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1.
Choosing a reliable source of tumor-specific T lymphocytes and an efficient method to isolate these cells still remains a critical issue in adoptive cellular therapy (ACT). In this study, we assessed the capacity of MHC/peptide based immunomagnetic sorting followed by polyclonal T cell expansion to derive pure polyclonal and tumor-reactive Melan-A specific T cell populations from melanoma patient’s PBMC and TIL. We first demonstrated that this approach was extremely efficient and reproducible. We then used this procedure to compare PBMC and TIL-derived cells from three melanoma patients in terms of avidity for Melan-A A27L analog, Melan-A26–35 and Melan-A27–35, tumor reactivity (lysis and cytokine production) and repertoire. Regardless of their origin, i.e., fresh PBMC, peptide stimulated PBMC or TIL, all sorted populations (from the three patients) were cytotoxic against HLA-A2+ melanoma cell lines expressing Melan-A. Although some variability in peptide avidity, lytic activity and cytokine production was observed between populations of different origins in a given patient, it differed from one patient to another and thus no correlation could be drawn between T cell source and reactivity. Analysis of Vβ usage within the sorted populations showed the recurrence of Vβ3 and Vβ14 subfamilies in the three patients but differences in the rest of the Melan-A repertoire. In addition, in two patients, we observed major repertoire differences between populations sorted from the three sources. We especially documented that in vitro peptide stimulation of PBMC, used to facilitate the sort by enriching in specific T lymphocytes, could significantly alter their repertoire and reactivity towards tumor cells. We conclude that PBMC which are easily obtained from all melanoma patients, can be as good a source as TIL to derive high amounts of tumor-reactive Melan-A specific T cells, with this selection/amplification procedure. However, the conditions of peptide stimulation should be improved to prevent a possible loss of reactive clonotypes. Nathalie Labarrière and Nadine Gervois have equally contributed to this work.  相似文献   

2.
A phase I/II study was conducted to test the feasibility and safety of the adoptive transfer of tumor-reactive T cells and daily injections of interferon-alpha (IFNα) in metastatic melanoma patients with progressive disease. Autologous melanoma cell lines were established to generate tumor-specific T cells by autologous mixed lymphocyte tumor cell cultures using peripheral blood lymphocytes. Ten patients were treated with on average 259 (range 38–474) million T cells per infusion to a maximum of six infusions, and clinical response was evaluated according to the response evaluation criteria in solid tumors (RECIST). Five patients showed clinical benefit from this treatment, including one complete regression, one partial response, and three patients with stable disease. No treatment-related serious adverse events were observed, except for the appearance of necrotic-like fingertips in one patient. An IFNα-related transient leucopenia was detected in 6 patients, including all responders. One responding patient displayed vitiligo. The infused T-cell batches consisted of tumor-reactive polyclonal CD8+ and/or CD4+ T cells. Clinical reactivity correlated with the functional properties of the infused tumor-specific T cells, including their in vitro expansion rate and the secretion of mainly Th1 cytokines as opposed to Th2 cytokines. Our study shows that relatively low doses of T cells and low-dose IFNα can lead to successful treatment of metastatic melanoma and reveals a number of parameters potentially associated with this success.  相似文献   

3.
Freshly isolated tumor-infiltrating lymphocytes (TIL) from stage IV melanoma patients were cultured for 2 weeks with low doses of interleukin-2 (IL-2; 120 IU/ml), to select potentially for tumor-specific lymphocytes present in the neoplastic lesion, followed by high doses (6000 IU/ml) to achieve lymphocyte expansion. TIL were serially analyzed for their expansion, phenotype and cytotoxic activity against autologous and allogeneic tumor cells. A preferential lysis of autologous melanoma cells was obtained in long-term cultures of 7/13 cases (54%), while the remaining ones showed a major-histocompatibility-complex-unrestricted, lymphokine-activated-killer(LAK)-like activity at the time of in vivo injection. Sixteen patients with metastatic melanoma were infused with TIL (mean number: 6.8×109, range: 0.35 × 109–20 × 109) and IL-2 (mean dose: 130 × 106 IU, range: 28.8 × 106–231 × 106 IU); 1 complete and 3 partial responses were observed in 12 evaluable patients (response rate 33%). In all responding patients, injected TIL showed an in vitro preferential lysis of autologous tumor cells, while in no cases were TIL with LAK-like activity associated with a clinical response. The mean autologous tumor cytotoxic activity of TIL at the time of in vivo injection was significantly higher in responding patients in comparison to nonresponding ones, suggesting that a marked and preferential cytolysis of autologous tumor cells is associated with the therapeutic efficacy of TIL.  相似文献   

4.
Background aimsAdoptive transfer of tumor-infiltrating lymphocytes (TIL) has proven effective in metastatic melanoma and should therefore be explored in other types of cancer. The aim of this study was to examine the feasibility of potentially expanding clinically relevant quantities of tumor-specific T-cell cultures from TIL from patients with head and neck squamous cell carcinoma (HNSCC) using a more rapid expansion procedure compared with previous HNSCC studies.MethodsIn a two-step expansion process, initially TIL bulk cultures were established from primary and recurrent HNSCC tumors in high-dose interleukin (IL)-2. Secondly, selected bulk cultures were rapidly expanded using anti-CD3 antibody, feeder cells and high-dose IL-2. T-cell subsets were phenotypically characterized using flow cytometry. T-cell receptor (TCR) clonotype mapping was applied to examine clonotype dynamics during culture. Interferon (INF)-γ detection by Elispot and Cr51 release assay determined the specificity and functional capacity of selected TIL pre- and post-rapid expansion.ResultsTIL bulk cultures were expanded in 80% of the patients included, showing tumor specificity in 60% of the patients. Rapid expansions generated up to 3500-fold expansion of selected TIL cultures within 17 days. The cultures mainly consisted of T-effector memory cells, with varying distributions of CD8+ and CD4+ subtypes both among cultures and patients. TCR clonotype mapping demonstrated oligoclonal expanded cultures, ranging from approximately 10 to 30 T-cell clonotypes. TIL from large-scale rapid expansions maintained functional capacity, and contained tumor-specific T cells.ConclusionThe procedure is feasible for expansion of TIL from HNSCC, ensuring clinically relevant expansion folds within 7 weeks. The cell culture kinetics and phenotypes of the TIL resemble previously published results on TIL from melanoma, setting the stage for clinical testing of this promising treatment strategy for patients with HNSCC.  相似文献   

5.
 The generation of cytotoxic effector T cells requires delivery of two signals, one derived from a specific antigenic epitope and one from a costimulatory molecule. A phase I clinical trial was conducted with a non-replicating canarypoxvirus (ALVAC) constructed to express both human carcinoembryonic antigen (CEA) and the B7.1 costimulatory molecule. This was the first study in cancer patients to determine if the delivery of costimulation with a tumor vaccine was feasible and improved immune responses. Three cohorts of six patients, each with advanced CEA-expressing adenocarcinomas, were treated with increasing doses of an ALVAC-CEA-B7.1 vaccine (4.5 × 106, 4.5 × 107, and 4.5 × 108 plaque-forming units, PFU). Patients were vaccinated by intramuscular injection every 4 weeks for 3 months and monitored for side-effects, tumor growth and anti-CEA immune responses. ALVAC-CEA- B7.1 at doses up to 4.5 × 108 PFU was given without evidence of significant toxicity or autoimmune reactions. Three patients experienced clinically stable disease that correlated with increasing CEA-specific precursor T cells, as shown by in vitro interferon-γ enzyme-linked immunoassay spot tests (ELISPOT). These three patients underwent repeated vaccination resulting in augmented CEA-specific T cell responses. This study represents the first use of costimulation to enhance antitumor vaccines in cancer patients. This approach resulted in CEA-specific immunity associated with stable diseases in three patients. This study also demonstrated that CEA-specific T cell responses could be sustained by repeated vaccinations. Although the number of patients was small, the addition of B7.1 to virus-based vaccines may improve immunological and stable diseases to vaccination against tumor-associated antigens with tolerable toxicity. Received: 6 May 2000 / Accepted: 13 July 2000  相似文献   

6.
 Adoptive tumour infiltrating lymphocytes (TIL) in combination with a modulated dosage of interleukin-2 (IL-2) can be used with acceptable toxicity in the treatment of immunogenic tumours. Following an experience of reinfusion in advanced melanoma, colorectal and renal cancer patients, treatment was given to disease-free patients after metastasectomy. The high risk of relapse and favourable ratio between reinfused TIL and possible microscopic residual disease determined this choice of adjuvant treatment. A group of 12 patients with advanced disease (7 melanoma, 4 colorectal carcinoma, 1 kidney carcinoma) were treated with TIL (median 5.8×1010 cells) and IL-2 (West’s schedule) modulated towards a lower dosage (from 12 to 6 MIU/day) in order to maintain an acceptable level of toxicity. As treatment was well tolerated, it was offered to another 22 patients in an adjuvant setting after metastasectomy (11 melanoma, 10 colorectal carcinoma, 1 renal cancer), the median dose of TIL reinfused being 4.95×1010 cells. No objective response was observed in advanced patients: all patients progressed after a median of 1.5 months (0–8 months) and median survival was 8 months (3–22+ months). Thirteen patients from the second group are still disease-free after a median of 23+ months (9+–47+ months). The remaining 9 patients relapsed after a median of 5 months (3–18 months). Toxicity was moderate as clinical and hepatic/renal function parameters were used to assess the need for dose reductions. Consequently, there was great diversity in IL-2 dosages administered. In particular, there seemed to be a difference in IL-2 doses administered between disease-free cases and those who progressed (17.5 MIU/day versus 7 MIU/day in melanoma patients; 11.2 MIU/day versus 7.1 MIU/day in colorectal cancer patients). By contrast, no differences were observed between number of TIL reinfused and clinical response. Phenotypical characteristics of reinfused TIL were similar to those reported in the literature: 97% were CD3 and 92% were CD8. Aspecific cytolytic activity was evaluated on 12 cases whereas, in 2 melanoma cases, autologous tumour tissue was available for the specific cytotoxicity test. Perforin levels in TIL measured at the end of culture were generally high or very high. Cytokine levels were measured on the supernatant at the end of culture, with an estreme variability in results. Finally, ζ chain and p56lck were histologically assessed on the resected tissue from which TIL were cultivated. There were virtually none of the former and a complete absence of the latter, which concurs with data reported in the literature. The same immunocytochemical analysis was carried out on TIL at the end of culture. This time an almost complete restoration of both functions was seen, especially in melanoma patients, who are still free from disease. The study is on-going and it has been decided to focus on disease-free patients after metastasectomy in order to increase the number and possibility of clinical and histological correlations.  相似文献   

7.
  The ability of the lymphocytes to move through the interstitium is obligatory to the immune response. We previously showed that tumor-infiltrating lymphocytes (TIL) from human melanoma and renal cell carcinoma demonstrate a dramatic decrease in their spontaneous locomotion through three-dimensional collagen gel when compared with peripheral blood lymphocytes (PBL) and lymph node lymphocytes. To determine if this decrease is caused by contact with tumor cells, or mediated through certain diffusible factors, we examined the effects of autologous tumor cells on the locomotion of PBL in a model system where tumor cells were separated from lymphocytes by a 3-mm layer of gelled collagen. After 21–22 h incubation in chamber slides, locomotion distances were assessed in the presence and absence of tumor and normal cells. In the presence of tumor cells, PBL from 14 of 18 patients displayed substantial (466.5 ±2.7 μm compared to control 568.9 ± 10.9 μm, P<0.001) loss of motility. Inhibition was more prominent in melanoma patients than in renal cell carcinoma patients. Thus the impaired locomotion previously observed in TIL was at least partially due to the presence of tumor. The locomotion of TIL was restored in four of five melanoma patients treated with liposome-encapsulated muramyl-tripeptide-phosphatidylethanolamine (L-MTP-PE). Furthermore, in six of seven examined L-MTP-PE-treated patients, an increase in intrinsic PBL locomotion during the first month of the therapy was observed. These results suggest that the environment of the tumor is not conducive to locomotion of advancing lymphocytes and the therapeutic intervention may ameliorate the loss of lymphocytic infiltration. Received: 16 May 1994 / Accepted: 26 August 1994  相似文献   

8.
 Adoptive immunotherapy (AIT) of cancer with T lymphocytes may be limited by the need to activate tumor antigen-sensitized cells in vitro. In murine models, we have shown that AIT with tumor-sensitized T cells that have been pharmacologically activated with bryostatin 1 and ionomycin plus interleukin-2 can induce tumor regression. A Phase I clinical trial was carried out to assess the feasibility and toxicity associated with using tumor- or vaccine-draining lymph node cells, activated pharmacologically and expanded in culture with low-dose interleukin-2 and infused intravenously, followed by IL-2 infusion. Nine patients were entered into the trial, and six were treated as planned. Average expansion of cell numbers over 13 to 27 days in culture was 118-fold. No patient's cells reached the target cell number (2.5 × 1010). Infusion of these cells did not result in any unexpected toxicities. The toxicities observed were related to IL-2 infusion, and conformed to the expected range of side-effects. Based on these Phase I results, additional trials, with tumor antigen vaccine-sensitized DLN and technical modifications of the culture technique, are planned. Received: 18 January 2001 / Accepted: 26 April 2001  相似文献   

9.
Purpose: Most melanoma cell lines express HLA class II antigens constitutively or can be induced to do so with interferon γ (IFNγ). We have previously demonstrated that peptide-specific CD4+ T cells proliferate in response to HLA-class-II-antigen-mediated peptide presentation by melanoma cells in vitro and produce interleukin-10 (IL-10) and (IFNγ). We asked whether the responding T cells kill the tumor cells and, if so, whether direct cell contact was required. Methods: Two HLA class II+ melanoma cell lines derived from metastases were co-cultured with a human CD4+ T cell clone specific for influenza hemagglutinin peptide (HA). T cells, melanoma, and HA were co-cultured for 48 h. Melanoma cells with and without HA and/or T cells served as controls. After 36 h, the medium was removed for cytokine analysis by enzyme-linked immunosorbent assay (ELISA). Twelve hours later non-adherent cells were washed away and the adherent melanoma cells were trypsinized and counted. Dual-chamber culture plates were used to determine whether cell contact and/or exposure to cytokine were required for tumor cell death. Results: Melanoma cell counts were over 80% lower in wells containing T cells than in wells with melanoma and peptide alone (P < 0.05). ELISA of supernatants revealed production of IFNγ and IL-10 by the responding T cells. Direct T cell contact with tumor cells was not required for tumor cell death, as melanoma cells were killed when they shared medium but had no contact with T cells responding to peptide presentation by HLA-class-II-antigen-positive melanoma cells in a separate chamber. Blocking antibody to IFNγ but not IL-10 prevented melanoma cell death at levels of cytokine similar to that present in co-culture assays. Conclusions: Peptide-specific CD4+ T cells kill melanoma cells in vitro when they recognize peptide presented by the tumor cell in the context of HLA class II antigen. Direct cell contact is not required, suggesting that it is a cytokine-mediated event. Immunotherapy, using primed CD4+ T cells and peptide, may be beneficial in patients whose tumors express HLA class II antigens or can be induced to do so with IFNγ. Received: 1 July 1999 / Accepted: 17 September 1999  相似文献   

10.
11.
 Dendritic cells (DCs) can be the principal initiators of antigen-specific immune responses. We analyzed the in vitro-responses against brain tumor cells using DCs from the peripheral blood of patients with brain tumors. Peripheral blood mononuclear cells (PBMC) were obtained from 19 patients with malignant brain tumors: 12 metastatic brain tumors of lung adenocarcinoma, 7 high-grade astrocytomas. PBMC were cultured with 100 ng/ml of GM-CSF and 10 ng/ml of IL-4 for 5–7 days in order to produce mature DCs. The autologous tumor lysate (5 mg/ml, containing 1 × 106 cells) was then added to the cultured DCs. Using the DCs generated by these treatments, we assessed the changes that occurred in their immune responses against brain tumor via 51Cr-release and lymphocyte proliferation assays. We found that the matured DCs displayed the typical surface phenotype of CD3+, CD45+, CD80+ and CD86+. After the pulsation treatment with tumor lysate, DCs were found to have strong cytotoxic T lymphocyte activity, showing 42.5 ± 12.7% killing of autologous tumor cells. We also found an enhancement of allogeneic T cell proliferation after pulsing the DC with tumor lysate. These data support the efficacy of DC-based immunotherapy for patients with malignant brain tumors. Received: 2 October 2000 / Accepted: 26 April 2001  相似文献   

12.
Summary GD3 is expressed in high concentrations on melanoma cells and may serve as a useful target antigen for mAb-mediated immunotherapy. Monoclonal antibodies (mAbs) against GD3 stimulate cell-mediated immune responses against tumor cells in vitro and this activity may contribute to antitumor effects in patients with melanoma treated with GD3-reactive mAbs. In the present study the effects of GD3-reactive mAbs on autologous tumor cell lysis by a human melanoma-derived tumor-infiltrating lymphocyte (TIL) population were examined. Unlike results reported for other GD3+ T cells isolated from melanoma patients, the tumor-specific lytic activity of the TIL line was inhibited by incubation with mAbs against GD3. Other melanoma-reactive mAbs, including those against GD2 and the high-molecular-weight melanoma-associated Ag, had no effect on the TIL lytic activity. Overall, these results indicate that mAbs against GD3 may have different effects on T cell/tumor cell interactions.  相似文献   

13.
Arctic Sea ice biota: design and evaluation of a mesocosm experiment   总被引:1,自引:0,他引:1  
A mesocosm experiment (enclosure volume 220 l) was designed such that sea ice inhabited by Arctic Sea ice organisms was formed and maintained under natural conditions at 66°N in Rovaniemi, Finland. The experiment was run from natural freezing in December 1994 to melting in April 1995. The ice was inhabited by diatoms, chlorophyceae, heterotrophic flagellates, ciliates, nematodes and turbellarians. Biomass in the ice, expressed as Chlorophyll a concentration, was 20–110 μg l−1; total cell densities varied from 5 × 106 to 35 × 106 cells l−1. Amongst phototrophic organisms, a succession from a flagellate-dominated community (Chlamydomonas sp.) to a multi-species diatom-dominated community was observed. Typical Arctic species such as Nitzschia frigida and Melosira arctica were present in the ice. Bacterial concentration varied between 2 × 108 and 7 × 108 cells l−1. At least two trophic levels were present in the ice. Received: 3 April 1997 / Accepted: 9 September 1997  相似文献   

14.
Tumor-specific memory T cells are detectable in the bone marrow (BM) of a majority of breast cancer patients. In vitro they can be reactivated to IFN-γ producing, cytotoxic effector cells and reject autologous, xenotransplanted tumors in NOD/SCID mice after specific restimulation with autologous dendritic cells (DC). In this study, we demonstrate the presence of specific tumor-reactive BM memory T cells in altogether 56 out of 129 primarily operated breast cancer patients by short-term IFN-γ EliSpot assays with unstimulated T cells and tumor antigen presenting, autologous DCs. We observed tumor-reactive BM memory T cells predominantly in patients with primarily metastatic disease (P = 0.011) or with increased concentrations of tumor marker CA 15-3 in the peripheral blood (P = 0.004), respectively. Memory T cell reactivity against HLA-A*0201-restricted peptides from the tumor-associated antigens MUC1, Hpa16–24 and Hpa183–191 was also detected particularly in patients with elevated peripheral CA 15-3 concentrations (P < 0.05). Altogether these data indicate that the systemic presence of tumor-derived antigens promotes an induction of tumor-specific cellular immune responses in the human BM.  相似文献   

15.
The methylotrophic yeast Pichia pastoris has been used for the expression of many proteins. However, limitations such as protein degradation and aggregation became obvious when secreting heterologous protein-recombinant human consensus interferon-α mutant. Here, we investigate the effect of induction temperature on the yield and stability of interferon mutant expressed by P. patoris with buffered complex medium. The best results in terms of interferon mutant bioactivity and specific bioactivity were obtained when the microorganism was induced at 15°C, which were 2.91 × 108 ± 0.3 × 108 and 2.26 × 108 ± 0.23 × 108 IU mg−1, respectively. At the same time, the cells grew fast owing to high AOX1-specific activity, and interferon mutant expression level reached 1.23 g l−1, which was almost 30 times higher than that in the flask. Also, the proteolytic degradation of interferon mutant was inhibited completely because of lower protease bioactivity probably due to a reduced cell death rate at lower temperatures as well as protection of yeast extract and peptone in complex medium. In addition, interferon mutant aggregation was repressed significantly by the addition of Tween-80, and a specific bioactivity of 7.35 × 108 ± 0.56 × 108 IU mg−1 was obtained. These results should be applicable to other low-stability recombinant proteins expressed in P. pastoris.  相似文献   

16.
A Pseudomonas sp. strain NGK 1 (NCIM 5120) was immobilized in various matrices, namely, alginate, agar (1.8 × 1011 cfu g−1 beads) and polyacrylamide (1.6 × 1011 cfu g−1 beads). The degradation of naphthalene was studied, by freely suspended cells (4 × 1010 cfu ml−1) and immobilized cells in batches, with shaken culture and continuous degradation in a packed-bed reactor. Free cells brought about the complete degradation of 25 mmol naphthalene after 3 days of incubation, whereas, a maximum of 30 mmol naphthalene was degraded by the bacteria after 3–4 days of incubation with 50 mmol and 75 mmol naphthalene, and no further degradation was observed even after 15 days of incubation. Alginate-entrapped cells had degraded 25 mmol naphthalene after 3.5 days of incubation, whereas agar- and polyacrylamide-entrapped cells took 2.5 days; 50 mmol naphthalene was completely degraded by the immobilized cells after 6–7 days of incubation. Maximum amounts of 55 mmol, 70 mmol and 67 mmol naphthalene were degraded, from an initial 75 mmol naphthalene, by the alginate-, agar- and polyacrylamide-entrapped cells after 15 days of incubation. When the cell concentrations were doubled, 25 mmol and 50 mmol naphthalene were degraded after 2 and 5.5 days of incubation by the immobilized cells. Complete degradation of 75 mmol naphthalene occurred after 10 days incubation with agar- and polyacrylamide-entrapped␣cells, whereas only 60 mmol naphthalene was degraded by alginate-entrapped cells after 15 days of␣incubation. Further, with 25 mmol naphthalene, alginate-, agar- and polyacrylamide-entrapped cells (1.8 × 1011 cfu g−1 beads) could be reused 18, 12 and 23 times respectively. During continuous degradation in a packed-bed reactor, 80 mmol naphthalene 100 ml−1 h−1 was degraded by alginate- and polyacrylamide-entrapped cells whereas 80 mmol naphthalene 125 ml−1␣h−1 was degraded by agar-entrapped cells. Received: 21 October 1997 / Received revision: 15 January 1998 / Accepted: 18 January 1998  相似文献   

17.
AHSP inhibits cellular production of the reactive oxygen species. Reduced AHSP indicates reduced protection against oxidative stressors. Our objective was to investigate AHSP levels in recurrent miscarriage (RM). Trophoblast was collected from women of 10 weeks gestation: voluntary abortion controls (VA, n = 10); spontaneous first miscarriage with subsequent normal pregnancy (SMSN, n = 15) or with subsequent miscarriage (SMSM, n = 5); RM previously investigated (RMPS, n = 5) or not previously investigated (RM, n = 5). AHSP mRNA and protein were determined using real-time quantitative polymerase chain reaction (PCR) and Western blot, respectively. One-way ANOVA was performed to assess statistical significance (p < 0.05). ahsp mRNA levels were maximally reduced in RM and RMPS (8.0 × 10−6 ± 1.3 and 8.1 × 10−6 ± 0.7, respectively) compared with SMSN and VA (16.1 × 10−6 ± 2.3 and 26.1 × 10−6 ± 2.7, respectively). SMSM showed levels significantly reduced as well (9.0 × 10−6 ± 2.3). In RM, a reduced defense from oxidative stressors is evident at first miscarriage, identifying women at high risk for subsequent eventful pregnancy. Reduced AHSP may identify women at risk of experiencing further miscarriages. Monica Emanuelli and Monia Cecati contributed equally to this paper.  相似文献   

18.
Lipids are important entomopathogenic nematode nutritional components because they are energy reserves and serve as indicators of nematode quality. The composition and concentration of the media lipid component determine bacterial and nematode yields. Heterorhabditis bacteriophora and its symbiont, Photorhabdus luminescens, were cultured in media containing various lipid sources. As lipid concentration increased from 2.5% to 8.0% (w/v), the final yield and productivity [calculated from the number of infective juveniles (IJ)] increased significantly from 2.1 × 105 IJ ml−1 to 2.8 × 105 IJ ml−1 (P < 0.05) and from 8.9 × 105 IJ l−1 day−1 to 11.8 × 105 IJ l−1 day−1 (P < 0.05), respectively. The nematode yield coefficient (IJ per gram of media), however, decreased from 2.8 × 106 to 2.2 × 106 (P < 0.05), while recovery increased from 45.3% to 58.0% (P < 0.05). Bacterial cell mass remained constant at 4.6 mg ml−1 with changing lipid content (P > 0.05). The largest nematode yield (2.8 × 105 IJ ml−1) was achieved within 8 days, using a medium containing an 8% (w/v) olive and canola oil (50:50 w/v) combination. Moreover, developmental synchrony was achieved in this medium with 96% infective juveniles. In short, lipid sources rich in mono-unsaturated fatty acids and poor in saturated fatty acids produced optimal nematode growth. Received: 1 May 2000 / Received revision: 17 July 2000 / Accepted: 27 July 2000  相似文献   

19.
 The migratory history of Anguilla dieffenbachii and A. australis, collected from a coastal lake of New Zealand, was examined using analysis of strontium (Sr) and calcium (Ca) concentrations. Line analysis of Sr : Ca ratios along the life history transect of each otolith showed a peak (Ca. 16–20 × 10−3) between the core and elver mark, which corresponded to the period of their leptocephalus and early glass eel stages in the ocean. The mean Sr : Ca ratios from the elver mark to the otolith edge indicated that eels had different migratory histories, which included freshwater residency in some eels (average Sr : Ca ratios, 1.7 × 10−3–2.4 × 10−3) but not in others (average Sr : Ca ratios, 3.1 × 10−3–6.5 × 10−3). These findings suggest that New Zealand freshwater eels have a flexible migration strategy and an ability to adapt to various habitats and salinities. Received: November 25, 2002 / Revised: January 17, 2003 / Accepted: January 17, 2003  相似文献   

20.
Signaling defects in T lymphocytes of patients with malignancy   总被引:12,自引:0,他引:12  
In patients with cancer, alterations in the expression of T-cell receptor-associated molecules in tumor-infiltrating lymphocytes (TIL) as well as in circulating lymphocytes have been reported. By quantitative flow cytometry analysis, decreased or absent expression of the ζ chain in CD4+ or CD8+ T cells as well as in natural killer (NK) cells was demonstrated in patients with malignancies. Changes in the expression of ζ are biologically significant, because the absence or low expression of this signaling molecule in TIL of patients with stage III or IV head and neck cancer predicts a significantly shorter 5-year survival than that of patients with normal ζ expression in TIL. Preliminary evidence indicates that expression of ζ in TIL may not only influence survival but also predicts a favorable response to biologic therapies. Patients with cancer also show significantly greater spontaneous ex vivo apoptosis in peripheral blood mononuclear cells (PBMC) compared to normal controls, as measured by a terminal deoxynucleotide transferase-mediated dUTP nick end labeling (TUNEL) assay. While no correlation could be established between the proportions of cells with low ζ chain expression and those that spontaneously apoptose ex vivo, the ζ chain has been shown to be cleaved by caspases in T cells coincubated with tumor cells or with T cells exposed to CH-11 antibody, which induces apoptosis upon crosslinking Fas on the cell surface. The results suggest that low/absent ζ chain expression and lymphocyte apoptosis may be manifestations of negative effects of the tumor on the host immune system. Received: 20 March 1999 / Accepted: 3 May 1999  相似文献   

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