The objective of this study was to assess whether reduced glucose metabolism (rCMRGlu) and cognitive functioning could predict development of Alzheimer's disease (AD) in subjects with mild cognitive impairment (MCI). Twenty MCI patients underwent baseline and follow-up investigations of rCMRGlu, as measured by PET, and cognitive function measured by neuropsychological test assessments. Subjects were clinically followed up with an average interval of 36.5 months. Two groups were obtained after the second clinical assessment. Nine patients were diagnosed as AD and classified as progressive MCI (P-MCI), whereas 11 patients remained clinically stable and were classified as stable MCI (S-MCI). There were no differences in demographic variables or baseline MMSE between the two subgroups. Logistic regression indicated the two variables that most effectively predicted future development of AD were rCMRGlu from the left temporoparietal area and performance on the block design. These combined measures gave an optimal 90% correct classification rate, whereas only rCMRGlu or neuropsychology alone gave 75% and 65% correct classification, respectively. Measures of temporoparietal cerebral metabolism and visuospatial function may aid in predicting the evolution to AD for patients with MCI. 相似文献
The birth process induces fetal stress. Stress has profound effects on the immune system, also by acting on the trafficking of leukocytes, a process in which adhesion and chemotaxis are primordial and critical events for the development of effective antimicrobial defenses. The newborn is rapidly challenged by a microflora at the epithelia linings and therefore depending on early, innate immunity onset. The objective of the study was to investigate the immune response in cord blood from newborns in relation to different degrees of fetal stress, with focus on neutrophil chemotaxis. We analyzed in vitro transmigration ability of neutrophils and their CD11b expression, measured total white blood count (WBC) and the major leukocyte populations, interleukin (IL)-8, interferon (IFN)-gamma, and soluble E-Selectin, as well as relevant immuno-modulating hormones in infants born at term after Cesarean section prior to the start of labor (n = 55), normal vaginal delivery (n = 87), and assisted delivery (n = 26). Arterial pH and lactate were used as stress markers. We found that spontaneous and IL-8-induced transmigration ability of neutrophils from newborns after normal delivery was significantly higher compared with that of neutrophils from Cesarean section or from adults. With a progressive increase in fetal stress, there were significant elevations in total WBC, in particular neutrophils and monocytes, as well as an enhanced IL-8 and soluble E-Selectin level. Assisted delivery, associated with the highest degree of fetal stress in addition had an enhanced lymphocyte and monocytes count as well as an increased IFN-gamma level. There were significant direct correlations between neutrophils and monocytes, respectively, with cortisol, beta-endorphin, and prolactin. Interferon-gamma was directly related to dopamine, as well as to the lymphocyte and monocyte count. The setting of the HPA-axis at birth is a promoter of an alarm response and a surge of neuroendocrine immuno-modulating factors that enhances antimicrobial defenses of the newborn. We speculate that IL-8 induced by normal labor may be a priming factor for an increased neutrophil chemotaxis through the pre-activated endothelium of the fetus. Assisted delivery may trigger excessive recruitment of additional inflammatory cells and IFN-gamma release. 相似文献
Four monkeys were exposed to a total of 8 g each of manganese as oxide by repetitive subcutaneous injections during 5 months, after which they were left for 1 week to 6 months before they were sacrificed. All animals developed hyperactive behaviour after about 2 months. About 5 months after the start of the exposure the animals became hypoactive with an unsteady gait, and subsequently an action tremor appeared in some of the animals. The animals lost power in both upper and lower limbs and the movements of the hands and feet were very clumsy. The serum content of manganese rose 10–40 times during the exposure time and the content in brain was generally increased more than 10 times, with the highest content found in globus pallidus and putamen. The observed neurochemical effects were also largest in globus pallidus and putamen. In these regions there was a considerable depletion of dopamine and 3,4-dihydroxyphenylacetic acid, while the homovanillic acid content remained almost unchanged. A severe neuronal cell loss was observed in globus pallidus but not in other regions. This is in accordance with results from the most recent neuropathological study of a human suffering from chronic manganese poisoning [Yamada et al. (1986) Acta Neuropathol 70: 273–278] where globus pallidus was devoid of neuronal cells while the content of pigmented cells in substantia nigra was normal. Our data suggest a reduction in number of dopaminergic nerve terminals, as the activity of the dopamine synthesizing enzyme DOPA-decarboxylase was also lowered. In addition to the effects on the dopaminergic system, a reduced content of 5-hydroxyindole acetic acid was observed in the putamen and globus pallidus. Moreover neurotensin, a neuropeptide with functional connection to the dopaminergic system, was found to be reduced in the putamen. It was remarkable that all the neurochemical effects seen in the putamen were more or less absent from the caudate nucleus. These observations are discussed in relation to what has been found in Parkinsonian and MPTP-lesioned brains. 相似文献
Background. S100B, a plasma marker of brain injury, was compared after coronary artery bypass grafting with and without cardiopulmonary bypass (CPB).
Methods. Fourteen patients with off-pump operations and 18 patients with CPB were compared. Seven patients in the off-pump group underwent a minithoracotomy and received only an arterial graft, whereas 7 patients underwent sternotomy and received both an arterial and one or two vein grafts. S100B was measured in arterial plasma using an immunoassay with enhanced sensitivity.
Results. S100B before the operation was 0.03 μg/L. At wound closure, S100B in patients of the off-pump and CPB groups reached a maximum level of 0.22 ± 0.07 and 2.4 ± 1.5 μg/L, respectively (p < 0.001). No strokes occurred. Patients without CPB receiving arterial and vein grafts released slightly more S100B (p < 0.05) than patients with only arterial grafting. In patients undergoing CPB, S100B increased slightly before aortic cannulation (p < 0.001), to the same level as the maximum reached for the non-CPB group.
Conclusions. Coronary artery bypass grafting with CPB caused a 10-fold greater increase in S100B than off-pump grafting. S100B release after off-pump sternotomy with vein grafting was slightly greater than in arterial grafting through a minithoracotomy. 相似文献
Resistance to activated protein C (APC) is among the coagulation disorders that have been implicated in retinal vein occlusion. However, since retinal vascular occlusions may be due to a combination of several mechanisms, the question of whether thrombophilic anomalies are pathogenic for this disorder remains controversial. In the current study, we investigated the prevalence of APC resistance in patients with retinal vein occlusion with reference to age and various cardiovascular risk factors. A cohort of 142 consecutive patients with retinal vein occlusion and a control group of 128 subjects matched for age, sex and several risk factors were screened for resistance to APC. Both cohorts were divided into two subgroups, according to the patient's age (< or =45 or >45 years) at the time of the retinal vein occlusion or a previous thromboembolic event. The proportion of individuals with resistance to APC was higher in the patient group (13 of 142; 9.1%) when compared to controls (6 of 128; 4.7%). Moreover, patient age < or =45 years by the time of the retinal vein occlusion or a previous thromboembolic event was significantly associated with a high prevalence of APC resistance (17%). By contrast, resistance to APC was present in 5 of 95 cases (5.3%) in the patient group >45 years and in 4 of 83 (4.8%) young controls. Our results indicate that APC resistance is highly prevalent in patients with retinal vein occlusion at age < or =45 years and/or with a history of thrombosis at this age. By contrast, the prevalence of APC resistance in patients who suffered a retinal vein occlusion when they were older than 45 years and had no history of thromboembolism appears to be similar to that seen in healthy control subjects or in the normal population. Selective screening may be helpful in identifying retinal vein occlusion patients with thrombophilic defects. 相似文献
BACKGROUND: Cystatin C is increasingly used as a glomerular filtration marker, but so far only a few companies produce most of the cystatin C reagents suited for turbidimetry or nephelometry use in clinical laboratories. METHODS: We studied different protocols for measuring cystatin C on an Architect ci8200 system using cystatin C reagents from Dako (Glostrup, Denmark). The results were compared with those obtained with Dade Behring reagents (Deerfield, IL, USA) on a BN ProSpec system. RESULTS: Differences in assay protocol on the same instrument with the Dako reagent yielded an up to 50% difference in glomerular filtration rate calculated from the cystatin C results when analyzing patient samples, but had no effect on the results for controls. There were also significant differences regarding linearity and kinetics between samples and controls/calibrators. CONCLUSIONS: The results indicate different reactivity of the Dako antibodies against calibrators and controls in comparison with patient samples, highlighting the importance of using controls and calibrators that do not differ from patient samples. 相似文献
Brain imaging based on functional magnetic resonance imaging (fMRI) provides a useful tool to examine neural networks and cerebral structures subserving visuospatial function. It allows not only the qualitative determination of which areas are active during task processing, but also estimates the quantitative contribution of involved brain regions to different aspects of spatial processing. In this study, we investigated in 10 healthy subjects how the amount of task (computational) demand in an angle discrimination task was related to neural activity as measured with event-related fMRI. Task demand, indicated by behavioral performance, was modulated by presenting clocks with different angular disparity and length of hands. Significant activations were found in the cortical network subserving the visual and visuospatial processing, including the right and left superior parietal lobules (SPL), striate visual areas, and sensorimotor areas. Both blood oxygenation level-dependent (BOLD) signal strength and spatial extent of activation in right as well as left SPL increased with task demand. By contrast, no significant correlation or a very weak correlation was found between the task demand and the BOLD signal as well as between task demand and spatial extent of activations in the striate visual areas and in the sensorimotor areas. These results support the hypothesis that increased computational demand requires more brain resources. The brain regions that are most specialized for the execution of the visuospatial task can be assessed by relating the imposed task demand to the functional activation measured. 相似文献