Comparisons of high versus low emergency department utilizers in sickle cell disease

STUDY OBJECTIVE

Patients with sickle cell disease often receive a substantial amount of their health care in the emergency department (ED) and some come to the ED frequently, seeking treatment for pain. As a result, patients with sickle cell disease are often stigmatized as opioid-seeking ED overutilizers. We describe the proportion of sickle cell disease patients who are high utilizers of the ED and compare them with other sickle cell disease patients on demographics, pain characteristics, health data, psychosocial characteristics, and quality of life.

METHODS

Two hundred thirty-two patients completed baseline data and at least 30 days of daily diary data. Baseline data included demographics, health data, and quality of life (Medical Outcome Study 36 Item Short Form). Daily diary data included ED utilization for sickle cell pain and descriptors of pain and distress.

RESULTS

Eighty-two (35.5%) patients were found to be high ED utilizers. Clinically important and statistically significant differences were found between high ED utilizers and all other sickle cell disease patients: lower hematocrit level, more transfusions, more pain days, more pain crises, higher mean pain and distress, and worse quality of life on Medical Outcome Study 36 Item Short Form physical function summary scales. After controlling for severity and frequency of pain, high ED utilizers did not use opioids more frequently than other sickle cell disease patients.

CONCLUSION

A substantial minority of sickle cell disease patients are high ED utilizers. However, high ED utilizers with sickle cell disease are more severely ill as measured by laboratory variables, have more pain, more distress, and have a lower quality of life.

Vorinostat and sorafenib synergistically kill tumor cells via FLIP suppression and CD95 activation

PURPOSE AND DESIGN

Mechanism(s) by which the multikinase inhibitor sorafenib and the histone deacetylase inhibitor vorinostat interact to kill hepatic, renal, and pancreatic adenocarcinoma cells has been defined.

RESULTS

Low doses of sorafenib and vorinostat interacted in vitro in a synergistic fashion to kill hepatic, renal, and pancreatic adenocarcinoma cells in multiple short-term viability (24-96 h) and in long-term colony formation assays. Cell killing was suppressed by inhibition of cathepsin proteases and caspase-8 and, to a lesser extent, by inhibition of caspase-9. Twenty-four hours after exposure, the activities of extracellular signal-regulated kinase 1/2, AKT, and nuclear factor-kappaB were only modestly modulated by sorafenib and vorinostat treatment. However, 24 h after exposure, sorafenib- and vorinostat-treated cells exhibited markedly diminished expression of c-FLIP-s, full-length BID, BCL-2, BCL-XL, MCL-1, XIAP, increased expression of BIM, and increased activation of BAX, BAK, and BAD. Expression of eIF2alpha S51A blocked sorafenib- and vorinostat-induced suppression of c-FLIP-s levels and overexpression of c-FLIP-s abolished lethality. Sorafenib and vorinostat treatment increased surface levels of CD95 and CD95 association with caspase-8. Knockdown of CD95 or FADD expression significantly reduced sorafenib/vorinostat-mediated lethality.

CONCLUSIONS

These data show that combined exposure of epithelial tumor cell types to sorafenib and vorinostat diminishes expression of multiple antiapoptotic proteins and promotes activation of the CD95 extrinsic apoptotic and the lysosomal protease pathways, and that suppression of c-FLIP-s expression represents a critical event in transduction of the proapoptotic signals from CD95 to promote mitochondrial dysfunction and death.

Transient exposure of carcinoma cells to RAS/MEK inhibitors and UCN-01 causes cell death in vitro and in vivo

The present studies were initiated to determine in greater molecular detail how MEK1/2 inhibitors [PD184352 and AZD6244 (ARRY-142886)] interact with UCN-01 (7-hydroxystaurosporine) to kill mammary carcinoma cells in vitro and radiosensitize mammary tumors in vitro and in vivo and whether farnesyl transferase inhibitors interact with UCN-01 to kill mammary carcinoma cells in vitro and in vivo. Expression of constitutively activated MEK1 EE or molecular suppression of JNK and p38 pathway signaling blocked MEK1/2 inhibitor and UCN-01 lethality, effects dependent on the expression of BAX, BAK, and, to a lesser extent, BIM and BID. In vitro colony formation studies showed that UCN-01 interacted synergistically with the MEK1/2 inhibitors PD184352 or AZD6244 and the farnesyl transferase inhibitors FTI277 and R115,777 to kill human mammary carcinoma cells. Athymic mice carrying approximately 100 mm(3) MDA-MB-231 cell tumors were subjected to a 2-day exposure of either vehicle, R115,777 (100 mg/kg), the MEK1/2 inhibitor PD184352 (25 mg/kg), UCN-01 (0.2 mg/kg), or either of the drugs in combination with UCN-01. Transient exposure of tumors to R115,777, PD184352, or UCN-01 did not significantly alter tumor growth rate or the mean tumor volume in vivo approximately 15 to 30 days after drug administration. In contrast, combined treatment with R115,777 and UCN-01 or with PD184352 and UCN-01 significantly reduced tumor growth. Tumor cells isolated after combined drug exposure exhibited a significantly greater reduction in plating efficiency using ex vivo colony formation assays than tumor cells that were exposed to either drug individually. Irradiation of mammary tumors after drug treatment, but not before or during treatment, significantly enhanced the lethal effects of UCN-01 and MEK1/2 inhibitor treatment. These findings argue that UCN-01 and multiple inhibitors of the RAS-MEK pathway have the potential to suppress mammary tumor growth, and to interact with radiation, in vitro and in vivo.

Breathing pattern, CO2 elimination and the absence of exhaled NO in freely diving Weddell seals

Weddell seals undergo lung collapse during dives below 50 m depth. In order to explore the physiological mechanisms contributing to restoring lung volume and gas exchange after surfacing, we studied ventilatory parameters in three Weddell seals between dives from an isolated ice hole on McMurdo Sound, Antarctica.

METHODS

Lung volumes and CO(2) elimination were investigated using a pneumotachograph, infrared gas analysis, and nitrogen washout. Thoracic circumference was determined with a strain gauge. Exhaled nitric oxide was measured using chemiluminescence.

RESULTS

Breathing of Weddell seals was characterized by an apneustic pattern with end-inspiratory pauses with functional residual capacity at the end of inspiration. Respiratory flow rate and tidal volume peaked within the first 3 min after surfacing. Lung volume reductions before and increases after diving were approximately 20% of the lung volume at rest. Thoracic circumference changed by less than 2% during diving. The excess CO(2) eliminated after dives correlated closely with the duration of the preceding dive. Nitric oxide was not present in the expired gas.

CONCLUSION

Our data suggest that most of the changes in lung volume during diving result from compression and decompression of the gas remaining in the respiratory tract. Cranial shifts of the diaphragm and translocation of blood into the thorax rather than a reduction of thoracic circumference appear to compensate for lung collapse. The time to normalise gas exchange after surfacing was mainly determined by the accumulation of CO(2) during the dive. These findings underline the remarkable adaptations of the Weddell seal for restoring lung volume and gas exchange after diving.

Risk of gastrointestinal disease associated with exposure to pathogens in the sediments of the Lower Passaic River

High levels of pathogenic microorganisms have been documented previously in waters of the Lower Passaic River in northern New Jersey. The purpose of this study was to characterize the microbial contamination of river sediments near combined sewer overflows (CSOs), a known source of pathogens. Concentrations of fecal coliform, total coliform, fecal Streptococcus, fecal Enterococcus, Pseudomonas aeruginosa, Staphylococcus aureus, Giardia lamblia, and Cryptosporidium parvum organisms were measured in 16 samples from three mudflat locations along the Lower Passaic River, as well as from an upstream location. Selected samples were also analyzed for antibiotic resistance. All of the samples contained high concentrations of total coliform, fecal coliform, fecal Streptococcus, and fecal Enterococcus organisms. Analysis of isolates of Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli from several samples indicated that each strain was resistant to at least one antibiotic typically used in clinical settings. Eight of 16 samples contained Giardia, and one sample contained Cryptosporidium. With these sampling data, a quantitative microbial risk assessment was conducted to evaluate the probability of infection or illness resulting from incidental ingestion of contaminated sediments over a 1-year period. Three potential exposure scenarios were considered: visitor, recreator, and homeless person. Single-event risk was first evaluated for the three individual exposure scenarios; overall risk was then determined over a 1-year period using Monte Carlo techniques to characterize uncertainty. For fecal Streptococcus and Enterococcus, annualized risk estimates for gastrointestinal illness ranged from approximately 0.42 to 0.53 for recreators, 0.07 to 0.10 for visitors, and 0.62 to 0.72 for homeless individuals across the three sampling locations. Annualized risk of Giardia infection ranged from 0.14 to 0.64 for recreators, 0.01 to 0.1 for visitors, and 0.30 to 0.87 for homeless individuals, across all locations where detected. Cryptosporidium was detected at one location, and the corresponding annualized risk of infection was 0.32, 0.05, and 0.51 for recreators, visitors, and homeless individuals, respectively. This risk assessment suggests that pathogen-contaminated sediments near areas of CSO discharge in the Lower Passaic River could pose a health risk to individuals coming into contact with sediments in the mudflat areas.

Daily assessment of pain in adults with sickle cell disease

BACKGROUND

Researchers of sickle cell disease have traditionally used health care utilization as a proxy for pain and underlying vaso-occlusion. However, utilization may not completely reflect the amount of self-reported pain or acute, painful episodes (crises).

OBJECTIVE

To examine the prevalence of self-reported pain and the relationship among pain, crises, and utilization in adults with sickle cell disease.

DESIGN

Prospective cohort study.

SETTING

Academic and community practices in Virginia.

PATIENTS

232 patients age 16 years or older with sickle cell disease.

MEASUREMENTS

Patients completed a daily diary for up to 6 months, recording their maximum pain (on a scale of 0 to 9); whether they were in a crisis (crisis day); and whether they used hospital, emergency, or unscheduled ambulatory care for pain on the previous day (utilization day). Summary measures included both simple proportions and adjusted probabilities (for repeated measures within patients) of pain days, crisis days, and utilization days, as well as mean pain intensity.

RESULTS

Pain (with or without crisis or utilization of care) was reported on 54.5% of 31 017 analyzed patient-days (adjusted probability, 56%). Crises without utilization were reported on 12.7% of days and utilization on only 3.5% (unadjusted). In total, 29.3% of patients reported pain in greater than 95% of diary days, whereas only 14.2% reported pain in 5% or fewer diary days (adjusted). The frequency of home opiate use varied and independently predicted pain, crises, and utilization. Mean pain intensity on crisis days, noncrisis pain days, and total pain days increased as the percentage of pain days increased (P < 0.001). Intensity was significantly higher on utilization days (P < 0.001). However, utilization was not an independent predictor of crisis, after controlling for pain intensity.

LIMITATIONS

The study was done in a single state. Patients did not always send in their diaries.

CONCLUSION

Pain in adults with sickle cell disease is the rule rather than the exception and is far more prevalent and severe than previous large-scale studies have portrayed. It is mostly managed at home; therefore, its prevalence is probably underestimated by health care providers, resulting in misclassification, distorted communication, and undertreatment.

Extrinsic pathway- and cathepsin-dependent induction of mitochondrial dysfunction are essential for synergistic flavopiridol and vorinostat lethality in breast cancer cells

The present studies have determined whether interactions between the cyclin-dependent kinase inhibitor flavopiridol and the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA; vorinostat; Zolinza) occur in breast cancer cells. MDA-MB-231 and MCF7 cells were treated with flavopiridol (25-100 nmol/L) and vorinostat (125-500 nmol/L) in vitro, and mechanisms of cell killing were determined. Concurrent treatment of cells with flavopiridol and vorinostat or treatment of cells with flavopiridol followed by vorinostat promoted cell killing in a greater than additive fashion. Similar data were obtained with the CDK inhibitor roscovitine. Flavopiridol suppressed c-FLIP-l/s and BCL-xL expression, whereas vorinostat reduced expression of BCL-xL, and combined exposure to flavopiridol and vorinostat reduced MCL-1 and X-chromosome-linked inhibitor of apoptosis protein (XIAP) levels. Pharmacologic or genetic inhibition of caspase-8 reduced flavopiridol toxicity, but abolished killing by vorinostat and cell death caused by the vorinostat/flavopiridol regimen. Loss of BAX/BAK function or loss of BID function modestly reduced flavopiridol toxicity, but abolished vorinostat-mediated potentiation of flavopiridol toxicity, as did inhibition of caspase-9. Inhibition and/or deletion of cathepsin B function significantly attenuated vorinostat/flavopiridol lethality. Flavopiridol suppressed extracellular signal-regulated kinase 1/2 (ERK1/2) and AKT activity and expression of activated forms of AKT and mitogen-activated protein/ERK kinase 1 maintained c-FLIP-l/s, BCL-xL, and XIAP expression and protected cells against flavopiridol/vorinostat lethality. Overexpression of c-FLIP-s and BCL-xL abolished the lethality of flavopiridol/vorinostat. Collectively, these data argue that flavopiridol enhances the lethality of vorinostat in breast cancer cells in part through the inhibition of AKT and ERK1/2 function, leading to reduced expression of multiple inhibitors of the extrinsic and intrinsic apoptosis pathways, as well as activation of cathepsin protease-dependent pathways.

Chemistry of 1-fluoro-2,3,4-triphenylcyclobutadiene dimers

The reaction of 2,4-dichloro-1,1-difluoro-3-phenyl-2-cyclobutene 1 with excess phenyllithium and subsequent transformations of the products have been reinvestigated. The phenyllithium reaction appears to proceed through the intermediacy of a fluorotriphenylcyclobutadiene 2 to produce a well-characterized dimeric trans-hexaphenyldifluorotricyclooctadiene 3a. Subsequent transformations of 3a gave a pentaphenyldihydrodifluoropentalene 4, which on acid hydrolysis formed a pentaphenyldihydropentalenone 5. When 3a was photolyzed in benzene, after purification, it afforded 6, an isomer of 5, probably by way of 7, an isomer of 4. Thermolysis of 3a also provided, in low yield, a substance believed to be a pentaphenylfluorophenanthrene 8. Along with isolation of 3a, and probably arising from a different isomer of the 3 family, was a pentaphenylfluorophenanthrene 9, which was suspected of being an isomer of 8. Single-crystal X-ray studies were used to derive structures for 4, 5, 6, and 9. Formation of the unusual and intriguing transformation products has at least been rationalized.

Conformational Equilibria of Ethanolamine and Its Hydrochloride in Solution

The conformational preferences of ethanolamine and its hydrochloride in solution were estimated by comparing experimental NMR vicinal proton-proton coupling constants to semiemprical coupling constants for each staggered rotamer, derived by the Haasnoot-Altona method. Strong gauche preferences are observed for both ethanolamine and its hydrochloride over a wide range of solvent polarities. Concentration was not observed to significantly affect the position of the conformer equilibria.

Conformational analysis of 3-(trimethylsilyl)propionic acid by NMR spectroscopy: an unusual expression of the beta-silyl effect

The rotational freedom of the carbon-carbon single bonds of 1,2-disubstituted ethanes affords the possibility of these compounds existing as a rapidly interconverting mixture of conformers in solution. The conformational preferences of one such compound, 3-(trimethylsilyl)propionic acid, and its anion were studied in water, dimethyl sulfoxide, methanol, ethanol, isopropyl alcohol, tert-butyl alcohol, tetrahydrofuran, and toluene with 1H NMR spectroscopy. The conformational preferences were determined from the vicinal proton-proton coupling constants between the hydrogen nuclei of the CH(2)CH(2) group with the aid of the Altona equations to derive the equilibrium anti and gauche percentages of rotamers from the averaged NMR-time scale couplings. Conformational analyses of 4,4-dimethylpentanoic acid and its anion as well as 2-(trimethylsilyl)ethanesulfonate anion were also conducted to compare the relative structural influences on the conformational preferences of silicon and carbon.

Patient satisfaction in specialized versus nonspecialized adult sickle cell care centers: the PiSCES study

BACKGROUND

Sickle cell disease (SCD) patients can receive their ambulatory care from either SCD specialists (caregivers with sickle cell-only clinics) or nonspecialized care centers. Patient satisfaction, an important factor that may influence compliance and outcome, can differ between the two groups because of the perceived quality of care, outcomes or practice style.

METHODS

We administered a patient satisfaction survey to 308 participants in an SCD prospective cohort study. Of the 308 patients, 133 (43.2%) received the majority of their SCD care at specialized centers, 152 (49.3%) received their care from nonspecialized centers and 26 (7.5) did not provide information. The satisfaction surveys measured general satisfaction (GS), technical quality (TQ), interpersonal manner (IM), communication (CM), financial aspects (FA), time spent with doctor (TA), and accessibility and convenience (AC). Patients reported their levels of satisfaction using a five-point Likert scale. We compared unadjusted group means, as well as means adjusted for potential confounders such as marital status, on patient satisfaction between specialized and nonspecialized centers.

RESULTS

SCD patients who received their care from specialized centers had significantly higher mean satisfaction scores, compared to those who received their care from nonspecialized centers: GS 4.00(+/-0.93) vs. 3.66 (+/- 01.16, p=0.0326), TQ 3.98 (+/- 0.77) vs. 3.65 (+/- 0.91, p=0.0058), AC 3.83 (+/-0.79) vs. 3.51 (+/- 1.02, p=0.0142) , FA 3.88 (+/-0.96) vs. 3.49 (+/-1.25, p=0.0120). There were no statistically significant group differences in IM, TA and CM.

CONCLUSION

SCD patients who received most of their SCD care from specialized centers had somewhat higher satisfaction scores in some areas when compared with patients who received their care from nonspecialized centers.

Low-Dose BBR3610 Toxicity in Colon Cancer Cells Is p53-Independent and Enhanced by Inhibition of Epidermal Growth Factor Receptor (ERBB1)-Phosphatidyl Inositol 3 Kinase Signaling

We have examined the mechanisms by which the multinuclear platinum chemotherapeutic BBR3610 kills human colon cancer cells. BBR3610 more efficiently killed HCT116, DLD1, SW480, and HT29 cells than BBR3464, cisplatin, or oxaliplatin. The amount of platinum uptake per cell and its incorporation into DNA were identical for BBR3464 and BBR3610. BBR3610 lethality (IC(75)) was unaltered comparing HCT116 wild-type and p53-/- cells, was reduced in p21-/- cells, and was enhanced in K-RAS D13 null cells. Small molecule or molecular inhibition of epidermal growth factor receptor (ERBB1) or phosphatidyl inositol 3 kinase (PI3K) enhanced BBR3610 toxicity in HCT116, DLD1, and SW480 cells. Small molecule or molecular inhibition of caspase 8 function abolished the toxicity of BBR3610 and of BBR3610 + ERBB1 inhibitor treatments, whereas inhibition of caspase 9 suppressed the ability of ERBB1 inhibitors to enhance BBR3610 lethality. Treatment with BBR3610 reduced AKT activity; the expression of dominant-negative AKT enhanced and expression of constitutively active AKT suppressed, respectively, the toxicity of BBR3610 and of BBR3610 + ERBB1 inhibitor treatments. Treatment with BBR3610 reduced expression of c-FLIP-s and MCL-1, levels that were maintained in cells expressing constitutively active AKT. Overexpression of c-FLIP-s or loss of BID function suppressed BBR3610 toxicity, whereas overexpression of XIAP or Bcl-xL suppressed the potentiation of cell killing by ERBB1 inhibitors. Collectively, our data argue that BBR3610 promotes cell killing via a caspase 8-dependent mechanism, which can be enhanced by ERBB1/PI3K inhibitors that promote additional BBR3610-dependent cell killing via activation of BAX and caspase 9.

Probing Molecular Shape. 1. Conformational Studies of 5-Hydroxyhexahydropyrimidine and Related Compounds

Understanding the factors that determine molecular shape enables scientists to begin to understand and tailor molecular properties and reactivity. Many biomolecules and bioactive compounds contain aliphatic heterocyclic rings whose conformations play a major role in their biological activity. The interplay of a number of factors, both steric and electronic, is examined for 5-hydroxyhexahydropyrimidine (1) and related compounds with use of spectroscopy and molecular modeling.

Fascination with the conformational analysis of succinic acid, as evaluated by NMR spectroscopy, and why

A serendipitous effort to use NMR spectroscopy to determine the conformational preferences of succinate monoanion opened a Pandora's box of unexpected uncertainties as to what influences such preferences of succinic acid in its various ionization states, not only in water but also in other less polar protic solvents, as well as a range of aprotic solvents. The dianion in aprotic solvents shows substantial gauche preferences, which give the appearance of violating Coulomb's law.

Human chorionic gonadotropin modulates prostate cancer cell survival after irradiation or HMG CoA reductase inhibitor treatment

The impact of human chorionic gonadotropin (hCG) on prostate carcinoma viability was investigated. Treatment of LNCaP and PC-3 cells with hCG modestly reduced cell viability within 96 h. Treatment of cells with hCG followed by exposure to ionizing radiation enhanced radiosensitivity. Exposure of LNCaP cells to hCG promoted activation of epidermal growth factor receptor (ERBB1) via a Galpha(i)-, mitogen-activated protein kinase kinase (MEK)1/2-, and metalloprotease-dependent paracrine mechanism, effects that were further enhanced after radiation exposure, and that were causal in prolonged intense activation of poly(ADP-ribose) polymerase (PARP). Inhibition of ERBB1, MEK1, or PARP1 function suppressed the radiosensitizing properties of hCG. Radiosensitization was also, in part, dependent upon c-Jun NH2-terminal kinase 1/2 signaling. PARP1-dependent radiosensitization was suppressed by a pan-caspase inhibitor and by knockdown of apoptosis-inducing factor expression. Inhibition of phosphatidylinositol 3-kinase, expression of dominant-negative AKT, or treatment with the HMG CoA reductase inhibitor lovastatin suppressed AKT phosphorylation and enhanced the cytotoxic effects of hCG. The enhancing effect of lovastatin was reproduced by incubation with a geranylgeranyl transferase inhibitor and blocked by coexposure to geranylgeranyl pyrophosphate. Treatment with hCG and lovastatin decreased expression of BCL-(XL) and XIAP, and increased expression of IkappaB. The cytotoxic effects of hCG were enhanced by expression of dominant-negative IkappaB, and they were abolished by coexpression of activated AKT. Expression of activated AKT maintained BCL-(XL) levels in cells expressing dominant-negative IkappaB. The promotion of hCG lethality by lovastatin was abolished by overexpression of BCL-(XL), and was dependent upon activation of caspase-9. Thus, hCG, in combination with radiation and lovastatin, may represent a novel approach to kill prostate cancer cells.

Intramolecular hydrogen bonding in disubstituted ethanes: general considerations and methodology in quantum mechanical calculations of the conformational equilibria of succinamate monoanion

The importance of intramolecular hydrogen bonding between the carboxylate oxygen and amide proton of succinamate anion has been investigated by quantum mechanical simulations as a function of solvent for comparison with conformational equilibria estimated by NMR spectroscopy. The focus is on those methodological considerations of general interest to the conformational equilibrium problem, which are also particularly relevant to the quantum calculations. The roughly planar symmetry of the amide and carboxylate substituents of succinamate anion and the possibility of intramolecular hydrogen-bond formation together suggest that the orientational degrees of freedom of the substituents could play an important role in the equilibrium of the CH2-CH2 torsion. To test this hypothesis, two-dimensional potential-energy surfaces (PESs) were mapped out from the quantum mechanical calculations, with coordinates corresponding to the CH2-CH2 torsional and amide group rotational degrees of freedom. The Boltzmann populations obtained from two-dimensional PESs and those obtained from a one-dimensional adiabatic surface for the CH2-CH2 torsion were compared with the experimental results. In these comparisons, the agreement of calculated gauche fractions with corresponding experimental values was checked, as well as the agreement between predicted coupling constants and those determined from experimental spectra. In polar protic and aprotic solvents, where highly polar trans conformations can be stabilized by dipole-dipole and hydrogen-bonding interactions with the solvent, the orientational degree of freedom of the amide substituent appears to play a sufficiently important role in the CH2-CH2 torsional equilibrium that it cannot be safely ignored in the simulations.

Phase I Study of Bryostatin 1 and Fludarabine in Patients with Chronic Lymphocytic Leukemia and Indolent (Non-Hodgkin's) Lymphoma

PURPOSE

Preclinical studies suggested that bryostatin 1 might potentiate the therapeutic effects of fludarabine in the treatment of hematologic malignancies. We undertook a phase I study to identify appropriate schedules and doses of bryostatin 1 and fludarabine to be used in phase II studies.

EXPERIMENTAL DESIGN

Patients with chronic lymphocytic leukemia (CLL) or indolent lymphoma received fludarabine daily for 5 days and a single dose of bryostatin 1 via a 24-hour continuous infusion either before or after the fludarabine course. Doses were escalated in successive patients until recommended phase II doses for each sequence were identified on the basis of dose-limiting toxic events.

RESULTS

Bryostatin 1 can be administered safely and tolerably with full dose fludarabine (25 mg/m(2)/d x 5). The recommended bryostatin 1 phase II dose is 50 microg/m(2) for both sequences, bryostatin 1 --> fludarabine and fludarabine --> bryostatin 1. The combination is active against both CLL and indolent lymphomas with responses seen in patients who had been previously treated with fludarabine. Correlative studies do not support the hypothesis that bryostatin 1 potentiates fludarabine activity through down-regulation of protein kinase C in target cells.

CONCLUSIONS

Bryostatin 1 can be administered with full dose fludarabine, and the combination is moderately active in patients with persistent disease following prior treatment. In view of the activity of monoclonal antibodies such as the anti-CD20 monoclonal antibody rituximab in the treatment of CLL and indolent lymphomas, the concept of combining bryostatin 1 and fludarabine with rituximab warrants future consideration.

P-selectin activates integrin-mediated colon carcinoma cell adhesion to fibronectin

During hematogenous cancer metastasis, tumor cells separate from a primary mass, enter the bloodstream, disperse throughout the body, migrate across vessel walls, and generate distant colonies. The later steps of metastasis superficially resemble leukocyte extravasation, a process initiated by selectin-mediated cell tethering to the blood vessel wall followed by integrin-mediated arrest and transendothelial migration. Some cancer cells express P-selectin ligands and attach to immobilized P-selectin, suggesting that these cells can arrest in blood vessels using sequential selectin- and integrin-mediated adhesion, as do leukocytes. We hypothesize that selectin binding may regulate subsequent integrin-mediated steps in metastasis. Using a model system of cultured Colo 320 human colon adenocarcinoma cells incubated with soluble P-selectin-IgG chimeric protein, we have found that P-selectin can stimulate activation of the alpha(5)beta(1) integrin resulting in a specific increase of adhesion and spreading of these cells on fibronectin substrates. P-selectin binding also induced activation of p38 mitogen-activated protein kinase (p38 MAPK) and phosphatidylinositol 3-kinase (PI3-K). PI3-K inhibitors blocked P-selectin-mediated integrin activation, cell attachment, and cell spreading. Inhibition of p38 MAPK activation blocked cell spreading, but not cell attachment. P-selectin binding also resulted in formation of a signaling complex containing PI3-K and p38 MAPK. These results suggest that P-selectin binding to tumor cells can activate alpha(5)beta(1) integrin via PI3-K and p38 MAPK signaling pathways leading to increased cell adhesion. We propose that P-selectin ligands are important tumor cell signaling molecules that modulate integrin-mediated cell adhesion in the metastatic process.

Fitness consequences of variable maternal provisioning in quacking frogs (Crinia georgiana)

Variable maternal provisioning may evolve when there is variation in the quality of offspring environments. The frog Crinia georgiana has high variability in egg size both within and between clutches, independent of female phenotype. It breeds in ponds with high spatial and temporal variation in habitat quality. Egg size strongly affected offspring fitness in good and poor quality offspring environments, whether the egg size difference was from between or within clutches. Since there is a trade-off in egg size and number, these fitness consequences translate to strong effects on maternal fitness. In the variable and unpredictable offspring environment of C. georgiana, the maintenance of variable maternal provisioning both within and between clutches is likely to be an evolved response to the offspring environment.

E2F1 amplication and genetic heterogeneity in melanoma

Amplification and increased expression of the transcription factor E2F1 occurs (and may be common in) melanoma and presumably promotes melanoma cell proliferation. Previous work indicates that most melanomas contain genetic alterations in either the MAPK or Rb pathways and that a clinical classification based upon melanoma primary location and the presence or absence of chronic sun-induced damage predicts for distinct patterns of genetic alteration. E2F1 may cooperate with alterations in the MAPK or Rb pathways in the promotion of proliferation in many or most types of melanoma and may become a target for therapeutic intervention.