

BACKGROUND/OBJECTIVES: The Japan-multimodal intervention trial for prevention of dementia (J-MINT) is intended to verify the effectiveness of multi-domain interventions and to clarify the mechanism of cognitive improvement and deterioration by carrying out assessment of dementia-related biomarkers, omics analysis and brain imaging analysis among older adults at high risk of dementia. Moreover, the J-MINT trial collaborates with partnering private enterprises in the implementation of relevant interventional measures. This manuscript describes the study protocol. DESIGN/SETTING: Eighteen-month, multi-centered, randomized controlled trial. PARTICIPANTS: We plan to recruit 500 older adults aged 65-85 years with mild cognitive impairment. Subjects will be centrally randomized into intervention and control groups at a 1:1 allocation ratio using the dynamic allocation method with all subjects stratified by age, sex, and cognition. INTERVENTION: The multi-domain intervention program includes: (1) management of vascular risk factors; (2) group-based physical exercise and self-monitoring of physical activity; (3) nutritional counseling; and (4) cognitive training. Health-related information will be provided to the control group every two months. MEASUREMENTS: The primary and secondary outcomes will be assessed at baseline, 6-, 12-, and 18-month follow-up. The primary outcome is the change from baseline to 18 months in a global composite score combining several neuropsychological domains. Secondary outcomes include: cognitive change in each neuropsychological test, incident dementia, changes in blood and dementia-related biomarkers, changes in geriatric assessment including activities of daily living, frailty status and neuroimaging, and number of medications taken. CONCLUSIONS: This trial that enlist the support of private enterprises will lead to the creation of new services for dementia prevention as well as to verify the effectiveness of multi-domain interventions for dementia prevention.


Subject(s)
Cognition/physiology , Cognitive Dysfunction/therapy , Dementia/prevention & control , Exercise , Geriatric Assessment , Activities of Daily Living , Aged , Aged, 80 and over , Exercise/physiology , Female , Humans , Japan , Male , Neuropsychological Tests/statistics & numerical data , Nutrition Assessment , Risk Factors
4.
J Nutr Health Aging ; 24(3): 312-318, 2020.
Article in English | MEDLINE | ID: mdl-32115613

ABSTRACT

OBJECTIVES: The aim of this study was to examine the impact of the combination of physical frailty and social isolation on falling in community-dwelling older adults. DESIGN: A cross-sectional study of data obtained at registration in a randomized control trial. SETTING: Community-based study of participants recruited from Toyota, Japan. PARTICIPANTS: 380 community-dwelling older adults (47.9% women, mean age = 72.3 ± 4.6 years). MEASUREMENTS: Participants were categorized as non-frail or pre-frail/frail based on the Fried frailty criteria (slowness, weakness, exhaustion, low activity, and weight loss). Social isolation was examined using the Lubben Social Network Scale (LSNS-6), and scores lower than 12 points indicated social isolation. Participants were divided into four groups depending on pre-frail/frail status and social isolation, and experiences of multiple falls over the past year were compared between the groups. RESULTS: Participants were classified into robust (n = 193), physical frailty (PF; n = 108), social isolation (SI; n = 43), and PF with SI (PF+SI; n = 36) groups. A total of 38 (10.0%) participants reported multiple falls. Logistic regression analysis showed that PF and SI groups were not independently associated with falling (PF: OR 1.64, 95% CI 0.65-4.16, SI: OR 2.25, 95% CI 0.77-6.58), while PF+SI group was significantly associated with falling compared with the robust group (OR 3.06, 95% CI 1.00-9.34, p = 0.049) after controlling for confounding factors. CONCLUSION: Our findings support the assertion that coexistence with physical frailty and social isolation were associated with falling in the older adults.


Subject(s)
Accidental Falls/statistics & numerical data , Frail Elderly/statistics & numerical data , Social Isolation/psychology , Aged , Aged, 80 and over , Cross-Sectional Studies , Female , Geriatric Assessment , Humans , Male
5.
J Nutr Health Aging ; 22(4): 549-554, 2018.
Article in English | MEDLINE | ID: mdl-29582896

ABSTRACT

OBJECTIVES: A number of studies have reported that frailty is cross-sectionally associated with cognitive decline and is also a risk for future cognitive decline or dementia; however, there have been only a few studies that focus on the association between prefrailty and cognitive dysfunction. In the current study, we investigated the association between prefrailty and cognition. DESIGN: A cross-sectional study of the data obtained at registration in a randomized control trial. SETTING: Toyota, Japan. PARTICIPANTS: Community-dwelling older subjects (male 54.6%) who had cognitive complaints. MEASUREMENTS: A battery of neuropsychological and physical assessments were performed. Prefrailty was defined as exhibiting one or two of the five Fried criteria (weight loss, exhaustion, weakness, slow gait speed and low physical activity). We performed a multiple regression analysis to investigate the associations of cognitive performance with prefrailty, adjusting for the factors that were significantly different between the robust and prefrailty groups. To assess the cognitive attributes that were significantly associated with prefrailty, logistic analysis was performed to see if one specific criterion of the five frailty criteria was associated with cognitive performance. RESULTS: The study subjects included 183 prefrail and 264 robust individuals. The prefrail subjects with cognitive complaints were older, less educated, more depressive, and more likely to have diabetes mellitus than the robust subjects. The prefrail subjects had lower performance in a wide-range of cognitive domains, and after adjustments for age, education, depressive mood, and diabetes mellitus, prefrailty was associated with a decline in delayed memory and processing speed. Among the components of the Fried criteria, slow gait speed and loss of activity were significantly associated with slow processing speed as assessed by the digit symbol substitution test. CONCLUSION: The current results demonstrated that prefrailty was associated with worse memory and processing speed performance, but not with other cognitive domains.


Subject(s)
Cognitive Dysfunction/epidemiology , Geriatric Assessment/methods , Aged , Cross-Sectional Studies , Female , Frail Elderly/statistics & numerical data , Frailty , Humans , Male , Urban Population
6.
J Nutr Health Aging ; 20(4): 453-7, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26999247

ABSTRACT

OBJECTIVES: Older patients receiving home medical care often have declining functional status and multiple disease conditions. It is important to identify the risk factors for care transition events in this population in order to avoid preventable transitions. In the present study, therefore, we investigated the factors associated with discontinuation of home medical care as a potentially preventable care transition event in older patients. METHODS: Baseline data for participants in the Observational study of Nagoya Elderly with HOme MEdical (ONEHOME) study and data on the mortality, institutionalization, or hospitalisation of the study participants during a 2-year follow-up period were used. Discontinuation of home care was defined as admission to a hospital for any reason, institutionalization, or death. Univariate and multivariate Cox hazard models were used to assess the association of each of the factors with the discontinuation of home care during the observational period. The covariates included in the multivariate analysis were those significantly associated with the discontinuation of home care at the level of P<0.05 in the univariate analysis. RESULTS: The univariate Cox hazard model revealed that a low hemoglobin level (< 11g/dL), low serum albumin level (< 3g/dL), higher Charlson Comorbidity Index score, and low Mini Nutritional Assessment Short Form score (< 7) were significantly associated with the discontinuation of home care. A multivariate Cox hazard model including these four factors demonstrated that all four were independently associated with home-care discontinuation. CONCLUSIONS: The present results demonstrated that anemia, hypoalbuminemia, malnourishment, and the presence of serious comorbidities were associated with the discontinuation of home medical care among low-functioning older patients.


Subject(s)
Geriatric Assessment , Home Care Services/statistics & numerical data , Hospitalization/statistics & numerical data , Aged , Aged, 80 and over , Comorbidity , Female , Follow-Up Studies , Hemoglobins/analysis , Humans , Male , Nutrition Assessment , Proportional Hazards Models , Risk Factors , Serum Albumin/analysis
7.
Mech Ageing Dev ; 116(2-3): 77-93, 2000 Jul 31.
Article in English | MEDLINE | ID: mdl-10996008

ABSTRACT

The age-related loss of striatal dopamine D(2) receptors (D(2)R) has been observed in numerous species, including rodents, monkeys, and man, and is partly responsible for impaired motor function in aged mammals. We have developed an adenoviral vector designed for intracerebral transfer of cDNA for D(2)R. Results of in vitro studies demonstrated that the vector produced abundant message for D(2)R and that the vector was membrane bound and capable of binding appropriate ligand. Results of in vivo studies provided clear evidence of D(2)R production when injected into the striatum of rats. The D(2)R produced were capable of binding appropriate ligand. In addition, evidence of functional receptors was produced by demonstrating apomorphine-induced rotational behavior in rats receiving a unilateral injection of the vector. Despite these successes, we have been unable to demonstrate improvement in the motor behavior of aged rats receiving bilateral injections of the vector. A major problem with this vector as with similar adenoviral vectors is the loss of expression beginning 3-5 days after injection to undetectable levels at 21 days. Because of the lack of motor functional effects in aged rats and the loss of expression of the vector, other strategies for development of the vector are being pursued. Regarding functional effects, we have examined the feasibility of manipulating hippocampal acetylcholine (ACh) release through D(2)R manipulation to improve memory performance. Using microdialysis, we have demonstrated in vivo in rats that treatment with a D(2)R agonist increases hippocampal ACh release while treatment with a D(2)R antagonist attentuates this effect as well as impairs performance in a complex maze task. In addition, a D(2)R null mutant mouse is being used to examine possible therapeutic effects of the vector. These mice show specific motor deficits. Recent studies using positron emission tomography have also demonstrated the feasibility of in vivo imaging of the vector. Thus, use of adenoviral vectors specific for neurotransmitter receptors can provide a highly useful research tool for examining age-related alterations in behavioral function and a possible strategy for therapeutic intervention.


Subject(s)
Adenoviruses, Human , Genetic Vectors , Receptors, Dopamine D2/genetics , Telencephalon , Acetylcholine/metabolism , Animals , Gene Expression , Gene Transfer Techniques , Hippocampus/metabolism , Humans , Injections , Learning/physiology , Mice , Rats , Rats, Inbred F344 , Rats, Sprague-Dawley , Receptors, Dopamine D2/biosynthesis , Receptors, Dopamine D2/metabolism
8.
Neuroscience ; 103(1): 27-33, 2001.
Article in English | MEDLINE | ID: mdl-11311785

ABSTRACT

In the current study we focus on the involvement of dopamine D(2) receptors in the ventral hippocampus in memory performance and acetylcholine release. Using the aversively motivated 14-unit T-maze (Stone maze) the injection of raclopride, a D(2) receptor antagonist, into the ventral hippocampus (8 microg/kg) was found to impair memory performance. Co-injection of quinpirole, a D(2) receptor agonist (8 microg/kg), overcame the impairment in performance. Microdialysis study revealed that quinpirole infusion (10-500 microM) into the ventral hippocampus stimulated acetylcholine release in a dose-dependent manner, and systemic injection of quinpirole (0.5 mg/kg, i.p.) also stimulated acetylcholine release in the ventral hippocampus. Infusion of eticlopride, another D(2) receptor antagonist, into the ventral hippocampus suppressed acetylcholine release in the hippocampus induced by systemic injection of quinpirole. Taken together, we suggest that D(2) receptors in the ventral hippocampus are involved in memory performance, possibly through the regulation of acetylcholine.


Subject(s)
Acetylcholine/metabolism , Hippocampus/metabolism , Maze Learning/physiology , Receptors, Dopamine D2/physiology , Animals , Avoidance Learning/physiology , Dopamine Agonists/pharmacology , Dopamine Antagonists/pharmacology , Food , Male , Microdialysis , Rats , Rats, Inbred F344 , Receptors, Dopamine D2/drug effects , Reward
9.
Neuroscience ; 121(2): 479-86, 2003.
Article in English | MEDLINE | ID: mdl-14522006

ABSTRACT

Overexpression of dopamine D(2) receptors by adenoviral vector-mediated gene transfer in the rat striatum was evaluated by positron emission tomography in vivo and by ex vivo autoradiography in 5-, 13-, and 24-month-old Fischer 344 rats. Each rat had hemilateral gene transfer of D(2) receptors mediated by adenoviral vectors (AdCMV.DopD(2)R) in the striatum with contralateral striatal injection of control vectors (AdCMV.LacZ). At day 2 or 3 after vector injection positron emission tomography or ex vivo autoradiography was performed. The binding potential of a radiolabeled D(2) receptors ligand, [11C]raclopride, was significantly higher in the D(2) receptors gene-transferred striatum than the control side in each age group at a similar degree. The binding potential in the AdCMV.DopD(2)R-injected striatum of 24-month-old rats was similar to that in the AdCMV.LacZ-injected striatum of 5-month-old rats (0.99+/-0.14 versus 0.91+/-0.08). A significant age-associated decrease of the binding potential of [11C]raclopride was found in the control vector-injected side, and a significant increase of the binding potential in the adenoviral vector-injected side in all three age groups, suggesting no aging effect on the overexpression of D(2) receptors. A group of rats underwent follow-up assessment by positron emission tomography. The overexpression of D(2) receptors decreased with time in all three groups; however, the decrease rate of the D(2) receptors expression was significantly smaller in the 24-month-old group than in the 5-month-old group. We confirmed that the adenoviral vector-mediated gene transfer of D(2) receptors compensated the decreased density of striatal D(2) receptors in the 24-month-old rats up to the level in the control striatum of 5-month-old rats, and the decrease rate of the overexpression was significantly smaller in aged rats.


Subject(s)
Aging/metabolism , Corpus Striatum/metabolism , Receptors, Dopamine D2/metabolism , Tomography, Emission-Computed , Adenoviridae/genetics , Animals , Autoradiography , Binding Sites , Brain Mapping , Carbon Isotopes/pharmacokinetics , Corpus Striatum/diagnostic imaging , Corpus Striatum/virology , Dopamine Antagonists/pharmacokinetics , Follow-Up Studies , Gene Transfer Techniques , Genetic Vectors/genetics , Longitudinal Studies , Male , Raclopride/pharmacokinetics , Rats , Rats, Inbred F344 , Receptors, Dopamine D2/genetics , Time Factors
10.
Exp Gerontol ; 35(9-10): 1373-82, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11113615

ABSTRACT

Several lines of evidence suggest that the cholinergic system in the hippocampus plays a pivotal roll in regulating the peripheral metabolism of glucose and catecholamines. The injection of cholinergic stimulators including neostigmine, the acetylcholine esterase inhibitor, into the third ventricle or the hippocampus induces the elevation of glucose or catecholamines in plasma in rats. Under stress conditions, release of acetylcholine in the hippocampus increases, which coincides with the elevation of plasma glucose and catecholamines. Age-related reduction in responsivity of the cholinergic system in the hippocampus has been well documented. The intrahippocampal neostigmine injection induces significantly attenuated responses in plasma glucose and catecholamines in rats, the finding suggested that changes in cholinergic system activity in the hippocampus could result in alteration of the peripheral metabolism of glucose and catecholamines. In Alzheimer's disease (AD), the most common type of dementia, degeneration of the hippocampal cholinergic system is one of the most robust pathological features. Measurement of plasma catecholamines during a fasting state in the groups of AD subjects, vascular dementia subjects, and non-demented control subjects showed significantly lower plasma epinephrine levels in the AD subjects.


Subject(s)
Alzheimer Disease/blood , Blood Glucose/metabolism , Catecholamines/blood , Acetylcholine/metabolism , Aged , Aged, 80 and over , Aging , Alzheimer Disease/pathology , Animals , Blood Glucose/drug effects , Cholinesterase Inhibitors/pharmacology , Dopamine/blood , Epinephrine/blood , Hippocampus/drug effects , Hippocampus/metabolism , Humans , Neostigmine/pharmacology , Norepinephrine/blood
11.
Exp Gerontol ; 33(7-8): 793-804, 1998.
Article in English | MEDLINE | ID: mdl-9951623

ABSTRACT

We have investigated the feasibility of using gene therapy to attenuate the age-related decline in striatal dopamine D2 receptors (D2R) associated with reduced motor control. To this end, we have constructed an adenoviral vector containing the cDNA for the rat D2R. When injected into HeLa and HS24 cells in vitro, the vector induced an abundant message for D2R, as demonstrated by Northern analysis, and produced a membrane-bound protein capable of binding a D2R ligand, [3H]spiperone. When injected into rat striatum in vivo, the vector produced a marked increase in D2R near the site of injection, as evidenced by increased [3H]spiperone binding as well as by another more specific ligand, [125I]iodosulpride. The D2R produced in the striatum were functional, as evidenced by rotational behavior induced by a subcutaneous injection of the dopamine agonist, apomorphine. However, we did not observe any significant improvement in motor performance during preliminary experiments in which aged rats received bilateral striatal injections of the vector. In young rats, vector-induced expression of D2R in striatum was increased markedly three to five days after infection, but then declined to baseline levels by day 21. Loss of expression in aged rats proceeded at a somewhat lower rate. Because of the loss of expression and lack of significant performance enhancement in aged rats following vector injection into the striatum, we are now pursuing other strategies. These include functional assessment of the current vector in D2R null mutant mice as well as construction of new vectors that may yield more long-term expression.


Subject(s)
Aging/metabolism , Genetic Therapy , Receptors, Dopamine D2/metabolism , Animals , Feasibility Studies , Mice , Mice, Knockout/genetics , Mice, Knockout/physiology , Rats , Rats, Inbred F344/metabolism , Rats, Sprague-Dawley/metabolism , Receptors, Dopamine D2/genetics , Time Factors
12.
Biochem Pharmacol ; 52(6): 911-6, 1996 Sep 27.
Article in English | MEDLINE | ID: mdl-8781510

ABSTRACT

Interleukin-6 (IL-6) is known to differentiate the rat pheochromocytoma cell line PC12 to neuron-like cells. We examined the effect of IL-6 on the death of PC12 cells. IL-6 significantly blocked the death of PC12 cells by serum deprivation. The protective effect of IL-6 was increased by preincubation of PC12 with IL-6 for 20 hr before serum deprivation. The inhibition of protein synthesis by cycloheximide had no effect on the protective effect of IL-6 on the serum deprivation-induced cell death. IL-6 also inhibited the death of PC12 cells induced by addition of the calcium ionophore A23187 to the culture medium. Specific in situ labeling of DNA cleavage was observed in PC12 cells subjected to both serum deprivation and A23187 for 24 hr. IL-6 inhibited DNA fragmentation in PC12 cells following serum deprivation. These results suggest that the death of PC12 cells induced by serum deprivation or by the addition of calcium ionophore is apoptosis, and that IL-6 blocks apoptosis of PC12 cells.


Subject(s)
Calcium/pharmacology , Cell Death/drug effects , Interleukin-6/pharmacology , PC12 Cells/drug effects , Animals , Dose-Response Relationship, Drug , Ionophores/metabolism , L-Lactate Dehydrogenase/metabolism , Rats
13.
J Neuroendocrinol ; 15(3): 237-41, 2003 Mar.
Article in English | MEDLINE | ID: mdl-12588511

ABSTRACT

Although the involvement of the limbic system in the neuroendocrine responses to some stressors has been documented, the specific role of the entorhinal cortex has not been elucidated. In this study, we investigated the involvement of the entorhinal cortex in stress responses. Fos immunoreactivity, a widely used marker for neuronal activation, was detected in the entorhinal cortex of rats subjected to immobilization stress, whereas no marked staining was observed in the entorhinal cortex of the control and insulin-induced hypoglycaemia groups. Lesion of the entorhinal cortex produced by ibotenic acid significantly attenuated the adrenocorticotropic hormone (ACTH) release evoked by immobilization; however, no significant change in ACTH release was observed in insulin-induced hypoglycaemia. No significant difference between entorhinal-lesioned rats and control rats was observed in blood glucose concentrations when subjected to either immobilization or to insulin-induced hypoglycaemia. Together, these results indicate that the entorhinal cortex is closely involved in the stress response to immobilization but not to insulin-induced hypoglycaemia.


Subject(s)
Entorhinal Cortex/physiology , Hypoglycemia/physiopathology , Stress, Physiological/physiopathology , Adrenocorticotropic Hormone/blood , Animals , Denervation , Entorhinal Cortex/chemistry , Entorhinal Cortex/cytology , Excitatory Amino Acid Agonists , Hypoglycemia/chemically induced , Hypoglycemic Agents , Ibotenic Acid , Immunohistochemistry , Insulin , Male , Neurons/chemistry , Proto-Oncogene Proteins c-fos/analysis , Rats , Rats, Wistar , Restraint, Physical
14.
Neuroreport ; 9(11): 2569-72, 1998 Aug 03.
Article in English | MEDLINE | ID: mdl-9721934

ABSTRACT

Overflow of the neurotransmitter dopamine (DA) in striatum is implicated in the neurodegenerative processes in ischemia, hypoxia and local exposure to high concentrations of excitatory amino acids. However, how DA causes neurotoxicity is not understood. We report that intrastriatal injection of DA (0.5-1 micromol/microl) in Wistar rats produces a robust increase in apoptotic cell death as determined by both a terminal deoxynucleotidyl transferase catalyzed dUTP-biotin nick labeling (TUNEL) and Klenow polymerase catalyzed [32P]dCTP labeled DNA ladder. Cells in which apoptosis was induced by DA are characterized by condensed chromatin, DNA fragmentation, shrinkage and irregular shapes. The apoptotic cell death induced by DA is not due to the effect of hyperosmolar solution since intrastriatal injection of identical concentrations of NaCl on opposite sides of the same rat brains shows little TUNEL-positive labeling. The number of apoptotic cells is proportional to the amount of DA and length of exposure period. With DA concentrations from 0 to 1 micromol/microl, the maximal toxic effect appears at a concentration of 1 micromol/microl after 24 h exposure. Demonstration of DA-induced apoptosis in vivo may provide a potential molecular mechanism for DA neurotoxicity.


Subject(s)
Apoptosis/drug effects , DNA Damage/drug effects , Dopamine/toxicity , Neostriatum/physiology , Animals , DNA/genetics , DNA/isolation & purification , Dopamine/administration & dosage , In Situ Nick-End Labeling , Injections , Male , Rats , Rats, Wistar
15.
Neuroreport ; 8(16): 3553-8, 1997 Nov 10.
Article in English | MEDLINE | ID: mdl-9427325

ABSTRACT

We investigated the expression and functionality of a previously developed adenoviral vector carrying the rat cDNA for the dopamine D2 receptor (D2R), AdCMV.DopD2R. Comparative analysis of the autoradiographic images from the striatum injected with AdCMV.DopD2R and the contralateral striatum injected with a control vector, AdCMV.Null, in male rats indicated that D2R binding was increased by 40-60% on days 3 and 5 after injection, but then declined to baseline levels by day 21. When injected with apomorphine on days 3 and 7 after vector injection, experimental groups that had received unilateral striatal injections of AdCMV.DopD2R exhibited a distinct and significant laterality in rotational behavior. These results provide the first demonstration of an adenovirally mediated, intracerebral delivery of a functional neurotransmitter receptor.


Subject(s)
Corpus Striatum/physiology , Gene Transfer Techniques , Motor Activity/physiology , Receptors, Dopamine D2/biosynthesis , Rotation , Adenoviridae , Animals , Apomorphine/pharmacology , Functional Laterality , Gene Expression Regulation , Genetic Vectors , Male , Motor Activity/drug effects , Rats , Rats, Sprague-Dawley , Receptors, Dopamine D2/physiology , Recombinant Proteins/biosynthesis , Time Factors
16.
Neuroreport ; 11(4): 743-8, 2000 Mar 20.
Article in English | MEDLINE | ID: mdl-10757512

ABSTRACT

PET was used to provide in vivo imaging of the over-expression of dopamine D2 receptor (D2R) induced by adenovirus vector-mediated gene transfer in rat striatum. The uptake of three kinds of D2R-specific ligands, [11C]raclopride, [11C]nemonapride and [11C]N-methylspiperone, measured by PET was higher in the striatum injected with the vectors for D2R than the contralateral striatum injected with a control vector 2-3 days after injection. However, the uptake of [11C]SCH 23390, a dopamine D1 receptor specific ligand, or [11C]beta-CIT-FP, a dopamine transporter specific tracer, was not different between bilateral striata. Co-injection of excess unlabeled raclopride inhibited the uptake of [11C]raclopride. At day 16 the increased uptake of [11C]raclopride declined to basal level, consistent with past in vitro assessment of this vector. In vivo imaging of D2R will permit longitudinal assessment of the efficiency of this and similar vectors in rat brain that can be related to functional changes being observed.


Subject(s)
Adenoviridae/chemistry , Neostriatum/diagnostic imaging , Receptors, Dopamine D2/chemistry , Animals , Gene Expression Regulation, Viral , Genetic Vectors , Male , Rats , Rats, Inbred F344 , Tomography, Emission-Computed
17.
Brain Res ; 916(1-2): 101-6, 2001 Oct 19.
Article in English | MEDLINE | ID: mdl-11597596

ABSTRACT

This study was designed to determine the effect of the bed nucleus of the stria terminalis (BNST) in hippocampal cholinergic system-mediated activation of the hypothalamo--pituitary--adrenocortical (HPA) axis in the rat. Neurons in the BNST were lesioned by bilateral injection of the cell-selective neurotoxin, ibotenic acid (1.5 microg/microl of solution per side). Two weeks later, neostigmine was microinjected into the rats' hippocampus. Rats in which ibotenic acid had been injected into the BNST showed attenuated expression of c-Fos in the hypothalamic paraventricular nucleus (PVN) and blunted elevation of plasma adrenocorticotropic hormone (ACTH) after microinjection of neostigmine into the hippocampus compared with rats in which saline had been injected into the BNST. The results of this study indicate that the BNST relays signals of hippocampal cholinergic system-mediated activation of the HPA axis in rats.


Subject(s)
Acetylcholine/metabolism , Cholinergic Fibers/metabolism , Hippocampus/metabolism , Hypothalamo-Hypophyseal System/metabolism , Pituitary-Adrenal System/metabolism , Septal Nuclei/metabolism , Stress, Physiological/metabolism , Adrenocorticotropic Hormone/blood , Animals , Cholinergic Fibers/drug effects , Cholinergic Fibers/ultrastructure , Cholinesterase Inhibitors/pharmacology , Excitatory Amino Acid Antagonists/pharmacology , Hippocampus/cytology , Hippocampus/drug effects , Hypothalamo-Hypophyseal System/cytology , Hypothalamo-Hypophyseal System/drug effects , Ibotenic Acid/pharmacology , Immunohistochemistry , Male , Neostigmine/pharmacology , Neurons/cytology , Neurons/drug effects , Neurons/metabolism , Pituitary-Adrenal System/cytology , Pituitary-Adrenal System/drug effects , Proto-Oncogene Proteins c-fos/drug effects , Proto-Oncogene Proteins c-fos/metabolism , Rats , Rats, Wistar , Septal Nuclei/cytology , Septal Nuclei/drug effects , Stress, Physiological/physiopathology
18.
Brain Res ; 892(2): 391-5, 2001 Feb 23.
Article in English | MEDLINE | ID: mdl-11172789

ABSTRACT

We have reported that the microinjection of neostigmine into the hippocampus of rats induced responses similar to stress responses in terms of catecholamines and glucose in plasma. In order to test the hypothesis that hippocampal neostigmine injection is a possible animal model of acute stress responses, we investigated c-Fos expression in the hypothalamic paraventricular nucleus (PVN) and plasma levels of adrenocorticotrophic hormone (ACTH) after hippocampal neostigmine injection and compared these levels with those resulting from stressful conditions such as immobilization and insulin-induced hypoglycemia. The patterns of expression of Fos-ir in the PVN after microinjection of neostigmine into the hippocampus were not different from those seen in the two stressful situations. After microinjection of neostigmine, plasma ACTH levels significantly increased. Taken together, the results of this study indicate that microinjection of neostigmine into the hippocampus is a potential experimental model for acute stress responses.


Subject(s)
Adrenocorticotropic Hormone/blood , Cholinesterase Inhibitors/pharmacology , Gene Expression Regulation/physiology , Genes, fos/genetics , Hippocampus/physiology , Neostigmine/pharmacology , Paraventricular Hypothalamic Nucleus/metabolism , Stress, Psychological/metabolism , Animals , Cholinesterase Inhibitors/administration & dosage , Immobilization , Immunohistochemistry , Male , Microinjections , Neostigmine/administration & dosage , Proto-Oncogene Proteins c-fos/biosynthesis , Rats , Rats, Wistar , Stress, Psychological/blood
19.
Brain Res ; 858(1): 67-70, 2000 Mar 06.
Article in English | MEDLINE | ID: mdl-10700598

ABSTRACT

One of the robust features of brain pathologies of dementia of Alzheimer type (DAT) is the impairment of the hippocampus, especially the cholinergic system. Several animal studies have suggested that the cholinergic system in the hippocampus is involved in the control of the plasma level of catecholamines and glucose. The stimulation of the hippocampal cholinergic system has resulted in the elevation of plasma catecholamines and glucose in rats. In the present study, we measured the plasma level of epinephrine, norepinephrine, dopamine, glucose, and insulin during a fasting state in the morning in hospitalized DAT (n=66), vascular dementia (VD) (n=28), or non-demented (ND) (n=21) females (mean age DAT=82. 49+/-4.98, VD=82.86+/-5.86, ND=82.95+/-7.77, respectively). Statistical analysis showed that the plasma level of epinephrine during a fasting state in DAT subjects was significantly lower than that of ND subjects; however, in VD subjects the level of epinephrine was not different from that of ND subjects. Other values did not differ significantly among the groups.


Subject(s)
Alzheimer Disease/blood , Epinephrine/blood , Aged , Aged, 80 and over , Analysis of Variance , Dementia, Vascular/blood , Dopamine/blood , Fasting/blood , Female , Humans , Norepinephrine/blood
20.
Brain Res ; 881(2): 241-3, 2000 Oct 27.
Article in English | MEDLINE | ID: mdl-11036168

ABSTRACT

We investigated the plasma cortisol levels at a fasting state in elderly female Alzheimer's disease (AD), vascular dementia (VD), and non-demented subjects (n=66, 28 and 21, respectively). Twenty-eight AD subjects were followed for 40 months. The plasma cortisol levels in AD and VD subjects were significantly higher than those of non-demented subjects at baseline. In AD subjects in relatively early stages of the disease [Mini-Mental State Examination (MMSE)], at baseline, high plasma cortisol led to rapid declines in MMSE scores over a 40-month period.


Subject(s)
Alzheimer Disease/blood , Dementia, Vascular/blood , Hydrocortisone/blood , Mental Status Schedule/statistics & numerical data , Aged , Aged, 80 and over , Alzheimer Disease/psychology , Biomarkers/blood , Cross-Sectional Studies , Dementia, Vascular/psychology , Female , Humans , Longitudinal Studies , Regression Analysis
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