Global burden of hip fracture: The Global Burden of Disease Study.

This study is the first to measure global burden of hip fracture in patients aged 55 years and older across 204 countries and territories from 1990 to 2019. Our study further proved that the global burden of hip fracture is still large. Hip fractures among males are perhaps underestimated, and older adults should be given more attention. PURPOSE: Hip fracture is a tremendous universal public health challenge, but no updated comprehensive and comparable assessment of hip fracture incidence and burden exists for most of the world in older adults. METHODS: Using data from the Global Burden of Diseases (GBD) 2019, we estimated the number and rates of the incidence, prevalence, and years lived with disability (YLD) of hip fracture across 204 countries and territories in patients aged 55 years and older from 1990 to 2019. RESULTS: In 2019, the incidence, prevalence, and YLDs rates of hip fracture in patients aged 55 years and older were 681.35 (95% UI 508.36-892.27) per 100000 population, 1191.39 (95% UI 1083.80-1301.52) per 100000 population, and 130.78 (95% UI 92.26-175.30) per 100000 population. During the three decades, the incidence among people aged below 60 years showed a downward trend, whereas it showed a rapid upward trend among older adults. All the numbers and rates of hip fractures among females were higher than those among males and increased with age, with the highest number and rate in the highest age group. Notably, the male to female ratio of the incidence for people aged over 55 years increased from 0.577 in 1990 to 0.612 in 2019. Falls were the leading cause among both sexes and in all age groups. CONCLUSIONS: The incidence and the number of hip fractures among patients aged 55 years and older increased over the past three decades, indicating that the global burden of hip fracture is still large. Hip fractures among males are perhaps underestimated, and older adults should be given more attention.

Effects of Temperature, Moisture, and Ultraviolet Light on Germination, Infection, and Survival of Gymnosporangium yamadae Teliospores and Basidiospores.

Apple rust caused by Gymnosporangium yamadae is a significant disease in China's main apple production areas. We evaluated the effects of temperature, moisture, and ultraviolet (UV) light on the germination, infection, and survival of teliospore horns and basidiospores under artificially controlled environmental conditions. The temperature required for the germination and infection of teliospores and basidiospores of G. yamadae ranged from 5 to 25°C, with an optimum temperature of approximately 17°C. The teliospore horns germinated after soaking in distilled water for 5 min and required at least 2.3 h of development to produce basidiospores under the most favorable conditions. The basidiospores germinated only in free water and produced germ tubes 0.8 h after being placed in the water. The half-life of the basidiospore was 72.5 h in the dark and only 9.5 h when exposed to intense UV light. The basidiospores inoculated on the host leaves required at least 2.3 h of water exposure to cause rust lesions. A revised Weibull model could describe the relationships between the germination and infection of teliospore horns and basidiospores with temperature and wetness duration. Collectively, these results can serve as a valuable guide for developing a model to predict future apple rust epidemics and establish a method for effective control strategies.

Detection of Cytb Point Mutation (G143A) that Confers High-Level Resistance to Pyraclostrobin in Glomerella cingulata Using LAMP Method.

Glomerella leaf spot (GLS) caused by Glomerella cingulata is a newly emerging disease that results in severe defoliation and fruit spots in apples. In China, the compound of pyraclostrobin and tebuconazole was registered to control GLS in 2018 and has achieved excellent control efficiency. In this study, we showed that the high-level resistant isolates of G. cingulata to pyraclostrobin, caused by the point mutation at codon 143 (GGT→GCT, G143A) in the cytochrome b gene, has appeared in apple orchards in Shandong Province in 2020, and the resistance frequency was 4.8%. Based on the genotype of the resistant isolates, we developed a loop-mediated isothermal amplification (LAMP) assay for detection of the pyraclostrobin resistance. The LAMP assay was demonstrated to have good specificity, sensitivity, and repeatability, and it exhibited high accuracy in detecting pyraclostrobin resistance in the field. This study reported the resistance status of GLS to pyraclostrobin in Shandong Province and developed a molecular tool for the detection of pyraclostrobin resistance, which is of practical significance for the scientific control of GLS.

The Effect of Temperature and Moisture on Colonization of Apple Fruit and Branches by Botryosphaeria dothidea.

Botryosphaeria dothidea causes severe disease of apple trees in China. The process of conidium germination, colonization, and infection of apple fruit and branches was examined on 'Fuji' apple and the effect of temperature, surface wetness and relative humidity (RH), and host surface washates on these processes was studied in controlled environments. Initial germ tube development and hyphal growth resulted in the colonization of the host surface without forming an infection structure. Hyphae expanded radially across the host surface and, after entering lenticels, developed into a dense mycelium mass or differentiated pseudoparenchyma. Hyphae from the bottom of the pseudoparenchyma either directly penetrated the lenticel surface intercellularly through the cell layer, or formed an undifferentiated hypha that invaded the lenticel through cracks formed during the lenticel development. Conidial germination and hyphal colonization occurred at 10 to 40°C, with an optimum of approximately 28°C. Conidial germination required an RH > 95% or surface wetness but, for hyphal colonization, an RH > 90% was sufficient. Conidia germinated and formed germ tubes within 1 h under optimum conditions. However, the pathogen required a longer period at RH > 90% or surface wetness for hyphae to colonize and form pseudoparenchyma or dense mycelia on the host surface. Hyphal colonization is a crucial stage for infection of apple tissues by B. dothidea.

Progression of Symptoms Caused by Botryosphaeria dothidea on Apple Branches.

Until recently, the causal agent of Botryosphaeria canker was assumed to differ from that causing ring rot on fruit and warts on branches on apple trees in China and East Asia. However, recent research documented that Botryosphaeria dothidea caused both disease symptoms on apple. Inoculations with strains isolated from cankers and warts on branches were conducted to investigate symptom progression caused by B. dothidea and conditions inducing the two symptom types. The results confirmed that both cankers and warts are caused by B. dothidea. Warts are the results of hyperplasia and suberization of bark tissues induced by fungal infection, whereas cankers result from the rapid growth of hyphae from inside warts, lenticels, or wounds. Resistance to B. dothidea exists in living apple branches. When a living branch is infected via lenticels, the pathogen induces proliferation and suberization of cortical cells that restricts the growth and expansion of the hyphae, leading to warts. However, under certain stress conditions such as drought, the hyphae inside host tissues expand rapidly and kill cortical cells, leading to canker development. Host resistance may recover during active growth periods, which suppresses or even stops rapid expansion of the hyphae, leading to the intermediate symptom of canker warts. Abiotic factors, such as drought or high temperature in early spring, can result in rapid extension of colonized hyphae in branches and conversion of warts to cankers. Preventing this transition can be an important measure in managing Botryosphaeria canker on apple.

Effect of Rainfall and Temperature on Perithecium Production of Botryosphaeria dothidea on Cankered Apple Branches.

Botryosphaeria dothidea is a fungal pathogen causing canker, dieback, and fruit rot of apple trees worldwide. Ascospores are an important source of inoculum of Botryosphaeria canker in China. Experiments were conducted under both controlled and natural conditions to study perithecium formation in relation to environmental conditions. Perithecia of B. dothidea were detected on cankered lesions throughout the apple growing season except in July and in some years including August under natural conditions. On newly formed canker lesions, the first perithecium was detected as early as August, about 1 week after rainfall. Perithecia matured successively, lasting from early August to June of the next year, with a peak in late September or early October. Temperature and rainfall are two key environmental factors affecting perithecium formation. Under controlled conditions, perithecia were produced only on cankered shoots incubated at test temperatures of 20 and 25°C and wetted by >3 days of simulated rainfall per week. The number of perithecia produced on canker lesions increased with the increase in rainfall duration. Perithecia were formed on canker shoots exposed to rainfall only in June, July, and August but not in September. Rainfall of >3 days per week can be used to predict the initial formation of perithecia in the main apple production areas in China to assist disease management.

Effects of Temperature and Moisture on Conidia Germination, Infection, and Acervulus Formation of the Apple Marssonina Leaf Blotch Pathogen (Diplocarpon mali) in China.

Apple Marssonina leaf blotch (AMLB; Diplocarpon mali) is a severe disease of apple that mainly causes premature leaf defoliation in many apple growing areas worldwide. AMLB epidemic development is closely related to temperature and rainfall. In this study, the effects of temperature and moisture on conidium germination, infection on leaves, and acervulus production were investigated under controlled environments. The temperature required for conidium germination and infection ranged from 5 to 30°C, with the optimum at approximately 23°C. The temperature required for acervulus formation was slightly higher, with the optimum at 24.6°C. Wetness was needed in order for conidia to germinate and infect; only a few conidia germinated at 100% RH. However, lesions can produce acervuli in dry conditions. The minimum duration of leaf wetness required for conidia to complete the entire infection process was 14, 8, 4, and 6 h at 10, 15, 20, and 25°C, respectively. A model describing the effect of temperature and leaf wetness duration was built. The model estimated that the optimum temperature for conidial infection was 22.6°C and the minimum wetness duration required was 4.8 h. This model can be used to forecast D. mali conidial infection to assist in disease management in commercial apple production.

A Nursing Pain Assessment and Record Information System: Design and Application in the Oncology Department.

Pain is an unpleasant sensory and emotional feeling accompanying existing, impending, or potential tissue damage. Valid pain assessment and standardized pain documentation are important in oncology pain management; however, they are still deficient. Thus, we developed a pain assessment and record information system for nurses in the oncology department and implemented a questionnaire survey to evaluate users' acceptance of the system. The pain assessment system focused on usability and efficiency to provide a modified workflow that was safe, less time-consuming, patient centered, enjoyable, and efficient. The pain assessment and record chart types in the system enabled greater standardization of pain assessments and records. The application of the system greatly improved the efficiency of nursing in the oncology department, guiding nurses in an accurate and comprehensive patient pain assessment and contributing significantly to further improvement in pain care standards and care decisions. Nurses and doctors surveyed reported a high degree of satisfaction with factors such as saving time and improving the capacity of pain control, suggesting that the system enhanced the quality of pain management. Through this system, we can promote pain management, improving care quality for patients.

Long-term outcome of patients with persistent low-level elevation of human chorionic gonadotrophin.

AIM: The aim of this study was to investigate a series of patients with sustained low-level elevated human chorionic gonadotrophin (hCG) and explore the management of these patients. METHODS: A total of 47 patients with persistent low levels of hCG were selected for analysis between January 2002 and January 2014 at the Women's Hospital of Zhejiang University, Hangzhou, China. Data were retrospectively reviewed for patient characteristics, therapeutic strategies, and follow-ups. We compared the characteristics of patients who were and were not eventually considered to have malignancies. RESULTS: Among the 47 patients, 17 with persistent low-level elevated hCG and no detectable lesions were considered to have no active malignancy. Fifteen of the 17 patients had hCG levels that returned to normal range by the end of follow-up, while the remaining two did not. The other 30 patients were eventually diagnosed as having active malignancies due to detected lesions or increasing elevation of hCG. A large proportion of these patients were diagnosed with placental site trophoblastic tumor or epithelioid trophoblastic tumor. CONCLUSION: For patients with persistent low-level elevated hCG, frequent follow-up rather than any therapy is recommended. Treatment was considered effective and safe once diagnosis of active malignancy was confirmed.

Effects of Temperature, Humidity, and Wound Age on Valsa mali Infection of Apple Shoot Pruning Wounds.

Valsa canker, caused by Valsa mali, is a destructive disease of apple in China. The pathogen infects apple branches, mainly through pruning wounds, and causes branch and tree death. To determine the conditions required for V. mali infection through pruning wounds and growth within the xylem, pruning wounds on 1- to 4-year-old apple branches were inoculated with conidia in vitro under artificially controlled conditions and in vivo in the orchard. The effects of temperature, wetness duration, and wound age on conidial infection through pruning wounds as well as hyphal growth in the xylem were examined. The results showed that, after invading through pruning wounds, V. mali hyphae grew along xylem vessels, tracheids, and rays, expanding longitudinally and laterally. The hyphae could enter adjacent xylem vessels and tracheids through micropores to form a dense hyphal network. Wetness duration did not exhibit an essential effect on conidial infection from pruning wounds. Conidia spread to pruning wounds with rainwater could infect the xylem without any other extra moisture. Temperature for V. mali conidia infection through pruning wounds and hyphal extension in the xylem ranged from 5 to 35°C, with the optimum at 20°C. Pruning wounds made in late March were susceptible to V. mali infection in March, April, and May; the susceptibility was markedly deceased by June, and the pathogen could barely infect through the pruning wounds in November. The infected pruning wounds began to show symptoms from the spring of the following year. More than half of the observed Valsa canker lesions emerged in the spring of the second year, and new canker twigs were also developed from the inoculations in the spring of the third year. March, April, and May are the critical periods for protecting pruning wounds against infection by V. mali in China, and coating pruning wounds with protective film immediately after pruning is an easy and effective measure to protect the pruning wounds.

Effects of Temperature, Wetness Duration, and Moisture on the Conidial Germination, Infection, and Disease Incubation Period of Glomerella cingulata.

Glomerella leaf spot (GLS) caused by Glomerella cingulata is a newly emergent disease that results in severe defoliation and fruit spots. Currently, GLS is not effectively controlled in China due to a lack of understanding of its epidemiology. Therefore, the effects of temperature, wetness duration, and moisture on conidial germination, infection, and the disease incubation period of GLS were examined by inoculating cv. Gala apple leaves with a conidial suspension and performing in vitro germination assays. Conidia could germinate and form appressoria at temperatures ranging from 5 to 35°C, with an optimum temperature of 27.6°C. The germination of conidia required free water or a nearly saturated relative humidity, with only a few conidia germinating and forming appressoria when the RH was less than 99%. The conidial germination dynamics at 10, 25, and 30°C were well represented by three logistic models. The infection of cv. Gala apple leaves by conidia occurred at temperatures ranging from 15 to 35°C. The minimum wetness duration required for infection by conidia at different temperatures was described using a polynomial equation, and the lowest minimum wetness duration was 2.76 h, which occurred at 27.6°C according to the polynomial. Successful infection by conidia was represented by the number of lesions per leaf, which increased with extended wetness durations at the conidial infection stage for six tested temperatures, with the exception of 10°C, when the minimum wetness durations were satisfied. The associations of successfully infected conidia with wetness duration at temperatures of 15, 20, 25, and 30°C were described by four logistic models. Conidia infections developed into visible lesions at temperatures ranging from 15 to 30°C, and the shortest incubation period of 2 days was observed at 25°C. These data and models can be used to construct forecasting models and develop effective control systems for Glomerella leaf spot.

Risk Factors for Cerebrospinal Fluid Leakage After Extradural Spine Surgery: A Meta-Analysis and Systematic Review.

BACKGROUND: Cerebrospinal fluid (CSF) leakage is 1 of the common complications of spine surgery and is largely caused by intraoperative or postoperative dural tears. Associations of different factors with postoperative CSF leakage have not been consistent. In this study we aimed to identify demographic, disease-related, and surgical risk factors for CSF leakage after extradural spine surgery in a systematic review and meta-anlysis. METHODS: The PubMed, EMBASE, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure, Chinese Wanfang data, Chinese Weipu Database, and SinoMed databases were searched from inception until October 24, 2022. Fixed-effects or random-effects models were used to calculate odds ratios and 95% confidence intervals. The quality of observational studies was evaluated using the Newcastle-Ottawa scale instrument. RESULTS: A total of 15 observational studies with 1,719,923 participants were included in this systematic review. All studies had a Newcastle-Ottawa scale score greater than or equal to 6. Age older than 70 years, smoking, ossification of the posterior longitudinal ligament, adhesion of spinal dura, spinal canal stenosis, cervical fracture, spondylolisthesis, revision surgery, and multiple surgical segments were all related to CSF leakage in the pooled analysis. Obesity and disease duration>1 year were not associated with the leakage of CSF. CONCLUSIONS: This study will provide a reference for the identification of patients at high risk of developing CSF leakage, which suggests clinicians to strengthen the observation of drainage fluid in high-risk groups.

Importance of timing and training to implement awake prone positioning in patients with COVID-19: a single-center prospective observational study.

Background: Awake prone positioning (APP) is broadly implemented in patients with severe acute respiratory syndrome coronavirus 2 related disease [coronavirus disease 2019 (COVID-19)] admitted to hospital with severe respiratory distress syndrome. This prospective observational study aimed to explore the factors influencing the implementation of APP in patients with acute respiratory failure due to COVID-19. Methods: Patients with COVID-19, all hospitalized with positive X-ray findings and oxygen supplementation requirement, in the Respiratory Step-Down Unit of the Peking University Third Hospital between January 6th, 2023, and January 20th, 2023, were included in this study. Data regarding basic information, activities of daily living (ADLs) scores, oxygen therapy, vital signs, and duration of APP were collected to investigate the factors influencing prone positioning. Results: Among the 134 patients included, 55.2% showed an improvement in oxygen saturation 1 hour after APP. Logistic regression revealed that the pre-APP heart rate (HR) [odds ratio (OR) =1.032; P=0.046] and peripheral oxygen saturation (SpO2) (OR =0.720; P<0.001) were the associated factors of the improvement in SpO2 after treatment. Multiple linear regression revealed that the ADL scores and pre-APP respiratory rate (RR) were the associated factors of the duration of prone positioning (P<0.01). The APP technical steering group effectively improved duration of APP. Conclusions: Patients with low SpO2 and increased HR before treatment showed greater improvement in oxygen saturation. Patients with lower tolerance to ADL but lower RRs were those to demonstrate a longer duration of prone positioning. This is pointing towards establishing the most favorable time window for APP during the course of COVID-19: after the ADLs have already decreased, but before significant tachypnea has appeared.

[Explore the genotype characteristics of DNA repair enzyme XRCC1 and XPD in the lens epithelium associated with free radical level in the age-related cataract patients].

OBJECTIVE: To explore the genotype characteristics of DNA repair enzyme XPD-751 and XRCC1-399 in the lens epithelium of cataract patients, and difference in free radical level. METHODS: The genome DNA was extracted from respective lens epithelium of 30 cataract patients, their peripheral blood and 12 normal control's peripheral blood by using a Genomic DNA kit, and the polymorphisms of DNA repair enzymes XPD-751 and XRCC1-399 were examined by PCR-RFLP technique. Meanwhile, that of the cultured normal human lens epithelial SRA01/04 cells was carried out same way as reference control. Besides, the free radical level was detected by related kit. RESULTS: The XRCC1-Gln399Gln or XPD-Lys751Lys genotype was found in the normal control group and cultured human SRA01/04 cells, while the polymorphism of XPD-Lys751Gln could be found in both lens epithelium and blood cells of the cataract patient group. However, there was no difference in XRCC1-399 phenotype between the patient and the normal control groups. There is difference in free radical level between the cataract (0.204 ± 0.07; 0.188 ± 0.07) and healthy subjects (t = 211.20, P < 0.05). CONCLUSION: The polymorphism of XPD-Lys751Gln can be found in the lens epithelium of cataract patient group, suggesting that there may be association among the XPD-751 polymorphism with higher free radical level in the age-related cataract disease.

Baicalein Attenuates Severe Polymicrobial Sepsis via Alleviating Immune Dysfunction of T Lymphocytes and Inflammation.

OBJECTIVE: To investigate the effect of baicalein on polymicrobial sepsis-induced immune dysfunction and organ injury. METHODS: A sepsis model was induced in Sprague-Dawley rats via caecal ligation and puncture (CLP). Specific pathogen free rats were randomly divided into a sham group, CLP group and CLP + baicalein (Bai) group (n=16 each). Rats in the CLP + Bai group were intravenously injected with baicalein (20 mg/kg) at 1 and 10 h after CLP. Survival rate, bacterial load, and organ damage were assessed. Then each group was evaluated at 6, 12, and 24 h to investigate the effect of baicalein on immune cells and inflammatory cytokines in septic rats. RESULTS: Baicalein treatment significantly improved the survival of septic rats, decreased the bacterial burden, and moderated tissue damage (spleen, liver, and lung), as observed by haematoxylin and eosin staining. Septic rats treated with baicalein had strikingly increased proportions of CD3+CD4+ T cells and ratios of CD4+/CD8+ T cells in the peripheral blood and spleen (all P<0.05). Moreover, baicalein treatment decreased the apoptotic rate of whole white blood cells and spleen cells at 24 h after surgery (P<0.05). Baicalein significantly reduced the levels of tumor necrosis factor α and interleukin-6 (IL-6) and increased IL-10, and the expression levels of galectin 9 were also raised in the spleen (P<0.01). CONCLUSION: Baicalein may be an effective immunomodulator that attenuates overwhelming inflammatory responses in severe abdominal sepsis.

Effect of sacubitril valsartan on cardiac function and endothelial function in patients with chronic heart failure with reduced ejection fraction.

OBJECTIVE: The aim of the present study was to observe the effect of sacubitril valsartan on cardiac function and vascular endothelial function in patients with chronic heart failure with reduced ejection fraction (HFrEF). METHODS: A total of 80 patients with HFrEF were randomly divided into an observation group and a control group, with 40 patients in each group. Sacubitril valsartan was added to the conventional treatment in the observation group, and perindopril was added to the conventional treatment in the control group. Both groups were treated continuously for 12 weeks. The left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), flow-mediated vasodilatory function (FMD) of the brachial artery, and levels of plasma Ang II, endothelin 1 (ET-1), and calcitonin gene-related peptide (CGRP), together with the serum nitric oxide (NO) and NO synthase (NOS) were compared before and after treatment in the groups. RESULTS: Before the treatment, the levels of LVEF, LVEDD, FMD, Ang II, ET-1, CGRP, NO, and NOS in the observation group were not significantly different from those in the control group (P > 0.05). However, the levels of LVEF, FMD, CGRP, NO, and NOS in both groups were significantly higher after the treatment than those before the treatment (P < 0.05) and significantly higher in the observation group than those in the control group. The difference was statistically significant (P < 0.05). Meanwhile, the levels of LVEDD, Ang II, and ET-1 in both groups decreased significantly after the treatment (P < 0.05) and were significantly lower in the observation group than those in the control group. The difference was statistically significant (P < 0.05). CONCLUSION: Sacubitril valsartan might improve endothelial function while increasing cardiac function in HFrEF patients.

Growth of Pseudomorphic GeSn at Low Pressure with Sn Composition of 16.7.

Group-IV alloy GeSn holds great promise for the high-performance optoelectronic devices that can be monolithically integrated on Si for near- and mid-infrared applications. Growth of GeSn using chemical vapor deposition technique with various Sn and Ge precursors has been investigated worldwide. To achieve relatively high Sn incorporation, the use of higher pressure and/or higher order Ge hydrides precursors were reported. In this work, we successfully demonstrated the growth of high-quality GeSn with Sn composition of 16.7% at low pressure of 12 Torr. The alloy was grown using the commercially available GeH4 and SnCl4 precursors via a chemical vapor deposition reactor. Material and optical characterizations were performed to confirm the Sn incorporation and to study the optical properties. The demonstrated growth results reveal a low-pressure growth window to achieve high-quality and high Sn alloys for future device applications.

Hydrothermal synthesis of layered sodium manganese oxide nanowires and their electrochemical performance.

A new method for preparing black birnessite nanowires is introduced. Layer-structured manganese oxide nanowires were synthesized by a facile hydrothermal method, and using both NaMnO4 and CH3CH2OH as the precursors in a concentrated NaOH solution. The structure, composition, appearance and electrochemical performance of the product were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), energy diffraction (ED), high-resolution transmission electron microscopy (HRTEM), thermogravimetric analysis (TGA) and constant current charge/discharge. The XRD patterns showed a single phase corresponding to a crystalline birnessite-based manganese oxide. TEM studies suggested their wire-like structures. The TGA measurement demonstrated that they possessed an excellent thermal stability up to 400 degrees C. In the potential window of 2.0-4.3 V, the product exhibited excellent cyclic stability and rapid charge-discharge performance.

Chemokines and their receptors promoting the recruitment of myeloid-derived suppressor cells into the tumor.

Myeloid-derived suppressor cells (MDSCs) expand in tumor-bearing host. They suppress anti-tumor immune response and promote tumor growth. Chemokines play a vital role in recruiting MDSCs into tumor tissue. They can also induce the generation of MDSCs in the bone marrow, maintain their suppressive activity, and promote their proliferation and differentiation. Here, we review CCL2/CCL12-CCR2, CCL3/4/5-CCR5, CCL15-CCR1, CX3CL1/CCL26-CX3CR1, CXCL5/2/1-CXCR2, CXCL8-CXCR1/2, CCL21-CCR7, CXCL13-CXCR5 signaling pathways, their role in MDSCs recruitment to tumor tissue, and their correlation with tumor development, metastasis and prognosis. Targeting chemokines and their receptors may serve as a promising strategy in immunotherapy, especially combined with other strategies such as chemotherapy, cyclin-dependent kinase or immune checkpoints inhibitors.

The spleen contributes to the increase in PMN-MDSCs in orthotopic H22 hepatoma mice.

Myeloid-derived suppressor cells (MDSCs) are classified into polymorphonuclear (PMN)-MDSCs and monocytic (M)-MDSCs. The predominant subtype of MDSCs in hepatocellular carcinoma (HCC) is still elusive. The spleen is the largest immune organ in the body and is the origin of many cells. It is still unknown whether the spleen is the origin of MDSCs. In this study, we investigated the expression, origin and mobilization of the predominant MDSC subtype in H22 orthotopic hepatoma mice. Compared with M-MDSCs, PMN-MDSCs were increased and dominant in the spleen, peripheral blood and tumor tissues. Splenectomy could decrease the percentages of PMN-MDSCs in the peripheral blood and tumor tissues, increase the frequencies of NK cells in the peripheral blood and CD3+CD4+T, CD3+CD8+T, NK and NKT cells in the tumor tissues, reduce the tumor weight and the amounts of ascites, and prolong survival time in hepatoma mice. The levels of chemokine (CC motif) ligand 9 (CCL9) and chemokine (CC motif) ligand 2 (CCL2) were elevated in the peripheral blood of tumor-bearing (TB) mice, and their receptors CCR1 and CCR2 were expressed on spleen PMN-MDSCs. Migration assay showed that CCL2 and CCL9 could attract spleen PMN-MDSCs in vitro. These results indicate that PMN-MDSCs were increased and dominant in orthotopic H22 hepatoma mice, the spleen contributed to the increase of PMN-MDSCs, and PMN-MDSCs could be mobilized from the spleen to the peripheral blood by CCL9 and CCL2, thus facilitated tumor growth.