不同体系中甲烷水合物储气特性实验研究

为了研究不同体系甲烷水合物的储气特性,利用自行设计的小型水舍物合成装置,分别合成了一系列不同体系下的甲烷水合物（包括不同压力下的十二烷基硫酸钠（SDS）水溶液-甲烷体系、粉末冰-甲烷体系以及粉末冰-不同粒度砂-甲烷体系）;并采用真空容积法分别测定了三种不同体系条件下水合物样品的储气量;结合水合物生成动力学知识,探讨了不同反应时间、压力和环境介质对形成笼状结构水合物储气量的影响。结果表明,在SDS-水-甲烷体系中,相同的反应时间内,随着体系甲烷初始压力的增大,水合物储气量逐渐增大;冰粉-甲烷体系中,合成方式（静止或振摇）较初始压力对储气量影响更大;冰粉-沉积物-甲烷体系中。甲烷水合物储气量与沉积物粒度的变化无明显关系。     

On the effects of thiamphenicol and chloramphenicol on nucleic acid and protein synthesis in rabbit bone marrow cells in vivo and in vitro.

Besides the in vivo effects of thiamphenicol (TAP), this study shows the in vitro effects of TAP and D- and L-threo-chloramphenicol (CAP) on the synthesis of DNA, RNA, protein and hemoglobin in marrow cells and reticulocytes. The experiments make it likely that TAP exerts its action on a stem cell in a proliferating phase.     

Lysozyme levels in tissues of iron-deficient rats

Fats were fed either diets sufficient (300 ppm) or insufficient (5 ppm) in iron for 10 weeks. The iron-deficient animals had lowered hemoglobin and hematocrit levels and higher levels of kidney lysozyme activity than did control animals. There were no significant changes in serum and spleen lysozyme activity levels.     

Species-specific differences in the mitogenic activity of heparin-binding growth factors in the sera of various mammals

Sera from different mammalian species displayed great differences in mitogenic activity, as measured by stimulation of DNA synthesis in BALB/c 3T3 cells (3T3 cells). Among the sera examined, fetal bovine serum was least active, and increasing activity was detected in calf serum, human serum, rat serum and mouse serum, in that order. Rat and mouse sera exhibited extremely high mitogenic activity with 3T3 cells, but when TIG-1 human fetal lung fibroblasts were used for the DNA assay instead, the activity levels of all of the sera were lower, and the differences between them were smaller. To determine the reasons for these differences, the heparin-binding growth factors in each serum were separated on a heparin affinity column. Five peaks of DNA-stimulating activity were obtained. Three of these were found in all sera examined, with both 3T3 cells and TIG-1 cells. Two other peaks were found only with 3T3 cells; one was peculiar to rat and mouse sera, with extremely high activity in the rat, and the other was specific to fetal serum. The dependence of the activity of these peaks on the cells used for the test was confirmed using normal rat lung fibroblasts and immortalized rat kidney cells. These findings adequately explain the species-specific differences in mitogenic activity of whole sera, and the variation in activity depending on the cells used for assay of DNA synthesis.     

Species-specific differences in the mitogenic activity of heparin-binding growth factors in the sera of various mammals.

Sera from different mammalian species displayed great differences in mitogenic activity, as measured by stimulation of DNA synthesis in BALB/c 3T3 cells (3T3 cells). Among the sera examined, fetal bovine serum was least active, and increasing activity was detected in calf serum, human serum, rat serum and mouse serum, in that order. Rat and mouse sera exhibited extremely high mitogenic activity with 3T3 cells, but when TIG-1 human fetal lung fibroblasts were used for the DNA assay instead, the activity levels of all of the sera were lower, and the differences between them were smaller. To determine the reasons for these differences, the heparin-binding growth factors in each serum were separated on a heparin affinity column. Five peaks of DNA-stimulating activity were obtained. Three of these were found in all sera examined, with both 3T3 cells and TIG-1 cells. Two other peaks were found only with 3T3 cells; one was peculiar to rat and mouse sera, with extremely high activity in the rat, and the other was specific to fetal serum. The dependence of the activity of these peaks on the cells used for the test was confirmed using normal rat lung fibroblasts and immortalized rat kidney cells. These findings adequately explain the species-specific differences in mitogenic activity of whole sera, and the variation in activity depending on the cells used for assay of DNA synthesis.     

On the relationship of hemoglobin oxidation with the conformation of hemoglobin

Summary The rate of hemoglobin oxidation by various oxidants was studied under aerobic and anaerobic conditions, and the mechanism of hemoglobin oxidation was discussed in relation to the conformation of hemoglobin.     

Lysozyme levels in tissues of iron-deficient rats

Summary Rats were fed either diets sufficient (300 ppm) or insufficient (5 ppm) in iron for 10 weeks. The iron-deficient animals had lowered hemoglobin and hematocrit levels and higher levels of kidney lysozyme activity than did control animals. There were no significant changes in serum and spleen lysozyme activity levels.Supported in part by grant HL18712-02, Heart and Lung Institute, NIH.     

The effect of ligand on the kinetics of the sulfhydryl groups of human hemoglobin with p-mercuribenzoate

The rate of reaction of PMB with the masked sulfhydryls of human hemoglobin derivatives correlates well with the extent of dissociation for various ligands. It is suggested that the alpha1beta2 dimer of hemoglobin participates in the slow step of the reaction with PMB.     

Evolution of anti-Rh antibodies idiotypy in a blood donor over 9 years]

Anti-idiotypic sera were obtained in Rabbits immunized with Rh antibodies (isolated from the serum sample collected in 1974 from a Blood Donor). The sera agglutinate, at high titers, red cells coated with the immunizing antibodies and, at different titers, cells coated with antibodies from serum samples taken at other periods. Inhibition of hemagglutination of anti-idiotypic sera by different samples from the same Donor was complete with the immunizing serum and partial with other samples. These results show that idiotypes or idiotypic specificities appeared or disappeared during the period studied and represent the first observation on evolution of antibody idiotypy in Man.     

Cholinesterase in the atherosclerotic intima and in fibroblast cultures.

Cholinesterase activity was present in the atheromatous plaque of the rabbit's atherosclerotic aorta. Cholinesterase activity was significantly increased in rat fibroblast cultures grown in the presence of hypercholesterolemic serum. Cholesterol ester synthesis in these cultures was inhibited by neostigmine, a cholinesterase inhibitor.     

The protective effect of polyriboinosinic acid-polyribocytidylic acid against the occurrence of galactosamine-induced liver cell injury in rat

A marked increase of serum transaminase activities, histological changes of livers similar to those seen in viral hepatitis in man, and inhibition of hepatic protein synthesis were observed in rats following a single injection of D-galactosamine-HCl. These galactosamine-induced phenomena were prevented by the pretreatment of polyriboinosinic acid-polyribocytidylic acid 24 h before the galactosamine administration.     

Human serum as a culture medium for rat embryos

A comparison was made between the development of post-implantation rat embryos in human serum and rat serum. Protein synthesis (growth) and somite number (differentiation) were retarded in human serum and there was an increased frequency of neural tube defects. Male and female human sera supported development equally well.     

Human serum as a culture medium for rat embryos

Summary A comparison was made between the development of post-implantation rat embryos in human serum and rat serum. Protein synthesis (growth) and somite number (differentiation) were retarded in human serum and there was an increased frequency of neural tube defects. Male and female human sera supported development equally well.     

Differential removal of insulin-like growth factor binding proteins in rat serum by solvent extraction procedures

Solvent extraction of serum and other biological fluids at an acidic pH is a convenient method to remove the insulin-like growth factor binding proteins (IGFBPs); however, an incomplete removal of IGFBPs can occur and this can potentially interfere with the radioimmunoassay of insulin-like growth factors (IGFs). This study compared the removal of IGFBPs from normal adult rat serum and 5-day old neonatal rat serum by acid-gel filtration, and three solvent extraction methods, i.e., acid-ethanol (AE), acid-cryo-ethanol (ACE) and formic acid-acetone (FAA) treatments by western ligand blotting and slot-blotting analysis. In adult rat serum all three extraction methods removed nearly 75% of total IGFBPs present. For the neonatal serum, AE and FAA were very inefficient in eliminating the IGFBPs, while ACE was somewhat better, as it removed nearly 30% of IGFBPs. Ligand blots of extracted samples showed that IGFBPs of lower size range, 24 to 32 kDa (IGFBP-4, IGFBPs-1 and-2), were resistant to solvent extraction. Acid-gel filtration, in contrast, eliminated >95% of IGF-binding components in both sera. Determination of IGF-I concentrations in samples after gel filtration and extraction methods revealed lower IGF-I values in neonatal serum in acid extracted samples. These data caution against using solvent extractions for IGFBP removal in fetal/neonatal serum.     

Cholesterol synthesis in freshly isolated human leukocytes

Summary Cholesterol synthesis has been studied in human leukocytes shortly after the isolation from healthy subjects. Not delipidated human serum reduced the cholesterol synthesis when added to the incubation medium. A similar effect was obtained when the leukocytes were incubated in the presence of physiological concentrations of low density lipoproteins.     

Cholesterol synthesis in freshly isolated human leukocytes.

Cholesterol synthesis has been studied in human leukocytes shortly after the isolation from healthy subjects. Not delipidated human serum reduced the cholesterol synthesis when added to the incubation medium. A similar effect was obtained when the leukocytes were incubated in the presence of physiological concentrations of low density lipoproteins.     

Functional properties of lyophilized hemoglobin in the presence of amino acids after 13 months of conservation

Summary Four lyophilisates of hemoglobin, each protected by an amino acid salt, were conserved for 13 months. The determinations carried out (oxyhemoglobin, methemoglobin, p50, Hill's number, and visible spectrum) demonstrated that the hemoglobin had retained its functional properties.     

Allene versus acetylene in progestational steroids

In an attempt to find a side chain biologically superior to the common acetylene (e.g., 17alpha-ethynyl as in ethisterone, mestranol and ethinyl estradiol) for an orally active protestogen, 17alpha allene derivatives of norethindrone and mestranol were prepared and tested in the rabbit CLAUBERG assay, and in the rat vaginal smear assay. The minimal effective dose for norethindrone in the rabbit test was .05 mg sc for 5 days; .0025 mg for 17alpha-norethindrone-CH=C=CH2; and .005 mg for 17 alpha-norethindrone-C(CH3)=C=CH2. Similar increases in progestational activity were obtained in the antiestrogenicity and ovulation inhibiton tests. When a saturated carbon was inserted, as in 17alpha-norethindrone-CH(CH3)-CH=C=CH2, the beta allenyl derivative was completely inactive. The ED50 for mestranol in the rat vaginal smear assay (estrogenicity) was .003mg; for 17alpha-mestranol-CH=C-CH2 .01 mg; for 17alpha-mestranol-C(CH3)=C=CH2 .015 mg.     

Fetal calf serum alters cyclic adenosine 3',5'-monophosphate's effect on heme synthesis in vitro.

An investigation of the effect of cAMP on heme synthesis of rat bone marrow cells revealed that at 10(-2) M this cyclic nucleotide inhibits heme synthesis and that optimum stimulation occurs at 10(-4) M. Some unidentified constituent of fetal calf serum in the culture medium modifies the direction and degree of cAMP's effect.     

Hemoglobin catabolism and the killing of intraerythrocyticPlasmodium falciparum by chloroquine

To evaluate how chloroquine kills malaria parasites, hemoglobin catabolism was studied at the various stages of intraerythrocytic parasite development. We found that hemoglobin catabolism is switched off whenPlasmodium falciparum parasites mature to the late trophozoite or early schizont stages and is switched on again during the ring stage. When hemoglobin catabolism is switched off, the parasites are resistant to the morphologic effects of chloroquine. Although the ring stage parasites failed to mature in the presence of chloroquine, some of them switched on hemoglobin ingestion and became stuffed with hemoglobin-filled vesicles, indicating a distal block in catabolism. In fact, we demonstrated a high-grade block in hemozoin production during a 22 h incubation of synchronized ring forms; ferriprotoporphyrin IX (FP) incorporation into the -hematin of hemozoin decreased from 900 to 50 pmol/10⁶ parasitized erythrocytes. We propose that the primary effect of chloroquine on hemoglobin catabolism is to block FP polymerization to -hematin. Secondarily, toxic FP and FP-chloroquine complexes accumulate and are available to exert their several toxicities, which include inhibition of hemoglobindegrading proteases and membrane damage. As a consequence, maturation is arrested and eventually the parasites die and lyse.