A novel method based on nonparametric regression with a Gaussian kernel algorithm identifies the critical components in CHO media and feed optimization.

As the composition of animal cell culture medium becomes more complex, the identification of key variables is important for simplifying and guiding the subsequent medium optimization. However, the traditional experimental design methods are impractical and limited in their ability to explore such large feature spaces. Therefore, in this work, we developed a NRGK (nonparametric regression with Gaussian kernel) method, which aimed to identify the critical components that affect product titres during the development of cell culture media. With this nonparametric model, we successfully identified the important components that were neglected by the conventional PLS (partial least squares regression) method. The superiority of the NRGK method was further verified by ANOVA (analysis of variance). Additionally, it was proven that the selection accuracy was increased with the NRGK method because of its ability to model both the nonlinear and linear relationships between the medium components and titres. The application of this NRGK method provides new perspectives for the more precise identification of the critical components that further enable the optimization of media in a shorter timeframe.

A training set selection strategy for a universal near-infrared quantitative model.

The purpose of this article is to propose an empirical solution to the problem of how many clusters of complex samples should be selected to construct the training set for a universal near infrared quantitative model based on the Naes method. The sample spectra were hierarchically classified into clusters by Ward's algorithm and Euclidean distance. If the sample spectra were classified into two clusters, the 1/50 of the largest Heterogeneity value in the cluster with larger variation was set as the threshold to determine the total number of clusters. One sample was then randomly selected from each cluster to construct the training set, and the number of samples in training set equaled the number of clusters. In this study, 98 batches of rifampicin capsules with API contents ranging from 50.1% to 99.4% were studied with this strategy. The root mean square errors of cross validation and prediction were 2.54% and 2.31% for the model for rifampicin capsules, respectively. Then, we evaluated this model in terms of outlier diagnostics, accuracy, precision, and robustness. We also used the strategy of training set sample selection to revalidate the models for cefradine capsules, roxithromycin tablets, and erythromycin ethylsuccinate tablets, and the results were satisfactory. In conclusion, all results showed that this training set sample selection strategy assisted in the quick and accurate construction of quantitative models using near-infrared spectroscopy.

[Clinical and laboratory investigation of patients with hematologic malignancies harboring der(1;7)(q10;p10)].

OBJECTIVE: To investigate the clinical and laboratory characteristics of patients with various hematological malignancies harboring der(1;7)(q10;p10). METHODS: Bone marrow samples were collected and undergone short-time unstimulated culture and R-banding, and karyotyped by conventional cytogenetic assay (CCA). Megalokaryocytes were detected by streptavidin-AKP (SAP). Retrospective analyses including the clinical and laboratory data were performed. RESULTS: Nineteen of the 21 patients were male. Most of the patients are of older age. Thirteen cases (61.9%) were der(1;7)(q10;p10) without additional aberrations, 8(38.1%) patients had additional aberrations. Sixteen out of the 18 cases (88.9%) who underwent SAP analysis had diminutive megalokaryocyte, and lymphoid megalokaryocyte was found in 10 cases (55.6%). The der(1;7) patients manifested poor response to treatment. CONCLUSION: The der(1;7) patients demonstrated distinct male predominance, older age at diagnosis, and some clinically distinctive features. These patients showed poor prognosis. The cytogenetic abnormality, i.e., der(1;7)(q10;p10), can be used as a prognostic indicator.

[Clinical and cytogenetic features and their influencing factors of core binding factor acute myeloid leukemia].

OBJECTIVE: To discuss the clinical and cytogenetic features of core binding factor (CBF) acute myeloid leukemia (AML) patients and the main factors that influence the prognosis. METHOD: Totally 130 CBF AML patients were followed up and their clinical features, immunophenotype, chromosome karyotype, treatment regimen, overall survival (OS), and relapse-free survival (RFS) were analyzed. RESULTS: The overall complete remission (CR) rate was 96.1%, among which the CR rate after the first treatment course was 77.2%. The overall median OS was 51.64 (0.26-132.5) months, while the median RFS did not reach 1.18-96.62 months. The 3-year OS was 50% and the 5-year OS was 41%; the 3-year RFS was 59% and the 5-year RFS was 54%. Patients who were over 45 years and those with chromosome karyotype of 9q- tended to have poorer prognosis. During the consolidating chemotherapy, patients who had received two or more courses of intermediate-dose Ara-C therapy had better prognosis and longer survival. AML patients with inv (16) /t (16; 16) had a significantly higher OS than those with t (8; 21) (P = 0.046), while the RFS showed an opposite finding (P = 0.038). CONCLUSIONS: Age, chromosomal karyotype, and consolidating chemotherapy are the main factors that influence the survival and prognosis of CBF AML patients. Two or more courses of intermediate-dose Ara-C during consolidating chemotherapy can obviously prolong the OS and RFS of CBF AML patients. AML patients with a chromosomal karyotype of inv (16) /t (16; 16) have longer OS and better prognosis than those with t (8; 21).

[A new prognostic stratification for patients with acute myeloid leukemia].

OBJECTIVE: To evaluate the impact of the percentage of residual blasts in bone marrow at the end of induction chemotherapy (T1) or during myelosuppression phase (T2) on prognosis of de novo acute myeloid leukemia (AML) (non M(3)) in 105 cases. To refine AML risk-stratification by combining the percentage of residual blast cells (T1 or/and T2) with cytogenetic data based the South West Oncology Group (SWOG) criteria. METHODS: The data of 105 de novo AML (non M(3)) patients hospitalized between January 1st 1999 and February 1st 2008 were retrospectively reviewed. Results were analyzed with SPSS15.0 software. RESULTS: (1) Patients were divided into two subgroups by a cutoff of 5% residual bone marrow blasts at T1 or T2 time point. Patients with percentage of residual bone marrow blast cells < 5% had better complete remission (CR) rate, relapse-free survival (RFS) and overall survival (OS) than the patients with percentage > or = 5% at T1 or T2. The percentage of residual bone marrow blast cells at T1 was correlated with that at T2. (2) The prognosis of patients with intermediate karyotypes with percentage < 5% at T1 or T2 was similar to that of the patients with favorable karyotypes. The patients with intermediate karyotypes and percentage of residual bone marrow blasts > or = 5% at T1 or T2 are defined as a subgroup with prognosis similar to that of patients with unfavorable karyotypes. (3) COX regression analysis showed that the percentage of residual bone marrow blasts at T1 or T2 is an independent prognostic factor of AML. The percentage of residual bone marrow blasts at T1 may be more helpful in prognostication than that at T2. CONCLUSION: AML patients with percentage of residual bone marrow blasts < 5% after induction chemotherapy (T1 or T2) have better CR rate, RFS, OS than the patients with percentage > or = 5% at the same time point. Combination of cytogenetics and percentage of residual bone marrow blasts at T1 or T2 is helpful to divide patients with intermediate karyotypes into two subgroups with different prognosis. Thus, a better decision of treatment strategy can be designed.

[Chromosome 13q deletion detected by interphase FISH in multiple myeloma: a study of 100 cases in China].

OBJECTIVE: To summarize the clinical significance and 13q- characters of 100 multiple myeloma (MM) patients detected by interphase fluorescence in situ hybridization (i-FISH). METHODS: Specimens of bone marrow were collected from 100 patients with MM who visited the Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences in Tianjin, China. Chromosome R-banding analysis and i-FISH were conducted. RESULTS: (1) i-FISH was used to investigate 100 patients with MM, whose median age was 56 years and 19 (19.0%) cases showed chromosome 13q deletions/monosony13 (Delta13); conventional cytogenetics (CC) revealed informative MM karyotypes in 24 patients (24.0%),with Delta13 in 10 (10.0%) of them. Detection rate of the two methods had no significant difference (P = 0.053), but in newly diagnosed patients i-FISH was much more sensitive than CC test (Detection rate, 25.3% vs 9.3%, P = 0.008). (2) Among the whole cases, 93 of them had complete follow-up information. The overall survival (OS) of the 93 patients was 41 (1-69) months. Univariate analysis showed that the positive rate of Delta13 detected by i-FISH >50%, clonal chromosome 13 abnormality (C13A), nonhyperdiploidy, Delta13 detected by both CC and i-FISH, beta2-MG > or = 3.5 mg/L were associated with significantly shorter OS. Multivariate analysis indicated that the positive rate of Delta13 detected by i-FISH > 50% and beta2-MG > or = 3.5 mg/L were the independent unfavorable factors. (3) According to the two independent unfavorable factors mentioned above, we divided the 93 patients into three groups: low-risk, standard-risk and high-risk. And there were significant differences of OS among the 3 groups (P < 0.05). CONCLUSION: (1) FISH studies demonstrate a high sensitivity at detecting chromosome 13 abnormality and should be used in the routine evaluation of MM. (2) The positive rate of Delta13 detected by i-FISH > 50% and beta2-MG > or = 3.5 mg/L were the independent adverse prognostic factors.

Enhancing Immune Response and Heterosubtypic Protection Ability of Inactivated H7N9 Vaccine by Using STING Agonist as a Mucosal Adjuvant.

Influenza vaccines for H7N9 subtype have shown low immunogenicity in human clinical trials. Using novel adjuvants might represent the optimal available option in vaccine development. In this study, we demonstrated that the using of the STING agonist cGAMP as a mucosal adjuvant is effective in enhancing humoral, cellular and mucosal immune responses of whole virus, inactivated H7N9 vaccine in mice. A single dose of immunization was able to completely protect mice against a high lethal doses of homologous virus challenge with an significant dose-sparing effect. We also found that intranasal co-administration of H7N9 vaccine with cGAMP could provide effective cross protection against H1N1, H3N2, and H9N2 influenza virus. Furthermore, cGAMP induced significantly higher nucleoprotein specific CD4+ and CD8+ T cells responses in immunized mice, as well as upregulated the IFN-γ and Granzyme B expression in the lung tissue of mice in the early stages post a heterosubtypic virus challenge. These results indicated that STING agonist cGAMP was expected to be an effective mucosal immune adjuvant for pre-pandemic vaccines such as H7N9 vaccines, and the cGAMP combined nasal inactivated influenza vaccine will also be a promising strategy for development of broad-spectrum influenza vaccines.

Influence of cytological stains on comparative genomic hybridization analysis for DNA extracted from cytological smears.

In the present study, we investigated the influence of cytological stains in analyzing DNA extracted from cytological slides by comparative genomic hybridization (CGH). Multiple imprint cytological slides were prepared for fresh-frozen breast cancer tissue samples and the slides were stained by three staining methods for each sample. Under microscopic observation, cancer cells were selectively microdissected from the slides and forwarded to DNA extraction, whole genome amplification, and CGH analysis. CGH was successfully performed for all methylgreen-stained and May-Grunwald-Giemsa (MGG)-stained cytological smear slides, but for two Papanicolaou (PAP)-stained slides. The number of chromosomal imbalances detected were 5-10 in methylgreen-stained slides and 5-9 in MGG-stained slides. The chromosomal imbalances resemble each other between methylgreen-stained and MGG-stained slides. The present study indicates that the MGG stain is preferred to the PAP stain for the purpose of cytogenetical analysis by CGH for DNA extracted from cytological smear slides.

[Clinical and laboratory investigation of hematological malignancy patients carrying 3q21q26 rearrangement].

OBJECTIVE: To investigate the clinical and laboratory characteristics of various hematopoietic malignant patients with t(3;3)(q21;q26) or inv(3) (q21q26). METHODS: Bone marrow samples were collected at presentation, prepared by short-time unstimulated culture and R-binding, and karyotyped by conventional cytogenetical assay (CCA); megalokaryocytes were detected by Streptavidin-AKP (SAP); immunotype of the leukemia cells was tested by flow cytometric anylysis of surface antigens (FACS). RESULTS: All of the 9 hematopoietic malignant patients with t(3;3)(q21;q26) or inv(3) (q21q26) manifested myelodysplasia and poor treatment response. One of them relapsed shortly after allogenic hemotopoietic stem cell transplantation (allo-HSCT). CONCLUSION: Patients with 3q21q26 rearrangement can be found in various hematopoietic malignances and demonstrate an unique entity. These patients show poor treatment response and have extremely poor prognosis.

[Chromosomal structural changes in patients with myelodysplastic syndrome].

OBJECTIVE: To study the clinical and laboratory features of myelodysplastic syndromes (MDS) with chromosomal structural changes. METHODS: Among 584 MDS cases with cytogenetic data, 50 patients with chromosomal structural changes, 34 males and 16 females, aged 50.5 (9 approximately 77), were reclassified according to the WHO criteria, and their clinical and laboratory features were analyzed retrospectively. RESULTS: The incidence of chromosomal structural changes in the MDS patients was 7.4%. i (17) (q10), t (1; 3) (p36; q21), der (1; 7) (q10; p10), and der (22) occurred frequently. The chromosomal structural changes in 13 cases were reported in the literatures for the first time. The patients with i (17) (q10) were characterized by moderate to severe anemia and a poor prognosis. Predominant dysgranulocytopoiesis and dysmegakaryocytopoiesis, including a nuclear shift to the left, pseudo-Pelger-Hüet anomaly, hypogranularity, and increased micromegakaryocytes. The patients with t (1; 3) (p36; q21) revealed macrocytic anemia, obvious dysmegakaryocytopoiesis, and dysgranulocytopoiesis, accompanied by defective differentiation and monocytosis. The bone marrow cells from the MDS patients with t (1; 3) (p36; q21) mainly or only expressed MEL1. The initial symptom of the patients with der (1; 7) (q10; p10) was infection. These patients showed macrocytic or normocytic anemia. Trilineage dysplasia was found in the bone marrow smears. The patients had short median survival. The patients with der (22) revealed anemia, and normal or elevated platelet counts. Hypogranularity and pseudo-Pelger-Hüet anomaly were present in all cases with der (22). The megakaryocytes were small and generally contained one or two nuclei. A translocation involvement of 22q11 was frequently found in the patients with der (22). CONCLUSION: MDS patients with i (17) (q10), t (1; 3) (p36; q21), and der (1; 7) (q10; p10) may be a new unique clinical-pathologic subsets. Whether the MDS patients with der (22) can be considered as a new unique subject remains to be confirmed by future studies.

[Cytogenetic characteristics of patients with multiple myeloma in China: analysis of 100 case].

OBJECTIVE: To summarize the cytogenetic characteristics of patients with multiple myeloma (MM) in China and clinical significance thereof. METHODS: Specimens of bone marrow were collected from 100 patients with MM who visited the Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences in Tianjin, China. Chromosome banding analysis and fluorescence in situ hybridization (FISH) were conducted. RESULTS: (1) Clonal chromosome aberrations (CA) were detected in 16 of 93 patients (17.2%) by conventional cytogenetics (CC), and when subclonal CA was included CA were detected in 37.0% of the patients. Numerical aberration analysis showed that the most common trisomies were 11, 21, 3, 6, and 12, and the most common monosomies were 16, 13, 8, 22, and 11. Structural aberration analysis showed that the most frequently involved arms were 14q, 8q, 1q, 6q, 11q, 12p, and 1p, and the most frequently involved breakpoints were 14q32, 8q22 - 24, 11q13 - 14, 6p21, 1q10 - 11, and 12p12 - 13. Ploidy level was arranged in decreasing order as: hypodiploidy (46.1%), pseudodiploid (38.5%), hyperdiploidy (18.8%), and tri-/tetraploidy (15.4%). Chromosome 13 abnormality (C13A) was detected in 7 of the 100 patients (7%). The C13A prevalence rates by CC and interphase FISH were 6.0% and 33.3% respectively. Translocations involving chromosome 14 and/or 14q32 aberrations were detected in 6 patients (6.0%). (2) Univariate analysis showed that C13A, nonhyperdiploidy, and clonal CA were associated with significantly shorter overall survival (OS) and time to progression (TTP). Multivariate analysis showed that C13A was the only independent unfavorable factor. CONCLUSION: The concrete CA of the patients with MM in China are comparable to those from Western countries, among which C13A, nonhyperdiploidy, hyperdiploidy, and translocations involving immunoglobulin heavy chain locus (IgH) are recurrent. C13A, nonhyperdiploidy, and clonal CA are associated with shorter OS and time-to-progression, and C13A is the only independent adverse prognostic factor.

[An analysis of cytogenetic characteristics and prognosis of 189 t (8; 21) acute myeloid leukemia patients].

OBJECTIVE: To investigate the cytogenetic and prognostic significance of acute myeloid leukemia (AML) with t (8; 21). METHODS: 189 patients with t (8; 21) AML were categorized according to their additional karyotypic aberration and their clinical outcomes analysed. RESULTS: Among them, 63 patients (33.3%) were t (8; 21) without other additional aberrations, 126 cases (66.7%) were t (8; 21) with other additional aberrations. -Y was found in 46.7% (63/135) of the male and -X was found in 25.9% (14/54) of female patients. In additional aberrations, loss of the sex chromosome were found in 77 cases (61.1%), Del (9q) was found in 16 cases (12.7%), +4 was found in 5 cases (4.0%); 7q- was found in 6 cases (4.8%); Tetraploidy (4N) was found in 2 cases (1.6%); Variant translocation was found in 7 cases (5.6%). The 189 patients had a high remission rate (87.0%) and a relatively long median survival (21.6 months). +4 and 4N were an unfavorable prognostic factors. Fluorescence in situ hybridization technique is a more sensitive and accurate method to detect t (8; 21), especially in variant translocation, complex variant translocation and masked translocation. CONCLUSION: t (8; 21) AML is also frequently associated with additional chromosome aberrations, these aberration had influence on prognosis.

Overcoming nutrient limitations for cell-based production of influenza vaccine.

Metabolic analysis for medium optimization represents a very useful strategy in the process development of production of vaccines in cells. During influenza vaccine production, viruses hijack host cells and take advantage of host's metabolism. As a consequence, the nutritional demand of host cells should undergo a profound change, and usually more nutrients such as glucose and amino acids should be consumed. As such, the maintaining media used in virus production processes often cannot provide sufficient nutrients, and novel methods are urged to be established to address this severe issue of nutritional limitation. A detailed study on impacts of influenza virus on cell death and metabolism, with a profound analysis of nutritional requirements during virus production process, followed by a rational medium optimization is expected to be the most straightfoward and effective strategy. This would ensure a balanced and adequate nutritional supply, which should minimize cell death and improve both cell-specific virus yield and total influenza virus production. Such a metabolic analysis-based medium optimization would lay a solid foundation for the development of cell culture technology in influenza vaccine production.

Serum-Free Suspension Culture of MDCK Cells for Production of Influenza H1N1 Vaccines.

Development of serum-free suspension cell culture processes is very important for influenza vaccine production. Previously, we developed a MDCK suspension cell line in a serum-free medium. In the present study, the growth kinetics of suspension MDCK cells and influenza virus production in the serum-free medium were investigated, in comparison with those of adherent MDCK cells in both serum-containing and serum-free medium. It was found that the serum-free medium supported the stable subculture and growth of both adherent and suspension cells. In batch culture, for both cell lines, the growth kinetics in the serum-free medium was comparable with those in the serum-containing medium and a commercialized serum-free medium. In the serum-free medium, peak viable cell density (VCD), haemagglutinin (HA) and median tissue culture infective dose (TCID50) titers of the two cell lines reached 4.51×106 cells/mL, 2.94Log10(HAU/50 µL) and 8.49Log10(virions/mL), and 5.97×106 cells/mL, 3.88Log10(HAU/50 µL), and 10.34Log10(virions/mL), respectively. While virus yield of adherent cells in the serum-free medium was similar to that in the serum-containing medium, suspension culture in the serum-free medium showed a higher virus yield than adherent cells in the serum-containing medium and suspension cells in the commercialized serum-free medium. However, the percentage of infectious viruses was lower for suspension culture in the serum-free medium. These results demonstrate the great potential of this suspension MDCK cell line in serum-free medium for influenza vaccine production and further improvements are warranted.

[Clinical and cytogenetic features of 29 cases of myelodysplastic syndrome associated with del(20q)].

OBJECTIVE: To analyze the clinical and cytogenetic features of myelodysplastic syndrome(MDS) associated with del(20q). METHODS: The cytogenetic profiles, clinical manifestations, laboratory data, and transformation in course of disease were analyzed. RESULTS: (1) Of 29 MDS patients with del(20q), eleven (37.9%) had normal karyotype in addition to del(20q) aberration. Among them, nine patients were categorized into refractory anemia(RA)/RA with ringed sideroblasts(RAS) group and two into RA with excess Hasts(RAEB)/RAEB in transformation(RAEB-T) group. The breakpoint in 20q11 was commonly seen in patients with RA/RAS(63.2%), while del(20q12) was predominant in patients with RAEB/RAEB-T(accounting for 70% in all RAEB/RAEB-T patients). It was observed that RAEB/RAEB-T patients had higher frequencies of extra chromosomal aberrations(50%) and complex karyotype(30%) than did the RA/RAS patients (26.3%, 5.3% respectively); (2) Almost all patients revealed prominent pancytopenia, dyserythropoiesis and dysgranulopoiesis and 58.6% patients showed dysmegakaryopoiesis; positive periodic acid schiff staining of nucleated erythrocytes or reduction of neutrophils were found in 62.5% of patients; 81.8% of patients expressed lymphoid antigens; (3) Two cases transformed to acute myeloid leukemia. CONCLUSION: Del(20q) may be an early and primary cytogenetic event in the development of hematologic malignancies. Pancytopenia and dysplasia of bone marrow cells are prominent in patients with MDS associated with del(20q); lymphoid antigen expression is a common occurrence; more additional chromosomal abnormalities and complex karyotypes appear when the disease becomes worse.

[Molecular cytogenetic analysis of -7/7q- abnormalities in patients with myeloid malignancies].

OBJECTIVE: To accurately evaluate the incidence of -7/7q- abnormality in acute myeloblastic leukemia (AML) and myelodysplastic syndrome (MDS) patients and investigate the value of fluorescence in situ hybridization (FISH) technique in the detection and identification of -7 and 7q abnormality. METHODS: A FISH assay was performed to analyze 70 AML/MDS patients who had received conventional cytogenetic analysis (CCA). The dual color probes CEP 7 labeled by SpectrumGreen and D7S486 (locus at 7q31) labeled by SpectrumOrange were used. RESULTS: The incidence of -7/7q- in AML and MDS patients was 4.51% (31 out of 687 cases) and 5.71% (28 out of 490 cases), respectively, and was 5.68% and 10.29% in these patients with abnormal karyotype, respectively. The common deletion region of 7q- was 7q21a222 (ten cases) and 7q31-35(ten cases). FISH assay confirmed the -7/7q- aberration in those with clonal -7/7q- abnormalities, but failed in those with random -7/7q- and normal karyotype. In 7q- group, FISH revealed seven of eleven cases with monosomy 7 clone detected in the same specimen, but the numbers of 7q- interphases cells were much greater than those of monosomy 7 cells (average 42.5% vs 8.4%, P=0.025). FISH also provided precise refinement for three chromosomal structural abnormalities associated with 7q seen in CAA, one case with del(7)(q22) being refined as chromosomal translocation, one case with 7q+ being confirmed as dup(7q), and one case with complex translocation involving 7q being also proved to be true. CONCLUSION: FISH is a powerful tool to identify or refine chromosomal structural aberrations involving 7q, and it provides accurate evaluation of -7/7q- in all the patients. -7 and 7q- clone frequently coexist in the same specimen, and the significantly increasing percentage of 7q- cells implies that -7 clone secondary to 7q- clone is a result from loss of 7q-.

ERIC-PCR genotyping of Pseudomonas aeruginosa isolates from haemorrhagic pneumonia cases in mink.

BACKGROUND: Pseudomonas aeruginosa is a significant pathogen of mink and the cause of haemorrhagic pneumonia, an acute fatal disease in farmed mink. RESULTS: Among 90 P. aeruginosa isolates from haemorrhagic pneumonia in mink from 16 farms in Shandong province, China, 43 genotypes were identified by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR), with a diversity index of 0.96. The most prevalent ERIC-PCR types were type 18, found in 16 isolates, and type 39, found in 15 isolates. Four serotypes were detected, with serotype G (55.6 per cent) being the most frequent. CONCLUSIONS: These results showed that there was a high degree of clonal diversity among mink P. aeruginosa clinical isolates in this study.

Rational design of medium supplementation strategy for improved influenza viruses production based on analyzing nutritional requirements of MDCK Cells.

Influenza vaccine production using cell culture technology has become popular nowadays. However, to meet the ever increasing demand of influenza vaccine, it is prerequisite to improve the yield of influenza virus in cells. To achieve this, in the present study, the nutritional requirements of MDCK cells in the virus production process were analyzed and a nutrient-feeding strategy was developed accordingly. Based on the consumption rates and corresponding concentration optimization, glucose and fast metabolized amino acids were supplemented into the maintaining medium at the time of infection. Compared with the non-supplemented culture, the average cell specific death rate during 0-48 h post-infection was 0.013 h(-1), which was 40.91% lower in the nutrient-supplemented culture. Total virus titer, HA antigen protein concentration and cell-specific virus yield were (1.88±0.23)×10(3) HA units/50µL, 11.70±0.22 µg/mL and (10.06±1.16)×10(3) virions/cell, respectively, which were 84.04±22.50%, 31.46±2.87% and 86.64±25.81% higher than those in the control, respectively. These data showed that the appropriate supplementation of nutrients during virus production process could reduce cell death, and improve cell-specific virus yield and total influenza virus output. This study laid foundation for the development of cell culture technology for influenza vaccine production.

An investigation into the relationship between metabolic responses and energy regulation in antibody-producing cell.

Energy-efficient metabolic responses were often noted in high-productive cultures. To better understand these metabolic responses, an investigation into the relationship between metabolic responses and energy regulation was conducted via a comparative analysis among cultures with different energy source supplies. Both glycolysis and glutaminolysis were studied through the kinetic analyses of major extracellular metabolites concerning the fast and slow cell growth stages, respectively, as well as the time-course profiles of intracellular metabolites. In three cultures showing distinct antibody productivities, the amino acid metabolism and energy state were further examined. Both the transition of lactate from production to consumption and steady intracellular pools of pyruvate and lactate were observed to be correlated with efficient energy regulation. In addition, an efficient utilization of amino acids as the replenishment for the TCA cycle was also found in the cultures with upregulated energy metabolism. It was further revealed that the inefficient energy regulation would cause low cell productivity based on the comparative analysis of cell growth and productivity in cultures having distinct energy regulation.

[Acute myeloid leukemia with t(11;12)(p15;q13) translocation: two cases report and literature review].

OBJECTIVE: To investigate the clinical and laboratory features of acute myeloid leukemia (AML) with t(11;12)(p15;q13) translocation. METHODS: Two cases of AML with t(11;12)(p15;q13) translocation were reported and the related literatures were reviewed. RESULTS: The diagnosis of AML-M3 was supported by morphological, cytochemical staining and electron microscope tests. A rare t(11;12)(p15;q13) translocation, but not classical t(15;17)(q22;q12) translocation and PML- RARα fusion gene, was detected in both cases. Both of the patients were refractory to differentiation induction therapy such as retinoic acid and arsenic trioxide. CONCLUSION: AML is a group of heterogeneous disease derived from hematopoietic stem cell. Cytogenetic characteristic is important for diagnosis, prognosis stratification and therapy selection. Because of the heterogeneity of clinical and molecular features, it is unsuitable to classify AML with t(11;12)(p15;q13) as AML with recurrent cytogenetic aberration. This group of disease may benefit from allogeneic hematopoietic stem cell transplantation.