Experimental Biology and Medicine最新文献

Safety concerns about general anesthetics (GA), such as desflurane (a commonly used gaseous anesthetic agent), arose from studies documenting neural cell death and behavioral changes after early-life exposure to anesthetics and compounds with related modes of action. Neural stem cells (NSCs) can recapitulate most critical events during central nervous system (CNS) development in vivo and, therefore, represent a valuable in vitro model for evaluating potential desflurane-induced developmental neurotoxicity. In this study, NSCs harvested from the hippocampus of a gestational day 80 monkey brain were applied to explore the temporal relationships between desflurane exposures and neural stem cell health, proliferation, differentiation, and viability. At clinically relevant doses (5.7%), desflurane exposure did not result in significant changes in NSC viability [lactate dehydrogenase (LDH) release] and NSC proliferation profile/rate by Cell Cycle Assay, in both short term (3 h) and prolonged (24 h) exposure groups. However, when monkey NSCs were guided to differentiate into neural cells (including neurons, astrocytes, and oligodendrocytes), and then exposed to desflurane (5.7%), no significant changes were detected in LDH release after a 3-h exposure, but a significant elevation in LDH release into the culture medium was observed after a 24-h exposure. Desflurane (24 h)-induced neural damage was further supported by increased expression levels of multiple cytokines, e.g., G-CSF, IL-12, IL-9, IL-10, and TNF-α compared with the controls. Additionally, our immunocytochemistry and flow cytometry data demonstrated a remarkable attenuation of differentiated neurons as evidenced by significantly decreased numbers of polysialic acid neural cell adhesion molecule (PSA-NCAM)-positive cells in the desflurane-exposed (prolonged) cultures. Our data suggests that at the clinically relevant concentration, desflurane did not induce NSC damage/death, but impaired the differentiated neuronal cells after prolonged exposure. Collectively, PSA-NCAM could be essential for neuronal viability. Desflurane-induced neurotoxicity was primarily associated with the loss of differentiated neurons. Changes in the neuronal specific marker, PSA-NCAM, may help understand the underlying mechanisms associated with anesthetic-induced neuronal damage. These findings should be helpful/useful for the understanding of the diverse effects of desflurane exposure on the developing brain and could be used to optimize the usage of these agents in the pediatric setting.

Since the discovery of their anesthetic effects, some neuroactive steroids have been used as general anesthetics. However, their effects on thalamocortical oscillations and potential sex differences that are associated with their hypnotic/sedative effects are not well studied. Here, we investigated spectral characteristics and sex differences in hypnotic effect of two common neuroactive steroids: Allopregnanolone (AlloP) and its synthetic analog Alphaxalone (Alpx) in wild type mice using behavioral testing (loss of righting reflex - LORR) and in vivo electrophysiology. Our data revealed sex-differences in LORR duration with 100 mg/kg intraperitoneally injected AlloP and Alpx confirming that females are more sensitive to neuroactive steroid-induced hypnosis. Spectral analysis, thalamocortical and corticocortical phase synchronization showed notable differences between two neuroactive steroids. AlloP induced a profound reduction in local field potential (LFP) and electroencephalogram (EEG) after LORR with higher LFP/EEG suppression in females during first 60 min after injection. Also, we observed a decrease in thalamocortical synchronization in lower (delta, theta, alpha) and increase in higher low gamma frequency in AlloP group; similar effects were observed in Alpx treated animals with no change in delta thalamocortical phase locking values. Synchronization between right and left cortex was reduced in all frequencies except low gamma in AlloP-treated group. Similarly, Alpx induced reduction in corticocortical synchronization for theta, alpha and beta frequencies. We conclude that AlloP and Alpx have distinct electrophysiological signatures in thalamocortical circuitry that may underly their sedative/hypnotic effects.

Acute exposure to a seizure-inducing dose of an organophosphorus nerve agent inhibits acetylcholinesterase, leading to pharmacoresistance if benzodiazepine treatment is delayed. Following soman-induced status epilepticus (SE) in rats, prolonged seizure is associated with severe and widespread neurodegeneration. We evaluated the aminothiol cystamine, the oxidized form of cysteamine, for neuroprotective potential against soman-induced SE and associated neurodegeneration. Cystamine has a myriad of effects including antioxidant properties, neuroprotective effects, and immunomodulation, among others, which is of interest in evaluating neuroprotective efficacy against cholinergic-induced neurodegeneration. Adult male rats implanted with telemetry transmitters for continuous EEG recording were exposed to soman and treated with the muscarinic antagonist atropine sulfate and the oxime asoxime dimethanesulfonate 1 min after exposure to increase survival. Midazolam was administered 30 min after seizure onset. Cystamine (10 or 50 mg/kg) or vehicle was administered 30 min after seizure onset and again 4 h after soman exposure. The initial seizure duration, the EEG power integral at 6 h after exposure, and the percentage of rats that developed spontaneous recurrent seizure were reduced in rats treated with cystamine, compared to those that received only midazolam. In addition, cystamine reduced neurodegeneration in seizure-sensitive brain regions following soman exposure, compared to midazolam. Our findings highlight the potential for aminothiols to serve as adjunctive therapy to midazolam in treating cholinergic-induced toxicity and suggest broader applications of aminothiols in neuroprotection and neurological disorders.

Dystonia, a challenging movement disorder, poses significant therapeutic challenges due to its resistance to treatment, resulting in both physical impairment and substantial mental distress, ultimately impacting overall quality of life. Cerebral palsy (CP) is a major non-genetic cause of secondary dystonia, characterized by diverse clinical presentations. This study aims to comprehensively evaluate the effectiveness of deep brain stimulation (DBS) as a therapeutic intervention for individuals with dystonic CP. We conducted a systematic analysis of studies assessing the safety and effectiveness of DBS, with a focus on its long-term outcomes [PROSPERO (Unique identifier: CRD42023399285)]. We examined factors that influence treatment response and proposed strategies to enhance patient quality of life. DBS, especially when targeting the basal ganglia or innovative targets, shows promise as a therapeutic approach for dystonic CP. While existing controlled studies confirm its safety and effectiveness, a thorough evaluation of long-term efficacy remains crucial. This research highlights the potential of DBS in improving the lives of individuals with dystonic CP, providing hope for further refinement, innovation, and broader clinical application of this therapeutic approach.

The threat of antimicrobial resistance in Ghana is increasing with the recent emergence of KAPE pathogens (K. pneumoniae, A. baumannii, P. aeruginosa and Enterobacter species) from the hospital environment. As opportunistic pathogens, KAPE leverage the formation of biofilms and swarms to survive stringent environmental conditions. As research continues to investigate approaches that bacteria employ to exacerbate infection, this study explored biofilm and swarm formation in MDR KAPE pathogens under polymyxin B stress emerging from Ghanaian hospitals. The antimicrobial susceptibility profile of KAPE pathogens to conventional antibiotics and polymyxin B was investigated via antibiotic disk diffusion and broth microdilution assays. Biofilm inhibition and eradication assays, swarm motility and a resazurin-based metabolic assay were used to profile bacterial phenotypic characteristics under polymyxin B stress. The strains exhibited resistance to the tested antibiotics with a high level of resistance to polymyxin B (PMB) (≥512 μg/mL). Additionally, the strains formed biofilms and bacterial swarms at 37°C. In the presence of PMB (≥512 μg/mL), KAPE pathogens formed swarms with no significant reduction in bacterial swarms at 1,048 μg/mL. Biofilm was observed for all strains with PMB neither inhibiting nor eradicating at high PMB (2048 μg/mL). Additionally, there were no significant differences in the phenotypic and antimicrobial susceptibility profiles of clinical and environmental KAPE pathogens from Ghanaian ICUs. Overall, the study established that clinical and environmental KAPE pathogens from Ghanaian ICUs exhibit adaptive phenotypic and resistance characteristics that could potentially enhance bacterial survival during host colonization and infection. This could undermine treatment strategies and pose public health challenges in Ghana.

An individual's genetics contributes to their risk of developing amyotrophic lateral sclerosis (ALS); however, there is still a large proportion of the heritability of ALS to be understood. Part of this missing heritability may lie in complex variants, such as the long interspersed element 1 (L1) retrotransposon, which have yet to be evaluated. The majority of L1 insertions in the human genome are no longer able to retrotranspose, but to date 279 retrotransposition-competent (RC) L1s have been reported. Many RC-L1s are polymorphic for their presence/absence; therefore, each individual will have a different number and complement of RC-L1s. These elements have been hypothesized to be involved in disease processes by multiple mechanisms such as somatic mutation by retrotransposition, the triggering of neuroinflammation and DNA damage. We hypothesize that L1s may influence disease development either through their effects on endogenous genes or through the properties that enable them to retrotranspose. Whole genome sequencing data from the New York Genome Center ALS consortium were used to characterize L1 variation identifying 2,803 polymorphic L1 elements and association analysis was performed in European individuals (ALS/ALS with other neurological disorder (ALSND) n = 2,653, controls n = 320). There were no individual L1 elements associated with disease, but we did identify a significant increase in the number of RC-L1s in ALS/ALSND genomes (p = 0.01) and the presence of ≥46 RC-L1s showed the most significant association (OR = 1.09 (1.02-1.16), p = 0.01) with disease. Analysis of individual L1s and their association with age at onset and survival identified one L1 whose presence was significantly associated with a lower age at onset (52.7 years) compared to homozygous absent individuals (59.2 years) (padj = 0.009). Our study has identified novel genetic factors for both disease risk and age at onset in ALS providing further evidence for the role of L1 retrotransposons in neurodegenerative diseases.

The relationship between drinking and sarcopenia remains controversial. The aim of the present study was to investigate the association of alcohol drinking with sarcopenia in the older adults. A prospective study with 5244 Chinese community-dwelling older adults aged ≥65 years was performed. Sarcopenia was assessed by appendicular skeletal muscle mass index, grip strength, and gait speed. A quantitative questionnaire was used to obtain the information of alcohol drinking. After 4-year follow-up, our study showed that drinkers had lower incidence of sarcopenia than those non-drinkers (19.4% vs. 30.4%, P < 0.001 in males and 9.5% vs. 20.4%, P = 0.004 in females, respectively). Moreover, male drinkers had higher levels of muscle mass [median (IQR): 7.3 (6.7-7.9) kg/m² vs. 7.1 (6.5-7.7) kg/m², P < 0.001] grip strength [median (IQR): 31.1 (26.5-35.0) kg vs. 29.6 (24.8-38.8) kg, P < 0.001], and gait speed [median (IQR): 1.08 (0.98-1.17) m/s vs. 1.05 (0.94-1.15) m/s, P < 0.001] than those non-drinkers, while female drinkers had higher gait speed [median (IQR): 1.02 (0.94-1.11) m/s vs. 0.99 (0.89-1.09) m/s, P = 0.031] than those non-drinkers. Multivariate logistic regression showed that in older adults younger than 85 years, both interim drinking (RR = 0.60; 95%CI = 0.39-0.93; P = 0.021 for males; RR = 0.36; 95%CI = 0.13-0.90; P = 0.035 for females) and daily drinking (RR = 0.78; 95%CI = 0.61-0.99; P = 0.045 for males; RR = 0.34; 95%CI = 0.12-0.96; P = 0.041 for females) were correlated with decreased risk of sarcopenia even after adjustment for confounding factors. However, our dose-response analysis did not show any significant relationship between daily alcohol intake and the risk of sarcopenia as well as the components of sarcopenia. In conclusion, our results indicated that alcohol drinking may not be a risk factor for sarcopenia in the older adults. Further research will help to understand the underlying mechanism of the observed causal relationship.

The identification of epidermal growth factor receptor (EGFR) tyrosine kinase (TK) domain mutations in non-small cell lung cancer (NSCLC) patients is crucial for therapeutic decision-making and monitoring EGFR-tyrosine kinase inhibitor (TKI) resistance. Liquid biopsy has emerged as a promising alternative for patients ineligible for invasive tissue sampling. This study investigated the clinical utility of a novel chip-based digital PCR (dPCR) platform for detecting two important EGFR mutations - exon 19 deletions (19del) and threonine-methionine amino acid substitution at position 790 (T790M) - in serum samples, while exploring potential serum biomarkers for mutation prediction. The collection of 350 serum samples were conducted on patients diagnosed with NSCLC at Huashan Hospital between August 2023 and February 2024. Cell-free deoxyribonucleic acid (cfDNA) was extracted from serum and was analyzed for EGFR mutations using dPCR. The serum tumor marker levels were quantified. The dPCR assay demonstrated positive predictive values of 73.33% for 19del and 28.57% for T790M. Biomarker analysis revealed a carbohydrate antigen (CA) 199 cutoff of 11.75 U/mL (AUC = 0.707, 95% CI: 0.573-0.841, P = 0.005) for 19del detection, while progastrin-releasing peptide (ProGRP) showed a cutoff of 45.15 pg/mL (AUC = 0.628, 95% CI: 0.521-0.735, P = 0.028) for T790M identification. Variant rate exhibited significant positive correlations with biomarker concentrations: 19del variant rates significantly associated with CA125 levels (r = 0.624, P = 0.010), while T790M correlated with both carcinoembryonic antigen (CEA) (r = 0.531, P = 0.004) and ProGRP (r = 0.395, P = 0.041) in mutation-positive cohorts. These findings indicate that serum-based dPCR liquid biopsy demonstrates potential clinical utility as a supplementary approach to tissue biopsy for NSCLC genotyping. Notably, elevated serum tumor marker levels correlate with enhanced mutation detection rates in liquid biopsy, implying their potential supplementary value in prioritizing patients for molecular profiling.

The fatal neurodegenerative disease, amyotrophic lateral sclerosis (ALS), leads to the degeneration of motor neurons in the brain and spinal cord. Many different genetic variants are known to increase the risk of developing ALS, however much of the disease heritability is still to be identified. To identify novel genetic factors, we characterised SINE-VNTR-Alu (SVA) presence/absence variation in 4403 genomes from the New York Genome Center (NYGC) ALS consortium. SVAs are a type of retrotransposon able to mobilise in the human genome generating new insertions that can modulate gene expression and mRNA splicing and to date 33 insertions are known to cause a range of genetic diseases. In the NYGC ALS consortium sequence data 2831 non-reference genome SVAs were identified and 95% of these insertions were rare with an insertion allele frequency of less than 0.01. Association analysis of the common SVAs with ALS risk, age at onset and survival did not identify any SVAs that survived correction for multiple testing. However, there were three different rare SVA insertions in the ALS associated gene NEK1 identified in four different individuals with ALS. The frequency of these rare insertions in NEK1 was significantly higher in the individuals with ALS from the NYGC ALS consortium compared to the gnomAD SV non-neuro controls (p = 0.0002). This study was the first to characterise non-reference SVA presence/absence variation in a large cohort of ALS individuals identifying insertions as potential candidates involved in disease development for further investigation.

Clinically, reliably restoring meaningful peripheral sensory and motor nerve function across peripheral nerve gaps is limited. Thus, although autografts are the clinical "gold standard" repair technique for bridging nerve gaps, even under relatively good conditions, <50% of patients recover meaningful function. Due to this low recovery rate, many patients are not even provided repair surgery and, consequently, suffer permanent loss of function. This paper examines intrinsic and extrinsic changes associated with injured neurons and Schwann cells that reduce the extent of axon regeneration and recovery. It also examines how these changes can be reversed, leading to enhanced regeneration and recovery. It next examines the efficacy of platelet-rich plasma (PRP) in promoting axon regeneration and two novel techniques involving bridging nerve gaps with an autograft within a platelet-rich (PRP) collagen tube or only a PRP-filled collagen tube, which induce meaningful recovery under conditions where autografts alone are not effective. Finally, it looks at potential mechanisms by which platelet-released factors may enhance axon regeneration and recovery. This review shows that although there are many limitations to restoring meaningful function following peripheral nerve trauma, there are a number of ways these can be overcome. Presently, the most promising techniques involve using PRP.