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41.
42.
Salmon calcitonin (sCT) is an example of one of the many bioactive peptides that require amidation of the carboxy terminus for full potency. We describe a method for the production of amidated sCT in the mammary gland of transgenic rabbits. Expression of a fusion protein comprising human alpha lactalbumin joined by an enterokinase cleavable linker to sCT was directed to the mammary gland under the control of the ovine beta lactoglobulin promoter. C-terminal amidation in vivo was achieved by extending the sCT by a single glycine residue that provides a substrate for endogenous amidating activity in the mammary gland. Full characterization of the released sCT demonstrated it to be equivalent to synthetic standard in terms of structure, purity, and potency. 相似文献
43.
T Self M Mahony J Fleming J Walsh SD Brown KP Steel 《Canadian Metallurgical Quarterly》1998,125(4):557-566
The mouse shaker-1 locus, Myo7a, encodes myosin VIIA and mutations in the orthologous gene in humans cause Usher syndrome type 1B or non-syndromic deafness. Myo7a is expressed very early in sensory hair cell development in the inner ear. We describe the effects of three mutations on cochlear hair cell development and function. In the Myo7a816SB and Myo7a6J mutants, stereocilia grow and form rows of graded heights as normal, but the bundles become progressively more disorganised. Most of these mutants show no gross electrophysiological responses, but some did show evidence of hair cell depolarisation despite the disorganisation of their bundles. In contrast, the original shaker-1 mutants, Myo7ash1, had normal early development of stereocilia bundles, but still showed abnormal cochlear responses. These findings suggest that myosin VIIA is required for normal stereocilia bundle organisation and has a role in the function of cochlear hair cells. 相似文献
44.
DV Serreze SA Fleming HD Chapman SD Richard EH Leiter RM Tisch 《Canadian Metallurgical Quarterly》1998,161(8):3912-3918
Nonobese diabetic (NOD) mice genetically deficient in B lymphocytes (NODJg mu(null)) are resistant to T cell-mediated autoimmune insulin-dependent diabetes mellitus (IDDM). Ig infusions from diabetic NOD donors did not abrogate IDDM resistance in NODJg mu(null) mice. However, T cell responses to the candidate pancreatic beta cell autoantigen glutamic acid decarboxylase (GAD), but not the control Ag keyhole limpet hemocyanin, were eliminated in NODJg mu(null) mice. To initially test whether they contribute to IDDM as APC, NOD B lymphocytes were transferred into NODJg mu(null) recipients. B lymphocytes transferred into unmanipulated NODJg mu(null) recipients were rejected by MHC class I-restricted T cells. Stable T and B lymphocyte repopulation was achieved in irradiated NODJg mu(null) mice reconstituted with syngeneic bone marrow admixed with NOD B lymphocytes. IDDM susceptibility was restored in NODJg mu(null) mice reconstituted with syngeneic marrow plus B lymphocytes, but not with syngeneic marrow only. T cell responses to GAD were restored only in NODJg mu(null) mice reconstituted with syngeneic marrow plus B lymphocytes. Hence, B lymphocytes appear to contribute to IDDM in NOD mice as APC with a preferential ability to present certain beta cell Ags such as GAD to autoreactive T cells. 相似文献
45.
Gerald J. Fleming 《应用聚合物科学杂志》1969,13(5):989-997
The thermal properties of polymers derived from resorcinol diglycidyl ether cured with several bicyclo Diels-Alder anhydride adducts have been investigated. Increased char yields and decreased rates of weight loss were observed for these systems as compared to polymers cured by Diels–Alder adducts from acyclic dienes. This is explained on the basis of a reverse Diels-Alder reaction which these bicyclo adducts undergo at lower temperatures than do adducts from acyclic dienes. 相似文献
46.
The photonitration of isobutane (i-C4 H10 ) has been investigated in the 458-515 nm region with an argon-ion laser as the radiation source, t-nitrobutane (t-C4 H9 NO2 ) was the major product. Its rate of production was linear with laser intensity and increased with increasing photon energy. Computer modeling of possible reaction steps indicated that the reaction is initiated by the direct abstraction of hydrogen from i-C4 H10 by electronically excited NO2 . 相似文献
47.
Probabilistic safety analyses of the High Temperature Gas Cooled Reactor are being performed by the General Atomic Company. The project is sponsored by the Energy Research and Development Administration and is known as Accident Initiation and Progression Analysis. Probabilistic methods are used to estimate the probability of failure of the HTGR cooling systems. 相似文献
48.
Isolation and characterization of a Lactobacillus plantarum bacteriophage,phiJL-1, from a cucumber fermentation 总被引:2,自引:0,他引:2
Lu Z Breidt F Fleming HP Altermann E Klaenhammer TR 《International journal of food microbiology》2003,84(2):225-235
A virulent Lactobacillus plantarum bacteriophage, PhiJL-1, was isolated from a commercial cucumber fermentation. The phage was specific for two related strains of L. plantarum, BI7 and its mutant (deficient in malolactate fermenting ability) MU45, which have been evaluated as starter cultures for controlled cucumber fermentation and as biocontrol microorganisms for minimally processed vegetable products. The phage genome of PhiJL-1 was sequenced to reveal a linear, double-stranded DNA (36.7 kbp). Sodium dodecyl sulfate-polyacryamide gel electrophoresis (SDS-PAGE) profiles indicated that PhiJL-1 contains six structural proteins (28, 34, 45, 50, 61, and 76 kDa). Electron microscopy revealed that the phage has an isometric head (59 nm in diameter), a long non-contractile tail (182 nm in length and 11 nm in width), and a complex base plate. The phage belongs to the Bradley group B1 or Siphoviridae family. One-step growth kinetics of the phage showed that the latent period was 35 min, the rise period was 40 min, and the average burst size was 22 phage particles/infected cell. Phage particles (90%) adsorbed to the host cells 20 min after infection. Calcium supplementation (up to 30 mM CaCl(2)) in MRS media did not affect the first cycle of phage adsorption, but promoted rapid phage propagation and cell lysis in the infection cycle subsequent to adsorption. The D values of PhiJL-1 at pH 6.5 were estimated to be 2.7 min at 70 degrees C and 0.2 min at 80 degrees C by a thermal inactivation experiment. Knowledge of the properties of L. plantarum bacteriophage PhiJL-1 may be important for the development of controlled vegetable fermentations. 相似文献
49.
Comparison of physician based reporting of tobacco attributable deaths and computer derived estimates of smoking attributable deaths, Oregon, 1989 to 1996
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BACKGROUND: Tobacco use prevention programmes need accurate information about smoking related mortality. Beginning in 1989, Oregon began asking physicians to report on death certificates whether tobacco use contributed to the death. OBJECTIVE: To determine the long term comparability of this method of estimating tobacco attributable mortality to estimates of smoking attributable mortality derived from a computer model. DESIGN: For the period 1989 to 1996, we compared mortality resulting from tobacco use reported by Oregon physicians to estimates of smoking attributable deaths (SADs) derived by "Smoking attributable mortality, morbidity and economic costs" software version 3.0 (SAMMEC 3.0), a widely used software program that estimates SADs on the basis of smoking prevalence and relative risks of specific diseases among current and former smokers. MAIN OUTCOME MEASURES: Numbers of deaths, age, sex, and category of disease. RESULTS: Of 212, 448 Oregon deaths during 1989-1996, SAMMEC 3.0 estimated that 42, 778 (20.1%) were attributable to cigarette smoking. For the same 27 diagnoses, physicians reported that tobacco contributed to 42, 839 (20.2%) deaths-a cumulative difference of only 61 deaths over the eight year period. The age and sex distributions of tobacco and smoking attributable deaths reported by the two systems were also similar. By category of disease, the ratio of SAMMEC 3.0 estimates to physician reported deaths was 1.11 for neoplasms, 0.88 for heart disease, and 1.04 for respiratory disease. CONCLUSIONS: Physician reporting provides comparable estimates of smoking attributable mortality and can be a valuable source of data for communicating the risks of tobacco use to the public. 相似文献
50.