Impacts of the Ban on the Soil-Applied Fumigant Methyl Bromide

The loss of the soil fumigant methyl bromide (MeBr) and adoption of soil fumigant alternatives has been challenging for farmers, particularly for those crops in which pathogens previously controlled by MeBr have emerged as significant problems, but it has resulted in some unanticipated benefits for the scientific community and the environment. Applauded as one of the most effective environmental agreements to date, the universally accepted Montreal Protocol on Ozone Depleting Substances has had a significant impact on the environment, reducing the release of halogenated compounds from anthropogenic sources enough to mitigate global warming by an estimated 1.1°C by 2021. The funding associated with various MeBr transition programs has increased collaboration across scientific disciplines, commodity groups, industry, and regulatory agencies. Chemical alternatives and improved application strategies, including the development of gas-retentive agricultural films, coupled with sound efficacy data and grower ingenuity have resulted in the sustained production of many of the impacted crops; although there has been some loss of acreage and value, particularly for Florida fumigated crops, but for some, value has continued to increase, allowing production to continue. The loss of a single, broad-spectrum tool for pest control has led to a deeper understanding of the specific pest complexes impacting these at-risk crops, as well as the development of new, biologically based management tools for their control, while increasing our understanding of the role of the soil microbiome in pest control and crop production.

Feasibility and acceptability in health centers of screening for chlamydia in deprived population

Issue

The French Health Insurance (FHI) is in charge of the governance of 100 Health Examination Centers (HEC). HEC provide evidence-based interventions in prevention, focused on deprived population. In France, Chlamydia trachomatis (Ct) infection is the most sexually transmitted infection, especially among young women.

Description of the problem

To assess the feasibility of systematic screening Ct infection, in HEC, among 18-25 years women and 18-30 years men, with a focus on self-sampling. Pragmatics questions were: how the youth accept the screening of Ct infection (especially the self-taken vaginal swabs)? Was the feasibility and Ct positivity similar between deprived and non-deprived population (according to the EPICES score)? A cross-sectional multicenter survey was performed in 13 HEC in January 2018.

Results

Screening was proposed to 1702 eligible young people (sexually active and no recent Ct treatment). 90.3% [88.8-91.6] accepted and participated: 44% women, 54% deprived people. Among women, 76.8% [73.4-79.9] used self-taken vaginal swabs, others urinary tests. Rates did not differ according to deprivation (p = 0.96). Screening was performed in 1487 people (96.7% for deprived vs 97.7% for non-deprived population, p = 0.258). Ct detection rate was 4.7% [3.7%-5.9%], significantly higher for deprived population (6.5% vs 2.5%, p < 0.001).

Lessons

The results demonstrated the feasibility of Ct screening in HEC with a good acceptance among youth even among young deprived. The performance rate of the test was similar according to deprivation. However, deprivation was associated with having a positive Ct result. This feasibility led to the implementation of Ct screening in all HEC.

Key messages

Chlamydia trachomatis screening can be easily implemented even in deprived populations that accept and perform it as well as non-deprived populations. Promoting access to Chlamydia trachomatis screening to deprived populations might contribute to reduce social inequalities in health.

Study protocol for a pragmatic randomised controlled trial evaluating efficacy of a smoking cessation e-'Tabac Info Service': ee-TIS trial

INTRODUCTION

A French national smoking cessation service, Tabac Info Service, has been developed to provide an adapted quitline and a web and mobile application involving personalised contacts (eg, questionnaires, advice, activities, messages) to support smoking cessation. This paper presents the study protocol of the evaluation of the application (e-intervention Tabac Info Service (e-TIS)). The primary objective is to assess the efficacy of e-TIS. The secondary objectives are to (1) describe efficacy variations with regard to users' characteristics, (2) analyse mechanisms and contextual conditions of e-TIS efficacy.

METHODS AND ANALYSES

The study design is a two-arm pragmatic randomised controlled trial including a process evaluation with at least 3000 participants randomised to the intervention or to the control arm (current practices). Inclusion criteria are: aged 18 years or over, current smoker, having completed the online consent forms, possessing a mobile phone with android or apple systems and using mobile applications, wanting to stop smoking sooner or later. The primary outcome is the point prevalence abstinence of 7 days at 6 months later. Data will be analysed in intention to treat (primary) and per protocol analyses. A logistic regression will be carried out to estimate an OR (95% CI) for efficacy. A multivariate multilevel analysis will explore the influence on results of patients' characteristics (sex, age, education and socioprofessional levels, dependency, motivation, quit experiences) and contextual factors, conditions of use, behaviour change techniques.

ETHICS AND DISSEMINATION

The study protocol was reviewed by the ethical and deontological institutional review board of the French Institute for Public Health Surveillance on 18 April 2016. The findings of this study will allow us to characterise the efficacy of e-TIS and conditions of its efficacy. These findings will be disseminated through peer-reviewed articles.

TRIAL REGISTRATION NUMBER

NCT02841683; Pre-results.

[How to develop health education within general medicine and pharmaceutical practice? Implementation methods used in an experiment with pregnant women, adolescents and elderly people]

Through the impetus of the National Institute of Prevention and Health Education (INPES) and the National Funding Agency for Social Security (CNAMTS), five different health education interventions were designed and implemented by 61 general practitioners and pharmacists in 5 pilot locations in France. The projects involved 185 senior citizens, adolescents and pregnant women. The strategic development of these projects required training the participating health professionals for a period of one year within the framework of a structured programme. The educational interventions were subsequently designed to specifically meet health education criteria and standards, namely, incorporating a broad as well as individualised approach to the patient and including active participation in the learning process. The programme elements are not oriented towards a thematic approach, nor around a specific health topic, but rather they focus on the individual as belonging to part of a given population group. It is therefore a population oriented health education approach.

Use of antibiotics in hospitals in south-western France

Data on the use of antibiotics were collected by means of a questionnaire from 49 hospitals in south-western France. Use was expressed as a usage density rate: number of defined daily doses (DDDs) per 1000 patient-days. The average use of antibiotics amounted to 402 DDDs per 1000 patient-days and varied between 60 and 734. In acute-care wards, the amount of antibiotic use increased with the size of the hospital: 461 DDDs per 1000 patient-days for group A (<100 beds), 510 DDDs per 1000 patient-days for group B (more than 100 and less then 300 beds) and 676 DDDs per 1000 patient-days for group C (>300 beds). The rate of use differed among different types of hospital areas and varied from 58 for psychiatry departments to more than 1273 DDDs per 1000 patient-days for the infectious diseases departments. Broad-spectrum penicillins were the most frequently prescribed antibiotics. Fluoroquinolone and third-generation cephalosporin use were relatively uniform in the three size categories. This study shows that it is possible for a hospital to benchmark its consumption with other hospitals that are similar in size. In this way, surveillance of antibiotic use can aid hospitals in targeting infection control efforts.

Single-dose pharmacokinetics of amprenavir coadministered with grapefruit juice

In this crossover study in 12 healthy volunteers, coadministration of amprenavir (1,200 mg; single dose) with grapefruit juice slightly reduced the maximum concentration of drug in serum (Cmax) compared to administration with water (7.11 versus 9.10 microg/ml), slightly increased the time to Cmax (1.13 versus 0.75 h), and did not affect the area under the concentration-time curve from 0 to 12 h (AUC(0-12)), the AUC(0-infinity), or the concentration at 12 h. Therefore, grapefruit juice does not clinically significantly affect amprenavir pharmacokinetics.

Hyperphosphorylation of RNA polymerase II and reduced neuronal RNA levels precede neurofibrillary tangles in Alzheimer disease

Affected neurons of Alzheimer disease (AD) brain are distinguished by the presence of the cell cycle cdc2 kinase and mitotic phosphoepitopes. A significant body of previous data has documented a decrease in neuronal RNA levels and nucleolar volume in AD brain. Here we present evidence that integrates these seemingly distinct findings and offers an explanation for the degenerative outcome of the disease. During mitosis cdc2 phosphorylates and inhibits the major transcriptional regulator RNA polymerase II (RNAP II). We therefore investigated cdc2 phosphorylation of RNAP II in AD brain. Using the H5 and H14 monoclonal antibodies specific for the cdc2-phosphorylated sites in RNAP II, we found that the polymerase is highly phosphorylated in AD. Moreover, RNAP II in AD translocates from its normally nuclear compartment to the cytoplasm of affected neurons, where it colocalizes with cdc2. These M phase-like changes in RNAP II correlate with decreased levels of poly-A RNA in affected neurons. Significantly, they precede tau phosphorylation and neurofibrillary tangle formation. Our data support the hypothesis that inappropriate activation of the cell cycle cdc2 kinase in differentiated neurons contributes to neuronal dysfunction and degeneration in part by inhibiting RNAP II and cellular processes dependent on transcription.

Constitutive Cdc25B tyrosine phosphatase activity in adult brain neurons with M phase-type alterations in Alzheimer's disease

The Cdc2/cyclin B kinase is a critical regulator of mitosis that is normally absent from terminally differentiated neurons of adult brain. However, unscheduled expression and activation of Cdc2/cyclin B has been seen in neurons undergoing degeneration in Alzheimer's disease. The presence of this mitotic kinase correlates with accumulation of mitotic phosphoepitopes in protein components of the hallmark neurofibrillary tangles. Of importance to the pathogenic mechanism of Alzheimer's disease is the striking appearance of Cdc2/cyclin B and mitotic phosphoepitopes prior to neurofibrillary tangle formation, which has suggested that a misappropriate mitotic cascade initiates and mediates the neurodegenerative process. To explain the atypical activation of Cdc2/cyclin B in degenerating neurons we have investigated the enzyme responsible for Cdc2/cyclin B activation in mitotic cells, i.e. the Cdc25B tyrosine phosphatase, in Alzheimer's disease brain. Although the enzyme appeared abundant in affected neurons, it was also evident in unaffected neurons of Alzheimer's disease and control brain. Thus, we have found, surprisingly, that Cdc25B is a normal constituent of adult brain neurons, with detectable basal levels of activity. In Alzheimer's disease the levels and activity of the enzyme are elevated, and the active enzyme predominates in the cytoplasmic compartment of neurons. Consistent with these M phase-type changes, Cdc25B displays increased immunoreactivity towards the MPM-2 mitotic phosphoepitope antibody. We propose that aberrant expression of Cdc2/cyclin B in Alzheimer's disease leads to potentiation of mitotic activation mediated by constitutive neuronal Cdc25B activity. As a result, various downstream indices of mitotic events are generated, eventually culminating in neurodegeneration. Our data also suggest that Cdc25B is functional in normal post-mitotic neurons lacking the mitotic Cdc2/cyclin B, but it does not appear to influence the activity of Cdk5, a Cdc2-like kinase that is particularly enriched in brain.

Cdc2 phosphorylation of nucleolin demarcates mitotic stages and Alzheimer's disease pathology

Nucleolin is a major multifunctional nuclear phosphoprotein that is phosphorylated by Cdc2 kinase in mitosis and that participates in a number of cellular processes. The monoclonal antibody TG-3 generated against neurofibrillary tangles (NFT) found in Alzheimer's disease (AD) is highly specific for mitotic cells in culture. We here demonstrate that phosphorylation of nucleolin by Cdc2 kinase generates the TG-3 epitope. The unique pool of TG-3 immunoreactive nucleolin appears abruptly during the prophase. It is associated with chromosomes through the metaphase and it gradually disappears during separation of chromosomes and exit from mitosis. In the brain, nucleolin was localized not only to nuclei but also to neuronal cytoplasm, and it is a marker for early NFT. In patients with AD, Cdc2 phosphorylated nucleolin was present in NFT. These findings suggest that phosphorylation of nucleolin by Cdc2 kinase is a critical event and the point of convergence of two distinct pathways, mitosis and neurodegeneration.

The cell cycle Cdc25A tyrosine phosphatase is activated in degenerating postmitotic neurons in Alzheimer's disease

The Cdc25 phosphatases play key roles in cell-cycle progression by activating cyclin-dependent kinases. The latter are absent from neurons that are terminally differentiated in adult brain. However, accumulation of mitotic phosphoepitopes, and re-expression and activation of the M phase regulator, Cdc2/cyclin B, have been described in neurons undergoing degeneration in Alzheimer's disease (AD). To explain this atypical mitotic activation in neurons we investigated the Cdc2-activating Cdc25A phosphatase in human brain. The structural hallmarks of AD neurodegeneration, neurofibrillary tangles and neuritic plaques, were prominently immunolabeled with Cdc25A antibodies. In addition numerous neurons without visible structural alterations were also intensely stained, whereas control brain was very weakly positive. After immunoprecipitation from control and AD tissue, we found that the tyrosine dephosphorylating activity of Cdc25A against exogenous Cdc2 substrate was elevated in AD. Accordingly, Cdc25A from AD tissue displayed increased immunoreactivity with the mitotic phosphoepitope-specific antibody, MPM-2, and co-localized with MPM-2 immunoreactivity in AD neurons. These data suggest that Cdc25A participates in mitotic activation during neurodegeneration. The involvement of Cdc25A in cellular transformation, modulation of the DNA damage checkpoint, and linkage of mitogenic signaling to cell cycle machinery, also implicates one of these cell-cycle pathways in AD pathogenesis.

Mitotic activation: a convergent mechanism for a cohort of neurodegenerative diseases

Previous evidence from our lab and others has implicated the mitotic cdc2/cyclin B1 kinase in the neurofibrillary degeneration of Alzheimer's disease. To examine the specificity of this relationship, and define conditions leading to atypical activation of mitotic kinase in postmitotic neurons, we have applied antibodies specific for the cdc2 kinase, its activator, cyclin B1, and three cdc2 produced phosphoepitopes: the TG-3 phosphoepitope in tau and nucleolin, the MPM-2 phosphoepitope in a variety of substrates, and the H5 phosphoepitope in RNA polymerase II, to affected brain regions from a spectrum of neurodegenerative disorders. Our results demonstrate that neurons containing characteristic lesions in a subset of diseases including Down Syndrome (DS), Frontotemporal Dementia linked to chromosome 17 (FTD-17), Progressive Supranuclear Palsy (PSP), Corticobasal Degeneration (CBD), Parkinson-Amyotrophic Lateral Sclerosis of Guam (GP-ALS), Niemann Pick disease type C (NPDC), and Pick's disease, display mitotic indices, implicating diverse etiologies in mitotic activation. The convergence of various degenerative schemes into a unified mitotic kinase-driven pathway provides a common target for therapeutic treatment of these different disorders.

Modalities of palliative care in hospitalized patients with advanced AIDS

This prospective multidisciplinary survey started in October 1994. The survey assessed the modalities of care of hospitalized patients with advanced AIDS in an Infectious and Tropical Diseases Unit with regards to the practices of palliative care in a Palliative Care Unit. Seventy-eight (78) AIDS patients with CD4 < or = 30/mm3 who had 102 consecutive hospitalizations were recruited. Types (symptomatic or curative) and number of drugs administered to the patients, as well as biological and radiological investigations performed were recorded. Symptoms were concomitantly assessed on a weekly basis by self-evaluation of the patients themselves and by physicians. The results showed that the practices of care were different in the two units according to the specific goals and norms of each unit. A higher density of care was delivered at the Infectious and Tropical Diseases Unit. Symptoms assessed by both patients and physicians were underestimated by physicians in frequency and in intensity. In conclusion, an integrated approach including objective and subjective criteria should enable a better adjustment of the palliative and curative therapeutic strategies in advanced AIDS. These would concomitantly take into account the wishes of the patient and the goals regarding care in the unit where the patient is hospitalized.

High-throughput assay for G2 checkpoint inhibitors and identification of the structurally novel compound isogranulatimide

Treatment of cancer cells lacking p53 function with G2 checkpoint inhibitors sensitizes them to the toxic effects of DNA damage and has been proposed as a strategy for cancer therapy. However, few inhibitors are known, and they have been found serendipitously. We report the development of a G2 checkpoint inhibition assay that is suitable for high-throughput screening and its application to a screen of 1300 natural extracts. We present the isolation of a new G2 checkpoint inhibitor, the structurally novel compound isogranulatimide. In combination with gamma-irradiation, isogranulatimide selectively kills MCF-7 cells lacking p53 function.

Mitotic phosphoepitopes precede paired helical filaments in Alzheimer's disease

We have shown previously that the TG-3 and MPM-2 antibodies recognize phosphoepitopes common to mitosis and degenerating neurons of Alzheimer's disease(AD) brain. Here, we have evaluated their occurrence in human brain biopsy tissue, and confirm that they are absent in mature neurons of adult brain, but reappear during neurodegeneration in AD. The TG-3 epitope appears ahead of the MPM-2 epitope and is distributed throughout the neuronal soma. Tau is the major TG-3 antigen in AD brain. The initial localization of MPM-2 immunoreactivity in primary dendrites, it's robust occurrence in granulovacuolar bodies, and the increased immunoreactivity with 300-350-kDa proteins, suggest MAPI B as a candidate MPM-2 antigen in AD. Production of mitotic phosphepitopes in more than one type of human neurodegenerative lesion implicates mitotic kinases as common mediators of neuronal death. Because mitotic phosphoepitopes appear before paired helical filaments, it is suggested that mitotic kinase activation triggers neurofibrillary tangle formation. Future studies will need to focus on factors influencing mitotic kinase activity, a point with potential for early diagnosis and disease abrogation.

Flow cytometry of mitotic cells

We have developed a procedure using flow cytometric measurement of a mitosis-specific antigen that may be used to count mitotic cells and sort them from non-mitotic cells. The procedure may also be used in conjunction with measurement of cellular DNA content and of bromodeoxyuridine incorporation into cellular DNA to assign cells to the G1/G0, S, G2, or M phase of the cell cycle.

A conformation- and phosphorylation-dependent antibody recognizing the paired helical filaments of Alzheimer's disease

Hyperphosphorylated tau (PHF-tau) is the major constituent of paired helical filaments (PHFs) from Alzheimer's disease (AD) brains. This conclusion has been based largely on the creation and characterization of monoclonal antibodies raised against PHFs, which can be classified in three categories: (a) those recognizing unmodified primary sequences of tau, (b) those recognizing phosphorylation-dependent epitopes on tau, and (c) those recognizing conformation-dependent epitopes on tau. Recent studies have suggested that the antibodies recognizing primary sequence and phosphorylation-dependent epitopes on tau are unable to distinguish between normal adult biopsy tau and PHF-tau. We now present evidence for a new fourth class of monoclonal antibodies recognizing conformation-dependent phosphoepitopes on tau, typified by TG-3, a monoclonal antibody raised to PHFs from AD brain homogenates. Studies using a series of deletional tau mutants, site-directed tau mutants, and synthetic peptides enable the precise epitope mapping of TG-3. Additional studies demonstrate that TG-3 reacts with neonatal mouse tau and PHF-tau but does not recognize adult mouse tau or tau derived from normal human autopsy or biopsy tissue. Further investigation reveals that TG-3 recognizes a unique conformation of tau found almost exclusively in PHFs from AD brains.

Aberrant expression of mitotic cdc2/cyclin B1 kinase in degenerating neurons of Alzheimer's disease brain

We have shown previously that M-phase phospho-epitopes accumulate in neuronal tau proteins incorporated into the hallmark neurofibrillary tangles (NFT) of Alzheimer's disease (AD). In M phase, the epitopes are produced by cdc2/cyclin B1 kinase by a highly conserved mechanism believed to be quiescent in terminally differentiated neurons of adult brain. To determine whether an M-phase mechanism is possible in AD neurons, we first investigated the presence of cdc2 and cyclin B1 in AD. Both proteins were enriched in neurons with NFT and in neurons susceptible to NFT. An antibody specific for catalytically active cdc2 stained numerous NFT-containing neurons in AD but did not react with normal neurons. Double-labeling studies showed that active cdc2 and cyclin B1 coexist in AD neurons and co-localize with AD-specific mitotic phospho-epitopes. Mitotic kinase purified from AD and normal brain, using the yeast p13suc1 protein as affinity ligand, showed higher histone H1 phosphorylation activity in AD. Accordingly, the levels of cdc2 and cyclin B1 in p13suc1 fractions from AD were higher than normal. Consistent with a physiological relationship between NFT and mitotic kinase, NFT proteins co-purified with and became phosphorylated by the p13suc1-bound kinase in vitro. Furthermore, cdc2/cyclin B1 is the only one of several proline-directed kinases that created the TG/MC mitotic phospho-epitopes in recombinant tau in vitro. These findings suggest that aberrantly reexpressed cdc2/cyclin B1 in NFT-bearing neurons in AD brain contributes to the generation of M-phase phospho-epitopes in NFT.

Neurofibrillary tangles in the dentate granule cells of patients with Alzheimer's disease, Lewy body disease and progressive supranuclear palsy

Recent studies have shown that the dentate granular cells of the hippocampus are affected in patients with Alzheimer's disease (AD). To gain a better understanding of the cytoskeletal alterations in these cells, we carried out immunocytochemical and immunoelectron microscopic analysis of the dentate gyrus of patients with primary degenerative dementias, using a monoclonal antibody against paired helical filaments (TG3). This antibody labeled a large number of spherical inclusions in the dentate granule cells of patients with AD and its Lewy body variant (LBV). These inclusions consisted of straight tubular structures (about 18-25 nm in diameter), similar to those found in progressive supranuclear palsy (PSP). These inclusions, although in a smaller number, were also found in demented patients with PSP, but not in those with diffuse Lewy body disease or age-matched controls. These findings indicate that the neurofibrillary alterations in the dentate granule cells of patients with AD, LBV and PSP share cytoskeletal similarities.

Mitotic mechanisms in Alzheimer's disease?

The mechanism(s) leading to widespread hyper-phosphorylation of proteins in Alzheimer's disease (AD) are unknown. We have characterized seven new monoclonal antibodies recognizing independent phospho-epitopes in the paired helical filament proteins (PHF) found in AD brain. These antibodies show pronounced immunoreactivity with cultured human neuroblastoma cells that are in the M phase of cell division, but have no discernible reactivity with interphase cells. Immunoreactivity with these antibodies does not localize to the microtubule spindles or chromosomes in M phase, but is confined to the surrounding cytoplasm. Similar staining in M phase is observed with cultured cells of various tissue types and species. Cells arrested in M phase with the microtubule depolymerizing agent, nocodazole, show marked increases in immunoreactivity with the antibodies by immunofluorescence staining, ELISA, and immunoblotting. In neuroblastoma cells, the appearance of the TG/MC phospho-epitopes coincides with activation of mitotic protein kinases, but not with the activity of the neuronal specific cyclin-dependent kinase, cdk5. These data suggest that the TG/MC epitopes are conserved mitotic phospho-epitopes produced as a result of increased mitotic kinase activity. To investigate this possibility in AD, we examined the staining of human brain tissue with MPM-2, a marker antibody for mitotic phospho-epitopes. It was found that MPM-2 reacts strongly with neurofibrillary tangles, neuritic processes, and neurons in AD but has no staining in normal human brain. Our data suggest that accumulation of phospho-epitopes in AD may result from activation of mitotic posttranslational mechanisms which do not normally operate in mature neurons of brain.

Epitope expression and hyperphosphorylation of tau protein in corticobasal degeneration: differentiation from progressive supranuclear palsy

Corticobasal degeneration (CBD) is a rare, progressive neurological disorder characterized by widespread neuronal and glial accumulation of abnormal tau protein. Using immunohistochemistry we analyzed tau epitope expression and phosphorylation state in CBD and compared them to cytoskeletal changes in Alzheimer's disease (AD) and progressive supranuclear palsy (PSP). Epitopes spanning the entire length of the tau protein were present in CBD inclusions. An antibody against the alternatively spliced exon 3 did not recognize cytoskeletal lesions in CBD, but did in AD and PSP. Tau epitopes from each region of the molecule were present in cytoskeletal inclusions in CBD, including gray matter astrocytic plaques, gray and white matter threads, and oligodendroglial inclusions. As in AD, tau from CBD was highly phosphorylated. Antibodies that recognized phosphorylated tau epitopes reacted with material from CBD in a highly phosphatase-dependent manner. Again, all types of inclusions contained phosphorylated epitopes. We conclude that abnormal tau protein in CBD comprises the entire tau molecule and is highly phosphorylated, but is distinguished from AD and PSP by the paucity of epitopes contained in the alternatively spliced exon 3.

Correlations of synaptic and pathological markers with cognition of the elderly

It has been suggested that the physical basis for dementia is structural or functional loss of synapses. To confirm this finding, we performed an enzyme-linked immunoassay (ELISA) with a monoclonal antibody (EP10) to a synaptophysin-like protein in brain samples from 45 prospectively studied elderly subjects with an average age of 83.3 +/- 10.1 years. We compared the synaptic marker to immunoreactivity with a newly developed PHF antibody (TG3). The cases were selected on the basis of availability of frozen tissue, and included subjects ranging from clinically normal to end-stage dementia. As an initial assessment, we determined Pearson product moment correlations for two clinical measures--the Blessed test of information, concentration, and memory (BICM) and the Fuld object Memory Evaluation (FOME)--with ELISA data and with traditional pathologic markers. We found strong correlations (p < 0.01-0.001) for BICM with brain weight, neuronal loss in the basal nucleus of Meynert (nbM), counts of senile plaques (SP) in the neocortex and hippocampus, and neurofibrillary tangles (NFT) in all areas except the parahippocampal cortex. Except in the occipital lobe, where paired helical filament changes are relatively uncommon, TG3-immunoreactivity also correlated strongly with BICM. Weak correlations (p < 0.05) were found for BICM with EP10-immunoreactivity in only the temporal and parietal lobes. Only the pathologic variables showed any significant correlations with FOME. Because inclusion of normal subjects with few or no pathologic lesions could have been driving the strong correlations with pathologic markers, we limited the analysis to those subjects with dementia (BICM; 8). After making this correction, EP10-immunoreactivity in all cortical areas and the hippocampus correlated better (p < 0.05-0.01) with BICM but not FOME. The present univariate analysis suggests that synaptic markers may not be the best structural correlate of dementia and that markers indicative of cytoskeletal changes, e.g., SP, NFT and PHF protein accumulation, may be better correlates of dementia in the elderly.

TG-1: a marker for neuronal nuclei in Alzheimer's disease

TG-1 is a monoclonal antibody (mAb) raised against paired helical filaments purified from Alzheimer's Disease (AD) brain by immunoaffinity chromatography. By immunocytochemistry, TG-1 reveals abundant staining of neuronal nuclei in AD brain, but little or no staining in normal brain. TG-1 stained nuclei are observed in areas of AD brain with neurofibrillary pathology and in certain neurones that are not normally affected. Biochemical studies with TG-1 show antigens of 32-38 kDa in pellets and 50 kDa in supernatants from brain, with no obvious differences between normal and AD. TG-1 also recognizes an unusual structure, i.e., a 'starburst' in brain tissue from AD and elderly normals. Starbursts are not immunoreactive for the astrocytic marker, glial fibrillary acidic protein, and are not associated with amyloid. Widespread nuclear staining is observed with TG-1 in rat brain, and the immunoreactive antigens in purified nuclei are similar to those in human brain. Thus, TG-1 identifies neuronal nuclear antigens that are altered in AD, and provides a new avenue for studying pathogenic mechanisms in the disease.

Increased production of paired helical filament epitopes in a cell culture system reduces the turnover of tau

To investigate the regulation of posttranslational modifications of tau that might be pertinent to the production of the paired helical filament (PHF) of Alzheimer's disease, we incubated human neuroblastoma cells with the protein phosphatase inhibitor okadaic acid. This treatment results in increased immunoreactivity of tau with the monoclonal antibodies Alz-50, PHF-1, T3P, and NP8, a reduction in Tau-1 immunoreactivity, and an elevation in apparent molecular weight of tau. Moreover, our data demonstrate that accumulation of phosphates in tau leads to a decrease in the turnover rate of tau in the neuroblastoma cells. It is suggested that similar build-up of hyperphosphorylated tau in the neuronal perikarya may represent an early event in PHF formation. The present system facilitates the investigation of regulatory mechanisms governing the occurrence of PHF epitopes, their effects on neuronal cell metabolism, and possible pharmacological intervention.

Okadaic acid induces hyperphosphorylated forms of tau protein in human brain slices

Hyperphosphorylated forms of the microtubule-associated protein tau are components of the paired helical filaments (PHFs) seen in patients with Alzheimer's disease. Slices of human lateral temporal cortex were obtained from tissues removed incidental to resections for intractable hippocampal epilepsy. Tau phosphorylation in temporal lobe slices was determined using mobility shifts after sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunodetection with the monoclonal antibodies Alz-50, 5E2, and Tau-1. The results indicate that tau phosphorylation was altered in a dose-dependent manner by the phosphatase inhibitor okadaic acid, but not by N-methyl-D-aspartate, quisqualate, or kainate. The slowest mobility forms of tau, termed "PHF-like tau," produced by okadaic acid treatment were dephosphorylated by purified protein phosphatase 2B (calcineurin). Formation of PHF-like tau peptides was blocked by KN-62, 1[N,O-bis(1,5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpiperazi ne, an inhibitor of Ca2+/calmodulin-dependent protein kinase II. The protein kinase inhibitor staurosporine also prevented formation of PHF-like tau. These data suggest that phosphorylation of tau is regulated by Ca(2+)-dependent protein kinases and okadaic acid-sensitive protein phosphatases, alterations of which may be implicated in the pathogenesis of Alzheimer's disease.

Aluminum-induced decreases in choline acetyltransferase, tyrosine hydroxylase, and glutamate decarboxylase in selected regions of rabbit brain

The neuropathological and neurochemical effects of intracisternally administered aluminum-powder suspensions were studied in adult rabbits. The right half of each brain was fixed for neuropathological examination, and neurotransmitter-synthesizing enzyme activities were measured in homogenates of structures dissected from the left half of each brain. The neuropathological changes associated with aluminum-induced encephalomyelopathy, including neurofibrillary degeneration, were observed in several regions of the central nervous system of the aluminum-treated rabbits. The striatum was consistently free of changes. Decreases in choline acetyltransferase and tyrosine hydroxylase activities of more than 30% were observed in the striatum of animals within 14-21 d and at longer times after aluminum injection. The decrease in striatal choline acetyltransferase activity appears to be unrelated to pathological changes in the striatal cholinergic neurons. The decrease in tyrosine hydroxylase activity in the striatum may be unrelated to neuropathological changes in dopaminergic cell bodies in the midbrain. Significant decreases in glutamate decarboxylase activity in the cerebellum may be related to cell losses in this region, whereas choline acetyltransferase activity deficits in the whole hippocampus remain unexplained.