摘要:

SummaryLiving attenuated vaccines offer the promise of providing more effective immunity against influenza than inactivated vaccines. However, the development of such vaccines presents unique problems, because influenza A viruses undergo frequent antigenic change and are highly infectious. Ideally, a living vaccine should produce substantial immunity to the disease from a single dose administered in the form of nose drops. The vaccine should be suitably attenuated, with attenuation being determined byin vitromarkers which allow the ready detection of revertants to virulence. The only practical approach is to use a thoroughly accredited master strain which can be recombined with a contemporary virulent strain to produce an attenuated recombinant having the surface antigens of the contemporary strain. Of the master strains currently being developed, temperature‐sensitive (ts) and cold‐adapted (ca) mutants appear to have the greatest promise.

ISSN:0004-945X    

DOI:10.1038/icb.1980.44

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryStreptozotocin‐induced diabetes is temporarily reversed following the allo‐transplantation of BALB/c (H‐2d) islet tissue to normal CBA (H‐2k) recipients, but by 2–4 weeks post‐transplantation these animals return to their initial diabetic condition. Organ culture of allogeneic islet tissue in 95% O2and 5% CO2for 7 days prior to transplantation reduces the immunogenicity of the tissue, and cultured allografts give prolonged (>110 days) reversal of diabetes in normal allogeneic recipients. The non‐fasting blood sugar level remains in or very close to the normal range, urine glucose output is one to two orders of magnitude less than that of diabetic control animals and allografted animals regain their pre‐morbid body weight within 60 days of transplantation. Surgical removal of the allograft results in a rapid return of the animal to the initial diabetic condition.

ISSN:0004-945X    

DOI:10.1038/icb.1980.45

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryThe ability of tumour extracts to augment E‐rosette formation by cancer patients’ lymphocytes was demonstrated for colorectal carcinoma, breast carcinoma and melanoma. Positive augmentation reactions were obtained with 14 of 20 patients tested with extracts related to their own tumour types. Some lack of specificity was suggested by 5 positive reactions in the same patients tested with unrelated extracts. No false positives were found in normal subjects. The technique is simple, rapid and appears to depend on tumour‐associated antigens in the extracts. Simultaneous leucocyte adherence inhibition tests on split samples of blood had a high degree of sensitivity and specificity, confirming the potential reactivity of the leucocytes and extracts used.

ISSN:0004-945X    

DOI:10.1038/icb.1980.46

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryWhen spleen cells from mice injected 3 weeks or more previously with influenza A virus (responder cells) are mixed with normal spleen cells exposed 1 h previously lo influenza A virus (stimulator cells) and the mixture cultivated at 37° for 5–6 days, the surviving cell population contains effector T cells (Td) which can mediate delayed type hypersensitivity reactions. If infectious virus is used to prime both the donor mice and to infect the stimulator cells, the cell population also contains cytotoxic T cells (Tc). In this case, both Tc and Td have similar specificity patterns, as cells raised to one sub‐type A virus are cross‐reactive to other A strain viruses but not to Sendai virus. If non‐infectious virus is used to immunize the donor mice. Td but not Tc are generated and these cells are specific for the sub‐type A virus used in the original immunization. Both preparations of Td are Lyl+23−and require IA sharing of donor and recipient mice for transfer of DTH activity to be successful. Td cells produced this way are similar to those producedin vivoexcept they may have different migratory properties and must be injected directly into the footpad for DTH activity to be elicited. In such transfers. H‐2 restriction can be clearly demonstrated if the challenging antigen is injected into the footpad some hours before the injection of cells.

ISSN:0004-945X    

DOI:10.1038/icb.1980.47

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryCanine lymphoid cell preparations from blood, lymph node, spleen, thoracic‐duct lymph and thymus were examined for the presence of such surface markers as surface immunoglobulin, thymic‐specific antigen, Fc receptor and E‐rosette formation with normal (E) and neuraminidase‐treated (EN) human red blood cells. E‐RFC and EN‐RFC were further isolated and tested for reactivity in mixed lymphocyte culture.

ISSN:0004-945X    

DOI:10.1038/icb.1980.48

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryAntigenic stimulation of spleen mononuclear cells from contact‐sensitized mice produced a soluble factor that enhanced the formation of E‐rosettes by human lymphocytesin vitro. Production of this murine E‐rosette augmenting factor (E‐RAF) occurred over a narrow range of antigen concentrations, was hapten‐specific, and depended on T‐lymphocytes. The factor was not dialysable, in contrast to other substances extracted from normal leucocytes. Murine E‐RAF is thus a lymphokine whose action is not species restricted. It was readily detected 30 min after contact of cells with antigen. E‐RAF formation by spleen cells and delayed‐type hypersensitivity reactions were elicited over a similar period after contact sensitization of mice.

ISSN:0004-945X    

DOI:10.1038/icb.1980.49

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryUnstimulated mouse peritoneal macrophages can lyse certain tumour cell lines via the action of a labile exotoxin, some of the properties of which are examined.

ISSN:0004-945X    

DOI:10.1038/icb.1980.50

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryIn laboratory studies, Murray Valley encephalitis virus was transmitted transovarially by orally infectedAedes aegyptito approximately 1·5% of both adult male and female progeny.

ISSN:0004-945X    

DOI:10.1038/icb.1980.51

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryApparent kinetic constants (NADPH) have been calculated for NADPH‐cytochrome P450reductase and parahydroxylase in the presence of aniline with hepatic microsomes from both phenobarbital pre‐reated and untreated rats. The addition of NADH gave similar stimulation of both aniline parahydroxylation and NADPH‐cytochrome P450reductase activity in the presence of aniline. It is proposed that the increase in aniline metabolism with NADH is due to an increase in the NADPH‐cytochrome P450reductase activity which is rate limiting in microsomes from both phenobarbital and untreated rats.

ISSN:0004-945X    

DOI:10.1038/icb.1980.52

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryAbout a fifth of the ascorbic acid is readily lost from intestinal tissue during handling procedures such as washing with saline and blotting. Further losses occur during incubation in Krebs‐phosphate saline; after 10 min strips of intestine retained 80% of their original ascorbic acid content and chopped tissue only 50%. This suggests that some of the intestinal ascorbic acid is very loosely held in the tissue. The small intestine is capable of accumulating double the normal amount of ascorbic acid when animals are dosed intramuscularly and retains some ascorbic acid (0·7 to 5 μg/mg DNA) even when the animals' body stores are depleted.

ISSN:0004-945X    

DOI:10.1038/icb.1980.53

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY