The Aß(1-38) peptide is a negative regulator of the Aß(1-42) peptide implicated in Alzheimer disease progression.

The pool of ß-Amyloid (Aß) length variants detected in preclinical and clinical Alzheimer disease (AD) samples suggests a diversity of roles for Aß peptides. We examined how a naturally occurring variant, e.g. Aß(1-38), interacts with the AD-related variant, Aß(1-42), and the predominant physiological variant, Aß(1-40). Atomic force microscopy, Thioflavin T fluorescence, circular dichroism, dynamic light scattering, and surface plasmon resonance reveal that Aß(1-38) interacts differently with Aß(1-40) and Aß(1-42) and, in general, Aß(1-38) interferes with the conversion of Aß(1-42) to a ß-sheet-rich aggregate. Functionally, Aß(1-38) reverses the negative impact of Aß(1-42) on long-term potentiation in acute hippocampal slices and on membrane conductance in primary neurons, and mitigates an Aß(1-42) phenotype in Caenorhabditis elegans. Aß(1-38) also reverses any loss of MTT conversion induced by Aß(1-40) and Aß(1-42) in HT-22 hippocampal neurons and APOE ε4-positive human fibroblasts, although the combination of Aß(1-38) and Aß(1-42) inhibits MTT conversion in APOE ε4-negative fibroblasts. A greater ratio of soluble Aß(1-42)/Aß(1-38) [and Aß(1-42)/Aß(1-40)] in autopsied brain extracts correlates with an earlier age-at-death in males (but not females) with a diagnosis of AD. These results suggest that Aß(1-38) is capable of physically counteracting, potentially in a sex-dependent manner, the neuropathological effects of the AD-relevant Aß(1-42).

Assessing Lysosomal Alkalinization in the Intestine of Live Caenorhabditis elegans.

The nematode Caenorhabditis elegans (C. elegans) is a model system that is widely used to study longevity and developmental pathways. Such studies are facilitated by the transparency of the animal, the ability to do forward and reverse genetic assays, the relative ease of generating fluorescently labeled proteins, and the use of fluorescent dyes that can either be microinjected into the early embryo or incorporated into its food (E. coli strain OP50) to label cellular organelles (e.g. 9-diethylamino-5H-benzo(a)phenoxazine-5-one and (3-{2-[(1H,1'H-2,2'-bipyrrol-5-yl-kappaN(1))methylidene]-2H-pyrrol-5-yl-kappaN}-N-[2-(dimethylamino)ethyl]propanamidato)(difluoro)boron). Here, we present the use of a fluorescent pH-sensitive dye that stains intestinal lysosomes, providing a visual readout of dynamic, physiological changes in lysosomal acidity in live worms. This protocol does not measure lysosomal pH, but rather aims to establish a reliable method of assessing physiological relevant variations in lysosomal acidity. cDCFDA is a cell-permeant compound that is converted to the fluorescent fluorophore 5-(and-6)-carboxy-2',7'-dichlorofluorescein (cDCF) upon hydrolysis by intracellular esterases. Protonation inside lysosomes traps cDCF in these organelles, where it accumulates. Due to its low pKa of 4.8, this dye has been used as a pH sensor in yeast. Here we describe the use of cDCFDA as a food supplement to assess the acidity of intestinal lysosomes in C. elegans. This technique allows for the detection of alkalinizing lysosomes in live animals, and has a broad range of experimental applications including studies on aging, autophagy, and lysosomal biogenesis.

Rapid Nuclear Exclusion of Hcm1 in Aging Saccharomyces cerevisiae Leads to Vacuolar Alkalization and Replicative Senescence.

The yeast, Saccharomyces cerevisiae, like other higher eukaryotes, undergo a finite number of cell divisions before exiting the cell cycle due to the effects of aging. Here, we show that yeast aging begins with the nuclear exclusion of Hcm1 in young cells, resulting in loss of acidic vacuoles. Autophagy is required for healthy aging in yeast, with proteins targeted for turnover by autophagy directed to the vacuole. Consistent with this, vacuolar acidity is necessary for vacuolar function and yeast longevity. Using yeast genetics and immunofluorescence microscopy, we confirm that vacuolar acidity plays a critical role in cell health and lifespan, and is potentially maintained by a series of Forkhead Box (Fox) transcription factors. An interconnected transcriptional network involving the Fox proteins (Fkh1, Fkh2 and Hcm1) are required for transcription of v-ATPase subunits and vacuolar acidity. As cells age, Hcm1 is rapidly excluded from the nucleus in young cells, blocking the expression of Hcm1 targets (Fkh1 and Fkh2), leading to loss of v-ATPase gene expression, reduced vacuolar acidification, increased α-syn-GFP vacuolar accumulation, and finally, diminished replicative lifespan (RLS). Loss of vacuolar acidity occurs about the same time as Hcm1 nuclear exclusion and is conserved; we have recently demonstrated that lysosomal alkalization similarly contributes to aging in C. elegans following a transition from progeny producing to post-reproductive life. Our data points to a molecular mechanism regulating vacuolar acidity that signals the end of RLS when acidification is lost.

Chemical Composition and Antibacterial Activity of the Essential Oil of Vitex agnus-castus L. (Lamiaceae).

Abnormal multiplication of oral bacteria causes dental caries and dental plaque. These diseases continue to be major public health concerns worldwide, mainly in developing countries. In this study, the chemical composition and antimicrobial activity of the essential oil of Vitex agnus-castus leaves (VAC‒EO) collected in the North of Brazil against a representative panel of cariogenic bacteria were investigated. The antimicrobial activity of VAC-EO was evaluated in terms of its minimum inhibitory concentration (MIC) values by using the broth microdilution method in 96-well microplates. The chemical constituents of VAC-EO were identified by gas chromatography (GC‒FID) and gas chromatography‒mass spectrometry (GC‒MS). VAC‒EO displayed some activity against all the investigated oral pathogens; MIC values ranged from 15.6 to 200 µg/mL. VAC-EO had promising activity against Streptococcus mutans (MIC= 15.6 µg/mL), Lactobacillus casei (MIC= 15.6 µg/mL), and Streptococcus mitis (MIC= 31.2 µg/mL). The compounds 1,8-cineole (23.8%), (E)-ß-farnesene (14.6%), (E)-caryophyllene (12.5%), sabinene (11.4%), and α-terpinyl acetate (7.7%) were the major chemical constituents of VAC‒EO. VAC-EO displays antimicrobial activity against cariogenic bacteria. The efficacy of VAC-EO against S. mutans is noteworthy and should be further investigated.

Chemical Composition and Antibacterial Activity of the Essential Oil of Vitex agnus-castus L. (Lamiaceae)

ABSTRACT Abnormal multiplication of oral bacteria causes dental caries and dental plaque. These diseases continue to be major public health concerns worldwide, mainly in developing countries. In this study, the chemical composition and antimicrobial activity of the essential oil of Vitex agnus-castus leaves (VAC‒EO) collected in the North of Brazil against a representative panel of cariogenic bacteria were investigated. The antimicrobial activity of VAC-EO was evaluated in terms of its minimum inhibitory concentration (MIC) values by using the broth microdilution method in 96-well microplates. The chemical constituents of VAC-EO were identified by gas chromatography (GC‒FID) and gas chromatography‒mass spectrometry (GC‒MS). VAC‒EO displayed some activity against all the investigated oral pathogens; MIC values ranged from 15.6 to 200 μg/mL. VAC-EO had promising activity against Streptococcus mutans (MIC= 15.6 μg/mL), Lactobacillus casei (MIC= 15.6 μg/mL), and Streptococcus mitis (MIC= 31.2 μg/mL). The compounds 1,8-cineole (23.8%), (E)-β-farnesene (14.6%), (E)-caryophyllene (12.5%), sabinene (11.4%), and α-terpinyl acetate (7.7%) were the major chemical constituents of VAC‒EO. VAC-EO displays antimicrobial activity against cariogenic bacteria. The efficacy of VAC-EO against S. mutans is noteworthy and should be further investigated.

Regulation of Lysosomal Function by the DAF-16 Forkhead Transcription Factor Couples Reproduction to Aging in Caenorhabditis elegans.

Aging in eukaryotes is accompanied by widespread deterioration of the somatic tissue. Yet, abolishing germ cells delays the age-dependent somatic decline in Caenorhabditis elegans In adult worms lacking germ cells, the activation of the DAF-9/DAF-12 steroid signaling pathway in the gonad recruits DAF-16 activity in the intestine to promote longevity-associated phenotypes. However, the impact of this pathway on the fitness of normally reproducing animals is less clear. Here, we explore the link between progeny production and somatic aging and identify the loss of lysosomal acidity-a critical regulator of the proteolytic output of these organelles-as a novel biomarker of aging in C. elegans The increase in lysosomal pH in older worms is not a passive consequence of aging, but instead is timed with the cessation of reproduction, and correlates with the reduction in proteostasis in early adult life. Our results further implicate the steroid signaling pathway and DAF-16 in dynamically regulating lysosomal pH in the intestine of wild-type worms in response to the reproductive cycle. In the intestine of reproducing worms, DAF-16 promotes acidic lysosomes by upregulating the expression of v-ATPase genes. These findings support a model in which protein clearance in the soma is linked to reproduction in the gonad via the active regulation of lysosomal acidification.

Age-related differences on low back pain and postural control during one-leg stance: a case-control study.

BACKGROUND AND PURPOSE: The prevalence of chronic low back pain (CLBP) is higher in older than in younger adults and is associated with poor postural control and falls. The objective of this study was to compare the postural control of younger and older subjects with and without CLBP during a one-leg stance. METHODS: Twenty subjects with and 20 subjects without nonspecific CLBP participated in the study. Each group contained 10 younger (50% males; mean age: 31 years) and 10 older adults (50% males; mean age 71 years). The subjects performed three 30-s trials of a one-leg stance on a force platform. Balance parameters were computed to quantify postural control, including center of pressure (COP) area, mean velocity, and mean frequency in the anteroposterior and mediolateral directions. RESULTS: Participants with CLBP presented significantly poorer balance (P < 0.05) than participants without CLBP. The effect size was large for younger adults (d = 1.44) and small for older adults (d = 0.40). Older adults with CLBP presented poorer balance than younger adults with CLBP (large effect size, d = 1.24). CONCLUSIONS: The findings indicate that CLBP affects the balance of both younger and older adults, and that the age-related changes also affect balance and modify the magnitude of CLBP effects on balance.

A Genome Scale Screen for Mutants with Delayed Exit from Mitosis: Ire1-Independent Induction of Autophagy Integrates ER Homeostasis into Mitotic Lifespan.

Proliferating eukaryotic cells undergo a finite number of cell divisions before irreversibly exiting mitosis. Yet pathways that normally limit the number of cell divisions remain poorly characterized. Here we describe a screen of a collection of 3762 single gene mutants in the yeast Saccharomyces cerevisiae, accounting for 2/3 of annotated yeast ORFs, to search for mutants that undergo an atypically high number of cell divisions. Many of the potential longevity genes map to cellular processes not previously implicated in mitotic senescence, suggesting that regulatory mechanisms governing mitotic exit may be broader than currently anticipated. We focused on an ER-Golgi gene cluster isolated in this screen to determine how these ubiquitous organelles integrate into mitotic longevity. We report that a chronic increase in ER protein load signals an expansion in the assembly of autophagosomes in an Ire1-independent manner, accelerates trafficking of high molecular weight protein aggregates from the cytoplasm to the vacuoles, and leads to a profound enhancement of daughter cell production. We demonstrate that this catabolic network is evolutionarily conserved, as it also extends reproductive lifespan in the nematode Caenorhabditis elegans. Our data provide evidence that catabolism of protein aggregates, a natural byproduct of high protein synthesis and turn over in dividing cells, is among the drivers of mitotic longevity in eukaryotes.

Relationship between foot posture measurements and force platform parameters during two balance tasks in older and younger subjects.

[Purpose] The aim of this study was to compare age-related differences in balance and anthropometric posture measurements of the foot and to determine any relationship between them. [Subjects and Methods] Sixty-eight older and 42 younger adults participated in this study. Foot posture was tested for four domains: 1) hallux flexion and extension range of motion using a goniometer, 2) navicular height and 3) length of the foot using a pachymeter, and 4) footprint (width of forefoot, arch index and hallux valgus). Balance was tested under two conditions on a force platform: bipodal in 60-s trials and unipodal in 30-s trials. The sway area of the center of pressure and velocity in the anteroposterior and mediolateral directions were computed. [Results] Older individuals showed significantly poorer balance compared with younger adults under in the unipodal condition (center of pressure area 9.97 vs. 7.72 cm(2)). Older people presented a significantly lower hallux mobility and higher values for width of the forefoot and transverse arch index than younger adults. The correlations between all foot posture and center of pressure parameters varied across groups, from weak to moderate (r -0.01 to -0.46). Low hallux mobility was significantly related to higher center of pressure values in older people. [Conclusion] These results have clinical implications for balance and foot posture assessments.

Relationship between force platform and two functional tests for measuring balance in the elderly / Relação entre plataforma de força e dois testes funcionais para medidas de equilíbrio em idosos

BACKGROUND: Clinical and laboratory methods have been developed to assess the different dimensions of postural control with the aim to increase the clinical relevance of decisions about balance deficit. Objectives: The purpose of this study was to correlate the force platform measurements with two functional tests used to evaluate balance in elderly. METHODS: A total of 124 physically independent elderly volunteers participated in this study. Subjects performed the following three tests: 1) a traditional functional balance test, named the one-leg standing test, which measures the time in seconds at this position; 2) a functionalagility/dynamic balance test, which quantifies the total time in seconds that a subject canstand up from a chair and move as quickly as possible around two cones; and 3) an unipodal balance test on a force platform. RESULTS: The one-leg standing test yielded a mean of 12 seconds (SD=9 s), while the mean time observed in the functional agility/dynamic balance test was 26 seconds (SD=6 s). The correlations between the balance parameters of force platform and two functional tests varied between -0.28 and 0.20, which shows a weak association between them. CONCLUSIONS: Our results support the idea that these functional tests do not necessarily furnish the same information regarding balance mechanisms as the force platform. This study contributes to the evaluation of balance in elderly and suggests that functional tests should be used with caution especially in regards to the purposes of the research and when conducting clinical assessments of the elderly.

CONTEXTUALIZAÇÃO: Diferentes métodos clínicos e laboratoriais têm sido desenvolvidos para avaliar as dimensões do controle postural a fim de aumentar a relevância clínica nas decisões quanto ao déficit de equilíbrio. Objetivos: Correlacionar as medidas de plataforma de força com dois testes funcionais usados para avaliar o equilíbrio em idosos. MÉTODOS: Cento e vinte e quatro idosos fisicamente independentes e voluntários participaram deste estudo. Os sujeitos realizaram três testes: 1) teste tradicional e funcional de equilíbrio estático, que mede o tempo-limite em segundos de apoio unipodal; 2) teste funcional de agilidade e equilíbrio dinâmico, que quantifica o tempo total em segundos para realizar uma tarefa de sentar, levantar e locomover-se o mais rápido possível em torno de dois cones e 3) teste de equilíbrio unipodal sobre uma plataforma de força. RESULTADOS: A média do tempo-limite para o teste funcional de equilíbrio estático foi de 12 segundos (DP=9s), enquanto a média de tempo para o teste funcional de agilidade e equilíbrio dinâmico foi de 26 segundos (DP=6s). As correlações entre os parâmetros de equilíbrio da plataforma de força e os testes funcionais variaram entre -0,28 e 0,20, sugerindo uma associação fraca entre eles. CONCLUSÕES: Os resultados suportam a ideia de que os dois testes funcionais não fornecem, necessariamente, a mesma informação que uma plataforma fornece quanto aos mecanismos de controle postural para equilíbrio. Este estudo colabora para a avaliação do equilíbrio em idosos e sugere que alguns testes funcionais deveriam ser usados com mais cautela quanto à sua indicação no alcance dos objetivos da pesquisa e na identificação dos possíveis déficits de equilíbrio, especialmente quando usados para avaliação clínica de idosos.

Relationship between force platform and two functional tests for measuring balance in the elderly.

BACKGROUND: Clinical and laboratory methods have been developed to assess the different dimensions of postural control with the aim to increase the clinical relevance of decisions about balance deficit. OBJECTIVES: The purpose of this study was to correlate the force platform measurements with two functional tests used to evaluate balance in elderly. METHODS: A total of 124 physically independent elderly volunteers participated in this study. Subjects performed the following three tests: 1) a traditional functional balance test, named the one-leg standing test, which measures the time in seconds at this position; 2) a functional agility/dynamic balance test, which quantifies the total time in seconds that a subject can stand up from a chair and move as quickly as possible around two cones; and 3) an unipodal balance test on a force platform. RESULTS: The one-leg standing test yielded a mean of 12 seconds (SD=9 s), while the mean time observed in the functional agility/dynamic balance test was 26 seconds (SD=6 s). The correlations between the balance parameters of force platform and two functional tests varied between -0.28 and 0.20, which shows a weak association between them. CONCLUSIONS: Our results support the idea that these functional tests do not necessarily furnish the same information regarding balance mechanisms as the force platform. This study contributes to the evaluation of balance in elderly and suggests that functional tests should be used with caution especially in regards to the purposes of the research and when conducting clinical assessments of the elderly.

Schistosomicidal activity of the essential oil of Ageratum conyzoides L. (Asteraceae) against adult Schistosoma mansoni worms.

The in vitro schistosomicidal effects of the essential oil of Ageratum conyzoides L. (Ac-EO) against adult worms of Schistosoma mansoni is reported in this paper. Concerning this activity, Ac-EO was considered to be active, but less effective than the positive control (praziquantel, PZQ) in terms of separation of coupled pairs, mortality, decrease in motor activity, and tegumental alterations. However, Ac-EO caused an interesting dose-dependent reduction in the number of eggs of S. mansoni. Precocene I (74.30%) and (E)-caryophyllene (14.23%) were identified as the two major constituents of Ac-EO. These compounds were tested individually and were found to be much less effective than Ac-EO and PZQ. A mixture of the two major compounds in a ratio similar to that found in the Ac-EO was also less effective than Ac-EO, thus revealing that there are no synergistic effects between these components. These results suggest that the essential oil of A. conyzoides is very promising for the development of new schistosomicidal agents.

Screening of filamentous fungi to identify biocatalysts for lupeol biotransformation.

The goal of the study was to evaluate the ability of filamentous fungi to biotransform the pentacyclic triterpene lupeol. The microbial transformations were carried out in shake flasks in different media. Experiments were also run with control flasks. Samples of each culture were taken every 24 hours, extracted with ethyl acetate, and analyzed by GC-MS. The biotransformation of lupeol by Aspergillus ochraceus and Mucor rouxii afforded two compounds in each culture, which were detected in the cultures developed for more than seven days only in the Koch's K1 medium. The obtained data demonstrated that A. ochraceus is a good biocatalyst to introduce double bonds in the lupeol structure, whereas M. rouxii exhibits ability to biocatalyze oxygen insertions in that pentacyclic triterpene. Mass spectrometry was demonstrated to be an efficient analytical method to select promising biocatalysts for the compound investigated in this study. The biotransformation processes were influenced by the culture medium and incubation period. The obtained results open the perspective of using A. ochraceus and M. rouxii in pentacyclic triterpene biotransformations.

The N-glycanase png-1 acts to limit axon branching during organ formation in Caenorhabditis elegans.

Peptide:N-glycanases (PNGases) are cytoplasmic de-N-glycosylation enzymes that have been shown in cultured cells to facilitate the degradation of misfolded glycoproteins during endoplasmic reticulum-associated degradation and in the processing of major histocompatibility complex class I antigens for proper cell-surface presentation. The gene encoding PNGase activity was initially described in budding yeast (Png1p) and shown to be highly conserved from yeast to humans, but physiological roles in higher organisms have not been elucidated. Here we describe peripheral nervous system defects associated with the first loss-of-function mutations in an animal PNGase. Mutations in png-1, the Caenorhabditis elegans PNGase ortholog, result in an increase in axon branching during morphogenesis of the vulval egg-laying organ and egg-laying behavior changes. Neuronal defects include an increase in the branched morphology of the VC4 and VC5 egg-laying neurons as well as inappropriate branches from axons that run adjacent to the vulva but would normally remain unbranched. We show that png-1 is widely expressed and can act from both neurons and epithelial cells to restrict axon branching. A deletion allele of the DNA repair gene rad-23, orthologs of which are known to physically interact with PNGases in yeast and mammals, displays similar axon branching defects and genetic interactions with png-1. In summary, our analysis reveals a novel developmental role for a PNGase and Rad-23 in the regulation of neuronal branching during organ innervation.

Three N2-benzoyloxybenzamidines: sheet structures built from hard and soft hydrogen bonds and aromatic pi-pi stacking interactions.

Molecules of the title compounds N(2)-(benzoyloxy)benzamidine, C(14)H(12)N(2)O(2), (I), N(2)-(2-hydroxybenzoyloxy)benzamidine, C(14)H(12)N(2)O(3), (II), and N(2)-benzoyloxy-2-hydroxybenzamidine, C(14)H(12)N(2)O(3), (III), all have extended chain conformations, with the aryl groups remote from one another. In (I), the molecules are linked into chains by a single N-H...N hydrogen bond [H...N = 2.15 A, N...N = 3.029 (2) A and N-H...N = 153 degrees ] and these chains are linked into sheets by means of aromatic pi-pi stacking interactions. There is one intramolecular O-H...O hydrogen bond in (II), and a combination of one three-centre N-H...(N,O) hydrogen bond [H...N = 2.46 A, H.O = 2.31 A, N...N = 3.190 (2) A, N...O = 3.146 (2) A, N-H...N = 138 degrees and N-H...O = 154 degrees ] and one two-centre C-H...O hydrogen bond [H.O = 2.46 A, C...O = 3.405 (2) A and C-H...O = 173 degrees ] links the molecules into sheets. In (III), an intramolecular O-H...N hydrogen bond and two N-H...O hydrogen bonds [H...O = 2.26 and 2.10 A, N...O = 2.975 (2) and 2.954 (2) A, and N-H...O = 138 and 163 degrees ] link the molecules into sheets.