Optimal cutoff scores of the Montreal Cognitive Assessment to detect mild cognitive impairment and dementia in Costa Rican older adults.

BACKGROUND: The burden of Alzheimer's disease and related dementias (AD/ADRD) in Costa Rica is expected to become one of the highest in the region. Early detection will help optimize resources and improve primary care interventions. The Montreal Cognitive Assessment (MoCA) has shown good sensitivity for detecting mild cognitive impairment (MCI), but specificity varies depending on the population. This motivated the analysis of different cutoffs to minimize false-positive classifications in a Costa Rican sample for its use in clinical settings. METHODS: Data was analyzed from 516 memory clinic outpatients (148 cognitively normal, 260 MCI, 108 mild AD/ADRD; mean age 66.3 ± 10.8 years) who underwent complete neurological and neuropsychological assessment and were diagnosed by consensus. Optimal MoCA cutoff scores were identified using a multiple cutoff approach. RESULTS: Overall, a cutoff score of ≥ 23 showed better accuracy to distinguish between normal cognition (NC) and MCI (sensitivity 73%, specificity 83%). When analyzed by educational levels, a cutoff score of ≥ 21 showed better accuracy for ≤ 6 years (sensitivity 80%, specificity 76%), ≥23 for 7-12 years (sensitivity 86%, specificity 76%) and ≥ 24 for > 12 years (sensitivity 70%, specificity 85%). For distinguishing MCI from mild AD/ADRD, the optimal overall cutoff score was ≥ 15 (sensitivity 66%, specificity 85%). When stratified by years of education, cutoff scores of ≥ 14 showed better accuracy for ≤ 6 years (sensitivity 70%, specificity 88%), ≥15 for 7-12 years (sensitivity 46%, specificity 95%) and ≥ 17 for > 12 years (sensitivity 67%, specificity 93%). CONCLUSIONS: A MoCA cutoff score of ≥ 23 in the Costa Rican population showed better diagnostic accuracy for detecting MCI and may reduce the false positive rate. Our findings may be helpful for primary care clinical settings and further referral criteria.

Porcine Fetal-Derived Fibroblasts Alter Gene Expression and Mitochondria to Compensate for Hypoxic Stress During Culture.

The Warburg effect is characterized by decreased mitochondrial oxidative phosphorylation and increased glycolytic flux in adequate oxygen. The preimplantation embryo has been described to have characteristics of the Warburg effect, including similar changes in gene expression and mitochondria, which are more rudimentary in appearance. We hypothesized hypoxia would facilitate anaerobic glycolysis in fibroblasts thereby promoting gene expression and media metabolite production reflecting the Warburg effect hallmarks in early embryos. Additionally, we speculated that hypoxia would induce a rudimentary small mitochondrial phenotype observed in several cell types evidenced to demonstrate the Warburg effect. While many have examined the role hypoxia plays in pathological conditions, few studies have investigated changes in primary cells which could be used in somatic cell nuclear transfer. We found that cells grown in 1.25% O2 had normal cell viability and more, but smaller mitochondria. Several hypoxia-inducible genes were identified, including seven genes for glycolytic enzymes. In conditioned media from hypoxic cells, the quantities of gluconolactone, cytosine, and uric acid were decreased indicating higher consumption than control cells. These results indicate that fibroblasts alter gene expression and mitochondria to compensate for hypoxic stress and maintain viability. Furthermore, the metabolic changes observed, making them more similar to preimplantation embryos, could be facilitating nuclear reprogramming making these cells more amendable to future use in somatic cell nuclear transfer.

Pharmacologic Reprogramming Designed to Induce a Warburg Effect in Porcine Fetal Fibroblasts Alters Gene Expression and Quantities of Metabolites from Conditioned Media Without Increased Cell Proliferation.

The Warburg effect is a metabolic phenomenon characterized by increased glycolytic activity, decreased mitochondrial oxidative phosphorylation, and the production of lactate. This metabolic phenotype is characterized in rapidly proliferative cell types such as cancerous cells and embryonic stem cells. We hypothesized that a Warburg-like metabolism could be achieved in other cell types by treatment with pharmacological agents, which might, in turn, facilitate nuclear reprogramming. The aim of this study was to treat fibroblasts with CPI-613 and PS48 to induce a Warburg-like metabolic state. We demonstrate that treatment with both drugs altered the expression of 69 genes and changed the level of 21 metabolites in conditioned culture media, but did not induce higher proliferation compared to the control treatment. These results support a role for the reverse Warburg effect, whereby cancer cells induce cancer-associated fibroblast cells in the surrounding stroma to exhibit the metabolically characterized Warburg effect. Cancer-associated fibroblasts then produce and secrete metabolites such as pyruvate to supply the cancerous cells, thereby supporting tumor growth and metastasis. While anticipating an increase in the production of lactate and increased cellular proliferation, both hallmarks of the Warburg effect, we instead observed increased secretion of pyruvate without changes in proliferation.