ABSTRACT
Objective: To investigate the correlation between hematocrit (HCT) and cardiovascular events in peritoneal dialysis (PD) patients. Methods: Patients undergoing maintenance PD in the PD center of Guizhou Provincial People's Hospital from March 19, 2012 to July 9, 2020 were included. Demographic, baseline clinical and laboratory data of the patients were collected and patients were followed up until April 8, 2022. The primary endpoint was the first occurrence of a cardiovascular event. According to the tertiles of baseline HCT, the patients were divided into group Q1 (HCT≤26.6%), group Q2 (HCT>26.6%-32.4%), and group Q3 (HCT>32.4%). Laboratory indexes and cardiovascular events were compared among the three groups. Kaplan-Meier survival curve, Cox regression analysis and sensitivity analysis were used to analyze the effect of HCT on cardiovascular outcomes. Receiver operating characteristic (ROC) curve was used to analyze the predictive value of HCT for cardiovascular events in PD patients. Results: A total of 860 PD patients were included, including 494 males (57.4%) and 366 females (42.6%), with a mean age of (41.5±15.0) years. There were 287 cases in group Q1, 289 cases in group Q2, and 284 cases in group Q3, respectively. A total of 265 (30.8%) patients experienced first cardiovascular events during the follow-up period. The incidence of cardiovascular events in groups Q1, Q2 and Q3 was 36.2% (104/287), 34.3% (99/289), and 21.8% (62/284), respectively, with a statistically significant difference (P<0.001). The incidence of cardiovascular events decreased with the increase of HCT. Multivariate Cox proportional hazards regression model analysis showed that decreased HCT was a risk factor for cardiovascular events. Compared with group Q3, the risk of cardiovascular events in group Q1 increased by 50.7% (group Q2: HR=1.444, 95%CI: 1.029-2.028, P=0.034; group Q1: HR=1.570, 95%CI: 1.096-2.250, P=0.014). In the sensitivity analysis, using kidney transplantation as the competition event, the risk of cardiovascular events was lower in group Q3 than that in group Q1 (subdistributional HR=1.413, 95%CI: 1.006-1.990, P=0.046). Kaplan-Meier survival curve showed that compared with the other two groups, the cardiovascular events-free survival rate of patients in group Q1 was significantly lower (log-rank χ2=9.722, P=0.008). ROC analysis showed that the area under the curve (AUC) of HCT for predicting cardiovascular events in PD patients was 0.583 (95%CI: 0.542-0.623, P<0.001), with the sensitivity of 40.6% and the specificity of 75.1%. Conclusion: Low-level HCT is associated with an increased risk of the first cardiovascular event in PD patients.
Subject(s)
Cardiovascular Diseases , Peritoneal Dialysis , Humans , Male , Female , Retrospective Studies , Cardiovascular Diseases/etiology , Adult , Middle Aged , Hematocrit , Risk Factors , Proportional Hazards ModelsSubject(s)
Esophagoplasty , Intubation, Gastrointestinal , Humans , Anastomosis, Surgical , IntestinesABSTRACT
Objective: To explore the mechanism of early pancreatic exocrine function changes in severely scalded rats. Methods: The experimental research methods was used. Eighty male Sprague-Dawley rats aged 7-8 weeks were divided into simple sham injury group (n=8), sham injury+cholecystokinin octapeptide (CCK8) group (n=8), severe scald+CCK8 group (n=32), and extremely severe scald+CCK8 group (n=32) by the random number table, which were treated accordingly. Immediately after injury of rats in the 2 sham injury groups and 1, 2, 3, and 7 days after injury of rats in the 2 scald groups, the improved methods including pancreatic duct puncture and catheterization were used to dynamically collect the pancreatic-bile juice (PBJ) of rats. The PBJ secretory volume within 1 h was recorded, and the content of pancreatic lipase, α-amylase, and trypsin in PBJ was detected by enzyme-linked immunosorbent assay (ELISA), and the number of samples was 8. The femoral venous blood was collected, and the concentrations of pancreatic lipase and α-amylase in serum were detected by standard colorimetry to reflect their activity (n=8). The pancreatic tissue was extracted, and the levels of interleukin-1ß (IL-1ß) and IL-6 in pancreatic tissue were detected by ELISA (n=8), the expression of hypoxia-inducible factor 1α (HIF-1α) in pancreatic tissue was detected by immunofluorescence method, and the histopathological changes in pancreatic tissue were observed by hematoxylin-eosin staining, the severity of pancreatic tissue injury in the 2 scald groups was evaluated by modified Schmidt method (n=6), and the ultrastructure of acinar cells in pancreatic tissue was observed by transmission electron microscopy. Data were statistically analyzed with analysis of variance for factorial design, Tukey test, independent sample t test, and least significant difference test. Results: Compared with the PBJ secretory volume (0.740±0.030) mL in the pancreatic tissue of rats in simple sham injury group within 1 h immediately after injury, the (0.823±0.033) mL in sham injury+CCK8 group was significantly increased (t=4.92, P<0.05). Compared with that of rats in sham injury+CCK8 group immediately after injury, the PBJ secretory volume of rats within 1 h in severe scald+CCK8 group ((0.681±0.024), (0.608±0.056), (0.525±0.025), and (0.720±0.044) mL) and extremely severe scald+CCK8 group ((0.540±0.025), (0.406±0.021), (0.475±0.036), and (0.690±0.018) mL) was significantly decreased on 1, 2, 3, and 7 days after injury (P<0.05). Compared with that in severe scald+CCK8 group, the PBJ secretory volume of rats within 1 h in extremely severe scald+CCK8 group was significantly decreased on 1 and 2 days after injury (P<0.05). Compared with that of rats in simple sham injury group immediately after injury, the content of pancreatic lipase, α-amylase, and trypsin in PBJ of rats in sham injury+CCK8 group immediately after injury was significantly increased (with t values of 4.56, 3.30, and 4.99, respectively, P<0.05). Compared with that of rats in sham injury+CCK8 group immediately after injury, the content of pancreatic lipase and α-amylase in PBJ of rats in severe scald+CCK8 group and extremely severe scald+CCK8 group was significantly decreased on 1, 2, 3, and 7 days after injury (P<0.05), the trypsin content in PBJ of rats in extremely severe scald+CCK8 group was significantly decreased on 2 days after injury (P<0.05). Compared with that in severe scald+CCK8 group, the content of pancreatic lipase in PBJ of rats in extremely severe scald+CCK8 group was significantly decreased on 1, 2, and 3 days after injury (P<0.05), and the content of α-amylase and trypsin in PBJ was significantly decreased on 1 and 2 days after injury (P<0.05). There were no statistically significant differences in the activities of pancreatic lipase and α-amylase in serum of rats among the 4 groups at various time points after injury (P>0.05). Compared with that of rats in sham injury+CCK8 group immediately after injury, the levels of IL-1ß in pancreatic tissue of rats in severe scald+CCK8 group on 1, 2, and 3 days after injury and in extremely severe scald+CCK8 group on 1, 2, 3, and 7 days after injury were significantly increased (P<0.05), and the levels of IL-6 in pancreatic tissue of rats in severe scald+CCK8 group and extremely severe scald+CCK8 group were significantly increased on 1, 2, 3, and 7 days after injury (P<0.05). Compared with that in severe scald+CCK8 group, the IL-1ß level in pancreatic tissue of rats in extremely severe scald+CCK8 group was significantly increased on 2 and 3 days after injury (P<0.05), and IL-6 level in pancreatic tissue was significantly increased on 2 days after injury (P<0.05). The expression levels of HIF-1α in pancreatic tissue of rats in simple sham injury group and sham injury+CCK8 group immediately after injury were lower; and compared with that in sham injury+CCK8 group immediately after injury, the expression levels of HIF-1α in pancreatic tissue of rats in the 2 scald groups increased to a certain extent at different time points after injury, and the expression position was transited from the edge of the pancreatic tissue to the whole pancreas, the expression levels of HIF-1α in pancreatic tissue of rats in the 2 scald groups tended to be normal on 7 days after injury. Compared with that in simple sham injury group immediately after injury, the proportion of acinar cell cytoplasm in pancreatic tissue of rats in sham injury+CCK8 group was increased; and with the increase of time after injury, edema, hemorrhage, necrosis, and inflammatory infiltration appeared in pancreatic tissue of rats in the 2 scald groups. Compared with that in severe scald+CCK8 group, the scores of edema, inflammatory cell infiltration, bleeding, and necrosis in pancreatic tissue of rats in extremely severe scald+CCK8 group were increased to varying degrees at various time points after injury, and the scores of pancreatic tissue of rats in the 2 scald groups basically recovered to normal on 7 days after injury. Compared with that in simple sham injury group immediately after injury, the number of enzyme granules in acinar cells of pancreatic tissue of rats in sham injury+CCK8 group was increased, and with the increase of time after injury, the enzyme granules in acinar cells of rats in the 2 scald groups were gradually reduced basically. Conclusions: The exocrine functions of pancreas, such as synthesis and secretion of pancreatic enzymes, are decreased in the early stage in severely scalded rats. And the greater the scalded area, the more significant the decline of pancreatic exocrine function. This change may be related to hypoxic injury and inflammation in pancreatic tissue after severe scald.
Subject(s)
Burns , Interleukin-6 , Rats , Male , Animals , Rats, Sprague-Dawley , Trypsin , Edema , Necrosis , Lipase , alpha-AmylasesABSTRACT
The clinical data of maintenance hemodialysis (MHD) patients from twenty hemodialysis centers in Guizhou province from June to September 2020 were collected by cross-sectional study. The patients were divided into AFD group and non-AFD group according to whether AFD had occurred. LTI was measured by body composition monitor. The results showed that the incidence of AFD in 2 781 MHD patients was 30.0% (835/2 781). Median LTI level was 15.2 (13.2, 17.5) kg/m2. The LTI level in the AFD group was higher than that in the non-AFD group (P < 0.05). According to the tertiles of LTI, low LTI group (LTI ≤ 13.9 kg/m2) had the highest incidence of AFD (35.5%, 334/940), and the high LTI group had the lowest incidence of AFD (26.3%, 241/916), and the difference among the three groups was statistically significant (χ2=20.182,P < 0.001). Multivariate logistic regression analysis showed that low LTI group as the reference, the risk of AFD in moderate LTI group (13.9 kg/m2 < LTI ≤ 16.6 kg/m2) and high LTI group were associated with the 20.0% (OR=0.800, 95% CI 0.650-0.986, P=0.036) and 22.8% (OR=0.772, 95% CI 0.616-0.966, P=0.024) decrease, respectively. These results suggest that low LTI level is independently associated with an increased risk of AFD in MHD patients.
Subject(s)
Body Composition , Renal Dialysis , Humans , Cross-Sectional Studies , Renal Dialysis/adverse effectsABSTRACT
As one of the most polluted provinces in China, air pollution events occur frequently in Shandong. Based on the hourly (or daily) concentrations of six air pollutants (PM2.5, PM10, O3, NO2, SO2 and CO), the situations of air quality improvement in three kinds of cities (key cities, coastal cities and general cities) are assessed comprehensively during 2014-2020. Contrary to the daily maximum 8-h average ozone (MDA8 O3), the annual average concentrations of other pollutants show the downward trends during 2014-2020. Therein, the improvement rates of annual average concentrations of air pollutants in key cities are highest. By 2020, the day proportions of O3 as the primary pollutant are up to 38% in three kinds of cities. Besides, due to the impact of COVID-19, the monthly average concentrations of PM2.5, PM10, NO2, SO2 and CO in February 2020 decrease by 32.1-49.5% year-on-year. There are still about 50% of population exposed to high-risk regions (R i > 2), which are mainly concentrated in main urban areas and industrial areas. Thus, the adjustment of industrial structure and energy composition in the context of carbon peak and carbon neutrality should be implemented in the future. Supplementary Information: The online version contains supplementary material available at 10.1007/s13762-022-04651-5.
Subject(s)
Hepatoblastoma , Liver Neoplasms , Aged , Female , Humans , Liver Neoplasms/surgery , Tomography, X-Ray ComputedABSTRACT
Gastric cancer (GC) is a major digestive tract malignancy in China, which seriously threatens the health of Chinese population. A large number of researches have demons-trated that screening, early detection and early treatment are effective in reducing the incidence and mortality of GC. The development of the guideline for GC screening, early detection and early treatment in line with epidemic characteristics of GC in China will greatly promote the homogeneity and standardization, and improve the effect of GC screening. This guideline was commissioned by the Bureau of Disease Control and Prevention of the National Health Commission. The National Cancer Center of China initiated and convened a working group comprising multidisciplinary experts. Following the World Health Organization Handbook for Guideline Development, this guideline combined the most up-to-date evidence of GC screening, China's national conditions, and practical experience in cancer screening. This guideline provided evidence-based recommendations with respect to the screening population, technology and procedure management, aiming to improve the effect of GC screening and provide scientific evidence for the GC prevention and control in China.
Subject(s)
Early Detection of Cancer , Stomach Neoplasms , Beijing , China/epidemiology , Early Detection of Cancer/methods , Humans , Mass Screening , Stomach Neoplasms/diagnosis , Stomach Neoplasms/prevention & controlABSTRACT
OBJECTIVE: To explore the feasibility of preparing compound tablets for the treatment of hypertension by fused deposition modeling (FDM) 3D printing technology and to evaluate the quality of the printed compound tablets in vitro. METHODS: Polyvinyl alcohol (PVA) filaments were used as the exci-pient to prepare the shell of tablet. The ellipse-shaped tablets (the length of major axes of ellipse was 20 mm, the length of the minor axes of ellipse was 10 mm, the height of tablet was 5 mm) with two separate compartments were designed and printed using FDM 3D printer. The height of layer was 0.2 mm, and the thickness of roof or floor was 0.6 mm. The thickness of shell was 1.2 mm, and the thickness of the partition wall between the two compartments was 0.6 mm. Two cardiovascular drugs, captopril (CTP) and hydrochlorothiazide (HCT), were selected as model drugs for the printed compound tablet and filled in the two compartments of the tablet, respectively. The microscopic morphology of the tablets was observed by scanning electron microscopy (SEM). The weight variation of the tablets was investigated by electronic scale. The hardness of the tablets was measured by a single-column mechanical test system. The contents of the drugs in the tablets were determined by high performance liquid chromatography (HPLC), and the dissolution apparatus was used to measure the in vitro drug release of the tablets. RESULTS: The prepared FDM 3D printed compound tablets were all in good shape without printing defects. The average weight of the tablets was (644.3±6.55) mg. The content of CTP and HCT was separately (52.3±0.26) mg and (49.6±0.74) mg. A delayed in vitro release profile was observed for CTP and HCT, and the delayed release time for CTP and HCT in vitro was 20 min and 40 min, respectively. The time for 70% of CTP and HCT released was separately 30 min and 60 min. CONCLUSION: CTP and HCT compound tablets were successfully prepared by FDM 3D printing technology, and the printed tablets were of good qualities.
Subject(s)
Captopril , Hydrochlorothiazide , Cytidine Triphosphate , Drug Liberation , Printing, Three-Dimensional , Tablets/chemistry , Technology, Pharmaceutical/methodsABSTRACT
Despite the high capacity and low cost of lithium-sulfur (Li-S) batteries, their commercialization is greatly blocked by multiple bottlenecks including the shuttle effect of lithium polysulfides (LiPSs), poor conductivity of sulfur, and sluggish reaction kinetics. Herein, we propose novel two-dimensional MSi2P4 (M = V, Nb, and Ta) monolayers as promising sulfur hosts to improve the Li-S battery performance. Our calculations show that MSi2P4 monolayers offer moderate binding strengths to the polysulfides, which are expected to effectively inhibit the LiPS shuttling and dissolution. Moreover, the conductive properties of the MSi2P4 systems are well maintained after LiPS adsorption, eliminating the insulating nature of sulfur species. Remarkably, MSi2P4 monolayers exhibit superior electrocatalytic activity for the sulfur reduction reaction and the Li2S decomposition reaction, which considerably lowers the energy barriers of LiPS conversions during discharge and charge, thus ensuring the fast redox kinetics and high sulfur utilization of Li-S batteries. This study pioneers the application of MSi2P4 monolayers as highly efficient sulfur host materials for Li-S batteries and affords insights for further development of advanced Li-S batteries.
ABSTRACT
Esophageal cancer (EC) is a major digestive tract malignancy in China, which seriously threatens the health of Chinese population. A large number of researches have demonstrated that screening and early detection are effective in reducing the incidence and mortality of EC. The development of the guideline for EC screening and early detection in line with epidemic characteristics of EC in China will greatly promote the homogeneity and standardization, and improve the effect of EC screening. This guideline was commissioned by the Bureau of Disease Control and Prevention of the National Health Commission. The National Cancer Center of China initiated and convened a working group comprising multidisciplinary experts. Following the World Health Organization Handbook for Guideline Development, this guideline combined the most up-to-date evidence of EC screening, China's national conditions, and practical experience in cancer screening. This guideline provided evidence-based recommendations with respect to the screening population, technology and procedure management, aiming to improve the effect of EC screening and provide scientific evidence for the EC prevention and control in China.
Subject(s)
Early Detection of Cancer , Esophageal Neoplasms , Beijing , China/epidemiology , Early Detection of Cancer/methods , Esophageal Neoplasms/diagnosis , Esophageal Neoplasms/prevention & control , Humans , Mass ScreeningABSTRACT
Hepatocellular carcinoma (HCC) caused by hepatitis B virus (HBV) is the first cause of cancer-caused death in China. This study, from the perspective of HBV genomic epidemiology, systematically investigated the evolution of HBV and their interaction with host genetic factors in each stage of HBV carcinogenesis and comprehensively analyzed the role of apolipoprotein B mRNA editing enzyme catalytic polypeptides (APOBEC) family in the inflammation-to-cancer transformation. Based on our findings and related studies, we proposed "cancer evolution and development" (Cancer Evo-Dev) theoretical system suitable for most cancer types. Cancer Evo-Dev lays a theoretical foundation for understanding the mechanism of inflammation to promote the development of cancer, which is of great significance for the specific prevention, prediction, early diagnosis, and targeted therapy of malignant diseases.
Subject(s)
Carcinoma, Hepatocellular , Hepatitis B , Liver Neoplasms , Carcinoma, Hepatocellular/genetics , China , Hepatitis B/complications , Hepatitis B/genetics , Hepatitis B virus/genetics , Humans , Liver Neoplasms/genetics , MutationABSTRACT
Objective: To investigate the rule of mediastinal lymph node metastasis of papillary thyroid carcinoma and the application of therapeutic mediastinal lymph node dissection through the sternotomy approach in the treatment of mediastinal lymph node metastasis of papillary thyroid carcinoma. Methods: All cases of papillary thyroid carcinoma with mediastinal lymph node metastasis treated through sternotomy cooperated by thoracic surgeons and head and neck surgeons from January 2006 to January 2017 in Cancer Hospital of Chinese Academy of Medical Sciences were included in this study. The distribution, metastasis rate, metastasis degree, surgical method, surgical complications and postoperative survival of patients with mediastinal lymph node metastasis were retrospectively analyzed. Results: A total of 31 patients (16 males and 15 females) with papillary thyroid cancer with mediastinal lymph node metastasis, with a median age of 46 (19-65) years, were enrolled in the group. Partial upper sternotomy was used in 28 cases, and total sternotomy was used in 3 cases. The mediastinal lymph nodes of papillary thyroid carcinoma metastasized farthest to the station 6, and the lymph node metastasis rate of each group from high to low was: 2R (61%), 1R (39%), 3A (39%), 1L (16%), 2L (10%), 4R (10%), 5 (3%) and 6 (3%). No metastasis was observed in station 3P, 4L and 7. In addition, the degree of lymph node metastasis at station 2R was the highest, reaching 35% (77/219). Extra-nodal invasion of mediastinal metastatic lymph nodes in thyroid papillary carcinoma is common (23%), easily fuses into masses (23%) and invades peripheral vascular nerves (26%). Up to 29% of blood transfusions are required during or after surgery due to oozing or bleeding (9/31). The 1-, 3-, 5-and 10-year survival rates of patients undergoing surgical treatment were 94%, 94%, 87% and 81%, respectively. Conclusion: Papillary thyroid carcinoma can metastasize to almost all mediastinal lymph nodes except station 3P, 4L and 7. Radical mediastinal lymph node dissection through sternotomy is an effective method for the treatment of mediastinal lymph node metastasis of thyroid papillary carcinoma.
Subject(s)
Carcinoma, Papillary , Thyroid Cancer, Papillary , Thyroid Neoplasms , Aged , Female , Humans , Lymph Node Excision , Lymph Nodes , Male , Middle Aged , Neck Dissection , Retrospective Studies , Sternotomy , ThyroidectomyABSTRACT
Lidocaine, a typical local anesthetic, has been shown to directly induce neurotoxicity in clinical settings. Dexmedetomidine (DEX) is an alpha-2-adrenoreceptor agonist that has been used as anxiolytic, sedative, and analgesic agent which has recently found to protect against lidocaine-induced neurotoxicity. Nicotinamide adenine dinucleotide-dependent deacetylase sirtuin-1 (SIRT1)/forkhead box O3 (FOXO3a) signaling is critical for maintaining neuronal function and regulation of the apoptotic pathway. In the present study, we designed in vitro and in vivo models to investigate the potential effects of lidocaine and DEX on SIRT1 and FOXO3a and to verify whether SIRT1/FOXO3a-mediated regulation of apoptosis is involved in DEX-induced neuroprotective effects against lidocaine. We found that in both PC12 cells and brains of mice, lidocaine decreased SIRT1 level through promoting the degradation of SIRT1 protein. Lidocaine also increased FOXO3a protein level and increased the acetylation of SIRT1 through inhibiting SIRT1. Upregulation of SIRT1 or downregulation of FOXO3a significantly inhibited lidocaine-induced changes in both cell viability and apoptosis. DEX significantly inhibited the lidocaine-induced decrease of SIRT1 protein level and increase of FOXO3a protein level and acetylation of FOXO3a. Downregulation of SIRT1 or upregulation of FOXO3a suppressed DEX-induced neuroprotective effects against lidocaine. The data suggest that SIRT1/FOXO3a is a potential novel target for alleviating lidocaine-induced neurotoxicity and provide more theoretical support for the use of DEX as an effective adjunct to alleviate chronic neurotoxicity induced by lidocaine.
Subject(s)
Anesthetics, Local/toxicity , Dexmedetomidine/pharmacology , Forkhead Box Protein O3/antagonists & inhibitors , Lidocaine/antagonists & inhibitors , Neuroprotective Agents/pharmacology , Sirtuin 1/antagonists & inhibitors , Acetylation , Animals , Apoptosis/drug effects , Cell Survival , Down-Regulation/genetics , Forkhead Box Protein O3/genetics , Forkhead Box Protein O3/metabolism , Lidocaine/toxicity , Mice , Mice, Inbred C57BL , PC12 Cells , RNA, Small Interfering/genetics , Rats , Sirtuin 1/genetics , Sirtuin 1/metabolismABSTRACT
Nitrite is a common toxic substance in culture systems of Litopenaeus vannamei, and the stress may disturb hemocyanin synthesis and energy metabolism and result in shrimp death. In the present study, nitrite at concentrations of 0 (control), 3.3 (46.2 NO2-N mg/L), 6.6 (92.4) and 9.9â¯mM (138.6) was used to evaluate the responses of hemocyanin level and energy metabolism in L. vannamei (5.80⯱â¯0.44â¯cm, 1.88⯱â¯0.38â¯g) for 96â¯h. The mortality rate at 96â¯h increased with nitrite concentration (50% at 9.9â¯mM, 40% at 6.6â¯mM, 30% at 3.3â¯mM, and 10% at 0â¯mM). In general, HIF-1α and hemocyanin mRNA expression in the nitrite stress groups was upregulated from 6 to 12â¯h and downregulated from 24 to 96â¯h. In the hemolymph, nitrite levels were significantly elevated in a dose-dependent manner, and exposure to nitrite stress significantly decreased the oxyhemocyanin content from 24 to 96â¯h. The glucose and lactate levels in the hemolymph in the nitrite stress groups were higher than those in the control group from 12 to 96â¯h. Compared with the control group, the shrimp in the nitrite stress groups exhibited decreased glycogen concentrations in the hepatopancreas. The triglyceride (TG) levels in the nitrite stress groups were all higher than those in the control group from 48 to 96â¯h. The hexokinase (HK) activity in the hepatopancreas and muscle increased in the nitrite stress groups from 48 to 96â¯h. In general, nitrite stress enhanced the activities of pyruvate kinase (PK), phosphofructokinase (PFK) and lactate dehydrogenase (LDH) in muscle from 24 to 96â¯h. In addition, nitrite stress decreased the activities of succinate dehydrogenase (SDH) and fatty acid synthase (FAS) from 24 to 96â¯h in the hepatopancreas and muscle. This study indicates that exposure to nitrite stress can enhance the accumulation of nitrite in the hemolymph and then reduce oxygenation and hemocyanin synthesis, leading to tissue hypoxia and thereby resulting in accelerated anaerobic metabolism and the inhibition of aerobic metabolism. The effects of nitrite stress on hemocyanin synthesis and energy metabolism may be one of the reasons for the mortality of L. vannamei in culture systems.