An Improved Chemical Substitute for Fetal Calf Serum for the Micronucleus Test

The routine use of the micronucleus test in the mutagenicity evaluation of xe-nobiotics is limited by high cost and limited availability of fetal calf serum. On the other hand, there are disadvantages, such as hypotonic damage and clumping of cells, associated with the use of mineral medium substitutes for fetal calf serum. Alternatively, we recommend a chemical medium containing Hanks' buffered salt solution, 1% (w/v) bovine serum albumin, and 0.15% (w/v) ethylenediaminetetraacetic acid, final pH 7.4, to preserve morphology, density and homogeneity of bone marrow cells. Mast cell granules are efficiently removed from rat bone marrow preparations by washing twice with this medium. The morphological preservation of cells is further enhanced by fixation with 70 % (v/v) ethanol for 5 min. The proposed medium provides a cost-effective and convenient substitute for fetal calf serum with substantially improved quality of bone marrow preparations for the micronucleus test.     

Mesodermalizing Factors in Fetal Calf Serum

The inducing activities of fetal calf serum (FCS) and fetal calf serum heated for a short time (HFCS) were tested with early gastrula presumptive ectoderm of the newt, Cynops pyrrhogaster as a reactor. Inducing activity was measured by sitting-drop culture of pieces of ectoderm before and after treatment with Ca, Mg-free solution (CMF) in culture medium contained FCS or HFCS (10–50%) as inductor. Results showed that FCS did not induce mesodermalization of ectoderm, before or after treatment with CMF, and that HFCS induced mesodermalization only of ectoderm treated with CMF. The treated ectoderm cells differentiated into mesoderm cells such as muscle and notochord. The induction increased with increase in the duration of CMF treatment and with the concentration of HFCS in the medium. This indicates that FCS changes into mesodermalizing material when heated for a short time and that mesodermal induction by HFCS depends on some effect of CMF on presumptive ectoderm. Since CMF was found to be a neuralizing factor, activation of presumptive ectoderm with a neuralizing factor is probably a prerequisite for mesodermal induction with HFCS.     

Milk-clotting Enzyme from Irpex lacteus as a Calf Rennet Substitute for Cheddar Cheese Manufacture

The milk-clotting enzyme fraction from Irpex lacteus (IR) was obtained by affinity chromatography. To evaluate IR as a calf rennet substitute, Cheddar cheese-making trials were done. There was no difference in cheese yield, protein recovery, or fat recovery between cheese made with calf rennet (CR) and that made with IR. Although IR cheese showed a slightly higher extent of proteolysis in comparison to the control during ripening, IR cheese did not develop a bitter taste even after 6 months of ripening. These facts indicate that IR is a promising rennet substitute for cheese-making.     

Chromatographic Analysis of Gastrin-Releasing Peptide In Heat-Inactivated Fetal Calf Serum

Abstract. Gastrin-releasing peptide and the carboxyterminal fragments gastrin-releasing peptide [14-27] and [18-27] are found by radioimmunology and high performance liquid chromatography to be present in heat-inactivated fetal calf sera. Peptides containing the carboxyterminal sequence of gastrin-releasing peptide are known to display mitogenic activity. Thus, gastrin-releasing peptide represents a new class of mitogenic factors that are present in heat-inactivated fetal calf serum.     

微核直径测试作为非整倍体诱发剂的分析手段

以小鼠骨髓红细胞微核直径测试,比较了秋水仙素（COL）与昆明山海棠（THH）、对苯二酚（HQ）在哺乳动物体细胞中的非整倍体诱发效应。丝裂霉素C（MMC）作为多功能染色体断裂剂引入实验,为诱发非整倍体的阴性对照。结果发现,COL组,71%的微核直径（d）大于或等于所在细胞直径（D）的五分之一（d≥D/5）;THH诱发微核中,54%的微核d≥D/5;HQ及MMC组,分别有47%及14%的微核相对直径达此阈值。暗示THH及HQ具有类似COL的某种非整倍体诱发效应。微核直径测试可作为非整倍体诱发剂检测的辅助手段。 The relative diameters of micronucleus induced by colchicines(COL),Triptergium hypoglaucum(Level)Hutch(THH)and hydroquinone(HQ)were compared to evaluate their aneugenic activities in mouse bone marrow erythrocytes.MitomycinC(MMC)was taken as the negative control in the experiment because it is a multifunctional clastogen without aneugenic potential.Diameters of the cytoplasm(D)and the micronucleus(d)of each micronucleated erythrocytes were measured with a micrometer in a microscope.The frequency of relatively large micronuclei(d≥D/5)was found(71%) in COL treated group.In the THH and HQ treated groups,the relatively large micronuclei were 54% and 47%,respectively.Such micronuclei were infrequent(14%)in the MMC treated group.The results implied that THH and HQ may possess some aneugenic potential like COL.     

Antibody to Viruses Affecting Cattle in Commercial Tissue Culture Grade Fetal Calf Serum

Commercial fetal calf serum (FCS) for tissue culture use was tested for neutralizing activity against several viruses which affect cattle. Certain lots of FCS contained no neutralizing activity, whereas other lots contained neutralizing activity to several viruses. It was concluded that the neutralizing activity found in certain lots of sera was due to specific antibody and that its presence could be most easily explained by the contamination of the FCS with serum from postcolostral bovine serum. A nonantibody inhibitor to vesicular stomatitis virus was also found at low levels in most lots of serum. Because those sera which had antibody had antibody to several viruses, it was suggested that the use of the micro-serum neutralization test with a few bovine viruses which are widespread in the bovine population should be satisfactory to detect FCS which was contaminated with postcolostral bovine serum.     

Formol-Saline as A Cell Conserving Medium in the Micronucleus Test

It is widely recognized that tests using mammalian cell sytems are essential for assessing mutagenic hazard (Ishidate and Yoshikawa 1980). The micre nucleus test (Von Ledebur and Schmid 1973, Schmid 1973) is a convenient in vivo technique to overcome the shortcomings of in vitro bacterial methods. However, this assay requires high quality smears, for the production of which the solution used to avoid cell damage is critical.     

Sildenafil Citrate Increases Fetal Weight in a Mouse Model of Fetal Growth Restriction with a Normal Vascular Phenotype

Fetal growth restriction (FGR) is defined as the inability of a fetus to achieve its genetic growth potential and is associated with a significantly increased risk of morbidity and mortality. Clinically, FGR is diagnosed as a fetus falling below the 5^th centile of customised growth charts. Sildenafil citrate (SC, Viagra™), a potent and selective phosphodiesterase-5 inhibitor, corrects ex vivo placental vascular dysfunction in FGR, demonstrating potential as a therapy for this condition. However, many FGR cases present without an abnormal vascular phenotype, as assessed by Doppler measures of uterine/umbilical artery blood flow velocity. Thus, we hypothesized that SC would not increase fetal growth in a mouse model of FGR, the placental-specific Igf2 knockout mouse, which has altered placental exchange capacity but normal placental blood flow. Fetal weights were increased (by 8%) in P0 mice following maternal SC treatment (0.4 mg/ml) via drinking water. There was also a trend towards increased placental weight in treated P0 mice (P = 0.056). Additionally, 75% of the P0 fetal weights were below the 5^th centile, the criterion used to define human FGR, of the non-treated WT fetal weights; this was reduced to 51% when dams were treated with SC. Umbilical artery and vein blood flow velocity measures confirmed the lack of an abnormal vascular phenotype in the P0 mouse; and were unaffected by SC treatment. ¹⁴C-methylaminoisobutyric acid transfer (measured to assess effects on placental nutrient transporter activity) per g placenta was unaffected by SC, versus untreated, though total transfer was increased, commensurate with the trend towards larger placentas in this group. These data suggest that SC may improve fetal growth even in the absence of an abnormal placental blood flow, potentially affording use in multiple sub-populations of individuals presenting with FGR.     

细胞培养用牛血清污染大肠杆菌噬菌体的检测

用大肠杆菌噬菌体增殖法检测２１６批细胞培养用牛血清,结果１４２批（６５．７％）显示阳性结果。由此提示牛血清在采集制备过程中的污染严重,应引起重视。     

Fetal Calf Spinal Cords as Enriched Source of mRNA Encoding Glial Fibrillary Acidic Protein

Abstract: Total poly(A)⁺ RNA was isolated from fetal calf spinal cord, adult rat spinal cord, and young rat brain, and was translated using the rabbit reticulocyte lysate system. The amount of glial fibrillary acidic protein in the translation products was measured by immunoprecipitation with antiserum against glial fibrillary acidic protein. RNA from fetal calf spinal cord could direct glial fibrillary acidic protein synthesis such that this protein comprised approximately 1.4% of the total products. RNAs from adult rat spinal cord and brain could direct glial fibrillary acidic protein synthesis much less efficiently, with this protein comprising <0.3% of the total products. These results suggest that the gene for glial fibrillary acidic protein is strongly expressed in fetal calf spinal cord and that this tissue is an enriched source of mRNA encoding glial fibrillary acidic protein.     

Biochar as a Substitute for Vermiculite in Potting Mix for Hybrid Poplar

The purpose of this study was to evaluate biochar as a substitute for vermiculite in potting mixes for unrooted vegetative cuttings of hybrid poplar as represented by the clone ‘NM6’ (Populus nigra L. × Populus suaveolens Fischer subsp. maximowiczii A. Henry). We compared three treatments (peat moss (control), peat moss mixed with vermiculite, and peat moss mixed with biochar) at three times (pre-experiment, pre-fertilizer, and post-fertilizer). The biochar and vermiculite mixes had significantly higher cation exchange capacity (CEC) and pre-experiment exchangeable K than the control. Trees grown in the biochar and vermiculite mixes had significantly higher shoot K than the control at pre-fertilizer and post-fertilizer and significantly higher shoot and total biomass at post-fertilizer. The biochar mix was also associated with lower root biomass and higher shoot/root biomass ratio than the vermiculite mix at post-fertilizer. Vector analysis indicated that all treatments were deficient in N at pre-fertilizer, and the control was also deficient in K at pre-fertilizer and post-fertilizer. Linear regression confirmed that shoot biomass was strongly correlated (R²?=?0.97) with N and K uptake (in addition to initial cutting diameter), also, root biomass was strongly correlated (R²?=?0.96) with potting mix CEC (in addition to shoot biomass). Luxury consumption of K at pre-fertilizer indicates that the increases in shoot and total biomass observed with the biochar and vermiculite treatments arise from this nutrient being “pre-loaded” in both mixes. We conclude that biochar provides benefits equivalent to vermiculite in terms of key nutrient availability and total biomass productivity.     

Fetal and Newborn Calf Thymus as a Source of Chromatin Proteins: Purification of HMG-1 and HMG-2

The high mobility group (HMG) non-histone chromosomal proteins were first isolated from calf thymus' but were later found in numerous organs of many vertebrates.' The proteins can be extracted from calf thymus 1 with 0.35 M NaCl and they are quite soluble in 2% trichloroacetic acid. We have shown that members of the HMG-1 family (i.e., HMG-1, HMG-2, and HMG-E) exhibit a preferential affinity for single-stranded DNA at roughly physiological ionic trength. Members of this family have other intriguing properties (see references 6 and 7 for recent reviews), including the ability to assemble nucleosomes in vitroe8 The architecture of the proteins strongly suggests that they are designed to interact simultaneously with histones and with DNA through physically distinct domains^{6, 9}.