Reduction of ethylenediaminetetraacetic acid iron(III) by Klebsiella sp. FD-3 immobilized on iron(II, III) oxide poly (styrene-glycidyl methacrylate) magnetic porous microspheres: effects of inorganic compounds and kinetic study of effective diffusion in porous media.

Fe3O4 poly (styrene-glycidyl methacrylate) magnetic porous microspheres (MPPMs) were introduced to immobilize Klebsiella sp. FD-3, an iron-reducing bacterium applied to reduce Fe(III)EDTA. The effects of potential inhibitors (S(2-), SO3(2-), NO3(-), NO2(-) and Fe(II)EDTA-NO) on Fe(III)EDTA reduction were investigated. S(2-) reacted with Fe(III)EDTA as an electron-shuttling compound and enhanced the reduction. But Fe(III)EDTA reduction was inhibited by SO3(2-) and Fe(II)EDTA-NO due to their toxic to microorganisms. Low concentrations of NO3(-) and NO2(-) accelerated Fe(III)EDTA reduction, but high concentrations inhibited the reduction, whether by free or immobilized FD-3. The immobilized FD-3 performed better than freely-suspended style. The substrate mass transfer and diffusion kinetics in the porous microspheres were calculated. The value of Thiele modulus and effectiveness factors showed that the intraparticle diffusion was fairly small and neglected in this carrier. Fe(III)EDTA reduction fitted first-order model at low Fe(III)EDTA concentration, and changed to zero-order model at high concentrations.

[Y-chromosome microdeletions do not affect the outcomes of ICSI for infertile males].

OBJECTIVE: To compare the outcomes of intracytoplasmic sperm injection (ICSI) for infertile males with Y-chromosome microdeletions and for those with azoospermia or severe oligospermia but without Y-chromosome microdeletions. METHODS: We retrospectively analyzed 56 cycles of ICSI for 48 infertile cases with Y microdeletions (Group A) and 94 cycles for 90 cases with azoospermia or severe oligospermia but without Y-chromosome microdeletions (Group B) during the same period. We compared the two groups in the females' age, duration of infertility, males' age, number of oocytes retrieved, number of ICSI oocytes, fertilization rate, good embryo rate, number of embryos transferred, implantation rate, clinical pregnancy rate, abortion rate, live birth rate and babies' sexes. RESULTS: There were no significant differences between Groups A and B in the females' age, duration of infertility, males' age, number of oocytes retrieved, number of ICSI oocytes and number of embryos transferred (P > 0.05), nor in the rates of fertilization (69.0% vs 73.2%), good embryos (53.3% vs 48.7%), implantation (24.0% vs 30.3%), biochemical pregnancy (41.1% vs 44.7%), clinical pregnancy (37.5% vs 35.1%), early abortion (4.8% vs 6.1%) and live birth (35.7% vs 29.2%) (P > 0.05). CONCLUSION: Y-chromosome microdeletions do not affect the outcomes of ICSI. The affected couples should be informed of the necessity of prenatal genetic diagnosis before embryo implantation and the inevitability of vertical transmission to male offspring.

Identification and characterization of cul-3b, a novel hominine CUL-3 transcript variant.

AIM: To identify genes related to the human testis development by substrate hybridization technique. METHODS: A human testis cDNA microarray was constructed and hybridized with probes prepared from human adult and fetal testes and spermatozoa mRNAs by reverse transcription reactions. The differentially expressed genes were sequenced. And a newly identified cullin-3 (CUL-3) transcript variant (designated cul-3b) was bio-informatically analyzed with an online GenBank database. Multi-tissue reverse transcription polymerase chain reaction (RT-PCR) was used to determine the tissue expression profile of cul-3b. RESULTS: Cul-3b, a novel CUL-3 transcript variant, was identified. The expression level of cul-3b in adult testes was 3.79-fold higher than that in fetal ones. Cul-3b differed from cul-3 (including NM_003590 and AY337761) in the opening reading frame and had three internal ribosomal entry sites IRESes in the 5'-UTR. These led to a 24 amino acid (aa) truncation at N-terminus of CUL-3b as compared with CUL-3 and a more motivated expression pattern of cul-3b under some strict circumstances. Additionally, cul-3b expressed ubiquitously in human tissues according to multi-tissue RT-PCR. CONCLUSION: Cul-3b is a novel transcript variant of CUL-3, which may be important not only for the development of human testis but also for that of other organs.

[Microbial reduction of Fe(III) (EDTA) in the system of nitric oxide removal by metal chelate absorption].

Reduction of Fe(III) (EDTA) with cultivated microorganisms in the system of nitric oxide removal by metal chelate absorption was investigated. Supplemental glucose stimulates the formation of Fe(II) (EDTA) more than ethanol and methanol as the carbon sources. Ammonium salt was used to be as the nitric source instead of nitrate, which inhibits the reduction of Fe(III) (EDTA) due to the competition between the two electron acceptors. The optimal pH value was from 6 to 7. The reduction percentage of Fe(III) (EDTA) varied little with the range of 30 degrees C - 40 degrees C and decreased quickly with a temperature higher than 40 degrees C. The bio-reduction could be achieved efficiently with enough carbon source and cell inoculation. The reduction rate did not increase with adding more amount of carbon source or cell inoculation. The bio-reduction rate could be described by Michaelis-Menten equation and fitted to the first order reaction kinetics. The maximum reaction rates gamma max and the Michaelis constant k(m) were 1.3 mmol x (L x h)(-1) and 53.5 mmol x L(-1)respectively.