Specific sHLA in healthy donors and donor-specific sHLA in renal transplant patients.

We studied cadaver kidney transplant recipients to determine if their serum levels of donor-specific class I sHLA correlated with graft outcome. Testing of sHLA was performed by an ELISA sandwich assay using allospecific monoclonal trapping antibodies and anti-beta2-mu detecting antibody. Sufficient sHLA sensitivity (<1 ng/ml) was achieved by using two synergistic trapping antibodies. Suitable antibodies were available for A2 and B7, and data were collected for these two antigens. Stability of these sHLA was determined in plasma and serum as were ranges of normal and background levels. Background levels varied substantially. Five A2- recipients of A2+ grafts and 5 B7- recipients of B7+ grafts were studied with appropriate sHLA levels measured pre-transplant and at intervals post-transplant. Graft outcome was assessed by serum creatinines, renal biopsies and/or therapy for rejection. In the 5 patients (3 A2- and 2 B7-) whose post-transplant donor-specific sHLA never exceeded immunological complications (e.g., post-operative ATN, ureteral obstruction) did not affect the correlation. In the 5 patients with post-transplant levels exceeding pre-transplant levels, subsequent evidence of rejection was observed. Periodic measurement of donor-specific sHLA should be a useful instrument for monitoring renal allograft rejection.     

适合人肌母细胞的无血清培养基

背景：肌母细胞体外培养大多使用添加胎牛血清培养基,存在很多不足,开发无血清培养基,更加稳定、安全、经济,有广泛的应用前景。 目的：初步探索适合人肌母细胞培养的无血清培养基。 方法：配制含胎牛血清培养基 (DMEM/F12 1∶1添加胰岛素样生长因子1、碱性成纤维细胞生长因子和体积分数20%胎牛血清),间充质干细胞无血清培养基组(无血清培养基、2%血清替代物、2 mmol/L L-谷氨酰胺,人脐带间充质干细胞,细胞纯度大于99%,UltraCULTURETM添加血清替代物,谷氨酰胺)。自制无血清培养基组(GibcoTM添加胰岛素样生长因子1,碱性成纤维细胞生长因子,谷氨酰胺)。3种培养基分别对人肌母细胞分别进行培养,观察肌母细胞的形态、免疫组织化学的鉴定,计算克隆的形成率,绘制细胞生长的曲线,MTT检测肌母细胞的活性,比较3种培养基培养肌母细胞增殖、分化的差异。 结果与结论：各组细胞形态上无明显差异;各组免疫组织化学鉴定肌母细胞纯度均达99%;含胎牛血清培养基组和自制无血清培养基组克隆形成率显著高于间充质干细胞无血清培养基组(P < 0.01),含胎牛血清培养基组克隆形成率显著高于自制无血清培养基组(P < 0.01);含胎牛血清培养基组与自制无血清培养基组细胞数远高于间充质干细胞无血清培养基组;自制无血清培养基组细胞活性显著高于含胎牛血清培养基组和间充质干细胞无血清培养基组(P < 0.01)。自制无血清培养基组可有效用于肌母细胞的培养,在促进肌母细胞早期贴壁、增殖上还需进一步优化。  中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程      

无血清原代培养人前脂肪细胞并诱导分化

目的无血清原代培养人前脂肪细胞并诱导其分化为成熟脂肪细胞。方法采用胶原酶消化法分离并原代培养人前脂肪细胞,通过对细胞形态学的观察、油红O染色,以及脂肪细胞标志性酶G-3-PDH活性的测定对细胞进行鉴定。结果摸索出无血清培养并诱导人前脂肪细胞分化为成熟脂肪细胞的条件。在无血清的基础培养基中前脂肪细胞能够维持增殖。无血清分化培养基培养4d后细胞形态逐渐变圆,并出现球性脂滴,脂滴的数量逐渐增多至分化培养的第21天到达顶峰。结论在无血清培养的状态下成功诱导前脂肪细胞向脂肪细胞的分化,以作为激素或细胞因子对前脂肪细胞增殖或分化影响的研究基础。     

Lymphocyte culture in solid medium: I. Phytohaemagglutinin stimulation of human blood lymphocytes in chicken plasma clot cultures

Normal human blood lymphocytes were cultured in chicken plasma clots with a series of PHA-P dilutions. In this situation direct cell-to-cell contact was prevented, and thus a morphological estimate of the actual number of PHA responsive cells was possible in the absence of any cell-to-cell co-operation which might be mediated via cell contact. The distorting effects of transformed cell proliferation on quantification, and of death of the original small lymphocyte population, were similarly obviated. Between 9 and 20 per cent of those lymphocytes separated by methylcellulose and iron were PHA responsive at the optimal dose of PHA-P.     

Long-term culture of neurones from human cerebral cortex in serum-free medium

A method for cultivating neurones from the fetal human central nervous system in the absence of glial cells is described. Brain cells from 15-18-week-old human fetuses are plated on polylysine-coated surfaces and grown in a serum-free hormonally-defined medium. About 98% of the cells were identified as neurones using tetanus toxin as a marker. The cultures survive for up to 7 weeks and develop an extremely complex network of neurites.     

Expression of the CD46 antigen, and absence of class I MHC antigen, on the human oocyte and preimplantation blastocyst.

Expression of CD46 and class I major histocompatibility complex (MHC) antigens by human oocytes and 6-8-day unhatched expanded preimplantation blastocysts has been studied by immunocytochemistry. The CD46 antigen, a cell surface complement regulatory protein, was expressed by unfertilized oocytes as well as strongly by both the inner cell mass and trophectoderm of preimplantation blastocysts. In contrast, class I MHC antigens were not usually expressed by either oocytes or blastocysts. These data support the concept that gametes and embryonic cells involved in fertilization and early implantation events, respectively, may be protected from immunological recognition or attack both by the lack of class I MHC antigens and by expression of the CD46 complement regulatory protein.     

A solid medium for culture and identification of human T-mycoplasmas.

A solid urea-containing medium buffered to pH 6.5 with a suitable mixture of KH2PO4 and Na2HPO4 produced enlarged T-mycoplasma colonies containing a white precipitate. This was absent from M. hominis colonies. The medium can be used for the isolation and identification of T-mycoplasmas.     

Epidermal growth factor combined with recombinant human chorionic gonadotrophin improves meiotic progression in mouse follicle-enclosed oocyte culture

Using a mouse early preantral follicle culture system, mature full grown oocytes, arrested in prophase I of meiosis, were produced after 12 days using a recombinant gonadotrophin-supplemented medium. This culture medium does not mimic the normal extracellular environment of the oocyte and might therefore modify meiotic regulation and more particularly progression to metaphase II (MII). The aim of this study was to optimize the treatment using recombinant stimulatory ligands which were known to induce germinal vesicle breakdown (GVBD) and completion of meiosis I, metaphase II (MII), namely recombinant follicle stimulating hormone (r-FSH), chorionic gonadotrophin (r-HCG) and epidermal growth factor (EGF). Full-grown intrafollicular oocytes could not resume meiosis when the 'ovulatory' stimulus was r-FSH, used at a 100 times higher dose than during culture. r-FSH did not increase progesterone production. When 1.5 IU/ml r-HCG was used as meiotic trigger, germinal vesicle breakdown was obtained in 95% of the oocytes 64% of which extruded a first polar body. r-HCG induced a dramatic increase in progesterone production. When EGF was administered as sole stimulus on day 12 to the attached follicle-enclosed oocytes, only doses > or =5 ng/ml could cause GVBD, although less effectively than r- HCG (45 versus 95%; P < 0.0001). Oocytes undergoing GVBD by the EGF pulse reached metaphase II at a rate of 54% (not significant versus r- HCG). EGF did not stimulate progesterone production. Addition of increasing doses of EGF (0.5; 5; 10; 50 ng/ml) to r-HCG did not increase the GVBD-rate, but EGF doses >5 ng/ml improved MI to MII transition (P=0.027), thereby improving the final yield of MII oocytes by 12.5%. These data show that up to a dose of 50 ng/ml, EGF on its own could only override the somatic inhibitory stimuli in less than half of the cultured follicles. However, in addition to HCG, EGF (25 ng/ml) had a stimulatory effect on completing the first meiotic division. It was concluded that, under the present culture conditions, EGF in combination with HCG provided optimal nuclear maturation.      

New polymorphic microsatellite markers in the human MHC class I region

The human major histocompatibility complex (MHC) class I region is believed to contain a large number of genes encoding susceptible factors for diseases such as Behcet's disease, Graves disease and psoriasis vulgaris. To identify the causative genes of those diseases, we have conducted large-scale genomic sequencing and determined the 1.8 Mb entire HLA class I region from the MICB gene to the HLA-F gene. During the course of genomic sequencing, a total of 731 microsatellite sequences with dinucleotide to pentanucleotide repeats were found in this region. Previously, we reported that 26 microsatellites between MICB and S on the most centromeric side of the class I region, and between HSR1 and HLA-92/L in the midst of the class I region were highly polymorphic, and served as excellent genetic markers. In this paper, in order to fill the gaps with no known polymorphic microsatellites available in the HLA class I region, 12 new polymorphic microsatellite markers were recruited from the 1.8 Mb region including the remaining class I segments, namely between S and HSR1, and between HLA-92/L and HLA-F The average number of alleles at these new microsatellite loci was 8.2 with a polymorphism content value (PIC) of 0.63. These 38 markers in total almost uniformly interspersed in the HLA class I region will enable us to search precisely for the location of disease susceptible loci within the HLA class I region by association and for linkage analyses.     

A new selective medium for the culture of clostridia from human faeces

A new selective medium, sulphite-polymixin-milk (SPM) agar, for the isolation of clostridia from faeces is described. This medium contains whole cow's milk, which favours the growth of clostridia over that ofBacteroides andBifidobacterium spp., and only small amounts of colistin (10μg/ml) for suppressing growth of coliforms. The alkaline end-products of clostridia give rise to yellow colonies on a red background which are easy to distinguish from the red colonies of other not completely inhibited bacteria. The medium is suitable for isolation of many clostridia species. Comparisons were made between SPM and several other media for recovery of clostridia. The detection limit on SPM agar was more than 10³ below that on Reinforced Clostridia Agar (Oxoid CM101).     

Dimeric inhibins and activin A in human follicular fluid and oocyte-cumulus culture medium.

The concentrations of inhibin A, inhibin B and activin A in follicular fluid and oocyte culture medium were analysed to investigate the production of these peptide hormones by ovarian granulosa cells and oocyte-cumulus complexes, as well as their potential as possible biochemical markers for oocyte quality and fertilizing capacity. Follicular fluids were collected from individual follicles during oocyte retrieval for in-vitro fertilization (IVF). Oocyte-cumulus culture media were collected after in-vitro insemination. The concentrations of dimeric inhibin A, inhibin B and activin A were measured using two-site enzyme-linked immunosorbent assays in the follicular fluid and matched oocyte culture medium. Hormone concentrations were compared with oocyte quality and fertilizing capacity. The concentration of inhibin A in follicular fluid increased while that of inhibin B decreased with increasing follicle size. Follicular fluid concentrations of inhibin A inhibin B and activin A were not significantly different in follicles with differing oocyte quality. Oocyte culture medium concentrations of activin A were significantly higher in morphologically good quality oocytes. There was no relationship between the concentrations of the three hormones and oocyte fertilizing capacity. This study confirms that follicular fluid concentrations of inhibin A may prove to be a marker of follicular growth and maturation. Higher concentrations of activin A produced by good quality oocyte-cumulus complexes suggest that activin A may play a role in oocyte maturation.     

Intracellular pH regulation in the human oocyte

We have used fluorescence techniques to study the regulation of intracellular pH during fertilization and preimplantation embryo development in human oocytes. The intracellular pH of human oocytes during maturation and fertilization was always 7.4, suggesting that these processes do not involve long-term changes in intracellular pH. The recovery of intracellular pH of human oocytes and embryos after extracellular acid or alkaline shock was investigated. Fresh metaphase II oocytes and preimplantation embryos showed similar rates of recovery following alkaline shock. However, aged and immature oocytes had a significantly slower rate of recovery to physiological pH. Early embryos up to the morula stage were unable to recover following acidosis, whereas blastocysts could control both acidosis and alkalosis. We assessed the sensitivity of fertilization and early development in the human to extracellular pH. Our results show that insemination in the human is pH-sensitive, whereas intracytoplasmic injection (ICSI) activated oocytes at all pH tested. We suggest that this is due to the pH-sensitivity of the sperm-zona pellucida interaction, which is bypassed during the ICSI procedure. Further development in human embryos is more sensitive to alkalinity than acidity. We discuss these results in terms of the extracellular pH in vivo in the female reproductive tract.      

New blood culture medium.

A growth medium with a specific oxidation-reduction potential containing peptone, dextrose, sodium succinate, sodium lactate, gelatin, sodium bicarbonate and blue tetrazolium, an indicator dye, in a tris(hydroxymethyl)aminomethane buffer was used to detect the presence of microorganisms in blood. The procedure involved the introduction of blood (and bacteria) into the growth medium with the dye in its colorless state. As the bacteria grew, they converted the dye to a visible blue color (formazan) with their reductases. The growth medium served as its own contamination control, since microbial growth and be detected by a color change before it was used for blood culture. The experiments described herein demonstrate that the composition of this medium (with the dye) provides a unique system that is able to make a reliable and rapid detection of both gram-positive and gram-negative microorganisms and yeasts (Candida albicans) commonly associated with bacteremia.     

Erythroid stem cell culture in serum-depleted medium

Summary Techniques are described for the culture of multipotential, primitive, and mature mammalian erythroid colony-forming stem cells obtained from bone marrow, spleen, blood, or fetal tissues in semisolid cultures under defined, serum-deprived growth conditions. Inasmuch as colony formation is critically dependent on the presence of tissue-specific growth factors, the addition of purified recombinant interleukin-3 and erythropoietin affords the opportunity to examine the specific growth requirements of undifferentiated hematopoietic cells in a critical and quantitative manner through terminal differentiation for extended periods of time.     

Secretion of genetically engineered human/mouse class I antigens

Two soluble, secreted forms of HLA-B7 were engineered by the creation of hybrid human/mouse molecules containing the polymorphic 5' region of the HLA-B7 gene and the secretory 3' region of the mouse Q10d gene. The hybrid, designated F1, is the first construct with only human extracytoplasmic domains, consisting of exons for the leader peptide and the three extracellular domains (alpha 1, alpha 2, alpha 3) of B7 spliced to the exons for the Q10d truncated transmembrane and 3' untranslated (3'UT) sequences. The second construct, designated C2, is similar but has the human alpha 3 replaced by the Q10 alpha 3 domain. Protein product from each construct was best demonstrated after gene transfection into the J27.2 cell line. In particular, secretion of the F1 product proves that the Q10 alpha 3 domain is not necessary for secretion of class I/Q10 hybrids. Moreover, the two soluble B7 forms, which differ only in their alpha 3 domain, are similarly recognized by monoclonal antibodies W6/32 (anti-HLA-ABC), BBM.1 (anti-human beta 2 microglobulin), and allo-B7-antibody, but differentially recognized by monoclonal antibody Q1/28 (anti-HLA class I heavy chain). Production of such soluble hybrid class I molecules in large amounts should allow critical structural and functional studies of these proteins.