Higher handgrip strength is linked to higher salience ventral attention functional network segregation in older adults

Converging evidence suggests that handgrip strength is linked to cognition in older adults, and this may be subserved by shared age-related changes in brain function and structure. However, the interplay among handgrip strength, brain functional connectivity, and cognitive function remains poorly elucidated. Hence, our study sought to examine these relationships in 148 community-dwelling older adults. Specifically, we examined functional segregation, a measure of functional brain organization sensitive to ageing and cognitive decline, and its associations with handgrip strength and cognitive function. We showed that higher handgrip strength was related to better processing speed, attention, and global cognition. Further, higher handgrip strength was associated with higher segregation of the salience/ventral attention network, driven particularly by higher salience/ventral attention intra-network functional connectivity of the right anterior insula to the left posterior insula/frontal operculum and right midcingulate/medial parietal cortex. Importantly, these handgrip strength-related inter-individual differences in salience/ventral attention network functional connectivity were linked to cognitive function, as revealed by functional decoding and brain-cognition association analyses. Our findings thus highlight the importance of the salience/ventral attention network in handgrip strength and cognition, and suggest that inter-individual differences in salience/ventral attention network segregation and intra-network connectivity could underpin the handgrip strength-cognition relationship in older adults.

Brain gray matter morphometry relates to onset age of bilingualism and theory of mind in young and older adults

Lifelong bilingualism may result in neural reserve against decline not only in the general cognitive domain, but also in social cognitive functioning. In this study, we show the brain structural correlates that are associated with second language age of acquisition (L2AoA) and theory of mind (the ability to reason about mental states) in normal aging. Participants were bilingual adults (46 young, 50 older) who completed a theory-of-mind task battery, a language background questionnaire, and an anatomical MRI scan to obtain cortical morphometric features (i.e., gray matter volume, thickness, and surface area). Findings indicated a theory-of-mind decline in older adults compared to young adults, controlling for education and general cognition. Importantly, earlier L2AoA and better theory-of-mind performance were associated with larger volume, higher thickness, and larger surface area in the bilateral temporal, medial temporal, superior parietal, and prefrontal brain regions. These regions are likely to be involved in mental representations, language, and cognitive control. The morphometric association with L2AoA in young and older adults were comparable, but its association with theory of mind was stronger in older adults than young adults. The results demonstrate that early bilingual acquisition may provide protective benefits to intact theory-of-mind abilities against normal age-related declines.

DeepResBat: deep residual batch harmonization accounting for covariate distribution differences

Pooling MRI data from multiple datasets requires harmonization to reduce undesired inter-site variabilities, while preserving effects of biological variables (or covariates). The popular harmonization approach ComBat uses a mixed effect regression framework that explicitly accounts for covariate distribution differences across datasets. There is also significant interest in developing harmonization approaches based on deep neural networks (DNNs), such as conditional variational autoencoder (cVAE). However, current DNN approaches do not explicitly account for covariate distribution differences across datasets. Here, we provide mathematical results, suggesting that not accounting for covariates can lead to suboptimal harmonization outcomes. We propose two DNN-based harmonization approaches that explicitly account for covariate distribution differences across datasets: covariate VAE (coVAE) and DeepResBat. The coVAE approach is a natural extension of cVAE by concatenating covariates and site information with site- and covariate-invariant latent representations. DeepResBat adopts a residual framework inspired by ComBat. DeepResBat first removes the effects of covariates with nonlinear regression trees, followed by eliminating site differences with cVAE. Finally, covariate effects are added back to the harmonized residuals. Using three datasets from three different continents with a total of 2787 participants and 10085 anatomical T1 scans, we find that DeepResBat and coVAE outperformed ComBat, CovBat and cVAE in terms of removing dataset differences, while enhancing biological effects of interest. However, coVAE hallucinates spurious associations between anatomical MRI and covariates even when no association exists. Therefore, future studies proposing DNN-based harmonization approaches should be aware of this false positive pitfall. Overall, our results suggest that DeepResBat is an effective deep learning alternative to ComBat.

Mindfulness-based therapy improves brain functional network reconfiguration efficiency

Mindfulness-based interventions are showing increasing promise as a treatment for psychological disorders, with improvements in cognition and emotion regulation after intervention. Understanding the changes in functional brain activity and neural plasticity that underlie these benefits from mindfulness interventions is thus of interest in current neuroimaging research. Previous studies have found functional brain changes during resting and task states to be associated with mindfulness both cross-sectionally and longitudinally, particularly in the executive control, default mode and salience networks. However, limited research has combined information from rest and task to study mindfulness-related functional changes in the brain, particularly in the context of intervention studies with active controls. Recent work has found that the reconfiguration efficiency of brain activity patterns between rest and task states is behaviorally relevant in healthy young adults. Thus, we applied this measure to investigate how mindfulness intervention changed functional reconfiguration between rest and a breath-counting task in elderly participants with self-reported sleep difficulties. Improving on previous longitudinal designs, we compared the intervention effects of a mindfulness-based therapy to an active control (sleep hygiene) intervention. We found that mindfulness intervention improved self-reported mindfulness measures and brain functional reconfiguration efficiency in the executive control, default mode and salience networks, though the brain and behavioral changes were not associated with each other. Our findings suggest that neuroplasticity may be induced through regular mindfulness practice, thus bringing the intrinsic functional configuration in participants' brains closer to a state required for mindful awareness.

NEUROCORRELATES BETWEEN THEORY-OF-MIND AND BILINGUALISM IN GRAY MATTER VOLUME OF YOUNG AND OLDER ADULTS

The experience of being bilingual may accrue cognitive reserve against age-related declines in older adults. Early bilingualism, e.g., second language age-of-acquisition (L2AoA), has been shown to be associated with better theory-of-mind (ToM) performance in older adults (Yow et al., 2021). Here, we aim to understand the brain structural correlates associated with bilingualism and ToM performance in normal aging. Forty-six young (YA, aged 19-30, M=21.87) and 51 older adult bilinguals (OA, aged 54-77, M=63.61) completed 1) ToM assessments, where they viewed vignettes and answered questions about the protagonists’ mental states, 2) an anatomical MRI scan, 3) a demographic questionnaire including L2AoA and years of education, and 4) a general cognitive ability assessment by the Montreal Cognitive Assessment (MoCA) test. As expected, ANCOVA on ToM composite scores revealed a significant main effect of age – YA showed better ToM performance than OA, F(1,93)=9.48, p=.003, controlling for education and MoCA scores. Importantly, MRI data were preprocessed to obtain gray matter volume (GMV), proxy of neuronal density, of 430 brain regions. Partial least square correlation analysis identified one significant multivariate pattern linking individual differences in GMV with ToM score and L2AoA (48.7% covariance explained, p=.014). Regardless of age, larger GMV in several regions including prefrontal, frontal, medial temporal, and superior temporal cortices were associated with earlier L2AoA (p=.003) and higher ToM score (p=.004), indicating shared variance between ToM and L2AoA in brain morphology. Findings suggest that earlier bilingual acquisition might promote brain maturation that would preserve ToM ability well into later stages of life.

Stage-dependent differential influence of metabolic and structural networks on memory across Alzheimer's disease continuum

Background

Large-scale neuronal network breakdown underlies memory impairment in Alzheimer's disease (AD). However, the differential trajectories of the relationships between network organisation and memory across pathology and cognitive stages in AD remain elusive. We determined whether and how the influences of individual-level structural and metabolic covariance network integrity on memory varied with amyloid pathology across clinical stages without assuming a constant relationship.

Methods

Seven hundred and eight participants from the Alzheimer's Disease Neuroimaging Initiative were studied. Individual-level structural and metabolic covariance scores in higher-level cognitive and hippocampal networks were derived from magnetic resonance imaging and [18F] fluorodeoxyglucose positron emission tomography using seed-based partial least square analyses. The non-linear associations between network scores and memory across cognitive stages in each pathology group were examined using sparse varying coefficient modelling.

Results

We showed that the associations of memory with structural and metabolic networks in the hippocampal and default mode regions exhibited pathology-dependent differential trajectories across cognitive stages using sparse varying coefficient modelling. In amyloid pathology group, there was an early influence of hippocampal structural network deterioration on memory impairment in the preclinical stage, and a biphasic influence of the angular gyrus-seeded default mode metabolic network on memory in both preclinical and dementia stages. In non-amyloid pathology groups, in contrast, the trajectory of the hippocampus-memory association was opposite and weaker overall, while no metabolism covariance networks were related to memory. Key findings were replicated in a larger cohort of 1280 participants.

Conclusions

Our findings highlight potential windows of early intervention targeting network breakdown at the preclinical AD stage.

Funding

Data collection and sharing for this project was funded by the Alzheimer's Disease Neuroimaging Initiative (ADNI) (National Institutes of Health Grant U01 AG024904) and DOD ADNI (Department of Defense award number W81XWH-12-2-0012). We also acknowledge the funding support from the Duke NUS/Khoo Bridge Funding Award (KBrFA/2019-0020) and NMRC Open Fund Large Collaborative Grant (OFLCG09May0035).

Bilingual language entropy influences executive functions through functional connectivity and signal variability

How bilinguals' experience in managing multiple languages in different communicative contexts influences the cognitive and neural aspects of executive functions remains unclear. Therefore, we examined whether variations in language experience in young adult bilinguals were associated with data-driven brain functional network patterns (connectivity and signal variability) defined by performance during executive control tasks (Stroop and task-switching). Multiple aspects of language experience, such as the extent of balanced bilingualism in language proficiency and usage, and language diversity across social contexts (i.e., language entropy) were assessed. We found that greater language diversity, rather than balanced bilingualism per se, was related to higher brain network specialization and segregation concentrated on the default mode and executive control networks, and lower signal variability, a pattern linked to smaller RT-indices related to executive functioning of shifting, goal-maintenance, and conflict-monitoring. Our findings underscore the important role of language diversity in influencing bilinguals' neurocognitive characteristics of executive functioning.

Brain white matter extracellular free-water increases are related to reduced neurocognitive function in systemic lupus erythematosus

OBJECTIVES

Brain white matter (WM) microstructural changes evaluated by diffusion MRI were well documented in patients with systemic lupus erythematosus (SLE). Yet, conventional diffusion tensor imaging technique fails to differentiate WM changes that originate from tissue alterations from those due to increased extracellular free water (FW) related to neuroinflammation, microvascular disruption, atrophy, or other extracellular processes. Here, we sought to delineate changes in WM tissue microstructure and extracellular FW volume and examine their relationships with neurocognitive function in SLE patients.

METHODS

Twenty SLE patients (16 females, aged 36.0±10.6) without clinically-overt neuropsychiatric manifestation and 61 healthy controls (HC) (29 females, aged 29.2±9.4) underwent diffusion MRI and computerized neuropsychological assessments cross-sectionally. The FW imaging method was applied to compare microstructural tissue changes and extracellular FW volume of the brain WM between SLE patients and HC. Association between extracellular FW changes and neurocognitive performance was studied.

RESULTS

SLE patients had higher WM extracellular FW compared to HC (family-wise-error-corrected p < 0.05) while no group difference was found in FW-corrected tissue compartment and structural connectivity metrics. Extracellular FW increases in SLE patients were associated with poorer neurocognitive performance that probed sustained attention (p = 0.022) and higher cumulative glucocorticoid dose (p = 0.0041). Such findings remained robust after controlling for age, gender, IQ, and total WM volume.

CONCLUSIONS

The association between WM extracellular FW increases and reduced neurocognitive performance suggest possible microvascular degradation and/or neuroinflammation in SLE patients with clinically-inactive disease. The mechanistic impact of cumulative glucocorticoids on WM FW deserves further evaluation.

070 Respiratory, cardiac, EEG, BOLD signals and functional connectivity over multiple microsleep episodes

Introduction

Brief intrusions of unintended sleep can occur in various contexts, for example during resting-state fMRI scans. In addition to changes in neural activity, such microsleep episodes are also associated with shifts in respiration and heartrate. Here we investigated how these concurrent changes alter the dynamics of the BOLD signal in the brain and estimates of functional connectivity.

Methods

Ten participants underwent 6 runs of 20 minute resting-state fMRI scans with concurrent respiration, PPG and EEG recording. Realtime eye-closure monitoring combined with post eye-opening self-reports were used to identify microsleep episodes of different durations.

Results

During microsleep, sustained reductions were observed in arousal as assessed by EEG (ratio of alpha to delta and theta bands), as expected. In comparison, cortical BOLD signal exhibited more complex, temporally multiphasic changes which were consistent across different microsleep durations from 4 to 44s: (i) an initial sleep-onset dip reaching a nadir after ~6s, followed by (ii) an increase above wake baseline that plateaued till awakening. On awakening, (iii) a transient positive bump occurred up to 6s, followed by (iv) an undershoot below baseline lasting ~30s. While seen across the whole brain, these changes showed regional variations, e.g., the signal plateau in the thalamus remained below wake baseline. Sleep onset and awakening were also associated with respective reductions and increases in respiration and heart rate, which affect blood oxygen levels. Brain functional connectivity estimates were altered by the frequency of falling asleep, and this was not resolved by global signal regression.

Conclusion

Falling asleep and awakening are shown here to be associated with large, widespread BOLD signal changes consistent across varied durations of microsleep. These signal changes are intimately intertwined with shifts in respiration and heart rate, which are influenced by common brainstem nuclei controlling sleep. These autonomic contributions to ‘brain signal’ changes at microsleep onset and awakening are integral to sleep, and urge the integration of autonomic and central nervous system contributions to BOLD signal into frameworks for understanding brain function using fMRI. In addition, the correlation between frequency of microsleep and extent of altered functional connectivity highlight the need to minimize sleep during resting state scans.

Support (if any)

NMRC/STaR/015/2013

Respiratory, cardiac, EEG, BOLD signals and functional connectivity over multiple microsleep episodes

Falling asleep is common in fMRI studies. By using long eyelid closures to detect microsleep onset, we showed that the onset and termination of short sleep episodes invokes a systematic sequence of BOLD signal changes that are large, widespread, and consistent across different microsleep durations. The signal changes are intimately intertwined with shifts in respiration and heart rate, indicating that autonomic contributions are integral to the brain physiology evaluated using fMRI and cannot be simply treated as nuisance signals. Additionally, resting state functional connectivity (RSFC) was altered in accord with the frequency of falling asleep and in a manner that global signal regression does not eliminate. Our findings point to the need to develop a consensus among neuroscientists using fMRI on how to deal with microsleep intrusions. SIGNIFICANCE STATEMENT: Sleep, breathing and cardiac action are influenced by common brainstem nuclei. We show that falling asleep and awakening are associated with a sequence of BOLD signal changes that are large, widespread and consistent across varied durations of sleep onset and awakening. These signal changes follow closely those associated with deceleration and acceleration of respiration and heart rate, calling into question the separation of the latter signals as 'noise' when the frequency of falling asleep, which is commonplace in RSFC studies, correlates with the extent of RSFC perturbation. Autonomic and central nervous system contributions to BOLD signal have to be jointly considered when interpreting fMRI and RSFC studies.

Distinct network topology in Alzheimer's disease and behavioral variant frontotemporal dementia

Background

Alzheimer’s disease (AD) and behavioral variant frontotemporal dementia (bvFTD) cause distinct atrophy and functional disruptions within two major intrinsic brain networks, namely the default network and the salience network, respectively. It remains unclear if inter-network relationships and whole-brain network topology are also altered and underpin cognitive and social–emotional functional deficits.

Methods

In total, 111 participants (50 AD, 14 bvFTD, and 47 age- and gender-matched healthy controls) underwent resting-state functional magnetic resonance imaging (fMRI) and neuropsychological assessments. Functional connectivity was derived among 144 brain regions of interest. Graph theoretical analysis was applied to characterize network integration, segregation, and module distinctiveness (degree centrality, nodal efficiency, within-module degree, and participation coefficient) in AD, bvFTD, and healthy participants. Group differences in graph theoretical measures and empirically derived network community structures, as well as the associations between these indices and cognitive performance and neuropsychiatric symptoms, were subject to general linear models, with age, gender, education, motion, and scanner type controlled.

Results

Our results suggested that AD had lower integration in the default and control networks, while bvFTD exhibited disrupted integration in the salience network. Interestingly, AD and bvFTD had the highest and lowest degree of integration in the thalamus, respectively. Such divergence in topological aberration was recapitulated in network segregation and module distinctiveness loss, with AD showing poorer modular structure between the default and control networks, and bvFTD having more fragmented modules in the salience network and subcortical regions. Importantly, aberrations in network topology were related to worse attention deficits and greater severity in neuropsychiatric symptoms across syndromes.

Conclusions

Our findings underscore the reciprocal relationships between the default, control, and salience networks that may account for the cognitive decline and neuropsychiatric symptoms in dementia.

Degeneration of structural brain networks is associated with cognitive decline after ischaemic stroke

Over one-third of stroke patients has long-term cognitive impairment. The likelihood of cognitive dysfunction is poorly predicted by the location or size of the infarct. The macro-scale damage caused by ischaemic stroke is relatively localized, but the effects of stroke occur across the brain. Structural covariance networks represent voxelwise correlations in cortical morphometry. Atrophy and topographical changes within such distributed brain structural networks may contribute to cognitive decline after ischaemic stroke, but this has not been thoroughly investigated. We examined longitudinal changes in structural covariance networks in stroke patients and their relationship to domain-specific cognitive decline. Seventy-three patients (mean age, 67.41 years; SD = 12.13) were scanned with high-resolution magnetic resonance imaging at sub-acute (3 months) and chronic (1 year) timepoints after ischaemic stroke. Patients underwent a number of neuropsychological tests, assessing five cognitive domains including attention, executive function, language, memory and visuospatial function at each timepoint. Individual-level structural covariance network scores were derived from the sub-acute grey-matter probabilistic maps or changes in grey-matter probability maps from sub-acute to chronic using data-driven partial least squares method seeding at major nodes in six canonical high-order cognitive brain networks (i.e. dorsal attention, executive control, salience, default mode, language-related and memory networks). We then investigated co-varying patterns between structural covariance network scores within canonical distributed brain networks and domain-specific cognitive performance after ischaemic stroke, both cross-sectionally and longitudinally, using multivariate behavioural partial least squares correlation approach. We tested our models in an independent validation data set with matched imaging and behavioural testing and using split-half validation. We found that distributed degeneration in higher-order cognitive networks was associated with attention, executive function, language, memory and visuospatial function impairment in sub-acute stroke. From the sub-acute to the chronic timepoint, longitudinal structural co-varying patterns mirrored the baseline structural covariance networks, suggesting synchronized grey-matter volume decline occurred within established networks over time. The greatest changes, in terms of extent of distributed spatial co-varying patterns, were in the default mode and dorsal attention networks, whereas the rest were more focal. Importantly, faster degradation in these major cognitive structural covariance networks was associated with greater decline in attention, memory and language domains frequently impaired after stroke. Our findings suggest that sub-acute ischaemic stroke is associated with widespread degeneration of higher-order structural brain networks and degradation of these structural brain networks may contribute to longitudinal domain-specific cognitive dysfunction.

Distinct BOLD variability changes in the default mode and salience networks in Alzheimer's disease spectrum and associations with cognitive decline

Optimal levels of intrinsic Blood-Oxygenation-Level-Dependent (BOLD) signal variability (variability hereafter) are important for normative brain functioning. However, it remains largely unknown how network-specific and frequency-specific variability changes along the Alzheimer's disease (AD) spectrum and relates to cognitive decline. We hypothesized that cognitive impairment was related to distinct BOLD variability alterations in two brain networks with reciprocal relationship, i.e., the AD-specific default mode network (DMN) and the salience network (SN). We examined variability of resting-state fMRI data at two characteristic slow frequency-bands of slow4 (0.027-0.073 Hz) and slow5 (0.01-0.027 Hz) in 96 AD, 98 amnestic mild cognitive impairment (aMCI), and 48 age-matched healthy controls (HC) using two commonly used pre-processing pipelines. Cognition was measured with a neuropsychological assessment battery. Using both global signal regression (GSR) and independent component analysis (ICA), results generally showed a reciprocal DMN-SN variability balance in aMCI (vs. AD and/or HC), although there were distinct frequency-specific variability patterns in association with different pre-processing approaches. Importantly, lower slow4 posterior-DMN variability correlated with poorer baseline cognition/smaller hippocampus and predicted faster cognitive decline in all patients using both GSR and ICA. Altogether, our findings suggest that reciprocal DMN-SN variability balance in aMCI might represent an early signature in neurodegeneration and cognitive decline along the AD spectrum.

Amyloid and cerebrovascular burden divergently influence brain functional network changes over time

Objective

To examine the effects of baseline Alzheimer disease and cerebrovascular disease markers on longitudinal default mode network (DMN) and executive control network (ECN) functional connectivity (FC) changes in mild cognitive impairment (MCI).

Methods

We studied 30 patients with amnestic MCI (aMCI) and 55 patients with subcortical vascular MCI (svMCI) with baseline Pittsburgh Compound B (PiB)–PET scans and longitudinal MRI scans. Participants were followed up clinically with annual MRI for up to 4 years (aMCI: 26 with 2 timepoints, 4 with 3 timepoints; svMCI: 13 with 2 timepoints, 16 with 3 timepoints, 26 with 4 timepoints).

Results

β-Amyloid (Aβ) burden was associated with longitudinal DMN FC declines, while cerebrovascular burden was associated with longitudinal ECN FC changes. When patients were divided into PiB+ and PiB− groups, PiB+ patients showed longitudinal DMN FC declines, while patients with svMCI showed longitudinal ECN FC increases. Direct comparisons between the 2 groups without mixed pathology (aMCI PiB+ and svMCI PiB−) recapitulated this divergent pattern: aMCI PiB+ patients showed steeper longitudinal DMN FC declines, while svMCI PiB− patients showed steeper longitudinal ECN FC increases. Finally, using baseline PiB uptake and lacune numbers as continuous variables, baseline PiB uptake showed inverse U-shape associations with longitudinal DMN FC changes in both MCI subtypes, while baseline lacune numbers showed mainly inverse U-shape relationships with longitudinal ECN FC changes in patients with svMCI.

Conclusions

Our findings underscore the divergent effects of Aβ and cerebrovascular burden on longitudinal FC changes in the DMN and ECN in the predementia stage, which reflect the underlying pathology and may be used to track early changes in Alzheimer disease and cerebrovascular disease.

Amyloid burden accelerates white matter degradation in cognitively normal elderly individuals

Alterations in parietal and temporal white matter microstructure derived from diffusion tensor imaging occur in preclinical and clinical Alzheimer's disease. Amyloid beta (Aβ) deposition and such white matter alterations are two pathological hallmarks of Alzheimer's disease. However, the relationship between these pathologies is not yet understood, partly since conventional diffusion MRI methods cannot distinguish between cellular and extracellular processes. Thus, we studied Aβ-associated longitudinal diffusion MRI changes in Aβ-positive (N = 21) and Aβ-negative (N = 51) cognitively normal elderly obtained from the Alzheimer's Disease Neuroimaging Initiative dataset using linear mixed models. Aβ-positivity was based on Alzheimer's Disease Neuroimaging Initiative amyloid-PET recommendations using a standardized uptake value ratio cut-off of 1.11. We used free-water imaging to distinguish cellular and extracellular changes. We found that Aβ-positive subjects had increased baseline right uncinate fasciculus free-water fraction (FW), associated with worse baseline Alzheimer's disease assessment scale scores. Furthermore, Aβ-positive subjects showed faster decrease in fractional anisotropy (FW-corrected) in the right uncinate fasciculus and faster age-dependent right inferior longitudinal fasciculus FW increases over time. Right inferior longitudinal fasciculus FW increases were associated with greater memory decline. Importantly, these results remained significant after controlling for gray and white matter volume and hippocampal volume. This is the first study to illustrate the influence of Aβ burden on early longitudinal (in addition to baseline) white matter changes in cognitively normal elderly individuals at-risk of Alzheimer's disease, thus underscoring the importance of longitudinal studies in assessing microstructural alterations in individuals at risk of Alzheimer's disease prior to symptoms onset.

Alterations in Brain Network Topology and Structural-Functional Connectome Coupling Relate to Cognitive Impairment

According to the network-based neurodegeneration hypothesis, neurodegenerative diseases target specific large-scale neural networks, such as the default mode network, and may propagate along the structural and functional connections within and between these brain networks. Cognitive impairment no dementia (CIND) represents an early prodromal stage but few studies have examined brain topological changes within and between brain structural and functional networks. To this end, we studied the structural networks [diffusion magnetic resonance imaging (MRI)] and functional networks (task-free functional MRI) in CIND (61 mild, 56 moderate) and healthy older adults (97 controls). Structurally, compared with controls, moderate CIND had lower global efficiency, and lower nodal centrality and nodal efficiency in the thalamus, somatomotor network, and higher-order cognitive networks. Mild CIND only had higher nodal degree centrality in dorsal parietal regions. Functional differences were more subtle, with both CIND groups showing lower nodal centrality and efficiency in temporal and somatomotor regions. Importantly, CIND generally had higher structural-functional connectome correlation than controls. The higher structural-functional topological similarity was undesirable as higher correlation was associated with poorer verbal memory, executive function, and visuoconstruction. Our findings highlighted the distinct and progressive changes in brain structural-functional networks at the prodromal stage of neurodegenerative diseases.

Compulsory Admission in Hong Kong: Balance between Paternalism and Patient Liberty

In Hong Kong, compulsory admission is governed by the Mental Health Ordinance Section 31 (detention of a patient under observation), Section 32 (extension of period of detention for such a patient), Section 36 (detention of certified patients), and the sections in Part IV for hospital order, transfer order, and removal order. Mental health professionals adopt both legal criteria and practice criteria for compulsory admission. The present study discusses the harm principle, the patient's decision-making capacity, the multi-axial framework for compulsory admission, and the balance between paternalism and patient liberty.

The impact of music guided deep breathing exercise on blood pressure control - A participant blinded randomised controlled study

INTRODUCTION

As pharmacological treatment of hypertension has become a burden worldwide, the study looked into nonpharmacological ways of reducing blood pressure. The objective was to determine if music guided, slow and deep breathing will reduce the blood pressure among patients with hypertension in eight weeks.

METHODS

A participant blinded, multi-centre, randomised controlled trial was conducted in which the participants in the intervention group (IG) practiced deep breathing exercise guided by sound cues and those in the control group (CG) listened to the music. The primary end point was reduction in blood pressure at eight weeks.

RESULTS

87 patients, 46 males and 41 females with mean age of 61.1 years were recruited and 93.1% of them successfully completed the study. There was significant reduction in systolic and diastolic Blood Pressure from baseline by 8 weeks in both groups. The reduction in Mean systolic blood pressure (SBP) in the control arm was 10.5mmHg compared to 8.3mmHg (p<0.001) in intervention group. Diastolic blood pressure (DBP) reduction in control and intervention groups were 5.2 mmHg (p<0.001) and 5.6 mmHg (p<0.001) respectively. The absolute difference in SBP reduction from baseline in IG & CG was -2.2 (95%CI: -7.8 to 3.5) and DBP was -0.4 (95%CI: -2.9 to 3.6). However, blood pressure reduction between the two groups was not significant.

CONCLUSIONS

Both listening to music and deep breathing exercise were associated with a clinically significant reduction in SBP and DBP. However, deep breathing exercise did not augment the benefit of music in reducing BP.

Functional segregation loss over time is moderated by APOE genotype in healthy elderly

We investigated the influence of the apolipoprotein E-ɛ4 allele (APOE-ɛ4) on longitudinal age-related changes in brain functional connectivity (FC) and cognition, in view of mixed cross-sectional findings. One hundred and twenty-two healthy older adults (aged 58-79; 25 APOE-ɛ4 carriers) underwent task-free fMRI scans at baseline. Seventy-eight (16 carriers) had at least one follow-up (every 2 years). Changes in intra- and internetwork FCs among the default mode (DMN), executive control (ECN), and salience (SN) networks, as well as cognition, were quantified using linear mixed models. Cross-sectionally, APOE-ɛ4 carriers had lower functional connectivity between the ECN and SN than noncarriers. Carriers also showed a stronger age-dependent decrease in visuospatial memory performance. Longitudinally, carriers had steeper increase in inter-ECN-DMN FC, indicating loss of functional segregation. The longitudinal change in processing speed performance was not moderated by APOE-ɛ4 genotype, but the brain-cognition association was. In younger elderly, faster loss of segregation was correlated with greater decline in processing speed regardless of genotype. In older elderly, such relation remained for noncarriers but reversed for carriers. APOE-ɛ4 may alter aging by accelerating the change in segregation between high-level cognitive systems. Its modulation on the longitudinal brain-cognition relationship was age-dependent.

Validation of the "Security Needs Assessment Profile" for measuring the profiles of security needs of Chinese forensic psychiatric inpatients

Mapping forensic psychiatric services with the security needs of patients is a salient step in service planning, audit and review. A valid and reliable instrument for measuring the security needs of Chinese forensic psychiatric inpatients was not yet available. This study aimed to develop and validate the Chinese version of the Security Needs Assessment Profile for measuring the profiles of security needs of Chinese forensic psychiatric inpatients. The Security Needs Assessment Profile by Davis was translated into Chinese. Its face validity, content validity, construct validity and internal consistency reliability were assessed by measuring the security needs of 98 Chinese forensic psychiatric inpatients. Principal factor analysis for construct validity provided a six-factor security needs model explaining 68.7% of the variance. Based on the Cronbach's alpha coefficient, the internal consistency reliability was rated as acceptable for procedural security (0.73), and fair for both physical security (0.62) and relational security (0.58). A significant sex difference (p=0.002) in total security score was found. The Chinese version of the Security Needs Assessment Profile is a valid and reliable instrument for assessing the security needs of Chinese forensic psychiatric inpatients.

Differential age-dependent associations of gray matter volume and white matter integrity with processing speed in healthy older adults

Slower processing speed (PS), a highly robust feature of cognitive aging, is associated with white matter (WM) deterioration and gray matter volume (GMV) loss. Traditional linear regression models assume a constant relationship between brain structure and cognition over time. To probe for variation in the association between WM and GMV and PS over time, we used a novel sparse varying coefficient model on data collected from 126 relatively healthy older adults (67 females, aged 58-85years) evaluated with MRI and a standardized neuropsychological test-battery. We found that WM microstructural differences indexed by fractional anisotropy values in the fronto-striatal tracts (internal and external capsule) showed a stronger association with PS before the age of 70years. Contrastingly, GMV values of the left putamen and middle occipital gyrus were more strongly correlated with PS after 70years. Additionally, within GM and WM compartments, there was heterogeneity in the temporal sequence in which different cortical and subcortical elements were most strongly associated with PS. Together, these observations provide a more nuanced account of the relationships between different structural components of the aging brain and processing speed, a key cognitive domain affected in relatively healthy older adults.

The interplay between the anticipation and subsequent online processing of emotional stimuli as measured by pupillary dilatation: the role of cognitive reappraisal

Emotions can occur during an emotion-eliciting event, but they can also arise when anticipating the event. We used pupillary responses, as a measure of effortful cognitive processing, to test whether the anticipation of an emotional stimulus (positive and negative) influences the subsequent online processing of that emotional stimulus. Moreover, we tested whether individual differences in the habitual use of emotion regulation strategies are associated with pupillary responses during the anticipation and/or online processing of this emotional stimulus. Our results show that, both for positive and negative stimuli, pupillary diameter during the anticipation of emotion-eliciting events is inversely and strongly correlated to pupillary responses during the emotional image presentation. The variance in this temporal interplay between anticipation and online processing was related to individual differences in emotion regulation. Specifically, the results show that high reappraisal scores are related to larger pupil diameter during the anticipation which is related to smaller pupillary responses during the online processing of emotion-eliciting events. The habitual use of expressive suppression was not associated to pupillary responses in the anticipation and subsequent online processing of emotional stimuli. Taken together, the current data suggest (most strongly for individuals scoring high on the habitual use of reappraisal) that larger pupillary responses during the anticipation of an emotional stimulus are indicative of a sustained attentional set activation to prepare for an upcoming emotional stimulus, which subsequently directs a reduced need to cognitively process that emotional event. Hence, because the habitual use of reappraisal is known to have a positive influence on emotional well-being, the interplay between anticipation and online processing of emotional stimuli might be a significant marker of this well-being.

Phase I study of weekly nab-paclitaxel + weekly cetuximab + intensity-modulated radiation therapy (IMRT) in patients with stage III-IVB head and neck squamous cell carcinoma (HNSCC)

BACKGROUND

There is a clinical need to improve the efficacy of standard cetuximab + concurrent intensity-modulated radiation therapy (IMRT) for patients with locally and/or regionally advanced HNSCC. Taxanes have radiosensitizing activity against HNSCC, and nab-paclitaxel may offer therapeutic advantage in comparison with other taxanes.

PATIENTS AND METHODS

This was a single-institution phase I study with a modified 3 + 3 design. Four dose levels (DLs) of weekly nab-paclitaxel were explored (30, 45, 60, and 80 mg/m(2)), given with standard weekly cetuximab (450 mg/m(2) loading dose followed by 250 mg/m(2) weekly) and concurrent IMRT (total dose, 70 Gy).

RESULTS

Twenty-five eligible patients (20 M, 5 F) enrolled, with median age 58 years (range, 46-84 years). Primary tumor sites were oropharynx, 19 (10 human papillomavirus [HPV] pos, 8 HPV neg, 1 not done); neck node with unknown primary, 2; larynx 2; and oral cavity and maxillary sinus, 1 each. Seven patients had received prior induction chemotherapy. Maximum tolerated dose (MTD) was exceeded at DL4 (nab-paclitaxel, 80 mg/m(2)) with three dose-limiting toxicities (DLTs) (grade 3 neuropathy, grade 3 dehydration, with grade 3 mucositis grade 3 anemia) among five assessable patients. There was only one DLT (grade 3 supraventricular tachycardia) among six patients at DL3 (nab-paclitaxel, 60 mg/m(2)), and this was deemed the MTD. Among 23 assessable patients, the most common ≥ g3 AEs were lymphopenia 100%, functional mucositis 65%, and pain in throat/oral cavity 52%. At a median follow-up of 33 months, 2-year failure-free survival (FFS) is 65% [95% confidence interval (CI) 42% to 81%] and 2-year overall survival (OS) is 91% (95% CI 69-97).

CONCLUSION

The recommended phase II dose for nab-paclitaxel is 60 mg/m(2) weekly when given standard weekly cetuximab and concurrent IMRT. This regimen merits further study as a nonplatinum alternative to IMRT + cetuximab alone.

CLINICALTRIALSGOV ID

NCT00736619.

Distractor Expectancy Effects on Interval Timing

The influence of non-temporal distractor stimuli on interval timing under conditions expected to elicit covert shifts of attention was examined using seconds range stimuli and the duration bisection task. Distractor stimuli appeared in positions peripheral to the timing signal on half of the trials, but participants were instructed to maintain fixation on the timing stimulus while their eye positions were monitored using an eye-tracker. In Experiment 1, participants ignored the distractors, whereas in Experiment 2 participants counted the distractors. In both experiments, trials with distractors were judged as longer than equivalent duration trials without distractors. Presenting a cue that indicated whether or not the subsequent trial would include distractors (Experiment 3) eliminated this lengthening effect. Taken together, these results suggest that when the presence of distractor stimuli during a trial is uncertain, distractor expectation captures attention that would otherwise be allocated to timing, with the result that perceived duration is shorter on trials in which distractors are absent.

Community-based cardiovascular Risk Factors Intervention Strategies (CORFIS) in managing hypertension: A pragmatic non-randomised controlled trial

BACKGROUND

Hypertension is the number one cardiovascular risk factor in Malaysia. This study aimed to evaluate the effectiveness of a Community-Based Cardiovascular Risk Factors Intervention Strategies (CORFIS) in the management of hypertension in primary care.

METHODS

This is a pragmatic, non-randomized controlled trial. Seventy general practitioners (GPs) were selected to provide either CORFIS (44 GPs) or conventional care (26 GPs) for 6 months. A total of 486 hypertensive patients were recruited; 309 were in the intervention and 177 in the control groups. Primary outcome was the proportion of hypertensive patients who achieved target blood pressure (BP) of <140/90mmHg (for those without diabetes mellitus) and <130/80mmHg (with diabetes mellitus). Secondary outcomes include change in the mean/median BP at 6-month as compared to baseline.

RESULTS

The proportion of hypertensive patients who achieved target BP at 6-month was significantly higher in the CORFIS arm (69.6%) as compared to the control arm (57.6%), P=0.008. Amongst those who had uncontrolled BP at baseline, the proportion who achieved target BP at 6-month was also significantly higher in the CORFIS arm (56.6%) as compared to the control arm (34.1%), p<0.001. There was no difference in the patients who had already achieved BP control at baseline. There were significant reductions in SBP in the CORFIS arm (median -9.0mmHg; -60 to 50) versus control (median -2mmHg; -50 to 48), p=0.003; as well as in DBP (CORFIS arm: median -6.0mmHg; ranged from -53 to 30 versus control arm: median 0.0mmHg; ranged from -42 to 30), p<0.001.

CONCLUSIONS

Patients who received CORFIS care demonstrated significant improvements in achieving target BP.

Long-term disease-free survival in three ovarian cancer patients with a single relapse

Recurrent ovarian cancer with long-term survival is uncommon and often associated with poor prognosis. We report three cases of patients with advanced ovarian cancer who have achieved long-term disease-free survival following a single prior relapse. Case 1 relapsed with a localized bulky tumor and received a complete surgical resection and chemotherapy. Case 2 had a persistent central pelvic tumor after debulking surgery and second-line chemotherapy, and yet achieved excellent control with concurrent chemoradiation to the true pelvis. Case 3 relapsed with paraaortic lymph node metastasis and probable lung metastasis (subsequently negated by positron emission tomography) and received chemotherapy alone. These three patients have since remained disease-free for 13, 12, and seven years, respectively, since their first relapse. We conclude that select patients can obtain long-term disease-free survival after the first relapse by accurate restaging and aggressive multimodality treatment.

Contingent negative variation and its relation to time estimation: a theoretical evaluation

The relation between the contingent negative variation (CNV) and time estimation is evaluated in terms of temporal accumulation and preparation processes. The conclusion is that the CNV as measured from the electroencephalogram (EEG) recorded at fronto-central and parietal-central areas is not a direct reflection of the underlying interval timing mechanism(s), but more likely represents a time-based response preparation/decision-making process.

Temporal accumulation and decision processes in the duration bisection task revealed by contingent negative variation

The duration bisection paradigm is a classic task used to examine how humans and other animals perceive time. Typically, participants first learn short and long anchor durations and are subsequently asked to classify probe durations as closer to the short or long anchor duration. However, the specific representations of time and the decision rules applied in this task remain the subject of debate. For example, researchers have questioned whether participants actually use representations of the short and long anchor durations in the decision process rather than merely a response threshold that is derived from those anchor durations. Electroencephalographic (EEG) measures, like the contingent negative variation (CNV), can provide information about the perceptual and cognitive processes that occur between the onset of the timing stimulus and the motor response. The CNV has been implicated as an electrophysiological marker of interval timing processes such as temporal accumulation, representation of the target duration, and the decision that the target duration has been attained. We used the CNV to investigate which durations are involved in the bisection categorization decision. The CNV increased in amplitude up to the value of the short anchor, remained at a constant level until about the geometric mean (GM) of the short and long anchors, and then began to resolve. These results suggest that the short anchor and the GM of the short and long anchors are critical target durations used in the bisection categorization decision process. In addition, larger mean N1P2 amplitude differences were associated with larger amplitude CNVs, which may reflect the participant’s precision in initiating timing on each trial across a test session. Overall, the results demonstrate the value of using scalp-recorded EEG to address basic questions about interval timing.

Faecal occult blood screening: knowledge, attitudes, and practice in four Hong Kong primary care clinics

OBJECTIVES. To assess primary care patients for their awareness, knowledge, and attitude towards colorectal cancer and screening, to report on the uptake of faecal occult blood test screening and the results of screening, and explore predictors of screening uptake. DESIGN. Cross-sectional study. SETTING. Four primary care clinics in Hong Kong. PATIENTS. A total of 1664 patients aged 50 to 74 years attending the clinics in the period July 2006 to July 2007. MAIN OUTCOME MEASURES. Percentage of subjects who were aware that colorectal cancer is common and curable at an early stage, and who knew that faecal occult blood test or colonoscopy is useful for screening; relevant knowledge score; uptake rate of faecal occult blood testing; rate of testing positive; and factors predicting uptake. RESULTS. A total of 1645 questionnaires were collected. In all, 89% (95% confidence interval, 88-91%) were aware that colorectal cancer is common, 95% (94-96%) believed faecal occult blood test and colonoscopy are useful for screening, and 58% (56-61%) achieved a knowledge score of 50% or above. The uptake rate of the faecal occult blood test was 35%. Uptake was higher among those with a positive family history (odds ratio=1.57; 95% confidence interval, 1.08-2.27; P=0.02), those who were more aware that colorectal cancer is common (1.86; 1.29-2.69; P=0.001), and that colorectal cancer is potentially curable at an early stage (1.76; 1.32-2.36; P=0.0001). Rate of testing positive was 2.1% (95% confidence interval, 0.9-3.3%); no colorectal cancer was detected and the neoplasia detection rate (for cancers and adenomas) was 5.1 per 1000 subjects screened. CONCLUSIONS. Patients were aware that colorectal cancer is common in our community, and faecal occult blood test or colonoscopy is useful for screening. The uptake of screening was low, though relatively higher for those with a positive family history and greater awareness of the high frequency and potential for cure of colorectal cancer. Faecal occult blood test positivity rate was 2.1%, and neoplasia detection rate 5.1 per 1000 screened.

PlasmaKinetic™ (bipolar) transurethral resection of prostate: a prospective trial to study pathological artefacts, surgical parameters and clinical outcomes

INTRODUCTION

The aims of the study were to compare the degree of cautery artefacts in prostatic chips between monopolar and PlasmaKinetic™ transurethral resection of prostate (TURP), and to determine if there is any difference in the intraoperative and post surgical parameters between them.

METHODS

After institutional review board approval, patients were prospectively enrolled to undergo PlasmaKinetic™ TURP. Their parameters were compared with those of the historical monopolar TURP controls. All histological specimens were reviewed by a single senior pathologist.

RESULTS

46 patients were recruited to undergo PlasmaKinetic™ TURP. The resection time was significantly longer for the bipolar group compared to the monopolar group (50.2 versus 36.7 min, p-value is 0.001). The speed of resection (resection weight/time) was lower for the bipolar group (0.45 versus 0.56 g/min, p-value is 0.017). More irrigant was used for the bipolar group (21.2 versus 15.6 litres, p-value is 0.001) intraoperatively. There was no statistically significant difference in terms of intraoperative drop in haemoglobin and serum sodium change between the two groups. There seems to be a lesser degree of cautery artefacts in the PlasmaKinetic™ group than the monopolar group (42.17 versus 45.07 microns); however, this was not statistically significant (p-value is 0.452).

CONCLUSION

Bipolar TURP seems to result in a lesser degree of cautery artefacts when compared to conventional monopolar TURP, albeit statistically insignificant, compared to monopolar TURP. TURP also resulted in a longer resection time and increased irrigant use, but no difference in blood loss and serum sodium levels.

A qualitative study on HPV vaccination from a nursing perspective in Hong Kong

OBJECTIVE

To identify the perception on human papillomavirus (HPV) vaccination among female nursing students in Hong Kong.

DATA SOURCES

Data were collected through focus group discussions and semi-structured in-depth interviews. All participants (n=28) were female nursing students of a university in Hong Kong. Tape recordings of individual interviews and focus group discussions were transcribed verbatim in Chinese, translated into English, and analyzed according to Colaizzi's phenomenological analysis.

STUDY DESIGN

Four major themes emerged from the data: nursing students' understanding about HPV vaccine, nursing students' attitude on HPV vaccine, nursing students' perspective on HPV vaccination promotion, and nursing role on HPV vaccination.

CONCLUSIONS

Government should take initiative in promotion with vaccine suppliers. The awareness and knowledge of HPV and HPV vaccination among women should be increased in order to raise the positive attitude of women towards HPV vaccination and prevention of cervical cancer. Health professionals should work together on HPV promotion among women and increase the HPV vaccination rates. Moreover, further studies regarding attitude and awareness of HPV vaccination among women in different age groups are needed in order to identify more associated factors affecting their perceptions towards HPV vaccination.

Impact of postoperative complications on long-term outcome of curative resection for hepatocellular carcinoma

BACKGROUND

The aim of this retrospective study was to determine the impact of postoperative complications on the long-term outcome of curative liver resection for hepatocellular carcinoma (HCC).

METHODS

A total of 863 patients who had curative resection of HCC from December 1989 to December 2004 were included in the analysis. Median follow-up was 35.6 months.

RESULTS

Some 288 patients (33.4 per cent) developed postoperative complications. The hospital mortality rate was 5.3 per cent (46 patients). Multiple logistic regression analysis showed that older age and massive intraoperative blood loss were related to a significantly higher complication rate. Demographics of patients with and without postoperative complications were comparable. The former had significantly more blood loss (median 1.1 versus 0.7 litres; P < 0.001) and required more transfused blood (P < 0.001). The overall survival rates of patients without complications at 1, 3, 5 and 10 years were 83.6, 62.8, 51.5 and 32.1 per cent respectively. Corresponding rates for those with complications were 67.8, 52.4, 41.5 and 26.6 per cent (P = 0.004). Cox proportional hazard model analysis revealed that the presence of postoperative complications was independently associated with poor overall survival.

CONCLUSION

Postoperative complications can affect overall long-term survival after resection of HCC.

Efficacy and safety of radiofrequency ablation for perivascular hepatocellular carcinoma without hepatic inflow occlusion

BACKGROUND

The role of radiofrequency ablation (RFA) for perivascular (up to 5 mm from the major intrahepatic portal vein or hepatic vein branches) hepatocellular carcinoma (HCC) is unclear because of possible incomplete tumour ablation and potential vascular damage. This study aimed to evaluate the safety and efficacy of RFA for perivascular HCC without hepatic inflow occlusion.

METHODS

Between May 2001 and November 2003, RFA using an internally cooled electrode was performed on 52 patients with perivascular HCC (group 1) through open (n = 39), percutaneous (n = 9), laparoscopic (n = 2) and thoracoscopic (n = 2) approaches. Hepatic inflow occlusion was not applied during the ablation procedure. The perioperative and postoperative outcomes were compared with those of 90 patients with non-perivascular HCC (group 2) treated by RFA during the same period.

RESULTS

The morbidity rate was similar between groups 1 and 2 (25 versus 28 per cent; P = 0.844). One patient in group 1 (2 per cent) and two in group 2 (2 per cent) had developed thrombosis of major intrahepatic blood vessels on follow-up computed tomography scan. There were no significant differences between groups 1 and 2 in mortality rate (2 versus 0 per cent; P = 0.366), complete ablation rate for small HCC (92 versus 98 per cent; P = 0.197), local recurrence rate (11 versus 9 per cent; P = 0.762) and overall survival (1-year: 86 versus 87 per cent; 2-year: 75 versus 75 per cent; P = 0.741).

CONCLUSION

RFA without hepatic inflow occlusion is a safe and effective treatment for perivascular HCC.

Epidemiological study of diabetic retinopathy in a primary care setting in Hong Kong

OBJECTIVES

To estimate the prevalence and risk factors of diabetic retinopathy in type 2 diabetic patients, and to investigate the difference in retinopathy progression in patients with normal fundi or established retinopathy at baseline and the risk factors implicated in the progression.

DESIGN

Retrospective community-based study.

SETTING

Ten primary care clinics in Hong Kong.

PATIENTS

Type 2 diabetic patients; subsidiary analysis included subjects with more than one screening event.

MAIN OUTCOME MEASURES

Patient demographics, baseline prevalence, and risk factors of diabetic retinopathy; progression of retinopathy in patients with normal fundi and established retinopathy at baseline, and the associated risk factors.

RESULTS

A total of 6165 patients were recruited from January 1998 to May 2004. Primary analysis included 4423 patients with good-quality retinal photographs. The mean age of the patients was 60.36 years (standard deviation, 10.80 years; range, 28-94 years), the mean duration of diabetes was 4.71 years (standard deviation, 4.67 years; range, 0.1-40.6 years), and the mean level of glycated haemoglobin was 7.47% (standard deviation, 1.44%). The prevalence of retinopathy at baseline was 28.4%. Subsidiary analysis showed progression to sight-threatening retinopathy was more common in the group with baseline retinopathy than that without (7.9% vs 0.7%), and occurred at a faster rate (mean, 1.5 [range, 0.5-3.0] vs 2.0 [1.0-4.2] years). Logistic regression revealed that the level of glycated haemoglobin was positively associated with both the onset (P<0.001) and progression of retinopathy (P=0.03).

CONCLUSION

Optimal glycaemic control is important for reducing sight-threatening retinopathy. Close observation is required for patients with established retinopathy as progression occurs more rapidly.

False-positive fluorine-18 fluorodeoxy-D-glucose positron emission tomography imaging caused by retained gauze in a woman with recurrent ovarian cancer: a case report

We report a case of a 47-year-old woman with a false-positive [18F]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) result caused by retained gauze during resection of liver metastasis for a Stage IV ovarian cancer at primary cytoreductive surgery. She achieved complete remission and remained free of progression for seven years. Owing to elevation of CA-125, computed tomography and PET studies were performed, and both showed two potentially resectable lesions. One was located ventral to the diaphragmatic surface of the left hepatic lobe and the other was around the gauze at the right hepatorenal fossa. During surgical intervention, the left supraheptic tumor was excised and the gauze with surrounding granulation was removed. However, the former proved to be recurrent ovarian cancer with the latter proven false-positive. This case demonstrates that PET results should be interpreted with caution in differentiating a benign inflammatory process from malignant abnormalities, especially in regions with a high probability of granulomatous lesions.

Combined hepatocellular-cholangiocarcinoma: a case report

Combined hepatocellular-cholangiocarcinoma (HCC-CC) is a rare primary liver tumour. We report a carrier of both HBV and HCV presenting with intermittent abdominal pain, fever, chillness and elevated á-fetoprotein (AFP) of 1197 ng/ml. Computed tomography showed an irregular hypodense mass in the left lateral segment of the liver with vague contrast enhancement and multiple regional lymphadenopathy. Hepatic angiogram showed that the mass was hypovascular and the left portal vein was occluded with a tapered end. Percutaneous ultrasound-guided core needle biopsy of the liver yielded HCC-CC. We suggest that HCC-CC should be considered in hypovascular liver tumours with striking elevation of serum AFP and multiple regional lymphadenopathy.

The prevalence of microalbuminuria among patients with type II diabetes mellitus in a primary care setting: cross-sectional study

OBJECTIVES

To determine the prevalence of microalbuminuria among patients with type II diabetes mellitus in a primary care setting, and to study the association between various risk factors and the presence of microalbuminuria.

DESIGN

Cross-sectional community-based study.

SETTING

Four primary care clinics, Hong Kong.

PATIENTS

All patients with type II diabetes mellitus who regularly attended the clinics between May 2002 and March 2003.

MAIN OUTCOME MEASURES

Patients' demographic data, the proportion with microalbuminuria (measured using a spot urine test), and the association between this condition and risk factors for diabetic nephropathy (via correlation and multivariable logistic regression analysis).

RESULTS

The mean age of the 1161 patients in the sample population was 58.0 years. The mean duration of diabetes mellitus was 5.7 years, and the mean level of glycated haemoglobin was 7.4%. A total of 13.4% of the patients had microalbuminuria. Having the condition was significantly associated with advanced age, female sex, poor glycaemic control, and coexisting hypertension in both correlation and regression analyses. No significant association with ever smoking was found.

CONCLUSION

Early screening for incipient diabetic nephropathy and aggressive management of modifiable risk factors in a primary care setting may be important in optimising the renal outcome of patients with type II diabetes mellitus.

Sperm output of older men

BACKGROUND

Declining fertility of couples from the fourth decade of life is largely attributable to the drop in female fertility. However, increasing numbers of men, whose fertility theoretically lasts until death, are seeking fertility treatment at older ages, yet there is little information on sperm production and function past the age of 50 years. The few studies of such older men have examined men attending fertility clinics, and therefore willing to provide semen samples, but the participation bias of such recruitment hinders extrapolation to the unselected general male population.

METHODS

We have taken the opportunity to study a convenience sample of 55 healthy, non-infertile men ranging in age from 52 to 79 years old who provided semen samples as part of a prostate cancer screening project. They were compared with a control group (n = 409) of younger (< 52 years) men from among 567 volunteers screened as potential sperm donors for an artificial insemination program.

RESULTS

Older men had lower semen volume (mean semen volume 1.8 versus 3.2 ml; P < 0.0001) and total sperm output (median 74 versus 206 million sperm per ejaculate; P < 0.0001), whereas sperm density (median 64 versus 73 million sperm/ml; P = 0.12) was non-significantly decreased. Older men had more abnormal sperm morphology with decreasing numbers of normal forms (mean 14% versus 25%; P < 0.0001) and reduced vitality (mean 51% versus 80%; P < 0.0001), as well as increased numbers of cytoplasmic droplets (median 1 versus 0; P < 0.0001) and sperm tail abnormalities (30% versus 17%; P < 0.0001). Sperm head or neck abnormalities were no different between the groups.

CONCLUSIONS

While neither study group may be representative of the general male population, these findings suggest that sperm production, reflected in sperm output but not sperm density, as well as sperm morphology and viability are diminished in this population of healthy, non-infertile older men.

Role of CT-guided core needle biopsy in the diagnosis of a gossypiboma: case report

A 66-year-old woman with previous hysterectomy had dysuria and vaginal spotting for 1 month. Computed tomography showed a heterogeneous presacral mass with eccentric calcification. Biopsies of the bladder and vagina and transrectal biopsy of the pelvic mass yielded only inflammation. T2-weighted magnetic resonance images revealed a heterogeneous mass with wavy hypointensities. Computed tomographically guided biopsy targeting at the calcified area disclosed thread-like materials, thus confirming the diagnosis of gossypiboma.

Extracorporeal shockwave lithotripsy and intracorporeal lithotripsy for proximal ureteric calculi--a comparative assessment of efficacy and safety

INTRODUCTION

Extracorporeal shockwave lithotripsy (ESWL) is the treatment modality of choice of many urologists for proximal ureteric calculi. In this study, we compared the efficacy and safety of ESWL versus ureteroscopy with holmium laser lithotripsy for the treatment of this group of stones.

MATERIALS AND METHODS

Between May 1999 and October 2000, 50 patients had ESWL and another 51 patients underwent ureteroscopy with holmium laser lithotripsy for proximal ureteric calculi. The two groups were similar in age, sex ratio and stone size. ESWL was performed with the Dornier Compact lithotriptor whereas holmium laser lithotripsy was performed via retrograde ureteric access with a Wolf 7.5 Fr semirigid ureteroscope.

RESULTS

Ureteroscopy with holmium laser lithotripsy was significantly better in terms of the mean procedure time (56 min in ESWL; 25 min in ureteroscopy; P < 0.001) and the 1-month stone free rate (50% in ESWL; 80% in ureteroscopy; P = 0.001). The 3-month stone free rate was also higher for ureteroscopy (78% in ESWL; 90% in ureteroscopy) but this difference was not statistically significant (P = 0.09). Minor complications of steinstrasse (6%) occurred in ESWL and proximal stone migration (8%) occurred during ureteroscopy.

CONCLUSION

Ureteroscopy with holmium laser lithotripsy is a viable and safe alternative to ESWL for the management of proximal ureteric calculi.

Magnetic resonance imaging of hyaline cartilage regeneration in neocartilage graft implantation

BACKGROUND

The purpose of this study was to investigate the regenerative potential of hyaline cartilage in a neocartilage graft implant with the aid of MR cartilage imaging using a rabbit model.

METHODS

Surgical osteochondral defects were created in the femoral condyles of 30 mature New Zealand rabbits. The findings of neocartilage in autologous cartilage grafts packed into osteochondral defects were compared with control group of no implant to the osteochondral defect. The outcome of the implantations was correlated with histologic and MR cartilage imaging findings over a 3-month interval.

RESULTS

Neocartilage grafts packed into osteochondral defects showed regeneration of hyaline cartilage at the outer layer of the implant using MR cartilage imaging. Fibrosis of fibrocartilage developed at the outer layer of the autologous cartilage graft together with an inflammatory reaction within the osteochondral defect.

CONCLUSION

This animal study provides evidence of the regenerative ability of hyaline cartilage in neocartilage transplants to repair articular cartilage.

Radiofrequency ablation as a salvage procedure for ruptured hepatocellular carcinoma

Spontaneous rupture of hepatocellular carcinoma is a distinct presentation causing acute abdomen. Different treatment approaches have been advocated including emergency hepatectomy, initial hemostasis by hepatic artery ligation or transarterial embolization and second-stage hepatectomy. Unrecognized ruptured hepatocellular carcinoma during laparotomy is often encountered in countries where the incidence of hepatocellular carcinoma is low. Radiofrequency ablation is a new localized thermal ablative technique for the treatment of unresectable hepatic tumors including hepatocellular carcinoma. We report a case where radiofrequency ablation was used as a salvage procedure for ruptured hepatocellular carcinoma during emergency laparotomy.