Dexamethasone synergizes with lenalidomide to inhibit multiple myeloma tumor growth, but reduces lenalidomide-induced immunomodulation of T and NK cell function

To determine the effect of dexamethasone on the antimyeloma effects of lenalidomide, we tested in vitro proliferation, tumor suppressor gene expression, caspase activity, cell cycling, and apoptosis levels in a series of multiple myeloma (MM) and plasma cell leukemia cell lines treated with lenalidomide and dexamethasone, alone or in combination. The effect of dexamethasone on the immunomodulatory activities of lenalidomide such as T cell and natural killer (NK) cell activation was measured via interleukin [IL]-2 production, and interferon-gamma and granzyme B production respectively. Lenalidomide inhibited proliferation in most cell lines tested, and this effect was enhanced by dexamethasone. This effect was observed in MM cells containing the high-risk cytogenetic abnormalities t(4;14), t(14;16), del17p, del13, and hypodiploidy. Mechanistically, lenalidomide plus dexamethasone synergistically induced expression of the tumor suppressor genes Egr1, Egr2, Egr3, p15, p21, and p27 in MM cell lines and MM patient cells. The combination activated caspases 3, 8, and 9; and induced cell cycle arrest and apoptosis. Lenalidomide alone increased T cell production of IL-2, and NK cell production of interferon-gamma and granzyme B. Notably, dexamethasone antagonized these immunostimulatory effects of lenalidomide in a dose-dependent manner. These data further elucidate the mechanism of action of lenalidomide and dexamethasone in MM, and suggest that use of low-dose dexamethasone with lenalidomide may retain the antiproliferative effect of lenalidomide while permitting greater immunomodulatory effects of this combination regimen.

Twelve-month outcomes and predictors of very stable INR control in prevalent warfarin users

BACKGROUND

For patients on warfarin therapy an international normalized ratio (INR) recall interval not exceeding 4 weeks has traditionally been recommended. For patients whose INR values are nearly always therapeutic, less frequent INR monitoring may be feasible.

OBJECTIVE

To identify patients with stable INRs (INR values exclusively within the INR range) and comparator patients (at least one INR outside the INR range), compare occurrences of thromboembolism, bleeding and death between groups, and identify independent predictors of stable INR control.

METHODS

The study was a retrospective, longitudinal cohort study using data extracted from electronic databases. Patient characteristics and risk factors were entered into multivariate logistic regression models to identify variables that independently predict stable INR status.

RESULTS

There were 533 stable and 2555 comparator patients. Bleeding and thromboembolic complications were significantly lower in stable vs. comparator patients (2.1% vs. 4.1% and 0.2% vs. 1.3%, respectively; P < 0.05). Independent predictors of stable INR control were age >70 years, male gender and the absence of heart failure. Stable patients were significantly less likely to have target INR > or =3.0 or chronic diseases.

CONCLUSION

A group of patients with exclusively therapeutic INR values over 12 months is identifiable. In general, these patients are older, have a target INR <3.0, and do not have heart failure and/or other chronic diseases. Our findings suggest that many patients whose INR values remain within the therapeutic range over time could be safely treated with INR recall intervals >4 weeks.

Hyperpolarized MR imaging: neurologic applications of hyperpolarized metabolism

Hyperpolarization is the general term for a method of enhancing the spin-polarization difference of populations of nuclei in a magnetic field. No less than 5 distinct techniques (dynamic nuclear polarization [DNP]; parahydrogen-induced polarization-parahydrogen and synthesis allow dramatically enhanced nuclear alignment [PHIP-PASADENA]; xenon/helium polarization transfer; Brute Force; (1)H hyperpolarized water) are currently under exhaustive investigation as means of amplifying the intrinsically (a few parts per million) weak signal intensity used in conventional MR neuroimaging and spectroscopy. HD-MR imaging in vivo is a metabolic imaging tool causing much of the interest in HD-MR imaging. The most successful to date has been DNP, in which carbon-13 ((13)C) pyruvic acid has shown many. PHIP-PASADENA with (13)C succinate has shown HD-MR metabolism in vivo in tumor-bearing mice of several types, entering the Krebs-tricarboxylic acid cycle for ultrafast detection with (13)C MR imaging, MR spectroscopy, and chemical shift imaging. We will discuss 5 promising preclinical studies: (13)C succinate PHIP in brain tumor; (13)C ethylpyruvate DNP and (13)C acetate; DNP in rodent brain; (13)C succinate PHIP versus gadolinium imaging of stroke; and (1)H hyperpolarized imaging. Recent developments in clinical (13)C neurospectroscopy encourage us to overcome the remaining barriers to clinical HD-MR imaging.

The aerobiology of the environment around mechanically ventilated broiler sheds

AIM

To investigate the aerobiology of the environment around mechanically ventilated broiler sheds with the aim of understanding dispersion in the surrounding environment.

METHODS AND RESULTS

Aerosol samples were collected weekly on four different commercial broiler farms through the cycle of 55 days from 2005 to 2007. Samples were collected inside the shed and at varying distances from the sheds. Litter and dust from within the shed were also examined. Members of the genera Staphylococcus (and to a lesser extent Corynebacterium) dominated (10(6) CFU m(-3)) in the outside air at 20 m from the fan and were shown to decrease with distance. At distances of around 400 m, the levels of staphylococci/coryneforms returned to levels typical of those present before the placement of chickens. Escherichia coli levels were low (maximum 100 CFU m(-3)) at 20 m. Fungi were present at uniform levels across the broiler cycle.

CONCLUSIONS

Staphylococci are the dominant organisms present in the air around mechanically ventilated broiler sheds and have the potential to act as an airborne 'marker organism'. SIGNIFICANT IMPACT OF THE STUDY: The outcomes of this study suggest that the impact of aerosols emitted from broiler sheds could be monitored and managed by examining the levels of staphylococci/coryneforms.

Reduced mucin sulfonation and impaired intestinal barrier function in the hyposulfataemic NaS1 null mouse

OBJECTIVE

Sulfate (SO(4)(2-)) is an abundant component of intestinal mucins and its content is decreased in certain gastrointestinal diseases, including inflammatory bowel disease. In this study, the hyposulfataemic NaS1 sulfate transporter null (Nas1(-/-)) mice were used to investigate the physiological consequences of disturbed sulfate homeostasis on (1) intestinal sulfomucin content and mRNA expression; (2) intestinal permeability and proliferation; (3) dextran sulfate sodium (DSS)-induced colitis; and (4) intestinal barrier function against the bacterial pathogen, Campylobacter jejuni.

METHODS

Intestinal sulfomucins and sialomucins were detected by high iron diamine staining, permeability was assessed by fluorescein isothiocyanate (FITC)-dextran uptake, and proliferation was assessed by 5-bromodeoxyuridine (BrdU) incorporation. Nas1(-/-) and wild-type (Nas1(+/+)) mice received DSS in drinking water, and intestinal damage was assessed by histological, clinical and haematological measurements. Mice were orally inoculated with C jejuni, and intestinal and systemic infection was assessed. Ileal mRNA expression profiles of Nas1(-/-) and Nas1(+/+) mice were determined by cDNA microarrays and validated by quantitative real-time PCR.

RESULTS

Nas1(-/-) mice exhibited reduced intestinal sulfomucin content, enhanced intestinal permeability and DSS-induced colitis, and developed systemic infections when challenged orally with C jejuni. The transcriptional profile of 41 genes was altered in Nas1(-/-) mice, with the most upregulated gene being pancreatic lipase-related protein 2 and the most downregulated gene being carbonic anhydrase 1 (Car1).

CONCLUSION

Sulfate homeostasis is essential for maintaining a normal intestinal metabolic state, and hyposulfataemia leads to reduced intestinal sulfomucin content, enhanced susceptibility to toxin-induced colitis and impaired intestinal barrier to bacterial infection.

The epidemiology of herpes zoster in patients with invasive cancer

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Background: Given the limited available data, the aim of this study was to estimate the incidence of Herpes Zoster (HZ) in cancer patients. Methods: In this retrospective cohort study, we used the Kaiser Permanente Northern California cancer registry to identify adult health plan members diagnosed with an invasive hematologic malignancy (HM) or solid tumor malignancy (STM) during 2001–2005. Potential episodes of HZ were ascertained from time of cancer diagnosis through 2006 from electronic databases using inpatient and outpatient diagnoses, laboratory tests, and prescriptions for antivirals. HZ diagnoses were confirmed by abstraction and clinical review of information from patients' inpatient and outpatient medical records. Incidence rates were calculated as the number of new occurrences of HZ per person-time of follow-up. Age-standardized incidence ratios (SIRs) were computed to compare HZ rates in cancer patients to reported rates in the general population (Yawn et al, 2007). Results: Among the 4,728 STM patients (mean age 66 years, range 18–102), the rate of HZ was 12/1000 person years (py) of follow-up (total 9170 py). Among the 1504 HM patients (mean age 67 years, range 18–97), the rate of HZ was 33/1000 py (total 2355 py). The SIRs and 95% confidence intervals for STM and HM were 1.7 (1.4–2.1) and 4.5 (3.5–5.6), respectively. Among patients with HM, incidence rates were highest in the first year after cancer diagnosis (40/1000 py); rates did not appear to vary markedly over time among patients with STM. For either cancer type, HZ rates were similar for males and females and did not increase consistently with increasing age. Conclusions: Compared to the general population, the incidence of HZ was nearly 2 times higher in patients with STM and over 4 times higher in patients with HM. HZ rates did not differ markedly by age or gender.

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A phase I study of pemetrexed plus carboplatin or cisplatin with concurrent chest radiation therapy (CRT) for patients with locally advanced non-small cell lung cancer (LANSCLC)

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Background: Pemetrexed is a multi-targeted antifolate that inhibits the synthesis of both pyrimidines and purines. Pemetrexed is an effective new chemotherapeutic agent in advanced non-small cell lung cancer. Pemetrexed has also shown preclinical activity as a radiosensitizer in lung cancer. A phase I study was performed to establish the maximum tolerated dose (MTD) and phase 2 dose of carboplatin or cisplatin given with pemetrexed and CRT in LANSCLC. Methods: Patients (pts) with LANSCLC were enrolled. Initial intent was to establish the MTD of both weekly cisplatin and weekly carboplatin in combination with pemetrexed and CRT as an alternating two-arm phase I trial. Subsequently and based on early results from the CALGB 30407 trial (also evaluating the MTD of carboplatin), the protocol was amended to establish the safety of the planned phase II doses of cisplatin and carboplatin combined with pemetrexed 500 mg/m2 and given every 3 weeks with concurrent CRT. Dose limiting toxicity (DLT) was defined as ≥ Grade 3 hematologic or nonhematologic toxicity based on Common Terminology Criteria for Adverse Events (CTCAE) version 3.0. MTD was determined by occurrence of 2 DLTs among 6 pts in each cohort. Results: 22 pts were enrolled on 3 cohorts. All pts received pemetrexed, 9 with carboplatin AUC=2, 9 with cisplatin 30 mg/m2, and 4 with cisplatin 75 mg/m2. One DLT occurred in each of the carboplatin and cisplatin 30 mg/m2 cohorts, prompting enrollment of 3 additional patients. No DLTs were seen in the cisplatin 75 mg/m2 cohort. Conclusions: The MTD of cisplatin in combination with pemetrexed and CRT was not reached. Based on these results and those from CALGB 30407, either carboplatin AUC=5 or cisplatin 75 mg/m2 in combination with pemetrexed 500 mg/m2 given every 3 weeks with CRT appears to be well tolerated, and are currently being studied in a randomized phase II trial in pts with LANSCLC.

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rf streak camera based ultrafast relativistic electron diffraction

We theoretically and experimentally investigate the possibility of using a rf streak camera to time resolve in a single shot structural changes at the sub-100 fs time scale via relativistic electron diffraction. We experimentally tested this novel concept at the UCLA Pegasus rf photoinjector. Time-resolved diffraction patterns from thin Al foil are recorded. Averaging over 50 shots is required in order to get statistics sufficient to uncover a variation in time of the diffraction patterns. In the absence of an external pump laser, this is explained as due to the energy chirp on the beam out of the electron gun. With further improvements to the electron source, rf streak camera based ultrafast electron diffraction has the potential to yield truly single shot measurements of ultrafast processes.

Experimental generation and characterization of uniformly filled ellipsoidal electron-beam distributions

For 40 years, uniformly filled ellipsoidal beam distributions have been studied theoretically, as they hold the promise of generating self-fields linear in the coordinate offset in all three directions. Recently, a scheme for producing such distributions, based on the strong longitudinal expansion of an initially very short beam under its own space-charge forces, has been proposed. In this Letter we present the experimental demonstration of this scheme, obtained by illuminating the cathode in a rf photogun with an ultrashort laser pulse (approximately 35 fs rms) with an appropriate transverse profile. The resulting 4 MeV beam spatiotemporal (x,t) distribution is imaged using a rf deflecting cavity with 50 fs resolution. A temporal asymmetry in the ellipsoidal profile, due to image charge effects at the photocathode, is observed at higher charge operation. This distortion is also found to degrade the transverse beam quality.