Purification and substrate specificity of BcmI restriction endonuclease

A strain producing the new specific restriction endonuclease BcmI has been found in the Bacillus generum. The enzyme has been purified by chromatography on the blue sepharose, phosphocellulose PII, heparin sepharose. The analogous purification has been obtained when the blue sepharose has been substituted for the orange sepharose, the home produced sorbent. The BcmI enzyme has been shown by the substrate specificity definition to be an isoschizomer of the restriction endonuclease ClaI.     

一种植物生长激素-N'-(5-硝基-2-羟基苯亚甲基)-3,5-二羟基苯甲酰肼的合成、晶体结构和抗菌活性

目的:合成并表征一种属于植物生长激素的席夫碱类化合物.方法:由5-硝基水杨醛和3,5-二羟基苯甲酰肼在甲醇溶液中反应得到N′-(5-硝基-2-羟基苯亚甲基)-3,5-二羟基苯甲酰肼.结果:用单晶X-射线衍射法测得其结构并表征,同时通过抗菌实验证明其在一定浓度下具有明显的抗菌活性.结论:这种席夫碱类化合物在某种程度上具有明显的抗菌活性.     

Structural and functional aspects of the heart ventricle myoglobin of bluefin tuna

The heart ventricle myoglobin of bluefin tuna has been purified to an apparent homogeneity. The amino acid analysis has revealed only a limited number of substitutions between the myoglobins of yellowfin and bluefin tuna. The alpha-helix content of tuna myoglobin has been found considerably lower than that of mammalian myoglobin. No correlation has been discovered between the conformational stability and alpha-helix content. Denaturation experiments have shown that the whole structure of tuna myoglobin results from the interaction of two structural units which represent the product of independent folding processes. The structure of tuna myoglobin has been found more open and disorganized than that of sperm whale. This result has been related to the low content of electrostatic interactions and explained in terms of evolutive adaptations.     

Breast augmentation using the expander mammary prosthesis

The expandable mammary prosthesis that has been successfully used for breast reconstruction has been modified for breast augmentation procedures. A new microreservoir that can be buried subcutaneously for extended periods has been developed. The unique design of this implant allows its size to be adjusted postoperatively as many times as desired, thus eliminating the possibility of a second operation to replace an implant whose size is unsatisfactory. Accurate, aesthetically satisfactory results are possible because the volume adjustments are made after the swelling has decreased and the implant has settled into position. Almost all patients offered this opportunity requested postoperative volume adjustments. The results of 59 patients are reported. The surgery was performed over a 3-year period, with the average follow-up time being 6 months. The incidence of capsular contracture has been less than 10 percent. Leakage was a problem in the original implant design; however, since the introduction of the new valve, there has been no leakage to date.     

Localization of the DNA segment coding for the synthesis of fraction I on the pYT plague pathogen plasmid]

Fragmentation of the pYT plasmid of the plague pathogen by ten restriction endonucleases has been studied. The evidence has been obtained in support of the possible presence of the movable genetic element containing a HindIII site within the plasmid pYT. The gene encoding the I fraction of the plague pathogen has been cloned. The physical map of the pYT plasmid has been constructed with the use of restriction endonucleases BamHI, XhoI, BstEII, SmaI, EcoRI, and HindIII. The fragment of the plasmid DNA coding for the synthesis of the plague pathogen fraction I has been mapped.     

Guanylate cyclase in E. coli. III. Purification and possible physiological role of GTPase]

A phosphohydrolase with a preferential activity for GTP has been isolated and partially purified from E. coli extracts. The enzyme purification has been achieved through precipitation by ammonium sulfate and chromatography on DEAE-cellulose, DEAE-Sephadex, Ultragel and a second DEAE-cellulose column. The phosphohydrolase activity is poly (C) dependent. The chromatographic analysis on PEI-cellulose has shown that the main product of GTP hydrolysis is GDP. The possibility that the enzyme partially purified in this work has an important role in the control of GTP availability as substrate for guanylate cyclase into the cells has been discussed.     

Characteristics of Symmetric Surface Plasmon Polariton Mode in Glass–Metal–Glass Waveguide

The propagation characteristics of symmetric surface plasmon polariton mode in a glass–metal–glass waveguide are presented. Gallium lanthanum sulfide has been taken as the glass and silver (Ag) has been used as the metal. The analysis has been done both numerically and analytically. A two-dimensional finite-difference time-domain-based simulation model has been developed in order to analyze the propagation characteristics numerically. The obtained results using numerical and analytical methods have been compared and a very good agreement has been found.     

Oligonucleotide derivatives in the nucleic acid hybridization analysis. II. Isothermal signal amplification in process of DNA analysis by minisequencing

The isothermal amplification of reporter signal via limited probe extension (minisequencing) upon hybridization of nucleic acids has been studied. The intensity of reporter signal has been shown to increase due to enzymatic labeling of multiple probes upon consecutive hybridization with one DNA template both in homophase and heterophase assays using various kinds of detection signal: radioisotope label, fluorescent label, and enzyme-linked assay. The kinetic scheme of the process has been proposed and kinetic parameters for each step have been determined. The signal intensity has been shown to correlate with physicochemical characteristics of both complexes: probe/DNA and product/DNA. The maximum intensity has been observed at minimal difference between the thermodynamic stability of these complexes, provided the reaction temperature has been adjusted near their melting temperature values; rising or lowering the reaction temperature reduces the amount of reporting product. The signal intensity has been shown to decrease significantly upon hybridization with the DNA template containing single-nucleotide mismatches. Limited probe extension assay is useful not only for detection of DNA template but also for its quantitative characterization.     

Cortisone-induced small RNP tightly bound to chromatin

The small nuclear RNP (alpha-RNP) tightly bound to chromatin has been isolated. alpha-RNP can be removed from chromatin together with the acid-soluble proteins. The RNA from this RNP has been isolated; its electrophoretic mobility is equal to that of 4 S RNA. The study of the resistance of alpha-RNA to RNases (A, T1 and S1) in salt solutions of various ionic strengths allows us to conclude that the alpha-RNA has a well-developed secondary structure. The alpha-RNA is tightly associated with the protein moiety of alpha-RNP and has developed secondary structure. The alpha-RNA is tightly associated with the protein moiety of alpha-RNP and has a high metabolic activity.     

Designing redox metalloproteins from bottom-up and top-down perspectives

The design of redox-active metalloproteins has been approached from two different directions. The de novo design approach has recently reached an important stage, at which structural information on several different designed metalloproteins has been obtained. This new information highlights the real challenge of this approach. The alternative approach involving re-engineering of evolved proteins has also made significant advances recently.     

Epidemiological assessment of the microbial contamination of the breast milk of healthy women

The qualitative and quantitative composition of the microflora of human milk has been studied. The dynamics of the occurrence of different microorganisms constituting the microflora at different periods of lactation has been established. The connection between the appearance of septic purulent infections in infants and the microbial contamination of milk has been revealed. The presence of Staphylococcus aureus in human milk in an amount of 500 microbial cells/ml has been found to constitute no menace to healthy infants.     

Multipurpose Intensive Care Unit in a District General Hospital

The advantages of a four-bedded purpose-built general intensive care unit in a district general hospital are described. In addition to 1,447 inpatients treated between January 1968 and December 1971 the unit was used to conduct outpatient investigations. This has filled an important gap in conventional arrangements, and is practical and economical. The unit has proved to have advantages, not only for seriously ill patients but also has benefited the hospital in other ways. It has been of material assistance in recruiting and training nursing and medical staff and has been welcomed and supported by patients and their relatives. It has also attracted practical support from voluntary organizations whose generosity has enabled much additional equipment to be purchased.     

Amino acid composition and physico-chemical properties of bluefin tuna (Thunnus thynnus) myoglobin.

1. The heart ventricle myoglobin of Atlantic bluefin tuna has been purified and its amino acid composition has been determined. 2. The perturbing effect of guanidine hydrochloride on the molecular structure of tuna ferrimyoglobin and its corresponding apoprotein has been investigated by Soret absorbance and ultraviolet fluorescence. 3. The conformation-free energy of unfolding delta G0 has been calculated by thermodynamic treatments of the data concerning guanidine unfolding. 4. The results have been compared with other known myoglobins, particularly those of yellowfin tuna.     

Transmission acoustic microscopy of tissue sections (1 GHz). Histoacoustics and acoustic staining

The acoustic microstructure of mouse small intestine has been studied with a transmission acoustic microscope working at 1 GHz and the influence of the histologic processing on the microacoustic pattern has been tested. Unstained thin sections provide pictures rich in details and highly contrasted. Gelatin has been used as hydrosoluble embedding medium and has been compared to paraffin. The former embedding procedure retained the viscoelastic properties of the specimen far more and provided the most detailed pictures. Osmiun tetroxide has been used to demonstrate acoustic staining.     

Regulatory dynamics of network architecture and function in tristable genetic circuit of Leishmania: a mathematical biology approach

The emerging field of synthetic biology has led to the design of tailor-made synthetic circuits for several therapeutic applications. Biological networks can be reprogramed by designing synthetic circuits that modulate the expression of target proteins. IPCS (inositol phosphorylceramide synthase) has been an attractive target in the sphingolipid metabolism of the parasite Leishmania. In this study, we have constructed a tristable circuit for the IPCS protein. The circuit has been validated and its long-term behavior has been assessed. The robustness and evolvability of the circuit has been estimated using evolutionary algorithms. The tristable synthetic circuit has been specifically designed to improve the rate of production of phosphatidylcholine: ceramide cholinephosphotransferase 4 (SLS4 protein). Site-specific delivery of the circuit into the parasite-infected macrophages could serve as a possible therapeutic intervention of the infectious disease ‘Leishmaniasis’.     

Transmission acoustic microscopy of tissue sections (1 GHz)

Summary The acoustic microstructure of mouse small intestine has been studied with a transmission acoustic microscope working at 1 GHz and the influence of the histologic processing on the microacoustic pattern has been tested. Unstained thin sections provide pictures rich in details and highly contrasted. Gelatin has been used as hydrosoluble embedding medium and has been compared to paraffin. The former embedding procedure retained the viscoelastic properties of the specimen far more and provided the most detailed pictures. Osmiun tetroxide has been used to demonstrate acoustic staining.