Immunomodulatory effects of H.P. Acthar Gel on B cell development in the NZB/W F1 mouse model of systemic lupus erythematosus.

H.P. Acthar Gel® (Acthar) is a highly purified repository gel preparation of adrenocorticotropic hormone (ACTH1-39), a melanocortin peptide that can bind and activate specific receptors expressed on a range of systemic lupus erythematosus (SLE)-relevant target cells and tissues. This study was performed to evaluate the effects of Acthar in a mouse model of SLE, using an F1 hybrid of the New Zealand Black and New Zealand White strains (NZB/W F1). Twenty-eight week old NZB/W F1 mice with established autoimmune disease were treated with Acthar, Placebo Gel (Placebo), or prednisolone and monitored for 19 weeks. Outcomes assessed included disease severity (severe proteinuria, ≥ 20% body weight loss, or prostration), measurement of serial serum autoantibody titers, terminal spleen immunophenotyping, and evaluation of renal histopathology. Acthar treatment was linked with evidence of altered B cell differentiation and development, manifested by a significant reduction in splenic B cell follicular and germinal center cells, and decreased levels of circulating total and anti-double-stranded DNA (IgM, IgG, and IgG2a) autoantibodies as compared with Placebo. Additionally, Acthar treatment resulted in a significant decrease of proteinuria, reduced renal lymphocyte infiltration, and attenuation of glomerular immune complex deposition. These data suggest that Acthar diminished pathogenic autoimmune responses in the spleen, peripheral blood, and kidney of NZB/W F1 mice. This is the first preclinical evidence demonstrating Acthar's potential immunomodulatory activity and efficacy in a murine model of systemic lupus erythematosus.

RIBP, a novel Rlk/Txk- and itk-binding adaptor protein that regulates T cell activation.

A novel T cell-specific adaptor protein, RIBP, was identified based on its ability to bind Rlk/Txk in a yeast two-hybrid screen of a mouse T cell lymphoma library. RIBP was also found to interact with a related member of the Tec family of tyrosine kinases, Itk. Expression of RIBP is restricted to T and natural killer cells and is upregulated substantially after T cell activation. RIBP-disrupted knockout mice displayed apparently normal T cell development. However, proliferation of RIBP-deficient T cells in response to T cell receptor (TCR)-mediated activation was significantly impaired. Furthermore, these activated T cells were defective in the production of interleukin (IL)-2 and interferon gamma, but not IL-4. These data suggest that RIBP plays an important role in TCR-mediated signal transduction pathways and that its binding to Itk and Rlk/Txk may regulate T cell differentiation.

West African HIV-2-related human retrovirus with attenuated cytopathicity.

Clinical and seroepidemiological studies in West Africa indicate that human immunodeficiency virus type 2 (HIV-2) is widespread and associated with immunodeficiency states of variable degree. In this study, an isolate of HIV-2 from a patient in Senegal was molecularly cloned and characterized. This isolate (HIV-2ST) was shown by hybridization and restriction enzyme analysis to be more related to the prototype HIV-2ROD than to other human or primate retroviruses. Cultures of HIV-2ST showed genotypic polymorphism, and clones of the virus had transmembrane envelope glycoproteins of 30 and 42 kilodaltons. Unlike other immunodeficiency viruses, HIV-2ST did not cause cell death or induce cell fusion in peripheral blood lymphocytes or in any of four CD4+ cell lines tested. Although HIV-2ST entered cells by a CD4-dependent mechanism and replicated actively, cell-free transmission of the virus was retarded at the level of cell entry. These findings suggest that immunodeficiency viruses prevalent in West African populations are members of the HIV-2 virus group and that certain strains of this virus have attenuated virulence.

[Port stapling for simplified port implantation in laparoscopic adjustable gastric banding]. / Port-Stapling zur Erleichterung der Portimplantation bei der laparoskopischen Magenbandoperation.

BACKGROUND: The purpose of this study was to evaluate the applicability of a port stapling device to simplify and improve port implantation in laparoscopic adjustable gastric banding (LAGB). METHODS: From November 2005 to September 2006, a prospective study was conducted on 23 consecutive patients who underwent LAGB with Swedish adjustable gastric banding. Patients were randomized to either conventional titanium-port implantation or port stapling using the "Velocity" device. RESULTS: No differences in age, body weight, body mass index, fascia depth or incision length were reported between the groups. Port implantation time was significantly less using port stapling (90+/-24 s) compared to conventional port implantation (521+/-138 s). Port related complaints postoperatively and at follow-up were equal in both groups. CONCLUSIONS: Port stapling is an excellent tool to facilitate port implantation, particularly in massively obese patients with a thick abdominal wall.

8-Styryl-substituted coralyne derivatives as DNA binding fluorescent probes.

Six new 8-styryl-substituted coralyne derivatives 4a-f were synthesized from coralyne (2) by a base catalysed Knoevenagel type reaction. It was shown by photometric and fluorimetric titrations of double stranded and quadruplex DNA to 4b-d as well as by fluorimetric DNA denaturation experiments that these ligands bind to DNA with different binding modes at varying ligand-DNA ratios (LDR). Specifically, the addition of DNA caused initially a hypochromic effect in absorbance and, at a particular LDR, the development of a new red shifted absorption band with a hyperchromic effect. Furthermore, 4b-d induced a significant and selective stabilization of quadruplex DNA towards unfolding (ΔTm = 31.6-32.9 °C at LDR = 5), which is even more pronounced as compared to the parent compound coralyne (2). Most notably, the addition of DNA to the dimethylamino-substituted derivative 4b leads to a new, strongly red-shifted emission band at 695 nm. Hence, this derivative is a fluorescent probe that changes its fluorescence colour from green to red in the presence of DNA and even allows the fluorimetric analysis of living cells by staining of the nucleoli.

Reduced liver apoptosis after venous systemic oxygen persufflation in non-heart-beating donors.

Graft injury caused by warm ischemia in livers from non-heart-beating donors (NHBDs) strongly affects posttransplantation outcome and is associated with liver apoptosis, which is mediated by death receptors, such as Fas, a surface receptor of the tumor necrosis factor (TNF)-alpha family. The aim of this study was to test the ability of venous systemic oxygen persufflation (VSOP) to reduce apoptotic changes and Fas activation in the liver after warm ischemic insult in vivo. Livers of male Wistar rats were harvested 30 min after cardiac arrest from non-heart-beating donors (NHBD) with (NHBD + O2) or without (NHBD) application of gaseous oxygen during the cold storage period via the suprahepatic caval vein. After 24 h of storage in University of Wisconsin solution at 4 degrees C, viability of the livers was assessed upon isolated reperfusion in vitro. Conventional signs of tissue damage like enzyme release and bile production showed a significantly elevated nonspecific cell injury in the NHBD group. TUNEL staining revealed increased DNA fragmentation of sinusoidal endothelial cells in the NHBD group and more apoptotic hepatocytes than in the control group. All these alterations could be almost abrogated by the use of VSOP in the NHBD + O2 group. The immunohistochemical staining of Fas antigen expression showed a significantly elevated Fas receptor expression in the NHBD and NHBD + O2 groups, in accord with an eightfold increase of Fas receptor mRNA detected by real-time reverse-transcription polymerase chain reaction (RT-PCR). These results demonstrate that the postischemic apoptotic rate of sinusoidal endothelial cells in NHBD livers can be reduced by the use of VSOP. A significant improvement in liver integrity and viability was obtained with this technique, without influencing the expression of Fas expression.

Phase II evaluation of cytembena (NSC-104801) in patients with advanced ovarian carcinoma resistant to alkylating agents: brief communication.

Seventeen patients with stages III and IV alkylating agent-resistant ovarian carcinomas were treated with cytembena, which was given in doses of 200 mg/m2 twice daily for 5 consecutive days every 5 weeks. Sixteen patients completed at least one course of treatment; 11 of them experienced objective progression of disease or failed to continue treatment because of a continuing symptomatic deterioration within the first two treatment cycles. Three patients remained objectively stable after two courses of treatment, but were symptomatically worse and stopped treatment for that reason. Another patient experienced progression after three courses, and the final patient voluntarily withdrew after three courses. No objective regression of disease occurred during treatment with cytembena. Nausea and vomiting occurred at some time in all except 1 patient, and 3 patients experienced mild diarrhea. Two patients had alopecia.

Use of tamoxifen for breast cancer: twenty-eight years later.

PURPOSE: The mechanisms of antitumor activity, clinical pharmacology, toxicity, and efficacy of tamoxifen in women with early and advanced breast cancer and the drug's potential role in prevention of breast cancer were reviewed. DESIGN: A comprehensive review of the literature from 1966 to 1994 was conducted; reports were identified using the Cancerline and Medline data bases. RESULTS: The cellular actions of tamoxifen are not completely understood, but it appears that the drug's antiproliferative effects are mediated primarily by inhibition of the activities of estrogen through binding to estrogen receptors (ERs). Disease-free and overall survival rates have been increased in postmenopausal women with ER-positive tumors when tamoxifen has been used as adjuvant therapy (irrespective of nodal status). In premenopausal women, adjuvant therapy with tamoxifen has been associated with prolongation of disease-free survival, but its impact on survival remains to be defined. Tamoxifen is the initial hormonal treatment of choice in both premenopausal and postmenopausal women with ER-positive metastatic disease. Retrospective review of adjuvant therapy studies showed an approximately 39% reduction in the incidence of contralateral primary breast carcinoma in tamoxifen-treated women, which indicates that tamoxifen could have a role in breast cancer prevention. CONCLUSION: The use of tamoxifen has resulted in a substantial modification of breast cancer's natural history, particularly in postmenopausal women. Ongoing clinical trials will examine the effects of tamoxifen therapy on lipids, coagulation proteins, bone, and endometrium, and its effectiveness as an agent in the prevention of breast cancer.

Brain metastases in patients with renal cell carcinoma: prognosis and treatment.

Thirty-four patients with renal cell carcinoma and brain metastases were reviewed to define important prognostic factors and treatment results. The following covariates were analyzed to determine their influence on survival: disease-free interval, serum calcium, number of central nervous system (CNS) metastases, weight loss, performance score, age, radiation therapy, surgery, and surgery plus radiation. The mean survival for all patients was 7.0 months (range, seven days to 32 months). The patients with a good performance score of 0-2 survived significantly longer (mean survival, 10.2 months) than those with a poor performance score of 3-4 (mean survival, 2.8 months; p = 0.0019). Surgery was associated with significantly improved survival (mean survival, 13.8 months versus mean survival, 4.2 months; p = 0.014). However, all the surgical patients were from the good performance score group, suggesting patient selection. Radiation was associated with an improved mean survival of 8.6 months versus 3.2 months. Performance score is a significant prognostic factor. Furthermore, the data support treatment with radiation therapy for patients with multiple CNS metastases and surgery followed by postoperative radiation therapy for patients with single CNS metastases.

A phase II study of recombinant alpha interferon in patients with recurrent or metastatic breast cancer.

Thirty-three patients with advanced breast cancer were treated with a recombinant alpha interferon (rIFN-alpha 2). All patients were ambulatory (performance status greater than or equal to 50 Karnofsky scale) and almost all had received previous chemotherapy. Large intravenous dosages of 30 to 50 X 10(6) IU/m2 were given for five consecutive days every two to three weeks to 22 patients and smaller subcutaneous dosage of 2 X 10(6) IU/m2 three times a week to 11 patients. No complete or partial responses were seen. Two patients had stable disease and the remainder progressed. Flu-like syndromes were seen in all patients. Nausea, vomiting, and anorexia were frequent. Hypotension and confusion were noted in six and five patients, respectively. Life-threatening leukopenia was noted in two patients receiving intravenous dosage and thrombocytopenia was noted in one; no sepsis or bleeding complications were noted. In this study, a highly purified and biologically active rIFN-alpha 2 was not associated with activity in previously treated women with metastatic breast cancer.

Localization of damage induced by reactive oxygen species in cultured cells.

N18-RE-105 neuron-derived hybridoma cells were employed to determine the location and degree of damage induced by each of three reactive oxygen species (ROS) generators: 6-hydroxydopamine (6-OHDA), H2O2, and cumene hydroperoxide. Two readily distinguishable plasma membrane markers were used to assess cell surface damage, namely the active transport of alpha-aminoisobutyric acid (AIB) and the facilitated diffusion of glucose. In addition, staining of mitochondria with a tetrazolium dye, 3[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT), was used as an intracellular marker to measure the integrity of the metabolic function of the mitochondria. The dose-response curve of inactivation of transport or of metabolic function varied with the ROS generator used and conformed to one of two patterns of toxicity: either threshold-dependent or single-hit inactivation. We determined that 6-OHDA acts simultaneously on multiple targets and steps in the cells, resulting in a very steep dose-effect curve. Similarly, damage induced by H2O2 to the AIB transporters and to mitochondria is consistent with simultaneous inactivation of multiple steps, but damage to glucose transporters conforms to single-hit inactivation of the transporter. Conversely, treatment with cumene hydroperoxide resulted in single-hit inactivation of the AIB transporter, but inactivation of the glucose transporter conformed to threshold-dependent inactivation. Thus, to evaluate quantitatively damage produced by ROS at the subcellular level, both the type of toxic agent and the target to be evaluated must be considered. Finally, the inactivation of each of the targets observed in this study for all of the ROS generators used conform to one of two simple inactivation models. Fitting the appropriate model to the data allows precise quantitative analysis of the inactivation process and provides insight into the chemistry of the inactivation process.

Efficacy of lipid soluble, membrane-protective agents against hydrogen peroxide cytotoxicity in cardiac myocytes.

We examined the efficacy of a group of drugs that stabilize the cell membrane and can potentially prevent cytotoxicity in cultured fetal chick cardiac myocytes exposed to hydrogen peroxide (H2O2). The effects of various membrane-protective agents were determined by analysis of the kinetics of lactic dehydrogenase (LDH) release. The kinetic parameters calculated from the data include a rate constant for release of LDH (kb) and the fraction of total LDH that is released from the cells (CIIMax). The CIIMaxs derived from a range of H2O2 concentrations reveal that the mean toxic concentration of H2O2 is 1.1 mM and that the pattern of toxicity is consistent with the damage being directly proportional to the concentration of the free radicals generated from the H2O2. Maximum nontoxic concentrations of three amphiphilic membrane protective agents had no effect upon cytotoxicity from H2O2. The slightly polar lipophilic agent, Trolox C, a vitamin E derivative, was also without protective effect at a maximum nontoxic concentration. The highly lipophilic agent, probucol, had a small protective effect at 50 microM, the maximum concentration we succeeded in solubilizing in the culture medium. However, the lipophilic 21-aminosteroid U74500, delivered to the cells in an emulsion, markedly reduced cytotoxicity from H2O2. The CII Max was significantly reduced and the protection was concentration dependent over a range of concentrations from 50-400 nmol/ml. Furthermore, the inhibition by U74500 was fully consistent with a mechanism of scavenging of free radicals formed during lipid peroxidation. In support of this hypothesis, a dose of 400 nmoles/ml completely prevented an increase in lipid peroxides due to H2O2 exposure, whereas there was a sixfold increase during exposure to H2O2 in untreated myocytes. Thus, a lipid soluble 21-aminosteroid prevented lipid peroxidation and reduced cardiac myocyte injury during exposure to H2O2, probably by scavenging of free radicals formed during lipid peroxidation in the cell membrane, whereas amphiphilic agents, which probably altered the physicochemical structure of the cell membrane but did not scavenge free radicals, were not protective.

Cytometrically coherent transfer of receptor proteins on microporous membranes.

A new method (Freeze-Transfer) is described for performing high-resolution immunocytochemistry for soluble cell proteins on frozen sections of biological tissues that involves thaw-mounting frozen tissue sections directly onto the surface of nitrocellulose thin films instead of directly onto glass slides. This technically straight-forward change in methodology resulted in chromogenic immunocytochemical assays for Her-2 and EGF receptors that were 1-2 orders of magnitude more sensitive while still fully utilizing the diagnostic resolving power of light microscopy. The effects of membrane pore size and surface chemistry on the resolution and intensity of Her-2 signal suggest that the enhanced sensitivity of Freeze-Transfer was caused by the cytologically coherent transfer of target molecules normally lost from cut surfaces of cells mounted on nonporous glass during assay.

Interrelating B cell subpopulations and environmental regulation with the expression of three tiers of repertoire diversity.

The B cell repertoire consists of three tiers of clonotype diversity. One tier, which is the product of H chain V region rearrangements in the absence of N additions, is of limited diversity (less than 10(8) clonotypes) so that clonotypes of this tier would be expected to recur within and among B cells of individuals of an inbred strain. These clonotypes, therefore, could be subjected to, and conserved by, evolutionary selective pressures such as those imposed by ubiquitous bacterial pathogens. The second tier of clonotypes is created by H chain V region rearrangements that include N additions, and is, therefore, exceedingly diverse. Clonotypes of this tier would be unlikely to recur; however, by providing maximal diversity they would ensure protection against a wide spectrum of pathogens. The third tier of diversity is that which is generated by the superimposition of somatic mutations on clonotypes of the other two tiers. This tier of clonotypes is reflective of the refinement of specificities that are destined for expression in memory B cells. B cells exists as three distinct subpopulations, Ly-1 B cells, conventional primary B cells and memory B cells. These subpopulations differ functionally, developmentally, and by the extent to which they are impacted by immunoregulatory processes. Furthermore, B cells of these subpopulations differentially express the three tiers of clonotype diversity.

Inhibition of oxidative insult in cultured cells by a novel 6-chromanol-containing antioxidant.

N18-RE-105 neuronal hybridoma cells were used in a cell culture system to evaluate the protective effects of a novel 6-chromanol-containing antioxidant, U78517F. First, the incorporation of the compound into the cells was evaluated, using a serum albumin carrier. Then the cells were exposed to peroxide-generating compounds, and the cell injury was estimated from the loss of alpha-aminoisobutyric acid (AIB) transport. We found that U78517F only protected the cells significantly when the degree of oxidative insult was below a certain limit; the measurable protection of cells by U78517F against either cumene hydroperoxide or H2O2 was limited to a narrow range of concentrations of the reactive oxygen species generator. Additionally, the protection provided by U78517F was largely localized to the cell membrane and did not extend to protection of mitochondrial function. The action of U78517 was fully consistent with a direct radical scavenging in the cells. The results indicate that the following factors must be taken into account for evaluation of antioxidants in cell culture: (a) the delivery of a compound to cells, especially when the compound is lipophilic; (b) the nature and extent of the oxidative insult used to evaluate protection; and (c) the location of the protective agent in the cells.

Myelodysplastic syndrome at a large tertiary care community hospital: analysis according to the international prognostic scoring system.

The outcome of patients diagnosed myelodysplastic syndromes (MDS) between 1990 and 1997 from William Beaumont Hospital (WBH) was analyzed according to the International Prognostic Scoring System (IPSS) risk categorization. A retrospective study of 195 MDS patients wa s performed. Seventy-nine patients with MDS, in whom a karyotype was obtained and with an adequate follow-up were included in the final analysis. Cases of proliferative CMML (WBC > 12x10(9)/l) were excluded from the study. The overall median survival was 3.1 years, and median survival stratified by IPSS was 3.4, 4.1 and 0.5 years for the INT-1, INT-2 and high risk group and not yet reached for the low risk group. The overall survival by IPSS subcategorization were 6.88, 5.29, 5.30 and 2.12 years for the low, INT-1, INT-2, and high risk groups respectively. Cytogenetics were significant in predicting the overall survival. The IPSS score stratified patients into risk categories for development of AML. The risk of development into AML was 8, 8, 33 and 54% for the low, INT-1, INT-2 and high risk groups, respectively. We conclude that IPSS score can be useful in predicting survival and AML evolution in some MDS patients.

Automated sputum screening with PAPNET system: a study of 122 cases.

The use of interactive, computerized PAPNET system (Neuromedical Systems, Inc, Suffern, NY) for screening of cervicovaginal smears has been favorably evaluated in several studies. In this article, the authors report on the performance of this apparatus on smears of sputum. One hundred twenty-two randomly selected, single slides of sputum specimens from an equal number of patients were subjected to PAPNET scanning. These Papanicolaou-stained slides were previously classified as inadequate, six; negative, 81; atypical, three; suspicious, one; and positive for malignant cells, 31. Images selected by PAPNET were reviewed by two observers, who were blinded to earlier interpretation and triaged into two categories: negative and review. Of the 31 smears with cancer cells, 30 were appropriately identified by PAPNET (sensitivity: 97.1%). The only case missed by PAPNET was that of small cell carcinoma that contained a single cluster of neoplastic cells. PAPNET also triggered the review of 20 of the "negative" cases, which on re-evaluation were identified as bronchial cells with squamous metaplasia and altered benign squamous cells of inflammatory type. A prospective study of PAPNET for screening of sputum samples is needed to establish the clinical value of this methodology.

The significance of a cytologically negative pleural effusion in bronchogenic carcinoma.

Bronchogenic carcinoma complicated by ipsilateral cytologically positive effusion is considered unresectable. Bronchogenic carcinoma with cytologically negative effusion, even if bloody, has also been thought by many to be unresectable. Seventy-three patients with bronchogenic carcinoma and ipsilateral cytologically negative effusions were studied. Sixty-six underwent exploratory thoracotomy for staging or therapy; five had pleural biopsies and two had mediastinoscopies, all disclosing metastatic carcinoma. Four of the 73 patients (5.5 percent) had surgically resectable disease. They have remained free of disease for 3, 6, 7, and 14 years. Sixty-nine patients (94.5 percent) had unresectable carcinoma with metastases. Seventeen (94 percent) of 18 patients with bloody effusions had unresectable cancer. Carcinoma was resected in one patient with cytologically negative bloody effusion, and the patient remained free of disease during the 14-year follow-up period. Unresectability must be documented surgically in these patients to exclude those in whom curative resection can be performed.

Surgical stress induces a shift in the type-1/type-2 T-helper cell balance, suggesting down-regulation of cell-mediated and up-regulation of antibody-mediated immunity commensurate to the trauma.

BACKGROUND: Measuring serum cytokines, pituitary hormones, or acute phase proteins during or after surgery is not an optimal method for quantifying the impact of surgical procedures. In an effort to assess surgical stress by means of the immune response, we focused on changes in cell-mediated and antibody-mediated immunity as illustrated by the type 1/type 2 T-helper (Th1/Th2) cell balance. The sensitivity of this approach was evaluated by comparing laparoscopic and conventional cholecystectomy (LCE, CCE). METHODS: In a pragmatic prospective study 43 patients with symptomatic cholelithiasis were operated on either by LCE (n = 25) or CCe (n = 18). Blood sampling was done 24 hours before surgery, immediately before incision, and 2, 24, and 48 hours after surgery. Cell surface markers and cytokine production were used to characterize the Th1/Th2 balance and were measured by means of flow cytometry and enzyme-linked immunosorbent assay techniques. RESULTS: Activation of Th2 cells evokes the production and secretion of interleukin-4 (IL-4), which up-regulates the expression of immunoglobulin E receptors (Fo epsilon RII, CD23) on B cells. Phytohemagglutinin-induced IL-4 production in freshly isolated peripheral blood mononuclear cells from patients increased more after CCE than LCE (IL-4, +41% versus +17%; p < 0.05). Also the expression of CD23 on B cells was higher after CCE than LCE (+146% versus +63%; P < 0.01). CD30, a membrane molecule that belongs to the tumor necrosis factor receptor superfamily and probably is an important indicator of Th2 activity, was more evaluated on T cells from patients who underwent CCE. The Th1 response, characterized by phytohemagglutinin-induced IFN-gamma secretion in peripheral blood mononuclear cells and up-regulation of human leukocyte antigen-DR expression on monocytes, was lower after CCE than after LCE. CONCLUSIONS: This study shows that surgical stress induces a shift in the Th1/Th2 balance toward Th2, suggesting that cell-mediated immunity is down-regulated and antibody-mediated immunity is up-regulated after surgery. The evaluation of this shift may be clinically meaningful and help quantify even less invasive surgical procedures. When comparing CCE and LCE in this not strictly randomized study, we found LCE to be the less stressful procedure.

Cancer metastatic to the ovary: factors influencing survival.

In the period 1950 through 1966, 357 patients with cancer metastatic to the ovaries were treated at the Mayo Clinic. The majority of primary tumors arose in the gastrointestinal tract. Factors influencing survival included the site of the primary cancer, histologic grade of the neoplasm, menstrual status, and the type of treatment. Patients whose cancers originated in the genital tract had the lowest mean death rate. Although analyses of survival confirm the observation that cancer metastatic to the ovaries has a poor overall prognosis, 21 of the 357 patients were still living at 10 years and 7 of these patients survived for at least 20 years. The continued development of improved technics of radiation therapy and of more effective chemotherapeutic agents should facilitate intensive therapy for patients with metastatic cancer of the ovaries and result in improved survival.