Sustained oxidation of Tea-Fe(III)/H2O2 simultaneously achieves sludge reduction and carbamazepine removal: The crucial role of EPS regulation

Establishing an economic and sustained Fenton oxidation system to enhance sludge dewaterability and carbamazepine (CBZ) removal rate is a crucial path to simultaneously achieve sludge reduction and harmless. Leveraging the principles akin to "tea making", we harnessed tea waste to continually release tea polyphenols (TP), thus effectively maintaining high level of oxidation efficiency through the sustained Fenton reaction. The results illustrated that the incorporation of tea waste yielded more favorable outcomes in terms of water content reduction and CBZ removal compared to direct TP addition within the Fe(III)/hydrogen peroxide (H2O2) system. Concomitantly, this process mainly generated hydroxyl radical (•OH) via three oxidation pathways, effectively altering the properties of extracellular polymeric substances (EPS) and promoting the degradation of CBZ from the sludge mixture. The interval addition of Fe(III) and H2O2 heightened extracellular oxidation efficacy, promoting the desorption and removal of CBZ. The degradation of EPS prompted the transformation of bound water to free water, while the formation of larger channels drove the discharge of water. This work achieved the concept of treating waste with waste through using tea waste to treat sludge, meanwhile, can provide ideas for subsequent sludge harmless disposal.

Investigation of Brain Iron in Niemann-Pick Type C: A 7T Quantitative Susceptibility Mapping Study

BACKGROUND AND PURPOSE

While brain iron dysregulation has been observed in several neurodegenerative disorders, its association with the progressive neurodegeneration in Niemann-Pick type C is unknown. Systemic iron abnormalities have been reported in patients with Niemann-Pick type C and in animal models of Niemann-Pick type C. In this study, we examined brain iron using quantitative susceptibility mapping MR imaging in individuals with Niemann-Pick type C compared with healthy controls.

MATERIALS AND METHODS

A cohort of 10 patients with adolescent- and adult-onset Niemann-Pick type C and 14 age- and sex-matched healthy controls underwent 7T brain MR imaging with T1 and quantitative susceptibility mapping acquisitions. A probing whole-brain voxelwise comparison of quantitative susceptibility mapping between groups was conducted. Mean quantitative susceptibility mapping in the ROIs (thalamus, hippocampus, putamen, caudate nucleus, and globus pallidus) was further compared. The correlations between regional volume, quantitative susceptibility mapping values, and clinical features, which included disease severity on the Iturriaga scale, cognitive function, and the Social and Occupational Functioning Assessment Scale, were explored as secondary analyses.

RESULTS

We observed lower volume in the thalamus and voxel clusters of higher quantitative susceptibility mapping in the pulvinar nuclei bilaterally in patients with Niemann-Pick type C compared with the control group. In patients with Niemann-Pick type C, higher quantitative susceptibility mapping in the pulvinar nucleus clusters correlated with lower volume of the thalamus on both sides. Moreover, higher quantitative susceptibility mapping in the right pulvinar cluster was associated with greater disease severity.

CONCLUSIONS

Our findings suggest iron deposition in the pulvinar nucleus in Niemann-Pick type C disease, which is associated with thalamic atrophy and disease severity. This preliminary evidence supports the link between iron and neurodegeneration in Niemann-Pick type C, in line with existing literature on other neurodegenerative disorders.

Ions play different roles in virus removal caused by different NOMs in UF process: Removal efficiency and mechanism analysis

In this study, we investigated the effect of different compositions of aquatic natural organic matter (NOM) and ions on virus removal by ultrafiltration (UF). MS2 bacteriophage was used as a surrogate. Humic acid (HA) improved the MS2 removal rate from 1.95 ± 0.09 LRV to 2.40 ± 0.03 LRV at the HA dosage of 9 mg/L through the combined mechanisms of size exclusion, electrostatic repulsion and hydrophobicity. MS2 removal rate further increased to 3.10 ± 0.05 LRV by 10 mmol/L Na⁺ dosage and 3.19 ± 0.12 LRV by Ca²⁺ 1 mmol/L in the HA-containing UF system. Size exclusion turned into the dominant virus removal mechanism according to the results of the fouling model fitting and the weakening of electrostatic repulsion and hydrophobicity. The complexation of Ca²⁺ also played a role in MS2 removal based on the analysis of interaction force. MS2 removal rate by bovine serum albumin (BSA) was poor, which was 2.07 ± 0.06 LRV at the BSA dosage of 9 mg/L. Hydrophobicity was greatly reduced and the dominant virus removal mechanisms were size exclusion and electrostatic repulsion. 10 mmol/L Na⁺ in the presence of BSA deteriorated MS2 removal rate to 2.02 ± 0.07 LRV by the weakening of electrostatic repulsion, hydrophobicity and size exclusion. Electrostatic repulsion severely decreased by 1 mmol/L Ca²⁺ and the enhanced adsorption barrier represented competitive adsorption of Ca²⁺ by BSA and MS2 contributed for MS2 removal further decline (1.99 ± 0.05 LRV). Complex components in water will have different effects on virus removal due to their properties and interactions. This study can provide references for selecting more efficient water treatment methods according to the different compositions of raw water in actual water treatment applications during the UF process. Moreover, the retention of virus by UF can be predicted based on our study results.

Care navigation increases initiation of hepatitis C treatment following release from prison in a prospective randomised controlled trial: The C-LINK Study

Background

Prison-based hepatitis C treatment is safe and effective; however, many individuals are released untreated due to time or resource constraints. On community re-entry, individuals face a number of immediate competing priorities, and in this context, linkage to hepatitis C care is low. Interventions targeted at improving healthcare continuity after prison release have yielded positive outcomes for other health diagnoses; however, data regarding hepatitis C transitional care are limited.

Methods

We conducted a prospective randomized controlled trial comparing a hepatitis C care navigator intervention with standard of care for individuals released from prison with untreated hepatitis C infection. The primary outcome was prescription of hepatitis C direct-acting antivirals (DAA) within 6 months of release.

Results

Forty-six participants were randomized. The median age was 36 years and 59% were male. Ninety percent (n = 36 of 40) had injected drugs within 6 months before incarceration. Twenty-two were randomized to care navigation and 24 were randomized to standard of care. Individuals randomized to the intervention were more likely to commence hepatitis C DAAs within 6 months of release (73%, n = 16 of 22 vs 33% n = 8 of 24, P < .01), and the median time between re-entry and DAA prescription was significantly shorter (21 days [interquartile range {IQR}, 11–42] vs 82 days [IQR, 44–99], P = .049).

Conclusions

Care navigation increased hepatitis C treatment uptake among untreated individuals released from prison. Public policy should support similar models of care to promote treatment in this high-risk population. Such an approach will help achieve hepatitis C elimination as a public health threat.

Controlling the hydraulic resistance of membrane biofilms by engineering biofilm physical structure

The application of membrane technology for water treatment and reuse is hampered by the development of a microbial biofilm. Biofilm growth in micro-and ultrafiltration (MF/UF) membrane modules, on both the membrane surface and feed spacer, can form a secondary membrane and exert resistance to permeation and crossflow, increasing energy demand and decreasing permeate quantity and quality. In recent years, exhaustive efforts were made to understand the chemical, structural and hydraulic characteristics of membrane biofilms. In this review, we critically assess which specific structural features of membrane biofilms exert resistance to forced water passage in MF/UF membranes systems applied to water and wastewater treatment, and how biofilm physical structure can be engineered by process operation to impose less hydraulic resistance ("below-the-pain threshold"). Counter-intuitively, biofilms with greater thickness do not always cause a higher hydraulic resistance than thinner biofilms. Dense biofilms, however, had consistently higher hydraulic resistances compared to less dense biofilms. The mechanism by which density exerts hydraulic resistance is reported in the literature to be dependant on the biofilms' internal packing structure and EPS chemical composition (e.g., porosity, polymer concentration). Current reports of internal porosity in membrane biofilms are not supported by adequate experimental evidence or by a reliable methodology, limiting a unified understanding of biofilm internal structure. Identifying the dependency of hydraulic resistance on biofilm density invites efforts to control the hydraulic resistance of membrane biofilms by engineering internal biofilm structure. Regulation of biofilm internal structure is possible by alteration of key determinants such as feed water nutrient composition/concentration, hydraulic shear stress and resistance and can engineer biofilm structural development to decrease density and therein hydraulic resistance. Future efforts should seek to determine the extent to which the concept of "biofilm engineering" can be extended to other biofilm parameters such as mechanical stability and the implication for biofilm control/removal in engineered water systems (e.g., pipelines and/or, cooling towers) susceptible to biofouling.

Biofouling control by phosphorus limitation strongly depends on the assimilable organic carbon concentration

Nutrient limitation is a biofouling control strategy in reverse osmosis (RO) membrane systems. In seawater, the assimilable organic carbon content available for bacterial growth ranges from about 50 to 400 μg C·L^-1, while the phosphorus concentration ranges from 3 to 11 μg P·L^-1. Several studies monitored biofouling development, limiting either carbon or phosphorus. The effect of carbon to phosphorus ratio and the restriction of both nutrients on membrane system performance have not yet been investigated. This study examines the impact of reduced phosphorus concentration (from 25 μg P·L^-1 and 3 μg P·L^-1, to a low concentration of ≤0.3 μg P·L^-1), combined with two different carbon concentrations (250 C L^-1 and 30 μg C·L^-1), on biofilm development in an RO system. Feed channel pressure drop was measured to determine the effect of the developed biofilm on system performance. The morphology of the accumulated biomass for both carbon concentrations was characterized by optical coherence tomography (OCT) and the biomass amount and composition was quantified by measuring total organic carbon (TOC), adenosine triphosphate (ATP), total cell counts (TCC), and extracellular polymeric substances (EPS) concentration for the developed biofilms under phosphorus restricted (P-restricted) and dosed (P-dosed) conditions. For both carbon concentrations, P-restricted conditions (≤0.3 μg P·L^-1) limited bacterial growth (lower values of ATP, TCC). A faster pressure drop increase was observed for P-restricted conditions compared to P-dosed conditions when 250 μg C·L^-1 was dosed. This faster pressure drop increase can be explained by a higher area covered by biofilm in the flow channel and a higher amount of produced EPS. Conversely, a slower pressure drop increase was observed for P-restricted conditions compared to P-dosed conditions when 30 μg C·L^-1 was dosed. Results of this study demonstrate that P-limitation delayed biofilm formation effectively when combined with low assimilable organic carbon concentration and thereby, lengthening the overall membrane system performance.

Association between Cognitive Function and Clustered Cardiovascular Risk of Metabolic Syndrome in Older Adults at Risk of Cognitive Decline

OBJECTIVES

Metabolic syndrome (MetS) represents a cluster of obesity and insulin resistance-related comorbidities. Abdominal obesity, hypertension, elevated triglyceride and glucose levels are components of MetS and may have a negative effect on cognitive function, but few cognitive studies have examined the combined risk severity. We sought to determine which specific cognitive abilities were associated with MetS in older adults at risk of cognitive decline.

DESIGN

Cross-sectional study.

PARTICIPANTS

108 AIBL Active participants with memory complaints and at least one cardiovascular risk factor.

MEASUREMENTS

Cardiovascular parameters and blood tests were obtained to assess metabolic syndrome criteria. The factors of MetS were standardized to obtain continuous z-scores. A battery of neuropsychological tests was used to evaluate cognitive function.

RESULTS

Higher MetS z-scores were associated with poorer global cognition using ADAS-cog (adjusted standardized beta=0.26, SE 0.11, p<0.05) and higher Trail Making B scores (adjusted beta=0.23, SE 0.11, p<0.05). Higher MetS risk was related to lower cognitive performance.

CONCLUSION

Combined risk due to multiple risk factors in MetS was related to lower global cognitive performance and executive function. A higher MetS risk burden may point to opportunities for cognitive testing in older adults as individuals may experience cognitive changes.

Biofilm compressibility in ultrafiltration: A relation between biofilm morphology, mechanics and hydraulic resistance

Poroelastic fluid-structure interaction models were coupled to experimental data to determine the effects of biofilm spatial distribution of mechanical and hydraulic properties on the biofilm hydraulic resistance and compressibility in membrane filtration processes. Biofilms were cultivated on ultrafiltration membranes for 20 and 30 days under high (0.28 bar) and low (0.06 bar) transmembrane pressure (TMP), in dead-end filtration mode. Subsequently, biofilms were subjected to a compression/relaxation cycles by step-wise TMP changes. Structural deformation of biofilms during compression was observed in-situ using optical coherence tomography. Experimental results show that the observed increase in the biofilm hydraulic resistance during compression is not necessarily accompanied by a detectable biofilm thickness reduction. A dual-layer biofilm model with a dense base and porous top layer could explain these observed results. Because porosity controls indirectly the mechanical response of biofilms under compression, results could be described without assuming a gradient in mechanical properties within the biofilm. The biofilm surface roughness did not significantly influence the water flux in this study. However, the fraction of biofilm base layer directly exposed to bulk liquid could be a good indicator in the determination of water flux. The main implications of this study for the design and operation of low-pressure membrane systems (e.g., MF and UF with fouling layer being the main filtration resistance) lays in the selection of favorable operational TMP and biofilm morphology.

Source Community and Assembly Processes Affect the Efficiency of Microbial Microcystin Degradation on Drinking Water Filtration Membranes

Microbial biofilms in gravity-driven membrane (GDM) filtration systems can efficiently degrade the cyanotoxin microcystin (MC), but it is unclear if this function depends on the presence of MC-producing cyanobacteria in the source water habitat. We assessed the removal of MC from added Microcystis aeruginosa biomass in GDMs fed with water from a lake with regular blooms of toxic cyanobacteria (ExpL) or from a stream without such background (ExpS). While initial MC removal was exclusively due to abiotic processes, significantly higher biological MC removal was observed in ExpL. By contrast, there was no difference in MC degradation capacity between lake and stream bacteria in separately conducted liquid enrichments on pure MC. Co-occurrence network analysis revealed a pronounced modularity of the biofilm communities, with a clear hierarchic distinction according to feed water origin and treatment type. Genotypes in the network modules associated with ExpS had significantly more links to each other, indicating that these biofilms had assembled from a more coherent source community. In turn, signals for stochastic community assembly were stronger in ExpL biofilms. We propose that the less "tightly knit" ExpL biofilm assemblages allowed for the better establishment of facultatively MC degrading bacteria, and thus for higher overall functional efficiency.

Gravity-driven membrane filtration for water and wastewater treatment: A review

Gravity-driven membrane (GDM) filtration has been investigated for almost 10 years. The technology is characterized not only by relatively lower transmembrane pressures which can be achieved by gravity (extremely low energy consumption), but also by the phenomenon of flux stabilization: A biofilm is allowed to form on the membrane and a stabilization of flux occurs which is related to biological processes within the biofilm layer on the membrane. This enables stable operation during a year or longer without any cleaning or flushing. Initially, the technology was developed mainly for household drinking water treatment, but in the meantime, the research and application has expanded to the treatment of greywater, rainwater, and wastewater as well as the pretreatment of seawater for desalination. This review covers the field from the rather fundamental research on biofilm morphology and microbial community analysis to the impact of feedwater composition, process parameters and organic removal performance. Not only household applications, but also for community-scale treatment and full-scale applications are discussed. In addition, the application potential is highlighted in comparison to conventional ultrafiltration. Finally, an overall assessment is illustrated and the research and development needs are identified.

Effect of biofilm structural deformation on hydraulic resistance during ultrafiltration: A numerical and experimental study

Biofilm formation in membrane systems negatively impacts the filtration system performances. This study evaluated how biofilm compression driven by permeate flow increases the hydraulic resistance and leads to reduction in permeate flux. We analysed the effect of biofilm compression on hydraulic resistance and permeate flux through computational models supported by experimental data. Biofilms with homogeneous surface structure were subjected to step-wise changes in flux and transmembrane pressure during compression and relaxation tests. Biofilm thickness under applied forces was measured non-invasively in-situ using optical coherence tomography (OCT). A numerical model of poroelasticity, which couples water flow through the biofilm with biofilm mechanics, was developed to correlate the structural deformation with biofilm hydraulics (permeability and resistance). The computational model enabled extracting mechanical and hydrological parameters corresponding to the experimental data. Homogeneous biofilms under elevated compression forces experienced a significant reduction in thickness while only a slight increase in resistance was observed. This shows that hydraulic resistance of homogeneous biofilms was affected more by permeability decrease due to pore closure than by a decrease in thickness. Both viscoelastic and elastoplastic models could describe well the permanent biofilm deformation. However, for biofilms under study, a simpler elastic model could also be used due to the small irreversible deformations. The elastic moduli fitting the measured data were in agreement with other reported values for biofilm under compression. Biofilm stiffening under larger flow-driven compression forces was observed and described numerically by correlating inversely the elastic modulus with biofilm porosity. The importance of this newly developed method lies in estimation of accurate biofilm mechanical parameters to be used in numerical models for both membrane filtration system and biofouling cleaning strategies. Such model can ultimately be used to identify optimal operating conditions for membrane system subjected to biofouling.

Physical structure determines compression of membrane biofilms during Gravity Driven Membrane (GDM) ultrafiltration

Increasing transmembrane pressure (TMP) can compress and increase the hydraulic resistance of membrane biofilms. The purpose of the present study is to evaluate how compression of membrane biofilms occurs and how structural rearrangement can affect hydraulic resistance. Biofilms with heterogeneous and homogeneous physical structures were grown in membrane fouling simulators (MFS) in dead-end mode for 20 days with either (i) a nutrient enriched condition with a nutrient ratio of 100:30:10 (C: N: P), (ii) a phosphorus limitation (C: N: P ratio: 100:30:0), or (iii) river water (C: N: P ratio: ca. 100:10:1). The structural and hydraulic response of membrane biofilms to (a) changes in transmembrane pressures (0.06-0.1-0.5-0.1-0.06 bar) and (b) changes in permeate flux (10-15-20-15-10 L/m²/h) were investigated. Optical coherence tomography (OCT) was used to monitor biofilm structural response, and OCT images were processed to quantify changes in the mean biofilm thickness and relative roughness. Nutrient enriched and river water biofilms had heterogeneous physical structures with greater surface roughness (Ra' > 0.2) than homogeneous P limiting biofilms (Ra' < 0.2). Compression of biofilms with rough heterogeneous structures (Ra' > 0.2) was irreversible, indicated by irreversible decrease in surface roughness, partial relaxation in mean biofilm thickness and irreversible increase in hydraulic resistance. Compression of homogeneous biofilm (Ra' < 0.2) was on the other hand reversible, indicated by full relaxation of the biofilms structure and restoration of initial hydraulic resistance. Hydraulic response (i.e., change in the specific biofilm resistance) did not correspond with the change in physical structure of heterogeneous biofilms. The presented study provides a fundamental understanding of how biofilm physical structure can affect the biofilm's response to a change in TMP, with practical relevance for the operation of GDM filtration systems.

Linking composition of extracellular polymeric substances (EPS) to the physical structure and hydraulic resistance of membrane biofilms

The effect of extracellular polymeric substances (EPS) on the meso-scale physical structure and hydraulic resistance of membrane biofilms during gravity driven membrane (GDM) filtration was investigated. Biofilms were developed on the surface of ultrafiltration membranes during dead-end filtration at ultra-low pressure (70 mbar). Biofilm EPS composition (total protein, polysaccharide and eDNA) was manipulated by growing biofilms under contrasting nutrient conditions. Nutrient conditions consisted of (i) a nutrient enriched condition with a nutrient ratio of 100:30:10 (C: N: P), (ii) a phosphorus limitation (C: N: P ratio: 100:30:0), and (iii) a nitrogen limitation (C: N: P ratio: 100:0:10). The structure of the biofilm was characterised at meso-scale using Optical Coherence Tomography (OCT). Biofilm composition was analysed with respect to total organic carbon, total cellular mass and extracellular concentrations of proteins, polysaccharides, and eDNA. 2D-confocal Raman mapping was used to characterise the functional group composition and micro-scale distribution of the biofilms EPS. Our study reveals that the composition of the EPS matrix can determine the meso-scale physical structure of membrane biofilms and in turn its hydraulic resistance. Biofilms grown under P limiting conditions were characterised by dense and homogeneous physical structures with high concentrations of polysaccharides and eDNA. Biofilm grown under nutrient enriched or N limiting conditions were characterised by heterogeneous physical structures with lower concentrations of polysaccharides and eDNA. For P limiting biofilms, 2D-confocal Raman microscopy revealed a homogeneous spatial distribution of anionic functional groups in homogeneous biofilm structures with higher polysaccharide and eDNA concentrations. This study links EPS composition, physical structure and hydraulic resistance of membrane biofilms, with practical relevance for the hydraulic performances of GDM ultrafiltration.

Influence of food and lifestyle on the risk of developing inflammatory bowel disease

BACKGROUND

The Barwon area in Australia has one of the highest incidence rates of inflammatory bowel disease (IBD) and therefore is an ideal location to study the impact of environmental exposures on the disease's development.

AIM

To study these exposures prior to the development of IBD in a population-based cohort.

METHOD

One hundred and thirty-two incident cases (81 Crohn disease (CD) and 51 ulcerative colitis (UC)) from an IBD registry and 104 controls replied to the International Organization of Inflammatory Bowel Diseases environmental questionnaire. This included 87 questions about pre-illness exposures that included childhood illnesses, vaccinations, breastfeeding, house amenities, pets and swimming, diet and smoking.

RESULTS

The factors associated with CD included smoking (odds ratio (OR): 1.42, confidence interval (CI): 1-2.02, P = 0.029); childhood events, including tonsillectomy (OR: 1.74, CI: 1.15-2.6, P = 0.003) and chicken pox infection (OR: 3.89, CI: 1.61-9.4, P = 0.005) and pre-diagnosis intake of frequent fast food (OR: 2.26, CI: 1.76-4.33, P = 0.003). In UC, the risk factors included smoking (OR: 1.39, CI: 1.1-1.92, P = 0.026) and pre-diagnosis intake of frequent fast food (OR: 2.91, CI: 1.54-5.58, P < 0.001), and high caffeine intake was protective (OR: 0.51, 95% CI: 0.3-0.87, P = 0.002). Other protective exposures for UC included high fruit intake (OR: 0.59, CI: 0.4-0.88, P = 0.003) and having pets as a child (OR: 0.36, CI: 0.2-0.79, P = 0.001).

CONCLUSION

This first Australian population-based study of environmental risk factors confirms that smoking, childhood immunological events and dietary factors play a role in IBD development; while high caffeine intake and pet ownership offer a protective effect.

Subcortical volumetric reductions in adult Niemann-Pick disease type C: a cross-sectional study

BACKGROUND AND PURPOSE

Voxel-based analysis has suggested that deep gray matter rather than cortical regions is initially affected in adult Niemann-Pick type C. We sought to examine a range of deep gray matter structures in adults with NPC and relate these to clinical variables.

MATERIALS AND METHODS

Ten adult patients with NPC (18-49 years of age) were compared with 27 age- and sex-matched controls, and subcortical structures were automatically segmented from normalized T1-weighted MR images. Absolute volumes (in cubic millimeters) were generated for a range of deep gray matter structures and were compared between groups and correlated with illness variables.

RESULTS

Most structures were smaller in patients with NPC compared with controls. The thalamus, hippocampus, and striatum showed the greatest and most significant reductions, and left hippocampal volume correlated with symptom score and cognition. Vertex analysis of the thalamus, hippocampus, and caudate implicated regions involved in memory, executive function, and motor control.

CONCLUSIONS

Thalamic and hippocampal reductions may underpin the memory and executive deficits seen in adult NPC. Volume losses in other subcortical regions may also be involved in the characteristic range of motor, psychiatric, and cognitive deficits seen in the disease.

Preoperative magnetic resonance spectroscopy improves diagnostic accuracy in a series of neurosurgical dilemmas

OBJECT

The purpose of this study was to evaluate the usefulness of preoperative magnetic resonance spectroscopy (MRS) in neurosurgical patients with diagnostically challenging intracranial lesions.

METHODS

Included in this study are twenty-three consecutive patients presenting to the neurosurgery service with diagnostically challenging intracranial lesions and who were investigated by conventional MR imaging and proton ((1)H) MRS, followed by surgery with subsequent histopathological diagnosis. An experienced neuroradiologist (RJ) blinded to the final histopathology evaluated the imaging studies retrospectively. Provisional diagnoses based on preoperative clinical and conventional MR data versus preoperative MRS data were compared with definitive histopathological diagnoses.

RESULTS

Compared with preoperative clinical and conventional MR data, (1)H MRS improved the accuracy of MR imaging from 60.9% to 83%. We found (1)H MRS reliably distinguished between abscess and high-grade tumour, and between high-grade glioma and low-grade glioma, but was not able to reliably distinguish between recurrent glioma and radiation necrosis. In 12/23 cases (52%) the (1)H MRS findings positively altered our clinical management. Two representative cases are presented.

CONCLUSIONS

Our study supports a beneficial role for (1)H MRS in certain diagnostic intracranial dilemmas presenting to neurosurgeons. The information gleaned from preoperative (1)H MRS can be a useful adjunct to clinical and conventional MR imaging data in guiding the management of patients with intracranial pathologies, particularly high-grade tumour versus abscess, and high-grade versus low-grade glioma. Further larger prospective studies are needed to clearly define the utility of (1)H MRS in diagnostically challenging intracranial lesions in neurosurgery.

Rapidly progressive Whipple's disease of the central nervous system

We describe a patient with rapidly progressive Whipple's disease confined to the central nervous system (CNS). The diagnosis was made pre-mortem following stereotactic and open brain biopsis and confirmed at autopsy. Despite appropriate antibiotic treatment, the disease ran a fulminant course to death after nine weeks.

Pontine-to-midbrain ratio indexes ocular-motor function and illness stage in adult Niemann-Pick disease type C

BACKGROUND AND PURPOSE

Niemann-Pick disease type C (NPC) is a progressive neurovisceral disorder associated with dystonia, ataxia and a characteristic gaze palsy. Neuropathological studies have demonstrated brainstem atrophy associated with neuronal inclusions and loss, and neurofibrillary tangles, although it is not known whether this pathology can be detected in vivo or how these changes relate to illness variables, particularly ocular-motor changes. Our aim was to utilize a method for brainstem atrophy, validated in progressive supranuclear palsy (PSP), in a group of adult patients with NPC, and explore its relationship to illness variables and ocular-motor functioning.

METHODS

We calculated the midbrain and pontine area, and pontine-to-midbrain ratio (PMR) from midsagittal images of 10 adult patients with NPC and 27 age- and gender-matched controls. Measures were correlated with illness variables, and measures of horizontal saccadic functioning.

RESULTS

Pontine-to-midbrain ratio was 14% higher in the NPC group, but this difference was not significant. However, PMR showed a significant positive correlation with duration of illness and a measure of illness severity. Furthermore, PMR was significantly negatively correlated with saccadic peak velocity and gain, and self-paced saccadic performance.

CONCLUSIONS

Pontine-to-midbrain ratio was increased in adult patients with NPC compared to controls, although not to the same degree as previously described in PSP, which also presents with significant gaze palsy. These changes were driven predominantly by progressive midbrain atrophy. The strong correlation with illness and ocular-motor variables suggests that it may be a useful marker for illness progression in NPC.

White and gray matter alterations in adults with Niemann-Pick disease type C: a cross-sectional study

OBJECTIVE

Niemann-Pick disease type C (NPC) is a progressive neurovisceral disorder with disrupted intracellular cholesterol metabolism that results in significant alterations to neuronal and axonal structure. Adult patients present with ataxia, gaze palsy, impaired cognition, and neuropsychiatric illness, but the neural substrate has not been well-characterized in vivo. Our aim was to investigate a well-characterized sample of adults with confirmed NPC for gray and white matter abnormalities.

METHODS

We utilized a combination of optimized voxel-based morphometry of T1-weighted images and tract-based spatial statistics of diffusion tensor images to examine gray matter volume and white matter structural differences in 6 adult patients with NPC and 18 gender- and age-matched controls.

RESULTS

Patients with NPC demonstrated bilateral gray matter reductions in large clusters in bilateral hippocampus, thalamus, superior cerebellum, and insula, in addition to smaller regions of inferoposterior cortex. Patients demonstrated widespread reductions in fractional anisotropy in major white matter tracts. Subsequent analysis of measures of axial and radial diffusivity suggest that these changes are contributed to by both impaired myelination and altered axonal structure.

CONCLUSIONS

Findings in gray matter areas are broadly consistent with human and animal studies of selective vulnerability of neuronal populations to the neuropathology of NPC, whereas more widespread white matter changes are consistent with the hypothesis that disrupted myelination and axonal structure predate changes to the neuronal cell body. These findings suggest that volumetric analysis of gray matter and diffusion tensor imaging may be useful modalities for indexing illness stage and monitoring response to emerging treatment.

Characterization of the innate immune signalling pathways in hepatocyte cell lines

Hepatitis B virus (HBV) infection is a major cause of liver-related morbidity and mortality. Toll-like receptors (TLRs) have recently been recognized to play an important role in the pathogenesis of chronic hepatitis B (CH-B). Furthermore, manipulation of TLR signalling pathways shows potential as an antiviral therapeutic strategy. Whether hepatocytes themselves possess intact TLR signalling pathways remains controversial. It is critical that cell culture models be developed to allow investigation of the interaction between HBV and the TLR signalling pathways. We have screened three hepatocyte cell lines for the integrity of pro-inflammatory responses and antiviral cytokines following stimulation with interleukin-1 (IL-1) and different TLR ligands. We observed that Huh-7, HepG2 and PH5CH8 cells selectively responded to IL-1 and TLR2 ligands, leading to the activation of NF-kappaB. In addition, the PH5CH8 cell lines were able to induce type 1 interferon (IFN) via both TLR3 and RIG-I following stimulation with poly I:C, HepG2 cells mounted an IFN response via RIG-I only, whereas Huh-7 cells were unresponsive. We conclude that the hepatocyte cell lines investigated display a repertoire of TLR signalling, albeit limited, suggesting that hepatocytes may themselves play an active role in innate immune responses to viruses such as HBV. Furthermore, particular hepatoma cell lines are suitable for investigating the interaction between HBV and hepatocyte-expressed pattern recognition receptors.

Contrast-enhanced perfusion and diffusion MRI accurately lateralize temporal lobe epilepsy: a pilot study

AIMS

To undertake a pilot study to assess whether magnetic resonance (MR) contrast-enhanced perfusion imaging (CEPI) and diffusion-weighted imaging (DWI) provide lateralizing information in medically refractory temporal lobe epilepsy (TLE),and to compare this to standard quantitative hippocampal assessments (volumetric measurements and T2 relaxometry).

METHODS

Ten patients with 'non-lesional' TLE and 10 control subjects were studied. Quantification of the relative cerebral blood flow (rCBF) and apparent diffusion coefficient (ADC) was performed for the hippocampal regions. The ratios of the ipsilateral-to-contralateral side (to the EEG lateralization) were compared with the side-to-side ratios in the controls.

RESULTS

Six patients (60%) had an ADC ratio outside the control range (the larger ADC ipsilateral to the EEG lateralization in all cases). The CBF ratios were outside the control range in all eight patients (100%) in whom CEPI was performed (the lower value ipsilateral to the EEG lateralization in all cases). The magnitude of the hippocampal volume (HV) ratios showed no significant correlation with the magnitude of the ADC ratios (R=-0.03, p=0.93) or CBF ratios (R=0.36, p=0.39). There was a closer relationship with the T2 relaxometry ratios, but this was also not significant (R=-0.40, p=0.32; R=0.58, p=0.08).

CONCLUSIONS

DWI and CEPI show potential as reliable tools for the lateralization of non-lesional TLE. Further studies with larger numbers are necessary to determine whether these techniques provide independent data to established MR quantitative measures.

The accuracy of EUS-FNA in assessing mediastinal lymphadenopathy and staging patients with NSCLC

Optimal management of nonsmall cell lung cancer (NSCLC) depends on tissue diagnosis and accurate staging. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is minimally invasive and provides cytological confirmation of malignant mediastinal disease. The aim was to assess the accuracy of EUS-FNA in cases of enlarged mediastinal lymphadenopathy (LN) of unknown aetiology and in the staging of NSCLC. A total of 52 consecutive patients with stage I-IIIb NSCLC or enlarged mediastinal LN of unknown aetiology underwent EUS-FNA. Negative results were confirmed with a surgical procedure: mediastinoscopy, video-assisted thoracic surgery (VATS) or lobectomy with systematic mediastinal lymph node dissection. In total, 34 patients had EUS-FNA performed for diagnosis, whilst the remaining 18 had EUS-FNA for staging. The overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy (95% confidence interval) were 93% (77-99), 100% (78-100), 100% (87-100), 88% (63-99) and 95% (84-99), respectively. When EUS-FNA was used in patients with NSCLC, the sensitivity, specificity, PPV, NPV and accuracy were 92% (73-99), 100% (69-100), 100% (85-100), 83% (51-98) and 94% (80-99), respectively. For mediastinal LN of unknown aetiology, no malignant disease was missed. Endoscopic ultrasound-guided fine-needle aspiration is an accurate tool for assessing mediastinal lymph node involvement in nonsmall cell lung cancer and in the diagnosis of unexplained mediastinal lymphadenopathy. Endoscopic ultrasound-guided fine-needle aspiration is a minimally invasive procedure that can be used as an adjunct or alternative to mediastinoscopy.

Perfusion thresholds in acute stroke thrombolysis

BACKGROUND AND PURPOSE

Perfusion-weighted MRI has been shown to be useful in the early identification of cerebral tissue at risk of infarction during acute ischemia. Identification of threshold perfusion measures that predict infarction may assist in the selection of patients for thrombolysis.

METHODS

Mean transit time (MTT), regional cerebral blood flow (rCBF), and regional cerebral blood volume (rCBV) maps were generated in 35 acute stroke patients (17 treated with tissue plasminogen activator and 18 control patients) imaged within 6 hours from symptom onset. Day 90 outcome infarcts (T2-weighted MRI) were superimposed on acute MTT, rCBF, and rCBV maps. Perfusion-weighted MRI measures were then calculated for 2 regions: infarcted and salvaged tissue.

RESULTS

MTT was prolonged by 22% in infarcted regions relative to salvaged tissue (P<0.001). rCBF was 10% lower in infarcted tissue than in salvaged regions (P<0.01). rCBV did not differ significantly between infarcted and salvaged regions. When reperfusion occurred, tissue with more severely prolonged MTT was salvaged from infarction relative to patients with persistent hypoperfusion (P<0.05). In contrast, rCBF in salvaged regions did not differ between patients with and without reperfusion. In reperfused patients, an inverse correlation (R=0.93, P<0.001) was found between time of initial MRI scan and MTT delay in salvaged tissue.

CONCLUSIONS

Both increases in MTT and decreases in rCBF predict infarction. Differences in MTT also predict salvage in more severely hypoperfused tissue after reperfusion, suggesting that it is the most clinically useful quantitative perfusion measure. Perfusion thresholds for infarction need to be assessed in the context of symptom duration.

Incidental radiological findings on brain magnetic resonance imaging in first-episode psychosis and chronic schizophrenia

OBJECTIVE

To investigate whether patients with first-episode psychosis or chronic schizophrenia have an increased incidence of magnetic resonance imaging (MRI) brain abnormalities compared with control subjects.

METHOD

Totally 340 clinical MRI reports [Controls (n=98), first-episode psychoses (n=152), chronic schizophrenia (n=90)] were reported by a neuroradiologist blind to diagnosis and subsequently categorized using referral criteria (immediate, urgent, routine or no referral).

RESULTS

Thirty percent of all scans were reported by a neuroradiologist as abnormal, but the majority required no referral. Patients with chronic schizophrenia were more likely to have clinically significant abnormal scans than patients with first episode psychosis or control subjects. In four patients the MRI findings led to the discovery of previously unsuspected pathology.

CONCLUSION

Patients with chronic schizophrenia have an increased prevalence of incidental brain abnormalities. A small proportion of patients with chronic schizophrenia and first-episode psychosis benefitted directly from MRI scanning.

Fas-mediated hepatocyte apoptosis is increased by hepatitis C virus infection and alcohol consumption, and may be associated with hepatic fibrosis: mechanisms of liver cell injury in chronic hepatitis C virus infection

Epidemiological studies have established that heavy alcohol consumption in persons with chronic hepatitis C virus (HCV) infection is associated with advanced liver disease, including cirrhosis. The aims of this study were to evaluate the relationship between alcohol consumption and hepatocyte apoptosis in HCV-infected patients and to determine the role of Fas in HCV-mediated apoptosis. Liver tissue from 44 HCV-infected patients with variable alcohol consumption, and 10 normal control subjects who did not consume alcohol was examined for hepatocyte apoptosis, proliferation and Fas expression. Alcohol consumption was assessed using the 'Lifetime Drinking History' alcohol questionnaire. HCV RNA, alanine aminotransferase (ALT) and ferritin were also assessed in addition to demographic data. Hepatocyte apoptosis was significantly greater in HCV-infected patients compared to controls. Expression of Fas (CD95) was found in HCV patients but not in controls. The degree of Fas expression correlated with hepatocyte apoptosis as detected by terminal UTP nick end labelling (TUNEL). Active ethanol consumption led to a significant increase in hepatocyte apoptosis. Fas expression correlated with fibrosis in HCV-infected patients who were not actively drinking ethanol. In summary, HCV leads to increased apoptotic cell death in hepatocytes. Programmed cell death can be further up-regulated by active ethanol consumption. The correlation between Fas expression and TUNEL supports the hypothesis that the Fas-Fas ligand interaction is the major mechanism for HCV-induced hepatocyte apoptosis.

A longitudinal study of hippocampal volume in first episode psychosis and chronic schizophrenia

Brain abnormalities have been identified in patients with schizophrenia, but what is unclear is whether these changes are progressive over the course of the disorder. In this longitudinal study, hippocampal and temporal lobe volumes were measured at two time points in 30 patients with first episode psychosis (mean follow-up interval=1.9 years, range 0.54-4.18 years) and 12 with chronic schizophrenia (mean follow-up interval=2.3 years, range 1.03-4.12 years) and compared to 26 comparison subjects (mean follow-up interval 2.2 years, range 0.86-4.18 years). Hippocampal, temporal lobe, whole-brain and intracranial volumes (ICV) were estimated from high-resolution magnetic resonance images. Only whole-brain volume showed significant loss over the follow-up interval in both patient groups. The rate of this volume loss was not different in the first episode group compared to the chronic group. There were no changes in either hippocampal or temporal lobe volumes. The negative findings for the hippocampus and temporal lobes may mean that the abnormalities in these regions are stable features of schizophrenia. Alternatively, the period before the onset of frank psychotic symptoms may be the point of greatest risk for progressive change.

Selective bilateral hippocampal volume loss in chronic schizophrenia

BACKGROUND

The hippocampus is implicated in the pathophysiology of schizophrenia; however, volumetric changes are subtle and have limited diagnostic specificity. It is possible that the shape of the hippocampus may be more characteristic of schizophrenia.

METHODS

Forty-five patients with chronic schizophrenia and 139 healthy control subjects were scanned using magnetic resonance imaging. Hippocampi were traced manually, and two-dimensional shape information was analyzed.

RESULTS

Two shape factors were found to be adequate to represent variance in the shape of the hippocampus. One of these factors, representing volume loss behind the head of the hippocampus, provided a degree of discrimination between patients with chronic schizophrenia and healthy control subjects; however, overall hippocampal volume following appropriate adjustment for brain volume showed a similar level of discrimination. Patients with chronic schizophrenia were best characterized using these two measures together, but diagnostic specificity was only moderate.

CONCLUSIONS

This study identified that less of the hippocampus was distributed in its posterior two-thirds in patients with chronic schizophrenia, and specifically in the region just posterior to the hippocampal head. Group discrimination on the basis of hippocampal volume and shape measures was moderately good. A full three-dimensional analysis of hippocampal shape, based on large samples, would be a useful extension of the study.

Combined magnetic resonance imaging and single-photon emission tomography scanning in the discrimination of Alzheimer's disease from age-matched controls

OBJECTIVE

To compare the utility of temporal lobe magnetic resonance imaging (MRI) and single-photon emission tomography (SPET) scanning in discriminating between subjects with Alzheimer's disease (AD) and age-matched controls.

METHODS

Thirty subjects with NINCDS-ADRDA AD (23 probable AD, 5 possible AD, 2 definite AD) and 22 age- and sex-matched controls underwent T1-weighted coronal MRI scanning (0.3 T) and technetium 99m-HMPAO SPET scanning. MRI scans were analyzed using a digitizer system with volumes of hippocampus, amygdala, entorhinal cortex, parahippocampal gyrus, and whole cerebral cortex calculated. From SPET scans, regional cerebral blood flow (rCBF) was assessed in anterior and posterior frontal, parietal, occipital, and mesial temporal cortex using a region of interest analysis with the cerebellum as a reference area.

RESULTS

Using MRI, the areas that best separated groups were left hippocampal and left amygdala volume, resulting in correct classification (patient vs. control) in 79% of cases (sensitivity 77%, specificity 82%). Exactly the same proportion of subjects were correctly classified by SPET, with the most discriminating rCBF changes being left parietal and right posterior frontal. Combining information from both scans improved the proportion of correctly classified subjects in a discriminant function to 90% (sensitivity 93%, specificity 86%; only 2 AD and 3 controls misclassified). All AD subjects had abnormalities on MRI and/or SPET (sensitivity for combined examinations 100%), while abnormalities on both MRI and SPET had a positive predictive value of 100% for dementia (including the detection of one control subject who later had dementia). Significant correlations between MRI and SPET measures were seen in control subjects but not in patients.

CONCLUSION

Both 0.3 T MRI and single rotating gamma camera SPET were equally useful in separating AD subjects from age-matched controls, although the combination of both significantly enhanced discrimination. In particular, all AD subjects had abnormalities on either MRI or SPET and both techniques may have an important role in assisting with clinical diagnosis, though replication in other centers and examination of differentiation of AD from other causes of dementia need to be examined.

Liver toxicity. Could this be a drug reaction?

BACKGROUND

Adverse reaction to prescription medications, over the counter medications and complementary medicines, are an important cause of liver toxicity.

OBJECTIVE

To highlight the importance of drug induced liver toxicity in patients presenting with abnormal liver function tests.

DISCUSSION

In patients who present with symptoms of liver dysfunction such as anorexia, itch or Jaundice and in whom liver function tests are abnormal, the possibility of an adverse reaction to medications should be considered. A detailed history of all medications taken in the past few months, including complementary medicines, should be obtained. After exclusion of other causes of liver disease such a viral hepatitis or gallstones, the cessation of the offending medication and the normalisation of liver tests is usually sufficient to establish a diagnosis. Occasionally, referral to a specialist and liver biopsy may be required.

A randomized, placebo-controlled study to evaluate the efficacy of 12-month famciclovir treatment in patients with chronic hepatitis B e antigen-positive hepatitis B

We conducted a randomized, placebo-controlled clinical study evaluating famciclovir (500 mg 3 times daily and 1.5 g once daily) for 1 year (6 months post-treatment follow-up) in patients with chronic hepatitis B e antigen (HBeAg)-positive hepatitis B virus (HBV) infection. The study was conducted in 80 centers in North America, Europe, and Australia/New Zealand. A total of 417 patients with histologically documented chronic hepatitis B (histologic activity index [HAI] 9.5-11.0) received famciclovir (500 mg 3 times daily or 1.5 g once daily) or placebo. Famciclovir 500 mg 3 times daily significantly reduced HBV DNA and median HAI scores versus placebo. By week 8, median HBV DNA decreased from 1,645 to 283 MEq/mL (famciclovir 500 mg 3 times daily) and from 1,147 to 304 MEq/mL (famciclovir 1.5 g once daily), while increasing for placebo (1,617 to 1,685 MEq/mL). Median change in HBV DNA at the end of therapy was -76% (famciclovir 500 mg 3 times daily; P <.01) and -60% (famciclovir 1.5 g once daily; P =.25) versus -37% for placebo. Median change in HAI was -1.5 points (famciclovir 500 mg 3 times daily; P =.02) and -1.0 point (famciclovir 1.5 g once daily; P =.35) and zero for placebo. Fifty percent of patients receiving famciclovir 500 mg 3 times daily (P =.07) and 43% receiving 1.5 g once daily (P =.41) experienced >/=2 points improvement in HAI versus 37% for placebo. Nine percent of patients treated with famciclovir 500 mg 3 times daily underwent anti-HBeAg seroconversion with undetectable HBV DNA at end of follow-up versus 3% in the placebo group (P =.05). Famciclovir was well tolerated; the incidence of post-treatment alanine transaminase (ALT) elevations was comparable with placebo. In conclusion, famciclovir 500 mg 3 times daily gave modest suppression of viral replication, but translated into significant histologic improvement in median HAI score at 1 year.

Where does treatment fit into the strategy to control hepatitis C?

The prevalence of hepatitis C varies greatly between countries of the Asia-Pacific region. The incidence of new cases is also markedly different between countries, particularly related to the prevalence of injecting drug use. Overall, the currently available treatments for hepatitis C are unlikely to have a major impact in the control of the infection from a population perspective while success rates are relatively low (20-45% sustained antiviral response) and treatment costs are high. There are some specific situations, such as reducing the incidence of mother-to-baby transmission or sexual transmission, where antiviral treatment can be used as a strategy to prevent further infection. The major aims of prevention of hepatitis C infection should lie with public health measures to prevent new infections, particularly amongst injecting drug users, and ultimately the development of an effective vaccine..

Magnetic resonance spectroscopy and schizophrenia: what have we learnt?

OBJECTIVE

Magnetic resonance spectroscopy (MRS) has been increasingly used to investigate the in vivo biochemistry of particular regions of the brain in patients with schizophrenia. We review the literature and discuss the theoretical constructs that form the presumed impetus for these studies in light of the current methodological limitations. Future directions are noted.

METHOD

The available published literature in English formed the basis for this review.

RESULTS

The results of 31P-MRS have been interpreted as reflecting a relative increase in cell membrane degradation in prefrontal cortical regions at certain phases of schizophrenia. 1H-MRS studies, though less consistent, provide evidence suggestive of a decrease in neuronal cell mass in the hippocampal region, which supports the findings of volumetric studies. Both groups of MRS studies support a neuro-developmental hypothesis of brain dysfunction in schizophrenia. However, current methodological problems limit the reliable interpretation of MRS data. A clear understanding of the methodology and its reliable interpretation is yet to emerge.

CONCLUSIONS

MRS remains a research instrument that is yet to be fully utilised in schizophrenia research. A few replicated findings are emerging, although the interpretation of these spectroscopic findings needs to be validated.

Echoplanar magnetic resonance imaging in acute stroke

Echoplanar magnetic resonance imaging (EPI) enables rapid, non-invasive imaging and analysis of cerebral pathophysiology in acute stroke. It represents an important clinical advance over computed tomography (CT) and conventional magnetic resonance (MR) scanning. It can rapidly delineate infarcted cerebral tissue and distinguish acute from chronic stroke. In addition, EPI has the potential to quickly determine the presence and degree of potentially viable brain tissue in the ischaemic penumbra. Thrombolysis is thought to reperfuse the penumbra and hence reduce infarct size. The thrombolytic agent tissue plasminogen activator (t-PA) improves outcome in ischaemic stroke when administered within the first 3 hours of onset. However, there is a significant risk of haemorrhage, and the time window for benefit may well exceed 3 hours in some patients. Hence, by facilitating diagnosis of 'at-risk' tissue in the ischaemic penumbra, a major clinical role of EPI may well become the rational selection of patients for acute interventional stroke therapy.

Addressing adverse events through clinical indicators

In an attempt to improve the reporting rate of adverse drug reactions the Adverse Drug Reaction Advisory Committee approached the Australian Council on Healthcare Standards Care Evaluation Program to develop a set of indicators to improve healthcare standards by heightening awareness amongst clinical staff of the morbidity, mortality and financial implications of adverse drug reactions. Ten clinical indicators addressing: (i) reporting of adverse drug reactions; (ii) adherence to treatment protocols for anaphylaxis; (iii) monitoring of warfarin; and (iv) monitoring of streptokinase, were field tested in ten Australian health-care organizations, to determine that the data were available, that the indicators were relevant to clinical practice and that the measures were achievable. Based on the results of this field test, six adverse drug reaction clinical indicators will be introduced into the Australian Council on Healthcare Standards Evaluation and Quality Improvement Program from January 1999.

Hippocampal volume in first-episode psychoses and chronic schizophrenia: a high-resolution magnetic resonance imaging study

BACKGROUND

It has been proposed that the hippocampus is a potential site for a neurodevelopmental lesion in schizophrenia. While smaller hippocampal volumes have been described in chronic schizophrenia, there have been few magnetic resonance imaging studies in first-episode psychosis. Furthermore, no studies have examined the specificity of this finding to first-episode schizophrenia, compared with first-episode affective psychosis.

METHODS

Hippocampal and whole-brain volumes were estimated using high-resolution magnetic resonance imaging in 140 controls, 46 patients with chronic schizophrenia, and 32 patients with first-episode psychosis.

RESULTS

Patients with chronic schizophrenia and first-episode psychosis had significantly smaller hippocampal volumes as compared with controls. Within the first-episode group, both patients with schizophrenia/schizophreniform psychosis and those with affective psychosis had smaller left hippocampal volumes as compared with controls. Smaller right hippocampal volumes were associated with age and illness duration in patients with chronic schizophrenia. Hippocampal volumes were not correlated with age of illness onset or medication dosage in either patient group.

CONCLUSIONS

These data show that smaller hippocampal volumes are present from the onset of illness. While these findings would support the neurodevelopmental model of schizophrenia, the finding of smaller left hippocampal volume in patients with first-episode schizophrenia and affective psychosis does not support the prediction that smaller hippocampi are specific to schizophrenia. The association of smaller right hippocampal volumes with increased illness duration in chronic schizophrenia suggests either that there is further neurodegeneration after illness onset or that bilateral small hippocampi predict chronicity.

Severe deep white matter lesions and outcome in elderly patients with major depressive disorder: follow up study

OBJECTIVE

To determine the difference in outcome among elderly people with major depression who do and do not have severe white matter lesions on magnetic resonance imaging.

DESIGN

Follow up study.

SETTING

Two psychiatric and two general hospitals in Melbourne, Australia.

SUBJECTS

60 depressed subjects aged over 55 referred to hospital psychiatric services with major depressive disorder meeting American Psychiatric Association (DSM-IIIR) criteria.

MAIN OUTCOME MEASURE

Proportion with good outcome as determined by full recovery from initial illness and no evidence of depressive relapse or cognitive decline during follow up among those with and without lesions.

RESULTS

Mean (SD) follow up was 31.9 (9.9) months. Survival analysis showed a significant effect of severe lesions on time to poor outcome (P=0.04), with median survival 136 days in those with severe lesions compared with 315 days in those without.

CONCLUSION

Severe white matter change on magnetic resonance imaging is associated with poor outcome in elderly depressed subjects.

Does hippocampal atrophy on MRI predict cognitive decline? A prospective follow-up study

OBJECTIVES

To investigate whether the presence of hippocampal atrophy (HCA) on MRI in Alzheimer's disease (AD) leads to a more rapid decline in cognitive function. To investigate whether cognitively unimpaired controls and depressed subjects with HCA are at higher risk than those without HCA of developing dementia.

DESIGN

A prospective follow-up of subjects from a previously reported MRI study.

SETTING

Melbourne, Australia.

PARTICIPANTS

Five controls with HCA and five age-matched controls without HCA, seven depressed subjects with HCA and seven without HCA, and 12 subjects with clinically diagnosed probable AD with HCA and 12 without HCA were studied. They were followed up at approximately 2 years with repeat cognitive testing, blind to initial diagnosis and MRI result.

MEASURES

HCA was rated by two radiologists blind to cognitive test score results. Cognitive assessment was by the Cambridge Cognitive Examination (CAMCOG).

RESULTS

No significant differences in rate of cognitive decline, mortality or progression to dementia were found between subjects with or without HCA.

CONCLUSIONS

HCA was not found to be a predictor of subsequent cognitive decline in this series.

Temporal lobe magnetic resonance imaging can differentiate Alzheimer's disease from normal ageing, depression, vascular dementia and other causes of cognitive impairment

BACKGROUND

Previous work suggests that temporal lobe magnetic resonance imaging (MRI) can distinguish those with dementia of the Alzheimer type (DAT) from healthy age-matched controls. However, its specificity with regard to conditions such as vascular dementia, depression and other disorders associated with cognitive impairment has not been determined.

METHODS

We studied 222 subjects using T1 weighted MRI with 5.1 mm coronal slices throughout the temporal lobe. Subjects included: healthy controls (N = 40); DSM-III-R major depression (N = 61); NINCDS/ADRDA DAT (N = 77) and OTHER (N = 44, comprising subjects with vascular dementia, Huntington's disease, schizophrenia, alcohol related cognitive impairment and a group of 'memory complainers'). Hippocampus, amygdala, entorhinal cortex, parahippocampal gyrus and cerebral cortex were rated visually on a 0-3 scale by two experienced neuroradiologists blind to clinical diagnosis.

RESULTS

Ratings of temporal lobe atrophy provided good separation between those with AD and all other groups. For example, anterior hippocampal atrophy had a sensitivity of 83% for detecting DAT, a specificity of 80% for controls, 87% for depressed subjects and 89% for OTHER. Other regions were less sensitive, but more specific for the diagnosis of DAT. In particular parahippocampal gyrus and entorhinal cortex had high specificity (97% for depressed subjects and 98% for OTHER). Because of an age-related increase in atrophy, sensitivity was highest for those over the age of 75, while specificity was highest for younger subjects. Significant correlations were observed between atrophy ratings of hippocampus, amygdala, entorhinal cortex and parahippocampal gyrus and CAMCOG memory score and length of history.

CONCLUSIONS

Temporal lobe MRI may have an important role in assisting with the clinical diagnosis of DAT, particularly its differentiation from depression and other disorders that may cause diagnostic difficulties in clinical practice.

Sequential increases in the intrahepatic expression of epidermal growth factor, basic fibroblast growth factor, and transforming growth factor beta in a bile duct ligated rat model of cirrhosis

Chronic hepatic regeneration constitutes an important part of the cirrhotic process. The factors regulating chronic hepatic regeneration, however, remain unclear. We therefore analyzed the intrahepatic messenger RNA (mRNA) expression of growth factors (epidermal growth factor [EGF], basic fibroblast growth factor [bFGF], hepatocyte growth factor [HGF], transforming growth factor [TGF]-alpha, and TGF-beta) at progressive time points (postoperative days 2, 7, 14, and 21) in a rat bile duct-ligated (BDL) model of cirrhosis versus sham controls. Intrahepatic growth factor mRNA expression was quantitatively assessed by polymerase chain reaction (PCR) using a dot-blot hybridization technique. Cirrhosis was associated with statistically significant (P < .05) progressive increases in the intrahepatic mRNA expression of bFGF (80-fold), EGF (25-fold), and TGF-beta (fourfold) in BDL animals versus controls. Furthermore, immunohistochemistry of hepatic sections showed a progressive up-regulation of bFGF protein in areas of bile duct proliferation. These areas also showed a dramatic increase in the number of hepatic stellate cells (HSC). In contrast, the intrahepatic expression of hepatocyte growth factor (HGF) mRNA was only significantly increased at postoperative days 7 and 14 in BDL animals before returning to control levels as cirrhosis developed. There were no significant differences found at any timepoint in the expression of TGF-alpha in BDL animals versus controls. In conclusion, the development of cirrhosis in this BDL rat model was associated with a progressive increase in the intrahepatic expression of EGF, bFGF, and TGF-beta. Early increased expression of HGF was not maintained in established cirrhosis. The findings suggest that these growth factors may play important roles in the pathogenesis of chronic hepatic regeneration in cirrhosis.

Degree of left hippocampal atrophy correlates with severity of neuropsychological deficits

The relationship between the degree and distribution of hippocampal atrophy measured by volumetric magnetic resonance imaging and severity of memory deficits in 25 patients with temporal lobe epilepsy secondary to mesial temporal sclerosis was assessed. Hippocampal volumes were expressed as a ratio of smaller to larger, normal ratio greater than 0.95. Neuropsychology tests included: subtests of the WAIS-R, Rey Auditory Verbal Learning Task, Rey Figure and the Austin Maze. Degree of left hippocampal atrophy in patients with left temporal lobe epilepsy was associated with severity of verbal memory deficits as measured by RAVLT total recall (P < 0.05), delayed recall (P < 0.001), story recognition (P < 0.001), list recognition (P < 0.001) and final delayed recall (P < 0.001) and recall of the Rey Figure (P < 0.01). There was no association between degree of right hippocampal atrophy and any of the memory tests. Diffuse left hippocampal atrophy was associated with more severe verbal memory deficits than anterior atrophy. We conclude, the association between degree of left hippocampal atrophy and verbal memory provides further evidence of the predominant involvement of the left hippocampus in verbal memory. The finding of a relationship between degree of left hippocampal atrophy and measures of non-verbal function suggests these tests are dependent on verbal memory, or that mesial temporal sclerosis is a bilateral but asymmetrical condition.