Cisplatin plus 5-FU for the treatment of adenocarcinoma of the colon

Cisplatin plus 5-FU appears to have significant additive activity in various tumors, such as head and neck carcinoma and esophageal cancer. A partial explanation for this may be drug synergism, which has been noted in the L1210 leukemia model. Based on these data, a prospective trial of weekly bolus 5-FU (15 mg/kg) and cisplatin (60 mg/m2) given every 3 weeks was initiated at Indiana University. Forty-one patients, of whom 38 are fully evaluable for response, were treated with these two drugs. Ten partial and one complete response (complete + partial response rate = 29%) were observed in the 38 evaluable patients. Thirteen additional patients had stable disease for greater than or equal to 3 months. The median durations of remission and survival time were 6 and 10.3 months, respectively. Myelosuppression was unusually severe, with granulocyte counts less than 1000/mm3 in 65% of patients, including four patients with granulocyte count nadirs less than 100/mm3. Three patients developed granulocytopenic fever, with two drug-related deaths (sepsis, hyperosmolar coma). Nearly all patients had nausea and vomiting, but this was not a treatment-limiting toxic effect in any patient. Although this combination suggests a higher response rate than usually seen with bolus iv 5-FU in colon cancer, a trial comparing 5-FU alone or with cisplatin to determine whether true synergy exists is currently underway.     

Cytogenetic studies in non-African Burkitt lymphoma

A particular translocation between chromosomes 8 and 14 has been found repeatedly in cytogenetic studies of Burkitt lymphoma, both of African and non-African origin. We report here our findings in cytogenetic studies of direct tumor preparations from 18 non-African Burkitt lymphoma patients, 9 of whom also had cell lines available for study. A t(8;14) was found in direct tumor material in 10 of the 18 patients. Seven of the 9 cell lines had a t(8;14). A total of 15 patients had either a t(8;14) or a 14q+ present in tumor material and/or cell lines. In addition, 8 patients had a peculiar marker chromosome 1. The t(8;14) was not found in every malignant cell and, where present, it was rarely the sole karyotypic abnormality. The relationship of the t(8;14) to the evolution of the tumor is discussed.     

Active immunization of murine allogeneic bone marrow transplant donors with B-cell tumor-derived idiotype: a strategy for enhancing the specific antitumor effect of marrow grafts

Persistence of the underlying malignancy remains the major obstacle limiting the success of high-dose chemoradiotherapy with allogeneic bone marrow transplantation (BMT) for lymphomas and multiple myeloma. We used the C3H 38C13 murine B-cell lymphoma, which expresses and secretes clonally derived Ig, the idiotype of which can serve as a tumor-specific antigen, to test the principle of transfer of tumor idiotype-specific immunity with BM. BALB/c marrow donors were twice immunized with 38C13-derived Ig, or with an isotype-matched control Ig, conjugated to keyhole limpet hemocyanin. Lethally irradiated C3H recipients reconstituted with marrow from idiotype immune, but not nonspecifically immune, donors demonstrated protection against subsequent lethal tumor challenge. The immunoprotective effect of immune allogeneic marrow was abrogated by T-cell depletion of the marrow graft before infusion. Low levels of serum anti-idiotypic antibody remained unaltered in recipients of T-cell-depleted immune marrow, consistent with a primary role for T-cell immunity in the cellular mechanism of this phenomenon. A modest therapeutic effect of immune allogeneic marrow was observed against 10 day, 1 cm established subcutaneous tumors, but only in combination with a booster immunization of the recipient post-BMT. These results provide the rationale for a novel strategy for enhancing the specific antitumor effect of allogeneic marrow grafts.     

Maternal dietary ethanol consumption is associated with hypertriglyceridemia in adult rat offspring

BACKGROUND: The consumption of significant amounts of alcohol (ethanol, EtOH) may markedly increase serum triglyceride levels. This study describes a significant increase in fasting serum triglyceride (TG) levels in adult male rats whose mothers consumed EtOH. The hypertriglyceridemia occurred although the offspring never directly consumed EtOH and had consumed only rat chow for the preceding 14 months. Furthermore, both male and female adult offspring had an additional, significant increase in TG levels if their mothers consumed EtOH and experienced stress (restraint) during the pregnancy. METHODS: Harlan-derived Sprague Dawley female rats were dosed during pregnancy with EtOH via a liquid diet, and their offspring were compared with offspring of mothers who were either fed ad libitum or pair-fed the liquid diet without EtOH. At birth, the offspring of EtOH mothers exhibited no visible abnormalities except reduced weight, and all offspring were surrogate fostered within 48 hr of birth to mothers who had consumed commercial rat chow throughout their pregnancy. After weaning, all offspring consumed only commercial rat chow, and they were examined over the next 14 months for changes in triglyceride homeostasis as a function of maternal alcohol intake. RESULTS: Adult male offspring of mothers that consumed EtOH during their pregnancy had significant increases in fasting serum triglycerides associated with an increase in the very low density lipoprotein serum fraction. Acute administration of insulin to the offspring of all maternal dietary groups resulted in a rapid clearing of the serum triglycerides, and there were no differences in basal or heparin-releasable lipoprotein lipase activity between any of the progeny. Castration of the male offspring of EtOH-treated mothers prevented the development of elevated TG levels. Administration of testosterone to littermate female offspring increased circulating TG levels compared with testosterone-treated offspring of pair-fed mothers. EtOH-consuming mothers who also underwent five periods of restraint-induced stress (approximately 10 min each session) produced offspring whose fasting serum TG levels were higher than those whose mothers consumed EtOH but experienced no restraint or who experienced restraint but no EtOH. Maternal stress significantly reduced lipoprotein lipase activity in some offspring treatment groups, but the changes did not correspond to changes in the serum TG levels of the offspring. That is, maternal restraint-induced stress was associated with a loss of heparin-releasable lipoprotein lipase activity by male progeny from pair-fed and EtOH-fed mothers and the female offspring of ad libitum-fed and EtOH-fed mothers. CONCLUSIONS: Although serum triglycerides increased with age in all offspring, the increase was much more pronounced in the progeny of mothers who consumed EtOH during their pregnancy. The hypertriglyceridemia was significantly more pronounced in the male offspring and in female offspring treated with testosterone. Castration of male offspring inhibited the hypertriglyceridemia development, which suggests that male sex hormones may play a role in the development of this condition. Maternal EtOH consumption coupled with maternal restraint-induced stress significantly increased the level of hypertriglyceridemia in both male and female offspring compared with offspring whose mothers experienced restraint but no EtOH or EtOH with no restraint. If this study models the human condition, the results could represent an unrecognized risk factor in a number of adult disease states hypothesized to be associated with hypertriglyceridemia, such as cardiovascular disease, hypertension, and diabetes.     

Murine CD27(?) Vγ6(+) γδ T cells producing IL-17A promote ovarian cancer growth via mobilization of protumor small peritoneal macrophages

Cancer-associated inflammation mobilizes a variety of leukocyte populations that can inhibit or enhance tumor cell growth in situ. These subsets include γδ T cells, which can infiltrate tumors and typically provide large amounts of antitumor cytokines, such as IFN-γ. By contrast, we report here that in a well-established transplantable (ID8 cell line) model of peritoneal/ovarian cancer, γδ T cells promote tumor cell growth. γδ T cells accumulated in the peritoneal cavity in response to tumor challenge and could be visualized within solid tumor foci. Functional characterization of tumor-associated γδ T cells revealed preferential production of interleukin-17A (IL-17), rather than IFN-γ. Consistent with this finding, both T cell receptor (TCR)δ-deficient and IL-17–deficient mice displayed reduced ID8 tumor growth compared with wild-type animals. IL-17 production by γδ T cells in the tumor environment was essentially restricted to a highly proliferative CD27⁽⁻⁾ subset that expressed Vγ6 instead of the more common Vγ1 and Vγ4 TCR chains. The preferential expansion of IL-17–secreting CD27⁽⁻⁾ Vγ6⁽⁺⁾ γδ T cells associated with the selective mobilization of unconventional small peritoneal macrophages (SPMs) that, in comparison with large peritoneal macrophages, were enriched for IL-17 receptor A, and for protumor and proangiogenic molecular mediators, which were up-regulated by IL-17. Importantly, SPMs were uniquely and directly capable of promoting ovarian cancer cell proliferation. Collectively, this work identifies an IL-17–dependent lymphoid/myeloid cross-talk involving γδ T cells and SPMs that promotes tumor cell growth and thus counteracts cancer immunosurveillance.Developing tumors are infiltrated by a variety of leukocyte subsets that can either promote or inhibit inflammation, and thus impact on cancer progression (1). Among such populations are γδ T cells, which are major players in lymphoid stress surveillance likely due to their recognition of stress-inducible molecules independently of MHC-mediated antigen presentation (2). Moreover, abundant IFN-γ secretion and cytotoxic effector functions endow γδ T cells with potent antitumor activity. This has been clearly documented in murine models of spontaneous (3), chemically induced (4), transgenic (5), and transplantable (6, 7) tumors. For example, in the widely used B16 melanoma model, γδ T cells were shown to infiltrate tumors very early and provided a critical source of IFN-γ that significantly delayed tumor growth (6, 7).Human γδ T cells also possess IFN-γ–secreting potential, which is displayed immediately at birth (8) and display cytotoxicity against tumor lines of diverse origin, including epithelial (9, 10) and hematological (11, 12) tumors. This has prompted the development of cancer clinical trials targeting γδ T cells, which have produced encouraging, albeit highly variable, degrees of therapeutic responses (13–15). There is therefore great interest in maximizing the antitumor functions of γδ T cells for cancer immunotherapy.Despite these highly promising reports, a clinical study on breast cancer tissue revealed a surprising inverse correlation between infiltrating γδ T cells and overall patient survival (16). In fact, γδ T cells represented the most significant independent prognostic factor for assessing severity of breast cancer (16). Similarly, a recent report on colorectal cancer showed a positive correlation between clinopathological parameters and the infiltration of γδ T cells specifically producing interleukin-17 (IL-17) (17). A tumor-promoting function of γδ T cells was also suggested in murine fibrosarcoma (18) and hepatocellular carcinoma (19) models, in which γδ T cells were the major cellular source of IL-17, which was required for optimal tumor growth in vivo. These data raise the interesting question as to whether distinct functional attributes of γδ T cells, for example differential cytokine production, may associate with markedly different outcomes for tumor growth.Along these lines, we have pioneered the identification of two distinct functional subsets of murine γδ T cells based on the expression levels of the CD27 coreceptor (20). We showed that robust IFN-γ production is associated with the CD27⁽⁺⁾ phenotype, whereas secretion of IL-17 is restricted to CD27⁽⁻⁾ γδ T cells. This dichotomy of hard-wired commitment to specific cytokine production is established during thymic development and maintained during the immune response to various infection agents (21, 22). Thus, the overall impact of γδ T cells in a given disease may depend on the balance between distinct proinflammatory effector cell subsets.Building on these foundations, we have here analyzed the overall and subset-specific contributions of γδ T cells to a well-established murine syngeneic model of ovarian cancer (ID8; transplantable cell line) that has a strong inflammatory component (23–25), akin to that observed in human patients with high-grade serous ovarian cancer (25, 26). In this murine model, we demonstrate that γδ T cells are major sources of IL-17, and both T cell receptor (TCR)δ-deficient and IL-17–deficient mice display reduced ID8 tumor growth. Interestingly, IL-17 production by γδ T cells in the tumor environment is essentially restricted to a CD27⁽⁻⁾ subset that does not express the commonly used Vγ1 or Vγ4 TCR chains, but rather Vγ6; these Vγ6⁽⁺⁾ cells are highly biased toward IL-17 production, in contrast to their IFN-γ–producing Vγ1⁽⁺⁾ and Vγ4⁽⁺⁾ counterparts. The ID8 tumor environment gets progressively enriched in the IL-17–promoting factor IL-7, whose receptor is highly expressed on Vγ6⁽⁺⁾ cells. This associates with preferential Vγ6⁽⁺⁾ cell proliferation and accumulation of IL-17 in the tumor bed, which in turn induces the mobilization of (recently described) small peritoneal macrophages (SPMs) that are enriched in IL-17 receptor A (IL-17RA) and in protumor and proangiogenic molecular mediators. Importantly, in comparison with large peritoneal macrophages (LPMs), SPMs can strongly and directly promote ovarian cancer cell proliferation. In summary, our work identifies an IL-17–dependent γδ T-cell/SPM axis that promotes tumor cell growth and thus opposes the widely accepted antitumor (and IFN-γ mediated) function of γδ T cells.     

Improving the Th1 cellular efficacy of the lead Yersinia pestis rF1-V subunit vaccine using SA-4-1BBL as a novel adjuvant

The lead candidate plague subunit vaccine is the recombinant fusion protein rF1-V adjuvanted with alum. While alum generates Th₂ regulated robust humoral responses, immune protection against Yersinia pestis has been shown to also involve Th₁ driven cellular responses. Therefore, the rF1-V-based subunit vaccine may benefit from an adjuvant system that generates a mixed Th₁ and humoral immune response. We herein assessed the efficacy of a novel SA-4-1BBL costimulatory molecule as a Th₁ adjuvant to improve cellular responses generated by the rF1-V vaccine. SA-4-1BBL as a single adjuvant had better efficacy than alum in generating CD4⁺ and CD8⁺ T cells producing TNFα and IFNγ, signature cytokines for Th₁ responses. The combination of SA-4-1BBL with alum further increased this Th₁ response as compared with the individual adjuvants. Analysis of the humoral response revealed that SA-4-1BBL as a single adjuvant did not generate a significant Ab response against rF1-V, and SA-4-1BBL in combination with alum did not improve Ab titers. However, the combined adjuvants significantly increased the ratio of Th₁ regulated IgG_2c in C57BL/6 mice to the Th₂ regulated IgG₁. Finally, a single vaccination with rF1-V adjuvanted with SA-4-1BBL + alum had better protective efficacy than vaccines containing individual adjuvants. Taken together, these results demonstrate that SA-4-1BBL improves the protective efficacy of the alum adjuvanted lead rF1-V subunit vaccine by generating a more balanced Th₁ cellular and humoral immune response. As such, this adjuvant platform may prove efficacious not only for the rF1-V vaccine but also against other infections that require both cellular and humoral immune responses for protection.     

The use of 7-amino actinomycin D in identifying apoptosis: simplicity of use and broad spectrum of application compared with other techniques

The detection and quantitation of apoptotic cells is becoming increasingly important in the investigation of the role of apoptosis in cellular proliferation and differentiation. The pathogenesis of hematologic disorders such as aplastic anemia and the development of neoplasia are believed to involve dysregulation of apoptosis. To quantitate accurately the proportion of apoptosis cells within different cell types of a heterogeneous cell population such as blood or bone marrow, a method is required that combines the analysis of large numbers of cells with concurrent immunophenotyping of cell surface antigens. In this study, we have evaluated such a method using the fluorescent DNA binding agent, 7-amino actinomycin D (7AAD), to stain three diverse human cell lines, induced to undergo apoptosis by three different stimuli. Flow cytometric analysis defines three populations on the basis of 7AAD fluorescence and forward light scatter. We have shown by cell sorting and subsequent morphological assessment and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling that the populations defined by 7AAD represent live, apoptotic, and late-apoptotic/dead cells. This method is quick, simple, reproducible, and cheap and will be a valuable tool in the investigation of the role of apoptosis in normal physiology and in disease states.     

Alcohol metabolism and fetal hypoplasia in chick brain

Chick embryos given a single dose of ethanol (1.0 g/kg) at the start of incubation (day 0) had widely differing levels of blood alcohol when sacrificed on day 7 and the blood alcohol levels were inversely correlated with whole body and brain weight. Clearance of the alcohol by the embryos was inhibited by simultaneous treatment with 4-methyl pyrazole and this treatment potentiated the brain growth inhibition due to ethanol. Treatment with indomethacin lowered blood alcohol levels on day 7 and protected against the growth inhibition. These data suggest that early chick embryos have varying amounts of alcohol dehydrogenase-like metabolic activity and that higher levels of this activity protect against alcohol-induced brain growth inhibition in this model. If similar variations in the ability to metabolize alcohol exist in human fetuses, it may represent a mechanism by which comparable maternal doses of alcohol produce widely varying fetal effects.     

The changing profile of the patient undergoing coronary artery bypass surgery

The first 100 consecutive patients undergoing isolated coronary artery bypass surgery in 1975 were evaluated with respect to the incidence of operative risk factors and outcome. When compared with an identically selected group from 1985, there was significant worsening of the preoperative condition over the decade with regard to mean age (p less than 0.0005), presence of congestive heart failure (p less than 0.05), left ventricular dysfunction (p less than 0.05), severity of coronary artery disease (p less than 0.001) and incidence of emergency operation (p less than 0.05). More patients in 1985 had associated medical diseases such as diabetes (p less than 0.01) and chronic lung disease (p less than 0.005). There was an increase in the occurrence of vascular diseases (hypertension, renal dysfunction, peripheral vascular and cerebrovascular disease) (p less than 0.05). Overall operative mortality increased from 1 to 8% (p less than 0.05) over the decade. Despite the deterioration in the clinical profile of the patient undergoing coronary bypass surgery, elective procedures were still performed with low mortality. The significant increase in overall mortality was chiefly in patients undergoing emergency operation (p less than 0.05). There were also increases in operative morbidity including low output syndrome (p less than 0.01) and respiratory (p less than 0.005) and neurologic (p = 0.06) complications.     

The role of podcast lectures in associate degree nursing programs

Associate degree nursing (ADN) programs are faced with the challenge of developing nursing students' critical thinking abilities and skills proficiency. This article discusses the potential role of podcasts as an innovative teaching strategy for nursing professors to implement principles of adult learning while developing the critical thinking skills of ADN students.