Secondary thalamic atrophy related to brain infarction may contribute to post-stroke cognitive impairment

BACKGROUND AND PURPOSE

The thalamus is a key brain hub that is globally connected to many cortical regions. Previous work highlights thalamic contributions to multiple cognitive functions, but few studies have measured thalamic volume changes or cognitive correlates. This study investigates associations between thalamic volumes and post-stroke cognitive function.

METHODS

Participants with non-thalamic brain infarcts (3-42 months) underwent MRI and cognitive testing. Focal infarcts and thalami were traced manually. In cases with bilateral infarcts, the side of the primary infarct volume defined the hemisphere involved. Brain parcellation and volumetrics were extracted using a standardized and previously validated neuroimaging pipeline. Age and gender-matched healthy controls provided normal comparative thalamic volumes. Thalamic atrophy was considered when the volume exceeded 2 standard deviations greater than the controls.

RESULTS

Thalamic volumes ipsilateral to the infarct in stroke patients (n=55) were smaller than left (4.4 ± 1.4 vs. 5.4 ± 0.5 cc, p < 0.001) and right (4.4 ± 1.4 vs. 5.5 ± 0.6 cc, p < 0.001) thalamic volumes in the controls. After controlling for head-size and global brain atrophy, infarct volume independently correlated with ipsilateral thalamic volume (β= -0.069, p=0.024). Left thalamic atrophy correlated significantly with poorer cognitive performance (β = 4.177, p = 0.008), after controlling for demographics and infarct volumes.

CONCLUSIONS

Our results suggest that the remote effect of infarction on ipsilateral thalamic volume is associated with global post-stroke cognitive impairment.

Abstract P359: Secondary Thalamic Atrophy Related to Brain Infarction is Associated With Post-Stroke Cognitive Impairment

Background: The thalamus is globally connected to many brain regions. Previous work highlights thalamic contributions to multiple cognitive functions, but few studies have measured thalamic volume changes or explored correlates of such changes with post-stroke cognition. Hence this study investigates possible associations of thalamic volumes with post-stroke cognitive functions.

Methods: Participants with brain infarcts (6-42 months) underwent volumetric brain MRI and cognitive testing, including the Montreal Cognitive Assessment (MoCA). Focal Brain infarcts and thalami were traced manually. If the patient had bilateral infarcts, the side of the primary infarct volume defined the hemisphere involved. Brain parcellation and volumetrics used our comprehensive semi-automatic brain region and vascular lesion extraction pipeline (Ramirez, Neuroimage, 2011). MRI in 24 age and gender-matched healthy people provided normal comparative thalamic volumes. Thalamic atrophy was defined by percent thalamic volume loss in the stroke hemisphere compared to the other side. Spearman correlation assessed relationships between thalamic and infarct volumes and MoCA scores. Logistic regression analysis assessed whether thalamic atrophy correlated with MoCA score.

Results: Thalami volumes ipsilateral to the infarct in stroke patients (n=55) were smaller than left (4.4 ± 1.4 vs. 5.4 ± 0.8 cc, p = 0.012) and right (4.4 ± 1.4 vs. 5.3 ± 0.7 cc, p = 0.024) thalamic volumes in the controls. Thalamic volumes were inversely correlated with ipsilateral infarct volumes (r = -0.384, p = 0.004). After controlling for head-size and brain atrophy, infarct volume independently correlated with ipsilateral thalamic volume s (β= -0.068, P=0.026), and only frontal infarcts (β = 2.300, p = 0.021) independently contributed to > 15% ipsilateral thalamic atrophy. Left thalamic atrophy of > 10% correlated significantly with poorer MoCA performance (β = 3.139, p = 0.023), after controlling for demographics and infarct volumes.

Conclusions: Our results suggest that remote effects of infarction on ipsilateral thalamic volume, presumably related to disrupted thalamic-cortical interconnectivity, is associated with a commonly used metric of post-stroke cognitive impairment.

Low economic growth and health inequalities in a rich country: 27-year Japanese time series

This presentation extends the public health theme in relation to Sustainable Development Goal #8, focusing on the health inequality trend in Japan. it is important to understand whether low economic growth is compatible with a low level of health inequalities. Unlike the UK and USA, life expectancy in Japan continued to improve despite a stagnant economy.

Ten triennial waves of a nationally representative survey in Japan, 1986-2013 (n = 731,647) were used. Slope and Relative Indices of Inequality (SII and RII respectively) in relation to net household income and self-rated good health were calculated. Analyses were stratified by sex and age, for children, working-age adults, younger old and older old, given age differences in relation to labour market. Time trends of SII and RII were tested during the period of economic stagnation 1992-2013.

In all age groups, prevalence of good health declined slightly from its peak in 1995 but increased after 2007. In 1992 among children, working-age adults and younger old, health inequality based on SII was small, about 10% lower prevalence of good health in those with lowest compared to highest income. Among working-age adults, time trends of health inequalities based on SII narrowed from 1992 and then widened after 2002 (quadratic trends in men and women p &lt; 0.05), resulting in the magnitude of health inequality returning to its level at the beginning of economic stagnation in 1992 but not exceeding it. Time trends in relative inequality (RII) were qualitatively similar to those in absolute inequality (SII).

The long-term low-growth Japanese economy appears compatible with maintaining and improving population health and holding health inequalities at current levels. This evidence is of great significance for sustainable development and the health of current and future generations.

PCP4/PEP19 upregulates aromatase gene expression via CYP19A1 promoter I.1 in human breast cancer SK-BR-3 cells

The Purkinje cell protein 4/peptide 19 (PCP4/PEP19) is a novel breast cancer cell expressing peptide, originally found in the neural cells as an anti-apoptotic factor, could inhibit cell apoptosis and enhance cell migration and invasion in human breast cancer cell lines. The expression of PCP4/PEP19 is induced by estrogens in estrogen receptor-positive (ER⁺) MCF-7 cells but also highly expressed in ER^- SK-BR-3 cells. In this study, we investigated the effects of PCP4/PEP19 on aromatase gene expression in MCF-7 and SK-BR-3 human breast cancer cells. In SK-BR-3 cells but not in MCF-7 cells, PCP4/PEP19 knockdown by siRNA silencing decreased the aromatase expression in gene transcriptional level. When PCP4/PEP19 was overexpressed by CMV promoter-driven PCP4/PEP19 expressing plasmid transfection, aromatase gene transcription increased in SK-BR-3 cells. This aromatase gene transcription is mainly mediated through promoter region PI.1, which is usually active in the placental tissue but not in the breast cancer tissue. These results indicate a new function of PCP4/PEP19 that would enhance aromatase gene upregulation to supply estrogens in heterogeneous cancer microenvironment.

The effects of music-supported therapy on motor, cognitive, and psychosocial functions in chronic stroke

Neuroplasticity accompanying learning is a key mediator of stroke rehabilitation. Training in playing music in healthy populations and patients with movement disorders requires resources within motor, sensory, cognitive, and affective systems, and coordination among these systems. We investigated effects of music-supported therapy (MST) in chronic stroke on motor, cognitive, and psychosocial functions compared to conventional physical training (GRASP). Twenty-eight adults with unilateral arm and hand impairment were randomly assigned to MST (n = 14) and GRASP (n = 14) and received 30 h of training over a 10-week period. The assessment was conducted at four time points: before intervention, after 5 weeks, after 10 weeks, and 3 months after training completion. As for two of our three primary outcome measures concerning motor function, all patients slightly improved in Chedoke-McMaster Stroke Assessment hand score, while the time to complete Action Research Arm Test became shorter in the MST group. The third primary outcome measure for well-being, Stroke Impact Scale, was improved for emotion and social communication earlier in MST and coincided with the improved executive function for task switching and music rhythm perception. The results confirmed previous findings and expanded the potential usage of MST for enhancing quality of life in community-dwelling chronic-stage survivors.

Blood Pressure Variability in Acute Ischemic Stroke: Influence of Infarct Location in the Insular Cortex

Background: The aim of this study was to elucidate the influence of insular infarction on blood pressure (BP) variability and outcomes according to the region of the insular cortex affected. Methods: A total of 90 patients diagnosed with acute unilateral ischemic stroke were registered. The BP variability was calculated over 24 h after admission (hyperacute) and for 2–3 days after admission (acute). Patients were classified into groups of right and left, and then right anterior, right posterior, left anterior, and left posterior insular infarction. Results: Patients with insular infarction showed a significantly larger infarct volume, higher modified Rankin scale scores, and lower SD and coefficient of variation (CV) of ­systolic BP in the hyperacute phase than shown by patients without insular infarction (p < 0.01, p < 0.01, p = 0.02, and p = 0.03, respectively). The SD and CV of systolic BP in the hyperacute phase showed significant differences among the 3 groups with right insular infarction, with left insular infarction, and without insular infarction (p < 0.05 and p < 0.05, respectively). There was a tendency for the systolic BP variability to be lower in patients with right anterior insular infarction than in patients with infarcts in other areas. Conclusion: The right insular cortex, especially the anterior part, might be a hub for autonomic nervous regulation.

Neural coupling between contralesional motor and frontoparietal networks correlates with motor ability in individuals with chronic stroke

Movement is traditionally viewed as a process that involves motor brain regions. However, movement also implicates non-motor regions such as prefrontal and parietal cortex, regions whose integrity may thus be important for motor recovery after stroke. Importantly, focal brain damage can affect neural functioning within and between distinct brain networks implicated in the damage. The aim of this study is to investigate how resting state connectivity (rs-connectivity) within and between motor and frontoparietal networks are affected post-stroke in correlation with motor outcome. Twenty-seven participants with chronic stroke with unilateral upper limb deficits underwent motor assessments and magnetic resonance imaging. Participants completed the Chedoke-McMaster Stroke Assessment as a measure of arm (CMSA-Arm) and hand (CMSA-Hand) impairment and the Action Research Arm Test (ARAT) as a measure of motor function. We used a seed-based rs-connectivity approach defining the motor (seed=contralesional primary motor cortex (M1)) and frontoparietal (seed=contralesional dorsolateral prefrontal cortex (DLPFC)) networks. We analyzed the rs-connectivity within each network (intra-network connectivity) and between both networks (inter-network connectivity), and performed correlations between: a) intra-network connectivity and motor assessment scores; b) inter-network connectivity and motor assessment scores. We found: a) Participants with high rs-connectivity within the motor network (between M1 and supplementary motor area) have higher CMSA-Hand stage (z=3.62, p=0.003) and higher ARAT score (z=3.41, p=0.02). Rs-connectivity within the motor network was not significantly correlated with CMSA-Arm stage (z=1.83, p>0.05); b) Participants with high rs-connectivity within the frontoparietal network (between DLPFC and mid-ventrolateral prefrontal cortex) have higher CMSA-Hand stage (z=3.64, p=0.01). Rs-connectivity within the frontoparietal network was not significantly correlated with CMSA-Arm stage (z=0.93, p=0.03) or ARAT score (z=2.53, p=0.05); and c) Participants with high rs-connectivity between motor and frontoparietal networks have higher CMSA-Hand stage (r_s=0.54, p=0.01) and higher ARAT score (r_s=0.54, p=0.009). Rs-connectivity between the motor and frontoparietal networks was not significantly correlated with CMSA-Arm stage (r_s=0.34, p=0.13). Taken together, the connectivity within and between the motor and frontoparietal networks correlate with motor outcome post-stroke. The integrity of these regions may be important for an individual's motor outcome. Motor-frontoparietal connectivity may be a potential biomarker of motor recovery post-stroke.

Immunohistochemical expression profiles of mucin antigens in salivary gland mucoepidermoid carcinoma: MUC4- and MUC6-negative expression predicts a shortened survival in the early postoperative phase

In mucoepidermoid carcinoma (MEC), the most common salivary gland carcinoma, there is a lack of novel prognostic markers, but post-operative early recurrence strongly affects the clinical course and a poor outcome. It is critical to predict which MEC patients are prone to develop recurrence/metastases. Mucins play pivotal roles in influencing cancer biology, thus affecting cell differentiation, adhesion, carcinoma invasion, aggressiveness and/or metastatic potential. Our aim is to elucidate the significance of expression profiles for mucins, particularly MUC4 and MUC6, and their correlations with various clinicopathological features and recurrence in salivary gland MECs. We performed immunohistochemical analyses on patients with surgically resected primary MEC using antibodies against mucin core proteins MUC4/8G7 and MUC6/CLH5 in 73 paraffin-embedded samples. Recurrence was noted in 15 of 73 (20.5%) patients. MUC4 or MUC6 expression was considered to be negative when <30% or 0% of the MEC cells showed positive staining, respectively. MUC4- and/or MUC6-negative expression respectively and variably showed a significant relationship to pathological tumor high-grade, the presence of lymphovascular invasion, lymph node metastasis and/or tumor-related death. In addition, MUC4 showed significantly negative co-expression with MUC6. Kaplan-Meier analyses revealed that not only single MUC4/6-negative expression but also the combination of both predicted significantly shorter disease-free and disease-specific survivals in MECs, especially within the first two years postoperatively. Therefore, each mucin plays a pivotal role in the pathogenesis of MEC progression. The detection of MUC4 and/or MUC6 might be a powerful parameter in the clinical management of MECs in the early postsurgical phase.

Trail Making Test Elucidates Neural Substrates of Specific Poststroke Executive Dysfunctions

BACKGROUND AND PURPOSE

Poststroke cognitive impairment is typified by prominent deficits in processing speed and executive function. However, the underlying neuroanatomical substrates of executive deficits are not well understood, and further elucidation is needed. There may be utility in fractionating executive functions to delineate neural substrates.

METHODS

One test amenable to fine delineation is the Trail Making Test (TMT), which emphasizes processing speed (TMT-A) and set shifting (TMT-B-A difference, proportion, quotient scores, and TMT-B set-shifting errors). The TMT was administered to 2 overt ischemic stroke cohorts from a multinational study: (1) a chronic stroke cohort (N=61) and (2) an acute-subacute stroke cohort (N=45). Volumetric quantification of ischemic stroke and white matter hyperintensities was done on magnetic resonance imaging, along with ratings of involvement of cholinergic projections, using the previously published cholinergic hyperintensities projections scale. Damage to the superior longitudinal fasciculus, which colocalizes with some cholinergic projections, was also documented.

RESULTS

Multiple linear regression analyses were completed. Although larger infarcts (β=0.37, P<0.0001) were associated with slower processing speed, cholinergic hyperintensities projections scale severity (β=0.39, P<0.0001) was associated with all metrics of set shifting. Left superior longitudinal fasciculus damage, however, was only associated with the difference score (β=0.17, P=0.03). These findings were replicated in both cohorts. Patients with ≥2 TMT-B set-shifting errors also had greater cholinergic hyperintensities projections scale severity.

CONCLUSIONS

In this multinational stroke cohort study, damage to lateral cholinergic pathways and the superior longitudinal fasciculus emerged as significant neuroanatomical correlates for executive deficits in set shifting.

Progression of limb apraxia in corticobasal syndrome: neuropychological and functional neuroimaging report of a case series

The current study described the progression of limb apraxia in seven corticobasal syndrome patients through a comprehensive battery, including both gesture production tasks and conceptual tool/action knowledge tasks. The examination of the behavioral and neuroimaging (SPECT) data revealed two patient subgroups. One group consisted of patients with preserved conceptual tool/action knowledge, relatively mild gesture production and neuropsychological deficits with few significantly hypoperfused regions of interest. The other group consisted of those whose conceptual tool/action knowledge and general cognition eventually deteriorated and who were quite severely affected in their gesture production performance. These patients were characterized by bilateral hypoperfusion in parietal regions and in one case bilateral anterior cingulate regions.

Differentiating between visual hallucination-free dementia with Lewy bodies and corticobasal syndrome on the basis of neuropsychology and perfusion single-photon emission computed tomography

INTRODUCTION

Dementia with Lewy bodies (DLB) and Corticobasal Syndrome (CBS) are atypical parkinsonian disorders with fronto-subcortical and posterior cognitive dysfunction as common features. While visual hallucinations are a good predictor of Lewy body pathology and are rare in CBS, they are not exhibited in all cases of DLB. Given the clinical overlap between these disorders, neuropsychological and imaging markers may aid in distinguishing these entities.

METHODS

Prospectively recruited case-control cohorts of CBS (n =31) and visual hallucination-free DLB (n =30), completed neuropsychological and neuropsychiatric measures as well as brain perfusion single-photon emission computed tomography and structural magnetic resonance imaging (MRI). Perfusion data were available for forty-two controls. Behavioural, perfusion, and cortical volume and thickness measures were compared between the groups to identify features that serve to differentiate them.

RESULTS

The Lewy body with no hallucinations group performed more poorly on measures of episodic memory compared to the corticobasal group, including the delayed and cued recall portions of the California Verbal Learning Test (F (1, 42) =23.1, P <0.001 and F (1, 42) =14.0, P =0.001 respectively) and the delayed visual reproduction of the Wechsler Memory Scale-Revised (F (1, 36) =9.7, P =0.004). The Lewy body group also demonstrated reduced perfusion in the left occipital pole compared to the corticobasal group (F (1,57) =7.4, P =0.009). At autopsy, the Lewy body cases all demonstrated mixed dementia with Lewy bodies, Alzheimer's disease and small vessel arteriosclerosis, while the corticobasal cases demonstrated classical corticobasal degeneration in five, dementia with agyrophilic grains + corticobasal degeneration + cerebral amyloid angiopathy in one, Progressive Supranuclear Palsy in two, and Frontotemporal Lobar Degeneration-Ubiquitin/TAR DNA-binding protein 43 proteinopathy in one. MRI measures were not significantly different between the patient groups.

CONCLUSIONS

Reduced perfusion in the left occipital region and worse episodic memory performance may help to distinguish between DLB cases who have never manifested with visual hallucinations and CBS at earlier stages of the disease. Development of reliable neuropsychological and imaging markers that improve diagnostic accuracy will become increasingly important as disease modifying therapies become available.

Congenital absence of the mammillary bodies: a novel finding in a well-studied case of developmental amnesia

Individuals with developmental amnesia experience compromised development of episodic memory for details of personal life events, believed to relate to changes to the hippocampus after birth. Here we report the very rare discovery of aplasia of the mammillary bodies, hypogenesis of the fornix, and abnormal hippocampal shape and orientation in H.C., a well-documented case of selectively compromised episodic memory development who is the subject of numerous published empirical articles. These anatomical abnormalities are highly suggestive of disrupted extended hippocampal system development very early in gestation, despite an original diagnosis of developmental amnesia and assumed perinatal hypoxia. These findings provide a unique window into the normal function of the mammillary bodies, fornices, and related anterior nuclei of the thalamus bilaterally. The results also encourage re-examination of the pathological basis of developmental amnesia in other cases reported in the literature.

Emerging roles for the FCRL family members in lymphocyte biology and disease

Members of the extended Fc receptor-like (FCRL) family in humans and mice are preferentially expressed by B cells and possess tyrosine-based immunoregulatory function. Although the majority of these proteins repress B cell receptor-mediated activation, there is an emerging evidence for their bifunctionality and capacity to counter-regulate adaptive and innate signaling pathways. In light of these findings, the recent discovery of ligands for several of these molecules has begun to reveal exciting potential for them in normal lymphocyte biology and is launching a new phase of FCRL investigation. Importantly, these fundamental developments are also setting the stage for defining their altered roles in the pathogenesis of a growing number of immune-mediated diseases. Here we review recent advances in the FCRL field and highlight the significance of these intriguing receptors in normal and perturbed immunobiology.

Complexity of MRI white matter hyperintensity assessments in relation to cognition in aging and dementia from the Sunnybrook Dementia Study

PURPOSE

Quantification methods for white matter hyperintensities (WMH) on Magnetic Resonance Imaging are heterogeneous, deterring their application. This study compared three WMH rating scales, varying in complexity, and a volumetric method, to evaluate trade-offs between complexity and clinical utility in differentiating dementia subgroups and in correlating with cognition.

METHODS

WMH were rated using the Fazekas, Age-Related White Matter Changes (ARWMC) and Scheltens scales, and segmented by computational volumetry in 108 patients with Alzheimer's Disease (AD), 23 with Mild Cognitive Impairment (MCI) and 34 normal controls (NC). Global and hippocampal atrophy, age and education, were accounted for in correlations of WMH with cognitive domains.

RESULTS

Intra- and inter-rater reliability were high (intraclass correlation coefficients = 0.88-0.97) across rating scales. WMH scores of all scales were highly correlated with volumes (Spearman r = 0.78-0.90, Ps < 0.001), as well as with each other (Spearman r = 0.86-0.91, Ps < 0.001). The Fazekas scale showed significant separation between AD, MCI and NC using non-parametric analysis, while the ARWMC and Scheltens' scales, and WMH volumes demonstrated significant correlations (standardized β = -0.19 to -0.24, Ps < 0.05) with cognitive domain scores using multivariate regression analysis, controlling for age, education, global and hippocampal atrophy in patients with AD.

CONCLUSIONS

This study suggests that the degree of complexity of WMH rating scales did not affect validation against WMH volumes, but did vary in validation against cognition. The simplest scale performed best in separating cognitive subgroups, but the more complex scales and quantification correlated better with cognitive measures, especially executive function. Hence the best choice of scale depends on the particular application.

Alzheimer's disease and infection: do infectious agents contribute to progression of Alzheimer's disease?

Infection with several important pathogens could constitute risk factors for cognitive impairment, dementia, and Alzheimer's disease (AD) in particular. This review summarizes the data related to infectious agents that appear to have a relationship with AD. Infections with herpes simplex virus type 1, picornavirus, Borna disease virus, Chlamydia pneumoniae, Helicobacter pylori, and spirochete were reported to contribute to the pathophysiology of AD or to cognitive changes. Based on these reports, it may be hypothesized that central nervous system or systemic infections may contribute to the pathogenesis or pathophysiology of AD, and chronic infection with several pathogens should be considered a risk factor for sporadic AD. If this hypothesis holds true, early intervention against infection may delay or even prevent the future development of AD.

Intraarticular administration of platelet-rich plasma with biodegradable gelatin hydrogel microspheres prevents osteoarthritis progression in the rabbit knee

OBJECTIVE

To investigate the therapeutic potential of administration of gelatin hydrogel microspheres containing platelet-rich plasma (PRP), by examining its effects on progression of osteoarthritis (OA) in a rabbit model.

METHODS

PRP and platelet-poor plasma (PPP) were prepared from rabbit blood. Adult rabbit chondrocytes were cultured in the alginate beads with the presence of 3% PRP or 3% PPP. Glycosaminoglycan (GAG) synthesis was quantified using dimethylmethylene blue assay. To confirm the anabolic effect of PRP in vivo, cartilage matrix gene expression was examined after intraarticular administration of PRP contained in gelatin hydrogel microspheres. The PRP contained in gelatin hydrogel microspheres was administered into the rabbit knee joint twice with an interval of 3 weeks, beginning 4 weeks after anterior cruciate ligament transection (ACLT). Ten weeks after ACLT, gross morphological and histological examinations were performed.

RESULTS

PRP significantly stimulated chondrocyte GAG synthesis in vitro. In the knee joint, expression of proteoglycan core protein mRNA in the articular cartilage increased after administration of PRP contained in microspheres. Intraarticular injections of PRP in gelatin hydrogel microspheres significantly suppressed progression of OA in the ACLT rabbit model morphologically and histologically.

CONCLUSION

The present findings indicate that sustained release of growth factors contained in PRP has preventive effects against OA progression. These preventive effects appear to be due to stimulation of cartilage matrix metabolism, caused by the growth factors contained in PRP.

Comparison of manual and semi-automated delineation of regions of interest for radioligand PET imaging analysis

Background

As imaging centers produce higher resolution research scans, the number of man-hours required to process regional data has become a major concern. Comparison of automated vs. manual methodology has not been reported for functional imaging. We explored validation of using automation to delineate regions of interest on positron emission tomography (PET) scans. The purpose of this study was to ascertain improvements in image processing time and reproducibility of a semi-automated brain region extraction (SABRE) method over manual delineation of regions of interest (ROIs).

Methods

We compared 2 sets of partial volume corrected serotonin 1a receptor binding potentials (BPs) resulting from manual vs. semi-automated methods. BPs were obtained from subjects meeting consensus criteria for frontotemporal degeneration and from age- and gender-matched healthy controls. Two trained raters provided each set of data to conduct comparisons of inter-rater mean image processing time, rank order of BPs for 9 PET scans, intra- and inter-rater intraclass correlation coefficients (ICC), repeatability coefficients (RC), percentages of the average parameter value (RM%), and effect sizes of either method.

Results

SABRE saved approximately 3 hours of processing time per PET subject over manual delineation (p < .001). Quality of the SABRE BP results was preserved relative to the rank order of subjects by manual methods. Intra- and inter-rater ICC were high (>0.8) for both methods. RC and RM% were lower for the manual method across all ROIs, indicating less intra-rater variance across PET subjects' BPs.

Conclusion

SABRE demonstrated significant time savings and no significant difference in reproducibility over manual methods, justifying the use of SABRE in serotonin 1a receptor radioligand PET imaging analysis. This implies that semi-automated ROI delineation is a valid methodology for future PET imaging analysis.

Quantitative Assessment of Cerebral Blood Flow in Genetically Confirmed Spinocerebellar Ataxia Type 6

BACKGROUND

Spinocerebellar ataxia type 6 (SCA6) is an autosomal dominant cerebellar ataxia caused by CAG trinucleotide expansion. The characteristics of regional cerebral blood flow (rCBF) in SCA6 patients have not been established, whereas it has been reported that decreased rCBF in the cerebrum seems to be a remote effect of cerebellar impairment in other cerebellar disorders.

OBJECTIVE

To clarify the characteristics of rCBF, including cerebro-cerebellar relationship, and its correlation with clinical manifestations in patients with genetically confirmed SCA6 using quantitative assessment of rCBF by brain single-photon emission computed tomography (SPECT).

DESIGN

Technetium Tc 99m ethyl cysteinate dimer SPECT study using a Patlak plot. Patients Hiroshima University Hospital, Hiroshima, Japan. Ten patients with SCA6 and 9 healthy controls. Main Outcome Measure The rCBF of the cerebellar vermis, cerebellar hemisphere, and frontal lobes.

RESULTS

In SCA6 patients, rCBF was decreased only in the cerebellar vermis and hemisphere compared with healthy controls, and this was inversely correlated with duration of illness. The rCBF in the frontal lobes was slightly correlated with duration of illness without statistical significance. The rCBF in the vermis was inversely correlated with severity of dysarthria, but there was no significant correlation with CAG repeated expansions.

CONCLUSIONS

Decrease in rCBF was found only in the cerebellum and was associated with duration of illness, dysarthria and ataxia, and cerebellar atrophy. No remote effect of cerebellar hypoperfusion was found in the SCA6 patients.

Perceived importance of being thin and smoking initiation among young girls

BACKGROUND

Smoking among adolescents remains unacceptably high and the difference in potential risk factors for smoking initiation between male and female adolescents has been explored. Although the association between smoking initiation and dieting behaviour has been observed among girls, the mechanism of the association is unknown.

OBJECTIVE

To examine prospectively the association between perceived importance of being thin at baseline and smoking initiation among girls.

DESIGN

A four year prospective cohort survey including perceived importance of being thin at baseline and smoking behaviour, conducted in 1993 and 1996.

SETTING AND PARTICIPANTS

273 Massachusetts female adolescents aged 12-15 years at baseline who reported having smoked no more than one cigarette by the time of the baseline survey, drawn from households sampled by random digit dialing.

MAIN OUTCOME MEASURE

Progression to established smoking, defined as having smoked 100 or more cigarettes in their lifetime.

RESULTS

After adjusting for age, smoking status at baseline, and race/ethnicity, girls who valued thinness most strongly and somewhat strongly were both more likely to have become established smokers, compared to the girls who valued thinness least strongly. The odds ratios are 4.5 (95% confidence interval (CI), 1.4 to 16.7) and 3.4 (95% CI 1.04 to 10.9), respectively.

CONCLUSIONS

The level of perceived importance of being thin among young female adolescents predicts future smoking initiation. Smoking prevention programmes designed for female adolescents may therefore benefit from the inclusion of content related to importance of being thin.

Magnetization transfer measurements of brain structures in patients with multiple system atrophy

To determine whether magnetization transfer imaging (MTI) demonstrates abnormalities in the brain structures of patients with multiple system atrophy (MSA), we examined 12 patients with clinically probable MSA and 11 control subjects. We calculated magnetization transfer ratios (MTRs) using region of interest analysis from MTI and assessed abnormal signal changes on T2-weighted images. MTRs of the base of the pons, middle cerebellar peduncle, putamen, and white matter of the precentral gyrus were significantly lower in the MSA patients than in the controls. Abnormal signal changes on T2-weighted images were observed in the base of the pons (n = 6), middle cerebellar peduncle (n = 7), and putamen (n = 7). MTRs of regions with abnormal signals were significantly lower than those of regions without abnormal signals and those in the controls. Even the MTRs of the regions without abnormal signals were lower than those in the controls. MTRs of the pyramidal tract, including white matter of the precentral gyrus, posterior limb of the internal capsule, cerebral peduncle, and base of the pons, were significantly lower in patients with pyramidal tract sign (n = 7) than in the controls. Patients with asymmetrical parkinsonism (n = 5) showed significantly lower MTRs in the putamen contralateral to the predominant side of parkinsonian symptoms than the ipsilateral side, although asymmetry of abnormal signal changes on T2-weighted images was not evident in more than half of those patients. This study showed that MTI demonstrates abnormalities in the brains of patients with MSA that seem to reflect underlying pathological changes and that the pathological changes detected by MTI seem to give rise to clinical symptoms. This study also showed that the abnormalities are detected more sensitively and over a larger area by MTI than by conventional magnetic resonance imaging.

[A case of late onset mitochondrial neuromyopathy]

A 68-year-old woman was admitted with dysesthesia on both soles, hands and buttocks. She first noticed the dysesthesia in the left first toe two years before admission. One year before admission, serum creatine kinase and lactate dehydrogenase levels were elevated but she had no clinical symptoms suggesting myopathy. Nerve conduction study showed no apparent abnormalities, and an electromyogram showed mild myogenic change. Computed tomography of the muscle showed fatty degeneration of the trunk, major gluteus muscle, and biceps femoris muscle and atrophic change of the biceps femoris muscle. Muscle biopsy revealed a slight variation in fiber size, the presence of cytochrome c oxidase (CCO)-negative fibers by CCO staining, ragged-red fibers by Gomori trichrome staining, and mild denervation fiber by neuron specific enolase (NSE) staining. Analysis of her mitochondrial DNA (mtDNA) revealed a large deletion of mtDNA (approximately 8.5 Kb), and mitochondrial neuromyophy was diagnosed. The frequency of mtDNA deletion increases with aging. Although her mtDNA abnormality was compatible with chronic progressive external ophthalmoplegia (CPEO), we speculate that the aging process may be contributed to the mtDNA abnormality, which would be related to the late onset of her symptoms. As the phenotype of this mitochondrial disorder shows a wide variation and mtDNA abnormality is more frequent among elderly people, we should consider the possibility of mitochondrial disorders even in elderly people.

Magnetization transfer measurements of cerebral white matter in patients with myotonic dystrophy

To determine whether patients with myotonic dystrophy (MyD) have structural changes in the cerebral white matter, we performed magnetization transfer (MT) imaging of the cerebral white matter in 14 MyD patients and 11 age-matched normal controls. We calculated MT ratios in both the white matter lesions (WMLs) and the normal-appearing white matter (NAWM) of MyD patients using region of interest (ROI) analysis. MT ratios in WMLs were markedly decreased, and all ROIs in NAWM also showed significantly lower MT ratios in MyD patients than in normal controls. The average MT ratio of all ROIs in WMLs and NAWM in each patient showed a significant negative correlation with duration of illness, but not with the patient's age or age at onset. The results of the present study indicate not only the presence of pathological changes in WMLs but also the widespread involvement of NAWM in MyD patients. The results also suggest that structural changes in the white matter may be progressive during the clinical course of MyD.

Hepatic parenchymal enhancement in the cirrhotic liver: evaluation by triple-phase dynamic MRI

BACKGROUND

To evaluate the changes of liver parenchymal enhancement in the cirrhotic liver by means of triple-phase dynamic magnetic resonance (MR) imaging.

METHODS

Triple-phase multisection dynamic MR imaging was performed in 32 patients with liver cirrhosis. The control group consisted of 19 patients without liver cirrhosis. After precontrast images were obtained, arterial phase images were acquired 20 s after the start of intravenous bolus administration of 0.10 mmol/kg of gadopentetate dimeglumine. Portal and delayed phase images were then acquired 1 and 3 min, respectively, after the injection of contrast material. On each phase image, the signal-to-noise ratio (S/N) from the liver parenchyma was measured by operator-defined regions of interest (ROIs). The contrast-enhanced ratio (CER) on each phase was then obtained according to the following formula: [S/N(arterial or portal or delayed phase image) - S/N(precontrast image)] / S/N(precontrast image). The portal perfusion index (PPI) also was obtained according to the following formula: [S/N(portal phase image - S/N(arterial phase image)] / S/N(arterial phase image). The results were expressed as mean +/- SD.

RESULTS

The CERs of arterial, portal, and delayed phase images in patients with and without liver cirrhosis were 0.256 +/- 0.211, 0.640 +/- 0.384, and 0.554 +/- 0.318 and 0.132 +/- 0.094, 0.404 +/- 0.204, and 0.324 +/- 0.144, respectively. The CERs were highest in the portal phase and lowest in the arterial phase in patients with and without liver cirrhosis. The CER of the cirrhotic liver was significantly higher than that of the normal liver in every phase (p < 0.05). PPIs with and without liver cirrhosis were 2.90 +/- 4.03 and 3.86 +/- 3.89, respectively. The PPI with liver cirrhosis was significantly lower than that without liver cirrhosis (p < 0.05).

CONCLUSION

The enhancement of cirrhotic liver parenchyma is greater than that of the normal liver parenchyma at every phase of triple-phase dynamic MR imaging.

Four subunit a isoforms of Caenorhabditis elegans vacuolar H+-ATPase. Cell-specific expression during development

We have identified four genes (vha-5, vha-6, vha-7, and unc-32) coding for vacuolar-type proton-translocating ATPase (V-ATPase) subunit a in Caenorhabditis elegans, the first example of four distinct isoforms in eukaryotes. Their products had nine putative transmembrane regions, exhibited 43-60% identity and 62-84% similarity with the bovine subunit a1 isoform, and retained 11 amino acid residues essential for yeast V-ATPase activity (Leng, X. H., Manolson, M. F., and Forgac, M. (1998) J. Biol. Chem. 273, 6717-6723). The similarities, together with the results of immunoprecipitation, suggest that these isoforms are components of V-ATPase. Transgenic and immunofluorescence analyses revealed that these genes were strongly expressed in distinct cells; vha-5 was strongly expressed in an H-shaped excretory cell, vha-6 was strongly expressed in intestine, vha-7 was strongly expressed in hypodermis, and unc-32 was strongly expressed in nerve cells. Furthermore, the vha-7 and unc-32 genes were also expressed in the uteri of hermaphrodites. RNA interference analysis showed that the double-stranded RNA for unc-32 caused embryonic lethality similar to that seen with other subunit genes (vha-1, vha-4, and vha-11) (Oka, T., and Futai, M. (2000) J. Biol. Chem. 275, 29556-29561). The progenies of worms injected with the vha-5 or vha-6 double-stranded RNA became died at a specific larval stage, whereas the vha-7 double-stranded RNA showed no effect on development. These results suggest that V-ATPases with these isoforms generate acidic compartments essential for worm development in a cell-specific manner.

Sequence heterogeneity of the ten rRNA operons in Clostridium perfringens

We have cloned and sequenced rRNA operons of Clostridium perfringens strain 13 and analyzed the sequence structure in view of the phylogenesis. The organism had ten copies of rRNA operons all of that comprised of 16S, 23S and 5S rDNAs except for one operon. The operons clustered around the origin of replication, ranging within one-third of the whole genome sequence as it is arranged in a circle. Seven operons were transcribed in clockwise direction, and the remaining three were transcribed in counter clockwise direction assuming that the gyrA was transcribed in clockwise direction. Two of the counter clockwise operons contained tRNA(Ile) genes between the 16S and 23S rDNAs, and the other had a tRNA(Ile) genes between the 16S and 23S rDNAs and a tRNA(Asn) gene in the place of the 5S rDNA. Microheterogeneity was found within the rRNA structural genes and spacer regions. The length of each 16S, 23S and 5S rDNA were almost identical among the ten operons, however, the intergenic spacer region of 16S-23S and 23S-5S were variable in the length depending on loci of the rRNA operons on the chromosome. Nucleotide sequences of the helix 19, helix 19a, helix 20 and helix 21 of 23S rDNA were divergent and the diversity appeared to be correlated with the loci of the rRNA operons on the chromosome.

Inferior phrenic arteries: depiction with thin-section three-dimensional contrast-enhanced dynamic MR imaging with fat suppression

The purpose of this study was to evaluate visibility of the inferior phrenic arteries in normal subjects at thin-section, multiphasic, three-dimensional (3D) contrast-enhanced dynamic magnetic resonance (MR) imaging with fat suppression, and to compare the appearances and frequencies of MR visualization of these vessels between normal and cirrhotic patients. This study included 95 patients (44 normal and 51 cirrhotic patients) who underwent 3D contrast-enhanced dynamic imaging on a high-performance gradient (25 mT/m) system as a part of abdominal MR examinations. The right and left inferior phrenic arteries were visible in 84% and 73% of the normal subjects, respectively. The averaged rating for visibility in the right inferior phrenic artery was significantly greater in the cirrhotic patients than in the normal subjects (2.1 +/- 0.1 vs. 1.7 +/- 0.2; P = 0.040). Mean diameters of the right inferior phrenic artery in the cirrhotic patients (1.7 +/- 0.1 mm) were significantly larger (P = 0.002) than those in the normal subjects (1.3 +/- 0.1 mm). No significant difference was noted in the mean diameters and the visibility of the left inferior phrenic artery between the two groups. The inferior phrenic arteries can frequently be identified on thin-section, 3D contrast-enhanced arterial-phase dynamic MR images with fat-suppression techniques. Dilatation of the right inferior phrenic artery depicted by this technique may be a nonspecific but an additional secondary finding suggestive of cirrhosis.

Heterogeneity of T cell clones specific for a single indirect alloantigenic epitope (I-Ab/H-2Kd54-68) that mediate transplant rejection

BACKGROUND

One of the complexities of solid organ allograft rejection is the inherent diversity of the specific T cell antigenic epitopes that participate in this response, including the role of direct alloantigen recognition and indirect recognition of donor-derived peptides in recipient antigen-presenting cells. To probe the role of distinct T cell receptor (TCR) avidity differences and the role of cytokine expression patterns of different effector T cells that may participate in allograft rejections, we have identified a dominant allopeptide derived from the H-2Kd molecule, recognized by H-2b CD4 T cells in the context of syngeneic I-Ab.

METHODS

To identify a stimulatory peptide derived from the H-2Kd molecule, a panel of synthetic overlapping peptides was screened for immunogenicity and a panel of T cell clones established. These clones were characterized for TCR Vbeta usage by mAb staining and/or reverse transcribed-polymerase chain reaction analysis, peptide dose sensitivity as a marker of TCR avidity, cytokine expression phenotype in vitro, and their ability to mediate rejection of a vascularized cardiac allograft after adoptive transfer to immunodeficient mice.

RESULTS

The H-2Kd54-68 peptide was identified as a dominant stimulatory peptide by the ability of T cells from C57BL/6 (H-2b) mice primed by a combination of allogeneic spleen cell injection and mixed peptide immunization to mount an in vitro proliferative response and interferon-gamma production by peptide stimulation. Furthermore, direct immunization with synthetic H-2Kd54-68 peptide of normal C57BL/6 mice resulted in accelerated rejection of both skin and cardiac allografts from B10.D2 (H-2d) mice, but not 3rd party B10.BR (H-2k) grafts. A panel of 15 distinct CD4+ clones specific for H-2Kd54-68 peptide were established and shown to utilize a variety of TCR Vbeta and different apparent TCR avidities to H-2Kd54-68 peptide when stimulated in vitro. To characterize these clones further, two clones were chosen based on the difference of avidity to H-2Kd54-68 peptide. The cytokine expression pattern was determined and indirect alloantigen specificity confirmed by analysis of responses to purified peptide and B10.D2 spleen cells using normal H.2b and I-Abeta chain knockout mice as APC donors. Both of these T cell clones were able to mediate rejection of B10.D2, but not B10.BR hearts, in immunodeficient mice, but the morphological pattern of T cell infiltration was distinct.

CONCLUSIONS

These results demonstrate the potential importance of fine dissection of the alloantigeneic response to solid organ transplants and provide unique insights into the role of TCR avidity and cytokine expression patterns in different morphological patterns of transplant rejection.

Effects of market liberalisation on smoking in Japan

OBJECTIVE

To document the effect of the liberalisation of the Japanese tobacco market on Japanese smoking rates and on Japanese tobacco industry practices.

DATA SOURCE

Asahi Shimbun (major daily newspaper) from 1980 to 1996.

STUDY SELECTION

Review of media coverage on the effects of market liberalisation following the imposition of the USA's section 301 trade sanction.

DATA SYNTHESIS

The opening of Japan's tobacco market to foreign cigarette companies stalled a decline in smoking prevalence. Smoking rates among young women increased significantly, and also appear to be on the rise among adolescents. Aggressive marketing and promotional activities by US and Japanese tobacco companies in response to trade liberalisation appear responsible for these adverse trends. Steep increases in sales through vending machines were also possible contributors to the rising smoking prevalence among adolescents. On the positive side, market liberalisation indirectly promoted smoking control efforts in Japan, by causing an anti-smoking movement to coalesce.

CONCLUSION

Market liberalisation in Japan played a significant role in increasing smoking prevalence among young women and adolescents while helping to transform the issue of smoking in Japan from a matter of individual choice to a public health problem.

Foreign serum-induced bile duct lesion (BDL) in athymic BALB/c nude mice

To investigate a role of cellular immunity in foreign serum-induced bile duct lesion (BDL) in mice, athymic BALB/c nude (nu/nu) mice were intraperitoneally injected with swine serum (SS) twice a week up to 8 weeks and were compared with euthymic BALB/c heterozygote (nu/+) and wild-type (+/+) mice treated with SS in the same way for 4 weeks. All immunized nu/+ and +/+ mice developed marked BDL, and their sera showed high anti-SS IgE and IgG1 antibody titers, whereas no immunized nu/nu mice developed lesions, and their sera showed no elevation of antibody titers. Next, nu/nu mice were reconstituted with splenocytes derived from nu/+ mice, and then were intraperitoneally injected with SS twice a week for 3 weeks. Most of the reconstituted nu/nu mice developed BDL, and their sera showed the elevation of anti-SS IgE and IgG antibody titers. These results suggest that cellular immunity may play a pivotal role in the pathogenesis of swine serum-induced BDL.

Immunopathological study on the development of swine serum-induced bile duct lesions in BALB/c and DBA/2 mice

To compare the difference in the development of swine serum (SS)-induced bile duct lesion (BDL) between high responder BALB/c and low responder DBA/2 mice, the mice of both strains injected with SS twice a week for up to 4 weeks were killed and examined immunopathologically after the 2nd, 4th, 6th and 8th SS-injection, respectively. In BALB/c mice, BDL developed rapidly following the SS-injections, and a slight enlargement of common bile ducts accompanied with infiltration of T helper cells and eosinophils was detected after the 2nd SS-injection. From the 4th injection on, BDL was characterized by proliferation of mucous glands, hyperplasia and hypertrophy of biliary and glandular epithelial cells, periductal fibrosis, infiltration of eosinophils, plasma cells and T helper cells, and increase of mast cells, resulting in more apparent enlargement of common bile ducts. Several hypertrophied biliary and glandular epithelial cells were positive for mouse immunoglobulins and SS. BDL subsided after cessation of the SS-treatment. On the other hand, in DBA/2 mice, immune response and inflammatory reaction were very weak, and only slight BDL were detected.

Oddi sphincter and common channel: evaluation with pharmacodynamic MR cholangiopancreatography using fatty meal and secretin stimulation

PURPOSE

This study was performed to assess the usefulness of pharmacodynamic MR cholangiopancreatography (MRCP) in depicting the segment covered by the Oddi sphincter.

MATERIALS AND METHODS

Twelve volunteers were studied by pharmacodynamic MRCP. After stimulation by the oral intake of a fatty meal and an intravenous injection of secretin, a single-shot rapid acquisition relaxation enhancement (RARE) sequence was used to obtain consecutive images of the segment covered by the Oddi sphincter. The contraction range of the Oddi sphincter and the lengths of the common channel were measured on the MR console by comparing the most contracted image of the sphincter with the most relaxed image.

RESULTS

Pharmacodynamic MRCP showed periodic contraction of the Oddi sphincter in all cases. The range of sphincteric contraction over the biliary duct was 8-19 mm (11.8+/-3.2 mm, mean +/- standard deviation) and over the pancreatic duct 8-23 mm (10.0+/-1.5 mm). In 11 of the 12 cases, the common channel was depicted and its length ranged from 3-8 mm (5.2+/-1.3 mm).

CONCLUSION

Pharmacodynamic MRCP clearly depicted the range of contraction of the Oddi sphincter and the common channel, which are not usually revealed by conventional MRCP.

A preliminary study of discrimination among the components of small pulmonary nodules by MR imaging: correlation between MR images and histologic appearance

PURPOSE

To investigate whether magnetic resonance (MR) imaging depicts the internal characteristics of small pulmonary nodules.

METHODS

We reviewed MR images of 39 surgically resected pulmonary nodules 3 cm or less and compared the components within the nodules. In 22 malignant nodules, eight histologic components were characterized by signal and enhancement patterns on MR images.

RESULTS

MR images obtained from any single sequence discriminated all components in 26 (67%) nodules, whereas the combination of images from various sequences allowed discrimination in 35 (90%). Fourteen of 16 components of aggregated tumor cells showed marked early enhancement. Although fibrotic and necrotic components showed no or slight early enhancement, nine of 10 fibrotic components showed hypointensity and six of seven necrotic components showed hyperintensity on T2-weighted images. Component characterization in eight histologies by MR imaging was possible in 71-100%.

CONCLUSION

Our study demonstrated that MR imaging offers the possibility of high tissue-contrast resolution in small pulmonary nodules.

[Outpatient chemotherapy with infusional 5-fluorouracil in advanced gastrointestinal cancer]

These studies were designed to evaluate the efficacy, toxicity, and resulting quality of life (QOL) of outpatient chemotherapy with infusional 5-FU for advanced gastrointestinal cancer. Schedule, sch. A: Treatment consisted of CI 5-FU 200 mg/m2/day, days 1-28, IVB Leucovorin 20 mg/m2 q week. Fifteen patients with advanced gastrointestinal cancer were treated to maintain the efficacy of prior inpatient chemotherapy. Twenty-one patients treated with adjuvant chemotherapy were added to evaluate toxicity and QOL. The mean time to progression (TTP) was 2.6 months. Grade 2 toxicities were seen, including mucositis (23%) and diarrhea (7%). Hand-foot syndrome was seen 60% of patients. The mean QOL score was 89.5 +/- 7.8. Sch.B: Treatment consisted of weekly 24 h infusion of 5-FU 2,600 mg/m2. 5-FU was administered using a Groshong catheter and Baxter infusor LV5 (5 ml/hr). Nine patients with advanced gastrointestinal cancer were treated. Twenty-one patients were treated with adjuvant chemotherapy. The mean TTP was 3.6 month. Grade 2 toxicities were seen, including leucocytopenia (7%), mucositis (3%), diarrhea (10%), and nausea and vomiting (10%). The mean QOL score was 82.6 +/- 10.7. In conclusion, both 5-FU schedules are feasible for outpatient chemotherapy for advanced gastrointestinal cancer.