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1.
Techniques are described for capturing and marking redtail monkeys (Cercopithecus ascanius). An air-powered darting rifle and syringe darts loaded with a Ketamine-Rompun mixture were used for capture. Ketamine was used for maintaining anesthesia. Monkeys were darted 48 times and captured 27 times. In 24 of the 27 captures, the monkeys were released unharmed. Adult males were marked with radiotransmitters attached to collars of nylon webbing. Females received nylon webbing collars with colorcoded plastic washers for identification.  相似文献   
2.
UV-visible and 13C NMR measurements described in the literature and our 31P NMR measurements support the following mechanism of proton transfer reactions in aqueous solutions of pyridoxamine phosphate: Only the tautomeric equilibrium between neutral form, A N, and zwitterion, A Z, which is analogous to the tautomeric equilibrium of 3-hydroxypyridine in aqueous solution, is important, and that equilibrium does not change upon the dissociation of the second phosphate proton. With these simplifying assumption, we have simulated the relaxation spectrum of the proton transfer reactions of pyridoxamine phosphate in water using parameters from analogous reactions and compared it with our ultrasound and temperature jump measurements. We have found that the relaxation process measured by the temperature jump experiment is mainly caused by the overall reaction A N=A Z (or A N - =A Z - ) and the ultrasound absorption at the isoelectric point between pK2 and pK3 is mainly caused by the overall reaction .  相似文献   
3.
The enzymatic production of tryptophan from indole and serine was investigated in a micellar solution of the surfactant Brij 56 in cyclohexane. An anion exchanger was employed to facilitate the transfer of tryptophan and serine between the water pool of the reverse micelle and the bulk organic phase. The influence of potassium ion, water content, pH, and co-surfactant on enzyme activity is reported. Kinetic studies indicate that the enzyme is not inhibited by indole in the micellar system and that the enzyme is more stable in reverse micelles than in bulk water. The design of a continuous reverse micelle reactor, which accommodates both product recovery and enzyme reactivation, is discussed.  相似文献   
4.
We report here the isolation of a monoclonal antibody, J17, that reacts with a conserved vertebrate protein antigen that is present in the spindle apparatus during mitosis but found within the nucleus during interphase. Immunofluorescence microscopy demonstrates that the J17 antigen is found in numerous punctate regions that are distinct from nucleoli. Furthermore, this antigen is not directly associated with kinetochores, the nuclear envelope, or with metaphase chromosomes. — Antibody J17 immunoprecipitates a single polypeptide of very high molecular weight (over 250000) from K562 human erythroleukemia cells pulse-labeled with 14C-leucine. This polypeptide is converted quantitatively to a stable 220-kilodalton product within one cellular generation. We discuss the possible relevance of this processing event for transport into the nucleus. The J17 antigen is synthesized throughout the cell cycle in Chinese hamster ovary cells.  相似文献   
5.
Reovirus is a double-stranded RNA-virus which induces myocarditis in newborn mice. Due to the large diameter of the viral particles (70-75 nm) it can be detected by electron microscopy. Subcutaneous inoculation of 0.05 ml reovirus type 3 (TCID50-titer: 10(8.5)/ml) into newborn NMRI-mice (12-18 h after birth) caused a grey-yellow mottling on the ventricular surface first seen on the 5th day after birth. At the same time muscle fiber necrosis was observed which increased with time. Electron microscopic investigations of the diseased heart muscle disclosed a marked interstitial oedema, swelling of the tubular system and sarcoplasmic reticulum, and degenerative changes in the mitochondria of individual myocardiocytes as early as the 2nd post-inoculation day. Simultaneously, an enlarged Golgi-apparatus and an increasing number of lysosomes, partially exhibiting acid phosphatase activity, was detected in the perinuclear region of ventricular myocardiocytes. On the 5th day after infection, viruses were detected either within single membrane vesicles, dispersed in cytoplasm or as aggregated clusters in the perinuclear region. These in vivo electron microscopic findings correspond with observations of virus propagation in cell-culture systems.  相似文献   
6.
Several herpesviruses, including cytomegalovirus, induce receptors for the Fc domain of murine immunoglobulin G (IgG) molecules. Viral genes coding for these receptors have been characterized only for alphaherpesviruses. In this report, we describe a new approach that led to the identification of an Fc receptor (FcR) of murine cytomegalovirus (MCMV). The Fc fragment of IgG precipitated glycoproteins (gp) of 86 to 88 and 105 kDa from MCMV-infected cells. Deglycosylation by endoglycosidase F resulted in a protein with a molecular mass of 64 kDa. Injection of complete MCMV DNA or of DNA fragments, and the subsequent testing of cytoplasmic binding of IgG by immunofluorescence microscopy, was used to search for the coding region in the MCMV genome. The gene was located in the HindIII J fragment, map units 0.838 to 0.846, where an open reading frame of 1,707 nucleotides predicts a gp of 569 amino acids with a calculated molecular mass of 65 kDa. The sequence of this gp is related to those of the gE proteins of herpes simplex virus type 1 and varicella-zoster virus. The defined length of the mRNA, 1,838 nucleotides, was in agreement with that of a 1.9-kb RNA expressed throughout the replication cycle, starting at the early stages of infection. Expression of the gene fcr1 by recombinant vaccinia virus resulted in the synthesis of gp86/88 and gp105, each with FcR properties, and the correct identification of the gene encoding the FcR was confirmed by the DNA injection method.  相似文献   
7.
Dilution culture, a method for growing the typical small bacteria from natural aquatic assemblages, has been developed. Each of 11 experimental trials of the technique was successful. Populations are measured, diluted to a small and known number of cells, inoculated into unamended sterilized seawater, and examined three times for the presence of 104 or more cells per ml over a 9-week interval. Mean viability for assemblage members is obtained from the frequency of growth, and many of the cultures produced are pure. Statistical formulations for determining viability and the frequency of pure culture production are derived. Formulations for associated errors are derived as well. Computer simulations of experiments agreed with computed values within the expected error, which verified the formulations. These led to strategies for optimizing viability determinations and pure culture production. Viabilities were usually between 2 and 60% and decreased with >5 mg of amino acids per liter as carbon. In view of difficulties in growing marine oligobacteria, these high values are noteworthy. Significant differences in population characteristics during growth, observed by high-resolution flow cytometry, suggested substantial population diversity. Growth of total populations as well as of cytometry-resolved subpopulations sometimes were truncated at levels of near 104 cells per ml, showing that viable cells could escape detection. Viability is therefore defined as the ability to grow to that population; true viabilities could be even higher. Doubling times, based on whole populations as well as individual subpopulations, were in the 1-day to 1-week range. Data were examined for changes in viability with dilution suggesting cell-cell interactions, but none could be confirmed. The frequency of pure culture production can be adjusted by inoculum size if the viability is known. These apparently pure cultures produced retained the size and apparent DNA-content characteristic of the bulk of the organisms in the parent seawater. Three cultures are now available, two of which have been carried for 3 years. The method is thus seen as a useful step for improving our understanding of typical aquatic organisms.  相似文献   
8.
A novel method for insertion/deletion mutagenesis in meningococci was devised. This consisted of ligating a digest of total chromosomal DNA to a 1.1 kb restriction fragment containing an erythromycin-resistance marker ( ermC ), and subsequent transformation of the ligation mixture into the homologous meningococcal strain H44/76. Southern blotting of a number of the resulting erythromycin-resistant transformants demonstrated that all carried the ermC gene inserted at different positions in the chromosome. Mutants with a specific phenotype were identified by screening with the anti-lipopolysaccharide (LPS) monoclonal antibody MN4A8B2, which is specific for immunotype L3. In this way, two independent L3-negative mutant strains were isolated. In transformation experiments with chromosomal DNA from these mutants, erythromycin-resistance and lack of MN4A8B2 reactivity were always linked, showing that the insertion/deletion was in a locus involved in LPS biosynthesis. On SDS–PAGE, the mutant LPS displayed an electrophoretic mobility intermediate between that produced by the previously isolated galE and rfaF mutant strains. Chemical analysis of the mutant LPS revealed that the structure was probably lipid A–(KDO)2–(Hep)2. Chromosomal DNA flanking the ermC insertion in these two mutant strains was cloned, and used as probe for the isolation of the corresponding region of the wild-type strain. From hybridization and polymerase chain reaction (PCR) analysis, it could be concluded that both mutations map to the same locus. The affected gene probably encodes the glycosyltransferase necessary for adding N -acetylglucosamine to heptose.  相似文献   
9.
The effect of ultraviolet light on the microsporidian Octosporea muscaedomesticae in relation to infection in the adult black blowfly, Phormia regina, was investigated. A 30-Watt germicidal lamp, 253.7-nm wavelength, was used as source of uv light in five investigations. In addition, sunlight served as a uv source in two studies. Viable naked dried spores exposed to the uv lamp at a distance of 10 cm were killed after 15 min. Viable naked spores in an aqueous suspension were killed after 30 min of exposure to the uv lamp and after 3 hr of exposure to bright sunlight, respectively. Daily 30-min uv lamp exposures on living hosts harboring all life phases of the parasite did not interfere with the ensuing infection in the blowfly's midgut and the pathogen's developmental cycle. Spores harvested from uv-treated infected hosts were found to be as infective as spores retrieved from hosts not treated with uv. Spores contained in dried fecal droplets and exposed up to 3 hr to the uv lamp, or 12 hr to bright sunlight, respectively, remained infective. Addition of uric acid to a preparation of naked spores prior to 15- and 30-min uv irradiations yielded 100% infection in both host groups. A uv-protective function is ascribed to components provided by the host's tissues and feces.  相似文献   
10.
The continuous addition of toluene as a solute of treated ballast water from oil tankers into a well-defined estuary facilitated the study of the dynamics of dissolved hydrocarbon metabolism in seawater. Most rates of toluene oxidation were in the range of 1 to 30 pg/liter per h at 0.5 μg of toluene per liter. Near the ballast water injection point, a layer of warm ballast water, rich in bacteria, that was trapped below the less-dense fresh surface water was located. Toluene residence times were approximately 2 weeks in this layer, 2 years elsewhere in Port Valdez, and 2 decades in the surface water of a more oceanic receiving estuary adjacent. Mixing was adequate for a steady-state treatment which showed that 98% of the toluene was flushed from Port Valdez before metabolism and gave a steady-state concentration of 0.18 μg/liter. Total bacterial biomass from direct counts and organism size data was usually near 0.1 mg/liter, but ranged up to 0.8 mg/liter in the bacteria-rich layer. The origin of bacteria in this layer was traced to growth in oil tanker ballast during shipments. The biomass of toluene oxidizers in water samples was estimated from the average affinity of pure-culture isolates for toluene (28 liters per g of cells per h) and observed toluene oxidation kinetics. Values ranged from nearly all of the total bacterial biomass within the bacteria-rich layer down to 0.2% at points far removed. Because the population of toluene oxidizers was large with respect to the amount of toluene consumed and because water from a nearby nonpolluted estuary was equally active in facilitating toluene metabolism, we searched for an additional hydrocarbon source. It was found that terpenes could be washed from spruce trees by simulated rainfall, which suggested that riparian conifers provide an additional and significant hydrocarbon source to seawater.  相似文献   
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