Reliability and Validity of the Chinese Version of Mild Behavioral Impairment Checklist in Mild Cognitive Impairment and Mild Alzheimer's Disease.

BACKGROUND: Mild behavioral impairment (MBI) has been proposed as an early manifestation of dementia. The Mild Behavioral Impairment Checklist (MBI-C) may help identify MBI in prodromal and preclinical dementia. OBJECTIVE: The study aimed to evaluate the reliability and validity of the Chinese version of MBI-C in mild cognitive impairment (MCI) and mild Alzheimer's disease (AD), and to explore the structure of the five factors of the MBI-C in Chinese culture. METHODS: Sixty dyads of MCI and mild AD (MCI, n = 33; mild AD, n = 35) were recruited. The informants completed the MBI-C and Neuropsychiatric Inventory Questionnaire (NPI-Q) and were interviewed for clinician rating of the NPI. The Cronbach's coefficient was used to measure the structural reliability of the MBI-C. The criterion-validity was evaluated with the correlation coefficient between the MBI-C and the total scores of NPI-Q and NPI. Exploratory factor analysis was conducted to investigate the structure of the MBI-C. RESULTS: The Cronbach's α coefficient was 0.895. The MBI-C total score was positively correlated with all five domains (r = 0.577∼0.840). The total score of MBI-C was significantly correlated with the total scores of NPI-Q (r = 0.714) and NPI (r = 0.749). Similarly, the five domain scores of MBI-C were significantly correlated with the factor and total scores of NPI-Q (r = 0.312∼0.673) and NPI (r = 0.389∼0.673). The components of each factor in Chinese version of MBI-C were slightly different from those of the a priori defined domains (χ2 = 1818.202, df = 496, p < 0.001). CONCLUSION: The Chinese version of MBI-C has good reliability and validity, and can be used to evaluate the psychological and behavioral changes in MCI and mild AD.

Tomitella biformata gen. nov., sp. nov., a new member of the suborder Corynebacterineae isolated from a permafrost ice wedge.

Gram-reaction-positive, aerobic, non-spore-forming, irregular rod-shaped bacteria, designated AHU1821(T) and AHU1820, were isolated from an ice wedge in the Fox permafrost tunnel, Alaska. The strains were psychrophilic, growing at -5 to 27°C. Phylogenetic analysis of the 16S rRNA and gyrB gene sequences indicated that the ice-wedge isolates formed a clade distinct from other mycolic-acid-containing bacteria within the suborder Corynebacterineae. The cell wall of strains AHU1821(T) and AHU1820 contained meso-diaminopimelic acid, arabinose and galactose, indicating chemotype IV. The muramic acids in the peptidoglycan were glycolated. The predominant menaquinone was MK-9(H(2)). The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides and an unidentified glycolipid. The major fatty acids were hexadecenoic acid (C(16 : 1)), hexadecanoic acid (C(16 : 0)), octadecenoic acid (C(18 : 1)) and tetradecanoic acid (C(14 : 0)). Tuberculostearic acid was present in relatively small amounts (1 %). Strains AHU1821(T) and AHU1820 contained mycolic acids with 42-52 carbons. The DNA G+C content of the two strains was 69.3-71.6 mol% (T(m)). 16S rRNA, rpoB and recA gene sequences were identical between strains AHU1821(T) and AHU1820 and those of the gyrB gene showed 99.9 % similarity. Based on phylogenetic and phenotypic evidence, strains AHU1821(T) and AHU1820 represent a single novel species of a novel genus, for which the name Tomitella biformata gen. nov., sp. nov. is proposed. The type strain of Tomitella biformata is AHU1821(T) (=DSM 45403(T) =NBRC 106253(T)).

Glaciibacter superstes gen. nov., sp. nov., a novel member of the family Microbacteriaceae isolated from a permafrost ice wedge.

Gram-positive, aerobic, non-spore-forming, irregular rod-shaped bacteria, designated strains AHU1791(T) and AHU1810, were isolated from a permafrost ice wedge in Alaska. Cells were motile by means of a polar flagellum. The strains were psychrophilic, growing at -5 to 25 degrees C. Phylogenetic analysis of 16S rRNA gene sequences indicated that the ice-wedge isolates formed a clade distinct from other genera affiliated with the family Microbacteriaceae. The novel strains showed highest levels of 16S rRNA gene sequence similarity with members of the genera Agreia and Subtercola (95.6-95.9 %). The level of 16S rRNA gene sequence similarity between strains AHU1791(T) and AHU1810 was 99.8 %. The cell-wall peptidoglycan type of the two strains was B2gamma, containing 2,4-diaminobutyric acid as the diagnostic amino acid. The predominant menaquinones were MK-12 and MK-13 (strain AHU1791(T)) and MK-11 and MK-12 (strain AHU1810). The major fatty acids of the two strains were 12-methyl tetradecanoic acid (anteiso-C(15 : 0)), 14-methyl hexadecanoic acid (anteiso-C(17 : 0)), 14-methyl pentadecanoic acid (iso-C(16 : 0)) and 13-methyl tetradecanoic acid (iso-C(15 : 0)). The DNA G+C contents of strains AHU1791(T) and AHU1810 were approximately 65 mol%. These phenotypic characteristics differentiated the ice-wedge strains from their closest phylogenetic neighbours, namely Subtercola boreus and the two recognized species of the genus Agreia. The sequences of the housekeeping genes coding for DNA gyrase subunit B (gyrB), RNA polymerase subunit B (rpoB) and recombinase A (recA) were almost identical between strains AHU1791(T) and AHU1810. Although the predominant menaquinones found in strains AHU1791(T) and AHU1810 were different, no other distinct differences were found with regard to other phenotypic and genotypic characteristics, indicating that the two strains were members of the same species. Accordingly, strains AHU1791(T) and AHU1810 are considered to represent a single novel species of a new genus, for which the name Glaciibacter superstes gen. nov., sp. nov. is proposed. The type strain of Glaciibacter superstes is AHU1791(T) (=DSM 21135(T) =NBRC 104264(T)).

Phylogenetic analysis of bacteria preserved in a permafrost ice wedge for 25,000 years.

Phylogenetic analysis of bacteria preserved within an ice wedge from the Fox permafrost tunnel was undertaken by cultivation and molecular techniques. The radiocarbon age of the ice wedge was determined. Our results suggest that the bacteria in the ice wedge adapted to the frozen conditions have survived for 25,000 years.