Acetyl-11-keto-beta-boswellic acid induces apoptosis in HL-60 and CCRF-CEM cells and inhibits topoisomerase I.

Antiproliferative action of different pentacyclic triterpenes has repeatedly been reported, and some lipoxygenase inhibitors have been shown to induce cell death in various cell systems. Acetyl-11-keto-beta-boswellic acid (AKBA) is a pentacyclic triterpene that inhibits 5-lipoxygenase in a selective, enzymedirected, nonredox, and noncompetitive manner. To investigate a possible effect of AKBA on leukemic cell growth, proliferation of HL-60 and CCRF-CEM cells was assayed in the presence of AKBA and a structural analog without effect on 5-lipoxygenase, amyrin. Cell counts and [3H]thymidine incorporation were significantly reduced in a dose-dependent manner in the presence of AKBA (IC50 = 30 microM) but not amyrin. An additive effect of AKBA with the crosslinking of the CD95 receptor was also observed. Flow cytometric analysis of propidium iodide-stained cells indicated that the cells underwent apoptosis. This was confirmed by flow cytometric detection of sub-G1 peaks in AKBA-treated cells and by DNA laddering. However, because HL-60 and CCRF-CEM do not express 5-lipoxygenase mRNA constitutively, a mechanism distinct from inhibition of 5-lipoxygenase must account for the effect of AKBA. In a DNA relaxation assay with phiX174RF DNA, AKBA inhibited topoisomerase I from calf thymus at concentrations of >/=10 microM. A semiquantitative cDNA polymerase chain reaction approach was used to estimate the relative level of expression of topoisomerases in both cell lines. The data suggest that induction of apoptosis in HL-60 and CCRF-CEM by AKBA may be due to inhibition of topoisomerase I in these cells.

Activation-dependent expression of the insulin-like growth factor binding protein-2 in human lymphocytes.

The expression of the insulin-like growth factor binding protein-2 (IGFBP-2) was assayed in mononuclear cells originating from different organs of the immune system. All mononuclear cells studied did express IGFBP-2, but the expression level was found to be dependent on the cell type and origin of the cell. T cells showed a higher expression of IGFBP-2 mRNA than did B cells, and CD34+ stem cells expressed IGFBP-2 mRNA at a high level. Expression was highest in bone marrow and thymus. Stimulation of peripheral mononuclear cells resulted in a marked increase of IGFBP-2 mRNA and also intracellular IGFBP-2, as analysed by fluorescence staining. This increase parallels the increase of other known T-cell activation markers. Furthermore, the increase of intracellular IGFBP-2 seems to precede T-cell blast formation and all T cells in active phases of the cell cycle have high levels of IGFBP-2. Our results provide a basis for further investigations on the contribution of the IGF-system to the regulation of T-cell proliferation and differentiation. IGFBP-2, in particular, may have an important influence in the regulation of T-cell activation and proliferation.

T-cell stimulation and cytokine release induced by staphylococcal enterotoxin A (SEA) and the SEAD227A mutant.

Previous work demonstrated that human cytotoxic T cells activated by superantigens can lyse major histocompatibility complex (MHC) class II-positive target cells as well as MHC class II-negative tumour cells coated with conjugates of monoclonal antibodies and superantigens. In order to decrease MHC class II affinity, and therefore unwanted binding of the superantigen staphylococcal enterotoxin A (SEA) to MHC class II molecules, a point mutation was introduced into the SEA gene. This mutation (SEAD227A) resulted in an approximately 3-log reduction of affinity to human leucocyte antigen (HLA)-DR, but cytotoxicity mediated by this mutant superantigen towards antibody-labelled tumour cells is as efficient as cytotoxicity mediated by the native superantigen. We therefore compared the T-cell activating potency of native and mutated SEA. Our data show that SEAD227A is 4- to 5-log less effective than native SEA when activation of resting T cells is assayed in terms of blast formation, expression of cell surface activation markers and cytokine release. Furthermore, presenting either SEA or SEAD227A to MHC class II-negative mononuclear cells by MHC class II-negative tumour cells did not result in significant blast formation of T cells, up-regulation of CD25 or cytokine release. This suggests that lysis of MHC class II-negative tumour cells is efficiently induced by monoclonal antibody targeted superantigen, while activation of resting T cells requires additional co-stimulatory signals.

Superantigen-mediated cellular cytotoxicity is dependent on antigen expression, but independent of the P-glycoprotein multidrug resistance phenotype.

Superantigen-activated T cells can be targeted by monoclonal antibodies (mAb) to lyse MHC class II negative tumour cells. In this study we determined the susceptibility of the T-lymphoblastoid leukaemic cell line CCRF-CEM and its multidrug resistant sublines CCRF VCR100, CCRF VCR1000 and CCRF ADR5000 to lysis by monoclonal antibody-targeted and superantigen-activated T cells (superantigen-dependent cellular cytotoxicity, SDCC). A recombinant fusion protein of protein A and the superantigen Staphylococcus enterotoxin A (SEA) was used together with the mAbs anti-CD7, anti-CD38, anti-CD45RA and 4E3 (anti-P-glycoprotein) to correlate susceptibility to SDCC with expression of the MDR1-gene product. Our results demonstrated SDCC to be independent of MDR1-gene expression. This was further confirmed by blocking the function of Pgp in the leukaemic cell lines with a cyclosporine A derivative, which had no influence on SDCC. As expected, expression of the respective cell surface antigens on target cells had a strong impact on SDCC, although other factors seem to influence efficiency of SDCC as well.

Patient perceptions of benefits and concerns following pancreas transplantation.

The purpose of this study was to assess patient perceptions of the impact of pancreas transplantation on various aspects of life, as well as perceptions of the benefits of and concerns with the procedure. All surviving adult patients who had received a pancreas transplant at a midwestern hospital and were at least 1 year posttransplant at the time of the study (N = 138) were sent a self-report questionnaire that included demographic data, questions about life satisfaction, quality of life, symptoms, and health impact. Patients with pancreas graft function reported less pain with healthcare treatment, fewer episodes of feeling physically ill, fewer dietary restrictions, less interference with family life, fewer health limitations in interpersonal relationships and leisure activities, and feeling good about themselves compared with those without graft function. A majority of patients with functioning grafts cited the following benefits: freedom from insulin reactions, normal blood sugars, freedom from insulin injections, freedom from a specialized diet, decreased chance of amputation, feeling better physically, more feelings of hope for the future, and more freedom and control over life. Major concerns posttransplant included side effects and the expense of immunosuppressive medications.

Comparison of a needleless system with conventional heparin locks.

BACKGROUND: Despite the improvements in needle disposal systems, needlesticks to health care workers continue to occur at unacceptably high rates. Needleless systems have been shown to reduce the risk of needlesticks. METHODS: This pilot study examined the safety of such a system for patients by comparing the rates of intravenous infection-related indicators between a conventional heparin lock and a needleless system. Patients (n = 97) were categorized on the basis of the duration of intravenous placement into 24-, 48-, and 72-hour groups. Within each group, half of the patients received conventional heparin locks and half received the needleless system. Intravenous infection-related indicators included catheter tip culture, adaptor fluid culture, intravenous site erythema, induration and tenderness, and elevated oral temperature. RESULTS: Prevalence of one or more indicators was 48% for the conventional and 40% for the needleless system, a difference that was not statistically significant. CONCLUSIONS: The needleless system appeared to pose no greater risk of infection to patients and nurses preferred it for its reduced risk of potential needlesticks.

Health-related quality of life outcomes of pancreas transplant recipients.

The health status and quality of life outcomes of 131 patients who were 1 to 11 years post-pancreas transplant were studied. Patients were compared based on the current status of their pancreas graft, i.e. whether or not their grafts were successful in maintaining an insulin-independent state, and according to recipient category (pancreas alone vs kidney and pancreas). For this study, quality of life was defined as patients' perceptions of their well-being and ability to function in six areas: physical and mental health, social functioning, role (work and home) functioning, overall health perceptions, and physical pain. Patient self-report questions from the Medical Outcome Study were used to provide a score scaled from 0 to 100, for each area. Health status was assessed by sick days, hospitalizations, and emergency room visits. Patients with a successful pancreas graft (N = 65) reported significantly more positive health perceptions (51.9 vs 28.9), less pain (33.9 vs 45.3), and greater ability to function socially (84.9 vs 71.3) than did patients whose pancreas grafts were not successful. In addition, patients with successful pancreas grafts rated their ability to perform routine activities as nearer to normal on the Karnofsky Index (2.82 vs 3.63) and were more likely to view themselves as healthier since the pancreas transplant than were patients whose pancreas grafts were not successful. These effects persisted after statistical adjustment for recipient category and case-mix factors of age, sex, education, and length of time since pancreas transplant.(ABSTRACT TRUNCATED AT 250 WORDS)

Quality of life of pancreas transplant recipients.

The quality of life outcome of 131 pancreas transplant recipients who were 1 to 11 years post-transplant were studied. Patients with a functioning pancreas graft (n = 65) described their current quality of life and rated their health significantly more favourably than those with non-functioning grafts (n = 66). For example, of those patients with a functioning pancreas graft, 68% expressed overall satisfaction with their life, 89% felt healthier since their transplant, and 78% reported that they could care for themselves and their routine daily activities. In contrast, of those patients without a functioning graft, only 48% expressed overall satisfaction with life (p less than 0.01), only 25% felt healthier since their transplant (p less than 0.001), and only 56% indicated they could care for themselves and their daily activities (p less than 0.001). Regardless of graft function, the majority of patients were comfortable with their decision to have the transplant, and most of the patients with pancreas graft function reported that they would have another transplant if their graft failed. While successful pancreas transplantation may not elevate all diabetic patients to the level of health and function of the general population, these patients report a significantly better quality of life than do those patients who remain diabetic.

Reducing blood glucose variability by use of abdominal insulin injection sites.

Virtually all patients with type I diabetes are familiar with inexplicable fluctuations in blood glucose concentration that expose them to both hypoglycemia and hyperglycemia. It is commonly assumed that such fluctuations are due, in large part, to variations in food intake, physical activities, and emotional state. However, substantial day-to-day variation in blood glucose concentration is observed when diet, exercise, emotional state, insulin dosage, and timing of insulin administration are held constant. This suggests that variation in the rate of absorption of insulin from the subcutaneous injection sites may be an important factor causing those fluctuations. Variations in insulin absorption are increased if the anatomic regions used for injections are rotated. A recent study completed at the University of Minnesota Hospital and Clinic indicates that it is inadvisable for type I diabetic subjects to rotate insulin injection regions; rather, insulin injections should be confined to a single anatomic region (usually the abdomen) as this will decrease day-to-day variability in blood glucose concentration. Such a decrease should allow greater precision in adjusting insulin doses, thereby helping achieve good control.