Longitudinal Monitoring of Quantitative Imaging Kinetics of Primary Tumor and Nodal Volumes Using the MR-Linac Device in Head and Neck Cancer Patients

PURPOSE/OBJECTIVE(S)

We aim to characterize the serial quantitative apparent diffusion coefficient (ADC) changes of the target disease volume using diffusion-weighted imaging (DWI) acquired weekly during radiation therapy (RT) on a 1.5T MR-Linac and correlate these changes with tumor response and oncologic outcomes for head and neck squamous cell carcinoma (HNSCC) patients.

MATERIALS/METHODS

Thirty patients with pathologically confirmed HNSCC and received curative-intent RT at the University of Texas MD Anderson Cancer Center, were included in this prospective study. Baseline and weekly MRIs (weeks 1-6) were obtained, and various ADC parameters (mean, 5th, 10th, 20th, 30th, 40th, 50th, 60th, 70th, 80th, 90th and 95th percentile) were extracted from the target regions of interest (ROIs). Pre-RT and weekly ADC parameters were correlated with response during RT, loco-regional control, and the development of relapse using the Mann-Whitney U test. The Wilcoxon signed-rank test was used to compare the weekly ADC versus baseline values. Weekly volumetric changes (Δvolume) for each ROI were correlated with ΔADC using Spearman's Rho test. Recursive partitioning analysis (RPA) was performed to identify the optimal ΔADC threshold associated with different oncologic outcomes.

RESULTS

There was an overall significant rise in all ADC parameters during different time points of RT compared to baseline values for both GTV-P & GTV-N. The increased ADC values for GTV-P were statistically significant only for primary tumors achieving CR during RT. RPA identified GTV-P ΔADC 5th percentile >13% at the 3rd week of RT as the most significant parameter associated with CR for GTV-P during RT (p <0.001). Baseline ADC parameters didn't significantly correlate with response to RT or other oncologic outcomes. There was a significant decrease in residual volume of both GTV-P & GTV-N throughout the course of RT. Additionally, a significant negative correlation between mean ΔADC and Δvolume for GTV-P at the 3rd and 4th week of RT was detected (r = -0.39, p = 0.044 & r = -0.45, p = 0.019, respectively).

CONCLUSION

Assessment of ADC kinetics at regular intervals throughout RT is potentially able to predict the response to RT and oncologic outcome. Further studies with larger cohorts and multi-institutional data are needed for validation of our results.

A46 ENTEROBACTERIACEAE ENRICHMENT IN THE GUT MICROBIOME OF CRITICALLY ILL PATIENTS PROMOTES IMMUNE DYSFUNCTION AND SUSCEPTIBILITY TO NOSOCOMIAL INFECTIONS

NOT PUBLISHED AT AUTHOR’S REQUEST

A29 HIGH DIMENSIONAL SINGLE CELL ANALYSIS OF IL-4 TREATED MACROPHAGES REVEALS A HETEROGENIC PHENOTYPE AND THE ABSENCE OF CD206+ SUBSETS IN CROHN'S DISEASE PATIENTS

Background

Individuals with IBD have a reduced quality of life and while treatment has improved, a cure remains elusive. Interleukin-4 differentiated macrophages (M(IL4)s) from healthy donors and IBD patients in remission promote epithelial wound repair and reduce the severity of colitis in a mouse model: findings that support the autologous transfer of M(IL4)s to treat IBD. However, issues remain if this novel therapy is to advance to clinical evaluation: a much greater understanding of the possible heterogeneity within the human M(IL4) population, the biology of any sub-groups therein and the biology of any M(IL4) subtypes is needed.

Purpose

To determine if cryopreservation, sex, and disease status in Crohn's disease (CD) impact the phenotype and function of M(IL4)

Method

Blood mononuclear cells were collected from healthy donors, and individuals with active CD or in remission (n=6/group), and differentiated to macrophages with GMP-grade recombinant human M-CSF (10 ng/ml, 7 days). Macrophages (2.5 x10⁵) were activated with IL-4 (10ng/ml, 48h). Fresh and cryopreserved M(0) and M(IL4) were stained using a panel of 18 metal-conjugated antibodies. Data were acquired on a Helios CyTOFII mass cytometer. FCS files were imported into Cytobank for manual gating (viable CD45⁺CD3^-CD19^- singlet cell events) and exported for meta-clustering in R with the CATALYST package using the FlowSOM function with 10 metaclusters.

Result(s)

FlowSOM analysis on M(IL4) from healthy donors indicated clear differences between M(0) and M(IL4), with 8 metaclusters >1.5% of M(IL4)s: the most abundant metaclusters express high and intermediate CD206, PDL1, CD11b, CD33, CD64, HLA-DR and low CD14 levels. There were no significant differences in these M(IL4)s metaclusters between males and females, or fresh vs. cryopreserved cells using this characterization strategy. M(IL4) from patients with active CD, were markedly different with the absence of three high-intermediate CD206⁺PDL1⁺ metaclusters and a general lack of CD206⁺ metaclusters compared to healthy controls. Surprisingly, and despite M(IL4)s from CD patients in remission showing increased CD206 mRNA, CYTOF analysis revealed that the macrophages were more similar to those from individuals with active disease than those from healthy controls

Conclusion(s)

Here human macrophages activated with IL4 in vitro are revealed as a heterogeneous population, and subsets characterized by increased high CD206 expression are generally absent in active Crohn’s disease. Intriguing while prior experiments with M(IL4) from CD patients in remission reduced the severity of colitis in rag1^-/- mice, the characterization of these cells via 18 protein markers indicates they are more like M(IL4)s from patients with active disease compared to healthy controls. While presenting autologous M(IL4) transfer as a novel approach for IBD, a much fuller understanding of the phenotype and function of M(IL4)s (and sub-populations therein) is required before this would become a therapeutic option

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CAG

Disclosure of Interest

None Declared

Genome-scale phylogenies reveal relationships among Parastagonospora species infecting domesticated and wild grasses

Several plant pathogenic Parastagonospora species have been identified infecting wheat and other cereals over the past 50 years. As new lineages were discovered, naming conventions grew unwieldy and the relationships with previously recognized species remained unclear. We used genome sequencing to clarify relationships among these species and provided new names for most of these species. Six of the nine described Parastagonospora species were recovered from wheat, with five of these species coming from Iran. Genome sequences revealed that three strains thought to be hybrids between P. nodorum and P. pseudonodorum were not actually hybrids, but rather represented rare gene introgressions between those species. Our data are consistent with the hypothesis that P. nodorum originated as a pathogen of wild grasses in the Fertile Crescent, then emerged as a wheat pathogen via host-tracking during the domestication of wheat in the same region. The discovery of a diverse array of Parastagonospora species infecting wheat in Iran suggests that new wheat pathogens could emerge from this region in the future. Citation: Croll D, Crous PW, Pereira D, et al. 2021. Genome-scale phylogenies reveal relationships among Parastagonospora species infecting domesticated and wild grasses. Persoonia 46: 116-128. https://doi.org/10.3767/persoonia.2021.46.04.

Medical Care Disruptions During the First Six-Months of the COVID19 Pandemic: The Experience of Older Breast Cancer Survivors

Purpose.

Older cancer survivors required medical care during the COVID-19 pandemic despite infection risks, but there are limited data on medical care in this age group.

Methods.

We evaluated care disruptions in a longitudinal cohort of non-metastatic breast cancer survivors ages 60–98 from five US regions (n=321). Survivors completed a web-based or telephone survey from May 27, 2020 to September 11, 2020. Care disruptions included self-reported interruptions in ability to see doctors, receive treatment or supportive therapies, or fill prescriptions. Logistic regression models evaluated bivariate and multivariate associations between care disruptions and education, medical, psychosocial and COVID-19-related factors. Multivariate models included age, county COVID-19 rates, comorbidity and post-diagnosis time.

Results.

There was a high response rate (n=262, 81.6%). Survivors were 32.2 months post-diagnosis (SD 17.5, range 4–73). Nearly half (48%) reported a medical disruption. The unadjusted odds of care disruptions were significantly higher with more education (OR 1.23 per one-year increase, 95% CI 1.09–1.39, p =0.001) and greater depression (OR 1.04 per one-point increase in CES-D score, CI 1.003–1.08, p=0.033); tangible support decreased the odds of disruptions (OR 0.99, 95% CI 0.97–0.99 per one-point increase, p=0.012). There was a trend for associations between disruptions and comorbidity (unadjusted OR 1.13 per 1 added comorbidity, 95% CI 0.99–1.29, p=0.07). Adjusting for covariates, only higher education (p=0.001) and tangible social support (p=0.006) remained significantly associated with having care disruptions.

Conclusions.

Older breast cancer survivors reported high rates of medical care disruptions during the COVID-19 pandemic and psychosocial factors were associated with care disruptions.

A-05 Self-Reported Symptomatology in Athletes with Autism Diagnosis

Objective

To examine the relationship between athletes with and without Autism diagnosis and self-reported symptoms as measured by ImPACT.

Method

Participants were selected from an archival de-identified sports medicine ImPACT database. The sample (N = 232) was primarily male (72.4%) student athletes with a mean age of 15.41 years (SD = 1.292). Participants were divided into two groups: Autism diagnosis (n = 130); No diagnosis (n = 102). An independent samples t-test was conducted to analyze the variation of self-reported symptoms between athletes with and without an Autism diagnosis.

Results

The independent samples t-test revealed significant differences between diagnostic groups and self-reported cognitive (t = 5.832, p &lt; .001, d = .72); sleep (t = 4.040, p &lt; .001, d = .51); vestibular somatic (t = 4.154, p &lt; .001, d = .53); and affective symptomatology (t = 3.988, p &lt; .001, d = .51). Athletes with a diagnosis of Autism reported more symptoms overall in comparison to athletes without a diagnosis.

Conclusions

These findings suggest that prior psychological diagnoses play a significant role in symptom scores; however, the degree to which these symptoms can be attributed to the diagnosis itself or the concussion is unknown. It should be noted that individuals who have been diagnosed with Autism may already be at an increased risk of sleep difficulties, emotional regulation, and sensory stimulation within the environment. Therefore, differentiating the symptom scores from preexisting symptoms of Autism from a concussion can be beneficial when helping athletes return to play.

B-41 SPECT Differences between Obsessive Compulsive Disorder and Post-Traumatic Stress Disorder (PTSD)

Objective

To assess whether diagnosed Obsessive Compulsive Disorder (OCD) and Post Traumatic Stress Disorder (PTSD) interactively alter brain activity, as measured by a Single Photon Emission Computed Tomography (SPECT) imaging.

Method

The sample included adults diagnosed with OCD (n = 915) with a mean age of 34.65 and predominantly male (68.6%) and adults with PTSD (n = 1,481) which had a mean age of 41.33 and was predominantly female (57.2%). Significant differences were observed for gender . Multiple ANCOVAs were conducted to determine differences between cerebral blood flow (CBF)in 17 different brain regions.

Results

Results showed hyper-perfusion in the PTSD group as compared to the OCD group in the pariental L/R[F(1,2393) = 6.47,p < 0.01/F(1,2393) = 12.31,p < .01], motor sensory L/R[F(1,2393) = 19.33,p < .001/F(1,2393) = 17.32,p < .01] and temporal left [F(1,2393) = 12.49,p < .01].

Conclusion

Significantly higher rCBF in the pariental and motor sensory for OCD individuals may be due to visual-constructive and controlled fluency which are usually associated with compulsion. Due to the hyperalert nature related with OCD rituals, these areas are more active when compared to PTSD. Hyperfusion was reported for PTSD in the left temporal lobe compared to OCD, this region is usually associated with registering potential threasts in the environment. This can be explained by the hypervigilant conduct seen in individuals with PTSD. Overall, it appears that individuals with OCD struggle with continual inability to inhibit repetitive thoughts and behaviors due to the over activation in the motor sensory and parietal region. Alternatively, the activation in PTSD individuals can be a result of a way to help them cope with threats in the environment.

B-08 Cerebral Blood Flow Differences at Baseline Between Cortical Regions in Tic Disorders Population

Objective

To identify CBF differences between individuals with Tic Disorder and healthy controls.

Methods

The data for this study was acquired from a de-identified archival Single-Photon Emission Computed Tomography (SPECT) database. The sample included a healthy control group (n = 83,age M = 42.02,54.22% female) and a second group included individuals diagnosed with Tic Disorder (n = 177,age M = 33.54,83.05% male). Significant differences were found for gender [χ(2) = 41.16,p < .001] between groups. As a result, ANCOVAs were conducted to measure CBF differences across the brain using SPECT scans between the two groups while controlling for gender.

Results

Results showed significant differences between the two groups and perfusion in 4 brain regions. Hypo-perfusion in the Tic Disorder group was observed in the right basal ganglia [F(1,260) = 30.959,p < .001] and left [F(1,260) = 32.16,p < .001]. Hyper-perfusion was found in the right cerebellum [F(1,260) = 16.63,p < .001], and left [F(1,260) = 22.17,p < .001] in the same group.

Conclusion

Results indicate that individuals with tic disorders have diminished CBF than healthy controls in both sides of the basal ganglia. This contrasts previous studies, which have shown that individuals with tic disorders have more CBF in the basal ganglia. Further research is needed to understand this inconsistency; a possible explanation is that there is an inhibiting effect on the basal ganglia. Increased CBF in both sides of the cerebellum supports previous research as this cortical area has been shown to have connections with the basal ganglia, activating the pathway that trigger the motor tics. Tic disorders are usually associated with other comorbidities therefore the sample may have other diagnoses that affect blood flow. Future research should control for potential comorbidities.

Patients With a Prolonged Intensive Care Unit Length of Stay Have Decreased Health-Related Quality of Life After Cardiac Surgery

Cardiac surgery patients with a prolonged ICU length of stay (prICULOS) have lower rates of functional survival following their procedure, however detailed information on their health related quality of life (HRQoL) is lacking. We sought to investigate the potential need for intervention in these high-risk patients through comprehensive HRQoL assessments in the months to year following their surgery. A prospective, observational pilot study was undertaken and cardiac surgery patients with a prICULOS (ICU length of stay of ≥5 days) were recruited. A control group was obtained through recruitment of cardiac surgery patients with an ICU length of stay of <5 days. In-person clinical or telephone survey HRQoL assessments were completed at 3-6 months and 1-year time points after their procedure. The standardized mean difference (SMD) was calculated for all study variable comparisons to quantify the standardized effect size observed between non-prICULOS and prICULOS patients. 789 cardiac procedures were performed during the study period and 89 patients experienced a prICULOS (10.7%). Of these 89 patients, 35 prICULOS patients were recruited along with 35 controls. 29 out of 35 prICULOS patients completed the study (83%). At the 3-6 month follow up the prICULOS patients had higher levels of weight loss, fear of falling, and driving deficits. At 1-year, prICULOS patients had persistent difficulties with activities of daily living and required more family and external support. This study demonstrates the need for closer follow up and intervention for cardiac surgery patients with a prICULOS who were found to have poorer mid and long-term HRQoL.

Predictors of vitamin D status in New Zealand preschool children

Vitamin D deficiency has adverse health effects in young children. Our aims were to determine predictors of vitamin D status and then to use these factors to develop a practical tool to predict low 25(OH)D concentrations in preschool New Zealand children. A cross-sectional sample of 1329 children aged 2 to <5 years were enrolled from throughout New Zealand in late-winter to spring 2012. 25-Hydroxyvitamin D (25(OH)D) was measured on dried blood spot (DBS) samples collected using finger-prick sampling. Caregivers completed a questionnaire. Mean (SD) DBS 25(OH)D concentration was 52(19)nmol/L. 25(OH)D < 25 nmol/L was present in 86(7%), 25(OH)D < 50 nmol/L in 642(48%), 25(OH)D 50- < 75 nmol/L in 541(41%) and 25(OH)D > 75 nmol/L in 146(11%) of children. Factors independently associated with the risk of 25(OH)D < 25 nmol/L were female gender (OR 1.92,95%CI 1.17-3.14), other non-European ethnicities (not including Māori or Pacific) (3.51,1.89-6.50), had olive-dark skin colour (4.52,2.22-9.16), did not take vitamin D supplements (2.56,1.06-6.18), had mothers with less than secondary-school qualifications (5.00,2.44-10.21) and lived in more deprived households (1.27,1.06-1.53). Children who drank toddler milk (vitamin D fortified cow's milk formula marketed to young children) had a zero risk of 25(OH)D < 25 nmol/L. The predictive tool identified children at risk of 25(OH)D < 25 nmol/L with sensitivity 42%, specificity 97% and ROC area-under-curve 0.76(95%CI 0.67-0.86, p < 0.001). Predictors of low vitamin D status were consistent with those identified in previous studies of New Zealand children. The tool had insufficient predictive ability for use in clinical situations, and suggests a need to promote safe, inexpensive testing to determine vitamin D status in preschool children.

Short Communication: The Pre-transport management of antemortem stress in cattle: Impact on carcass yield

Grumpelt, B., Hoffer, W., Curie, O., Jones, O., Jones, K., Kimmel, D., McDonald, B., Paterson, R. and Schaefer, A. 2015. Short Communication:The Pre-transport management of antemortem stress in cattle: Impact on carcass yield. Can. J. Anim. Sci. 95: 557–560. Transport and handling of cattle can have a significant impact on carcass weight loss. The purpose of the present study was to examine the effect of providing pre-transport nutritional therapy containing selective amino acids, electrolytes and an energy source, on carcass weight loss. One hundred and ninety British crossbred steers averaging 611 kg were used in the study. The treatment cattle received 1 kg of a nutritional supplement top dressed onto their normal silage diet 24 h prior to transport. Following a 1-h transport period the cattle were processed at a federally inspected beef plant and both hot and cold carcass yield as well as yield grade and quality grade were assessed. Cattle provided with pre-transport nutritional therapy demonstrated a reduction in percentage live weight loss (P<0.01) as well as 1.2% greater hot carcass yield as a proportion of pre-treatment farm weight (P<0.01). The data suggest the use of nutritional support pre-transport is beneficial to carcass yield.

Acetic acid recovery from a hybrid biological-hydrothermal treatment process of sewage sludge - a pilot plant study

A two-stage process consisting of anaerobic fermentation followed by sub-critical wet oxidation was used to generate acetic acid from sewage sludge at pilot scale. Volatile fatty acids, dominated by propionic acid, were produced over 4-6 days in the 2,000 L fermentation reactor, which also achieved 31% solids reduction. Approximately 96% of the carbon was retained in solution over the fermentation stage. Using a 200 L wet oxidation reactor operating in batch mode, the second stage achieved 98% volatile suspended solids (VSS) destruction and 67% total chemical oxygen demand (tCOD) destruction. Acetic acid produced in this stage was recalcitrant to further degradation and was retained in solution. The gross yield from VSS was 16% for acetic acid and 21% for volatile fatty acids across the process, higher than reported yields for wet oxidation alone. The pilot plant results showed that 72% of the incoming phosphorus was retained in the solids, 94% of the nitrogen became concentrated in solution and 41% of the carbon was converted to a soluble state, in a more degradable form. Acetic acid produced from the process has the potential to be used to offset ethanol requirements in biological nutrient removal plants.

Combined thermochemical and fermentative destruction of municipal biosolids: a comparison between thermal hydrolysis and wet oxidative pre-treatment

In this study the comparative destruction of municipal biosolids using thermal hydrolysis (140 or 165°C) and wet oxidation (220°C) was followed by biological degradation via mesophilic anaerobic digestion (36°C). Wet oxidation (WO) destroyed more than 93% of the VSS, while thermal hydrolysis (TH) at 140 and 165°C destroyed 9% and 22%, respectively. Combined TH and anaerobic digestion resulted in approximately 50% VSS destruction. The ultimate methane potential of the combined fractions from the thermal hydrolysis at 140 and 165°C improved by 12-13% relative to the untreated control sample. Methane production from the WO material was 53% of the control yield and wholly attributable to soluble organic carbon in the liquid fraction, indicating that the WO destroyed all putrescible carbon from the solids fraction. Point sampling during the BMP assay revealed that methanogenic development, not solids hydrolysis, was the kinetic barrier during anaerobic digestion in this study.

Enhancing denitrification using a carbon supplement generated from the wet oxidation of waste activated sludge

This study compared the effect of four pure carbon supplements on biological denitrification to a liquor derived as a by-product from the wet oxidation (WO) of waste activated sludge. Sequencing batch reactors were used to acclimate sludge biomass, which was used in batch assays. Acetate, WO liquor and ethanol-supplementation generated the fastest denitrification rates. Acetate and WO liquor were efficiently utilised by all acclimated biomass types, while poor rates were achieved with methanol and formate. When comparing an inoculum from an ethanol-supplemented and non-supplemented wastewater treatment plant (WWTP), the ethanol-acclimated sludge obtained superior denitrification rates when supplemented with ethanol. Similarly high nitrate removal rates were achieved with both sludge types with acetate and WO liquor supplementation, indicating that WO liquors could achieve excellent rates of nitrate removal. The performance of the WO liquor was attributed to the variety of organic carbon substrates (particularly acetic acid) present within the liquor.

A Cardiac Sound Reproduction Apparatus for Improved Stethoscope Testing

Valvular heart disease is a significant problem. The primary case physician initially does assessment through auscultation. Accuracy in classification of sounds is suboptimal (20 to 40%). Lower frequencies of heart sounds are important in classification of murmurs associated with valvular heart disease. We find stethoscope sound intensity capture falls significantly at the 1500 Hz range and lower. Strategies to improve auscultation accuracy include improving stethoscope features or developing a device that, when used with the stethoscope, augments sound capturing abilities at lower frequencies. Testing necessitated development of a reliable (without significant intra-sound variation) cardiac sound reproduction device. A sound permeable contracting polymer when used with a stethoscope signficantly increases sound intensity captured in the 625 Hz to 1500 Hz range, when tested with a reliable cardiac sound reproduction device. We prepared an air-sealed device with an amplifier, four internal speakers capable of emitting high quality, low frequency sounds, and a listening pad. An existing electronic stethoscope with, and then without, a sound permeable contracting polymer captured three sounds (normal, innocent systolic murmur, pathological systolic murmur) five times per sound. The sounds were placed in computer files. FFTs were constructed. Sound intensity within the 625 Hz to 1400 Hz range, when the sound permeable contracting polymer is used with the electronic stethoscope, relatively improves, on average, approximately 11 dB, compared to sound captured with the same electronic stethoscope without the sound permeable contracting polymer. This difference is numerically statistically significant (p<0.001). Intra-sound variability testing (standard deviation) of FFTs was not significant. A sound permeable contracting polymer used with an electronic recording stethoscope significantly improves sound intensity in an important auscultation frequency range. Intra-sound testing variation was insignificant. A study is underway to demonstrate impact using an absolute reference point. However, as amplification within existing electronic stethoscopes is commercially available, potential variation in relative reference points may be overcome with existing amplification features on electronic stethoscopes, allowing improved capture of heart sounds within the 625 Hz to 1400 Hz range. Limitations include the need for human subject study. Further testing, including human subjects testing is needed prior to application for FDA approval. FDA approval is needed before any use on humans. The methodology should not be utilized clinically without FDA approval.

Variations in behavior and condition of a Southern Ocean top predator in relation to in situ oceanographic conditions

Responses by marine top predators to environmental variability have previously been almost impossible to observe directly. By using animal-mounted instruments simultaneously recording movements, diving behavior, and in situ oceanographic properties, we studied the behavioral and physiological responses of southern elephant seals to spatial environmental variability throughout their circumpolar range. Improved body condition of seals in the Atlantic sector was associated with Circumpolar Deep Water upwelling regions within the Antarctic Circumpolar Current, whereas High-Salinity Shelf Waters or temperature/salinity gradients under winter pack ice were important in the Indian and Pacific sectors. Energetic consequences of these variations could help explain recently observed population trends, showing the usefulness of this approach in examining the sensitivity of top predators to global and regional-scale climate variability.

Size of hippocampal pyramidal neurons in schizophrenia

BACKGROUND

Meta-analyses of hippocampal size have indicated that this structure is smaller in schizophrenia. This could reflect a reduction in the size of constituent neurons or a reduced number of neurons.

AIMS

To measure the size of hippocampal pyramidal neurons in the brains of people with and without schizophrenia.

METHOD

Pyramidal neuron size in hippocampal subfields was estimated stereologically from sections taken at 5 mm intervals throughout the whole length of right and left hippocampi from the brains of 13 people with schizophrenia and 16 controls. Results were assessed using repeated-measures analysis of covariance looking for a main effect of diagnosis and gender, and interactions of these with side.

RESULTS

We were unable to detect significant differences related to diagnosis, gender or side for any hippocampal subfield for this series of cases.

CONCLUSIONS

For this series of brains, hippocampal cell size is unchanged in schizophrenia.

Synaptic pathology in prefrontal cortex is present only with severe dementia in Alzheimer disease

Synaptic pathology is proposed to be integral to the clinical expression of Alzheimer disease (AD). Most studies have assessed only the vesicle protein synaptophysin as a measure of synaptic integrity. The interrelationships of synaptophysin, other presynaptic proteins, the cholinergic system, and severity of dementia in AD remain unclear. We studied the presynaptic proteins synaptophysin, syntaxin and SNAP-25, along with choline acetyltransferase (ChAT) activity in prefrontal cortex (BA 46) samples from 18 subjects with AD and 16 controls. Mean values of presynaptic protein immunoreactivities were significantly reduced, by 21%-28%, and ChAT activity was reduced by 41% in the AD groups. Synaptic protein immunoreactivity and ChAT activity were correlated with Mini-Mental State Examination scores obtained 1 yr prior to death. When AD cases were subgrouped into mild/moderate and severe illness at time of death, all differences in presynaptic proteins and ChAT activity were significant between controls and severe cases. However, no significant differences were detected in BA 46 between controls and mild/moderate cases. Considerable synaptic reserve or plasticity remains in BA 46 until the late stages of AD. Synaptophysin and ChAT appear to be more vulnerable in severe AD than are syntaxin or SNAP-25.

A randomized clinical trial of continuous versus intermittent dialysis for acute renal failure

BACKGROUND

Acute renal failure (ARF) requiring dialysis in critically ill patients is associated with an in-hospital mortality rate of 50 to 80%. The worldwide standard for renal replacement therapy is intermittent hemodialysis (IHD). Continuous hemodialysis and hemofiltration techniques have recently emerged as alternative modalities. These two therapies have not been directly compared.

METHODS

A multicenter, randomized, controlled trial was conducted comparing two dialysis modalities (IHD vs. continuous hemodiafiltration) for the treatment of ARF in the intensive care unit (ICU). One hundred sixty-six patients were randomized. Principal outcome measures were ICU and hospital mortality, length of stay, and recovery of renal function.

RESULTS

Using intention-to-treat analysis, the overall ICU and in-hospital mortalities were 50.6 and 56.6%, respectively. Continuous therapy was associated with an increase in ICU (59.5 vs. 41.5%, P < 0.02) and in-hospital (65.5 vs. 47.6%, P < 0.02) mortality relative to intermittent dialysis. Median ICU length of stay from the time of nephrology consultation was 16.5 days, and complete recovery of renal function was observed in 34.9% of patients, with no significant group differences. Despite randomization, there were significant differences between the groups in several covariates independently associated with mortality, including gender, hepatic failure, APACHE II and III scores, and the number of failed organ systems, in each instance biased in favor of the intermittent dialysis group. Using logistic regression to adjust for the imbalances in group assignment, the odds of death associated with continuous therapy was 1.3 (95% CI, 0.6 to 2.7, P = NS). A detailed investigation of the randomization process failed to explain the marked differences in patient assignment.

CONCLUSIONS

A randomized controlled trial of alternative dialysis modalities in ARF is feasible. Despite the potential advantages of continuous techniques, this study provides no evidence of a survival benefit of continuous hemodiafiltration compared with IHD. This study did not control for other major clinical decisions or other supportive management strategies that are widely variable (for example, nutrition support, hemodynamic support, timing of initiation, and dose of dialysis) and might materially influence outcomes in ARF. Standardization of several aspects of care or extremely large sample sizes will be required to answer optimally the questions originally posed by this investigation.

Schizophrenia and the frontal lobes: post-mortem stereological study of tissue volume

BACKGROUND

It has been suggested that there is frontal lobe involvement in schizophrenia, and that it may be lateralised and gender-specific.

AIMS

To clarify the structure of the frontal lobes in schizophrenia in a post-mortem series.

METHOD

The volume of white matter and cortical components of the frontal lobes was measured in brains of controls and patients with schizophrenia using planimetry and the Cavalieri principle. The components measured were: superior frontal gyrus, middle frontal gyrus, a composite of inferior frontal gyrus and orbito-frontal cortex, as well as total frontal lobe cortex and white matter. In addition, the anterior cingulate gyrus was measured.

RESULTS

No diagnosis, gender, diagnosis x side, diagnosis x gender or diagnosis x gender x side interactions were observed in the volume of any of the components, the grey matter as a whole or the white matter. No evidence for volumetric inter-group differences was found for the anterior cingulate gyrus.

CONCLUSIONS

Such structural abnormalities as are present in the frontal lobes are more subtle than straightforward alterations in tissue volume; they may include changes in shape and the pattern of gyral folding.

Steroid responsive polyneuropathy in a family with a novel myelin protein zero mutation

OBJECTIVE

To report a novel hereditary motor and sensory neuropathy (HMSN) phenotype, with partial steroid responsiveness, caused by a novel dominant mutation in the myelin protein zero (MPZ) gene. Most MPZ mutations lead to the HMSN type I phenotype, with recent reports of Déjérine-Sottas, congenital hypomyelination, and HMSN II also ascribed to MPZ mutations. Differing phenotypes may reflect the effect of particular mutations on MPZ structure and adhesivity.

METHODS

Clinical, neurophysiological, neuropathological, and molecular genetic analysis of a family presenting with an unusual hereditary neuropathy.

RESULTS

Progressive disabling weakness, with positive sensory phenomena and areflexia, occurred in the proband with raised CSF protein and initial steroid responsiveness. Nerve biopsy in a less severely affected sibling disclosed a demyelinating process with disruption of compacted myelin. The younger generation were so far less severely affected, becoming symptomatic only after 30 years. All affected family members were heterozygous for a novel MPZ mutation (Ile99Thr), in a conserved residue.

CONCLUSIONS

This broadens the range of familial neuropathy associated with MPZ mutations to include steroid responsive neuropathy, initially diagnosed as chronic inflammatory demyelinating polyneuropathy.

Cholinergic deficits contribute to behavioral disturbance in patients with dementia

BACKGROUND

Noncognitive behavioral changes such as depression, aggressive behavior, psychosis, and overactivity occur frequently in patients with dementia, in addition to cognitive impairment, and often determine the need for institutionalization. The biochemical basis of such changes is poorly understood. Clinical trial data indicate that cholinomimetics improve noncognitive behaviors. This study investigated the relationship between markers of the cholinergic and dopaminergic neurotransmitter systems and noncognitive behavioral symptoms assessed during the course of dementing illness.

METHOD

Brains from 46 patients with dementia (36 with AD and 10 with mixed or other dementias using Consortium to Establish a Registry for AD criteria) were examined together with 32 normal controls. The patients with dementia had been evaluated every 4 months, often over several years, for cognitive performance (Mini-Mental State Examination) and behavior (Present Behavioral Examination). Concentrations of dopamine (DA) and major metabolites, choline acetyltransferase activity (ChAT), and density (Bmax) of DA D1 receptors in frontal and temporal cortex were studied by radioligand binding protocols. None of the patients was receiving cholinomimetic drugs.

RESULTS

ChAT activity, but no other neurochemical markers, was reduced in AD compared with controls. Loss of ChAT activity correlated with cognitive impairment. Lowered ChAT activity also correlated with increasing overactivity in patients with dementia in both frontal and temporal cortex whereas ChAT:DA and ChAT:D1 ratios in temporal cortex correlated negatively with aggressive behavior.

CONCLUSIONS

Disturbance of the cholinergic system may underlie both cognitive and some noncognitive behavioral changes in dementia, providing a basis for rational therapy.-1467