Grafting strategy to develop single site titanium on an amorphous silica surface

Titanium/silica systems were prepared by grafting a titanium alkoxide (titanium isopropoxide and titanium (triethanolaminate) isopropoxide) precursor onto amorphous silica. The grafting process, which consisted of the hydrolysis of the Ti precursor by the hydroxyl groups on the silica surface, yielded samples containing Ti-loadings of 1-1.6 wt %. The as synthesized and calcined TiO(2)-SiO(2) samples were characterized by UV-vis, FTIR, XPS, and XANES spectroscopic techniques. These systems were tested in the liquid-phase epoxidation of oct-1-ene with hydrogen peroxide reaction. Spectroscopic data indicated that titanium anchoring takes place by reaction between the alkoxide precursor and surface OH groups of the silica substrate. The nature of surface titanium species generated by chemical grafting depends largely on the titanium precursor employed. Thus, the titanium isopropoxide precursor yields tetrahedrally coordinated polymeric titanium species, which give rise to a low-efficiency catalyst. However, if an atrane precursor (titanium (triethanolaminate) isopropoxide) is employed, isolated titanium species are obtained. The fact that these species remain isolated even after calcination is due to the protective effect of the triethanolaminate ligand that avoids titanium polymerization. These differences in the titanium environment have a pivotal role in the performance of these systems in the epoxidation of alkenes with hydrogen peroxide.

Silica-polypyrrole core-shell nanocomposites as active materials for dielectrophoretic displays

A direct route to silica-polypyrrole core-shell nanoparticles has been used to design new nanocomposites, in which the conducting part is then wrapped by an external silica shell in order to have finally neutral nanoparticles. The nanocomposites are characterized by TEM, spectroscopy, electrochemistry and thermal gravimetric analysis, demonstrating that the external silica shell actually insulates the conjugated polymer from the outer medium. Finally the electrorheological properties of these nanocomposites are checked in a dielectrophoretic device in which the motion of the particles induced by an external electric field can be used to monitor a switch of the light transmission properties.

Measuring mania metabolites: a longitudinal proton spectroscopy study of hypomania

OBJECTIVE

Using single-voxel proton spectroscopy we aimed to investigate changes in metabolite levels in key brain regions during hypomania and euthymia in patients with bipolar disorder (BD).

METHOD

Nine patients with a diagnosis of BD and nine age, sex, education, and handedness-matched comparison subjects underwent magnetic resonance proton spectroscopy (H(1)-MRS) using a 1.5 T magnet. Patients were assessed whilst hypomanic and euthymic. Metabolite (N-acetyl asparTate, NAA; myo-inositol, mI; choline, Cho) levels in the basal ganglia (BG), anterior cingulate cortex (AC), and frontal cortex (FC) were compared both between groups and within the patient group.

RESULTS

Multivariate analysis revealed significant complex relationships between metabolite levels and brain regions with significant differences observed both between bipolar patients (hypomanic and euthymic) and controls, and across the two mood states. Hypomanic patients had lower mean metabolite levels when averaged across the AC and FC regions, compared with the controls. They also had a smaller difference in mean metabolite levels between the BG and FC than the control group. Euthymic patients were also found to have a smaller difference in the level of NAA between the BG and AC than the control group.

CONCLUSION

This exploratory study of BD demonstrates significant differences in metabolite levels that vary both with respect to brain region and mood state. Not withstanding the confounding effects of medication and the limitation of small sample size the findings are important as they demonstrate that a longitudinal approach is a useful design especially in the context of a long-term phasic illness.

Hippocampal size and dementia in stroke patients: the Sydney stroke study

BACKGROUND

Hippocampal atrophy is an early feature of Alzheimer's disease (AD) but it has also been reported in vascular dementia (VaD). It is uncertain whether hippocampal size can help differentiate the two disorders.

METHODS

We assessed 90 stroke/TIA patients 3-6 months after the event, and 75 control subjects, with neuropsychological tests, medical and psychiatric examination and brain MRI scans. A diagnosis of VaD, vascular mild cognitive impairment (VaMCI) or no cognitive impairment (NCI) was reached by consensus on agreed criteria. T1-weighted MRI was used to obtain total intracranial volume (TICV), gray and white matter volume, CSF volume, hippocampus and amygdala volumes, and T2-weighted scans for white matter hyperintensity (WMH) ratings.

RESULTS

Stroke/TIA patients had more white matter hyperintensities (WMHs), larger ventricle-to-brain ratios and smaller amygdalae than controls, but hippocampus size and gray and white matter volumes were not different. WMHs and amygdala but not hippocampal volume distinguished stroke/TIA patients with VaD and VaMCI and without NCI and amygdala volumes. Right hippocampus volume significantly correlated with new visual learning.

CONCLUSIONS

Stroke/TIA patients and patients with post-stroke VaMCI or mild VaD do not have hippocampal atrophy. The amygdala is smaller in stroke/TIA patients, especially in those with cognitive impairment, and this may be accounted for by white matter lesions. The hippocampus volume relates to episodic memory, especially right hippocampus and new visual learning. A longitudinal study of these subjects will determine whether hippocampal atrophy is a late development in VaD.

Pulmonary function, cognitive impairment and brain atrophy in a middle-aged community sample

OBJECTIVE

To determine the relationship of lung function to brain anatomical parameters and cognitive function and to examine the mediating factors for any relationships.

METHODS

A random sub-sample of 469 persons (men = 252) aged 60-64 years from a larger community sample underwent brain magnetic resonance imaging scans and pulmonary function tests (forced vital capacity, FVC, forced expiratory volume in the first second, FEV(1)). Subjects were assessed for global cognitive function, episodic memory, working memory, information processing speed, fine motor dexterity and grip strength. The magnetic resonance imaging scans were analysed for overall brain atrophy, subcortical atrophy (ventricle-to-brain ratio, VBR), hippocampal volume, and white matter hyperintensity (WMH) volume.

RESULTS

FEV(1) had a significant negative correlation with overall brain atrophy and VBR in men. The FEV(1)/FVC ratio had a significant correlation with WMHs in both men and women. In regression models that controlled for sex, age, height, level of activity, smoking, chronic respiratory disease and education, FEV(1) and FVC were significant predictors of VBR but no other structural brain measure. Pulmonary function was also significantly related to information processing speed and fine motor dexterity. Male subjects with chronic respiratory disease had more deep WMHs. Path analyses to examine if structural measures mediated between lung function and cognition, and whether markers of inflammation and oxidative stress or cortisol mediated between lung function and brain measures were negative.

CONCLUSIONS

Decreased lung function is related to poorer cognitive function and increased subcortical atrophy in mid-adult life. Presence of chronic respiratory disease may be related to deep WMHs in men.

Clinical determinants of dementia and mild cognitive impairment following ischaemic stroke: the Sydney Stroke Study

BACKGROUND

Dementia following stroke is common but its determinants are still incompletely understood.

METHODS

In the Sydney Stroke Study, we performed detailed neuropsychological and medical-psychiatric assessments on 169 patients aged 50-85 years, 3-6 months after a stroke, and 103 controls with a majority of both groups undergoing MRI brain scans. Stroke subjects were diagnosed as having vascular mild cognitive impairment (VaMCI) or vascular dementia (VaD) or no cognitive impairment by consensus. Demographic, functional, cerebrovascular risk factors and neuroimaging parameters were examined as determinants of dementia using planned logistic regression.

RESULTS

21.3% of subjects were diagnosed with VaD, with one case in those aged 50-59 years, 24% in those aged 60-69 years and 23% in those 70-79 years. There was no difference by sex. The prevalence of VaMCI was 36.7%. VaD subjects had lower premorbid intellectual functioning and had 0.9 years less education than controls. The VaD and VaMCI groups did not differ from the no cognitive impairment group on any specific cerebrovascular risk factor, however overall those with impairment had a greater number of risk factors. They did not differ consistently on depression severity, homocysteine levels and neuroimaging parameters (atrophy, infarct volume and number of infarcts) except for an excess of white matter lesions on MRI and greater number of infarcts in the VaD and VaMCI groups. On a series of logistic regression analyses, stroke volume and premorbid function were significant determinants of cognitive impairment in stroke patients.

CONCLUSION

Post-stroke dementia and MCI are common, especially in older individuals. Cerebrovascular risk factors are not independent risk factors for VaD, but stroke volume is a significant determinant of dementia. Premorbid functioning is a determinant of post- stroke impairment.

A correlative study of NF-kappaB activity and cytokines expression in human chronic nasal sinusitis

A growing body of literature suggests that cytokines play an important part in the pathogenesis of chronic nasal sinusitis. However, the mechanism by which the expression of cytokines in chronic nasal sinusitis is upregulated has not been well documented. The present study investigated the role of nuclear factor-kappa B (NF-kappaB) activation in upregulating the expression of interleukin-5, -6 and -8 (IL-5, IL-6 and IL-8). We titrated the levels of IL-5, IL-6 and IL-8 in nasal mucosa in 52 cases of chronic nasal sinusitis and 12 normal subjects using enzyme-linked immunosorbent assay. According to whether allergic rhinitis was associated or not, we subdivided the patients into the AR group (with allergic rhinitis) and the NAR group (without allergic rhinitis). Semi-quantitative reverse transcription-polymerase chain reaction and immunohistochemical staining were used to evaluate expression and activation of NF-kappaB P50 and P65 subunits in nasal mucosa. The correlation between activities of P50 and P65 and cytokines expression was analysed. Our results showed that IL-5, IL-6 and IL-8 in both the AR and NAR groups were strikingly elevated in comparison with the control group (all p < 0.01 for AR group; p < 0.05, 0.05, 0.01, respectively, for NAR group); and they were even higher in the AR group than those in the NAR group (p < 0.01, 0.05, 0.01, respectively). P50 and P65 mRNA levels in both AR and NAR groups were markedly greater than those in the control group (all p < 0.01); and the AR group had further higher levels as compared with the NAR group (both p < 0.05). Immunohistochemical study revealed that nucleus-positive rates of P50 and P65 in both AR and NAR groups were significantly higher than those of the control group (all p < 0.01), and they were much greater in the AR group in comparison with the NAR group (all p < 0.01). Pearson correlation analysis demonstrated that P50 and P65 nucleus-positive rates were closely correlated with IL-6 and IL-8 levels, but not IL-5, with a correlation coefficient of 0.49 for P50 and IL-6, 0.54 for P50 and IL-8, 0.61 for P65 and IL-6, and 0.66 for P65 and IL-8 (all p < 0.01). In conclusion, upregulated expression and activation of NF-kappaB P50 and P65 might be one of the mechanisms for induction of IL-6 and IL-8 expression in chronic nasal sinusitis. Association of allergic rhinitis with chronic nasal sinusitis further enhanced NF-kappaB activity, and subsequently lead to even stronger expression of IL-6 and IL-8. IL-5 expression appeared to be independent of NF-kappaB pathway in chronic nasal sinusitis.

CYP19A1 genetic polymorphisms may be associated with obesity-related phenotypes in Chinese women

OBJECTIVE

To examine the relationship between genetic polymorphisms of the CYP19A1 gene and obesity-related phenotypes, body mass index (BMI) and waist-to-hip ratio (WHR).

SUBJECTS

In total, 1241 Chinese women, who were recruited as community controls for a population-based case-control study of breast cancer.

METHODS

Nineteen haplotype tagging single nucleotide polymorphisms (htSNPs) in four haplotype blocks were genotyped.

RESULTS

Significant associations were observed for WHR at three SNPs that are located in haplotype block 1, including rs2445765, rs1004984 and rs1902584 (P=0.05, 0.04 and 0.01, respectively). Women, particularly premenopausal women, who carried the minor allele at any of these SNPs, had higher WHR than those without it. Of these three SNPs, the strongest association was observed at rs1902584, which is the closest to Promoter I.4, the major promoter for adipose tissue. Haplotype analyses indicated an association between the haplotype TCCAT in block 1 and WHR with a P-value of 0.02.

CONCLUSION

These results suggested that CYP19A1 genetic polymorphisms may be associated with the risk of obesity among Chinese women, especially among premenopausal women. The CYP19A1 protein (aromatase) plays a critical role in estrogen biosynthesis and thus affects body fat distribution and regulation.

1H MRS in stroke patients with and without cognitive impairment

The pathophysiological basis of cognitive impairment in patients with cerebrovascular disease (CVD) is not well understood, particularly in relation to the role of non-infarction ischemic change and associated Alzheimer-type pathology. We used single voxel 1H MRS to determine the differences in brain neurometabolites in non-infarcted frontal white matter and occipito-parietal gray matter of 48 stroke patients with or without cognitive impairment and 60 elderly controls. The results showed that there were no significant neurometabolite differences between the stroke cohort and healthy elderly controls, but there was a difference in NAA/H2O between the stroke patients that had cognitive impairment (vascular dementia (VaD) and vascular cognitive impairment (VCI)) compared with those patients with no impairment. This was significant in the occipito-parietal gray matter, but not in the frontal white matter, although the results were in the same direction for the latter. This suggests that cognitive impairment in stroke patients may be related to cortical neuronal dysfunction rather than purely subcortical change. Moreover, cortical regions not obviously infarcted may have dysfunctional neurons, the pathophysiological basis for which needs further study.

White matter hyperintensities are related to physical disability and poor motor function

OBJECTIVE

To determine the impact of white matter hyperintensities (WMHs) on physical health and cognitive function in 60-64 year old individuals residing in the community.

METHODS

A subsample of 478 persons aged 60-64 from a larger community sample underwent brain magnetic resonance imaging (MRI) scans. WMHs on T2 weighted FLAIR (fluid attenuated inversion recovery) MRI scans were assessed using an automated procedure. Subjects were assessed for global cognitive function, episodic memory, working memory (digit span), information processing speed (Symbol Digit Modalities Test; SDMT), fine motor dexterity (Purdue Pegboard), and grip strength, and completed the Physical Component Summary of the Short Form Health Survey (SF-12). Regression analyses were used to examine the effect of WMHs on physical and cognitive function.

RESULTS

Deep and periventricular WMHs were present in all subjects, with women having slightly more lesions than men. WMHs were significantly associated with poorer reported physical health on the SF-12 scale, after adjusting for depression, cognitive function, and brain atrophy. WMHs were also related to lower scores on the Purdue Pegboard test, grip strength, choice reaction time, and SDMT, but not on tests of episodic memory, working memory, general intellectual function, and global cognitive function. On regression analyses, the Purdue Pegboard test and grip strength were related to physical disability.

CONCLUSION

WMHs are common, albeit mild, in middle adult life. They are associated with physical disability, possibly through reduced speed, fine motor coordination, and muscular strength. They are also related to slowed information processing speed but not other cognitive functions.

Memory complaints in a community sample aged 60-64 years: associations with cognitive functioning, psychiatric symptoms, medical conditions, APOE genotype, hippocampus and amygdala volumes, and white-matter hyperintensities

BACKGROUND

Previous research has found that depression is a major cause of memory complaints. However, there is evidence that memory complaints also weakly predict cognitive decline and dementia. The present study examined a range of possible determinants of memory complaints, covering psychiatric and personality factors, medical history, cognitive test performance, and biological risk factors for dementia (APOE genotype, hippocampus and amygdala volumes, and white-matter hyperintensities).

METHOD

A community survey was carried out with 2546 persons aged 60-64 years living in Canberra and Queanbeyan, Australia. Participants were asked about memory problems which interfered with daily life and whether medical help had been sought. A randomly selected subsample of 476 persons was given a brain MRI scan.

RESULTS

Participants with memory complaints were found to have poorer memory test performance, more depression and anxiety symptoms, have higher scores on personality traits involving negative affect, and to have worse physical health. Multivariate analyses showed that measures of cognitive performance did not make a unique contribution to the prediction of memory complaints above that of the other categories of predictors. Those with memory complaints did not differ on any of the biological risk factors for dementia.

CONCLUSION

In a community sample aged 60-64 years, memory complaints were most closely related to psychiatric symptoms, personality characteristics and poor physical health. There was no evidence of brain changes indicating early dementia.

The neuropsychological profile of vascular cognitive impairment in stroke and TIA patients

OBJECTIVE

To characterize the neuropsychological profile of vascular cognitive impairment (VCI) and vascular dementia (VaD).

METHODS

The authors examined 170 patients with stroke or TIA at 3 to 6 months after the vascular event, and 96 age-matched healthy controls, with detailed neuropsychological and medical-psychiatric assessments, with a majority (66.7%) undergoing MRI brain scans. The subjects were diagnosed as having VaD, VCI, or no cognitive impairment by consensus. The neuropsychological tests were classified into cognitive domains, and composite z-scores adjusted for age and education.

RESULTS

VaD subjects had disturbance in all cognitive domains, with verbal memory, especially retention, being less affected. VCI subjects had similar but less severe disturbance. The domains that best discriminated cognitively impaired from unimpaired patients were abstraction, mental flexibility, information processing speed, and working memory. Cognitive impairment had a significant correlation with deep white matter hyperintensities, but not with volume and number of infarctions, even though the VaD subjects had larger infarct volumes than VCI subjects. The MRI variables did not provide additional discrimination between subgroups.

CONCLUSIONS

The cognitive deficits in VaD and VCI are characterized by disturbance of frontal functions, with less verbal memory impairment. VaD and VCI differ in severity but not pattern of disturbance. The brain lesions that best account for these deficits are noninfarct subcortical white matter and gray matter changes due to ischemia. The picture of VaD/VCI presented shows subcortical deficits embellished by cognitive deficits from cortical infarctions.

Validity and reproducibility of the food frequency questionnaire used in the Shanghai Women's Health Study

To evaluate the validity and reliability of the food frequency questionnaire (FFQ) used in the Shanghai Women's Health Study (SWHS), 200 SWHS participants were recruited for a dietary calibration study. Study participants completed an FFQ at baseline and 24-h dietary recalls (24-HDR) twice per month consecutively for 12 months. At the end of the study, a second FFQ was administered. Of the 200 study participants, 196 completed 24 or more days of 24-h dietary recalls, 191 completed two FFQs from whom the results of this report were based. The FFQ included the foods that accounted for 86% of the foods recorded in the 24-HDR surveys. Validity of the FFQ was evaluated by comparing intake levels of major nutrients and foods obtained from the second FFQ with those derived from the multiple 24-HDR. The median intake for major nutrients, rice, poultry and meat derived from the second FFQ and the 24-HDR was similar, with the differences ranging from 1.3 to 12.1%. The FFQ tended to overestimate the intake level of total vegetables and total fruits, and the differences were explained mainly by over-reporting seasonal vegetables and fruits consumption in the FFQ. Nutrient and food intake assessed by the FFQ and the multiple 24-HDR correlated very well, with the correlation coefficients being 0.59-0.66 for macronutrients, 0.41-0.59 for micronutrients, and 0.41-0.66 for major food groups. The reliability of the FFQ was assessed by comparing the correlation and median intake of nutrients and food groups obtained from the two FFQs that were administered approximately 2 y apart. The median intake levels for selected nutrients and food groups derived from the two FFQs were similar with differences below 10%. At the individual level, the intake levels of these dietary variables obtained from two FFQs also correlated well. When nutrient and food group intakes were categorized into quartiles, FFQ and 24-HDR produced exact agreement rates between 33 and 50%. Misclassification to adjacent quartile was common, ranging from 34-48%, while misclassification to an extreme quartile was rare (1-6%). These data indicate that the SWHS FFQ can reliably and accurately measure usual intake of major nutrients and food groups among women in Shanghai.

Sociodemographic, behavioral, and reproductive factors associated with weight gain in Chinese women

OBJECTIVE

To examine whether certain sociodemographic, behavioral, and reproductive factors are associated with an increased weight gain in Chinese women.

DESIGN

Baseline survey data, including recalled past weight and measured current weight, from an ongoing prospective cohort study conducted in Shanghai, China.

SUBJECTS

The analytical sample included 75 039 nonpregnant women aged 40-70 y.

MEASUREMENTS

Statistical associations between certain sociodemographic, behavioral, and reproductive factors and weight gain were evaluated using multiple linear and logistic regression models.

RESULTS

Weight gain and waist-to-hip ratio (WHR) increased with age among pre- and postmenopausal women before age 55 y. Weight gain declined but WHR continued rising as aging among postmenopausal women over age 55 y. Lower education levels, more parity and earlier age at the first birth, and earlier menarcheal age were associated with a higher long-term weight gain and current body weight.

CONCLUSION

Age, education levels, parity, age at the first live birth, and menarcheal age were associated with long-term weight gain in Chinese women. However, these results concerning weight gain are based on recalled past weight and should be interpreted with caution. Further studies are needed to clarify the association of weight gain with lifestyle factors suggested by this study.

High (15 Hz) and low (1 Hz) frequency transcranial magnetic stimulation have different acute effects on regional cerebral blood flow in depressed patients

BACKGROUND

High and low frequency repetititve transcranial magnetic stimulation (rTMS) are both effective in treating depression but have contrary effects on motor cortical activity. This study aimed to understand further the mechanisms of action of high and low frequency rTMS by examining their acute effects on regional cerebral blood flow (rCBF) in depressed patients.

METHOD

Eighteen depressed subjects underwent brain single photon emission computerized tomography (SPECT) scanning using split-dose 99mTc-HMPAO, and were examined during sham and active rTMS to the left prefrontal cortex, at 15 Hz or 1 Hz (N=9 each). Relative rCBF changes were examined by statistical parametric mapping and by regions of interest analysis.

RESULTS

High (15 Hz) frequency rTMS resulted in relative rCBF increases in the inferior frontal cortices, right dorsomedial frontal cortex, posterior cingulate and parahippocampus. Decreases occurred in the right orbital cortex and subcallosal gyrus, and left uncus. Low (1 Hz) frequency rTMS led to increased relative rCBF in the right anterior cingulate, bilateral parietal cortices and insula and left cerebellum. High frequency rTMS led to an overall increase, whereas low frequency rTMS produced a slight decrease, in the mean relative rCBF in the left dorsolateral prefrontal cortex.

CONCLUSIONS

High (15 Hz) and low (1 Hz) frequency rTMS led to different frontal and remote relative rCBF changes, which suggests different neurophysiological and possibly neuropsychiatric consequences of a change in frequency of rTMS.

[Studies on the continuous culture and the growth of Entamoeba gingivalis]

AIM

To establish a method for continuous culture of Entamoeba gingivalis(E. g.).

METHODS

The culture conditions of E. g. were compared by observing its size and survival time at room temperature.

RESULTS

The growth of E. g. under different culture conditions including culture medium, temperature and pH were compared. The accompanying bacteria associate with E. g. FJ4 were isolated and identified. The average size of E. g. was 13.19 microns-49.93 microns x 9.88 microns-30.74 microns. The optimal culture conditions of E. g. were: modified LES or YES medium, pH 6.4-6.7, nutritional liquids such as Locke's solution or yolk liquid with 20% bovine serum, penicillin, streptomycin and rice flour at 35 degrees C. Reproduction of E. g. peaked at the fourth day of incubation, and the survival time of E. g. was 120 h-168 h.

CONCLUSION

E. g. could be continuously cultured in modified LES or YES medium by inoculating once every four days.