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31.
T cytotoxic cells generated to syngeneic SV40 virus transformants lyse only SV40 target cells that are syngeneic at the H-2 locus. In contrast, SV40-specific tumor transplantation immunity shows no requirements for syngeneic H-2. Inoculation of allogeneic or even xenogeneic transformants will confer immunity to a challenge of syngeneic SV40 tumor cells. The experiments described here represent an attempt to reconcile these apparently conflicting observations. In our hands, generation of SV40-specific T cytotoxic cells in vitro requires both in vivo priming and secondary in vitro sensitization. We have found that priming for a secondary syngeneic-restricted response requires only that the cell employed be SV40 transformed. That is, priming may be accomplished with syngeneic, allogeneic, or xenogeneic SV40 transformants. Thus, the apparent lack of H-2 restriction in vivo immunity does not eliminate a role for the H-2-restricted cytotoxic T cell in tumor transplantation immunity.  相似文献   
32.
We have used the human globin locus control region (LCR) to assemble an expression system capable of high-level, integration position-independent expression of heterologous genes and cDNAs in murine erythroleukaemia (MEL) cells. The cDNAs are inserted between the human beta-globin promoter and the second intron of the human beta-globin gene, and this expression cassette is then placed downstream of the LCR and transfected into MEL cells. The cDNAs are expressed at levels similar to those of the murine beta-globin in the induced MEL cells. Heterologous genomic sequences can also be expressed at similar levels when linked to to the LCR and beta-globin promoter. In addition we demonstrate that, after induction of differentiation, MEL cells are capable of secreting heterologous proteins over a prolonged time period, making this system suitable for use in continuous production systems such as hollow fibre bioreactors. The utility of the LCR/MEL cell system is demonstrated by the expression of growth hormone at high levels (greater than 100 mg/l) 7 days after induction. Since the expression levels seen do not depend upon gene amplification and are independent of the integration position of the expression cassette, it is possible to obtain clones with stable high-level expression within 3-4 weeks after transfection.  相似文献   
33.
It may be difficult to differentiate between cells of parathyroid and thyroid origin in ultrasound-guided fine needle aspirations of the neck region, even in patients with a clinical history of hyperparathyroidism. A parathyroid hormone antibody was used in an immunohistochemical system to confirm a parathyroid origin in fine needle aspirate smears from nine patients with hyperparathyroidism. Immunoperoxidase positivity for parathyroid hormone confirmed a parathyroid origin in six of nine cases and was strongly suggestive, although equivocal, in the remaining three cases. Technical problems included nonuniform staining and background staining.  相似文献   
34.
Plasma catecholamine levels during water immersion in man   总被引:1,自引:0,他引:1  
In ten normal subjects thermoneutral neck-out water immersion produced a highly significant natriuresis and diuresis mediated via an induced central hypervolaemia. During immersion suppression of plasma noradrenaline and adrenaline was observed but no change occurred in plasma dopamine levels. No correlation was found between the suppression of noradrenaline and the diuresis and natriuresis. The reduction in plasma noradrenaline observed may reflect a widespread diminution of sympatho-adrenal activity during water immersion. This reduction could be a consequence of the cardiovascular changes of immersion and may not be directly involved in the mechanism of the renal response.  相似文献   
35.
An antiserum raised in a goat to a uteroglobin-like protein isolated from uterine fluid of oestrous rabbits was used in an immune fluorescence test to localize an antigen present in the reproductive tract of oestrous and pseudopregnant rabbits and mammary gland tissue. The antigen was also present in the vas deferens and seminal vesicle, but not in testis. Non-reproductive tissues, such as lung, small intestine, bladder and thyroid showed specific fluorescent staining which was eliminated or significantly reduced by absorption of the antiserum with a purified uteroglobin preparation.  相似文献   
36.
The use of a fascial flap in ear reconstruction.   总被引:2,自引:0,他引:2  
We describe the use of a fascial flap for covering the framework in ear reconstruction. When covered in turn with a skin graft, this fascial flap provides an abundant amount of a thin, tough, vascular, hairless cover of good quality in all cases except those where injuries in the auricular area have been deep enough to damage this fascia. This method of ear reconstruction is particularly useful in secondary ear reconstructions useful in secondary ear reconstructions and in reconstruction after traumatic losses. The procedure described can often be performed in one stage, requiring two to 4 hours, with minimal complications.  相似文献   
37.
Cell-mediated immunity to SV40-transformed C3H and C3H-SW cell lines was measured by using both 51Cr and 125IUdR release assays. Killing by cytotoxic cells generated on in vitro sensitization of immune spleen cells with syngeneic SV40 cells by either assay is specific for syngeneic SV40 transformants. Cytolysis mediated by in vitro sensitized cells is ablated by treatment of the effector cells with anti-theta serum and complement. Intraperitoneal immunization with syngeneic SV40 cells yields two distinct killer-cell populations in the peritoneal exudate when assayed by 125IUdR release. The first, nylon wool nonadherent and sensitive to anti-theta and complement, is indistinguishable from the killers generated in vitro. The second population, present in larger numbers and more efficient on a per-cell basis in killing of SV40 targets than the first, is nylon adherent and is not removed by treatment with anti-theta and complement. This second population will kill any SV40 transformed target, whether syngeneic or allogeneic. The possible roles of T cell and non-T cell effectors in rejection of syngeneic SV40 tumors are discussed.  相似文献   
38.
39.
Subedi  K. D.  Gregory  P. J.  Gooding  M. J. 《Plant and Soil》1999,214(1-2):141-152
Two pot experiments at the Plant Environment Laboratory (PEL), Reading, UK investigated sterility, boron (B) accumulation and B partitioning of wheat cultivars grown with limited B in the growing medium. The first experiment evaluated nine cultivars of spring wheat with diverse field responses to low available soil B, supplied with or without 20 μM B. A second experiment examined the response of a susceptible (SW-41) and a tolerant (Fang-60) cultivar to B-deficiency. These cultivars were supplied with either 20 μM B from sowing to flag leaf emergence and no added B thereafter, or 20 μM B from sowing to maturity. When B was not supplied in the nutrient solution, the number of grains ranged from 4 per ear (cv. BL-1135) to 32 per ear (cv. BL-1249) and sterility of competent florets ranged from 39% to 93%. Boron concentration in the flag leaf at anthesis did not differ greatly when the growing medium contained limited B, but differences between cultivars were evident when B was unlimited. Tolerance of B-deficiency was not related to the B concentration in the flag leaf. Some cultivars produced viable pollen and set grains while others failed to do so at similar B concentrations in the flag leaf. The two contrasting cultivars did not differ much in their pattern of B partitioning when B supply was restricted from flag leaf emergence onwards. Similarly, little evidence was found that the tolerant cultivars translocated B from their leaves, roots or stems when the supply in the growing medium was restricted. The proportion of total B partitioned in different organs was the same irrespective of B supply and cultivar. On average, leaves contained 68% of the total B content in the whole plant compared to 16% in the roots, 10% in the ears and only 6% in the stems. Tolerant or susceptible cultivars of wheat could not be distinguished based on the B concentration and B content of the flag leaf. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
40.
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