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1.
Enzyme activity capable of converting the glycine-extended substance P precursor, substance P-Gly12, into substance P was purified from human cerebrospinal fluid. The conversion reaction was monitored by radioimmunoassay measurement of substance P formation. The chemical identity of the product was verified by reversed-phase HPLC. The enzyme reaction was stimulated by Cu(II) ion and ascorbic acid and inhibited by the presence of diethyldithiocarbamate. By HPLC molecular sieving, the major enzyme activity appeared as a protein of 26,000 molecular weight.  相似文献   
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The effect of transport stress on the plasma levels of catecholamines, Cortisol, and corticosteroid-binding globulin were studied in 6 gilts. To assess the effect on immune status, white blood cells were also counted and the cell-mediated immunity was estimated. The adrenaline level increased significantly during transport, from a basal mean level of 0.03 ng/ml to a plateau level of 0.11 to 0.12 ng/ml. The noradrenaline level fluctuated, but not constantly, during transport. The mean plasma Cortisol level before loading was approximately 40 nmol/1 and rose immediately after the start of transport to 70 nmol/1 (p< 0.05) and to 87 nmol/1 (p< 0.01) within 10 and 30 min, respectively. After unloading the Cortisol level rapidly decreased and a minimum level was seen 4 h after the transport, whereafter the diurnal rhythm was resumed. The plasma corticosteroid-binding globulin level increased nonsignificantly during the day of transport, from 25 nmol/1 to a level of 34 nmol/1, and it continued to increase until a plateau level was reached on the second day after transportation. The total white blood cell number increased significantly (from 13.7 to 15.5 × 109 cells/1), the number of lymphocytes decreased significantly (from 8.4 to 7.0 × 109 cells/1), and the number of polymorphonuclear neutrophils increased significantly (from 4.3 to 7.2 × 109 cells/1) during transport. No significant variation in the proliferation response was seen in the whole blood cell cultures. The main results were the significant signs of simultaneous activity of both the adrenal cortex and the adrenal medulla during transport.  相似文献   
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Isolation of human pituitary prolactin   总被引:1,自引:0,他引:1  
A process developed earlier for the extraction of human follitropin, lutropin, thyrotropin and growth hormone from homogenized frozen pituitaries provided a residue utilized for the isolation of prolactin. The isolation procedure involved extraction at pH 9.8, molecular sieve chromatography on Sepharose CL-6B, hydrophobic interaction chromatography on phenyl-Sepharose CL-4B, molecular sieve chromatography on Sephadex G-100 Superfine, and ion-exchange chromatography on DEAE-Sepharose CL-6B using a convex gradient. The progressive purification was guided by radioimmunoassays. The final product was obtained in yields of 31 microgram/gland, and was equipotent with a pituitary preparation (VLS-3) supplied by the National Pituitary Agency (NIH, Bethesda, U.S.A.). Contamination hormones negligible (less than 0.05%). No heterogeneity of the isolated prolactin was observed by sedimentation-equilibrium analysis in the ultracentrifuge, by SDS electrophoresis in polyacrylamide gel or by molecular sieve chromatography in 6 M guanidine hydrochloride. These different techniques gave values in the range of 21 000-23 000 for the molecular weight of prolactin. In free zone electrophoresis, and also in polyacrylamide gel electrophoresis the prolactin preparation was, however, heterogeneous and resolved at alkaline pH into three distinct components. The former technique permitted isolation and assay of the components, indicating that they were all fully active.  相似文献   
5.
Sex is a process of fusion of separate hereditary determinants. The advantages which could accrue from such fusions are protection against deleterious mutations and the possibility of combining favorable alleles into a single individual. If the fitness of the aggregate resulting from fusion is greater than its parts there will be strong selective pressure to perpetuate the aggregate in all progeny. Continued fusion presents problems though and new environmental conditions may occur which favor segregation. Segregation is also favored because of the existence of favorable recessive mutations. It is argued that the balance between these alternative goals of phenotype stability versus variety achieved an effective compromise with the development of the meiosis-fusion-mitosis cycle.  相似文献   
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To establish the importance of fluorescein diacetate (FDA) as a viability stain for cultured hepatocytes. we hypothesized that FDA staining would correlate positively with hepatocyte viability and function. Mixtures of live and dead cells were stained with FDA and scanned by flow cytometry. A close correlation was observed between the live cell fraction and percent viability as determined by FDA staining (R2 = 0.962). Hepatocytes were also sorted into low fluorescence and high fluorescence groups. Both albumin production and lidocaine metabolism (P-450 activity) were significantly increased in the high fluorescence group compared to the low fluorescence group. An automated, fluorescence-activated assay was useful for rapid assessment of hepatocyte viability. In addition. the intensity of green fluorescence following staining with FDA correlated well with two specific measures of hepatocyte function.  相似文献   
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Personalized medicine allows the selection of treatments best suited to an individual patient and disease phenotype. To implement personalized medicine, effective tests predictive of response to treatment or susceptibility to adverse events are needed, and to develop a personalized medicine test, both high quality samples and reliable data are required. We review key features of state-of-the-art proteomic profiling and introduce further analytic developments to build a proteomic toolkit for use in personalized medicine approaches. The combination of novel analytical approaches in proteomic data generation, alignment and comparison permit translation of identified biomarkers into practical assays. We further propose an expanded statistical analysis to understand the sources of variability between individuals in terms of both protein expression and clinical variables and utilize this understanding in a predictive test.  相似文献   
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Test fishing with multimesh gillnets was performed in 103 acidified Swedish lakes before and 2–4 years after liming. In a subset of 39 lakes additional test fishing was carried out 5–9 years after liming. Taking into account the sampling biases due to differences between water temperature and number of nets used on different sampling occasions, an increase of the total CPUE, the number of species caught and recruitment of dominating species was evident after liming. Decreased recruitment was found for perch (Perca fluviatilis) at a pH below 5.2 and for roach (Rutilus rutilus) at a pH below 6.1. During the acidification phase and 2–4 years after liming acid-tolerant perch dominated the lakes, but when a longer time had elapsed after liming species dominance shifted and acid-sensitive planktivorous species increased in CPUE while perch decreased.  相似文献   
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Effects on the aquatic biota of lime (CaCO3) application in acidified lakes and streams were studied in a number of waters. After treatment, lime-sensitive species of mosses (Sphagnum spp.) decreased, but species such as Potamogeton natans and Myriophyllum alterniflorum seemed to be favoured. A few years after liming species composition and diversity of phytoplankton, zooplankton and benthic insect larvae were almost identical to that found in oligotrophic and non-acid lakes. Molluscs and benthic crustaceans may have difficulties recolonizing. Reproduction of remaining species of fish was successful as soon as pH increased. High survival of larvae and fry can result in some extremely rich year classes with slow individual growth. In most cases restocking of depleted fish stocks was successful.  相似文献   
10.
A dynorphin B converting enzyme previously purified from bovine spinal cord was subjected to column electrophoresis in agarose suspension. By this technique combined with HPLC gel filtration it was possible to resolve and recover several isoforms of the proteinase. All these isoenzymes were associated with a similar molecular size but apparently they differed with regard to their net charges. No significant difference between their inhibitory profiles or their Km values for the release of Leu-enkephalin-Arg6 from dynorphin B was observed.  相似文献   
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