MRI-based volumetric measurement of the substantia innominata in amnestic MCI and mild AD

The substantia innominata (SI) contains the nucleus basalis of Meynert, which provides the major cholinergic innervation to the entire cortical mantel and the amygdala; degeneration of nucleus basalis neurons correlates with cognitive decline in Alzheimer's disease (AD). However, whether SI atrophy occurs in individuals with amnestic mild cognitive impairment (aMCI) has not been examined thoroughly in vivo. In the present study, we developed a new protocol to measure volumetric changes in the SI from magnetic resonance imaging (MRI) scans. Participants consisted of 27 elderly controls with no cognitive impairment (NCI); 33 individuals with aMCI; and 19 patients with mild AD. SI volumes were traced on three consecutive gapless 1 mm thick coronal slices. Results showed that SI volume was significantly reduced in the mild AD group compared to both NCI and aMCI participants; however, the NCI and aMCI groups did not differ from each other. Furthermore, a decrease in SI volume was related to impaired performance on declarative memory tasks even when attention was controlled.     

Verbal fluency performance in amnestic MCI and older adults with cognitive complaints

Verbal fluency tests are employed regularly during neuropsychological assessments of older adults, and deficits are a common finding in patients with Alzheimer's disease (AD). Little extant research, however, has investigated verbal fluency ability and subtypes in preclinical stages of neurodegenerative disease. We examined verbal fluency performance in 107 older adults with amnestic mild cognitive impairment (MCI, n = 37), cognitive complaints (CC, n = 37) despite intact neuropsychological functioning, and demographically matched healthy controls (HC, n = 33). Participants completed fluency tasks with letter, semantic category, and semantic switching constraints. Both phonemic and semantic fluency were statistically (but not clinically) reduced in amnestic MCI relative to cognitively intact older adults, indicating subtle changes in the quality of the semantic store and retrieval slowing. Investigation of the underlying constructs of verbal fluency yielded two factors: Switching (including switching and shifting tasks) and Production (including letter, category, and action naming tasks), and both factors discriminated MCI from HC albeit to different degrees. Correlational findings further suggested that all fluency tasks involved executive control to some degree, while those with an added executive component (i.e., switching and shifting) were less dependent on semantic knowledge. Overall, our findings highlight the importance of including multiple verbal fluency tests in assessment batteries targeting preclinical dementia populations and suggest that individual fluency tasks may tap specific cognitive processes.     

Multiple DTI index analysis in normal aging, amnestic MCI and AD. Relationship with neuropsychological performance

White matter (WM) damage has been reported in Alzheimer's Disease (AD) and Mild Cognitive Impairment (MCI) in diffusion tensor imaging (DTI) studies. It is, however, unknown how the investigation of multiple tensor indexes in the same patients, can differentiate them from normal aging or relate to patients cognition. Forty-six individuals (15 healthy, 16 a-MCI and 15 AD) were included. Voxel-based tract based spatial-statistics (TBSS) was used to obtain whole-brain maps of main WM bundles for fractional anisotropy (FA), radial diffusivity (DR), axial diffusivity (DA) and mean diffusivity (MD). FA reductions were evidenced among AD patients with posterior predominance. A-MCI patients displayed reduced mean FA in these critical regions, compared to healthy elders. MD increases were widespread in both groups of patients. Interestingly, a-MCI patients exhibited DR increases in overlapping areas of FA shrinkages in AD, whereas DA increases were only observed in AD. Gray matter atrophy explained most DTI differences, except those regarding MD in both groups as well as DR increases in posterior associative pathways among a-MCI cases. FA values were the only DTI measure significantly related to memory performance among patients. Present findings suggest that most DTI-derived changes in AD and a-MCI are largely secondary to gray matter atrophy. Notably however, specific DR signal increases in posterior parts of the inferior fronto-occipital and longitudinal fasciculi may reflect early WM compromise in preclinical dementia, which is independent of atrophy. Finally, global measures of integrity, particularly orientation coherence (FA) of diffusion, appear to be more closely related to the cognitive profile of our patients than indexes reflecting water movement parallel (DA) and perpendicular (DR) to the primary diffusion direction.     

Absent gender differences of hippocampal atrophy in amnestic type mild cognitive impairment

Hippocampus displayed progressively gender-associated damage in Alzheimer's disease. However, gender effects have been largely neglected in studies of amnestic type mild cognitive impairment (aMCI) patients who were believed to represent an early stage of this disease. The goal of this study was to use in vivo neuroimaging techniques to determine whether there were any evidences of gender differences in hippocampal atrophy in aMCI. A region of interest-based magnetic resonance imaging approach was used to compare hippocampal volume between aMCI patients (22 male, 17 female) and normal aging controls (12 male, 11 female). Independent of group, male hippocampal volumes were larger than female volumes and right hippocampal volumes were typically smaller than left volumes. Hippocampal volumes were significantly reduced in the clinical group but no gender differences were noted in terms of degree of atrophy present. However, female patients showed more impaired cognitive function than male patients despite this apparent equivalence in atrophy. The absence of a gender difference suggested that early neuropathological progression might be independent of gender. However, the data also suggested female aMCI patients had an increased vulnerability to cognitive impairment earlier in the illness course.     

Abnormal white matter independent of hippocampal atrophy in amnestic type mild cognitive impairment

Hippocampal atrophy is the key marker in the pathogenesis of Alzheimer's disease (AD), which is associated with white matter (WM) disruption. This type of WM disruption could partly explain AD-related pathology. However, relatively little attention has been directed toward WM disruption which may be independent of these fundamental gray matter (GM) changes in amnestic mild cognitive impairment (aMCI) which is associated with high risk of AD. To evaluate the differences of WM integrity between aMCI patients (N = 32) and healthy controls (N = 31), whole-brain voxel-based methods were applied to diffusion tensor imaging. To explore the possible independence of WM changes from GM loss, an index of hippocampal atrophy was used to partial out GM effects. aMCI patients showed WM disruption in frontal lobe, temporal lobe, internal capsule, cingulate gyrus and precuneus. The findings supported the evidence of independent patterns of degeneration in WM tracts which may co-act in the WM pathological process of aMCI patients. As aMCI is a putatively prodromal syndrome to AD, these data may assist with a better understanding of WM pathological change associated with the development of AD.     

Meta分析中标准化均差效应量的计算

背景：大多数情况下,在进行两组比较研究的Meta分析时,纳入Meta分析的各研究文献结果变量的操作差异较大,不同的研究结果间不能进行直接的比较,给Meta分析带来挑战。 目的：深入挖掘原始研究的信息方法,增强Meta分析结果的效能。 方法：根据原始研究提供的结局变量最常见的近10种情形介绍了标准化均差效应量的计算方法。 结果与结论：在进行两组比较研究Meta分析时需要综合分析各种可能情况,特别是当原始研究文献提供的信息与研究者已掌握的公式存在着距离时需要尽可能挖掘到所需要的信息,避免信息的流失。     

Diagnostic utility of the MCMI-I and MCMI-II with psychiatric outpatients

Research indicates that the Millon Clinical Multiaxial Inventory (MCMI-I) lacks diagnostic accuracy when compared to clinically generated DSM-III-R diagnoses. This shortcoming is most evident for the identification of psychotic disorders. The MCMI-II was designed to reflect more accurately the DSM-III-R diagnostic formulation, but its diagnostic efficacy has yet to be determined with clinical samples. In the present investigation, two consecutive samples of psychiatric patients who were attending an outpatient day treatment program were administered either the MCMI-I (N = 39) or the MCMI-II (N = 37). MCMI diagnoses were compared with clinician-generated DSM-III-R diagnoses. Relative to clinical judgment, both versions of the MCMI underestimated the incidence of psychotic disorders and overestimated the incidence of nonpsychotic disorders and personality disorders.     

Diagnostic utility of cell-block from bronchial washing in pulmonary neoplasms

In order to evaluate the usefulness of cell-block (CB) from bronchial washing in the diagnosis of pulmonary neoplasms, we examined cytological samples of 1,145 bronchoscopies; CBs could be prepared in 777 cases (67.9%) and 201 cases, positive or suspicious for malignancy, were selected for the study (173/201 smears: 86.1%; 174/201 CBs: 86.6%). CBs were positive in 12 cases while the corresponding smears were negative (10 cases) or suspicious (2 cases); 2 cases had suspicious CBs with negative smears. Thus, the use of CBs increased the positive diagnosis from 173 to 185 cases, for an increase of 6.5%. We can conclude that CB could be a routine, inexpensive method, helpful in pulmonary neoplasm's diagnosis; moreover, CB has the advantage of being an histologic specimen, often the only one, useful for other diagnostic procedures. Diagn Cytopathol 1996;15:191–192. © 1996 Wiley-Liss, Inc.     

Serum 24S-hydroxycholesterol and hippocampal size in middle-aged normal individuals

The present study assessed the association between serum 24S-hydroxycholesterol (24S-OH-Chol) and 27-hydroxycholesterol (27-OH-Chol) and hippocampal volumes in 69 middle-aged cognitively normal individuals. Results showed that subjects with high levels of oxysterols had significantly larger hippocampal volumes than subjects with low levels of oxysterols. Multiple regression analysis revealed that 24S-OH-Chol, but not 27-OH-Chol or cholesterol, was able to significantly predict hippocampal size. Future studies should elucidate whether high brain cholesterol metabolism in the middle age is protective against hippocampal atrophy and cognitive decline.     

Linking novelty seeking and harm avoidance personality traits to basal ganglia: volumetry and mean diffusivity

Novelty Seeking (NS) and Harm Avoidance (HA) temperamental traits are related to approaching or avoiding motivational circuits relying on the integrity and functionality of distributed brain areas implicated in arousal and action. The present study verified whether and how macro- and micro-structural variations of basal ganglia are correlated with scores obtained in the NS and HA temperamental scales of the Temperament and Character Inventory by Cloninger. To this aim, 125 healthy adults aged 18–67 years of both sexes completed the Temperament and Character Inventory and underwent a high-resolution T1-weighted magnetic resonance imaging and a diffusion tensor imaging using a 3T scanner. The scores obtained in the temperamental scales were associated with volumes, mean diffusivity and fractional anisotropy measures of basal ganglia of both hemispheres separately, by using linear regression analyses. We found increased bilateral caudate and pallidum volumes associated with higher NS scores, as well as increased mean diffusivity in the bilateral putamen associated with higher HA scores. Macro- and micro-structural variations of basal ganglia regions contribute to explain the biological variance associated with NS or HA personality phenotype. The present findings evidencing some brain-temperament relationships highlight the importance of obtaining macro- and micro-structural measures in relation to individual differences.     

Diagnostic utility of pleural fluid IFN-gamma in tuberculosis pleural effusion.

Pleural fluid interferon-gamma (IFN-gamma) levels are increased in patients with tuberculosis (TB) pleural effusion. Recent studies from the west have found that estimation of pleural fluid IFN-gamma levels is an excellent diagnostic strategy for these patients. The diagnostic utility of pleural effusion IFN-gamma level estimation has not been evaluated in patients from developing countries, however. This work was carried out to study the diagnostic utility of IFN-gamma level estimation in patients with TB pleural effusion and to define the best cutoff of IFN-gamma for diagnosis TB pleural effusion. We studied 101 patients with pleural effusion. Of these, 64 were found to have a TB etiology, established by means of various conventional modalities. Measurement of pleural fluid IFN-gamma levels was done by ELISA technique. The median value of pleural fluid IFN-gamma levels in patients with TB (1480 pg/ml, range 3-14,000 pg/ml) was significantly higher (p < 0.001) compared with the non-TB group (3 pg/ml, range 0-900 pg/ml). The receiver operator characteristic (ROC) curve for IFN-gamma showed an area under the curve (AUC) value of 0.954, and the best cutoff was computed to be 138 pg/ml. Using this cutoff for IFN-gamma levels in pleural fluid for the diagnosis of TB, sensitivity, specificity, negative predictive value, and positive predictive value were found to be 90.2%, 97.3%, 85.7%, and 98.3%, respectively. Estimation of IFN-gamma levels in pleural fluid is a useful diagnostic modality for TB pleural effusion. A cutoff of 138 pg/ml provides the best sensitivity and specificity for diagnosis of TB.