摘要:

SummaryIn vivoandin vitroparameters of tumour resistance were examined after immunization of mice with the attenuated 11RX strain ofS. enteritidis.During the bacterial carrier state produced by intraperitoneal (i.p.) or intravenous (i.v.) injection of 11RX the mice were resistant to i.p. tumour growth, could destroy i.p. injected125I‐ or131I‐labelled tumour cellsin vivoand had non‐specifically cytotoxic peritoneal cells (PC) which could lyse51Cr‐labelled tumour cellsin vitro.Most of thein vivoandin vitrocytotoxic activity could be attributed to activated macrophages (La Postaet al., 1982). The predominantly local nature of 11RX‐induced anti‐tumour activity was indicated by the superiority of the i.p. route of infection for induction of tumour resistance andin vivoandin vitrocytotoxicity.After i.v. injection of 11RX, none of the anti‐tumour effects outlasted the bacterial carrier state. However, after i.p. infection, a dichotomy was observed betweenin vitroandin vivoanti‐tumour effects.In vitroPC cytotoxicity lasted only for the length of the 11RX carrier state (approximately 30 days), whereas resistance to i.p. tumour growth lasted for 60 to 100 days and was correlated closely with cytotoxic activity measuredin vivo.Possible reasons for this dichotomy are discussed.

ISSN:0004-945X    

DOI:10.1038/icb.1982.1

出版商:Nature Publishing Group    

年代:1982

数据来源: WILEY

摘要:

SummaryIn an attempt to characterize the effector cells responsible for tumour resistance inSalmonella enteritidis11RX‐immunized mice the anti‐macrophage agent trypan blue was used in bothin vivoandin vitroexperiments. Resistance was measuredin vivoby the clearance of125I from she peritoneal cavity of mice injected intraperitoneally with125I‐5‐iododeoxyuridine labelled Ehrlich Ascites Tumour (EAT) cells. Thein vitrocorrelate was measured by lysis of51Cr‐labelled tumour cells by peritoneal cells (PC) from 11RX‐immunized mice. Pre‐treatment of resistant mice with trypan blue greatly reduced both125I clearance and51Cr release. Thein vitrocytolytic activity was non‐specific.Fractionation of cytotoxic PC on the basis of adherence to plastic or nylon wool and buoyant density, coupled with the use of appropriate cell targets, showed that the bulk of cytotoxic activity resided with macrophages, with some contribution from other cells such as natural killer cells.Killing of labelled tumour cells could be inhibited by competition with unlabelled cells or by separating the PC and tumour cells by a cell impermeable membrane. This showed that close association between the effector and target cells was necessary before killing could occur.

ISSN:0004-945X    

DOI:10.1038/icb.1982.2

出版商:Nature Publishing Group    

年代:1982

数据来源: WILEY

摘要:

SummaryMononuclear cells cytotoxic to methylcholanthrene‐induced fibrosarcoma cells were detected in the peritoneal cavities of normal rats by means of 16 h51Cr release and 48 h125IUdR release assays. Carriage of a tumour which induces concomitant immunity, or intraperitoneal injections ofCorynebacterium parvumor proteose‐peptone, led to increases in mononuclear cell numbers. Injections ofC. parvumand proteose‐peptone led to increases in cytotoxicity in51Cr release assays. Carriage of an immunogenic tumour led to an increase in cytotoxicity to homologous tumour cells in the125IUdR release assay. Cells were separated by sedimentation velocity, metrizamide density gradients and adherence to glass or plastic. Small cells were more active than large cells in51Cr release assays. Larger cells tended to be more active in125IUdR release assays. Generally, low density cells were more active in both assays, except that high density cells induced byC. parvumwere most active in125IUdR release. Adherent cells fromC. parvum‐injected rats were more active than non‐adherent cells in both assays. On the basis of differential stimulation and separation by sedimentation velocity it is suggested that two cell types, possibly NK cells and macrophages, are operative.125IUdR‐labelled fibrosarcoma cells were lysed after intraperitoneal injection into normal and concomitantly immune rats, more rapidly and extensively in the latter case. These cytotoxic cells may be important in both natural and acquired resistance of rats to tumour growth.

ISSN:0004-945X    

DOI:10.1038/icb.1982.3

出版商:Nature Publishing Group    

年代:1982

数据来源: WILEY

摘要:

SummaryDietary restriction, adrenaline, hydrocortisone or surgery reduced the rate at which pulmonarily arrested125IUdR‐labelled murine tumour cells were lost within 7 h of intravenous (i.v.) injection. Mice that had been adrenalectomised 10 days previously showed a normal intrapulmonary tumour cell loss rate with further surgery reducing this rate to approximately half that observed in normal mice that had been subjected to surgery. Thus, although it is likely that adrenal hormones play an important role in decreasing the rate of early intrapulmonary tumour cell loss, additional factors must be implicated.Mice subject to dietary restriction, adrenaline, hydrocortisone or surgery had reduced levels ofin vitrogrowth inhibitor(s) in their sera. Despite this, individual surgically treated animals showed no correlation between serumin vitrogrowth inhibitor levels and rate of loss of i.v. injected tumour cells from the lungs. Furthermore, the 24 h pre‐incubation of tumour cells in inhibitor‐rich serum did not influence the subsequent loss rate of such cells following i.v. injection into mice.Electron microscopic studies indicated that dietary restriction, adrenaline and surgery reduced the rate of intravascular tumour cell death. The decreased tumour cell death rate in mice receiving these treatments could not be related, however, to any consistent morphological change in the pulmonary vasculature.The decreased rule of intravascular tumour cell death in treated mice was followed by an increased number of lung tumours with only one of the tumour lines studied, indicating that the intravascular death rate need not be a major determinant of pulmonary tumour incidence.

ISSN:0004-945X    

DOI:10.1038/icb.1982.4

出版商:Nature Publishing Group    

年代:1982

数据来源: WILEY

摘要:

SummaryThe effects of scab formation and the nature of the wound bed on the contraction of wounds have been investigated. Rabbit paraffin gauze dressed flank wounds with the panniculus carnosus intact and rat paraffin gauze dressed full skin thickness back wounds had constant linear rates of movement of the wound margins throughout the lime of contraction. Rabbit undressed wounds with the panniculus carnosus retained or excised and rat undressed wounds showed phases of rapid movement, no movement and normal movement of the wound margins during the course of contraction. These were effects of scab formation, they were transient and had little or no effect on the overall rate of wound contraction. The behaviour of rabbit undressed wounds with the panniculus excised was similar to that of comparable wounds with the panniculus intact, except that healing was delayed by approximately 3 days. Very variable behaviour was observed with rabbit paraffin gauze dressed wounds with the panniculus excised.

ISSN:0004-945X    

DOI:10.1038/icb.1982.5

出版商:Nature Publishing Group    

年代:1982

数据来源: WILEY

摘要:

SummaryPlasmodium falciparumcultures were synchronized using three lytic treatments with sorbitol. Schizonts from these cultures were used in a rapid, highly sensitive assay of invasion of erythrocytes by merozoites. The parasitaemias in recipient cells after invasion were determined by flow cytofluorimetry after staining with the dye 33258 Hoechst. Invasion of erythrocytes was shown to be reduced by serum from a patient with malaria. The assay is suitable for rapidly screening large numbers of samples, such as monoclonal antibodies.

ISSN:0004-945X    

DOI:10.1038/icb.1982.6

出版商:Nature Publishing Group    

年代:1982

数据来源: WILEY

摘要:

SummaryProteins from synchronized continuous cultures ofPlasmodium falciparumwere biosynthetically labelled with [35S]methionine at ring, trophozoite, and schizont stages. Several proteins appeared to be synthesized predominantly at one stage only, especially the schizont stage. Immunoprecipitation using inhibitory human sera revealed that a variety of proteins, from all stages of parasite growth, were recognized. More proteins, especially those with high molecular weight, were precipitated from the schizont stage than from ring and trophozoite stages, but two major proteins (MW ∼ 70,000 daltons and ∼ 45,000 daltons) were recognized in all three stages.

ISSN:0004-945X    

DOI:10.1038/icb.1982.7

出版商:Nature Publishing Group    

年代:1982

数据来源: WILEY

ISSN:0004-945X    

DOI:10.1038/icb.1982.8

出版商:Nature Publishing Group    

年代:1982

数据来源: WILEY

摘要:

SummaryThe changes induced by dietary xylitol in the gastrointestinal tract of the rat were investigated in relation to the phenomenon of vitamin‐sparing. Within 18 days of consuming a synthetic diet, deficient in thiamin, riboflavin and pyridoxine, rats ceased to grow and began to lose weight rapidly. If xylitol was then included in the diet (10% w/w), the effect of the vitamin‐deficient diet on growth was reversed. Moreover, within 3 days of the rats ingesting xylitol, the metabolism of this sugar polyol by the caecal microflora was increased 17‐fold and the caecal concentrations of thiamin and thiamin pyrophosphate were increased 5‐fold. Increases were also observed in the caecal size, the weight of the caecal contents, and the weight of the caecal wall. In contrast to the rapid changes observed within the caecum, liver thiamin pyrophosphate levels did not rise until 6–12 days after the feeding of xylitol, at which time the rats had begun to gain weight.The caecal contents were shown to contain facultative bacteria which have the ability to metabolise and grow on xylitol and which can, at the same time, synthesise thiamin. Species of the generaKlebsiella, SerratiaandMicrococcuswhich have this ability were isolated from the caecal contents of rats. It is assumed that coprophagy is the means by which the thiamin and other vitamins synthesised by enteral bacteria become available to the host, although some absorption from the caecum cannot be excluded.

ISSN:0004-945X    

DOI:10.1038/icb.1982.9

出版商:Nature Publishing Group    

年代:1982

数据来源: WILEY

摘要:

SummaryNuclear protein extracts from mononuclear cells in normal subjects, subjects with the clinical syndrome of thyroid hormone resistance and cultured B lymphocytes bound thyroxine (T4) (Ka; 1·3–3·5 × 109m−1) and triiodothyronine (T3) (Ka; 1·2–3·9 × 109m−1) with similar affinities. When an extra wash step was introduced, the maximum specific binding of T4and T3was reduced by 75% and binding was abolished by three washes. These data suggest binding is to a serum protein contaminant present in the mononuclear cell preparation.

ISSN:0004-945X    

DOI:10.1038/icb.1982.10

出版商:Nature Publishing Group    

年代:1982

数据来源: WILEY