Peripheral blood lymphocytes differ in DNA damage response after exposure to X-rays with different physical properties

Introduction: In radiology, low X-ray energies (<140 keV) are used to obtain an optimal image while in radiotherapy, higher X-ray energies (MeV) are used to eradicate tumor tissue. In radiation research, both these X-ray energies being used to extrapolate in vitro research to clinical practice. However, the energy deposition of X-rays depends on their energy spectrum, which might lead to changes in biological response. Therefore, this study compared the DNA damage response (DDR) in peripheral blood lymphocytes (PBLs) exposed to X-rays with varying beam quality, mean photon energy (MPE) and dose rate.Methods: The DDR was evaluated in peripheral blood lymphocytes (PBLs) by the ɣ-H2AX foci assay, the cytokinesis-block micronucleus assay and an SYTOX-based cell death assay, combined with specific cell death inhibitors. Cell cultures were irradiated with a 220 kV X-ray research cabinet (SARRP, X-Strahl) or a 6 MV X-ray linear accelerator (Elekta Synergy). Three main physical parameters were investigated: beam quality (V), MPE (eV) and dose rate (Gy/min). Additional copper (Cu) filtration caused variation in the MPE (78 keV, 94 keV, 118 keV) at SARRP; dose rates were varied by adjusting tube current for 220 kV X-rays (0.33-3 Gy/min) or water-phantom depth in the 6 MV set-up (3-6 Gy/min).Results: The induction of chromosomal damage and initial (30 min) DNA double-stranded breaks (DSBs) were significantly higher for 220 kV X-rays compared to 6 MV X-rays, while cell death induction was similar. Specific cell death inhibitors for apoptosis, necroptosis and ferroptosis were not capable of blocking cell death after irradiation using low or high-energy X-rays. Additional Cu filtration increased the MPE, which significantly decreased the amount of chromosomal damage and DSBs. Within the tested ranges no specific effects of dose rate variation were observed.Conclusion: The DDR in PBLs is influenced by the beam quality and MPE. This study reinforces the need for consideration and inclusion of all physical parameters in radiation-related studies.

Assisting walking balance using a bio-inspired exoskeleton controller

BACKGROUND

Balance control is important for mobility, yet exoskeleton research has mainly focused on improving metabolic energy efficiency. Here we present a biomimetic exoskeleton controller that supports walking balance and reduces muscle activity.

METHODS

Humans restore balance after a perturbation by adjusting activity of the muscles actuating the ankle in proportion to deviations from steady-state center of mass kinematics. We designed a controller that mimics the neural control of steady-state walking and the balance recovery responses to perturbations. This controller uses both feedback from ankle kinematics in accordance with an existing model and feedback from the center of mass velocity. Control parameters were estimated by fitting the experimental relation between kinematics and ankle moments observed in humans that were walking while being perturbed by push and pull perturbations. This identified model was implemented on a bilateral ankle exoskeleton.

RESULTS

Across twelve subjects, exoskeleton support reduced calf muscle activity in steady-state walking by 19% with respect to a minimal impedance controller (p < 0.001). Proportional feedback of the center of mass velocity improved balance support after perturbation. Muscle activity is reduced in response to push and pull perturbations by 10% (p = 0.006) and 16% (p < 0.001) and center of mass deviations by 9% (p = 0.026) and 18% (p = 0.002) with respect to the same controller without center of mass feedback.

CONCLUSION

Our control approach implemented on bilateral ankle exoskeletons can thus effectively support steady-state walking and balance control and therefore has the potential to improve mobility in balance-impaired individuals.

A systematic review of the predictive value of 18F-fluoro-2-deoxyglucose positron emission tomography on survival in locally advanced rectal cancer after neoadjuvant chemoradiation

AIM

Treatment of locally advanced rectal cancer (LARC) includes preoperative radiation therapy with or without chemotherapy followed by radical surgery, but the clinical outcome is uncertain. A systemic review was carried out to determine the predictive value of (18)F-fluoro-2-deoxyglucose positron emission tomography ((18)FDG-PET) for assessing disease-free (DFS) and overall survival (OS) in LARC.

METHOD

A literature search (PubMed/MEDLINE, EMBASE, Cochrane) up to January 2012 to identify full papers with sequential (18)FDG-PET and survival data, using indexing terms and free text words. The inclusion criteria were: a study of at least 10 patients, having sequential (18)FDG-PET imaging before and after adjuvant chemoradiation and a minimal follow-up of 24 months. Studies were selected by two of the authors. A meta-analysis was performed for DFS and OS using the hazard ratio (HR) as the primary outcome.

RESULTS

Five eligible studies were identified including 330 patients (mean age 63 years, 64% men), in which PET-CT or PET imaging was used. The American Joint Committee on Cancer stage distribution was as follows: Stage I, 2%; Stage II, 44%; Stage III, 52%; Stage IV, 1%. The pooled HRs for complete metabolic response versus partial or no response were 0.39 (95% CI 0.18-0.86; P = 0.02) for OS and 0.70 (95% CI 0.16-3.14; P = 0.64) for DFS. The lack of significance for DFS might be explained by different follow-up characteristics. There was also clinical heterogeneity among the different studies.

CONCLUSION

This systematic review indicates that complete metabolic response on sequential (18)FDG-PET data after preoperative chemoradiation of LARC is predictive of OS, but not of DFS.

Stratified phase II trial of cetuximab in patients with recurrent high-grade glioma

BACKGROUND

To evaluate the antitumor activity and toxicity of single-agent cetuximab in patients with recurrent high-grade glioma (HGG) after failure of surgery, radiation therapy, and chemotherapy.

PATIENTS AND METHODS

In this two-arm, open-label, phase II study patients were stratified according to their epidermal growth factor receptor (EGFR) gene amplification status. Cetuximab was administered intravenously at a dose of 400 mg/m(2) on week 1 followed by weekly dose of 250 mg/m(2). The primary end point for this study was the response rate in both study arms separately.

RESULTS

Fifty-five eligible patients (28 with and 27 without EGFR amplification) tolerated cetuximab well. Three patients (5.5%) had a partial response and 16 patients (29.6%) had stable disease. The median time to progression was 1.9 months [95% confidence interval (CI) 1.6-2.2 months]. Whereas the progression-free survival (PFS) was <6 months in the majority (n = 50/55) of patients, five patients (9.2%) had a PFS on cetuximab of >9 months. Median overall survival was 5.0 months (95% CI 4.2-5.9 months). No significant correlation was found between response, survival and EGFR amplification.

CONCLUSIONS

Cetuximab was well tolerated but had limited activity in this patient population with progressive HGG. A minority of patients may derive a more durable benefit but were not prospectively identified by EGFR gene copy number.

A phase I study of sorafenib in association with docetaxel-prednisone in chemonaive metastatic castration-resistant prostate cancer

5153

Background: Docetaxel (D)-prednisone (P) is the standard regimen for metastatic castrate-resistant prostate cancer (mCRPC). Sorafenib (S) is a dual-action kinase inhibitor that blocks cell proliferation and angiogenesis with antitumor activity in CRPC. The objectives were dose limiting toxicities (DLTs)/recommended dose (RD) of S in combination with D-P, pharmacokinetics (PK), and safety at the RD in an expanded cohort. Methods: 6 pts were enrolled per dose level (DL). All pts received D 75 mg/m2/3 wks in 6 chemotherapy cycles and P 10 mg/d. S dose escalation included 4 DL. DL 1: S 200 mg bid from day 3 to 19 of each chemotherapy cycle. DL 2: S 200 mg bid started at day 3 of the 1st cycle and continued without interruption through the cycles. DL 3: S 400 mg bid from day 3 to 19 of each cycle. DL 4: S 400 mg bid started at day 3 of the 1st cycle without interruption through the cycles. DLTs were determined during the first cycle. Results: 24 chemo-naive mCRPC pts (median age 68) were included in the dose-escalation study. PK analysis showed that mean Cmax and AUC of D were increased at cycle 2 in cohort 2, 3, and 4 indicating a PK interaction dependent on the exposure to S. For the 24 pts, the main Gr 3–4 toxicities (N pts) were febrile neutropenia (8), uncomplicated neutropenia (5), and hand-foot syndrome (4). No DLT was found. PSA response (> 50% in PSA decrease) was recorded in 15 out of 20 pts. Conclusions: The RD of S in combination with D is 400 mg bid continuously. PK analysis revealed an interaction between D and S that may explain the high rate of febrile neutropenia and Gr4 neutropenia. 14 pts were included in an expanded cohort to further explore the safety of this regimen. Updated data will be presented.

[Table: see text]

No significant financial relationships to disclose.

Agrobacterium radiobacter bacteremia in oncologic and geriatric patients: presentation of two cases and review of the literature

INTRODUCTION

We report here two cases of Agrobacterium radiobacter bacteremia. These cases were observed at the same institution over a short time period (3 months).

CASE REPORTS

The first patient was a female cancer patient receiving third-line chemotherapy for ovarian carcinoma. When she developed bacteremia, she was neutropenic and had an indwelling catheter that was removed as part of the treatment. The second case was a geriatric patient admitted from home with bacteremia, clinical signs of septic shock, and concomitant acute cholecystitis.

OUTCOME

Both patients responded promptly and completely to antibiotherapy. No recurrence was observed.

Ovarian cancer associated with carcinomatous meningitis: a case report and review of the literature

We report the case of a 62-year-old patient who developed a carcinomatous meningitis while on second-line chemotherapy for ovarian cancer. Cytologic analyses confirmed that carcinomatous cells of ovarian origin were present in cerebrospinal fluid. Carcinomatous meningitis is a very rare event in the natural history of ovarian carcinoma. We discuss the specificity of our case in the light of the literature. In addition, we present some relevant radiologic and pathologic documents illustrating this rare entity.

Saccharomyces cerevisiae fungemia in a head and neck cancer patient: a case report and review of the literature

We report the case of a 65-year old male who developed Saccharomyces cerevisiae fungemia after completing a course of concomitant chemotherapy and radiation therapy for head and neck carcinoma. He had grade IV oral mucositis, and received Saccharomyces boulardii (Perenterol) orally as treatment for aseptic diarrhoea just before the onset of fungemia. We discuss the epidemiology and pathology of Saccharomyces cerevisiae in the cancer patient population.

Influence of timing of administration of 5-fluorouracil to donors on bone marrow engraftment in nonmyeloablated hosts

We evaluated the engraftment and the cell cycle status of marrow cells at various times after 5-fluorouracil (5-FU) administration. 5-FU (150 mg/kg) was given to donor male BALB/c mice at 1, 2, 6, or 12 days prior to marrow harvest. The donor cells were then assessed in host nonmyeloablated female mice. Bone marrow engraftment of marrow treated with 5-FU was evaluated and compared to marrow treated with diluent (phosphate-buffered saline) at 3 and 10 weeks after marrow infusion. Our data show a rapid induction of an engraftment defect 1 day after 5-FU, persistence of this defect through day 6, and a recovery by day 12. Experiments using hydroxyurea (which selectively kills cells in the S phase) to determine the cell cycle status indicated that cells that engrafted in post-5-FU marrow were noncycling at days 1, 2, and 12 but cycling at day 6. Post-5-FU bone marrow was also analyzed in vitro by colony assays and its cycling status determined by 3H-thymidine suicide assay. High-proliferative-potential colony-forming cells (HPP-CFCs) and low-proliferative-potential colony-forming cells (LPP-CFCs) decreased rapidly 1 day after 5-FU, with a nadir observed at day 6 for HPP-CFCs and day 2 for LPP-CFCs. By day 12, LPP-CFCs showed a total recovery, but HPP-CFCs were still defective. Significant numbers of HPP-CFCs were cycling, mostly at days 6 and 8 after 5-FU, whereas LPP-CFCs appeared quiescent except at day 2. These results emphasize the importance of timing if post-5-FU marrow is used for gene therapy or marrow transplantation.

Stem cell engraftment strategies

The donor stem cell phenotype and host microenvironment determine the outcome of a stem cell transplant. In a series of transplant studies in syngeneic male to female or congenic Ly5.1/Ly5.2 models in which hosts have received no or minimal irradiation (100 cGy), evidence overwhelmingly supports the concept that syngeneic engraftment is determined by stem cell competition. These approaches can be extended to H-2 mismatched allogeneic mouse combination when antigen pre-exposure and CD40-CD40 ligand antibody blockage are employed. A human trial in patients with resistant neoplasia infusing pheresed blood with 10(8) CD3 cells/kg showed that tumor responses and complete chimerism occur with very low levels of CD34+ cells/kg and that the extent of previous treatment is a critical factor in determining chimerism. A major feature of transplants is the phenotype of the donor stem cell. This phenotype shows dramatic reversible plasticity involving differentiation, adhesion protein expression, and engraftment with cytokine-induced cell-cycle transit. Homing is probably also plastic. Marked fluctuations in engraftment capacity are also seen at different points in marrow circadian rhythm.

Clearance kinetics of CD34+ cells from peripheral blood: an independent predictor of hematologic recovery after high-dose chemotherapy and hematopoietic stem cell transplantation

We measured the concentration of CD34+ cells in peripheral blood (PB) (1/2) h prior to and (1/2), 1, 3, 6, and 12 h following hematopoietic stem cell (HSC) infusion in 34 breast cancer patients treated with high-dose chemotherapy (HDC). The decrease in these concentrations over time enabled us to determine the clearance kinetics of CD34+ cells from PB. The absolute number of CD34+ cells in PB generally peaked at (1/2) h after infusion, then rapidly declined from 1 to 3 h post infusion and continued to fall until 12 h post transplant, but more slowly. In univariate analysis, CD34+cells/kg infused, CFU-GM/kg infused, the CD34+ count at (1/2) h, and the 12-h clearance of CD34+ cells from PB were predictors of hematologic recovery, as were each of the two phases of clearance when the slope was divided into rapid and slow phases (from (1/2) to 3 and from 3 to 12 h post transplant, respectively). We then stratified our population by the number of CD34+ cells/kg infused. In group 1, patients received </=7.5 x 10(6) CD34+ cells/kg; in group 2, >7.5 x 10(6) CD34+ cells/kg. After adjusting for CD34+ cells injected, age, and purged or unpurged graft in multivariate analysis, the 12 h clearance remained a predictor of hematologic recovery in group 1. In addition, the second phase of clearance (from 3 to 12 h after infusion) was an even better predictor than the 12 h clearance. In group 2, however, no statistically significant correlation was observed, even with the number of HSC injected. Results suggest that rapidity of clearance of CD34+cells from PB is an independent indicator of hematologic recovery in patients receiving lower doses of CD34+ cells. When the cell dose injected is over a threshold, PB clearance correlations with hematologic recovery are masked.

The administration of 10 microg/kg granulocyte colony-stimulating factor (G-CSF) alone results in a successful peripheral blood stem cell collection when previous mobilization with chemotherapy and hematopoietic growth factor failed

Some heavily pretreated cancer patients fail to mobilize enough peripheral blood stem cells (PBSC) after stimulation with chemotherapy and hematopoietic growth factors. For these patients the best way to obtain an adequate PBSC collection is unknown. Here we report 6 heavily pretreated cancer patients who failed to mobilize sufficient PBSC after stimulation with chemotherapy and G-CSF 5 microg/kg/day. In these cases, we used G-CSF 10 microg/kg/day alone for six days at least 3 weeks after the last chemotherapy. After three consecutive leukaphereses starting on day 5, five patients had adequate PBSC collections. With 6 days of G-CSF 10 microg/kg/day alone, 2.8 x 10(6) (+/- 1) CD34+ cells/kg were collected. This was significantly higher than the number of CD34+ cells/kg collected after chemotherapy and G-CSF 5 microg/kg 0.3 x 10(6) (+/- 0.1) [P = 0.05]. Four patients received high-dose chemotherapy with PBSC support. Hematologic recovery observed in these patients was as expected. In conclusion, G-CSF 10 microg/kg alone can mobilize progenitor cells into peripheral blood when previous mobilization with chemotherapy and G-CSF 5 microg/kg fails.

[Efficiency of high-dose FEC chemotherapy for the mobilization of hematopoietic stem cells into peripheral blood]

The best regimen for mobilizing hematopoietic stem cells (HSC) into peripheral blood is not yet defined. The efficiency of FEC chemotherapy in the treatment of breast cancer is well established and the effects of FEC on HSC mobilization have been characterized. We tested the feasibility and the toxicity of a high-dose FEC regimen which may improve the mobilizing capacity of conventional FEC. Twenty patients with poor prognosis breast cancer received high-dose FEC and filgrastim 5 micrograms/kg. Three leukaphereses were performed on each patient for 3 consecutive days. Total numbers of CFU-GM and CD34+ cells were assessed, and a retrospective analysis was made. The numbers of CFU-GM/kg and CD34+ cells/kg collected (mean +/- standard error) were respectively 12.2 x 10(5) (+/- 2.4) and 14.6 x 10(6) (+/- 2.5). Extra-hematologic toxicity was negligible. Hematologic recovery after CTCb high-dose chemotherapy and HSC infusion was rapid. High-dose FEC is efficient for collecting HSC in peripheral blood. Extra-hematologic toxicity is weak and hematologic recovery after autograft is normal. Increased dosage of epirubicin and cyclophosphamide could allow a single leukapheresis collection of sufficient HSC from peripheral blood.

Quantification of CD34+ cells mobilized into the peripheral blood predicts the yield of the leukapheresis product and can replace progenitor assays

We reviewed 333 concomitant blood and cytapheresis samples from 101 patients with solid malignancies of various histological cell types. All samples were analyzed for CFU-GM, BFU-E and CD34+ determination. We found a good correlation between progenitor assays CFU-GM and CD34+ determination in the blood and cytapheresis (r = 0.77, p < 0.0001 and r = 0.79, p < 0.0001 respectively). The number of CD34+ cells in the peripheral blood was predictive of the CD34+ yield in the cytapheresis (r = 0.86, p < 0.0001), and we determined that a threshold of 26 CD34+/microliter of blood was sufficient to harvest 10(6) CD34+/kg in a single apheresis. Thirty breast cancer patients received injections of peripheral blood stem cells after the same high-dose chemotherapy. For these patients, we found a significant correlation between the quantity of CD34+ cells or CFU-GM collected and both granulocyte and platelet recovery. In conclusion, there is a very good correlation between CFU-GM assays and CD34+ determination and a good correlation between circulating CD34+ cells and the yield obtained by the cytapheresis. The number of CD34+ cells collected is also significantly correlated with hematological recovery. Because CD34+ quantification is an accurate, fast and inexpensive technique, this can lead to the progressive forsaking of progenitor assays in a clinical setting.

Severe anal condylomata acuminata following high-dose chemotherapy and autologous hematopoietic stem cell transplantation: a case report

We report the case of a 37 years old male patient who developed severe anal condylomata acuminata after high-dose chemotherapy and autologous hematopoietic stem cell transplantation for follicular non-Hodgkin's lymphoma. Anal warts were particularly disabling, refractory to the treatment and finally imposed diversion colostomy. The role of cellular immunodeficiency observed after high-dose chemotherapy and autologous hematopoietic stem cell transplantation as etiology of anal condylomata is discussed.

Transient complete remission of acute lymphoblastic leukemia in relapse after allogeneic bone marrow transplantation induced by donor leukocyte transfusions

We report the case of a young patient with refractory acute lymphoblastic leukemia relapse, after allogeneic bone marrow transplantation, who was treated by donor leukocyte infusions. We observed potent adoptive immunotherapy which produced a cytologic complete remission and total chimeric state. This was of short duration and the patient died of severe graft-versus-host disease. We present a short summary of the literature concerning acute lymphoblastic leukemia and donor leukocyte infusions.

High-dose cytotoxic therapy with autologous bone marrow or peripheral blood progenitor cell transplantation in malignant lymphomas

The present paper is an attempt to assess the efficiency of high-dose cytotoxic therapy followed by autologous bone marrow or peripheral progenitor cell rescue with hematopoietic growth factor support given in a group of 27 patients (16 men, 11 women) at the Department of Hematology of the Mont Godinne University Clinics, mainly in the same interval 1990-1994. The reasons for introducing such a therapy in these patients (6 with Hodgkin's disease, 14 with intermediate or high grade, aggressive non Hodgkin lymphomas and 7 with low grade follicular non Hodgkin lymphomas) were relapse of disease after conventional therapy (11 cases), resistance to initial therapy (5 patients) or because of histologically proven transformation to a more aggressive form (one case); in 10 patients with extended, poor prognosis forms, the procedure was used as part of the first line therapy. The conditioning high dose chemotherapy was given according to various regimens, most of them containing Cyclophosphamide, BCNU and Etoposide, with or without total body irradiation. In 14 patients, bone marrow (BM) graft was used, while peripheral blood progenitor cells (PBPC) were infused in the remaining 13 patients. The number of infused granulocyte-macrophage colony forming units (CFU-GM) ranged between 7,650 and 3,900,000/kg, with a mean value of 461,000/kg. The median time intervals required to reach an absolute neutrophil count > 500/microliter, a platelet count > 50,000/microliter and a hematocrit > 30% were 13 days, 20 days and 23 days respectively. Growth factors (GM-CSF and G-CSF) and PBPC use shortened the time for neutrophil recovery as well as neutropenia-related complications. No procedure-related death was observed and complete remission was achieved in 22 cases (81.4%); after a mean follow-up of 32.6 months, 14 patients (55.5%) are alive and free of disease, while in 7 patients (31% of the complete responders) relapse occurred at an average time interval of 8.2 months since the procedure.

Digital necrosis associated with chronic myeloid leukemia: a rare paraneoplastic phenomenon

We describe the case of a 72-year-old man who developed unilateral digital necrosis, four years after diagnosis of chronic myeloid leukemia (CML). The etiology of this paraneoplastic phenomenon appears multiple. The digital necrosis responded well to an aggressive varied treatment. The unusual association of CML with digital necrosis and the etiology of this rare paraneoplastic complication are discussed.

Hypothyroidism and arthritis during interferon therapy

The development of autoantibodies during interferon therapy is frequent, but clinical symptoms of autoimmune disease are uncommon. We report on a female patient who developed arthritis with strongly positive antinuclear factor (ANA) and autoimmune thyroiditis while being treated with alpha 2b interferon (IFN) for chronic myelocytic leukaemia (CML). The arthritis subsided promptly after discontinuation of IFN and initiation of nonsteroidal anti-inflammatory drugs.

Partial isolation and function of the prostacyclin regulating plasma factor

Rat aortic rings stop producing prostacyclin upon prolonged washing in buffer. This 'exhaustion' is caused by inhibition of cyclo-oxygenase, since these rings still convert cyclic endoperoxides but not arachidonic acid into prostacyclin, and most probably is due to high concentrations of peroxides: it can be accelerated by H2O2 or by interrupting the glutathione cycle, while it is delayed by reduced glutathione. Incubation of exhausted rings in human plasma or in a plasma filtrate restores to some extent prostacyclin formation. This filtrate, in particular from uraemic subjects, also inhibits the H2O2 initiated oxidation of guaiacol by ram seminal vesicle microsomes or horseradish peroxidase. The prostacyclin regulating plasma factor has been partially purified and identified as a stable and very polar molecule of mol. wt. 300-400, able to reactivate prostacyclin generation by exhausted rings. We suggest that one or more low mol. wt. plasma components prolong vascular prostacyclin formation by acting as reducing cofactor for cyclo-oxygenase peroxidase. The main physiological role of this plasma activity is probably to protect the vascular prostacyclin forming system from exhaustion during persistent irritation.