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991.
Summary ExposingBacillus
subtilis cultures to high concentrations of alkali cations, especially K+, allows efficient transformation by plasmids. The method allows transformation with unfractionated plasmid DNA, monomeric plasmid DNA as well as linear plasmid DNA.B.
subtilis strains, not amenable to natural transformation, were also transformed by the present method. 相似文献
992.
993.
994.
S. Fujimori I. Akaoka K. Sakamoto H. Yamanaka K. Nishioka N. Kamatani 《Human genetics》1985,71(2):171-176
Summary 2,8-Dihydroxyadenine urolithiasis associated with partial deficiencies of adenine phosphoribosyltransferase (APRT) has been found only among Japanese families. All Caucasian patients with the same lithiasis are completely deficient in this enzyme. Partially purified APRT from one of the Japanese families with the lithiasis associated with a partial deficiency of APRT had a reduced affinity for 5-phosphoribosyl-1-pyrophosphate (PRPP). In the present investigations, we have shown that this characteristic is common in mutant enzymes from all the four separate Japanese urolithiasis families associated with partial APRT deficiencies so far tested. The mutant enzymes also had several other characteristics in common including increased resistance to heat in the absence of PRPP and reduced sensitivity to the stabilizing effect of PRPP. These data suggest that these families have a common mutant allele (APRT
*
J) at the APRT gene locus. 相似文献
995.
Understanding the molecular architecture of the flagellum is crucial to elucidate the bending mechanism produced by this complex organelle. The current known structure of the flagellum has not yet been fully correlated with the complex composition and localization of flagellar components. Using cryoelectron tomography and subtomogram averaging while distinguishing each one of the nine outer doublet microtubules, we systematically collected and reconstructed the three-dimensional structures in different regions of the Chlamydomonas flagellum. We visualized the radial and longitudinal differences in the flagellum. One doublet showed a distinct structure, whereas the other eight were similar but not identical to each other. In the proximal region, some dyneins were missing or replaced by minor dyneins, and outer-inner arm dynein links were variable among different microtubule doublets. These findings shed light on the intricate organization of Chlamydomonas flagella, provide clues to the mechanism that produces asymmetric flagellar beating, and pose a new challenge for the functional study of the flagella. 相似文献
996.
Kawasaki T Nakamura K Jeschke MG Kogiso M Kobayashi M Herndon DN Suzuki F 《Immunology and cell biology》2012,90(8):796-801
Immunosuppressive neutrophils (PMN-II) appearing in association with burn injury have a role on the increased susceptibility of burn patients to various infections. In the present study, the role of PMN-II on the production of human β-defensins (HBDs), important molecules on host antimicrobial innate immunities, by human keratinocytes was studied. Normal human epidermal keratinocytes (NHEKs) were cultured with neutrophils (PMNs) isolated from burn patients or healthy volunteers in dual-chamber transwells. Culture fluids harvested 24?h after cultivation were assayed for HBDs using enzyme-linked immunosorbent assay. Also, these culture fluids were assayed for their antimicrobial activities by a standard colony-counting method using Pseudomonas aeruginosa. In the results, PMNs isolated from peripheral blood of burn patients were confirmed as PMN-II, because these cells produced CC-chemokine ligand 2 (CCL2), but not interleukin (IL)-12 and CC-chemokine ligand 3 (CCL3). Culture fluids of NHEK transwell-cultured with healthy PMNs exhibited strong killing activities against P. aeruginosa (96% inhibition), however, the growth of bacteria was not dramatically inhibited by the culture fluids of NHEK transwell-cultured with burn-patient PMNs (36% inhibition). IL-12 and CCL3 containing culture fluids of healthy PMNs stimulated with the bacterial antigen or rCCL3 and rIL-12 enhanced the production of HBD2 and HBD3 by NHEK, whereas CCL2 containing culture fluids of burn-patient PMN stimulated with the antigen or rCCL2 inhibited the HBD production by NHEK. These results indicate that PMN-II appearing in association with burn injury contribute to the decreased production of HBDs in thermally injured patients. 相似文献
997.
998.
Cancer vaccines: single-epitope anti-idiotype vaccine versus multiple-epitope antigen vaccine 总被引:5,自引:0,他引:5
Maruyama H Zaloudik J Li W Sperlagh M Koido T Somasundaram R Scheck S Prewett M Herlyn D 《Cancer immunology, immunotherapy : CII》2000,49(3):123-132
In this study, we compared the immunogenicity and tumor-protective activity of anti-idiotypic antibodies mimicking a single
tumor-associated epitope and tumor-associated antigen expressing multiple potentially immunogenic epitopes. We focused our
study on the colorectal-carcinoma(CRC)-associated antigen GA733 (also known as CO17-1A/KS1-4/KSA/EpCAM). Monoclonal anti-idiotypic
antibody (Ab2) BR3E4 was produced against murine anti-CRC mAb CO17-1A (Ab1) in rats. Full-length native GA733 protein was
isolated from human tumor cells, and the extracellular domain protein (GA733-2E) was isolated from supernatants of recombinant
baculovirus-infected insect cells by immunoafffinity chromatography. The immunomodulatory activity of the Ab2 was compared
with that of the antigen, both in rabbits and in mice. Mice, like humans but not rabbits, express a GA733 antigen homologue
on some of their normal tissues. Thus, these in vivo models allow the comparison of the immunogenicity of Ab2 and antigen
in the presence (mice) and absence (rabbits) of normal tissue expression and immunological tolerance of the GA733 antigen
homologue. In rabbits, aluminum-hydroxide(alum)-precipitated native GA733 antigen was superior to alum-precipitated Ab2 in
inducing specific humoral immunity. In mice, alum-precipitated recombinant GA733-2E antigen, but not alum-precipitated Ab2,
induced specific humoral immunity. However, when the Ab2 was administered to mice in Freund's complete adjuvant, specific
humoral immune responses were elicited. Ab2 in complete Freund's adjuvant and GA733-2E in alum were compared for their capacity
to induce antigen-specific cellular immunity in mice. Whereas lymphoproliferative responses were obtained with the recombinant
antigen only, delayed-type hypersensitivity responses were obtained with both recombinant antigen and Ab2, although these
responses were lower than after antigen immunization. The recombinant antigen in alum did not protect mice against challenge
with antigen-positive syngeneic murine CRC cells. Similar studies with Ab2 BR3E4 mimicking the CO17-1A epitope were not possible
because the tumor cells do not express this epitope after transfection with the human GA733-2 cDNA. However, similar studies
with Ab2 mimicking the epitope defined by mAb GA733, which is expressed by the transfected tumor cells, indicated a lack of
tumor-protective activity of this Ab2. In contrast, the full-length antigen expressed by recombinant adenovirus inhibited
the growth of established tumors in mice. In conclusion, soluble antigen is a more potent modulator of humoral and cellular
immune responses than Ab2, both administered in adjuvant. However, for induction of protective immunity, the immunogenicity
of the antigen must be further enhanced, e.g., by expression of the antigen in a viral vector.
Received: 27 December 1999 / Accepted: 27 January 2000 相似文献
999.
Hiroaki Egashira Akira Kuwashima Hiromi Ishiguro Kazuhiro Fukushima Takashi Kaya Shigeru Imanishi 《Acta Physiologiae Plantarum》2000,22(3):324-326
Tomato gray mold (Botrytis cinerea Pers.) is a common disease worldwide, and often causes serious production loss by infecting leaves, stems, flowers and fruits.
Presently, no resistant cultivars are available. To find new breeding materials for gray mold resistance, assessment for resistance
of the leaflet and stem in six tomato cultivars, 44 wild tomato accessions and a Solanum lycopersicoides accession was performed. Although no correlation was observed (r=−0.127ns) between resistance of the leaflet and the stem, L. peruvianum LA2745, L. hirsutum LA2314 and L. pimpinellifolium LA1246 showed high resistance both in the leaflet and in the stem. Particularly, in the leaves of LA2745, no lesions were
observed even more than two weeks after the inoculation with conidia, and F1s between a cultivated tomato and LA2745 also
showed high resistance as observed in LA2745. From these results, LA2745 is thought to be a promising material for breeding
gray-mold resistant cultivars. 相似文献
1000.
Aggregation of Lepidostomatidae in small mesh size litter-bags: implication to the leaf litter decomposition process 总被引:1,自引:0,他引:1
Aung Nanda Takashi Asaeda Takeshi Fujino Kian Siong Takashi Nakajima 《Wetlands Ecology and Management》2009,17(4):417-421
Invertebrate colonization during leaf litter decomposition was studied at the 2nd order of Yanase River, Iruma city, Saitama,
Japan from November 13, 2002 to May 20, 2003. Two different mesh sizes (1 and 5 mm) of litter-bags were used to evaluate the
decomposition of leaf litter of Sakura (Prunus lannesiana), bags were placed equally in riffle (water flow velocity: 0.2–0.6 m s−1) and pool (water flow velocity: 0.04–0.06 m s−1). Mass loss and invertebrates in the litter-bags were monitored at interval between 1 and 3 weeks, and the invertebrates
were classified based on their functional feeding group. Among the invertebrates found inside the litter-bags, the case-bearing
shredder Lepidostomatidae was the most dominant invertebrates and they were the early colonizer that appeared about 3 months
after the litter-bags immersion. In absence or low number of leaf-shredders, the decomposition rates in 1 and 5 mm litter
mesh bags followed the exponential (or first-order) decay kinetic (R
2: 0.72–0.92). However, the presence of a large number of leaf-shredders in 1 mm litter-bags caused an acceleration of decomposition
process; that even resulted faster mass loss than the loss from the 5 mm mesh bags placed in riffle area (0.030 day−1 vs. 0.011 day−1). Our results shows the importance of using different mesh sizes of litter-bags in decomposition study, which is applicable
to the experiment in lotic or lentic ecosystem. Using smaller mesh size of litter-bags can provide information on how significant
the effect of detritus feeders on the decomposition process, while the bigger mesh size can represent better the natural decomposition
process when a large number detritus feeders is present in the smaller mesh size of litter-bags. 相似文献