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121.
An adenovirus mRNA which encodes a 14,700-Mr protein that maps to the last open reading frame of region E3 is expressed during infection. 总被引:3,自引:3,他引:0
The E3 regions of adenovirus types 2 and 5, respectively, are known to synthesize proteins of 19,000 Mr (19K) and 11.6K, but information regarding the identity and characterization of other potential E3 proteins encoded by the six remaining open reading frames (ORFs) is lacking. In this study, we show that the last ORF of region E3, which encodes a 14.7K protein, is expressed in adenovirus-infected cells. This information was largely derived from analysis of an E3 deletion mutant (H2dl801) in which an extensive deletion (1,939 base pairs) was found to eliminate all ORFs except for two proteins of 12.5K and 14.7K. The 14.7K protein was translated from RNA isolated from H2dl801-infected cells that had been hybridization selected to E3 DNA; hybridization-selected RNA from wild-type adenovirus type 5-infected cells translated both the 19K and the 14.7K proteins. Moreover, an antiserum directed against a bacterial 14.7K fusion protein (A. E. Tollefson and W. S. M. Wold, J. Virol. 62:33-39, 1988) immunoprecipitated the 14.7K translation product synthesized by wild-type and mutant H2dl801 adenovirus mRNAs. 相似文献
122.
IgA:IgM and IgA:IgA hybrid hybridomas secrete heteropolymeric immunoglobulins that are polyvalent and bispecific 总被引:1,自引:0,他引:1
H B Urnovitz Y Chang M Scott J Fleischman R G Lynch 《Journal of immunology (Baltimore, Md. : 1950)》1988,140(2):558-563
Polyvalent bispecific antibodies were secreted by hybrid hybridoma cells when both parental clones expressed a naturally polymerizing immunoglobulin. Hybrid hybridomas made from IgA lambda 2 anti-trinitrophenyl (TNP) and IgA kappa anti-phosphocholine (PC) parental cells secreted polymeric IgA antibodies that bound both TNP and PC. Some of the TNP binding was dissociated from the PC binding under conditions of mild reduction and alkylation suggesting that the bispecific polymeric IgA contained disulfide-linked parental monomers as well as bispecific hybrid monomers. Hybrid hybridomas constructed from IgA lambda 2 anti-TNP and IgM kappa anti-ox erythrocyte parental cells secreted bispecific, polymeric immunoglobulin that contained mu-, alpha-, kappa-, and lambda 2-chains. The mu and kappa-chains dissociated from the alpha- and lambda 2-chains under conditions of mild reduction and alkylation, indicating that both parental monomers had been incorporated into the same polymeric immunoglobulin to form a heteropolymeric antibody molecule. Heterologous pairing of alpha and mu heavy chains in monomers was not detected. Hybrid hybridomas constructed from IgA lambda 2 and IgG3 lambda 2 or IgA lambda 2 and IgG1 kappa parents co-secreted both parental immunoglobulins, but the antibodies secreted by these clones did not form heteropolymers or exhibit heterologous heavy chain pairing. These findings establish that polyvalent, bispecific, polymeric immunoglobulin molecules can be produced by hybrid hybridomas when both parents express a naturally polymerizing class of heavy chain but not when only one parent does. Hybrid hybridomas that produce heteropolymeric immunoglobulins are sources of high avidity bispecific antibodies that may find a number of basic and practical applications. The hybridoma cells that produce these antibodies may provide useful tools for investigating the in situ determinants of immunoglobulin chain association and the regulation of antibody assembly and secretion. 相似文献
123.
Twenty-two patients with roping injuries to 38 digits, including 19 patients injured while team roping, are discussed. Ten digits in nine patients were successfully revascularized or replanted. Seven digits in three patients failed after initial success. One patient is included in both categories. The failure rate is 41 percent for all 17 digits. Average follow-up is 18 months. The dominant hand was injured in 83 percent of team roping injuries; the thumb is the most commonly injured digit. Average interphalangeal motion for thumb replants is zero; for revascularizations, it is 47 degrees. There was 43 percent return of pinch strength for thumb replants compared to 83 percent return for a single thumb revascularization. The most common mechanism of injury was catching the roping thumb in the "thumb up" position during dallying. There are good motion and pinch strength with thumb revascularizations provided tendons and the interphalangeal joint are intact. Reconstruction of the flexor pollicis longus in the replanted thumb gave poor results. Primary tenodesis or arthrodesis is recommended. 相似文献
124.
Antone L. Brooks Scott W. Jordan Kallol K. Bose Jennifer Smith David C. Allison 《Cell biology and toxicology》1988,4(1):31-40
The cytogenetic and hepatotoxic effects of 2,3,7,8-tetrachlorodibenzo p-dioxin (TCDD) on mouse liver cells were investigated. Male C57BL/6J strain mice, which have TCDD receptors, were given single intraperitoneal injections of 25, 37.5, 75 and 150 g of TCDD/kg body weight or corn oil carrier alone. Two-thirds hepatectomies were carried out at 1 or 7 days after injection and chromosomal aberrations and mitotic indexes of the regenerating hepatocytes were scored 54 hr after hepatectomy. Liver sections from additional intact mice were studied for TCDD-hepatotoxicity at 1, 7 and 30 days after injection. The three high doses of TCDD caused hepatotoxicity with necrosis of liver cells and focal architectural collapse by 30 days after injection. No evidence was obtained of an increase in the frequency of chromosomal structural aberrations at doses that allowed sufficient mitotic activity for cytogenetic evaluation. We conclude that TCDD is not a clastogen for mouse hepatocytes, although high doses cause marked hepatocellular necrosis.Abbreviations CSD
chromosome deletion
- META
metacentric chromosome
- TCDD
2,3,7,8-tetrachlorobenzo-p-dioxin 相似文献
125.
Process intensity of fixed bed glass sphere culture systems is increased considerably by replacing solid glass spheres with open pore glass spheres. This technique demonstrates the possibility of having a system capable of both volumetric and cell density scale up and being suitable for substrate attached and suspension cells. The yields achieved for a number of attached cell lines (approximately 107/ml) demonstrate an increase approaching one order of magnitude over solid glass spheres (approximately 106/ml). Also suspension cells were successfully entrapped in the open pore structure with similar yields. 相似文献
126.
Paul D Griffiths Jillian R Mann Philip J Darbyshire Anne Green 《BMJ (Clinical research ed.)》1988,296(6636):1583-1585
A pilot neonatal screening programme for haemoglobinopathies linked with screening for phenylketonuria and congenital hypothyroidism was reviewed. During 1978 to December 1986 137 000 neonates were tested. There were improvements in the detection rate and accuracy of diagnosis for homozygotes and mixed heterozygotes, mainly associated with the introduction of citrate agarose gel electrophoresis as a follow up procedure on all specimens showing any abnormality on the initial cellulose acetate electrophoresis.We recommend that the programme is continued on a service basis. 相似文献
127.
Predation by naturally occurring predatory arthropods was investigated to explain variations in population numbers of twospotted
spider mite (Tetranychus urticae Koch) between first and second season strawberry crops.
Araneomorph spiders. European harvestman [Phalangium opilio (L.)], Tasmanian lacewing [Micromus tasmaniae (Walker)] and Pacific damsel bug [Nabis kinbergii Reuter] were the only predators found in high numbers. However, spiders and harvestment were more prevalent than lacewings
and nabids.
Laboratory feedings trials indicated spiders build horizontal webs in the plants and prey predominantly on small flying insects
that shelter in the crops. Similar feeding trials cofirmed the palatability of TSSM to spiders and harvestmen.
Immunological testing for proteins of TSSM, aphids, Collembola and leafrollers in the intestines of field collected European
harvestman, spiders, Tasmanian lacewing and Pacific damsel bug confirmed European harvestman includes TSSM in its diet, but
not in large enough quantities to exert a significant regulating pressure on TSSM populations. Lacewings and nabids include
TSSM in their diets but only in very small quantities (2% and 1% respectively). Spiders do not take TSSM unless they drop
or spin down onto the spider webbing.
The immunological testing also showed European harvestman to be a polyphagous and opportunistic feeder. Prey residues were
detected more frequently in harvestmen intestines at times of prey abundance which indicated a seasonality to harvestmen diet.
相似文献
128.
P. Hiscott H. A. Waller I. Grierson M. G. Butler D. Scott 《Cell and tissue research》1992,267(1):185-192
Summary The distribution of fibronectin mRNA and fibronectin in adult human retina and epiretinal membranes was investigated by in situ hybridisation and immunohistochemical techniques. The cells in normal adult retina contained little or no fibronectin mRNA and the retina only showed fibronectin immunoreactivity in retinal vessels. The cells in detached neuroretina did not contain fibronectin message but the vitreoretinal interface of the detached retina exhibited variable fibronectin immunoreactivity. Retinal glia, retinal pigment epithelium and fibroblast-like cells in membranes at the vitreoretinal juncture (epiretinal membranes) showed variable labelling with the fibronectin mRNA probe and all the membranes immunostained for fibronectin. No difference could be detected between membrane cell types in the intensity of labelling with the mRNA probe or for fibronectin immunoreactivity. The results indicate that cells in situ in attached and detached adult human retina do not produce fibronectin. Although fibronectin at the vitreoretinal juncture in retinal detachment is probably partly derived from plasma fibronectin resulting from breakdown of the blood-retinal barrier, ectopic retinal cells produce fibronectin and contribute to the glycoprotein in epiretinal membranes. 相似文献
129.
Michael J. Jenkins James Sneyd Scott Camazine J. D. Murray 《Journal of mathematical biology》1992,30(3):281-306
We present a simplified version of a previously presented model (Camazine et al. (1990)) that generates the characteristic
pattern of honey, pollen and brood which develops on combs in honey bee colonies. We demonstrate that the formation of a band
of pollen surrounding the brood area is dependent on the assumed form of the honey and pollen removal terms, and that a significant
pollen band arises as the parameter controlling the rate of pollen input passes through a bifurcation value. The persistence
of the pollen band after a temporary increase in pollen input can be predicted from the model. We also determine conditions
on the parameters which ensure the accumulation of honey in the periphery and demonstrate that, although there is an important
qualitative difference between the simplified and complete models, an analysis of the simplified version helps us understand
many biological aspects of the more complex complete model.
Corresponding author 相似文献
130.
Dr. R. Scott Pore 《Current microbiology》1992,24(3):171-177
The flow cytofluorometric susceptibility test (FCST) was incorporated into two in vitro synergy assays of amphotericin B-drug combinations. The FCST checkerboard assay and the FCST concentration-effect assay were developed to detect subtle modulation of amphotericin B fungicidal effects onCandida albicans andCryptococcus neoformans. Amphotericin B × cyclosporine A was a synergistic fungicidal combination against bothC. albicans andC. neoformans. Amphotericin B×gentamicin and amphotericin B×ketoconazole were synergistic combinations againstC. neoformans. In all cases tested, the synergy was effective when 0.50–0.62 g amphotericin B/ml was used with>-0.50 g of the other drug/ml. The fungicidal effect of 1.00 g amphotericin B/ml overwhelmed the synergistic effects. A number of other drug combinations were additive, autonomous, or antagonistic. 相似文献