Analytical method for calculating internal stray radiation from an IR spectrometer based on the view factor.

Optomechanical components such as the lens barrels and frames of IR spectrometers produce strong internal stray radiation, which reduces the instrument's SNR and dynamic range. An IR internal stray radiation calculation method based on an analytical model of the view factor is proposed. The mathematical model of the view factor calculation method of typical optomechanical components is established. For any IR optical systems, the internal stray radiation can be quickly and accurately calculated by adjusting the coordinate systems in the calculation method. Based on the proposed method, the internal stray radiation of a double-pass long-wave IR spectrometer was calculated. The calculation results are consistent with the simulation results. The RMS value of the relative error between the calculated value and the simulated value is around 11%. To verify the proposed method, an experiment was conducted to test the internal stray radiation of the long-wave IR spectrometer. The internal stray radiation test results agree with the calculated and simulated results, and the relative error between the test results and the calculation results is within 9%.

[Assemblage composition and distribution of meiofauna in the southern Yellow Sea cold water mass during summer and autumn].

In order to study the impact of the Yellow Sea cold water mass (YSCWM) on meiofauna, the composition, abundance, biomass of meiofauna and their relationships with environmental variables were analyzed through the samples from 8 stations investigated by R/V 'Dongfanghong II' in June and November, 2013. The results showed that the average abundances of meiofauna were 900.8 and 758.4 ind · 10 cm(-2), and biomasses were 886.9 and 615.7 µg · 10 cm(-2) in June and November, 2013, respectively. Results of ANOVA showed that no significant differences of meiofaunal abundance and biomass were detected among the 8 stations in the two study cruises. A total of 17 meiofaunal groups were identified. The most dominant taxonomic group was free-living marine nematodes, with relative dominance of 88.5% in June and 94.0% in November. The following groups were also important, including benthic copepods, polychaetes, kinorhynchs and ostracods. Analysis of meiofaunal vertical distribution indicated that 92.5% and 95.4% of meiofauna distributed in the top 5 cm of the sediment in the two study cruises, while 59.1% of nematodes and 78.2% of copepods were found in the top 2 cm of the sediment. Correlation analysis among meiofaunal abundance and biomass, nematode and copepod abundance and environmental variables showed that meiofaunal abundance and biomass had significant negative correlations with bottom water temperature (BWT) and sediment silt-clay percentage. Copepod abundance also had significant negative correlations with BWT and silt-clay percentage while it had significant positive correlation with sediment median diameter. The results of BIOENV indicated that BWT, bottom water salinity, sediment water content, sediment chlorophyll a and phaeophorbide contents were the most important factors to influence meiofaunal assemblages.

[Effects of sewage discharge on abundance and biomass of meiofauna].

In order to elucidate the effects of sewage discharge on abundance and biomass of meio- fauna, a seasonal survey was carried out on meiofauna at stations with different distances to a sewage outlet in the middle intertidal zone of No. 1 bathing beach in Huiquan Bay, Qingdao in spring (April), summer (August), autumn (October) and winter (December), 2011. The results showed that the annual average meiofaunal abundance was (1859.9 ± 705.1) ind · 10 cm(-2), with higher values of (2444.9 ± 1220.5) ind · 10 cm(-2) at Station S2 (20 m to the sewage outlet) and (2492.2 ± 1839.9) ind · 10 cm(-2) at Station S3 (40 m to the sewage outlet), while the lowest value of (327.9 ± 183.2) ind · 10 cm(-2) was observed at Station S1 (0 m to the sewage outlet) in terms of horizontal distribution. The annual average biomass was (1513.4 ± 372.7) µg · 10 cm(-2). Meiofaunal abundance and biomass varied seasonally with the highest values in spring and the lowest values in summer. A total of 11 meiofaunal groups were identified, including nematodes, copepods, polychaetes, oligochaetes, tardigrades, halacaroideans, planarians, ostracods, isopods, crustacean nauplii and others. Free-living marine nematodes were the dominant group constituting 83. 1% of the total abundance, followed by benthic copepods, accounting for 12. 8% of the total abundance. In terms of vertical distribution, most of the meiofauna concentrated in the top 0-2 cm, and the meiofauna abundance decreased with increasing the sediment depth. Meiofauna was also noted to migrate deeper into the sediment in the winter. Pearson correlation analysis showed that meiofaunal abundance and biomass had highly significant negative correlations with sediment median particle diameter and organic matter content. In addition, tourism-induced activities affected meiofaunal abundance and distribution. A comparison with historical data from similar studies was carried out, and the applicability of the ratio of abundance of nematodes to copepods in monitoring organic pollution was discussed.

[Distribution and seasonal dynamics of meiofauna in intertidal zone of Qingdao sandy beaches, Shandong Province of East China].

An investigation was conducted on the abundance, group composition, and distribution of meiofauna at the Second Beach of Taiping Bay and the Shilaoren Beach in Qingdao in January, April, July, and October 2008, aimed to analyze the distribution and seasonal dynamics of meiofauna in the intertidal zone of Qingdao sandy beaches. The measurements of environmental factors, including sediment grain size, interstitial water salinity, interstitial water temperature, organic matter content (TOC), and chlorophyll a (Chl a) content, were made simultaneously. There existed obvious seasonal differences in the environment factors, which could be clustered into two groups, i. e. , spring-winter group (January and April) and summer-autumn group (July and October). At the Second Beach of Taiping Bay, the mean annual abundance of meiofauna was (1167.3 +/- 768.3) ind x 10 cm(-2), and the most dominant group was Nematoda, accounting for 91% of the total. The meiofaunal group composition and abundance at the Second Beach differed horizontally, with the abundance ranked as high tide zone < middle tide zone < low tide zone. The meiofaunal group composition and abundance also varied seasonally, with high values in spring/winter and low values in summer/autumn (spring > winter > autumn > summer). The vertical distribution of the meiofauna in the high and middle tide zones of the Second Beach varied seasonally too. The meiofauna migrated downward with increasing temperature, concentrated in surface layer in winter and migrated downward in summer. At the Shilaoren Beach, the mean annual abundance of meiofauna was (1130.2 +/- 1419.1) ind x 10 cm(-2), and Nematoda accounted for 85% of the total. There was a great similarity of the environmental factors in the middle tide zone of the Second Beach and Shilaoren Beach, which led to no differences in the meiofaunal group composition and abundance. However, the vertical distribution of the meiofauna differed between the two beaches. When the temperature decreased, the meiofauna at Shilaoren Beach migrated downward. The ANOVA and BIOENV analyses showed that the TOC and MD phi were most responsible for the distribution of meiofauna among the tidal zones, the interstitial water temperature, MD phi, and TOC were the main causes of the seasonal variation of meiofaunal group composition and abundance, whereas the sediment Chl a affected the vertical migration of meiofauna. Tourism-induced sediment variation was another factor affecting the meiofaunal abundance, group composition, and distribution.

Gilvimarinus chinensis gen. nov., sp. nov., an agar-digesting marine bacterium within the class Gammaproteobacteria isolated from coastal seawater in Qingdao, China.

A taxonomic study was performed on strain QM42(T), which was isolated from coastal seawater from an aquaculture site near Qingdao, China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain QM42(T) was a member of the class Gammaproteobacteria. Cells of strain QM42(T) were Gram-negative, yellow, aerobic and rod-shaped. The strain formed a distinct phyletic line with less than 91 % 16S rRNA gene sequence similarity to its closest relatives with validly published names within the class Gammaproteobacteria. The genomic DNA G+C content was 51.9 mol%. The major fatty acids were C(16 : 1)omega7c/iso-C(15 : 0) 2-OH, C(18 : 1)omega7c and C(16 : 0). Based on data from a polyphasic chemotaxonomic, physiological and biochemical study, strain QM42(T) is considered to represent a novel genus and species, for which the name Gilvimarinus chinensis gen. nov., sp. nov., is proposed. The type strain is QM42(T) (=CGMCC 1.7008(T)=DSM 19667(T)).

[Abundance and biomass of meiobenthos in Southern Yellow Sea in winter].

A two cruises investigation on the meiobenthos in the continental shelf of Southern Yellow Sea was made in January 2003 and January 2004. The results showed that the average abundance of meiobenthos was (954.20 +/- 269.47) ind x 10 cm(-2) and ( 1 186.12+/- 486.07) ind x 10 cm(-2), and the biomass was (954.38+/-403.93) microg x10 cm(-2) and (1 120.72+/-487.21 ) mg x 10 cm(-2) in January 2003 and January 2004, respectively, with no significant difference observed. A total of twenty meiobenthic groups were identified. Free-living marine nematodes was the most dominant group in abundance, with a relative dominance of 87% in 2003 and 90% in 2004, followed by benthic harpacticoids copepoda, polychaeta and kinorhyncha. In terms of biomass, the dominant groups were nematoda (34% -38%), polychaeta (25% -33%), ostracoda (9% -22%) and copepoda (8%). 96. 64% of the meiobenthos distributed in the top 0-5 cm of sediment, while 72. 48% of nematode and 89. 46% of copepoda were in the top 0-2 cm of the sediment. Meiobenthos biomass had significant correlation with the sand and silt contents of sediment and the content of Chl-a. The species composition and biodiversity analyses of six representative stations indicated that there were three meiobenthos communities in the study area, i. e. , inshore, cold waters mass, and transitional communities.

[Secondary productivity of macrobenthos in Jiaozhou Bay].

From September 2003 to September 2004, seven cruises bimonthly survey was conducted on the macrobenthos at five research stations in the Jiaozhou Bay, and the abundance, biomass, secondary productivity, and P/B value of the macrobenthos were studied by using Brey' s empirical formula. The results showed that the secondary productivity of the macrobenthos was averagely 47.34 g x m(-2) x a(-1), and the mean P/B value was 0.58. Correlation analysis indicated that Chl-a was the important environmental factor affecting the secondary productivity. A comparative study on the southern Yellow Sea, Bohai Bay and other areas also proved that on local scale, Chl-a was the important factor affecting the secondary productivity of the benthic community, but on regional scale, water depth was more determinative, i.e., this productivity was decreased with increasing water depth. The greatest contributor to the secondary productivity of macrobenthos in studied areas was Ruditapes philippinarum, the most important economic bivalve in the Jiaozhou Bay, and its population was dominated by the individuals with the ages of less than one year, one year, and two years.

Distinct effects of different concentrations of sodium selenite on apoptosis, cell cycle, and gene expression profile in acute promyeloytic leukemia-derived NB4 cells.

Selenium at a low concentration has a chemopreventive role against cancer, while at a high concentration, it exerts a direct antitumor effect. However, the mechanisms remain elusive. In this article, we discovered that Na(2)SeO(3) at 20 micromol/l concentration could significantly inhibit the proliferation of NB4 cells, affect the cell cycle distribution of cell population, and induce cellular changes characteristic of apoptotic cells, while this same compound at 2 micromol/l concentration had no such effects. The mechanisms underlying these overt differences caused by treatment of different concentrations of selenium were further investigated. cDNA microarray analysis showed that after treatment by 20 micromol/l Na(2)SeO(3), 34 genes were changed in expression, while treatment by 2 micromol/l Na(2)SeO(3) resulted in the changes of 29 genes. Nine genes were regulated in both groups, among which three showed opposite changes caused by 2 and 20 micromol/l Na(2)SeO(3). The majority of regulated genes did not coincide between the two experiment groups. In conclusion, 2 and 20 micromol/l Na(2)SeO(3) could have different effects on NB4 cells, and some genes might be involved in the underlying mechanisms. Our findings could provide basis for further uncovering the molecular mechanisms of the chemopreventive and antitumor effects of selenium and, in turn, for probing the rationality of treating leukemia with selenium.

Sodium selenite induces apoptosis in acute promyelocytic leukemia-derived NB4 cells by a caspase-3-dependent mechanism and a redox pathway different from that of arsenic trioxide.

Two relatively recent discoveries stand behind our current effort to investigate the effects of the chemopreventive agent, selenium, on the proliferation and survival of NB4 cells. The first is that certain selenium compounds such as sodium selenite have pro-oxidant ability to catalyze the oxidation of thiols and simultaneously generate superoxide. The second lies in the exquisite susceptibility of NB4 cells to arsenic trioxide-induced, reactive oxygen species (ROS)-mediated apoptosis due to less efficiency of the cellular defense system. In this study, we demonstrated that sodium selenite could induce apoptosis in NB4 cells via the classic mitochondrial pathway involving caspase-3 activation and Bcl-2 cleavage. An increase in the basal cellular glutathione (GSH) content rendered NB4 cells resistant to arsenic trioxide, but could sensitize NB4 cells to sodium selenite. Moreover, combined treatment of NB4 cells with all- trans retinoic acid (ATRA) at low concentration and sodium selenite exhibited a synergistic effect on apoptosis induction. Together, our results suggest that selenite is a promising candidate for treatment of acute promyelocytic leukemia (APL) and the mechanism underlying its anticancer effects warrants further investigation.

[Study of biological characteristics of the CD(34)(+) CD(59)(+) and CD(34)(+) CD(59)(-) cells from PNH patients' bone marrow].

OBJECTIVE: To explore the characteristics of CD(34)(+) CD(59)(+) cells from paroxysmal nocturnal hemoglobinuria(PNH) patients' bone marrow and the possible reasons of hematopoietic clonal dominance of PNH clones. METHODS: CD(34)(+) CD(59)(+) and CD(34)(+) CD(59)(-) cells from PNH patients and CD(34)(+) cells from normal control were selected from the bone marrow mononuclear cells by means of immunomagnetic microbead-flow cytometry two step sorting method undergone ex vivo expansion in liquid culture for two weeks and performed semisolid cultures before and after expansion. RESULTS: (1) Cultivation for seven days was the optimum for ex vivo expansion of PNH CD(34)(+) CD(59)(+) cells and normal CD(34)(+) cells, both cell populations remained CD(59) positive after expansion. (2) Normal CD(34)(+) cells had higher capacities of proliferation and expansion, and stronger potential to survival than that of both PNH CD(34)(+) CD(59)(+) and PHN CD(34)(+) CD(59)(-) cells. (3) In terms of semisolid culture, there was no significant difference in the yields of CFU formation between CD(34)(+) CD(59)(+) and CD(34)(+) CD(59)(-) cells. (4) In liquid culture with combinations of hematopoietic factors SCF + IL-3 + IL-6 + FL + Tpo or SCF + IL-3 + IL-6 + FL + Tpo + Epo, there was no significant difference in the capabilities of survival, proliferation and expansion between CD(34)(+) CD(59)(+) and CD(34)(+) CD(59)(-) cells; but with combination of SCF + IL-3 + IL-6 + FL + Tpo + Epo + GM-CSF, CD(34)(+) CD(59)(-) cells had better proliferation and expansion capacities and stronger potential to survival than that of CD(34)(+) CD(59)(+) cells. CONCLUSIONS: (1) Normal CD(34)(+) cells had better proliferation, expansion capacities and stronger potential to survival than that of PNH CD(34)(+) CD(59)(+)cells. (2) In semisolid and liquid culture with hematopoietic factor combinations, there was no significant difference in the capabilities of survival, proliferation and expansion between CD(34)(+) CD(59)(+) and CD(34)(+) CD(59)(-) cells. It was suggested that CD(34)(+) CD(59)(-) cells had no clonal hemotopoiesis dominance. GM-CSF might be one of the reasons for PHN clones to possess clonal hematopoiesis dominance.

Induction of apoptosis by sodium selenite in human acute promyelocytic leukemia NB4 cells: involvement of oxidative stress and mitochondria.

The mechanisms involved in the anti-carcinogenic activity of selenium remained to be elucidated. In the present study, we examined sodium selenite induced apoptosis and oxidative stress in human acute promyelocytic leukemia cell lines (NB4). Cell growth and viability were assessed by trypan blue exclusion and cell counting; apoptosis by DNA electrophoresis and analysis of intracellular DNA contents; reactive oxygen species and reduced glutathione in the cell were measured by lucigenin dependent chemoluminescent (CL) test and spectrophotometer; mitochondrial transmembrane potential was measured by flow cytometry. Sodium selenite could inhibit the growth and induce apoptosis of NB4 cells. Sodium selenite could increase the production of reactive oxygen species (ROS) in NB4 cells and decrease the level of intracellular reduced glutathione, but caused no change in the activity of antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx). Sodium selenite enhanced the collapse of mitochondrial transmembrane potential (MTP), in parallel with the production of ROS. Finally antioxidant N-acetylcysteine (NAC) could inhibit the ROS production, MTP collapse and apoptosis in NB4 cells. Our results suggested that sodium selenite could induce apoptosis of NB4 cells through mitochondrial change mediated by production of reactive oxygen species within the cells.

[Application of double immunomagnetic positive sorting to ex vivo expansion of marrow CD34(+)CD59(+) cells from patients with paroxysmal nocturnal hemoglobinuria].

Since flow cytometry was not feasible for sorting a huge amount of cells for clinical use, the method of double immunomagnetic positive sorting was used for selection of CD34(+)CD59(+) cells from bone marrow mononuclear cells in patients with paroxysmal nocturnal hemoglobinuria (PNH), which laid the groundwork for clinical ABMT/APBSCT of patients with PNH. Immunomagnetic positive selection was used for two times, the microbeads were removed from the CD34(+) cells selected firstly by means of overnight culture, then the sufficient CD34(+)CD59(+) cells were used for ex vivo expansion. The results showed that the survival, proliferation and colony-forming units of the selected CD34(+)CD59(+) cells by double immunomagnetic positive sorting had no significant difference as compared with that of CD34(+)CD59(+) cells selected by flow cytometry technique. It is suggested that the double immunomagnetic positive sorting promotes the use for separation and purification hematopoietic stem/progenitor cells and other cells with double or multiple markers cells for autologous hematopoietic stem cell transplantation in PNH patients.

[Proliferation and anti-tumor activity of lymphocytes and their effect on normal phenotype of autologous bone marrow hematopoietic cells in patients with paroxysmal nocturnal hemoglobinuria].

There is a hypothesis that paroxysmal nocturnal hemoglobinuria (PNH) hematopoitic stem cells are resistant to the cytotoxic effect of T cells because they lack glycosylphosphatidylinositol (GPI)-linked proteins. The aim of this study is to investigate proliferation and anti-tumor activity of lymphocytes in patients with PNH, and also to assay the effect on normal cell (CD59(+)) phenotype in bone marrow of PNH patient by autologous lymphocytes in vitro. MTT assay for detection of lymphocytes proliferation and its anti-tumor effect was driven to delineate T cell reactive function. The CD34(-) and CD34(+) bone marrow cells (selected by means of immunomagnetic method) as well as unsorted marrow cells in PNH patients were cultured together with autologous CD59(+) or CD59(-) lymphocytes, their cultured supernatant, extrinsic IFN-gamma and IL-2 in a liquid culture system. CD59(+) cells were counted by flow cytometry after 10 day culture in vitro. The results showed that there were no differences in the proliferation ability of lymphocytes between each group: controls 1.42 +/- 0.46, unsorted PNH lymphocytes 1.40 +/- 0.35, CD59(-) 1.30 +/- 0.40, and CD59(+) PNH lymphocytes 1.40 +/- 0.42. Anti-tumor effect of lymphocytes declined in PNH patients when compared with control [(50.00 +/- 28.67)% vs. (76.13 +/- 10.15)%]. The proportion of CD59(+) cells diminished significantly after culture with autologous lymphocytes, their supernatant, extrinsic IFN-gamma or IL-2 (P < 0.01) in groups of unsorted, CD34(+) and CD34(-) bone marrow cells. No significant difference was found between groups of CD59(-) and CD59(+) lymphocytes, or CD34(-) and CD34(+) marrow cells. It is concluded that turbulences of immune regulations may be involved in pathogenesis of PNH.

Detection of erythrocytes deficient in glycosylphosphatidyl-inositol anchored membrane proteins in patients with paroxysmal nocturnal hemoglobinuria by the toxin HEC secreted by Aeromonas hydrophila J-1.

OBJECTIVE: To study the feasibility of diagnosing paroxysmal nocturnal hemoglobinuria (PNH) with toxin HEC, the abbreviation of hemolytic, entreotoxigenicity and cytotoxity secreted by Aeromonas hydrophila J-1. METHODS: The crude toxin HEC was extracted from the culture medium of Aeromonas hydrophila J-1 by precipitating with saturated (NH(4))(2)SO(4) and then purified through DEAE52. Purified toxin HEC is different from Aerolysin in molecular weight and necessity of activation. Crude toxin is prepared possessed same effect as purified ones. This crude toxin was used to act on red blood cells (RBCs) from patients with PNH, non-PNH anemia, and normal persons. Absorbance at 630 nm was measured to quantitate the extent of hemolysis. Toxin HEC treated and untreated RBCs were both stained with anti-CD59 monoclonal antibody and FITC labeled goat-anti-mouse IgG. The percentage of CD59(+) cells was detected by flow cytometry (FCM). RESULTS: After toxin HEC treatment, RBCs from PNH patients showed resistance to the toxin hemolysis, which was negatively related to the percentage of CD59(+) cells, while RBCs from normal persons and non-PNH anemic patient were nearly totally lysed. CONCLUSION: Detection of RBCs resistance to toxin HEC can be used for the diagnosis of PNH.

Freeliving marine nematodes as a pollution indicator of the Bohai Sea.

A hierarchical diversity index--taxonomic distinctness index delta+, which was first defined by Warwick and Clark in 1998, was employed to evaluate the pollution status of the Bohai Sea with freeliving marine nematodes. The result showed that the Bohai Bay and other coastal sampling sites might be affected by oil and gas production and other anthropogenic influences. In other words, anthropogenic disturbance was affecting this component of the benthos in these locations. And most offshore sampling sites in the middle of the Bohai Sea were clear and unpolluted.

[Comparison of capabilities of survival, proliferation and expansion between CD34+CD59+ cells from patients with PNH and CD34+ cells from normal control].

OBJECTIVE: To explore in vitro expansion of CD34+CD59+ cells from patients with PNH, and compare the capabilities of survival, proliferation and expansion between CD34+CD59+ cells from patients with PNH and CD34+ cells from normal control. METHODS: CD34+CD59+ cells from patients with PNH and CD34+ cells from normal control were selected from the bone marrow mononuclear cells by means of two-step sorting method with immunomagnetic microbead-flow cytometry, then underwent in vitro expansion for two weeks and semi-solid culture in vitro before and after expansion. RESULTS: (1) CD34+CD59+ cells from patients with PNH can be expanded effectively in vitro, and the biggest expansion of CD34+CD59+ cells was about 23.49 fold on the 7th day. (2) There were some similar characteristics between CD34+CD59+ cells from patients with PNH and CD34+ cells from normal control, such as: the best combination of hematopoietic factors for in vitro expansion was SCF+ IL-3 + IL-6 + FL + Tpo + Epo, and the seventh day was the most suitable in course of 4-14 days for in vitro expansion, and after in vitro expansion, the cells remained CD59 positive and strong capability of performing colony-forming. (3) CD34+ cells from normal control had better proliferation, expansion and stronger potential to survive than CD34+CD59+ cells from patients with PNH. CONCLUSIONS: (1) In vitro expansion of CD34+CD59+ cells from patients with PNH can be performed. The present study showed the possibility of performing ABMT or APBSCT clinically for patients with PNH. (2) There were some similar characteristics between CD34+CD59+ cells from patients with PNH and CD34+ cells from normal control, but the latter had better proliferation, expansion and stronger potential to survive than the former. CD34+CD59+ cells from patients with PNH were not completely normal cells.

[A colorimetric method of HEC toxin hemolysis test for diagnosis of paroxysmal nocturnal hemoglobinuria].

The purpose of the study is to establish a colorimetric method of HEC toxin hemolysis test for diagnosis of paroxysmal nocturnal hemoglobinuria (PNH). RBCs from normal persons and patients with PNH and non-PNH anemia were treated with HEC toxin secreted by Aeromonas hydrophila J-1 strain and the absorbance at 630 nm was measured to quantitate the extent of hemolysis. The results demonstrated that the RBCs from PNH patients showed resistance to the toxin hemolysis, which was in accord with the percentages of CD59(-) cells, while the RBCs from normal persons and non-PNH anemic patients were nearly totally lysed. It is concluded that the method can be considered as a simple, specific and reliable method for the diagnosis of PNH.

[Inhibition of the activation of transcriptional factor NFkappaB during sodium selenite-induced apoptosis in NB4 cells].

In order to evaluate the effect of sodium selenite on the activation of NFkappaB during selenite-induced apoptosis in NB4 cells, Western blot was used to measure the level of P65 in nuclear extraction of NB4 cells treated with sodium selenite to reflect the activation of NFkappaB; the apoptosis of NB4 cells was determined by morphological observation, DNA ladder electrophoresis and flow cytometry; and MTT test was used to measure the growth inhibition of cells. Results showed that sodium selenite (>/=5 micro mol/L) suppressed the cell growth, induced apoptosis and inhibited the activation of NF kappaB in a concentration- and time-dependency pattern. It was concluded that inhibition of NF kappaB might be one of the mechanisms in selenite-induced apoptosis in NB4 cells.

[The comparison between the mechanisms of sodium selenite induced apoptosis and arsenic trioxide induced apoptosis in human acute promyelocytic leukemia cell line NB4 cells].

In order to explore the differences between the mechanisms of selenite-induced apoptosis and arsenic induced apoptosis in NB4 cells, growth inhibition was determined by MTT test, apoptosis determined by DNA electrophoresis and analysis of intracellular DNA contents, reactive oxygen species and reduced glutathione in the cell were measured by Lucigenin dependent chemoluminescent (CL) test and spectrophotometry, and mitochondrial transmembrane potential was measured by flow cytometry. The results showed that: 5 micro mol/L sodium selenite similar to 1 micro mol/L arsenic trioxide could induce the apoptosis of NB4 cells after treatment for 24 hours. Both could elevate the level of reactive oxygen species and intensify mitochondrial transmembrane potential collapse, accompanied with decrease of reduced glutathione centent. The effect of selenium selenite on these aspects was more significant than those of arsenic trioxide. Elevation of intracellular glutathione in N-acytlcysteine pretreated NB4 cells could enhance the selenite induced apoptosis and oxidative stress, but ameliorate the arsenic trioxide induced apoptosis and oxidative stress. It was concluded that sodium selenite and arsenic trioxide can induce the apoptosis of NB4 cells, but there are significant differences between the mechanisms of selenite-induced and arsenic-induced apoptosis in NB4 cells, particularly in the influence of intracellular glutathione content on the drug action.

[The effects of sera from patients with paroxysmal nocturnal hematoglobinuria on the growth of CD34(+) cells].

To investigate the effects of sera on the growth of single CD34(+) cells from patients with paroxysmal nocturnal hematoglobinuria (PNH), sera from both PNH patients and normal individuals were added separately to the single cell culture system and semi-solid colony formation system. The growth of the normal CD34(+) and PNH CD34(+) CD59(+) and CD34(+) CD59(-) cells was evaluated. No growth difference was found for growth of the normal CD34(+) and PNH CD34(+) CD59(+) cells when PNH or normal sera were added to the culture media in either single cell culture or colony formation culture. While no difference was detected for single PNH CD34(+) CD59(-) cells growth when PNH or normal sera were added, more colonies were observed in semi-solid culture with PNH sera. A conclusion was reached that compared with those from normal controls, the sera from PNH patients had no significant influence on single hematopoietic stem/progenitor cells derived from normal subjects and from PNH patients, but the PNH sera might promote the colony formation of the CD34(+) CD59(+) cells in semi-solid culture