Serum amino acid profiles in patients with mild cognitive impairment and in patients with mild dementia or moderate dementia

Study of metabolite differences of flue-cured tobacco from Canada (CT157) and Yunnan (Yunyan 87)

In order to comprehend the dissimilarities in tobacco quality between Canada and Yunnan, a comparison of the aroma components was conducted using GC-MS and HPLC analysis, coupled with orthogonal partial least squares discriminant analysis (OPLS-DA). The study revealed the detection of a total of 81 aroma components and 22 non-volatile components in both varieties of tobacco leaves. Specifically, there were 102 components of Canada tobacco leaves and 103 components of Yunnan tobacco leaves. Subsequently, a screening was performed on these two types of tobacco leaves, identifying 51 differential components, which accounted for approximately 49.5 % of the overall components detected. Among these, Canada tobacco exhibited a higher concentration of 22 components, comprising roughly 36.4 % of the total, which were primarily composed of semi-volatile organic acids and sesquiterpenes. On the other hand, Yunnan tobacco was characterized by a comparatively higher content of 43 components, constituting approximately 63.6 %, including fatty acid esters, phenols, diterpenes, sugars, and amino acids. Comparatively, Canada tobacco demonstrated elevated levels of fatty acids and sesquiterpenes, while the content of fatty acid esters and diterpenes was relatively lower. These distinctions in aroma components potentially contribute to the varied sensory aroma profiles exhibited by the two types of tobacco.

Current Understanding of Giardia lamblia and Pathogenesis of Stunting and Cognitive Deficits in Children from Low- and Middle-Income Countries

Purpose of Review

Giardia lamblia is a common intestinal parasite worldwide, mainly in children from low- and middle-income countries (LMIC). Also, it has been associated with increased intestinal permeability, stunting, and cognitive impairment. Nonetheless, the pathogenesis of long-term consequences is difficult to elucidate.

Recent Findings

Recent studies try to understand the long-term consequences of Giardia infections. First, well-characterized studies associate Giardia with intestinal damage and child growth. Second, infections appear not to be associated with inflammation, but "lack of inflammation" may not, however, entirely exclude a pro-inflammatory pathway. Finally, some important amino acids are lower and could contribute to prolongate stunting and cognitive deficit.

Summary

Giardia infections in LMIC used to be associated with child growth shortfalls, gut permeability, and cognitive deficits. Multifactorial effects could be associated with Giardia, including nutritional, altered microbiota, and generation of potentially toxic microbial metabolic byproducts, all together increasing risk of long-term outcomes.

Genetic Insights into the Association and Causality Between Blood Metabolites and Alzheimer's Disease

Background

Alzheimer's disease (AD) is an increasing public health concern with the aging of the global population. Understanding the genetic correlation and potential causal relationships between blood metabolites and AD may provide important insights into the metabolic dysregulation underlying this neurodegenerative disorder.

Objective

The aim of this study was to investigate the causal relationship between blood metabolites and AD using Mendelian randomization (MR) analysis.

Methods

Association data were obtained from three large-scale genome-wide association studies of 486 blood metabolites (N = 7,824), AD (71,880 cases and 383,378 controls), early-onset AD (N = 303,760), and late-onset AD (N = 307,112). Causal associations between blood metabolites and AD were assessed using inverse variance weighting (IVW), MR-Egger, and weighted median methods. Bidirectional two-sample MR analysis was used to identify causal blood metabolites. MR-PRESSO, MR-Egger, and Cochran-Q were used to quantify instrumental variable heterogeneity and horizontal pleiotropy.

Results

Using MR and sensitivity analysis, we identified 40 blood metabolites with potential causal associations with AD. After applying false discovery rate (FDR) correction, two metabolites, gamma-glutamylphenylalanine (OR = 1.15, 95% CI: 1.06-1.24, p = 3.88×10-4, q = 0.09) and X-11317 (OR = 1.16, 95% CI: 1.08-1.26, p = 1.14×10-4, q = 0.05), retained significant associations with AD. Reverse MR analysis indicated no significant causal effect of AD on blood metabolites. No significant instrumental variable heterogeneity or horizontal pleiotropy was found.

Conclusions

This two-sample MR study provides compelling evidence for a potential causal relationship between blood metabolic dysregulation and susceptibility to AD. Further investigation of the biological relevance of the identified metabolites to AD and additional supporting evidence is warranted.

Cerebrospinal Fluid Amino Acid Metabolite Signatures of Diabetic Cognitive Dysfunction Based on Targeted Mass Spectrometry

BACKGROUND

Diabetic cognitive dysfunction (DCD) is one of severe diabetic complications and might develop to irreversible dementia. Early diagnosis and detection of DCD is significant for prevention and treatment.

OBJECTIVE

The main objective of this study was to investigate the amino acid profiles of rat with DCD in the cerebrospinal fluid (CSF) to distinguish the early specific biomarkers.

METHODS

In total, rats were assigned into control and model groups. Model was induced by intraperitoneal injection of streptozotocin. The Morris water maze (MWM) method was used to evaluate learning and memory in rats on the 13th week after the model established. CSF samples were collected via cisterna magna puncture at the 0th, 5th, 9th, and 13th week, and amino acids profiling of CSF samples were performed via ultra performance liquid chromatography multiple reaction monitoring mass spectrometry (UPLC-MRM-MS). The amino acid profile was processed through multivariate analysis to identify potential biomarkers, and the related metabolic pathways were analyzed by MetaboAnalyst 5.0.

RESULTS

Compared to the control group, the escape latency of the MWM was significantly prolonged in model group rats (p <  0.05). Different amino acid profiles were obtained between two groups. L-Alanine, L-Glutamine, L-Lysine, L-Serine, and L-Threonine were identified as potential biomarkers for DCD. These biomarkers are principally involved in glycine, serine, and threonine metabolism, aminoacyl-tRNA biosynthesis, alanine, aspartate, and glutamate metabolism, and glyoxylate and dicarboxylate metabolism.

CONCLUSION

There are amino acid biomarkers in the CSF of rat with DCD. The mechanism of DCD is related to those pathways, which provide help for the early diagnosis and treatment and mechanism research.