Association between the risk and severity of Parkinson's disease and plasma homocysteine, vitamin B12 and folate levels: a systematic review and meta-analysis.

Background: Parkinson's disease (PD) is recognized as the second most prevalent progressive neurodegenerative disease among the elderly. However, the relationship between PD and plasma homocysteine (Hcy), vitamin B12, and folate has yielded inconsistent results in previous studies. Hence, in order to address this ambiguity, we conducted a meta-analysis to summarize the existing evidence. Methods: Suitable studies published prior to May 2023 were identified by searching PubMed, EMBASE, Medline, Ovid, and Web of Science. The methodological quality of eligible studies was assessed using the Newcastle-Ottawa Quality Assessment Scale (NOS). Meta-analysis and publication bias were then performed using R version 4.3.1. Results: The results of our meta-analysis, consisting of case-control and cross-sectional studies, showed that PD patients had lower folate and vitamin B12 levels (SMD [95%CI]: -0.30[-0.39, -0.22], p < 0.001 for Vitamin B12; SMD [95%CI]: -0.20 [-0.28, -0.13], p < 0.001 for folate), but a significant higher Hcy level (SMD [95%CI]: 0.86 [0.59, 1.14], p < 0.001) than healthy people. Meanwhile, PD was significantly related to hyperhomocysteinemia (SMD [95%]: 2.02 [1.26, 2.78], p < 0.001) rather than plasma Hcy below 15 µmol/L (SMD [95%]: -0.31 [-0.62, 0.00], p = 0.05). Subgroup analysis revealed associations between the Hcy level of PD patients and region (p = 0.03), age (p = 0.03), levodopa therapy (p = 0.03), Hoehn and Yahr stage (p < 0.001), and cognitive impairment (p < 0.001). However, gender (p = 0.38) and sample size (p = 0.49) were not associated. Conclusion: Hcy, vitamin B12, and folic acid potentially predict the onset and development of PD. Additionally, multiple factors were linked to Hcy levels in PD patients. Further studies are needed to comprehend their roles in PD.

Criteria for judging the immune markers of COVID-19 disease vaccines.

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sweeping the world, effective and affordable vaccines are in urgent need. A reliable system for the assessment of SARS-CoV-2 vaccines would boost the development of vaccines and reduce the research cost. We constructed a logistic regression model and analyzed the relationship between antibody (Ab) level and efficacy of different vaccine types. The relationship between assessment dates and Ab levels was depicted by plotting the mean of Ab levels evolved over time and a fitted cubic polynomial model. Anti-spike immunoglobulin G (IgG) could best estimate the vaccine efficacy (VE) (adjusted R 2  = 0.731) and neutralizing Ab to live SARS-CoV-2 also explained a fine relationship (adjusted R 2 = 0.577). Neutralizing Abs to live SARS-CoV-2 in inactivated virus vaccines reached a peak during days 40-60, and their receptor-binding domain (RBD)-IgG peaked during days 40-50. For messenger RNA (mRNA) and viral vector vaccines, their neutralizing Ab to live SARS-CoV-2 peaked later than day 40, and for RBD-IgG during days 30-50. For mRNA and viral vector vaccines, their peak time of Abs was later than that in inactivated virus vaccines. RBD-IgG peaked earlier than Ab to live SARS-CoV-2. Anti-spike IgG and Ab to live SARS-CoV-2 may be good immune markers for VE assessment.

Targeting Myeloid-Derived Suppressor Cells Derived From Surgical Stress: The Key to Prevent Post-surgical Metastasis.

Myeloid-derived suppressor cells (MDSCs) are known to play an essential part in tumor progression under chronic stress settings through their manipulation of adaptive and innate immune systems. Previous researches mainly focus on MDSC's role in the chronic tumor immune environment. In addition, surgery can also serve as a form of acute stress within the patient's internal environment. Nevertheless, the part that MDSCs play in post-surgical tumor development has not gained enough attention yet. Although surgery is known to be an effective definite treatment for most localized solid tumors, there are still plenty of cancer patients who experience recurrence or metastasis after radical resection of the primary tumor. It is believed that surgery has the paradoxical capability to enhance tumor growth. Many possible mechanisms exist for explaining post-surgical metastasis. We hypothesize that surgical resection of the primary tumor can also facilitate the expansion of MDSCs and their pro-tumor role since these surgery-induced MDSCs can prepare the pre-metastatic niche (the "soil") and at the same time interact with circulating tumor cells (the "seeds"). This vicious, reciprocal mechanism is a crucial point in the emergence of post-surgical metastasis. According to our hypothesis, MDSCs can be the precise target to prevent cancer patients from post-surgical recurrence and metastasis during the perioperative phase to break the wretched cycle and provide better long-term survival for these patients. Future studies are needed to validate this hypothesis.