[How to think about the clinical classifications of acquired aplastic anemia]

Paying attention to the diagnosis and classification of acquired aplastic anemia (AA) is the basis for improving the efficacy and the guarantee for the correct exploration of the pathological mechanism, which is of great clinical and academic significance. At present, AA classification is still based on clinical characteristics, which is a historical product of academic development.It is beneficial to guide symptomatic treatment and for the onset of curative treatment. However, the clinical classification of AA cannot replace the pathological mechanism classification to guide the treatment of the root cause. The classification of the pathological mechanism of AA determines the choice of treatment strategy, and can provide a basis for the study of etiology and prevention, and is also the future research direction. Paying attention to the classification of the pathological mechanism of AA is the basis for improving the efficacy and the guarantee for the correct exploration of the pathological mechanism. Modern medicine has entered the era of "molecular targets" and "precision", and how to treat clinical classification based on clinical characteristics is an important issue faced by clinicians. When many different mechanisms of bone marrow failure isolated from AA patients can be accurately identified, that is, when the clinically diagnosed AA has been truly purified into a disease with a clear pathological mechanism, the clinical classification of AA can help to choose the root cause strategy. This article mainly focuses on how to view the clinical classification of AA for the reference of colleagues.

[Evaluation of the efficacy and safety of intravenous infusion of ferric derisomaltose in the treatment of iron deficiency anemia: a single-center retrospective analysis]

Objective: To investigate the clinical efficacy and safety of ferric derisomaltose injection versus iron sucrose injection in the treatment of iron deficiency anemia (IDA) . Methods: A total of 120 patients with iron deficiency anemia admitted from June 2021 to March 2023 were given intravenous iron supplementation with ferric derisomaltose to assess the efficacy and safety of hemoglobin (HGB) elevation before and after treatment. Simultaneously, the clinical effects of iron supplementation with iron sucrose were compared to those of inpatient patients during the same period. Results: Baseline values were comparable in both groups. Within 12 weeks of treatment, the elevated HGB level in the ferric derisomaltose group was higher than that of the iron sucrose group, with a statistical difference at all time points, and the proportion of HGB increased over 20 g/L in the patients treated for 4 weeks was higher (98.7%, 75.9% ). During the treatment with ferric derisomaltose and iron sucrose, the proportion of mild adverse reactions in the ferric derisomaltose group was slightly lower than that of the iron sucrose group, and neither group experienced any serious adverse reactions. The patients responded well to the infusion treatment, with no reports of pain or pigmentation at the injection site. Conclusion: The treatment of IDA patients with ferric derisomaltose has a satisfactory curative effect, with the advantages of rapidity, accuracy, and safety. Therefore, it is worthy of widespread clinical use.

[Efficacy and safety of pegylated interferon alpha-2b for patients with myeloproliferative neoplasm]

Objective: To evaluate the efficacy and safety of pegylated interferon alpha-2b (PEG-IFN-α2b) in the treatment of myeloproliferative neoplasm (MPN). Methods: Thirty-four MPN patients receiving PEG-IFN-α2b treatment in the Second Hospital of Tianjin Medical University from August 2019 to October 2022 were prospectively included. Among the patients, 9 were male and 25 were female, and the median age [M (Q1, Q3)] was 57 (19, 78) years. Patients' clinical characteristics were collected and the follow-up was performed. As of January 30, 2023, the follow-up period [M(Q1, Q3)] was 24 (16, 33) months. The efficacy, safety and changes in immune cell and cytokine levels after 12 and 24 months of treatment were analyzed. Results: During the follow-up period, 4 patients dropped out, and the efficacy was evaluable in 30 patients. Following 12 and 24 months of treatment, the complete hematologic response (CHR) rates were 57.1% (16/28) and 75.0% (18/24), respectively. The complete molecular response (CMR)+partial molecular response (PMR) rates were 27.3% (6/22) and 55.0% (11/20), respectively. The bone marrow histopathological overall response rates (ORR) were 34.6% (9/26) and 47.6% (10/21), respectively. At 12 and 24 months of treatment, the proportions of CD8+HLA-DR+T cells, effector T cell subpopulations, CD56bright natural killer (NK) cells, and plasmacytoid dendritic cells (pDC) were higher than the pre-treatment levels, while the proportion of CD56dim NK cells was lower than the pre-treatment level (all P<0.05). The levels of motif chemokine ligand 10 (CXCL10), tumor necrosis factor (TNF)-α and TNF-β in bone marrow all increased from those prior to treatment, while the levels of vascular endothelial growth factor (VEGF) and interleukin (IL-4) decreased from those prior to treatment (all P<0.05). Among hematological adverse reactions, white blood cells decrease [47% (16/34)] was observed with high incidence. Among non-hematological adverse reactions, asthenia [44.1% (15/34)] and transaminases increase [32.3% (11/34)] were observed with high incidences. Conclusions: PEG-IFN-α2b has high hematologic, molecular, and bone marrow histopathological response rates in the treatment of MPN. It can reduce malignant clone loads and regulate the immune microenvironment and is safe and well tolerated overall.

[Research status and challenges of advanced myeloproliferative neoplasms]

Classical myeloproliferative neoplasms (MPN), also known as Ph-MPN, includes polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). Secondary myelofibrosis (sMF) and secondary acute myeloid leukemia (sAML) are important disease progressions of MPN. After MPN disease progression, hematopoietic stem cells undergo new clonal evolution, leading to drug resistance, poor treatment effect and poor survival of patients. In recent years, the exploration of the mechanism of disease progression and the precise diagnosis and treatment of MPN have attracted much attention. This article summarizes the research status of MPN disease progression, including the pathogenesis, risk stratification, and precision treatment, in order to provide reference for exploring new diagnosis and treatment methods of MPN disease progression.

[Analysis of risk factors for thromboembolism in patients with JAK2V617F gene mutation positive myeloproliferative neoplasms]

Objective: To analyze the risk factors of thrombosis in patients with JAK2V617F mutation positive myeloproliferative neoplasms (MPN). Methods: A total of 223 MPN patients with JAK2V617F mutation in the Second Hospital of Tianjin Medical University from September 2017 to May 2023 were retrospectively enrolled, including 111 males and 112 females, aged [M(Q1,Q3)] 57(21,66) years. According to the presence or absence of thromboembolism during follow-up, the patients were divided into thrombosis group (n=102) and non-thrombosis group (n=121). The clinical characteristics, laboratory characteristics, cytogenetics and other disease progression and survival of the two groups of patients were analyzed. As of March 31, 2023, the follow-up period [M (Q1, Q3)] was 6 (3, 10) years. The influencing factors of thrombosis in JAK2V617F positive MPN patients were analyzed by using the Cox risk model. Results: Among 223 JAK2V617F positive MPN patients, 144 were polycythemia vera (PV), 51 were essential thrombocythemia (ET) and 28 were primary myelofibrosis (PMF). The mutation rates of ASXL1 and BCORL1 genes in the thrombosis group were 19.6% (20/102) and 6.9% (7/102), respectively, which were higher than those in the non-thrombosis group [9.1% (11/121) and 0.8% (1/121)] (both P<0.05). The proportion of monocytes, C-reactive protein (CRP), interleukin-1β (IL)-1β, IL-8 and tumor necrosis factor-β (TNF-β) increased in the thrombosis group were higher than those in the non-thrombosis group (all P<0.05). Multivariate analysis showed that age≥60 years (HR=2.132, 95%CI: 1.376-3.303, P=0.001), history of thrombosis (HR=3.636, 95%CI: 2.121-6.202, P<0.001), ASXL1 mutation positive (HR=2.245, 95%CI: 1.093-3.231, P=0.022) and elevated TNF-β (HR=2.009, 95%CI: 1.113-3.624, P=0.021) were risk factors for thrombosis in JAK2V617F positive MPN patients. Conclusions: In addition to age, history of thrombosis and positive ASXL1 mutation, elevated TNF-β is also an influencing factor of thrombosis in JAK2V617F positive MPN patients. Intervention of inflammation may have a certain effect on the prevention and treatment of thrombosis.

[Clinical and laboratory features of SF3B1-mutated myeloproliferative neoplasms]

Objective: To explore the clinical and laboratory characteristics of SF3B1 gene mutations in myeloproliferative neoplasms (MPN) patients. Methods: The clinical data of 273 MPN patients who were diagnosed MPN and treated in the Second Hospital of Tianjin Medical University from November 2017 to March 2023 were retrospectively analyzed. There were 133 males and 140 females, with a median age M(Q1,Q3)of 56(46, 67) years. The molecular biology and cytogenetic characteristics were detected by second-generation sequencing (NGS) and R+G banding techniques, and the clinical and laboratory characteristics of patients with SF3B1 gene mutation were analyzed. Results: SF3B1 gene mutations were found in 13 patients (4.8%, 13/273).The types of SF3B1 mutations included missense (92.3%, 12/13) and nonsense mutations (7.7%, 1/13).Compared to the non-mutant cohort, patients in SF3B1 mutant cohort had older ages [68(51, 76) vs 56(45, 66)years,P=0.025], higher proportion of splenomegaly [46.2%(6/13) vs 15.8%(41/259),P=0.014]and secondary tumor [23.1%(3/13)vs 3.8%(10/260), P=0.018]with higher proportion of bone marrow blast [0.5%(0, 1.5%) vs 0(0, 0.5%),P=0.002] and lower hemoglobin[(104±36) vs (137±40) g/L,P=0.004] and hematocrit [31%(22%, 40%) vs 41%(35%, 52%),P=0.003]. All of the 10 patients in the SF3B1 mutant cohort whose ring sideroblast (RS) could be evaluated showed no RS formation. The overall survival, thrombosis-free survival and leukemia free survival of MPN patients in SF3B1 mutant cohort were 4.0 (2.0, 6.0), 2.0 (0.5, 4.5) and 4.0 (2.0, 6.0) years, respectively, while patients in the non-mutant cohort were 6.0 (3.0, 10.0), 5.0 (1.0, 8.0), 6.0 (3.0, 10.0) years, respectively, there were no statistical significance between two groups (Z=3.69, 1.66, 2.05, all P>0.05).The secondary tumor free survival of SF3B1 mutant cohort patients was 4.0 (2.0, 6.0) years, which was lower than that of non-mutant cohort patients [5.5 (3.0, 10.0) years, Z=18.18, P<0.001). Conclusions: MPN patients with SF3B1 gene mutations are older, more prone to splenomegaly and secondary tumors. They also have a higher proportion of bone marrow blast, lower hemoglobin and hematocrit, and show no RS formation.

[Review and perspective of clinical research involving chest tightness variant asthma in China]

Chest tightness variant asthma (CTVA) was first reported and named by Chinese scholars in 2013. It is a new clinical type of asthma characterized by chest tightness as the only or primary symptom, without typical asthma manifestations such as recurrent wheezing and shortness of breath, and without wheezing sounds heard during lung auscultation. The overall epidemiological data on CTVA is currently unavailable. Its pathogenesis is similar to that of typical asthma, involving eosinophilic airway inflammation. Due to the lack of typical clinical manifestations, insufficient knowledge of this disease in some clinicians and some other reasons, CTVA is susceptible to misdiagnosis or missed diagnosis. Currently, the diagnostic criteria for CTVA are: chest tightness as the only or primary symptom, without typical asthma symptoms and signs such as wheezing and shortness of breath, and with any one of the objective indicators of variable airflow limitation. Effective anti-asthma treatment is required, and other diseases that cause chest tightness, such as cardiovascular, digestive, nervous, muscular, and mental diseases should be excluded. CTVA treatment follows that of typical asthma, but the specific treatment duration is uncertain and may require long-term management. Traditional Chinese medicine has shown some therapeutic effects on CTVA. Most CTVA patients have a good prognosis after active anti-asthma treatment. This paper analyzes and summarizes the research of CTVA in China from 2013 and provides new perspectives for further exploration of CTVA.

[The expression and correlation analysis of TOX and inhibitory receptors on peripheral blood CD8+T cells in patients with aplastic anemia]

Objective: To investigate the expression levels of thymocyte selection related high mobility group proteins (TOX) and different inhibitory receptors in peripheral blood CD8⁺T cells of patients with aplastic anemia (AA), and to conduct correlation analysis. Methods: From September 2019 to November 2020, 27 AA patients in the Department of Hematology, General Hospital of Tianjin Medical University were retrospectively selected, including 21 males and 6 females, with a median age [M (Q₁, Q₃)] of 48 (30, 72) years. Thirty-three healthy controls, included 17 males and 16 females, with a median age of 46 (27, 69) years. The expression levels of TOX, programmed cell death receptor-1 (PD-1), T-cell immunoglobulin and mucin domain 3 (TIM-3), cytotoxic T-lymphocyte associated antigen-4 (CTLA-4), T-cell immune receptor with immunoglobulin (Ig) and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT), perforin and granzyme B in peripheral blood CD8⁺T cells from AA patients and healthy controls were detected by flow cytometry. The correlation between TOX expression levels and different inhibitory receptors was analyzed using Pearson correlation analysis. Results: The expression levels of TOX, PD-1, TIM-3, CTLA-4, TIGIT, perforin, and granzyme B in peripheral blood CD8⁺T cells of AA patients were 47.33%(41.47%, 56.61%), (30.61±12.37)%, (39.94±10.84)%, (6.21±3.40)%, (51.45±20.21)%, (71.32±22.46)%, and (52.39±23.99)%, respectively, which were higher than those of healthy controls 27.32%(21.64%, 46.96%), (21.29±10.01)%, (21.11±3.00)%, (1.31±0.34)% (30.80±13.40)%, (46.72±22.53)%, (21.75±16.43)% (all P<0.05). The expression level of TOX in CD8⁺T cells was positively correlated with the expression levels of PD-1, TIM-3, CTLA-4, TIGIT, perforin, and granzyme B (r=0.49, 0.65, 0.70, 0.54, 0.58, 0.48, all P<0.05). Conclusion: The expression levels of TOX and different inhibitory receptors on peripheral blood CD8⁺T cells in AA patients are higher than those in the healthy control group, and the expression levels of TOX and different inhibitory receptors are positively correlated.

[Role and clinical significance of MUC4 gene mutations in thrombotic events in patients with classic paroxysmal nocturnal hemoglobinuria]

Objective: This study aimed to investigate the role and clinical significance of MUC4 gene mutations in thrombotic events in patients with classic paroxysmal nocturnal hemoglobinuria (PNH) patients. Methods: A retrospective analysis was conducted on the clinical data and gene sequencing results of 45 patients with classic PNH admitted to the Department of Hematology, Tianjin Medical University General Hospital, from June 2018 to February 2022. MUC4 gene mutations in patients with classic PNH were summarized, and the risk factors for thrombotic events in these patients were analyzed. Additionally, the effects of MUC4 gene mutations on the cumulative incidence and survival of thrombotic events in patients with classic PNH were determined. Results: The detection rate of MUC4 gene mutations in patients with classic PNH who experienced thrombotic events (thrombotic group) was 68.8% (11/16), which was significantly higher than that in the non-thrombotic group [10.3% (3/29) ] (P<0.001). All mutations occurred in exon 2. MUC4 mutation (OR=20.815, P=0.010) was identified as an independent risk factor for thrombotic events in patients with classic PNH. The cumulative incidence of thrombotic events was 78.6% (11/14) in the MUC4 gene mutation group (mutation group) and 16.1% (5/31) in the non-mutation group, showing a statistically significant difference between the two groups (P<0.001). Survival analysis showed a lower overall survival (OS) rate in the thrombotic group compared with that in the non-thrombotic group [ (34.4±25.2) % vs. (62.7±19.3) % ] (P=0.045). The OS rate of patients was (41.7±29.9) % in the mutation group and (59.1±18.3) % in the non-mutation group (P=0.487) . Conclusion: MUC4 gene mutations are associated with an increased incidence of thrombotic events in classic PNH patients, highlighting their role as independent risk factors for thrombosis in this population. These mutations can be considered a novel predictive factor that aids in evaluating the risk of thrombosis in patients with classic PNH.

[Abnormal expression of CXCR5+CD8+ T cells and CXCL13 in severe aplastic anemia patients and their correlation with hematological parameters]

Objective: To analyze the expression of C-X-C chemokine receptor 5 (CXCR5)⁺CD8⁺ T cells and plasma C-X-C motif chemokine 13 (CXCL13) in severe aplastic anemia (SAA) patients and their correlations with hematological parameters. Methods: The clinical data of 35 SAA patients in the Hematology Department of Tianjin Medical University General Hospital from January 2018 to September 2021 were retrospectively analyzed. The patients were divided into two groups according to whether they had received the medication: untreated SAA group and recovery SAA group. In untreated group, there were 18 patients who had not received any medication, with 9 males and 9 females, and aged 51 (18-76) years. In recovery SAA group, there were 17 patients who were separated from component blood transfusion after the immunosuppressive treatment with anti-thymocyte globulin (ATG) combined with cyclosporine A (CsA), with 7 males and 10 females, and aged 46 (16-70) years. Meanwhile, 20 healthy controls were also selected, including 8 males and 12 females, and aged 45(15-72) years. Peripheral blood and bone marrow samples were collected from SAA patients, while peripheral blood samples were obtained from healthy controls. Flow cytometry was used to detect the percentage of CXCR5⁺CD8⁺ T cells in peripheral blood and bone marrow samples. The concentration of plasma CXCL13 was measured by enzyme-linked immunosorbent assay (ELISA). The correlations between the percentage of CXCR5⁺CD8⁺ T cells and the concentration of CXCL13, as well as the correlations between these two parameters and the hematological parameters were analyzed by Spearman correlation analysis. Results: The proportion of CXCR5⁺CD8⁺ T cells in the bone marrow of untreated SAA group was (4.9±2.9)%, which was higher than that of recovery SAA group (2.7±1.5)%, with a statistically significant difference (t=2.34, P=0.027). The proportion of CXCR5⁺CD8⁺ T cells in peripheral blood of untreated SAA group, recovery SAA group and healthy control group was (8.4±4.2)%, (3.8±2.3)% and (2.6±2.0)% respectively. The proportion of CXCR5⁺CD8⁺ T cells in peripheral blood of untreated SAA group was higher than that of recovery SAA group and healthy control group (both P<0.05). The plasma CXCL13 concentration in untreated SAA group was (97.2±46.8) ng/L, which was significantly higher than that in recovery SAA group [(54.9±20.9) ng/L] and healthy control group [(47.6±17.3) ng/L] (both P<0.05). The proportion of CXCR5⁺CD8⁺ T cells in peripheral blood of SAA patients was positively correlated with the concentration of plasma CXCL13 (r=0.545, P<0.001). The proportion of peripheral blood CXCR5⁺CD8⁺ T cells in SAA patients was negatively correlated with white blood cell count, platelets count, percentage of neutrophils, absolute neutrophils count, percentage of reticulocytes, absolute reticulocytes count, bone marrow myeloid cells, bone marrow erythroid cells and megakaryocytes count (r=-0.556, -0.392, -0.617, -0.615, -0.395, -0.543, -0.432, -0.484 and -0.523, all P<0.05). The proportion of peripheral blood CXCR5⁺CD8⁺ T cells was positively correlated with the percentage of peripheral blood lymphocytes and bone marrow lymphoid cells (r=0.593 and 0.556, both P<0.05). Meanwhile, the concentration of plasma CXCL13 in SAA patients was negatively correlated with white blood cell count, absolute neutrophils count, percentage of reticulocytes, absolute reticulocytes count and bone marrow myeloid cells (r=-0.447, -0.446, -0.498, -0.407 and -0.456, all P<0.05), but positively correlated with bone marrow lymphoid cells (r=0.384, P<0.05). Conclusions: The proportion of CXCR5⁺CD8⁺ T cells and the concentration of plasma CXCL13 increases in SAA patients. The proportion of CXCR5⁺CD8⁺ T cells in peripheral blood is positively correlated with the concentration of CXCL13. Moreover, the proportion of CXCR5⁺CD8⁺ T cells and the concentration of CXCL13 are correlated with many hematological parameters, which may play a critical role in the immune pathogenesis of SAA.

[Effect and prognosis of new type of re-dilated stent in the treatment of pulmonary artery bifurcation stenosis]

the early and med-term follow-up results and technical points of new re-dilated stent in the treatment of pulmonary artery bifurcation opening stenosis, and explore its feasibility and advantages. From March 2019 to October 2020, 10 children [5 males, mean age (7±3) years], mean weight 18.75(13.35,23.05) kg with pulmonary artery bifurcation opening stenosis were treated with new re-dilated stents in the Central China Fuwai Hospital. Including 5 cases of tetralogy of Fallot, 4 cases of pulmonary atresia, 1 case of anomalous origin of coronary artery, all children were given new re-dilated stent implantation. Echocardiography, chest X-ray and electrocardiogram were performed 1 day, 3, 6, 12 months after intervention. Pulmonary artery CTA was performed after 6 or 12 months to evaluate the results, including restenosis, malposition and rupture. A total of 16 stents were implanted in 10 children, 5 cases had simultaneous stenosis of bifurcation openings of pulmonary arteries, and 1 stent was implanted in each of the left and right pulmonary artery openings. The pressure of right ventricular and gradient was significantly decreased immediately after intervention, from preoperative (38-80) mmHg(1 mmHg=0.133 kPa) to postoperative (0-22) mmHg, only one patient's pressure gradient is over 20 mmHg (22 mmHg), and all cases discharged successfully. Stent restenosis, malposition, fracture and other abnormalities were not observed in follow-up. Stents implantation for patients with pulmonary artery bifurcation opening stenosis is very more difficult. A good strategy can ensure that the intervention is safe and effective. It not only avoids the risk of repeated surgery, but also achieves good med-term follow-up results.

[Exclusive diagnosis of aplastic anemia]

As an independent disease, aplastic anemia (AA) has been recognized for more than a century. When AA is diagnosed, other non-AA bone marrow failures should be excluded. It is termed as exclusive diagnosis of AA. The exclusive diagnosis of AA is helplessly based on that there is no parameter by which AA can be sensitively and specifically diagnosed now. So further searching for the meaningful diagnostic parameters of AA should be carried on to establish a direct diagnostic protocol of this disease and make it possible to differentiate it clearly from other bone marrow failure disease such as congenenital bone marrow failure, hypoplastic myelodysplastic syndromes, AA-paroxysmal nocturnal hemoglobinuria syndromes, large granules lymphocyte leukemia, clonal cytopenia of undetermined significance, immunorelated pancytopenia, acute hemopoietic arresting and idiopathic cytopenia of undetermined significance. The new markers and technologies being helpful for distinguishing AA from other bone marrow failures should be used in diagnosing AA. Correct understanding and application of exclusive diagnosis is not only related to the correctness of diagnosis and treatment of excluded diseases, but also to the quality of AA diagnosis, treatment and research.

[Short- and mid-term outcomes of percutaneous balloon mitral valvuloplasty under the guidance of ultrasound]

Objective: To evaluate the safety, short- and mid-term outcomes of percutaneous balloon mitral valvuloplasty (PBMV) guided by the ultrasound. Methods: In this retrospective study, medical data of 15 patients [9 males and 6 females, with an age of (53±13) years] with PBMV under the guidance of ultrasound in Heart Center of Henan Provincial People's Hospital between December 2016 and January 2019 were collected and reviewed. The short-and mid-term outcomes were analyzed. Results: PBMV was successfully performed in all the patients. One patient underwent surgical valve replacement due to severe mitral regurgitation, and the other 14 patients were all followed up successfully. The average follow-up time was (13.8±4.6) months. Comparisons of preoperative and postoperative data showed significant differences in valve area [(1.84±0.43) cm² vs (0.89±0.24) cm²], left atrial pressure [(11.9±4.5) mmHg (1 mmHg=0.133 kPa) vs (21.9±6.0) mmHg] and mean mitral valve pressure gradient [(10.9±3.2) mmHg vs (20.1±3.6) mmHg](all P<0.01), with no significant differences in mitral regurgitation area (P=0.67). Postoperative follow-up showed that there were no significant differences in mitral valve area, regurgitation area and N-terminal pro-B-type natriuretic peptide (NT-proBNP) between short-and mid-term postoperatively (all P>0.05). There was no secondary operation due to mitral stenosis in 14 patients, and 3 patients with moderate or severe tricuspid regurgitation showed significant improvement, with gradually recovered cardiac function, and there were no deaths in these patients. Conclusion: PBMV guided by the ultrasound is feasible and effective, and exhibits favorable short-and mid-term outcomes.

[Related factors and interaction on hepatitis C virus infection in patients receiving methadone maintenance treatment in Taiyuan]

Objective: To explore the prevalence of hepatitis C virus (HCV) infection, influence factors and interaction on HCV infection in patients receiving methadone maintenance treatment (MMT) in Taiyuan. Methods: Between April-June 2019, three MMT clinics in Taiyuan were selected to conduct a face-to-face questionnaire survey among MMT patients to collect the information about their socio-demographic characteristics, drug use, MMT, sexual behavior and health status. Software EpiData 3.1 was used for real-time double entry to establish the database. Software SAS 9.4 was used to analyze the data, and χ² test was used for univariate analysis and logistic regression model was used for multivariate and interaction analyses. Results: A total of 903 subjects were surveyed among MMT patients, the male to female ratio of was 7.21∶1(743∶103), and the rate of HCV infection was 12.53% (106/846). After adjusting for the confounding factors, being women (OR=1.936, 95%CI: 1.023-3.662), having sex with drug users (OR=2.073, 95%CI: 1.110-3.871) and injection drug use (OR=7.737, 95%CI: 4.614-12.973) might be the risk factors for HCV infection in patients receiving MMT. The results showed that there were multiplicative interactions among women, having sex with drug user and injection drug use on HCV infection. Conclusions: Being women, having sex with drug user and injection drug use were associated with higher risk for HCV infection in patients receiving MMT in Taiyuan. There were multiplication interactions between being women and having sex with drug user, being female and injection drug use, and having sex with drug use and injection drug use on HCV infection.

[Lymphocyte activation gene 3 expression on T lymphocyte cell subsets in patients with myelodysplastic syndrome]

Objective: To investigate the expression of Lymphocyte activation gene 3 (LAG3) in myelodysplastic syndromes (MDS) patients. Methods: A total of 16 MDS patients newly diagnosed in Hematology Department of Tianjin Medical University were enrolled from January to November 2019. The healthy control (HC) group includes 16 cases of healthy adults. The expression levels of LAG3 on CD8(+)T cells, CD4(+)T cells and regulatory T cells (Treg) in MDS patients and healthy controls were detected by flow cytometry. Results: A total of 16 patients with MDS were included, including 5 males and 11 females, with a median age of 56 (18-80) years old. HC group includes 16 healthy adults, 8 men and 8 women, with a median age of 40 (17-69) years. There was no statistically significant difference in gender and age composition between the two groups (both P>0.05). The expression of LAG3 on CD8(+)T cells in MDS patients (74.45%±22.31%) was significantly higher than that in HC group (58.78%±14.82%, P<0.05). The LAG3 expression on Treg in MDS patients (64.91%±10.32%) were significantly higher than that of HC group (49.09%±13.58%, P<0.05). There was no statistical difference in LAG3 expression on CD4(+)T cells between the two groups. Conclusion: The expression of LAG3 on CD8(+)T cells and Treg increases in MDS patients than that of healthy people.

[Characteristics of methadone maintenance treatment clinic patients and influencing factors for HBsAg positivity based on Bayesian network model]

Objective: To understand the characteristics and explore the influencing factors of HBsAg positivity in methadone maintenance treatment (MMT) clinic patients. Methods: A face to face interview and medical record review were conducted in 1 040 patients at three MMT clinics in Guangxi from September to November in 2014. The questionnaire information included general demographic characteristics, drug use history, MMT status, sexual behaviors, and health status, etc. Blood samples were collected from the patients at the same time for the detections of the level of HBsAg, anti-HBs and anti-HCV. By using χ(2) test, unconditional logistic regression model and Bayesian network model the influencing factors for HBsAg positivity in MMT clinic patients and the complex network relationship among these factors were explored. Results: A total of 1 031 MMT clinic patients were surveyed, the HBsAg positive rate was 11.35% (117/1 031). The anti-HCV positive rate was 71.77% (740/1 031), among the anti-HCV positive patients, the HBsAg positive rate was 10.27% (76/740). After adjusting for the confounding factors, anti-HBs positive persons might not be HBsAg positive (OR=0.05, 95%CI: 0.03-0.09), and anti-HCV positive persons might not be HBsAg positive too (OR=0.30, 95%CI: 0.17-0.52) compared with anti-HBs negative and anti-HCV negative persons, respectively. The persons with family history of hepatitis B virus infection were more likely to be HBsAg positive compared those with no such family history (OR=5.30, 95%CI: 2.68-10.52). Bayesian network model analysis results showed that family history of hepatitis B virus infection and anti-HBs were directly related with HBsAg positivity. Anti-HCV, intravenous drug use in the past three months and other drug using during treatment were indirectly related with HBsAg positivity. Conclusions: Anti-HBs, family history of hepatitis B virus infection, anti-HCV, intravenous drug use in past three months and other drug use during treatment were related with the HBsAg positivity in MMT clinic patients. So, it is necessary to enhance health education, improve health awareness and decrease high risk behaviors to reduce the rate of HBV infection.

[Effects of dynamic contrast enhancement on diffusion weighted imaging score of 3 in prostate imaging reporting and data system version 2 of peripheral zone]

Objective: To investigate the effects and value of dynamic contrast-enhanced (DCE) on diffusion-weighted imaging (DWI) score 3 in the prostate imaging data and reporting system version 2(PI-RADS V2)of peripheral zone. Methods: A retrospective study of consecutive 204 cases of prostate disease in peripheral zone was conducted from January 2015 to January 2018, including 169 cases of prostate cancer and 35 cases of non-prostate cancer. All cases were examined multi-parametric MR imaging on a 3-T MR scanner and confirmed by pathology. Images were analyzed according to PI-RADS V2.Inter-reader agreement of scores was evaluated by kappa coefficient. The constituent ratio of clinically significant prostate cancer (csPCa) in PI-RADS V2 overall scores 3, 3+1 and 4 were calculated and analyzed by non-parametric Chi-square test to determine whether the difference in composition ratio was significant. The positive rate of DCE in diffusion weighted imaging (DWI) score 3 and 4 were calculated. Results: There were 68.6%(140/204) cases in 204 patients with peripheral prostate disease who scored PI-RADS V2 overall score of 3,3+1 and 4. Kappa value was higher for the PI-RADS V2 overallscore of 4 than 3 or 3+1 in the PZ (k values of 0.802 vs 0.737 or 0.591, respectively; all P<0.01). The constituent ratio of csPCa in PI-RADS V2 overallscore of 3, 3+1 and 4 were 16.7%(3/18),43.2%(19/44),78.2%(61/78), the difference of which was significant (χ(2)=29.839, P<0.05).There was also a significant difference between the constituent ratio of csPCa in the score of 3+1 and 4 (χ(2)=15.286, P<0.01).The positive rate of DCE in cases of PI-RADS V2 overall score 3,3+1 and 4 was 76.4%(107/140).The positive rate of DCE incases of DWI score 3 and 4 were 71.0%(44/62), 80.8%(63/78),respectively. Conclusion: DCE has a certain value in PI-RADS V2 due to its high positive rate in the detection of prostate cancer in peripheral zone.DCE is helpful to DWI score 3 to improve the detection rate of csPCa.The PI-RADS V2 overall score 3+1 and 4 in the peripheral zone maybe need to be distinguished due to the different detection of csPCa.

[Relationship between SHP-1 gene methylation and STAT3 phosphorylation and prognosis in patients with myelodysplastic syndrome]

Objective: To assess the methylation level of SHP-1 promoter region and the effects on the phosphorylation of the Signal Transducers and Activators of Transcription 3 (STAT3) protein in bone marrow specimen of patients with myelodysplastic syndrome (MDS), and to explore the relationship of SHP-1 methylation and prognosis of the patients. Method: Bone marrow specimens of 93 patients with MDS were collected from the General Hospital of Tianjin Medical University from September 2010 to June 2014. The enrolled subjects included 54 males and 39 females and they were divided into the low-risk group (IPSS score:0-1.0, median: 0.5) and the high-risk group (IPSS score: 1.5-3.0, median: 2.5) according to the International Prognostic Score System (IPSS). The methylation level of SHP-1 was detected by methylation-specific polymerase chain reaction, and the level of p-STAT3 was detected using Western blot. Results: In the high-risk group, 64.44% (29/45) of the patients had methylation in the SHP-1 promoter region, which was significantly higher than the low-risk group 22.92% (11/48). Therefore, SHP-1 methylation was frequently presented in the patients of the high-risk group. Similarly, 66.67% (30/45) of the patients in the high-risk group had positive STAT3 phosphorylation status, whereas only 20.83% (10/48) were tested positive in the low-risk group. In addition, correlation analysis also revealed that the SHP-1 methylation rate was positively correlated with the positive rate of STAT3 phosphorylation (r=0.57,P<0.001). Conclusions: SHP-1 methylation is significantly correlated with the risk of MDS patients. It may be used as an independent predictor of shorter survival in patients of the high-risk group. The increased level of SHP-1 methylation will lead to the uncontrolled activation of the downstream JAK/STAT3 pathway, which in turn can cause further positive feedback to amplify the carcinogenic signal.

[Research advance in circular RNAs]

Circular RNAs (circRNAs) are a class of endogenous, covalently closed, single-stranded RNA without 3'-poly(A) and 5'-cap structures. CircRNAs are characterized by universality, diversity, stability and conservation, and have been found to regulate mammalian transcription and be translated into proteins. In this review, we summarized the biogenesis, classification, expression, distribution, biological functions and regulation of circRNAs. In addition, we discussed the association of circRNAs with diseases and the methods for identification and characterization of circRNAs. Finally, we speculated the application prospect and research direction of circRNAs.

[A preliminary study on SLAMF6 expression in patients with severe aplastic anemia]

目的

探讨SLAMF6在重型再生障碍性贫血（SAA）CD8⁺ T细胞中的表达情况及其与疾病免疫状态的相关性。

方法

选取2017年2月至2018年4月天津医科大学总医院血液科收治的初治SAA患者21例，以15例健康人外周血标本作为正常对照，应用流式细胞术（FCM）检测外周血CD8⁺ T细胞SLAMF6表达量，并与患者HGB、PLT、中性粒细胞绝对值、网织红细胞绝对值、骨髓造血功能（粒系百分比、红系百分比、淋系百分比、巨核细胞数）等临床指标及CD8⁺ T细胞功能分子穿孔素、颗粒酶B、IFN-γ表达量进行相关性分析。进一步采用anti-SLAMF6 Ab阻断其功能，FCM检测CD8⁺ T细胞穿孔素、颗粒酶B、IFN-γ分泌量。

结果

初治SAA患者CD8⁺ T细胞SLAMF6表达量明显低于正常对照，差异有统计学意义[（56.29±12.97）%对（80.96±7.36）%，t=−7.672，P<0.001]；初治SAA患者CD8⁺ T细胞SLAMF6表达量与HGB、PLT、中性粒细胞绝对值、网织红细胞绝对值、骨髓粒系百分比、骨髓红系百分比均呈正相关（P<0.05），与CD8⁺ T细胞穿孔素、颗粒酶B、IFN-γ表达量均呈负相关（P<0.05）；anti-SLAMF6 Ab阻断该信号分子后，初治SAA患者CD8⁺ T细胞anti-SLAMF6 Ab处理组穿孔素、颗粒酶B、IFN-γ表达量较未处理组明显增多，差异有统计学意义（P值均<0.05）。

结论

SLAMF6在SAA患者CD8⁺ T细胞中明显低表达，其可能作为负性免疫调节分子通过影响CD8⁺ T细胞功能分子的分泌参与SAA的发生机制。

[Characteristic and function of peripheral blood mononuclear cells-induced macrophages in patients with myelodysplastic syndrome]

目的

观察骨髓增生异常综合征（MDS）患者单个核细胞诱导的巨噬细胞的功能，分析其与MDS疾病发展的关系。

方法

以2014年9月至2015年12月天津医科大学总医院血液科24例MDS患者为病例组，以15名健康志愿者为正常对照组。收集外周血标本并分离单个核细胞，体外以GM-CSF诱导分化形成巨噬细胞。在光学显微镜下观察巨噬细胞的形态；使用流式细胞术检测巨噬细胞的数量及其表面受体CD206、SIRPα的表达水平；分别采用流式细胞术和免疫荧光显微镜检测巨噬细胞的吞噬功能。

结果

①MDS来源的巨噬细胞形态较正常对照差（形态不规则、细胞体积小、异形明显、无足突、数量减少），MDS外周血单个核细胞转化为巨噬细胞的转化率为（5.17±3.47）%，显著低于正常对照组的（66.18±13.43）%（t=3.529，P=0.001）；②MDS来源的巨噬细胞表面识别受体CD206的表达水平[（9.73±2.59）%]显著低于正常对照组[（51.15±10.82）%]（t=4.551，P<0.001），SIRPα的表达水平[（0.51±0.09）%]显著低于正常对照组[（0.77±0.06）%]（t=2.102，P=0.043）；③MDS来源的巨噬细胞吞噬免疫微球的吞噬指数、吞噬百分率分别为0.45±0.08、（23.69±3.22）%，显著低于正常对照组的0.92±0.07、（42.75±2.13）%（P值均<0.05），MDS来源的巨噬细胞吞噬单个核细胞的吞噬指数（0.24±0.04）显著低于正常对照组（0.48±0.96，t=3.464，P=0.001）。

结论

MDS患者外周血单个核细胞诱导形成巨噬细胞能力下降，吞噬识别受体减少，吞噬能力减弱。

[The clinical significance of CD(4)(+)CD(69)(+) T lymphocytes in patients with autoimmune hemolytic anemia/Evans syndrome]

Objective: To investigate the significant of peripheral CD(4)(+) CD(69)(+) T lymphocytes in patients with autoimmune hemolytic anemia (AIHA)/Evans syndrome (ES). Methods: In this study peripheral blood samples from 32 patients with AIHA/ES (15 hemolytic episode patients, 17 remission patients) and 13 healthy controls were collected. Patients with AIHA/ES were recruited in Tianjin Medical University General Hospital from October 2015 to May 2016. The percentages of CD(69)(+) T lymphocytes were analyzed by flow cytometry. The expression of CD(69) mRNA in CD(4)(+) T lymphocytes which was sorted from peripheral blood by magnetic activated cell sorting (MACS) was detected using real-time PCR. Soluable CD(69) was measured by ELISA. Results: In hemolytic episode patients, the ratio of CD(3)(+)CD(69)(+)/CD(3)(+)T lymphocytes [(3.08±1.48)%] was significantly higher than that in healthy controls [(1.28±0.83)%, P<0.01] and in remission group[(1.96±1.33)%, P<0.05]. The absolute count of CD(3)(+)CD(69)(+)T lymphocytes in hemolytic episode group [(2.94±1.81)×10(7)/L] was higher than that in healthy controls [(1.48±1.42)×10(7)/L, P<0.05]. The ratio of CD(3)(+)CD(4)(+)CD(69)(+)/CD(3)(+)CD(4)(+)T cells in hemolytic episode group [(2.16±1.56)%] was significantly higher than that in remission group [(1.16±0.62)%, P<0.05] and healthy controls[(0.94±0.78)%, P<0.05]. The quantity of CD(3)(+)CD(4)(+)CD(69)(+)T lymphocytes in hemolytic episode group[(1.04±0.98)×10(7)/L] was higher than in healthy controls [(0.44±0.38)×10(7)/L, P<0.05]. The ratio of CD(3)(+)CD(8)(+)CD(69)(+)/CD(3)(+)CD(8)(+)T lymphocyte in hemolytic episode group [(4.87±2.56)%] was significantly higher than that in healthy controls[(1.83±1.27)%, P<0.01]. The quantity of CD(3)(+)CD(8)(+)CD(69)(+)T lymphocytes in three groups did not show significant difference. The ratio of CD(3)(+)CD(4)(+)CD(69)(+)/CD(3)(+)CD(4)(+) T lymphocytes in hemolytic episode group was negatively correlated with hemoglobin (Hb) (P<0.01) , positively correlated with the percentage of reticulocytes (Ret%) (P=0.01) total bilirubin(TBil), indirect bilirubin(IBil) (P<0.01) and not correlated with absolute reticulocytes count, lactic dehydrogenase (LDH), complement 3(C3), complement 4 (C4). The ratio of CD(3)(+)CD(4)(+)CD(69)(+)/CD(3)(+)CD(4)(+)T lymphocytes in remission group was negatively correlated with Hb (P<0.05). In hemolytic episode patients CD(69) mRNA (32.26±35.11) was significantly higher than that in remission group(6.05±5.87) (P<0.05) and healthy controls (1.76±1.85)(P<0.01). CD(69) mRNA in remission group was significantly higher than healthy controls (P<0.05). Serum CD(69) in hemolytic episode patients [(494.21±16.06) ng/L] was significantly higher than that in healthy controls [(441.39±104.6) ng/L, P<0.05]. Conclusion: Our findings suggest that the proportion of CD(4)(+)CD(69)(+) T lymphocytes increase in AIHA/ES patients, which is correlated with the severity of disease.

[Relationship between anemia and clinical features and prognosis of advanced lung cancer patients]

Objective: To investigate the relationship of anemia and clinicopathological features and prognosis of patients with advanced lung cancer. Methods: The clinical data of 741 patients with stage Ⅲ~Ⅳ lung cancer were collected and analyzed retrospectively. We analyzed the incidence and type of anemia during the natural course of lung cancer patients, and its relationship with the gender, age, duration of disease, clinical stage, prognostic nutritional index (PNI) of these patients. Kaplan-Meier method and multivariate Cox regression model were used to analyze the effect of anemia on prognosis. Results: Among 741 cases of lung cancer patients, 407 (54.9%) cases were accompanied with anemia, whose hemoglobin (Hb) was (89.39±15.76) g/L, including 214 cases of mild anemia, 173 cases of moderate anemia and 20 cases of severe anemia. The most common type of anemia is anemia of chronic disease (ACD), the incidence rate of which was 79.6% (324/407), followed by the iron deficiency anemia (IDA), the incidence rate of which was 4.2% (17/407). The incidence of anemia was marginally related to the gender and age (P>0.05), but significantly related to the duration of disease, clinical stage and PNI (all P<0.05). The degree of anemia was marginally related to the gender and age (P>0.05), but significantly related to the duration of disease, clinical stage and PNI (all P<0.05). The median survival time of the patients with anemia was 10.5 months (95% CI: 10.1~10.9 ), significantly shorter than 13.0 months (95% CI: 12.2~13.8) of patients without anemia (P<0.001). The median survival time of mild anemia patients was 11.0 months (95% CI: 10.7~11.3), significantly longer than 9.6 months (95% CI: 9.1~10.1) of moderate and severe anemia patients (P=0.048). The results of Cox regression survival analysis showed that the incidence and degree of anemia were independent factors of prognosis of patients with lung cancer (P<0.05). Conclusions: During the natural course of advanced lung cancer, the incidence of anemia is high, especially ACD. The incidence and degree of anemia are substantially correlated with the duration of disease, clinical stage and PNI. The incidence and degree of anemia are independent prognostic factors of patients with lung cancer.

[Effects of different computed high b-values on diffusion weighted imaging scores in Prostate Imaging Reporting and Data System version 2 of prostate cancer in peripheral zone]

Objective: To determine the effects of different computed high b-value on diffusion weighted imaging (DWI) scores in Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) of prostate cancer in peripheral zone. Methods: A retrospective study of 104 cases of prostate cancer in peripheral zone was conducted, all of the patients were histopathologically confirmed by transrectal ultrasound guided saturation biopsy or radical prostatectomy in Tongji Hospital of Tongji University from January 2012 to December 2015.All MRI imaging examinations were performed by using a 3.0T Siemens Verio MRI scanner.The imaging protocol consisted of high-resolution axial and sagittal T(2) weighted imaging (T(2)WI), axial acquired diffusion weighted imaging (aDWI) with b=0, 50, 1 000 s/mm(2) and dynamic contrast-enhanced (DCE) scans.Computed diffusion weighted imaging (cDWI) images with b=1 000, 1 400, 2 000 s/mm(2) were processed by Matlab.These three groups of cDWI images were analyzed according to the PI-RADS v2 criteria, and signal intensity of ratio (SIR) of lesions were analyzed by independent t test and one-way ANOVA in each group. Results: The numbers of cases with a DWI score of 2 and 5 were similar among three groups.Nine cases (33.3%) in all 27 cases with a DWI score of 3 on b=1 000 s/mm(2) upgraded to score 4 when b-value rose to 1 400 and 2 000 s/mm(2).The ratios of SIR of lesions in cases upgraded from DWI score 3 to 4 to those unchanged cases on b=1 400 and 2 000 s/mm(2) were 1.86±0.21 to 1.61±0.27 and 2.18±0.26 to 1.75±0.30, respectively (t=2.486, t=3.671, both P<0.05). In these 9 cases who upgraded to DWI score 4, SIRs of the lesion were significantly different between groups when b=1 000, 1 400 and 2 000 s/mm(2) (F=10.907, 33.768, 8.043, all P<0.05), and their SIRs increased with the rising of b-value. Conclusions: The computed high b-value (b≥1 400 s/mm(2)) mainly affects cases with a DWI score of 3, but DWI scores would not change neither in b=1 400 s/mm(2) nor in 2 000 s/mm(2) cases. For DWI score in PI-RADS v2 of prostate cancer in peripheral zone, b=1 400 s/mm(2) is probably of more scoring value than b=1 000 or 2 000 s/mm(2).

[Research on the negative immune regulation of NK cells in patients with primary immune thrombocytopenia]

目的

探讨原发免疫性血小板减少症（ITP）患者外周血中NK细胞及其相关细胞因子IFN-γ、IL-10、TGF-β的变化。

方法

以22例初诊ITP患者（初诊组）、20例治疗后完全缓解ITP患者（完全缓解组）为研究对象，以20名健康志愿者为对照组。采用ELISA法检测三组受试者血清IFN-γ及IL-10水平；用流式细胞术检测NK细胞（CD3⁻CD56⁺）及其Bright亚群（CD3⁻CD56^bright CD16⁻）、Dim亚群（CD3⁻CD56^dim CD16⁺）水平；采用免疫磁珠法分离NK细胞，实时荧光定量PCR检测IFN-γ、IL-10、TGF-β基因mRNA的表达，并将以上测得结果做相关性分析。

结果

①初诊组ITP患者血清IFN-γ浓度[（653.0±221.6）ng/L]高于完全缓解组[（484.4±219.5）ng/L]和对照组[（390.9±253.5）ng/L]（P值分别为0.022、0.001），血清IL-10浓度低于对照组[（52.09±26.66）ng/L对（79.44±38.43）ng/L，P=0.007]。②初诊组、完全缓解组患者外周血NK细胞比例[（9.53±3.93）%、（9.03±3.78）%]均低于对照组[（13.72±7.42）%]（P=0.013，P=0.007）；初诊患者外周血Bright亚群占NK细胞的比例高于对照组[（6.85±4.43）%对（4.05±2.81）%，P=0.032]；初诊组外周血Dim亚群占NK细胞的比例低于对照组[（93.14±4.43）%对（95.94±2.81）%，P=0.032]。③初诊组、完全缓解组及对照组NK细胞IFN-γ基因mRNA表达差异无统计学意义（P>0.05），初诊组NK细胞IL-10、TGF-β基因mRNA表达高于对照组（1.82±1.32对1.02±1.03，P=0.023；2.80±2.31对1.46±1.37，P=0.028）。外周血Bright细胞占NK细胞的比例与NK细胞IL-10及TGF-β基因mRNA表达呈正相关（r=0.424，P=0.001；r=0.432，P<0.001）。

结论

NK细胞可能通过加强分泌免疫负调控因子来代偿其数量的不足，在疾病中起保护作用。

[Quantities and function of NK cells in patients with immune thrombocytopenia]

Objective: To investigate natural killer (NK) cell quantities and function in patients with immune thrombocytopenia (ITP) . Methods: A total of 66 ITP patients (34 newly diagnosed and 32 in complete remission) were collected from September 2015 to May 2016 in Tianjin Medical University General Hospital, and 30 healthy volunteers were recruited as controls. The percentages of NK cells and their subsets in peripheral blood, the expression of activating receptor (NKp44), inhibitory receptor (NKG2A) and CD16, perforin and granzyme β were detected by flow cytometry. The correlation between the above parameters and patients' immune status and platelet level were evaluated. Results: (1)The percentage of CD3(-)CD56(+) NK cells in newly diagnosed patients (10.99%±4.89%)and patients in complete remission (9.73%±6.75%) were significantly lower than that in healthy controls (14.67%±7.24%)(P=0.023, 0.003). The percentage of NK cells Bright subset was significantly lower in the newly diagnosed patients(0.48%±0.23%)and those in complete remission (0.41%±0.33%) than in healthy controls(0.64%±0.32%)(P=0.037, 0.002); the percentage of Dim subset was also significantly lower in the newly diagnosed (10.16%±5.02%) and patients in complete remission (8.07%±5.74%) than in healthy controls(14.16%±7.19%) (P=0.009, 0.007). (2)The proportion of Bright subset in total NK cells in new diagnosed ITP patients (6.48%±4.33%) was significantly higher than that in healthy controls (4.21%±2.70%)(P=0.020); the proportion of Dim NK cells subset in new diagnosed ITP patients (93.51%±4.33%) was significantly lower than that in healthy controls(95.79%±2.70%) (P=0.020). (3)The expression of activating receptor NKp44 in new diagnosed ITP patients was significantly lower than that in complete remission group and healthy controls[0.28%(0.95%)vs 0.61%(2.05%), 0.92%(0.90%); P=0.047, 0.048]; the expression of inhibitory receptor NKG2A in new diagnosed ITP patients was significantly higher than that in healthy controls(42.34%±23.86% vs 29.25%±12.83%, P=0.009). The proportion of CD16 was significantly lower in the newly diagnosed patients than in healthy controls(93.51%±4.33%95.79%±2.70%, P=0.020). (4)The expression of perforin in the newly diagnosed ITP patients was significantly lower than that in healthy controls [87.52%(25.29%)vs 91.55%(8.29%), P=0.025]; the expression of granzyme β in ITP patients and controls showed no statistically significant difference. (5)The level of NK cells in ITP patients was negatively correlated with CD3(+) CD8(+) T cells (r=-0.387, P=0.012) and CD5(+) CD19(+) B cells in peripheral blood (r=-0.273, P=0.028), positively correlated with the ratio of CD3(+) CD4(+) /CD3(+) CD8(+) (r=0.358, P=0.028) and peripheral platelet count (r=0.314, P=0.011). Conclusion: Deceased quantities and impaired total NK function, insufficient suppression of autoreactive T and B cells might play a role in the pathogenesis of ITP.

[Epidemiology of febrile neutropenia in patients with hematological disease-a prospective multicentre survey in China]

目的

了解中国血液病患者中性粒细胞缺乏（粒缺）伴发热的发生率、临床和微生物学特征及危险因素。

方法

前瞻性研究2014年10月20日至2015年3月20日来自全国11家血液病中心发生粒缺伴发热的连续血液病患者发热情况及危险性因素。

结果

1 139例患者共发生784例次粒缺伴发热，粒缺持续21 d时发热的累积发生率为81.9%。多因素分析显示中心静脉置管（P<0.001，HR= 3.407，95% CI 2.276~4.496）、胃肠道黏膜炎（P<0.001，HR=10.548, 95% CI 3.245~28.576）、既往90 d内暴露于广谱抗生素（P<0.001，HR=3.582，95% CI 2.387~5.770）和粒缺持续时间>7 d（P<0.001，HR= 4.194，95% CI 2.572~5.618）是粒缺伴发热的危险因素。无任何危险因素、具备1项、2项、3~4项危险因素患者发热的累计发生率依次增加（35.4%、69.2%、86.1%及95.6%，P<0.001）。784例次粒缺伴发热中，不明原因发热253例次（32.3%），临床证实的感染429例次（54.7%），微生物学证实的感染102例次（13.0%）。最常见的感染部位依次为肺（388例次，49.5%）、上呼吸道（159例次，16.0%）、肛周组织（77例次，9.8%）、血流（60例次，7.7%）。最常见的病原菌为革兰阴性菌（44.54%），其次为革兰阳性菌（37.99%）和真菌（17.47%）。发热与未发热患者相比，两组之间总体病死率差异无统计学意义（9.2%对4.8%，P=0.099）。多因素分析显示年龄>40岁（P=0.047，HR=5.000，95% CI 0.853~28.013）、血流动力学不稳（P=0.001，HR=13.185, 95% CI 2.983~54.915）、既往耐药菌的定植或感染（P=0.005，HR=28.734，95% CI 2.921~313.744）、血流感染（P=0.038，HR=9.715, 95% CI 1.110~81.969）和肺部感染（P=0.031，HR=25.905, 95% CI 1.381~507.006）是与总体死亡相关的危险因素。

结论

发热是血液病患者粒缺期常见的合并症，不同部位的感染有不同的致病菌谱。粒缺持续时间>7 d、中心静脉置管、胃肠道黏膜炎和既往90 d内暴露于广谱抗生素是粒缺伴发热发生的危险因素。

[Target cells of cytotoxic T cells in severe aplastic anemia in vitro]

OBJECTIVE

To clarify the specific target of severe aplastic anemia (SAA) immune attack via identifying the target cells of cytotoxic T cell attacks and the expression of apoptosis ligand on each department and each stage of bone marrow hematopoietic cells.

METHODS

A total of 15 SAA patients and 15 normal controls were recruited in the Department of Hematology, Tianjin Medical University General Hospital between March 2011 and March 2012. Factor associated suicide(Fas) protein expression of CD34(+) , CD14(+) , CD33(+) , and GlycoA(+) cells in bone marrow was detected by flow cytometry. The CD8(+) T cells of SAA patients and CD3(-) bone marrow mononuclear cells (BMMNC) of controls were sorted by immunomagnetic separation and co-cultured for 72 hours. The apoptosis rate of CD34(+) , CD14(+) , CD33(+) , and GlycoA(+) cells were measured with flow cytometry.

RESULTS

The expression of Fas protein in CD34(+) cells in SAA patients (46.59%± 27.60%) was significantly higher than that in control group (8.89%±7.28%, P<0.01). The expressions of Fas protein in CD14(+) , CD33(+) and GlycoA(+) cells in SAA group(29.29%±9.23%, 46.88%±14.30%, 15.15%±9.26%) were lower than those in control group(51.25%±38.36%, 72.06%±39.88%, 50.38%±39.88%, all P<0.05). The apoptosis rates of CD34(+) , CD33(+) and CD14(+) cells in the experimental group (CD8(+) T cells of SAA patients co-cultured with CD3(-) BMMNC of controls: 55.43%±20.50%, 38.13%±20.10%, 61.87%±21.65%)were significantly higher than those of the control group (CD8(+) T cells of controls co-cultured with CD3(-) BMMNC of controls: 35.02%±13.95%, 23.44%±10.33%, 37.04%±22.41%, all P<0.05).

CONCLUSIONS

Cytotoxic T cells in SAA patients may have a killing effect on hematopoietic stem/progenitor cells, and granulocytic and macrophagocytic cells from normal bone marrow. Moreover, Fas/Fas ligand-mediated apoptosis may play an important role in the immune pathogenesis of SAA. CD34(+) cells show markedly increased Fas protein expression, which may be the main target cells in the process of immune injury in SAA patients.

[Quantities and function of NK cells in patients with positive BMMNC-Coombs test and cytopenia]

OBJECTIVE

To test NK cell quantities and function in patients with positive BMMNC-Coombs test (CBCPC) and cytopenia and to explore how NK cell participate in the progress of this disease.

METHODS

The percentage of CD3(-)CD56(+) NK cell in peripheral blood lymphocytes, the expression of activating receptor (NKG2D, NKp46, NKp44), inhibitory receptor (CD158a, CD158b), perforin and granzyme-β were detected by flow cytometry. All samples were taken from 42 patients (22 newly diagnosed and 20 in remission) and 12 healthy volunteers. The correlation between the above parameters and patients' clinical profile were evaluated.

RESULTS

①The percentage of CD3(-)CD56(+) NK cell in new diagnosed and remission CBCPC patients were significantly lower than that in healthy control [(10.04 ± 5.33)% vs (19.94 ± 7.38)%; (11.62 ± 6.80)% vs (19.94 ± 7.38)%, all P<0.01]. ② The expression of activating receptor NKG2D in new diagnosed CBCPC patients was significantly higher than that in remission group and healthy control [(74.03±18.24)% vs (45.97±29.45)%; (74.03±18.24)% vs (41.89± 15.34)% , P <0.01]. ③The expression of inhibitory receptor CD158a in new diagnosed CBCPC patients was significantly lower than that in remission group and healthy control (median: 3.72% vs 16.10%, P= 0.015; 3.72% vs 11.04%, P=0.025). ④The expression of perforin in new diagnosed and remitted CBCPC patients were significantly higher than that in healthy controls [(75.71±10.14) % vs (57.20±18.85)%, P= 0.018; (77.88±22.82)% vs (57.20±18.85)%, P=0.008]. ⑤The product of NK cell percentage and perforin expression in new diagnosed and remission CBCPC patient were significantly lower than that in healthy control [(7.68±4.54)% vs (12.13±5.19)%, P=0.011; (8.24±5.80)% vs (12.13±5.19)%, P=0.023]. The product of NK cell percentage and granzyme-β expression in the new diagnosed and remission CBCPC patient were significantly lower than that in healthy control [(7.83±5.26)% vs (14.79±8.37)%, P=0.008; (8.37 ± 6.83)% vs (14.79±8.37)%, P=0.012].

CONCLUSION

Deceased quantities and impaired total NK function might play a role in pathogenesis of CBCPC.

Fas/FasL in the immune pathogenesis of severe aplastic anemia

Fas/FasL protein expression of bone marrow hematopoietic cells was investigated in severe aplastic anemia (SAA) patients. Fas expression was evaluated in CD34(+), GlycoA(+), CD33(+), and CD14(+) cells labeled with monoclonal antibodies in newly diagnosed and remission SAA patients along with normal controls. FasL expression was evaluated in CD8(+) cells in the same manner. In CD34(+) cells, Fas expression was significantly higher in the newly diagnosed SAA group (46.59 ± 27.60%) than the remission (6.12 ± 3.35%; P < 0.01) and control (8.89 ± 7.28%; P < 0.01) groups. In CD14(+), CD33(+), and GlycoA(+) cells, Fas levels were significantly lower in the newly diagnosed SAA group (29.29 ± 9.23, 46.88 ± 14.30, and 15.15 ± 9.26%, respectively) than in the remission (47.23 ± 31.56, 67.22 ± 34.68, and 43.56 ± 26.85%, respectively; P < 0.05) and normal control (51.25 ± 38.36, 72.06 ± 39.88, 50.38 ± 39.88%, respectively; P < 0.05) groups. FasL expression of CD8(+) cells was significantly higher in the newly diagnosed SAA group (89.53 ± 45.68%) than the remission (56.39 ± 27.94%; P < 0.01) and control (48.63 ± 27.38%; P <0.01) groups. No significant differences were observed between the remission and control groups. FasL expression in CD8(+) T cells was significantly higher in newly diagnosed patients, and CD34(+), CD33(+), CD14(+), and GlycoA(+) cells all showed Fas antigen expression. The Fas/FasL pathway might play an important role in excessive hematopoietic cell apoptosis in SAA bone marrow. Furthermore, CD34(+) cells are likely the main targets of SAA immune injury.

1H-MRS can monitor metabolites changes of lateral intraventricular BDNF infusion into a mouse model of Alzheimer's disease in vivo

Proton magnetic resonance spectroscopy (1H-MRS) can provide noninvasive detection of brain metabolite changes in vivo in Alzheimer's disease (AD). AD is a prevalent neurodegenerative disorder characterized by deposition of β-amyloid peptides (Aβ) in multiple brain regions. Brain-derived neurotrophic factor (BDNF) is a neurotrophic factor whose level has been shown to be decreased in AD. BDNF supplementation can offer improvement in AD. However, the means of evaluation are still relatively limited. In the present study, 1H-MRS was applied to evaluate the therapeutic effects of bilateral intraventricular BDNF infusion into APP+PS1 (amyloid precursor protein+presenilin 1) transgenic mice. For comparison to the 1H-MRS changes in the prefrontal cortex, Morris water maze (MWM) test, Fluoro-Jade B staining and immunofluorescence for Aβ, glial fibrillary acidic protein and tropomyosin-related kinase B (TrkB) were also performed. Our results showed that N-acetylaspartate (NAA) levels increased and myo-inositol levels decreased in Tg-BDNF mice compared with Tg-PBS mice. But NAA level in Tg-BDNF mice was still lower than that in wild-type mice at 6weeks after infusion. These changes correlated with increased immunoreactivity of TrkB, reduced compact Aβ peptide and FJB+ neurons in Tg-BDNF mice compared to Tg-PBS mice. However, Tg-BDNF mice did not present obvious changes in behavior in the MWM. Taken together, we suggest that 1H-MRS may be a sensitive means of evaluating metabolic changes in response to therapeutic strategies in AD. Moreover, BDNF, may be a viable means of offering trophic support during disease.

Methylation of RAR-β2, RASSF1A, and CDKN2A genes induced by nickel subsulfide and nickel-carcinogenesis in rats

OBJECTIVE

To investigate the expression variation of RAR-β2, RASSF1A, and CDKN2A gene in the process of nickel-induced carcinogenesis.

METHODS

Nickel subsulfide (Ni(3)S(2)) at dose of 10 mg was given to Wistar rats by intramuscular injection. The mRNA expression of the three genes in induced tumors and their lung metastasis were examined by Real-time PCR. The methylation status of the 5' region of these genes were detected by Quantitative Real-time methylation specific PCR.

RESULTS

The mRNA expressions of the three genes both in muscle and lung tumor were decreased distinctly in comparison with normal tissue. But hypermethylation was found only in muscle tumor.

CONCLUSION

These findings suggest that loss of function or decrease of RAR-β2, RASSF1A, and CDKN2A, as well as the hypermethylation of 5' region of these genes, are related with nickel exposure.

Cytotoxicity induced by grape seed proanthocyanidins: role of nitric oxide

Grape seed proanthocyanidin extract (GPSE) at high doses has been shown to exhibit cytotoxicity that is associated with increased apoptotic cell death. Nitric oxide (NO), being a regulator of apoptosis, can be increased in production by the administration of GSPE. In a chick cardiomyocyte study, we demonstrated that high-dose (500 microg/ml) GSPE produces a significantly high level of NO that contributes to increased apoptotic cell death detected by propidium iodide and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. It is also associated with the depletion of intracellular glutathione (GSH), probably due to increased consumption by NO with the formation of S-nitrosoglutathione. Co-treatment with L-NAME, a NO synthase inhibitor, results in reduction of NO and apoptotic cell death. The decline in reduced GSH/oxidized GSH (GSSG) ratio is also reversed. N-Acetylcysteine, a thiol compound that reacts directly with NO, can reduce the increased NO generation and reverse the decreased GSH/GSSG ratio, thereby attenuating the cytotoxicity induced by high-dose GSPE. Taken together, these results suggest that endogenous NO synthase (NOS) activation and excessive NO production play a key role in the pathogenesis of high-dose GSPE-induced cytotoxicity.

Intra- and intermolecular C-h.pi interactions in bis[benzyl 3-(fluoren-9-ylidene)dithiocarbazato-N3,S]nickel(II)

The title compound, [Ni(C(21)H(15)N(2)S(2))(2)], has a novel cis configuration with two fluorene moieties on the same side. The Ni atom is in a square-planar configuration. The molecular packing is stabilized by intramolecular stacking between the fluorene moieties and extensive C-H.pi interactions.

Preconditioning in cardiomyocytes protects by attenuating oxidant stress at reperfusion

Cardiomyocyte death after ischemia/reperfusion correlates with oxidant stress, and antioxidants confer protection in that model. Preconditioning (PC) with hypoxia or adenosine also confers protection, leading us to hypothesize that PC protects by attenuating oxidant generation during subsequent ischemia/reperfusion. Chick cardiomyocytes were preconditioned with 10 minutes of hypoxia or adenosine (100 micromol/L), followed by 1 hour of simulated ischemia and 3 hours of reperfusion. Adenosine PC decreased cell death from 50+/-3% to 18+/-4% and enhanced the return of contractions during reperfusion, as observed previously with hypoxic PC. A transient burst of dichlorofluorescein (sensitive to H2O2 oxidation that was significantly attenuated by PC initiated by hypoxia or adenosine was seen at reperfusion. The protein kinase C (PKC) inhibitor Go-6976 and the mitochondrial ATP-sensitive K(+) (K(ATP)) channel inhibitor 5-hydroxydecanoate each abolished protection and abrogated the PC-induced attenuation of reperfusion oxidant stress. By contrast, when given only at reperfusion, the K(+) channel opener pinacidil or the antioxidants 2-mercaptopropionylglycine and 1,10-phenanthroline decreased oxidant stress at reperfusion and improved survival and return of contractions. Thus, PC protection is associated with an attenuation of the oxidant burst at reperfusion, regardless of the method by which PC is triggered. Loss of PC protection associated with PKC inhibition or K(ATP) channel inhibitors is associated with a restoration of that oxidant stress. These results suggest a mechanism for PC protection and reveal a functional link between PKC activation and K(ATP) channel activation in that pathway.

Generation of superoxide in cardiomyocytes during ischemia before reperfusion

Although a burst of oxidants has been well described with reperfusion, less is known about the oxidants generated by the highly reduced redox state and low O(2) of ischemia. This study aimed to further identify the species and source of these oxidants. Cardiomyocytes were exposed to 1 h of simulated ischemia while oxidant generation was assessed by intracellular dihydroethidine (DHE) oxidation. Ischemia increased DHE oxidation significantly (0.7 +/- 0.1 to 2.3 +/- 0.3) after 1 h. Myxothiazol (mitochondrial site III inhibitor) attenuated oxidation to 1.3 +/- 0.1, as did the site I inhibitors rotenone (1.0 +/- 0.1), amytal (1.1 +/- 0.1), and the flavoprotein oxidase inhibitor diphenyleneiodonium (0.9 +/- 0.1). By contrast, the site IV inhibitor cyanide, as well as inhibitors of xanthine oxidase (allopurinol), nitric oxide synthase (nitro-L-arginine methyl ester), and NADPH oxidase (apocynin), had no effect. Finally, DHE oxidation increased with Cu- and Zn-containing superoxide dismutase (SOD) inhibition using diethyldithiocarbamate (2.7 +/- 0.1) and decreased with exogenous SOD (1.1 +/- 0.1). We conclude that significant superoxide generation occurs during ischemia before reperfusion from the ubisemiquinone site of the mitochondrial electron transport chain.

Extract from Scutellaria baicalensis Georgi attenuates oxidant stress in cardiomyocytes

Extract from Scutellaria baicalensis Georgi Attenuates Oxidant Stress in Cardiomyocytes. Journal of Molecular and Cellular Cardiology (1999) 31, 1885-1895. Scutellaria baicalensis Georgi is a Chinese herbal medicine used to treat allergic and inflammatory diseases. The medicinal effects of S. baicalensis root may result, in part, from its constituent flavones reported to have antioxidant properties. Since oxidants play multiple roles in cells, we tested whether S. baicalensis could confer protection in a cardiomyocyte model of ischemia and reperfusion. The intracellular fluorescent probes 2',7'-dichlorofluorescin diacetate (DCFH-DA, sensitive to H(2)O(2) and hydroxyl radicals) and dihydroethidium (DHE, sensitive to superoxide) were used to assess intracellular reactive oxygen species (ROS), and propidium iodide (PI) was used to assess viability in cultured embryonic cardiomyocytes. S. baicalensis extract (SbE) quickly attenuated levels of oxidants generated during transient hypoxia and during exposure to the mitochondrial site III inhibitor antimycin A, as measured by DCFH oxidation or by DHE oxidation. These attenuated oxidant levels were associated with improved survival and function. Cell death after ischemia/reperfusion decreased from 47+/-3 % in untreated to 26+/-2 % in S. baicalensis treated cells (P<0.001). After antimycin A exposure, S. baicalensis decreased cell death from 49+/-6 % in untreated to 23+/-4 % in treated cells. Return of contraction occurred in S. baicalensis-treated cells but was not observed in control cells. Other in vitro studies revealed that baicalein, a major flavone component of SbE can directly scavenge superoxide, hydrogen peroxide, and hydroxyl radicals. Collectively, these findings indicate that SbE and its constituent flavones such as baicalein can attenuate oxidant stress and protect cells from lethal oxidant damage in an ischemia-reperfusion model.

[Relationship between the familial nonrandom chromosome loss (NCL) and leukomogenesis]

By using R-banding karyotypic analysis technique, the bone marrow (BM) cells were performed in 223 hematopoietic malignacies and 105 diopathic throbocytopenic purpura (ITP), which served as control. The following results were obtained: (1) Nonrandom chromosome loss (NCL), such as, -11, -14, -21, etc, which were found in the affected members of leukemia families, were found in about 30% sporadic ANLL, MDS and about 50% ALL, espedislly in 100% (5/5) CLL, but not found in ITP (P < 0.001). These results indicated that the familial nonrandom chromosome loss were associated with leukomogenesis. (2) Because most of BM cells are hypodiploed and have the same kinds of NCL in each cases of CLL, which can develop into ALL, ANLL and also cancers, ALL BM hypo- and hyper-diploid and/or polyploid cells might be origin of hypodiploid cells. (3) 28% (6/21) of pediatric patients with AL, MDS, or FA (Fanconi Anemia) have one parent, who have up to 30% BM hypodiploid cells and similar kinds of NCL and also have the rearrangement of C-erbB and abnormal proliferation of BM. The NCL were found in the three consecutive generations of a family with 5 ALL among 10 members of third generation. It indicated that the familial NCL might be inherited and be coded by a unknown gene alteration, which might be related to leukomo and carcinogenesis, because there are genes or their candidates for leukemia in the chromosomes 11, 14 and 21. (4) Based on the works of my colleages and I, the model of leukomo and carcinogenesis was proposed and the relationship between chromosome monosomy, deletion, translocations and leukomogenesis were showed elswhere. The significance of monosomy 11, 14 and 21 etc. were discussed briefly.

[Relationship between the occurrences of AL, MDS and AA and abnormal BM proliferation of patient's parents]

After studying of familial leukemias, Myelodysplastic Syndrome (MDS) and aplastic anemia (AA), we observed and analysed bone marrow (BM) cells hematologically and molecular-cytogenetically in 36 persons who are first degree relatives (FDRs) of patients with acute leukemias (AL), MDS and AA. The peripheral blood (PB) lymphocyte chromosome fragility sensitive to folic acid and unstability was also analysed in 18 FDRs. The abnormal BM megakaryocystic/erythroid cellularity and the rearrangement of c-erbB were found in 66%-86.1% of parents and siblings of patients. The associations of dysplastic megakaryopoiesis, including the presence of lymphoid small megakaryocytes, with the chromosomal monosomy or/and the rearrangement/amplification of C-erbB, were found in a few parents and siblings. These results were consistent with those of MDS, Fanconi Anemia (FA) and AL. The normal karyotype and SCD positive of BM cells and PB lymphocytes, and PB lymphocyte chromosomal fragility and unstability were found in most of patients' parents, while familial chromosomal monosomy of BM cells and PB lymphocyte chromosomal fragility were found in parents and siblings of familial leukemia patients. Based on the studies of a large family with 7 cases of acute erythroleukamia and relative myeloleukemias in three consecutive generations and a family with 3 CAA and 1 AML, the rearrangement of c-erbB might be inherited. The rearrangement/amplification of c-erbB and its PCR detected results could be the indicators of gene diagnosis of preleukemia and might be useful in genetic conselling of leukemias. The common origin of AL, MDS and AA was discussed.

Renal responses to hypertonic saline infusion in salt-sensitive spontaneously hypertensive rats

In Wistar Kyoto (WKY) and Sprague Dawley rats, high dietary sodium chloride (NaCl) increases natriuretic and diuretic responses to acute isotonic saline infusion, but in NaCl-sensitive spontaneously hypertensive rats (SHR-S), a high-NaCl diet causes negligible increases in natriuretic and diuretic responses. To investigate whether this deficit in sodium and fluid excretion in SHR-S is stimulus (volume)-specific or because of a more generalized alteration in renal function, the present study measured, in SHR-S and Wistar Kyoto rats, natriuretic and diuretic responses to a hypertonic saline infusion (the amount of sodium infused was equal to that infused in a previous, isotonic experiment). Eight-week-old Wistar Kyoto rats, SHR-S, and salt-resistant SHR were given a basal (1%) or high (8%)-NaCl diet for 2 weeks. Intravenous infusion of hypertonic saline increased mean arterial pressure and reduced heart rate in all groups. Baseline sodium excretion was lower in SHR-S compared with salt-resistant SHR with either diet, but after infusion of hypertonic saline, all 6 groups displayed significant increases in sodium and fluid excretion, glomerular filtration rate, and effective renal blood flow (ERBF). The percent-sodium excretion in response to hypertonic saline infusion was slightly, but significantly, lower in SHR-S (compared with salt-resistant SHR) for either the basal or the high-NaCl diet. We conclude that renal responses to hypertonic saline infusion are affected minimally in SHR-S compared with salt-resistant SHR or Wistar Kyoto rats. Therefore, the deficits in renal function observed in SHR-S after volume loading are not reflected in a renal deficit to hypertonic saline challenge.

Cellular energy utilization and supply during hypoxia in embryonic cardiac myocytes

Studies of intact hearts suggest that cardiac myocytes may have the ability to reversibly suppress metabolic activity and energy demand in states of regional hypoperfusion. However, an ability to suppress respiration in response to hypoxia has never been demonstrated in isolated myocytes. To test this, isolated embryonic chick cardiac myocytes were exposed to progressive hypoxia while their rate of O2 uptake and concentrations of lactate, ATP, ADP, AMP, and phosphocreatine were measured. Compared with the value obtained at an oxygen tension (PO2) of 120 Torr, cellular O2 uptake decreased by 28 +/- 14% (SD) at PO2 = 50 Torr and by 64 +/- 25% at PO2 = 20 Torr (P < 0.05). This decrease was similar after 1 min or 2 h of hypoxia, was sustained for 16 h, and was completely reversible within 2 min after reoxygenation. The reduction in O2 uptake was associated with a decrease in the rate of ATP turnover, but no change in adenine nucleotide or phosphocreatine concentrations. In myocytes adherent to glass cover-slips, O2 uptake and contractile motion were decreased after 30-60 min at 50 and 20 Torr, compared with normoxic values. O2 uptake also was significantly decreased at 50 and 20 Torr in myocytes incubated with N,N,N',N'-tetramethyl-p-phenylenediamine, which suggests that the catalytic activity of cytochrome-c oxidase was partially inhibited during hypoxia. In summary, these results demonstrate that embryonic chick cardiac myocytes can suppress their rates of ATP demand, ATP utilization, and O2 uptake during moderate hypoxia through a mechanism that involves a reversible inhibition of cytochrome-c oxidase. This mechanism may represent a protective response to cellular hypoxia.