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Enhanced In Situ Bioremediation (EISB) using Emulsified Vegetable Oil (EVO) as a long-term electron donor has gained prominence for the treatment of groundwater contaminated with chlorinated ethenes (CEs). This study explores the potential of isotopic and molecular biology tools (MBT) to investigate the CEs (PCE, TCE and cis-DCE) bioremediation using EVO in a contaminated site. A multiple approach using C and Cl-CSIA, quantification of Dehalococcoides (Dhc) and specific reductive dechlorination (RD) gene population, and hydrochemical data in microcosm experiments and field samples was applied. Despite the high partitioning of CEs into the EVO phase, the carbon isotopic values of the remaining CEs fraction in the aqueous phase did not exhibit significant changes caused by phase partitioning in laboratory experiments. Both microcosm experiments and field data revealed a rapid RD of PCE and TCE, resulting in the transient accumulation of cis-DCE, which was slowly degraded to vinyl chloride (VC). These results agreed with the presence of Dhc populations and a shift to stronger reducing conditions in the field: i) RD functional genes (tceA, vcrA and bvcA) exhibited a trend to higher values and ii) a substantial increase in Dhc populations (up to 30% of the total bacterial populations) was observed over time. The dual-element isotope slope ΛC-Cl for RD of cis-DCE obtained from field data (ΛC - Cl = 5 ± 3) was similar to the one determined from the microcosm experiments under controlled anoxic conditions (ΛC - Cl = 4.9 ± 0.8). However, ΛC-Cl values differ from those reported so far for laboratory studies with Dhc strains and mixed cultures containing Dhc, i.e., between 8.3 and 17.8. This observation underscores the potential variety of reductive dehalogenases involved during cis-DCE RD and the importance of determining site-specific Λ and É values in order to improve the identification and quantification of transformation processes in the field.
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Background: The "Triana Test" is a novel story recall test based on emotional material with demonstrated accuracy in diagnosing mild cognitive impairment patients. Objective: This study aims to obtain normative data for the "Triana Test". Methods: A normative study was conducted at a university hospital in Spain. Partners of patients were systematically recruited if eligible (age ≥50, no memory complaints, and a total TMA-93 score at or above the 10th percentile). The "Triana Test" was administered and scored. For developing the normative data, a regression-based method was followed. Results: The final sample included 362 participants (median ageâ=â66, rangeâ=â50-88; 64.9% females). A model including age and educational level better predicted the total scores. Combinations of these variables resulted in different 10th percentile scores. Conclusions: Norms for using the "Triana Test" are now available. The provided cutoffs for the 10th percentile will aid in the diagnosis of prodromal Alzheimer's disease.
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BACKGROUND: TMA-93 examines relational binding using images. Biomarker validation has demonstrated that it is discriminative for diagnosing early AD. The effect of cognitive reserve on TMA-93 performance remains unexplored and could improve the interpretative framework for using the test. OBJECTIVE: To study the effect of cognitive reserve on TMA-93 performance and to provide new norms for the test that include its measurement. METHODS: Cognitively unimpaired people aged 55 and over were systematically recruited for this cross-sectional normative study in southern Spain. Age, sex, and scores on the Cognitive Reserve Questionnaire (CRQ; maximum score: 25 points) were collected, and the TMA-93 was administered (maximum score: 30 points). Percentile-based reference data that captured combinations of socio-demographics variables with significant effect on TMA-93 performance were calculated. RESULTS: 902 participants (62.5% female; age: medianâ=â68, IQRâ=â61-75, rangeâ=â55-90) were included. CRQ total scores were globally low (medianâ=â8, IQRâ=â5-13, rangeâ=â0-24). Cognitive reserve, including modifiable items as reading activity and intellectual gaming activity, and age mainly supported the TMA-93 total score variance. Sex seemed to have some influence in the elderly. TMA-93 total scores medians began to drop from 70-75 years old. Higher total score on the CRQ and, possibly, female sex determined a gentler slope. New norms based on these variables showed wide variations in scores for the 5th and 10th percentiles. CONCLUSION: Visual relational binding ability depends on cognitive reserve, including modifiable items. The age-related binding deficit is buffered by higher cognitive reserve and, at older ages, by female sex.
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Disfunción Cognitiva , Reserva Cognitiva , Anciano , Humanos , Femenino , Masculino , Pruebas Neuropsicológicas , Estudios Transversales , Lectura , Encuestas y Cuestionarios , Disfunción Cognitiva/diagnósticoRESUMEN
BACKGROUND: TMA-93 examines relational binding using images. The test has been proven to be discriminative for diagnosing early Alzheimer's disease by biomarkers. Norms for this test are available, but the elderly, at high risk for Alzheimer's disease, have not yet been widely represented. OBJECTIVE: To extend normative data on the TMA-93 for people aged 75 and over. METHODS: An extension of the Spanish TMA-93 normative study was undertaken. Only cognitively unimpaired people aged 75 and over were included. Age, gender, and educational attainment were registered as socio-demographic variables. Using histograms analysis, median comparisons, and linear regression analysis, we selected variables that demonstrated influence on TMA-93 total scores and provided percentile-base reference data according to combinations of those variables. RESULTS: We included 431 new participants, resulting in a total sample of 657 individuals (median ageâ=â78, interquartile rangeâ=â76-81, rangeâ=â75-93). Percentile-base reference data stratified by a combination of age ranges (75-79, nâ=â428; and ≥80 years, nâ=â229), and educational attainment (<âfirst grade, nâ=â253; first grade, nâ=â209; >âfirst grade, nâ=â195) revealed that participants achieved a minimum TMA-93 total score of 26/30 at the 50th-percentile regardless of stratum. At the 10th-percentile, a maximum of 24/30 was achieved in the more educated stratum contrasting with a minimum of 19/30 in the less educated stratum. CONCLUSION: Although mitigated by lower levels of education, performance on the TMA-93 is widely preserved in cognitively unimpaired people aged 75 and over. The test could facilitate the screening of elderly patients with memory complaints.
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Enfermedad de Alzheimer , Anciano , Enfermedad de Alzheimer/diagnóstico por imagen , Escolaridad , Humanos , Modelos Lineales , Tamizaje Masivo , Pruebas Neuropsicológicas , Valores de ReferenciaRESUMEN
Metabolites produced by an altered gut microbiota might mediate the effects in the brain. Among metabolites, the fecal volatile organic compounds (VOCs) are considered to be potential biomarkers. In this study, we examined both the VOCs and bacterial taxa in the feces from healthy subjects and Alzheimer's disease (AD) patients at early and middle stages. Remarkably, 29 fecal VOCs and 13 bacterial genera were differentiated from the healthy subjects and the AD patients. In general, higher amounts of acids and esters were found in in the feces of the AD patients and terpenes, sulfur compounds and aldehydes in the healthy subjects. At the early stage of AD, the most relevant VOCs with a higher abundance were short-chain fatty acids and their producing bacteria, Faecalibacterium and Lachnoclostridium. Coinciding with the development of dementia in the AD patients, parallel rises of heptanoic acid and Peptococcus were observed. At a more advanced stage of AD, the microbiota and volatiles shifted towards a profile in the feces with increases in hexanoic acid, Ruminococcus and Blautia. The most remarkable VOCs that were associated with the healthy subjects were 4-ethyl-phenol and dodecanol, together with their possible producers Clostridium and Coprococcus. Our results revealed a VOCs and microbiota crosstalk in AD development and their profiles in the feces were specific depending on the stage of AD. Additionally, some of the most significant fecal VOCs identified in our study could be used as potential biomarkers for the initiation and progression of AD.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Microbiota , Compuestos Orgánicos Volátiles , Humanos , Compuestos Orgánicos Volátiles/metabolismo , Enfermedad de Alzheimer/metabolismo , Disfunción Cognitiva/microbiología , Heces/microbiología , Ácidos Grasos Volátiles/metabolismo , Bacterias/metabolismo , Biomarcadores/metabolismoRESUMEN
OBJECTIVE: To first validate the diagnostic accuracy of the "Triana Test," a new story recall test based on emotional material. METHOD: A phase I study of validation. We included 55 patients with amnestic Mild Cognitive Impairment and 69 healthy controls, diagnosed according to the "Memory Associative Test of the district of Seine-Saint-Denis" (TMA-93), and matched by age, gender, and educational level. The Triana Test's diagnostic accuracy was calculated by ROC curve analysis and Spearman correlations estimated its convergent validity with a hippocampal memory test, the Free and Cued Selective Reminding Test with Immediate Recall (FCSRT+IR). RESULTS: The "Triana Test" immediate and delayed recalls showed adequate diagnostic accuracy (AUC ≥ 0,74). The delayed free recall showed the highest diagnostic accuracy (AUC = 0.86). Correlations with the FCSRT+IR were moderate to strong. CONCLUSIONS: The "Triana Test" demonstrated accuracy for discriminating amnestic Mild Cognitive Impairment patients from healthy controls and convergent validity with the FCSRT+IR.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Disfunción Cognitiva/diagnóstico , Señales (Psicología) , Humanos , Recuerdo Mental , Pruebas NeuropsicológicasRESUMEN
BACKGROUND: The Memory Associative Test TMA-93 examines visual relational binding, characteristically affected in early-AD stages. OBJECTIVE: We aim to validate the TMA-93 by biomarkers determination and compare its diagnostic characteristics with the Free and Cued Selective Reminding Test (FCSRT). METHODS: Retrospective analysis of a Biobank database. Patients' records initially consulted for memory complaints, scored MMSE≥22, had TMA-93 and FCSRT tested, and AD biomarker determination (Amyloid-PET or CSF), either positive or negative, were selected. As cutoffs, we considered the 10-percentile for TMA-93 (P10/TMA-93), and "total free recall" (TFR) 21/22, total recall (TR) 43/44, and Cued Index <â0.77 for FCSRT from previous Spanish validation and normative studies. Diagnostic utilities were calculated using ROC curves and compared by the DeLong method. We studied if one test improved the other test's prediction, following a forward stepwise logistic regression model. RESULTS: We selected 105 records: 64 "positive" and 41 "negative" biomarkers. TMA-93 total score diagnostic utility (AUCâ=â0.72; 95%CI:0.62-0.82) was higher than those of the FCSRT: TFR (AUCâ=â0.70; 95%CI: 0.60-0.80), TR (AUCâ=â0.63; 95%CI:0.53-0.74), and Cued Index (AUCâ=â0.62; 95%CI:0.52-0.73). The P10/TMA-93 cutoff showed 86%sensitivity, similar to that of the most sensitive FCSRT cutoff (TFR21/22, 89%) and 29%specificity, lower than that of the most specific FCSRT cutoff (Cued Indexâ<â0.77, 57%). 32.8%of the positive-biomarker group scored above CI/0.77 but below p10TMA-93. The addition of TMA-93 total score to FCSRT variables improved significantly the biomarkers results' prediction. CONCLUSION: TMA-93 demonstrated "reasonable" diagnostic utility, similar to FCSRT, for discriminating AD biomarker groups. TMA-93 total score improved the AD biomarker result prediction when added to FCSRT variables.
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Enfermedad de Alzheimer/diagnóstico , Pruebas Neuropsicológicas , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/fisiopatología , Enfermedad de Alzheimer/psicología , Péptidos beta-Amiloides/líquido cefalorraquídeo , Péptidos beta-Amiloides/metabolismo , Biomarcadores , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Femenino , Humanos , Masculino , Pruebas de Estado Mental y Demencia , Persona de Mediana Edad , Fragmentos de Péptidos/líquido cefalorraquídeo , Tomografía de Emisión de Positrones , Estudios Retrospectivos , Proteínas tau/líquido cefalorraquídeoRESUMEN
BACKGROUND: Memory tests focused on binding may be more sensitive to diagnose Alzheimer's disease (AD) at an early phase. TMA-93 examines relational binding by images. OBJECTIVE: Evaluate the reliability (internal consistency and inter-rater and test-retest reliability) and feasibility of the TMA-93 in a clinic setting with low-educated individuals and limited face-to-face time per patient. METHODS: The study was undertaken in a neurology outpatient clinic of a hospital in Southern Spain. The internal consistency of the TMA-93 was estimated in 35 patients with amnestic mild cognitive impairment (aMCI) and 40 healthy controls (HCs). The inter-rater reliability (by two raters) and feasibility (by recording the percentage of participants who completed the test, and by timing the administration time) were evaluated in HCs (nâ=â16), aMCI patients (nâ=â18), and mild dementia patients (nâ=â15). The test-retest reliability for the TMA-93 total score was studied in 51 HCs tested by the same examiner 2-4 months apart. The internal consistency was estimated by Cronbach's alpha. The inter-rater and test-retest reliability was quantified by the intraclass correlation coefficient (ICC). The administration time was compared by diagnosis. RESULTS: The internal consistency was "optimal" (Cronbach's alphaâ=â0.936). The test-retest reliability was "good" [ICCâ=â0.802 (CI 95% â=â0.653-0.887)]. The inter-rater reliability was "optimal" [ICCâ=â0.999, (CI 95% â=â0.999-1)]. All participants completed the test. The administration time ranged from less than 3âmin in HCs to 6âmin in aMCI patients, and 7âmin in mild dementia patients. CONCLUSION: Good feasibility and reliability support using the TMA-93 for examining visual relational binding, particularly in the context of low-educational attainment and limited time per patient.
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BACKGROUND: TMA-93 examines binding by images, a potential advantage for less-educated individuals. OBJECTIVE: To obtain norms from older Spanish adults for TMA-93. METHODS: A cross-sectional normative study was undertaken in a general neurology outpatient clinic of a university hospital in the Southern Spanish region of Andalusia. Partners of patients who attended the clinic were systematically recruited when eligible: aged 50 and over, no memory complaints, and a total score equal or above percentile 10 on Phototest. Age, gender, and educational attainment were considered as sociodemographic variables. TMA-93 was administered and the total score was registered. RESULTS: The final sample contained 1,131 participants (mean ageâ=â65.7, SDâ=â9.2), including 305 individuals (27%) who did not completed primary studies. The total score on TMA-93 showed a non-normal, left asymmetric, and leptokurtic distribution (medianâ=â29, interquartile rangeâ=â27-30, rangeâ=â16-30) mitigated by lower education and older age. Stratified analysis by age and education showed wide variations of the scores for the 5-percentile. CONCLUSION: TMA-93 runs with a ceiling effect in non-cognitively impaired older Spanish adults. The score for the 5-percentile depends on age and education. The test is feasible for low-educated individuals.