Evaluation of clinical characteristics and risk factors associated with Chlamydia psittaci infection based on metagenomic next-generation sequencing.

INTRODUCTION: Psittacosis is a zoonosis caused by Chlamydia psittaci, the clinical manifestations of Psittacosis range from mild illness to fulminant severe pneumonia with multiple organ failure. This study aimed to evaluate the clinical characteristics of Chlamydia psittaci infection diagnosed based on metagenomic next-generation sequencing(mNGS), as well as the risk factors affecting the progress of Chlamydia psittaci infection, in order to improve the effect of therapeutics. METHODS: We retrospectively analyzed the clinical data of patients infected with chlamydia psittaci in the First Affiliated Hospital of Nanchang University from January 2021 to December 2021. The patient's past medical history, clinical manifestations, laboratory examinations, chest CT results, treatment status, and prognosis data were collected. we also investigated both the pathogenic profile characteristics and the lower respiratory tract microbiota of patients with Chlamydia psittaci pneumonia using mNGS. RESULTS: All cases of Chlamydia psittaci in our research have been confirmed by mNGS. Among 46 cases of Chlamydia psittaci pneumonia, Poultry exposure was reported in 35 cases. In severe cases of Chlamydia psittaci pneumonia, Neutrophils, Procalcitonin (PCT), Lactate Dehydrogenase (LDH), Hydroxybutyrate Dehydrogenase (HBDH), Creatine Kinase Isoenzymes-B (CK-MB) and D-Dimer levels were remarkably higher than that of non-severe cases, except for lymphocytes (all P < 0.05). Chest CT scans showed Bilateral (77.8%), multiple lobar lungs (85.2%), pleural effusions (44.4%) involvement in those suffering from severe Chlamydia psittaci pneumonia, whereas its incidence was 0%, 21.1% and 10.5% in non-severe patients, respectively (P < 0.05). Multivariate analysis revealed that higher lymphocyte concentrations (OR 0.836, 95% CI 0.714-0.962, P = 0.041) were the only protective factor for survival. mNGS results indicated that 41.3% of patients (19/46) had suspected coinfections with a coinfection rate of 84.2% (16/19) in the severe group, much higher than that in the non severe group (p < 0.05). No significantly different profiles of lower respiratory tract microbiota diversity were found between non severe group and severe group. CONCLUSION: A history of poultry exposure in patients can serve as an important basis for diagnosing Chlamydia psittaci pneumonia, and patients with severe Chlamydia psittaci pneumonia are more likely to develop elevated inflammatory biomarkers as well as elevated cardiac markers. Higher lymphocyte concentrations are protective factors associated with severe C. psittaci pneumonia. The higher proportion of patients with coinfections in our study supports the use of mNGS for comprehensive early detection of respiratory infections in patients with C. psittaci pneumonia.

Prophylactic effect of exogenous melatonin and melatonin receptor agonists on postoperative delirium in elderly patients: a systemic review and meta-analysis of randomized controlled trials.

BACKGROUND: The prophylactic effect of exogenous melatonin and melatonin receptor agonists (MMRAs) on postoperative delirium (POD) in elderly patients remains controversial. OBJECTIVE: This study aimed to assess the prophylactic effect of MMRAs on POD by conducting a systemic review and meta-analysis of randomized controlled trials (RCTs). METHODS: We systematically searched four electronic databases including PubMed, Web of Science, Cochrane Library, and Embase for the eligible studies up to February 28, 2023. The Cochrane risk of bias tool was used for assessing the risk of bias in the included RCTs. The occurrence of POD was the primary outcome. The quality of evidence was evaluated by Grading of Recommendations Assessment, Development, and Evaluation. RESULTS: A total of 11 RCTs comprising patients (MMRA group: 777 patients and placebo group: 781 patients) were included. The results of the meta-analysis showed that the MMRA group had a lower occurrence of POD than the placebo group (risk ratio = 0.70, 95% confidence interval: 0.51-0.97, P < 0.05, I2 = 59%). The subgroup analysis showed that melatonin significantly reduced the occurrence of POD (moderate-quality evidence), whereas ramelteon and tryptophan had no significant impact (moderate-quality evidence). CONCLUSION: Existing evidence suggested that perioperative use of melatonin can prevent POD in elderly patients.

PSiTE: a Phylogeny guided Simulator for Tumor Evolution.

SUMMARY: Simulating realistic clonal dynamics of tumors is an important topic in cancer genomics. Here, we present Phylogeny guided Simulator for Tumor Evolution, a tool that can simulate different types of tumor samples including single sector, multi-sector bulk tumor as well as single-cell tumor data under a wide range of evolutionary trajectories. Phylogeny guided Simulator for Tumor Evolution provides an efficient tool for understanding clonal evolution of cancer. AVAILABILITY AND IMPLEMENTATION: PSiTE is implemented in Python and is available at https://github.com/hchyang/PSiTE. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Resveratrol Promotes Recovery of Hearing following Intense Noise Exposure by Enhancing Cochlear SIRT1 Activity.

The sirtuin SIRT1 is a highly conserved nicotinamide adenine dinucleotide (NAD)-dependent protein deacetylase known to have protective effects against a wide range of neurological disorders. In the present study, we discovered that C57BL/6 mice fed a long-term diet supplemented with high-dose resveratrol exhibited increased cochlear SIRT1 activity and presented a better recovery of hearing and less loss of hair cells after intense noise exposure compared with those fed a standard chew. Moreover, resveratrol attenuated cochlear SIRT1 decrease and reduced oxidative stress in the cochlea after noise exposure. These results suggest a considerable therapeutic potential of resveratrol for the treatment of noise-induced hearing loss.

Crystal Fluidity Reflected by Fast Rotational Motion at the Core, Branches, and Peripheral Aromatic Groups of a Dendrimeric Molecular Rotor.

Low packing densities are key structural features of amphidynamic crystals built with static and mobile components. Here we report a loosely packed crystal of dendrimeric rotor 2 and the fast dynamics of all its aromatic groups, both resulting from the hyperbranched structure of the molecule. Compound 2 was synthesized with a convergent strategy to construct a central phenylene core with stators consisting of two layers of triarylmethyl groups. Single crystal X-ray diffraction analysis confirmed a low-density packing structure consisting of one molecule of 2 and approximately eight solvent molecules per unit cell. Three isotopologues of 2 were synthesized to study the motion of each segment of the molecule in the solid state using variable temperature quadrupolar echo (2)H NMR spectroscopy. Line shape analysis of the spectra reveals that the central phenylene, the six branch phenylenes, and the 18 periphery phenyls all display megahertz rotational dynamics in the crystals at ambient temperature. Arrhenius analysis of the data gives similar activation energies and pre-exponential factors for different parts of the structure. The observed pre-exponential factors are 4-6 orders of magnitude greater than those of elementary site-exchange processes, indicating that the dynamics are not dictated by static energetic potentials. Instead, the activation energies for rotations in the crystals of 2 are controlled by temperature dependent local structural fluctuations and crystal fluidity.

Effect of repetitive transcranial magnetic stimulation on auditory function following acoustic trauma.

Repetitive transcranial magnetic stimulation (rTMS) is one form of non-invasive brain stimulation and increasingly shows neuroprotection in multiple neurological disorders. However, the potential of rTMS for protective action on auditory function following acoustic trauma has not been investigated. Here, we examined effect of TMS on hearing conservation, neurons survival and brain-derived neurotrophin factor (BDNF) expression in the cochlea and auditory cortex following acoustic trauma in rats. Wistar rats were exposed to intense pure tone noise (10 kHz, 120 dB SPL for 2 h) followed by rTMS treatment or sham treatment (handling control) daily for 14 days. Auditory brainstem response revealed there was no significant difference in hearing threshold shifts between rTMS- and sham-treated rats, although rTMS-treated rats showed less neuron loss in the auditory cortex in comparison with sham rats. Additionally, acoustic trauma increased BDNF expression in the cochlea and auditory cortex, and this elevation could be attenuated by rTMS treatment. Our results suggest present regiment of rTMS does not protect hearing against acoustic trauma, but maybe have implications for tinnitus treatment.

High-Throughput Measurement of Binding Kinetics by mRNA Display and Next-Generation Sequencing.

There is great demand for high-throughput methods to characterize ligand affinity. By combining mRNA display with next-generation sequencing, we determined the kinetic on- and off-rates for over twenty thousand ligands without the need for synthesis or purification of individual members. Our results are reproducible and as accurate as those obtained with other methods of affinity measurement.

Immunofluorescence protects RNA signals in simultaneous RNA-DNA FISH.

Cell research often requires combinational detection of RNA and DNA by fluorescence in situ hybridization (RNA-DNA FISH). However, it is difficult to preserve the fragile RNA signals through the harsh conditions used to denature the DNA template in DNA FISH. The current protocols of RNA-DNA FISH still cannot work robustly in all experiments. RNA-DNA FISH remains as a technically challenging and tedious experiment. By incorporating protein components into the signal detection steps of RNA FISH, which is then followed by a post-fixation step, we established an improved protocol of RNA-DNA FISH. The established method worked satisfyingly and robustly in our studies on Xist (inactivated X chromosome specific transcript) RNA and Terra (telomeric repeat-containing RNA). Our results provided the direct evidence to show that, not all the telomeres are associated with Terra, and a significant fraction of Terra foci do not overlap with telomere DNA in interphase cell nuclei. The improved method of simultaneous RNA-DNA FISH is reliable and time-efficient. It can be used in a variety of biological studies.

The microbiological diagnostic performance of metagenomic next-generation sequencing in patients with infectious diseases.

OBJECTIVE: Metagenomic next-generation sequencing (mNGS) can be used to detect pathogens in clinical infectious diseases through the sequencing analysis of microbial and host nucleic acids in clinical samples. This study aimed to assess the diagnostic performance of mNGS in patients with infections. METHODS: In this study, 641 patients with infectious diseases were enrolled. These patients simultaneously underwent pathogen detection by both mNGS and microbial culture. Through statistical analysis, we judged the diagnostic performance of mNGS and microbial culture on different pathogens. RESULTS: Among 641 patients, 276 cases of bacteria and 95 cases of fungi were detected by mNGS, whereas 108 cases of bacteria and 41 cases of fungi were detected by traditional cultures. Among all mixed infections, combined bacterial and viral infections were the highest (51%, 87/169), followed by combined bacterial with fungal infections (16.57%, 28/169) and mixed bacterial, fungal, and viral infections (13.61%, 23/169). Among all sample types, bronchoalveolar lavage fluid (BALF) samples had the highest positive rate (87.8%, 144/164), followed by sputum (85.4%, 76/89) and blood samples (61.2%, 158/258). For the culture method, sputum samples had the highest positive rate (47.2%, 42/89), followed by BALF (37.2%, 61/164). The positive rate of mNGS was 69.89% (448/641), which was significantly higher than that of traditional cultures (22.31% [143/641]) (P < .05). CONCLUSIONS: Our results show that mNGS is an effective tool for the rapid diagnosis of infectious diseases. Compared with traditional detection methods, mNGS also showed obvious advantages in mixed infections and infections with uncommon pathogens.

Tropheryma whipplei detected by metagenomic next-generation sequencing in bronchoalveolar lavage fluid.

Whipple's disease is a chronic systemic infectious disease that mainly affects the gastrointestinal tract. In some cases, Tropheryma whipplei can cause infection at the implant site or even throughout the body. In this study, we collected alveolar lavage fluid samples from patients with Tropheryma whipplei from 2020 to 2022, and retrospectively analyzed the clinical data of Tropheryma whipplei positive patients. Patient's past history, clinical manifestations, laboratory examinations, chest CT findings, treatment, and prognosis were recorded. 16 BALFs (70/1725, 4.0 %) from 16 patients were positive for Tropheryma whipplei. 8 patients were male with an average age of 50 years. The main clinical symptoms of patients included fever (9/16), cough (7/16), dyspnea (7/16), and expectoration (5/16), but neurological symptoms and arthralgia were rare. Cardiovascular and cerebrovascular diseases were the most common comorbidity (n=8). The main laboratory characteristics of the patient are red blood cell count, hemoglobin, total protein and albumin below normal levels (11/16), and/or creatinine above normal levels(14/16). Most chest computed tomography mainly show focal or patchy heterogeneous infection (n=5) and pleural effusion (n=8). Among the 6 samples, Tropheryma whipplei was the sole agent, and Klebsiella pneumoniae was the most common detected other pathogens. Metagenomic next-generation sequencing technology has improved the detection rate and attention of Tropheryma whipplei. Further research is needed to distinguish whether Tropheryma whipplei present in respiratory samples is a pathogen or an innocent bystander.

Haemophilus aphrophilus and Eikenella corrodens Coinfection of Brain: An Unusual Case from China.

Background: The HACEK group comprises Haemophilus spp., Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae, are Gram-negative bacteria that are slow-growing and fastidious. These organisms are common causes of culture-negative endocarditis. However, brain abscesses caused by Haemophilus aphrophilus and E. corrodens have been rarely reported. The case we describe, which was promptly identified and successfully treated, will be meaningful for the diagnosis and treatment of such infectious diseases. Case Presentation: Herein, we report a case of brain abscess in a young man who was infected with Haemophilus aphrophilus and E. corrodens. The patient was admitted to the hospital with sudden onset of vomiting, coma, and fever. Magnetic resonance imaging (MRI) of the brain and cerebrospinal fluid cell counts suggested cerebral abscess, he underwent drainage of the abscess and empirical antimicrobial therapy of meropenem (2 g every 8 hours) and linezolid (0.6 g every 12 hours) for more than 10 days without significant improvement. Metagenomic next-generation sequencing (mNGS) of drainage fluid and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) detection for isolated bacteria from samples suggested the presence of H. aphrophilus and E. corrodens. After 7 weeks of ceftriaxone (2 g every 12 hours) and meropenem (2 g every 8 hours) intravenously, the patient was discharged with a normal temperature and brain MRI showed improvement of the lesion. Conclusion: Similar cases reported in previous studies were always associated with bacterial blood dissemination after dental surgery or myocarditis; however, the patient in our case had no any associated risk factors. As far as we know, this is the only case of central nervous system infection caused by H. aphrophilus and E. corrodens that has utilized combined mNGS and MALDI-TOF MS in the diagnosis.

Application of Dexmedetomidine as an Opioid Substitute in Opioid-Free Anesthesia: A Systematic Review and Meta-analysis.

BACKGROUND: Opioid-based general anesthesia was previously used to alleviate perioperative pain; however, several complications associated with using anesthesia have raised several concerns. Various studies have investigated the application prospect of using opioid-free general anesthesia, such as dexmedetomidine, as an opioid substitute. OBJECTIVES: We performed a systematic review and meta-analysis to explore and highlight the safety and effectiveness of dexmedetomidine as an opioid substitute for opioid-free anesthesia. STUDY DESIGN: A systematic review and meta-analysis. SETTING: We screened for suitable clinical trials from electronic databases, including "PubMed," "Cochrane Library," "EMBASE," and "Web of Science." Eligible trials were included in this meta-analysis. METHODS: The quality of the screened randomized controlled trials (RCTs) was determined using the risk of bias assessment criteria by the Cochrane Collaboration tool. We used the "Review Manager 5.3" and "Stata 10.0" software to perform the meta-analysis. We evaluated the quality of evidence using the "Grading of Recommendations Assessment, Development, and Evaluation" approach. RESULTS: For the analysis, we included 32 RCTs encompassing 2,509 patients. In the opioid-free group, the 2-hour postoperative pain score of patients (mean difference = -0.53, 95% CI: -1.00, -0.07; P = 0.02, I2=78%) was significantly lower compared to those in the opioid-based group. In addition, several patients required rescue analgesia (risk ratio = 0.70, 95% CI: 0.58, 0.84, P < 0.05, I2 = 71%) and opioids postsurgery. However, the duration of extubation and postanesthesia care unit, as well as the incidences of bradycardia, were high in patients receiving dexmedetomidine as opioid-free general anesthesia. LIMITATIONS: Subgroup analysis for different anesthesia-maintaining drugs had not been conducted. The heterogeneity did not reduce after subgroup analysis. Different doses of dexmedetomidine had not been evaluated. CONCLUSIONS: These findings indicate that opioid-free general anesthesia based on dexmedetomidine could be effective; however, prolonged extubation time and cardiovascular complications are a few risks associated with dexmedetomidine.

The effect of magnesium sulfate on emergence agitation in children undergoing general anesthesia: A systematic review and meta-analysis.

STUDY OBJECTIVE: Emergence agitation (EA) is a common complication in pediatric patients after general anesthesia. The effectiveness of magnesium sulfate in decreasing the incidence of EA in children remains controversial. Therefore, a systematic review and meta-analysis was performed to assess the efficacy of magnesium sulfate in preventing EA in pediatric patients following general anesthesia. DESIGN: Systematic review and meta-analysis. SETTING: PubMed, Embase, Web of Science, and Cochrane Library were searched to identify eligible randomized controlled trials from their respective database inception dates to June 30, 2021. PATIENTS: Pediatric patients (< 18 years old) undergoing general anesthesia. INTERVENTIONS: Intravenous administration of magnesium sulfate. MEASUREMENTS: The primary outcome of the meta-analysis was EA incidence. The risk of bias of the included studies was evaluated using the revised Cochrane risk of bias tool for randomized trials (RoB 2.0). Grading of Recommendations, Assessment, Development, and Evaluation was applied to assess the level of certainty. MAIN RESULTS: Eight studies with 635 participants were identified. The forest plot revealed no significant difference in the incidence of EA between patients treated with magnesium sulfate and the control group (risk ratio = 0.69, 95% confidence interval [0.44, 1.07]; P = 0.10, I2 = 74%, moderate level of certainty). Additionally, magnesium sulfate did not reduce postoperative pediatric anesthesia emergence delirium scores but prolonged the emergence time. No significant differences were observed in postoperative complications (nausea, vomiting, laryngospasm, breath-holding, coughing, oxygen desaturation, and cardiac arrhythmias). CONCLUSIONS: Administration of magnesium sulfate during general anesthesia did not affect the occurrence of EA in pediatric patients. However, magnesium sulfate can prolong the emergence time without adverse effects. PROSPERO registration number: CRD42021252924.

miR-34a/ATG9A/TFEB Signaling Modulates Autophagy in Cochlear Hair Cells and Correlates with Age-related Hearing Loss.

Our previous studies revealed that miR-34a suppresses autophagy in the ageing cochlea, which correlates with cochlear hair cell loss and age-related hearing loss (AHL). However, the mechanisms underlying miR-34a regulation of autophagy in the cochlea remain unclear. Here, we show that nuclear translocation of transcription factor EB (TFEB), a master regulator of autophagy, was regulated by miR-34a in HEI-OC1 cells. Moreover, ATG9A, one of the main targets of miR-34a, was shown to interact with TFEB and thus promote its nuclear translocation in HEI-OC1 cells. Rapamycin rescued the inhibition of TFEB nuclear translocation induced by miR-34a/ATG9A activation, restored autophagic flux and consequently prevented HEI-OC1 cell death. Long-term supplementation with rapamycin attenuated outer hair cells (OHCs) and inner hair cell synaptic ribbons, and delayed AHL in C57BL/6 mice. Most importantly, rapamycin partially restored TFEB's nuclear localization and autophagic flux in OHCs of the ageing cochlea. These findings open new avenues for protection against AHL through miR-34a/ATG9a/TFEB modulation of autophagy.

Ondansetron Reduces the Incidence of Hypotension after Spinal Anaesthesia: A Systematic Review and Meta-Analysis.

Hypotension induced by spinal anaesthesia is a common clinical complication associated with multiple perioperative adverse events. We conducted a systemic review and meta-analysis to confirm whether ondansetron could alleviate hypotension following spinal anaesthesia. PubMed, Embase, Web of Science, and Cochrane Library were searched to identify eligible randomised controlled trials from their respective database inception dates to 30 September 2022. The primary outcome of the meta-analysis was the incidence of hypotension after spinal anaesthesia. The risk of bias in the included studies was evaluated using the revised Cochrane risk of bias tool for randomised trials (RoB 2.0). Grading of Recommendations, Assessment, Development, and Evaluation was applied to assess the level of certainty. A total of 25 studies were included in this research. The meta-analysis revealed that ondansetron significantly decreased the incidence of hypotension (RR = 0.65, 95% CI 0.53−0.80, p < 0.01, I2 = 64%) and bradycardia. In addition, patients treated with ondansetron had a reduced need for vasopressors administration. This study suggests that ondansetron may be recommended as a prophylaxis for hypotension and bradycardia following spinal anaesthesia; the level of evidence was moderate with a high level of heterogeneity.

Low-frequency electroacupuncture improves disordered hepatic energy metabolism in insulin-resistant Zucker diabetic fatty rats via the AMPK/mTORC1/p70S6K signaling pathway.

BACKGROUND AND AIM: Disordered hepatic energy metabolism is found in obese rats with insulin resistance (IR). There are insufficient experimental studies of electroacupuncture (EA) for IR and type 2 diabetes mellitus (T2DM). The aim of this study was to probe the effect of EA on disordered hepatic energy metabolism and the adenosine monophosphate (AMP)-activated protein kinase (AMPK)/mammalian target of rapamycin complex 1 (mTORC1)/ribosomal protein S6 kinase, 70-kDa (p70S6K) signaling pathway. METHODS: Zucker Diabetic Fatty (ZDF) rats were randomly divided into three groups: EA group receiving EA treatment; Pi group receiving pioglitazone gavage; and ZF group remaining untreated (n = 8 per group). Inbred non-insulin-resistant Zucker lean rats formed an (untreated) healthy control group (ZL, n = 8). Fasting plasma glucose (FPG), fasting insulin (FINS), C-peptide, C-reactive protein (CRP) and homeostatic model assessment of insulin resistance (HOMA-IR) indices were measured. Hematoxylin-eosin (H&E) staining was used to investigate the liver morphologically. The mitochondrial structure of hepatocytes was observed by transmission electron microscopy (TEM). Western blotting was adopted to determine protein expression of insulin receptor substrate 1 (IRS-1), mTOR, mTORC1, AMPK, tuberous sclerosis 2 (TSC2) and p70S6K, and their phosphorylation. RT-PCR was used to quantify IRS-1, mTOR, mTORC1, AMPK and p70S6K mRNA levels. RESULTS: Compared with the ZF group, FPG, FINS, C-peptide, CRP and HOMA-IR levels were significantly reduced in the EA group (p < 0.05, p < 0.01). Evaluation of histopathology showed improvement in liver appearances following EA. Phosphorylation levels of AMPK, mTOR and TSC2 decreased, and IRS-1 and p70S6K increased, in hepatocytes of the ZF group, while these negative effects appeared to be alleviated by EA. CONCLUSIONS: EA can effectively ameliorate IR and regulate energy metabolism in the ZDF rat model. AMPK/mTORC1/p70S6K and related molecules may represent a potential mechanism of action underlying these effects.

Glucose Protects Cochlear Hair Cells Against Oxidative Stress and Attenuates Noise-Induced Hearing Loss in Mice.

Oxidative stress is the key determinant in the pathogenesis of noise-induced hearing loss (NIHL). Given that cellular defense against oxidative stress is an energy-consuming process, the aim of the present study was to investigate whether increasing energy availability by glucose supplementation protects cochlear hair cells against oxidative stress and attenuates NIHL. Our results revealed that glucose supplementation reduced the noise-induced formation of reactive oxygen species (ROS) and consequently attenuated noise-induced loss of outer hair cells, inner hair cell synaptic ribbons, and NIHL in CBA/J mice. In cochlear explants, glucose supplementation increased the levels of ATP and NADPH, as well as attenuating H2O2-induced ROS production and cytotoxicity. Moreover, pharmacological inhibition of glucose transporter type 1 activity abolished the protective effects of glucose against oxidative stress in HEI-OC1 cells. These findings suggest that energy availability is crucial for oxidative stress resistance and glucose supplementation offers a simple and effective approach for the protection of cochlear hair cells against oxidative stress and NIHL.

Simultaneous RNA-DNA FISH.

A highly useful tool for studying lncRNAs is simultaneous RNA-DNA FISH, which reveals the localization and quantitative information of RNA and DNA in cellular contexts. However, a simple combination of RNA FISH and DNA FISH often generates disappointing results because the fragile RNA signals are often damaged by the harsh conditions used in DNA FISH for denaturing the DNA. Here, we describe a robust and simple RNA-DNA FISH protocol, in which amino-labeled nucleic acid probes are used for RNA FISH . The method is suitable to detect single RNA molecules simultaneously with DNA.

Application of controlled low central venous pressure during hepatectomy: A systematic review and meta-analysis.

STUDY OBJECTIVE: Previous studies reported that controlled low central venous pressure (CVP) can reduce blood loss during liver resection. This systematic review and meta-analysis sought to explore the efficacy and safety of low CVP in patients undergoing hepatectomy. DESIGN: A systematic review and meta-analysis of randomized controlled trials (RCTs). REVIEW METHODS: RCTs were searched in PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, Chinese BioMedical database, Chinese Scientific Journals Database, and Wanfang database from inception to April 30, 2021. Subgroup analyses were performed based on different surgical methods (open hepatectomy vs laparoscopic hepatectomy) and published countries (China vs other countries). The quality of evidence was assessed by Grading of Recommendations, Assessment, Development, and Evaluation. MAIN RESULTS: Eighteen RCTs containing 1285 participants (626 patients in the low CVP group and 659 patients in the control group) were included in this study. The forest plot showed that low CVP effectively reduced blood loss during liver resection compared with the control group (MD = -311.92 mL, 95% CI [-429.03, -194.81]; P < 0.001, I2 = 96%). Furthermore, blood transfusion volume (MD = -158.85 mL, 95% CI [-218.30, -99.40]; P < 0.001, I2 = 55%) and the number of patients requiring transfusion (RR 0.41, 95% CI 0.27-0.65, P < 0.001, I2 = 0%) were decreased in the low CVP group. Subgroup analyses showed similar results. Notably, the alanine transaminase level was significantly lower in the low CVP group during the first five postoperative days. However, no significant differences were observed for other postoperative liver function indicators (aspartate aminotransferase, total bilirubin, serum albumin, and prothrombin time), renal function indicators (blood urea nitrogen and serum creatinine) and perfusion parameters (heart rate, mean arterial pressure, and urine volume). The incidence of complications was similar between the two groups. CONCLUSION: The findings of this study showed that low CVP is effective and safe during hepatectomy. Therefore, this technique is recommended to reduce blood loss during hepatectomy. PROSPERO registration number: CRD42021232829.