Search

Alzheimer’s disease (AD) is the most common cause of dementia in older adults. Neuropathological and imaging studies have demonstrated a progressive and stereotyped accumulation of protein aggregates, but the underlying molecular and cellular mechanisms driving AD progression and vulnerable cell populations affected by disease remain coarsely understood. The current study harnesses single cell and spatial genomics tools and knowledge from the BRAIN Initiative Cell Census Network to understand the impact of disease progression on middle temporal gyrus cell types. We used image-based quantitative neuropathology to place 84 donors spanning the spectrum of AD pathology along a continuous disease pseudoprogression score and multiomic technologies to profile single nuclei from each donor, mapping their transcriptomes, epigenomes, and spatial coordinates to a common cell type reference with unprecedented resolution. Temporal analysis of cell-type proportions indicated an early reduction of Somatostatin-expressing neuronal subtypes and a late decrease of supragranular intratelencephalic-projecting excitatory and Parvalbumin-expressing neurons, with increases in disease-associated microglial and astrocytic states. We found complex gene expression differences, ranging from global to cell type-specific effects. These effects showed different temporal patterns indicating diverse cellular perturbations as a function of disease progression. A subset of donors showed a particularly severe cellular and molecular phenotype, which correlated with steeper cognitive decline. We have created a freely available public resource to explore these data and to accelerate progress in AD research atSEA-AD.org.

Human brain tissue has long been a critical resource for neuroanatomy and neuropathology, but with the advent of advanced imaging and molecular sequencing techniques, it has become possible to use human brain tissue to study, in great detail, the structural, molecular, and even functional underpinnings of human brain disease. In the century following the first description of Alzheimer's disease (AD), numerous technological advances applied to human tissue have enabled novel diagnostic approaches using diverse physical and molecular biomarkers, and many drug therapies have been tested in clinical trials (Schachter and Davis, Dialogues Clin Neurosci 2:91-100, 2000). The methods for brain procurement and tissue stabilization have remained somewhat consistently focused on formalin fixation and freezing. Although these methods have enabled research protocols of multiple modalities, new, more advanced technologies demand improved methodologies for the procurement, characterization, stabilization, and preparation of both normal and diseased human brain tissues. Here, we describe our current protocols for the procurement and characterization of fixed brain tissue, to enable systematic and precisely targeted diagnoses, and describe the novel, quantitative molecular, and neuroanatomical studies that broadly expand the use of formalin-fixed, paraffin-embedded (FFPE) tissue that will further our understanding of the mechanisms underlying human neuropathologies.

The vast majority of archived research and clinical pathological specimens are stored in the form of formalin fixed, paraffin-embedded (FFPE) tissues, but, unlike fresh frozen tissue samples, highly quantitative measures in FFPE tissues are limited to immunohistochemical and immunofluorescence thresholding image analysis studies, cell counting, and ordinal ranking systems. This poses a significant obstacle for clinical investigations that aim to correlate diagnostic markers of neurodegenerative diseases like Alzheimer's disease (AD) with parameters like age, gender, drug exposures, genotype, disease stage, co-morbidities, or environmental factors. To overcome this limitation, we have developed Luminex-based techniques and protocols for the quantification of amyloid β and hyperphosphorylated Tau in FFPE brain sections. We validated the Luminex assay in FFPE sections from prefrontal cortex, hippocampus, and neostriatum from 30 cases that underwent prior neuropathological diagnostic assessment of AD following the current NIA-AA recommendations for AD: 10 cases diagnosed as not or low, 10 cases as intermediate, and 10 cases as high AD neuropathologic change. Consistent with the neuropathologic assessment, Luminex assay detected high amounts of amyloid beta in the frontal cortex and striatum, and high amounts of hyperphosphorylated Tau in the frontal cortex and hippocampus, of cases with high AD neuropathologic change. This assay can be expanded to detect diverse antigenic targets of interest, as we show here with IBA1 and GFAP. This novel approach supports multiplexed highly quantitative, molecularly specific neuropathology measures to further explore mechanisms of neurodegeneration in AD.

Introduction Nonhuman primates may serve as excellent models of sporadic age-associated brain β-amyloid deposition and Alzheimer's disease pathologic changes. We examined whether a vervet nonhuman primate model recapitulated pathologic, physiologic, and behavioral features of early Alzheimer's disease. Methods Nine middle-aged (mean = 11.2 years) and nine aged (mean = 21.7 years) female vervet/African green monkeys underwent cerebrospinal fluid collection, gait speed measurement, and neuroimaging before neuropathologic assessment. Results β-amyloid plaques were identified in all aged vervets and paired helical filament tau immunoreactivity was observed in all animals. Cerebrospinal fluid β-amyloid42 and gait speed correlated negatively with age and plaque density. Greater plaque and paired helical filament tau burden predicted reduced volumes and CMRg in several brain regions. Discussion We observed a coordinated set of relationships among neuropathologic, cerebrospinal fluid, imaging, and behavioral modalities consistent with early Alzheimer's disease. Our results support future use of the vervet model to explore disease mechanisms, biomarkers, and novel therapeutic strategies.

Background The objective of this study was to make a quantitative comparison of flortaucipir PET retention with pathological tau and β-amyloid across a range of brain regions at autopsy. Methods Patients with dementia (two with clinical diagnosis of AD, one undetermined), nearing the end of life, underwent 20-min PET, beginning 80 min after an injection of ~370 mBq flortaucipir [18F]. Neocortical, basal ganglia, and limbic tissue samples were obtained bilaterally from 19 regions at autopsy and subject-specific PET regions of interest corresponding to the 19 sampled target tissue regions in each hemisphere were hand drawn on the PET images. SUVr values were calculated for each region using a cerebellar reference region. Abnormally phosphorylated tau (Ptau) and amyloid-β (Aβ) tissue concentrations were measured for each tissue region with an antibody capture assay (Histelide) using AT8 and H31L21 antibodies respectively. Results The imaging-to-autopsy interval ranged from 4–29 days. All three subjects had intermediate to high levels of AD neuropathologic change at autopsy. Mean cortical SUVr averaged across all three subjects correlated significantly with the Ptau immunoassay (Pearson r = 0.81; p < 0.0001). When Ptau and Aβ1-42 were both included in the model, the Ptau correlation with flortaucipir SUVr was preserved but there was no correlation of Aβ1-42 with flortaucipir. There was also a modest correlation between limbic (hippocampal/entorhinal and amygdala) flortaucipir SUVr and Ptau (Pearson r = 0.52; p < 0.080). There was no significant correlation between SUVr and Ptau in basal ganglia. Conclusions The results of this pilot study support a quantitative relationship between cortical flortaucipir SUVr values and quantitative measures of Ptau at autopsy. Additional research including more cases is needed to confirm the generalizability of these results. Trial registration, NIH Clinicaltrials.gov NCT # 02516046. Registered August 27, 2015. https://clinicaltrials.gov/ct2/show/NCT02516046?term=02516046&draw=2&rank=1

As more people live longer, age-related neurodegenerative diseases are an increasingly important societal health issue. Treatments targeting specific pathologies such as amyloid beta in Alzheimer’s disease (AD) have not led to effective treatments, and there is increasing evidence of a disconnect between traditional pathology and cognitive abilities with advancing age, indicative of individual variation in resilience to pathology. Here, we generated a comprehensive neuropathological, molecular, and transcriptomic characterization of hippocampus and two regions cortex in 107 aged donors (median = 90) from the Adult Changes in Thought (ACT) study as a freely-available resource (http://aging.brain-map.org/). We confirm established associations between AD pathology and dementia, albeit with increased, presumably aging-related variability, and identify sets of co-expressed genes correlated with pathological tau and inflammation markers. Finally, we demonstrate a relationship between dementia and RNA quality, and find common gene signatures, highlighting the importance of properly controlling for RNA quality when studying dementia.

Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons and produces a movement disorder and cognitive impairment that becomes more extensive with the duration of the disease. To what extent cognitive impairment in advanced PD can be attributed to severe loss of dopamine (DA) signaling is not well understood. Furthermore, it is unclear if the loss of DA neurons contributes to the cognitive impairment caused by the reduction in DA signaling. We generated genetic mouse models with equally severe chronic loss of DA achieved by either extensive ablation of DA neurons or inactivation of DA synthesis from preserved neurons and compared their motor and cognitive performance. Motor behaviors were equally blunted in both models, but we observed that DA neuron ablation caused more severe cognitive deficits than DA depletion. Both models had marked deficits in cue-discrimination learning. Yet, deficits in cue-discrimination learning were more severe in mice with DA neuron ablation and only mice with DA neuron ablation had drastically impaired performance in spatial learning, spatial memory and object memory tests. These results indicate that while a severe reduction in DA signaling results in motor and cognitive impairments, the loss of DA neurons promotes more extensive cognitive deficits and suggest that a loss of additional factors that depend on DA neurons may participate in the progressive cognitive decline found in patients with PD.

Parkinson's disease (PD) and Alzheimer's disease (AD) are recognized to coexist on a spectrum of neurodegeneration, and it has been proposed that molecular interactions among pathogenic proteins are a basis for the overlap between these two diseases. We instead hypothesize that degeneration of the nigro-striatal dopaminergic system enhances the clinical penetrance of early stage AD. To determine the effect of striatal dopamine on the pathological effects in an experimental model of AD, APPSWE/PS1ΔE9 mice received striatal injections of the neurotoxin 6-hydroxydopamine (6OHDA). Animals were tested in a Barnes maze protocol and a water T-maze protocol at different ages to determine the onset of cognitive impairment. APPSWE/PS1ΔE9 mice that received 6OHDA injections showed significant impairment in Barnes maze performance at an earlier age than controls. Additionally, at 12 months of age APPswe/PS1ΔE9+6OHDA mice demonstrated worse behavioral flexibility in a task-switch phase of the water T-maze than other groups. To determine the neuroprotective effects of dopaminergic neurotransmission against Aβ42 toxicity, neuronal branch order and dendrite length was quantified in primary medium spiny neuron (MSN) cultures pretreated with increasing doses of the D1 and D2 receptor agonists before being exposed to oligomerized Aβ42. While there was no difference in Aβ peptide levels or plaque burden between groups, in murine MSN culture dopaminergic agonists prevented a toxic response to Aβ42. Depletion of dopamine in the striatum exacerbated the cognitive impairment seen in a mouse model of early stage AD, which may be due to a protective effect of dopaminergic innervation against Aβ striatal neurotoxicity.

Background: Persons with Barrett's esophagus experience increased risk of esophageal adenocarcinoma. Prediagnostic inflammation markers predict several cancers, but their role in predicting esophageal adenocarcinoma is unknown. Methods: We investigated whether biomarkers of inflammation [C-reactive protein (CRP), interleukin-6 (IL6), soluble tumor necrosis factor (sTNF) receptors I and II], and of oxidative stress (F2-isoprostanes) predicted progression to esophageal adenocarcinoma in a prospective cohort of 397 patients with Barrett's esophagus, 45 of whom developed esophageal adenocarcinoma. Biomarkers were measured in stored plasma samples from two time points during follow-up, the mean of which served as the primary predictor. Adjusted hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox regression. Results: CRP level above the median was associated with an 80% increased risk of esophageal adenocarcinoma. The HR and 95% CI adjusted for age, gender, and further adjusted for waist–hip ratio and smoking were 1.98 (1.05–3.73) and 1.77 (0.93–3.37), respectively, with Ptrend for continuous CRP = 0.04. Persons with IL6 levels above the median also had almost 2-fold increased risk [HR and 95% CI adjusted for age and gender, and further adjusted for waist–hip ratio and smoking were 1.95 (1.03–3.72) and 1.79 (0.93–3.43), respectively, but no evidence of a trend was observed]. Concentrations of TNF receptors and F2-isoprostanes were not associated with esophageal adenocarcinoma risk. Conclusions: Further research is needed to evaluate the role of inflammation and associated markers in esophageal adenocarcinoma development in persons with Barrett's esophagus. Impact: This prospective study suggests that inflammation markers, particularly CRP and IL6, may help identify persons at higher risk of progression to esophageal adenocarcinoma. Cancer Epidemiol Biomarkers Prev; 23(11); 2393–403. ©2014 AACR.

Introduction Labor dystocia (slow or difficult labor or birth) is the most commonly diagnosed aberration of labor and the most frequently documented indication for primary cesarean birth. Yet, dystocia remains a poorly specified diagnostic category, with determinations often varying widely among clinicians. The primary aims of this review are to 1) summarize definitions of active labor and dystocia, as put forth by leading professional obstetric and midwifery organizations in world regions wherein English is the majority language and 2) describe the use of dystocia and related terms in contemporary research studies. Methods Major national midwifery and obstetric organizations from qualifying United Nations-member sovereign nations and international organizations were searched to identify guidelines providing definitions of active labor and dystocia or related terms. Research studies (2000-2013) were systematically identified via PubMed, MEDLINE, and CINAHL searches to describe the use of dystocia and related terms in contemporary scientific publications. Results Only 6 organizational guidelines defined dystocia or related terms. Few research teams (n = 25 publications) defined dystocia-related terms with nonambiguous clinical parameters that can be applied prospectively. There is heterogeneity in the nomenclature used to describe dystocia, and when a similar term is shared between guidelines or research publications, the underlying definition of that term is sometimes inconsistent between documents. Discussion Failure to define dystocia in evidence-based, well-described, clinically meaningful terms that are widely acceptable to and reproducible among clinicians and researchers is concerning at both national and global levels. This failure is particularly problematic in light of the major contribution of this diagnosis to primary cesarean birth rates.

Contemporary labor and birth population norms should be the basis for evaluating labor progression and determining slow progress that may benefit from intervention. The aim of this article is to present guidelines for a common, evidence-based approach for determination of active labor onset and diagnosis of labor dystocia based on a synthesis of existing professional guidelines and relevant contemporary publications. A 3-point approach for diagnosing active labor onset and classifying labor dystocia-related labor aberrations into well-defined, mutually exclusive categories that can be used clinically and validated by researchers is proposed. The approach comprises identification of 1) an objective point that strictly defines active labor onset (point of active labor determination); 2) an objective point that identifies when labor progress becomes atypical, beyond which interventions aimed at correcting labor dystocia may be justified (point of protraction diagnosis); and 3) an objective point that identifies when interventions aimed at correcting labor dystocia, if used, can first be determined to be unsuccessful, beyond which assisted vaginal or cesarean birth may be justified (earliest point of arrest diagnosis). Widespread adoption of a common approach for diagnosing labor dystocia will facilitate consistent evaluation of labor progress, improve communications between clinicians and laboring women, indicate when intervention aimed at speeding labor progress or facilitating birth may be appropriate, and allow for more efficient translation of safe and effective management strategies into clinical practice. Correct application of the diagnosis of labor dystocia may lead to a decrease in the rate of cesarean birth, decreased health care costs, and improved health of childbearing women and neonates.

Mutations in mitochondrial oxidative phosphorylation complex I are associated with multiple pathologies, and complex I has been proposed as a crucial regulator of animal longevity. In yeast, the single-subunit NADH dehydrogenase Ndi1 serves as a non-proton-translocating alternative enzyme that replaces complex I, bringing about the reoxidation of intramitochondrial NADH. We have created transgenic strains of Drosophila that express yeast NDI1 ubiquitously. Mitochondrial extracts from NDI1 -expressing flies displayed a rotenone-insensitive NADH dehydrogenase activity, and functionality of the enzyme in vivo was confirmed by the rescue of lethality resulting from RNAi knockdown of complex I. NDI1 expression increased median, mean, and maximum lifespan independently of dietary restriction, and with no change in sirtuin activity. NDI1 expression mitigated the aging associated decline in respiratory capacity and the accompanying increase in mitochondrial reactive oxygen species production, and resulted in decreased accumulation of markers of oxidative damage in aged flies. Our results support a central role of mitochondrial oxidative phosphorylation complex I in influencing longevity via oxidative stress, independently of pathways connected to nutrition and growth signaling.

Certified nurse-midwives are teaching obstetrics and gynecology residents and medical students in major academic institutions across the United States. In these instances, the ability to appropriately document services rendered to support a billable service is paramount. This article explains the difference in requirements for midwives' documentation when working with residents compared with documentation required of an attending obstetrician-gynecologist. It also reviews the teaching physician guidelines developed by the Centers for Medicare and Medicaid Services (CMS) as well as current evaluation and management documentation requirements. Several examples of documentation are provided, as are suggestions for enhancement and simplification of the guidelines to include midwives. An important point to remember is that the CMS rules do not prohibit a certified nurse-midwife from teaching a resident.

Objective: Since attention-deficit/hyperactivity disorder (ADHD) is a well-documented risk factor for smoking and bupropion has been shown to be effective for smoking cessation, we tested the efficacy of bupropion as a prophylactic agent for the prevention of smoking in children and adolescents with ADHD. Method: We conducted a longitudinal, randomized, double-blind, placebo-controlled, parallel-group study of bupropion at a large, urban, outpatient medical center. Recruitment began in April 1999, and the last subject was followed until September 2004. Patients were nonsmoking youth, of both sexes, between 9 and 18 years of age, with DSM-IV ADHD. After random assignment to either bupropion or placebo, subjects were assessed weekly for 8 weeks, biweekly for 4 weeks, and monthly thereafter for up to 6.5 years (mean 12 months). Also, patients received treatment with psychostimulants for ADHD symptoms as needed. To assess smoking, we used an assay of cotinine in urine. Results: Fifty-seven subjects (28 receiving bupropion and 29 receiving placebo) were randomly assigned and included in the analysis. No differences were found between the bupropion and placebo groups on demographic factors. About half of each group was treated with stimulants for ADHD. Statistical separation between bupropion and placebo in the rate of smoking initiation or continued smoking was not demonstrated. However, secondary post hoc analyses revealed that concurrent stimulant treatment was significantly associated with a lower rate of smoking onset (hazard ratio [HR] = 0.2, 95% CI = 0.08 to 0.89; z = -2.2, p = .03) and a lower rate of continued smoking (HR = 0.3, 95% CI = 0.11 to 0.85; z = -2.3, p = .02). Conclusion: While bupropion was not associated with a lower rate of smoking in youth with ADHD, post hoc analyses suggest that stimulant treatment was. Future controlled studies should investigate the role of stimulants in the prevention of smoking in children and adolescents with ADHD.

Human cerebrospinal fluid (CSF) contains diverse lipid particles, including lipoproteins that are distinct from their plasma counterparts and contain apolipoprotein (apo) E isoforms, apoJ, and apoAI, and extracellular vesicles, which can be detected by annexin V binding. The aim of this study was to develop a method to quantify CSF particles and evaluate their relationship to aging and neurodegenerative diseases. We used a flow cytometric assay to detect annexin V-, apoE-, apoAI-, apoJ-, and amyloid (A) β42-positive particles in CSF from 131 research volunteers who were neurologically normal or had mild cognitive impairment (MCI), Alzheimer disease (AD) dementia, or Parkinson disease. APOE e4/e4 participants had CSF apoE-positive particles that were more frequently larger but at an 88% lower level versus those in APOE e3/e3 or APOE e3/e4 patients; this finding was reproduced in conditioned medium from mouse primary glial cell cultures with targeted replacement of apoE. Cerebrospinal fluid apoE-positive and β-amyloid (Aβ42)-positive particle concentrations were persistently reduced one-third to one-half in middle and older age subjects; apoAI-positive particle concentration progressively increased approximately 2-fold with age. Both apoAI-positive and annexin V-positive CSF particle levels were reduced one-third to one-half in CSF of MCI and/or AD dementia patients versus age-matched controls. Our approach provides new methods to investigate CNS lipid biology in relation to neurodegeneration and perhaps develop new biomarkers for diagnosis or treatment monitoring.

P450 2E1 is an important mammalian liver enzyme known to metabolize a wide range of compounds including several common environmental pollutants. The medicinal plant, Atropa belladonna, was transformed with Agrobacterium rhizogenes containing a binary vector with rabbit P450 2E1 in either the sense or antisense orientation. The resulting "hairy roots" were isolated and grown in liquid medium. Production of P450 2E1 protein was verified in the roots containing the 2E1 gene in the sense orientation. Transgenic and control root cultures were dosed with the environmental pollutant, trichloroethylene (TCE), and were analyzed for the TCE metabolites, chloral and trichloroethanol. The root cultures expressing the mammalian P450 2E1 had increased levels of the metabolites compared to the levels in the control roots. This method represents a quick way to screen transformants for expression of foreign genes before regeneration of whole plants, and also as a possible source of foreign protein for purification.

MICROPARTICLES IN HUMAN CEREBROSPINAL FLUID OF NEURODEGENERATIVE DISORDERS Yue Yang, Elaine R. Peskind, Eiron Cudaback, Angela M. Wilson, Thomas J. Montine, C. Dirk Keene, University of Washington, Seattle, Washington, United States; VA Puget Sound Health Care System, Seattle, Washington, United States; 3 University of Washington, Seattle, Washington, United States; 4 University of Washington, Seattle, Washington, United States; University of Washington, Seattle, Washington, United States. Contact e-mail: yangyue@uw.edu

Trichloroethylene (TCE) is a widespread and persistent environmental contaminant. Recently, plants, poplar trees in particular, have been investigated as a tool to remove TCE from soil and groundwater. The metabolism of TCE in plants is being investigated for two reasons: one, plant uptake and metabolism represent an important aspect of the environmental fate of the contaminant; two, metabolism pattern and metabolite identification will help assess the applicability of phytoremediation. It was previously shown that TCE metabolites in plants are similar to ones that result from cytochrome P450-mediated oxidation in mammals: trichloroethanol, trichloroacetate and dichloroacetate. Our measurements indicate that one of these metabolites, trichloroethanol, is further glycosylated in tobacco and poplar. The glycoside was detected in all tissues (roots, stems and leaves) in comparable levels, and was at least 10 fold more abundant than free trichloroethanol. The glycoside in tobacco was identified as the ss-D-glucoside of trichloroethanol by comparison of the mass spectra and the chromatographic retention time of its acetylation product to that of the synthesized standard. Trichloroethanol and its glucoside did not persist in plant tissue once plants are removed from TCE contaminated water, indicating further metabolism.

Chlorinated solvents, especially trichloroethylene (TCE), are the most widespread groundwater contaminants in the United States. Existing methods of pumping and treating are expensive and laborious. Phytoremediation, the use of plants for remediation of soil and groundwater pollution, is less expensive and has low maintenance; however, it requires large land areas and there are a limited number of suitable plants that are known to combine adaptation to a particular environment with efficient metabolism of the contaminant. In this work, we have engineered plants with a profound increase in metabolism of the most common contaminant, TCE, by introducing the mammalian cytochrome P450 2E1. This enzyme oxidizes a wide range of important pollutants, including TCE, ethylene dibromide, carbon tetrachloride, chloroform, and vinyl chloride. The transgenic plants had a dramatic enhancement in metabolism of TCE of up to 640-fold as compared with null vector control plants. The transgenic plants also showed an increased uptake and debromination of ethylene dibromide. Therefore, transgenic plants with this enzyme could be used for more efficient remediation of many sites contaminated with halogenated hydrocarbons.

As overwhelmingly positive results have become available regarding the ability of plants to degrade compounds such as trichloroethylene, phytoremediation studies are expanding. Studies to determine the potential for phytoremediation of fully chlorinated compounds, such as carbon tetrachloride and tetrachloroethylene, brominated compounds, such as ethylene dibromide and dibromochloropropane, and nonhalogenated compounds, such as methyl-t-butyl ether (MTBE), are underway. When using phytoremediation, it is important to select not only a plant that is capable of degrading the pollutant in question, but also one that will grow well in that specific environment. In ecologically sensitive areas, such as the Hawaiian Islands, only plants native to the area can be used. One way to supplement the arsenal of plants available for remedial actions is to utilize genetic engineering tools to insert into plants those genes that will enable the plant to metabolize a particular pollutant. Hybrid technologies, such as usin...

Alzheimer's disease (AD) is a common age-related chronic illness with latent, prodrome, and fully symptomatic dementia stages. Increased free radical injury to regions of brain is one feature of prodrome and dementia stages of AD; however, it also is associated with advancing age. This raises the possibility that age-related free radical injury to brain might be caused in part or in full by latent AD. We quantified free radical injury in the central nervous system with cerebrospinal fluid (CSF) F(2)-isoprostanes (IsoPs) in 421 clinically normal individuals and observed a significant increase over the adult human lifespan (P 0.001). Using CSF amyloid (A) β(42) and tau, we defined normality using results from 28 clinically normal individuals 50 years old, and then stratified 74 clinically normal subjects ≥60 years into those with CSF that had normal CSF Aβ(42) and tau (n = 37); abnormal CSF Aβ(42) and tau, the biomarker signature of AD (n = 24); decreased Aβ(42) only (n = 4); or increased tau only (n = 9). Increased CSF F(2)-IsoPs were present in clinically normal subjects with the biomarker signature of AD (P 0.05) and those subjects with increased CSF tau (P 0.001). Finally, we analyzed the relationship between age and CSF F(2)-IsoPs for those clinically normal adults with normal CSF (n = 37) and those with abnormal CSF Aβ(42) and/or tau (n = 37); only those with normal CSF demonstrated a significant increase with age (P 0.01). These results show that CSF F(2)-IsoPs increased across the human lifespan and that this age-related increase in free radical injury to brain persisted after culling those with laboratory evidence of latent AD.

In nonalcoholic fatty liver disease (NAFLD), depletion of hepatic antioxidants may contribute to the progression of steatosis to nonalcoholic steatohepatitis (NASH) by increasing oxidative stress that produces lipid peroxidation, inflammation, and fibrosis. We investigated whether depletion of glutathione (GSH) increases NASH-associated hepatic pathology in mice fed a diet deficient in methionine and choline (MCD diet). Wild-type (wt) mice and genetically GSH-deficient mice lacking the modifier subunit of glutamate cysteine ligase (Gclm null mice), the rate-limiting enzyme for de novo synthesis of GSH, were fed the MCD diet, a methionine/choline-sufficient diet, or standard chow for 21 days. We assessed NASH-associated hepatic pathology, including steatosis, fibrosis, inflammation, and hepatocyte ballooning, and used the NAFLD Scoring System to evaluate the extent of changes. We measured triglyceride levels, determined the level of lipid peroxidation products, and measured by qPCR the expression of mRNAs for several proteins associated with lipid metabolism, oxidative stress, and fibrosis. MCD-fed GSH-deficient Gclm null mice were to a large extent protected from MCD diet-induced excessive fat accumulation, hepatocyte injury, inflammation, and fibrosis. Compared with wt animals, MCD-fed Gclm null mice had much lower levels of F2-isoprostanes, lower expression of acyl-CoA oxidase, carnitine palmitoyltransferase 1a, uncoupling protein-2, stearoyl-coenzyme A desaturase-1, transforming growth factor-β, and plas-minogen activator inhibitor-1 mRNAs, and higher activity of catalase, indicative of low oxidative stress, inhibition of triglyceride synthesis, and lower expression of profibrotic proteins. Global gene analysis of hepatic RNA showed that compared with wt mice, the livers of Gclm null mice have a high capacity to metabolize endogenous and exogenous compounds, have lower levels of lipogenic proteins, and increased antioxidant activity. Thus, metabolic adaptations resulting from severe GSH deficiency seem to protect against the development of steatohepatitis.

Ethylene dibromide (EDB; dibromoethane) and trichloroethylene (TCE) are hazardous environmental pollutants. The use of plants to treat polluted sites and groundwater, termed phytoremediation, requires plants that can both effectively remove the pollutant as well as grow in the climatic region of the site. In this paper, we report that the tropical leguminous tree, Leuceana leucocephala var. K636, is able to take up and metabolize EDB and TCE. The plants were grown in sterile hydroponic solution without its symbiont, Rhizobium. EDB and TCE were both metabolized by the plant, as indicated by the formation of bromide ion from EDB and trichloroethanol from TCE. Each plant organ was independently capable of debromination of EDB. L. leucocephala is being used to treat perched groundwater as part of a remedial alternative to address an accidental EDB spill in Hawaii. Bromide levels of plant tissues from the trees grown in the phytoremediation treatment cells at the Hawaii Site were elevated, indicating uptake and degradation of brominated compounds in the trees. This report is the first evidence of a tropical tree effectively metabolizing these common organic pollutants.

The mechanisms regulating retrograde neuronal degeneration and subsequent death of thalamic neurons following cortical injury are not well understood. However, the delay in the onset of retrograde cell death and observed morphological changes are consistent with apoptosis. Our previous studies demonstrated that monocyte chemoattractant protein-1 (MCP-1), a β-chemokine that attracts cells of monocytic origin to sites of injury, is rapidly and specifically expressed in the lateral geniculate nucleus following visual cortical lesions. To determine the potential role of MCP-1 in retrograde degeneration, the present study examined the effect of genetic deletion of MCP-1 (MCP-1 KO or −/−) or its high affinity receptor CCR2 (CCR2 KO or −/−) on thalamic microglial activation and neuronal cell death following aspiration lesions of the visual cortex in adult mice. Deletion of the MCP-1 gene delayed microglial activation and transiently improved the survival of thalamic neurons. Deletion of the CCR2 receptor resulted in a significant increase in apoptosis as measured by nucleosomal fragmentation after injury compared to wild-type mice, but did not alter neuron survival, suggesting that glial apoptosis is increased in the receptor knockout mice. Investigation of Bcl-2, Bax, Fas, Fas ligand (FasL) and activated caspase-3, key regulators of apoptosis that can be modulated by cytokines, revealed complex alterations of mRNA and protein levels in MCP-1 −/− and CCR2 −/− mice. As examples, Bcl-2 protein was detected in wild-type, but not in MCP-1 −/− mice. Caspase-3 activity was higher in MCP-1 −/− mice compared to wild-type and CCR2 −/− mice at 5 days after injury. High levels of activated caspase-3 correlate with the beginning of a period of delayed, but rapid cell death in the thalami of MCP-1 −/− mice. In summary, our data strongly suggest that MCP-1 is involved in early microglial response to axotomy and that modulation of this chemokine could provide a novel strategy for improved neuronal survival following injury to the central nervous system.

The ACI rat is extremely sensitive to estrogens as mammary carcinogens, whereas the Sprague-Dawley strain is relatively resistant. Comparison of the disposition and effects of estrogens in these two strains should provide insights into the mechanisms of estrogen carcinogenicity. We have begun this investigation by comparing the metabolism of [(3)H]17beta-estradiol (E2) by liver microsomes prepared from female rats from each strain. Both strains produce estrone (E1) as the major product at E2 concentrations >1 microM, with smaller amounts of 2-hydroxy-E2 formed. As the E2 concentration is decreased, however, aromatic hydroxylation becomes a more dominant pathway for both strains. At starting E2 concentrations as low as 3 nM, Sprague-Dawley liver microsomes produced comparable yields of 2-hydroxy-E2 and E1. In contrast, ACI liver microsomes yielded a profound shift to aromatic hydroxylation as the dominant pathway as E2 concentrations dropped below 1 microM, and this shift reflected the production of 4-hydroxy-E2 as the predominant product. The apparent K(m) for 4-hydroxylation of E2 is

Rat strains are known to differ markedly in their susceptibility to estrogen (E)-induced mammary tumors. Specifically, the ACI strain is extremely sensitive to Es, whereas the Sprague- Dawley (SD) strain is relatively resistant. We have compared the metabolism of estradiol (E2) by liver microsomes from these two rat strains. Both strains exhibit hydroxysteroid dehydrogenase activity, with estrone (E1) being the major product at E2 concentrations above 1 μM. Some A-ring hydroxylation also is seen. As the E2 concentration is decreased, however, hydroxylation becomes a more dominant pathway for both strains. In the SD preparations this still yields E1 as the major product. ACI liver, however, produces primarily hydroxylated-E2 at these concentrations. This difference is most apparent at E2 concentrations below 100 nM. This difference in the disposition of E2 and its being most pronounced at E2 concentrations nearing the physiological range, suggest that this difference may contribute to the relative sensitivity of these strains to E2 carcinogenicity.

SUMMARY Accumulations of neutral fat were found, especially in the grey matter, in the brains of all of 18 mice affected with scrapie; their nature and distribution were fundamentally different from lesions previously reported. Certain areas of the brain were consistently affected, particularly the caudal region o f the hippocampus, the anterior group of thalamic nuclei, the substantia nigra and the molecular layer of the cerebellar cortex. The fatty lesions, in common with other changes in scrapie, showed pronounced bilateral symmetry. They were not apparently accompanied by any specific cellular or tissue response in the same foci and were not shown to be dependent on myelin degeneration. Fifteen control mice not affected with scrapie did not contain fat in the areas considered to be predilection sites in affected animals.

The progressive histopathology and histochemical changes in mice infected experimentally with an avirulent strain (A774) of Semliki forest virus were compared with reactions caused by a virulent strain (L10) of the same virus and with results in previous work on scrapie, cuprizone-induced encephalopahyy and viral encephalitides. Apart from cellular degeneration and infiltration, the avirulent strain of virus was characterized pathologically by focal spongiform lesions that had an irregular distribution in brain and spinal cord. These focal lesions incorporated peripheral astrocytic hypertrophy and were associated with intense activity of glycoside hydrolases, especially N-acetyl-β- d -glucosaminidase which corroborated previous biochemical results and in addition elucidated the location of enzyme changes. The nature of the lesions and their pathogenesis suggested that infection by avirulent (A774) Semliki forest virus merits a pathological classification intermediate between acute inflammatory-type encephalitis and the scrapiecuprizone type of spongiform encephalopathy.

Histochemical tests for two glycoside hydrolases, β-glucuronidase (GUR) and N-acetyl-β-D-glucosaminidase (GAM) were carried out on sections of brain and other tissues from mice experimentally infected with scrapie and from control mice. Increased activity of both enzymes was detected in the central nervous system of mice affected with scrapie, compared with low levels in normal mice. Neither enzyme was significantly altered in other tissues. Scrapie-inoculated mice in one series were killed at intervals between 30 and 120 days after inoculation and the development of increasing GAM activity in brain sections was followed. Abnormal activity was first detected 58 days after inoculation i.e. about 6 weeks before the onset of the clinical phase, and progressively increased to very strong positive reactions, easily discernible macroscopically, in the clinical phase. The location and distribution of abnormal enzyme activity followed consistent, although differing, patterns with both enzymes. Comparable tests in scrapie-affected and normal rats, sheep and goats showed that increased GAM activity could be detected in the rat, but not in the sheep or goat. The location of normal GUR in sheep and goats was different from that in mice and rats, being predominatly found in large neurones as well as paravascular. Both in scrapie sheep and in scrapie goats there was a qualitative difference in intraneuronal GUR, manifested as cells containing GUR droplets. Ways in which this histochemical dimension may add to fundamental concepts of the disease process and correlate with other facets of scrapie pathology are discussed.