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AIM: The authors applied natural language processing and machine learning to explore the disease-related language patterns that warrant objective measures for assessing language ability in Japanese patients with Alzheimer disease (AD), while most previous studies have used large publicly available data sets in Euro-American languages. METHODS: The authors obtained 276 speech samples from 42 patients with AD and 52 healthy controls, aged 50 years or older. A natural language processing library for Python was used, spaCy, with an add-on library, GiNZA, which is a Japanese parser based on Universal Dependencies designed to facilitate multilingual parser development. The authors used eXtreme Gradient Boosting for our classification algorithm. Each unit of part-of-speech and dependency was tagged and counted to create features such as tag-frequency and tag-to-tag transition-frequency. Each feature's importance was computed during the 100-fold repeated random subsampling validation and averaged. RESULTS: The model resulted in an accuracy of 0.84 (SD = 0.06), and an area under the curve of 0.90 (SD = 0.03). Among the features that were important for such predictions, seven of the top 10 features were related to part-of-speech, while the remaining three were related to dependency. A box plot analysis demonstrated that the appearance rates of content words-related features were lower among the patients, whereas those with stagnation-related features were higher. CONCLUSION: The current study demonstrated a promising level of accuracy for predicting AD and found the language patterns corresponding to the type of lexical-semantic decline known as 'empty speech', which is regarded as a characteristic of AD. ispartof: PSYCHIATRY AND CLINICAL NEUROSCIENCES vol:77 issue:5 ispartof: location:Australia status: published

We propose a non-invasive and cost-effective method to automatically detect dementia by utilizing solely speech audio data. We extract paralinguistic features for a short speech segment and use Gated Convolutional Neural Networks (GCNN) to classify it into dementia or healthy. We evaluate our method on the Pitt Corpus and on our own dataset, the PROMPT Database. Our method yields the accuracy of 73.1% on the Pitt Corpus using an average of 114 seconds of speech data. In the PROMPT Database, our method yields the accuracy of 74.7% using 4 seconds of speech data and it improves to 80.8% when we use all the patient's speech data. Furthermore, we evaluate our method on a three-class classification problem in which we included the Mild Cognitive Impairment (MCI) class and achieved the accuracy of 60.6% with 40 seconds of speech data.

Artificial intelligence (AI) can provide many benefits in healthcare, including rapid and effective treatment options. However, previous research on human–computer interactions has demonstrated tha...

Introduction Studies have demonstrated the high agreement of several remote neuropsychological tests using video teleconferencing (VTC) with face-to-face (FTF) tests. However, the reliability of the remotely administered Alzheimer’s Disease Assessment Scale cognitive subscale (ADAS-cog), one of the most commonly used neuropsychological tests to detect cognitive decline, has not been substantially elucidated, particularly in Japanese populations. Therefore, this study aimed to evaluate the reliability of the remotely administered ADAS-cog compared with FTF-administered ADAS-cog among elderly Japanese participants. Methods Participants aged ≥60 years with and without cognitive impairment, i.e. those with mild cognitive impairment (MCI), those with dementia and healthy controls (HCs), were assessed with the ADAS-cog using VTC and FTF testing at an interval of >2 weeks and Results A total of 73 participants were included in the study (36 men; age, 76.3 ± 7.6 years). The ICC for the ADAS-cog total score was high in the entire sample (0.86), whereas ICCs were moderate to high for the subgroups (MCI: 0.63, dementia: 0.80 and HC: 0.74). Discussion The results indicate that a VTC-administered ADAS-cog could be an alternative for an FTF-administered ADAS-cog, although further replication studies with larger sample sizes and a wider range of cognitive functionalities are warranted.

Bacterial pathogens are able to survive within diverse habitats. The dynamic adaptation to the surroundings depends on their ability to sense environmental variations and to respond in an appropriate manner. This involves, among others, the activation of various cell-to-cell communication strategies. The capability of the bacterial cells to rapidly and co-ordinately set up an interplay with the host cells and/or with other bacteria facilitates their survival in the new niche. Efflux pumps are ubiquitous transmembrane transporters, able to extrude a large set of different molecules. They are strongly implicated in antibiotic resistance since they are able to efficiently expel most of the clinically relevant antibiotics from the bacterial cytoplasm. Besides antibiotic resistance, multidrug efflux pumps take part in several important processes of bacterial cell physiology, including cell to cell communication, and contribute to increase the virulence potential of several bacterial pathogens. Here, we focus on the structural and functional role of multidrug efflux pumps belonging to the Major Facilitator Superfamily (MFS), the largest family of transporters, highlighting their involvement in the colonization of host cells, in virulence and in biofilm formation. We will offer an overview on how MFS multidrug transporters contribute to bacterial survival, adaptation and pathogenicity through the export of diverse molecules. This will be done by presenting the functions of several relevant MFS multidrug efflux pumps in human life-threatening bacterial pathogens as Staphylococcus aureus, Listeria monocytogenes, Klebsiella pneumoniae, Shigella/E. coli, Acinetobacter baumannii.

This study aimed to clarify how behavioral and psychological symptoms of dementia (BPSD) and cognitive function affect the decision-making capacity of persons with Alzheimer's disease (AD) in a real informed consent situation about anti-dementia drug prescriptions. The participants were 76 patients with AD. We used the MacArthur Competence Assessment Tool to assess the capacity for consent to treatment (MacCAT-T). We simultaneously used the Mini-Mental State Examination, Executive Interview, Executive Clock Drawing Task, Logical Memory I of the Wechsler Memory Scale-Revised (LM I), LM II, and Neuropsychiatric Inventory (NPI) to assess cognitive function and psychiatric symptoms. We calculated the correlations between the MacCAT-T scores and the demographic, neuropsychological, and psychiatric variables. Once the univariable correlations were determined, we performed simple linear regression analyses to examine if the regression equations were significant. In the final analyses, we incorporated significant variables into stepwise multiple linear regression analyses to determine the most significant predictors of mental capacity. Age (β = −0.34), anxiety (β = −0.27), and LM I (β = 0.26) were significant predictors of “understanding” (adjusted R2 = 0.29). LM II (β = 0.39), anxiety (β = −0.29), and education (β = 0.21) were significant predictors of “understanding of alternative treatments” (adjusted R2 = 0.30). Anxiety (β = −0.36) and age (β = −0.22) were significant predictors of “appreciation” (adjusted R2 = 0.18). Age (β = −0.31) and anxiety (β = −0.28) were significant predictors of explained variance in “reasoning” (adjusted R2 = 0.17). Patients with anxiety had lower scores on all five MacCAT-T subscales: “understanding,” without 3.8 [SD = 1.2] vs. with 2.6 [SD = 1.1]; “understanding of alternative treatments,” without 2.9 [SD = 2.2] vs. with 1.3 [SD = 1.8]; “appreciation,” without 2.9 [SD = 1.1] vs. with 1.9 [SD = 1.2]; “reasoning,” without 4.0 [SD = 2.0] vs. with 2.7 [SD = 1.7]; and “expressing a choice,” without 1.9 [SD = 0.4] vs. with 1.5 [SD = 0.6]. Considering the effects of BPSD, cognitive function, and age/education when assessing consent capacity in persons with AD is important. Reducing anxiety may contribute to improved capacity in persons with AD.

Aim Few cohort studies targeting the oldest-old individuals have been carried out. The subiculum in the hippocampus is thought to be related to memory function, and atrophy of this structure might result in the conversion from amnestic mild cognitive impairment to Alzheimer's disease. Thus, we sought to examine the relationship between subiculum volumes and memory function in individuals aged ≥95 years, using a novel cognitive examination called the Addenbrooke's Cognitive Examination III (ACE-III) and an advanced magnetic resonance imaging analytical method, Multiple Automatically Generated Templates Brain Segmentation Algorithm (MAGeTbrain), to measure hippocampal subfield volumes. Methods A part of the cohort data of the Arakawa 95+ study for the oldest-old aged ≥95 years was used. A total of 10 individuals completed all of the examinations. The MAGeT brain was applied to estimate the subfield volumes of the hippocampus. Correlation analyses and multiple regression analyses were carried out to examine a relationship among ACE-III memory scores and the subfield volumes in the hippocampus, including the subiculum. Results There was a significant relationship between ACE-III memory scores and subdivision volumes. Regression analyses showed that subiculum volumes were associated with ACE-III memory scores in the oldest-old individuals (β = 0.721, P = 0.019; F1, 8 = 8.67, adjusted R2 = 0.46). Conclusions The subiculum might play a pivotal role in memory function in the oldest-old individuals aged ≥95 years. The present finding warrants further research including larger sample sizes. Geriatr Gerontol Int 2019; 19: 347-351.

The EvgS/EvgA two-component signal transduction system inEscherichia coliis activated under mildly acidic pH conditions. Upon activation, this system induces the expression of a number of genes that confer acid resistance. The EvgS histidine kinase sensor has a large periplasmic domain that is required for perceiving acidic signals. In addition, we have previously proposed that the cytoplasmic linker region of EvgS is also involved in the activation of this sensor. The cytoplasmic linker region resembles a Per-ARNT-Sim (PAS) domain, which is known to act as a molecular sensor that is responsive to chemical and physical stimuli and regulates the activity of diverse effector domains. Our EvgS/EvgA reporter assays revealed that under EvgS-activating mildly acidic pH conditions, EvgS was activated only during aerobic growth conditions, and not during anaerobic growth. Studies using EvgS mutants revealed that C671A and C683A mutations in the cytoplasmic PAS domain activated EvgS even under anaerobic conditions. Furthermore, among the electron carriers of the electron transport chain, ubiquinone was required for EvgS activation. The present study proposes a model of EvgS activation by oxidation and suggests that the cytoplasmic PAS domain serves as an intermediate redox switch for this sensor.

BackgroundDepressive and neurocognitive disorders are debilitating conditions that account for the leading causes of years lived with disability worldwide. Overcoming these disorders is an extremely important public health problem today. However, there are no biomarkers that are objective or easy-to-obtain in daily clinical practice, which leads to difficulties in assessing treatment response and developing new drugs. Due to advances in technology, it has become possible to quantify important features that clinicians perceive as reflective of disorder severity. Such features include facial expressions, phonic/speech information, body motion, daily activity, and sleep. The overall goal of this proposed study, the Project for Objective Measures Using Computational Psychiatry Technology (PROMPT), is to develop objective, noninvasive, and easy-to-use biomarkers for assessing the severity of depressive and neurocognitive disorders.MethodsThis is a multi-center prospective study. DSM-5 criteria for major depressive disorder, bipolar disorder, and major and minor neurocognitive disorders are inclusion criteria for the depressive and neurocognitive disorder samples. Healthy samples are confirmed to have no history of psychiatric disorders by Mini-International Neuropsychiatric Interview, and have no current cognitive decline based on the Mini Mental State Examination. Participants go through approximately 10-minute interviews with a psychiatrist/psychologist, where participants talk about non-specific topics such as everyday living, symptoms of disease, hobbies, etc. Interviews are recorded using RGB and infrared cameras, and an array microphone. As an option, participants are asked to wear wrist-band type devices during the observational period. The interviews take place ≤10 times within up to five years of follow-up. Various software is used to process the raw video, voice, infrared, and wearable device data. A machine learning approach is used to predict the presence of symptoms, severity, and the improvement/deterioration of symptoms.DiscussionThe PROMPT goal is to develop objective digital biomarkers for assessing the severity of depressive and neurocognitive disorders in the hopes of guiding decision-making in clinical settings as well as reducing the risk of clinical trial failure. Challenges may include the large variability of samples, which makes it difficult to extract the features that commonly reflect disorder severity.Trial RegistrationUMIN000021396, University Hospital Medical Information Network (UMIN)

Induction of the AR2 acid response system of Escherichia coli occurs at a moderately low pH (pH 5.5) and leads to high levels of resistance to pH levels below 2.5 in the presence of glutamate. Induction is mediated in part by the EvgAS two component system. Here, we show that the bacterial signaling molecule indole inhibits the induction of key promoters in the AR2 system and blocks the development of glutamate-dependent acid resistance. The addition of tryptophan, the precursor for indole biosynthesis, had the same effects, and this block was relieved in a tnaA mutant, which is unable to synthesize indole. Expression of a constitutively active EvgS protein was able to relieve the inhibition caused by indole, consistent with EvgS being inhibited directly or indirectly by indole. Indole had no effect on autophosphorylation of the isolated cytoplasmic domain of EvgS. This is consistent with a model where indole directly or indirectly affects the ability of EvgS to detect its inducing signal or to transduce this information across the cytoplasmic membrane. The inhibitory activity of indole on the AR2 system is not related to its ability to act as an ionophore, and, conversely, the ionophore CCCP had no effect on acid-induced AR2 promoter activity, showing that the proton motive force is unlikely to be a signal for induction of the AR2 system.

Two-component signal transduction systems (TCSs), consisting of a histidine kinase (HK) and its cognate response regulator, are ubiquitous among bacteria and are associated with the virulence of pathogens. TCSs are potential targets for alternative antibiotics and antivirulence agents. It is, thus, very important to determine HK activity in bacterial TCSs. Here, we describe an immuno-dot blot assay for the inhibition profiling of HKs using the anti-N3-phosphohistidine antibody. This simple method promises reliable detection of HK activity, and it is likely applicable in high-throughput screening of HK inhibitors.

AIM To investigate the influence of replacing sedentary time with physical activity on cognitive function using an isotemporal substitution model in a population of community-dwelling oldest old. METHODS This cross-sectional study included residents of the Arakawa ward, Tokyo, who were part of a prospective cohort from the Arakawa 85+ study. We measured physical activity in 136 participants using a triaxial actigraph. Cognitive function was measured using the Addenbrooke's Cognitive Examination-III and participants were divided into a "cognitive decline group" (Addenbrooke's Cognitive Examination-III ≤88) and "cognitive maintain group" (Addenbrooke's Cognitive Examination-III ≥89). Physical activity was divided into three categories: sedentary behavior (≤1.5 metabolic equivalents), light physical activity (>1.5 to

Objectives As the population of patients with cognitive decline grows, physicians and caregivers need brief screening tools. Comprehensive neurocognitive batteries require special training and time for evaluation. We focused on accessibility and compared the diagnostic power of several easy questions. Design "Attended With" (AW) and "Head-Turning Sign" (HTS) factors and participants' replies to following questions were recorded: "Do you feel that you have more difficulties in your daily life than you used to?", [no consciousness (C-) or consciousness+ (C+)], "Could you tell me about your daily pleasures or pastimes?" [no pleasure (P-) or pleasure + (P+)], "What are notable current/recent news/topics?" [no news (N-) or news+ (N+)]. Setting This took place in our Memory Clinic between May 2016 and July 2019. Participants We enrolled 162 consecutive cases (44 cognitive normal (CN), 55 amnestic mild cognitive impairment (aMCI), and 48 Alzheimer's disease (AD)). Measurements The sensitivity and specificity of each battery were calculated, and on account of those numbers, the population attributable risk percent % (PAR%) of (AW and HTS+), (C- and P-), (C- and N-), (P- and N-) as analysis of combination of questions, respectively, were calculated. Results AW had high sensitivity, 87.4, 95.8% (CN vs aMCI + AD, CN + aMCI vs AD) but the sensitivity of HTS was only 46.4, 57.7%, and HTS showed high specificity, 100.0, 71.8%. C- had high sensitivity, 80.6, 87.5%, whereas P- and N- had high specificity, both 83.9% in CN vs aMCI + AD, 88.1% and 75.9% in CN + aMCI vs AD, respectively. In combination analysis, the PAR% of (C- and N-) were as high as (AW and HTS+). Conclusions The combination of (C- and N-) is as powerful as (AW and HTS+) in screening AD. Our findings provide novel insights for screening utility of brief questions "Consciousness of Impairment" and "Recent News."

Background: In an aging society, neuropsychological testing using video teleconferencing (VTC) is increasingly important. Despite the potential benefit of a VTC-administered Montreal Cognitive Asse...

Recently, the number of people who are diagnosed as mental diseases is increasing. Efficient and objective diagnosis is important to start medical treatments in earlier stages. However, mental disease diagnosis is difficult to quantify criteria, because it is performed through conversations with patients, not by physical surveys. We aim to automate mental disease diagnosis in order to resolve these issues. We recorded conversations between psychologists and subjects to build our diagnosis speech corpus. Our subjects include healthy persons, people with mental diseases of depression, bipolar disorder, schizophrenia, anxiety and dementia. All of our subjects are diagnosed by doctors of psychiatry. Then we made accurate transcription manually, adding utterance time stamps, linguistic and non-linguistic annotations. Using our corpus, we performed feature analysis to find characteristics for each disease. We also tried automatic mental disease diagnosis by machine learning, while the number of sample data is few because we were still in our pilot study phase. We will increase the number of subjects in future.

In the bacterial signaling mechanisms known as two-component systems (TCSs), signals are generally conveyed by means of a His-Asp phosphorelay. Each system consists of a histidine kinase (HK) and its cognate response regulator. Because of the labile nature of phosphorylated His and Asp residues, few approaches are available that permit a quantitative analysis of their phosphorylation status. Here, we show that the Phos-tag dye technology is suitable for the fluorescent detection of His- and Asp-phosphorylated proteins separated by SDS-PAGE. The dynamics of the His-Asp phosphorelay of recombinant EnvZ-OmpR, a TCS derived from Escherichia coli, were examined by SDS-PAGE followed by simple rapid staining with Phos-tag Magenta fluorescent dye. The technique permitted not only the quantitative monitoring of the autophosphorylation reactions of EnvZ and OmpR in the presence of adenosine triphosphate (ATP) or acetyl phosphate, respectively, but also that of the phosphotransfer reaction from EnvZ to OmpR, which occurs within 1 min in the presence of ATP. Furthermore, we demonstrate profiling of waldiomycin, an HK inhibitor, by using the Phos-tag Cyan gel staining. We believe that the Phos-tag dye technology provides a simple and convenient fluorometric approach for screening of HK inhibitors that have potential as new antimicrobial agents.

Aim The aim of this study was to examine sociopsychological characteristics of the oldest old in Japan. We conducted a baseline survey of a community-based cohort of persons aged 95 or older. Methods Participants were aged 95+ years and resided in Arakawa Ward in Tokyo on 1 January 2016. We mailed a questionnaire to these individuals to assess their physical, mental, and social status. Subsequently, if respondents agreed, we conducted in-home interviews and examined their physical and cognitive function. Also, we mailed non-respondents a simplified version of full questionnaire. Additionally, we examined the basic registered data of the study population and the status of their Long-term Care Insurance. Data at baseline and 1-year follow-up were compared. Results With regard to Long-term Care Insurance, 423 residents aged 95+ years (78.0%) were on long-term care level, 35 (6.5%) were on support level, and 84 (15.5%) did not require support. At the 1-year follow-up, 275 (50.7%) had the same care level, 107 (19.7%) required a greater level of care, and 131 had died (annual death rate: 24.2%). Compared to the simplified questionnaire group (n = 128) and the full questionnaire-only group (n = 14), a higher proportion of respondents who had completed the full questionnaire and had in-home interviews (n = 26) were men, lived only with a spouse, had higher activities of daily living, and reported more positive feelings and well-being. Conclusions In the late nonagenarian population, the annual death rate was high, and care needs increased rapidly. However, some persons maintained the same care level or even showed improvement and successful ageing.

Purpose: Current healthcare systems are not suitable for serving future societies in which the oldest old are commonplace. The objective of this study was to understand what the oldest old care most about in their daily lives. Methods: Semi-structured in-depth interviews and thematic analysis were used. Face-to-face interviews were conducted in 17 elderly residents (≥ 95 years) of Arakawa-ku, Tokyo, Japan from July to November 2017. Results: Three themes emerged from the interview responses: “unshakable beliefs and social ties,” “natural acceptance,” and “my day-to-day life with precious moments.” The oldest old strongly believe in diligence and compassion and maintain strong relationships with people around them. Despite their small social networks, they are concerned about future society. They accept their selves and their lives, including their impending deaths. Despite their functional decline, they control their lives by making very small decisions. They live on a moment-to-moment basis, cherishing simple events. Conclusion: Maintaining autonomy through making small decisions and enjoying small pleasures are important to the oldest old. Understanding the needs of the oldest old is the first step towards developing optimal geriatric care for an aging population.

Two-component signal transduction systems (TCSs) represent one of the primary means by which bacteria sense and respond to changes in their environment, both intra- and extracellular. The highly conserved WalK (histidine kinase)/WalR (response regulator) TCS is essential for cell wall metabolism of low G+C Gram-positive bacteria and acts as a master regulatory system in controlling and coordinating cell wall metabolism with cell division. Waldiomycin, a WalK inhibitor, has been discovered by screening metabolites from actinomycetes and belongs to the family of angucycline antibiotics. In the present study, we have shown that waldiomycin inhibited autophosphorylation of WalK histidine kinases in vitro from Bacillus subtilis, Staphylococcus aureus, Enterococcus faecalis, and Streptococcus mutans at half-maximal inhibitory concentrations of 10.2, 8.8, 9.2, and 25.8 μM, respectively. Quantitative RT-PCR studies of WalR regulon genes have suggested that waldiomycin repressed the WalK/WalR system in B. subtilis and S. aureus cells. Morphology of waldiomycin-treated S. aureus cells displayed increased aggregation instead of proper cellular dissemination. Furthermore, autolysis profiles of S. aureus cells revealed that waldiomycin-treated cells were highly resistant to Triton X-100- and lysostaphin-induced lysis. These phenotypes are consistent with those of cells starved for the WalK/WalR system, indicating that waldiomycin inhibited the autophosphorylation activity of WalK in cells. We have also confirmed that waldiomycin inhibits WalK autophosphorylation in vivo by actually observing the phosphorylated WalK ratio in cells using Phos-tag SDS-PAGE. The results of our current study strongly suggest that waldiomycin targets WalK histidine kinases and inhibits the WalR regulon genes expression, thereby affecting both cell wall metabolism and cell division.

Background Despite a steady increase in life expectancy, a few studies have investigated cross-sectional correlates and longitudinal predictors of cognitive function, a core domain of the successful aging, among socio-clinico-demographic factors in the oldest-old exclusively. Objectives The aims of this study were to examine socio-clinico-demographic characteristics associated with global cognition and its changes in the oldest-old. Methods We reanalyzed a dataset of cognitively preserved community-dwelling subjects aged 85 years and older in the Tokyo Oldest Old Survey on Total Health, a 6-year longitudinal observational study. This study consisted of (1) baseline cross-sectional analyses examining correlates of global cognition (n = 248) among socio-clinico-demographic factors and (2) longitudinal analyses examining baseline predictors for changes of global cognition in 3-year follow-up (n = 195). The Mini-Mental State Examination was used as a screening test to assess global cognition. Results At baseline, higher weights were related to higher cognitive function in the oldest-old. The baseline predictors of global cognitive decline in 3-year follow-up were higher global cognition, shorter education period, and lower sociocultural activities and lower instrumental activity of daily living, in this order. Conclusions The present study suggests that it is crucial to attain higher education during early life and avoid leanness or obesity, participate in sociocultural cognitive activities during late life, and maintain instrumental activity of daily living to preserve optimal cognitive function in the oldest-old, which will facilitate developing prevention strategies for cognitive decline and promoting successful aging in this increasing population.

The WalK/WalR two-component system is essential for cell wall metabolism and thus for cell growth in Bacillus subtilis. Waldiomycin was previously isolated as an antibiotic that targeted WalK, the cognate histidine kinase (HK) of the response regulator, WalR, in B. subtilis. To gain further insights into the action of waldiomycin on WalK and narrow down its site of action, mutations were introduced in the H-box region, a well-conserved motif of the bacterial HKs of WalK. The half-maximal inhibitory concentrations (IC

Two-component signal transduction systems (TCSs) in bacteria perceive environmental stress and transmit the information via phosphorelay to adjust multiple cellular functions for adaptation. The EvgS/EvgA system is a TCS that confers acid resistance to Escherichia coli cells. Activation of the EvgS sensor initiates a cascade of transcription factors, EvgA, YdeO, and GadE, which induce the expression of a large group of acid resistance genes. We searched for signals activating EvgS and found that a high concentration of alkali metals (Na + , K + ) in addition to low pH was essential for the activation. EvgS is a histidine kinase, with a large periplasmic sensor region consisting of two tandem PBPb (bacterial periplasmic solute-binding protein) domains at its N terminus. The periplasmic sensor region of EvgS was necessary for EvgS activation, and Leu152, located within the first PBPb domain, was involved in the activation. Furthermore, chimeras of EvgS and PhoQ histidine kinases suggested that alkali metals were perceived at the periplasmic sensor region, whereas the cytoplasmic linker domain, connecting the transmembrane region and the histidine kinase domain, was required for low-pH perception.

The characteristic neuropathological changes in Alzheimer's disease (AD) are deposition of amyloid senile plaques and neurofibrillary tangles. The (18)F-labeled amyloid tracer, [(18)F]2-[(2-{(E)-2-[2-(dimethylamino)-1,3-thiazol-5-yl]vinyl}-1,3-benzoxazol-6-yl)oxy]-3-fluoropropan-1-ol (FACT), one of the benzoxazole derivatives, was recently developed. In the present study, deposition of amyloid senile plaques was measured by positron emission tomography (PET) with both [(11)C]Pittsburgh compound B (PIB) and [(18)F]FACT in the same subjects, and the regional uptakes of both radiotracers were directly compared.Two PET scans, one of each with [(11)C]PIB and [(18)F]FACT, were performed sequentially on six normal control subjects, two mild cognitive impairment (MCI) patients, and six AD patients. The standardized uptake value ratio of brain regions to the cerebellum was calculated with partial volume correction using magnetic resonance (MR) images to remove the effects of white matter accumulation.No significant differences in the cerebral cortical uptake were observed between normal control subjects and AD patients in [(18)F]FACT studies without partial volume correction, while significant differences were observed in [(11)C]PIB. After partial volume correction, the cerebral cortical uptake was significantly larger in AD patients than in normal control subjects for [(18)F]FACT studies as well as [(11)C]PIB. Relatively lower uptakes of [(11)C]PIB in distribution were observed in the medial side of the temporal cortex and in the occipital cortex as compared with [(18)F]FACT. Relatively higher uptake of [(11)C]PIB in distribution was observed in the frontal and parietal cortices.Since [(18)F]FACT might bind more preferentially to dense-cored amyloid deposition, regional differences in cerebral cortical uptake between [(11)C]PIB and [(18)F]FACT might be due to differences in regional distribution between diffuse and dense-cored amyloid plaque shown in the autoradiographic and histochemical assays of postmortem AD brain sections.

The PhoQ/PhoP two-component signal transduction system in Escherichia coli is activated by SafA, a small membrane protein that modifies the PhoQ histidine kinase. The SafA C-terminal domain (41-65 aa) interacts directly with the sensory domain of PhoQ at the periplasm. We used in vitro and in vivo strategies to elucidate the way SafA modifies the PhoQ/PhoP phosphorelay system. First, the enzymatic activities of membranes from cells overexpressing PhoQ and cells expressing both PhoQ and SafA were compared in vitro. Increased autophosphorylation of PhoQ was observed in the presence of SafA, but it did not increase the dephosphorylation of phospho-PhoP by PhoQ. In addition, SafA increased the phospho-PhoP level on the phosphotransfer assay. We confirmed that induction of SafA results in an accumulation of phospho-PhoP in vivo by the Phos-tag system. Our results suggest that the accumulation of phospho-PhoP is linked to activation of PhoQ autophosphorylation by SafA.

Two-component signal transduction systems (TCSs), composed of a histidine kinase sensor (HK) and its cognate response regulator, sense and respond to environmental changes and are related to the virulence of pathogens. TCSs are potential targets for alternative antibiotics and anti-virulence agents. Here we found that waldiomycin, an angucycline antibiotic that inhibits a growth essential HK, WalK, in Gram-positive bacteria, also inhibits several class I HKs from the Gram-negative Escherichia coli. NMR analyses and site-directed mutagenesis studies using the osmo-sensing EnvZ, a prototypical HK of E. coli, showed that waldiomycin directly binds to both H-box and X-region, which are the two conserved regions in the dimerization-inducing and histidine-containing phosphotransfer (DHp) domain of HKs. Waldiomycin inhibits phosphorylation of the conserved histidine in the H-box. Analysis of waldiomycin derivatives suggests that the angucyclic ring, situated near the H-box in the waldiomycin-EnvZ DHp domain complex model, is responsible for the inhibitory activity. We demonstrate that waldiomycin is an HK inhibitor binding to the H-box region and has the potential of inhibiting a broad spectrum of HKs.