Cytokine Syntheses by T-Cell Subsets From Chronic Myeloid Leukemia Patients: Relationship Between Pre-Treatment Levels and Response to Imatinib Therapy

Background

Although T-cell cytokine's role in the long-term control of chronic myeloid leukemia (CML) is well established, previous studies showed contradicting results regarding imatinib (IM) effect on the endogenous T-cell function by IM. The purpose of this study was to determine the relation between the endogenous T-cell function prior to therapy and the degree of response to IM therapy in CP CML. In addition, modulation of the endogenous T-cell function during IM therapy was studied.

Methods

We evaluated Th1 (gamma interferon (IFN-γ)), Th2 (interleukin (IL-4)) and tumor necrosis factor (TNF)-α cytokine synthesis by activated T-cell subsets in 20 patients with newly diagnosed CML in chronic phase (CP CML) using flow cytometry before and during IM therapy compared to patients with IM resistance (IM Res) and healthy donors.

Results

Patients with optimal response (CML OR) to IM demonstrated a lower pre-treatment Th1 cytokine compared to that of healthy donors, and a higher percentage of Th2 and TNF-α producing T cells compared to that of healthy donors, non-optimal responders (CML nOR) and those with IM Res. A shift from Th2 profile to Th1 profile and initial decline of TNF-α producing T cells was detected early during therapy in optimal responders which was coinciding with complete hematological remission with a significant increase in the percentages of CD4+ve/IFN-γ+ve cells (P = 0.01) and a significant drop of in CD8+ve/IL-4+ve T cells (P = 0.04).

Conclusion

We believe that pre-treatment levels of IL-4 and/or TNF-α may have a role in identifying CP CML patients who may respond to IM therapy; however, further investigation is needed.

Goal setting for health behavior change: evidence from an obesity intervention for rural low-income women

INTRODUCTION

Rural, minority populations are disproportionately affected by overweight and obesity and may benefit from lifestyle modification programs that are tailored to meet their unique needs. Obesity interventions commonly use goal setting as a behavior change strategy; however, few have investigated the specific contribution of goal setting to behavior change and/or identified the mechanisms by which goal setting may have an impact on behavior change. Furthermore, studies have not examined goal setting processes among racial/ethnic minorities. Using data from an obesity intervention for predominately minority women in rural North Carolina, this study sought to examine whether intervention participation resulted in working on goals and using goal setting strategies which in turn affected health behavior outcomes. It also examined racial/ethnic group differences in working on goals and use of goal setting strategies.

METHODS

Data came from a community-based participatory research project to address obesity among low-income, predominately minority women in rural North Carolina. A quasi-experimental intervention design was used. Participants included 485 women aged 18 years and over. Intervention participants (n=208) received health information and goal setting support through group meetings and tailored newsletters. Comparison participants (n = 277) received newsletters on topics unrelated to obesity. Surveys assessed physical activity, fruit and vegetable intake, goal-related stage of change, and use of goal setting strategies. Chi squared statistics were used to assess intervention group differences in changes in goal-related stage of change and use of goal setting strategies as well as racial/ethnic group differences in stage of change and use of goal setting strategies at baseline. The causal steps approach of Baron and Kenny was used to assess mediation.

RESULTS

Intervention compared to comparison participants were more likely to move from contemplation to action/maintenance for the goals of improving diet (58% intervention, 44% comparison, p= 0.04) and physical activity (56% intervention, 31% comparison, p ≤ 0.0001). Intervention group differences were not found for moving from precontemplation to a higher category. At baseline, black compared to white participants were more likely to be working on the goals of getting a better education (p < 0.0001), owning a home (p < 0.01), starting a business (p < 0.0001), and improving job skills (p <0.05). For whites only, intervention participants were more likely than comparison participants to move from contemplation to action/maintenance for the goal of improving diet ( p< 0.05). For both blacks (p < 0.05) and whites (p < 0.0001), intervention participants were more likely than comparison participants to move from contemplation to action/maintenance for the goal of increasing physical activity. For all participants, progression in stages of change mediated the intervention effect on physical activity, but not fruit and vegetable intake. The intervention did not reveal an impact on use of goal setting strategies.

CONCLUSIONS

In this sample of low-income, rural women, the intervention's goal setting component influenced behavior change for participants who were contemplating lifestyle changes at baseline. Racial/ethnic group differences in goal setting indicate the need to gain greater understanding of individual, social, and environmental factors that may uniquely have an impact on goal setting, and the importance of tailoring obesity intervention strategies for optimal, sustainable behavior change.

Respiratory syncytial virus increases lung cellular bioenergetics in neonatal C57BL/6 mice

We have previously reported that lung cellular bioenergetics (cellular respiration and ATP) increased in 4-10 week-old BALB/c mice infected with respiratory syncytial virus (RSV). This study examined the kinetics and changes in cellular bioenergetics in ≤ 2-week-old C57BL/6 mice following RSV infection. Mice (5-14 days old) were inoculated intranasally with RSV and the lungs were examined on days 1-10 post-infection. Histopathology and electron microscopy revealed preserved pneumocyte architectures and organelles. Increased lung cellular bioenergetics was noted from days 1-10 post-infection. Cellular GSH remained unchanged. These results indicate that the increased lung cellular respiration (measured by mitochondrial O2 consumption) and ATP following RSV infection is independent of either age or genetic background of the host.

Pathology of Runting in Farmed Saltwater Crocodiles (Crocodylus porosus) in Australia

Extremely poor growth of some individuals within a birth cohort (runting) is a significant problem in crocodile farming. We conducted a pathological investigation to determine if infectious disease is associated with runting in farmed saltwater crocodiles ( Crocodylus porosus) and to look for evidence of other etiologies. In each of 2005 and 2007, 10 normal and 10 runt crocodiles, with an average age of 5.5 months and reared under identical conditions, were sampled. Laboratory testing included postmortem; histological examination of a wide variety of tissues (with quantitation of features that were noted subjectively to be different between groups); hematology; serum biochemistry (total protein, albumin, globulins, total calcium, phosphorus, and iron); bacterial culture of liver and spleen (2005 only); viral culture of liver, thymus, tonsil, and spleen using primary crocodile cell lines (2007 only); and serum corticosterone (2007 only). The only evidence of infectious disease was mild cutaneous poxvirus infection in 45% of normal and 40% of runt crocodiles and rare intestinal coccidia in 5% of normal and 15% of runt crocodiles. Bacterial and viral culture did not reveal significant differences between the 2 groups. However, runt crocodiles exhibited significant ( P < .05) increases in adrenocortical cell cytoplasmic vacuolation and serum corticosterone, decreased production of bone (osteoporosis), and reduced lymphoid populations in the spleen, tonsil, and thymus. Runts also exhibited moderate anemia, hypoalbuminemia, and mild hypophosphatemia. Taken together, these findings suggest an association between runting and a chronic stress response (hyperactivity of the hypothalamic-pituitary-adrenal axis).

Cellular bioenergetics, caspase activity and glutathione in murine lungs infected with influenza A virus

Inhibition of cellular respiration, oxidation of glutathione and induction of apoptosis have been reported in epithelial cells infected in vitro with influenza A virus (IAV). Here, the same biomarkers were investigated in vivo by assessing the lungs of BALB/c mice infected with IAV. Cellular respiration declined on day 3 and recovered on day 7 post-infection. For days 3-5, the rate (mean±SD) of respiration (µMO2min(-1)mg(-1)) in uninfected lungs was 0.103±0.021 (n=4) and in infected lungs was 0.076±0.025 (n=4, p=0.026). Relative cellular ATP (infected/uninfected) was 4.7 on day 2 and 1.07 on day 7. Intracellular caspase activity peaked on day 7. Cellular glutathione decreased by ≥10% on days 3-7. Lung pathology was prominent on day 3 and caspase-3 labeling was prominent on day 5. IAV infection was associated with suppression of cellular respiration, diminished glutathione, and induction of apoptosis. These functional biomarkers were associated with structural changes noted in infected mice.

ANP and BNP responses to dehydration in the one-humped camel and effects of blocking the renin-angiotensin system

The objectives of this study were to investigate and compare the responses of atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) in the circulation of hydrated, dehydrated, and dehydrated losartan - treated camels; and to document the cardiac storage form of B-type natriuretic peptide in the camel heart. Eighteen male camels were used in the study: control or hydrated camels (n = 6), dehydrated camels (n = 6) and dehydrated losartan-treated camels (n = 6) which were dehydrated and received the angiotensin II (Ang II) AT-1 receptor blocker, losartan, at a dose of 5 mg/kg body weight intravenously for 20 days. Control animals were supplied with feed and water ad-libitum while both dehydrated and dehydrated-losartan treated groups were supplied with feed ad-libitum but no water for 20 days. Compared with time-matched controls, dehydrated camels exhibited a significant decrease in plasma levels of both ANP and BNP. Losartan-treated camels also exhibited a significant decline in ANP and BNP levels across 20 days of dehydration but the changes were not different from those seen with dehydration alone. Size exclusion high performance liquid chromatography of extracts of camel heart indicated that proB-type natriuretic peptide is the storage form of the peptide. We conclude first, that dehydration in the camel induces vigorous decrements in circulating levels of ANP and BNP; second, blockade of the renin-angiotensin system has little or no modulatory effect on the ANP and BNP responses to dehydration; third, proB-type natriuretic peptide is the storage form of this hormone in the heart of the one-humped camel.

Bioenergetics of murine lungs infected with respiratory syncytial virus

BACKGROUND

Cellular bioenergetics (cellular respiration and accompanying ATP synthesis) is a highly sensitive biomarker of tissue injury and may be altered following infection. The status of cellular mitochondrial O(2) consumption of the lung in pulmonary RSV infection is unknown.

METHODS

In this study, lung fragments from RSV-infected BALB/c mice were evaluated for cellular O(2) consumption, ATP content and caspase activity. The disease was induced by intranasal inoculation with the RSV strain A2 and lung specimens were analyzed on days 2-15 after inoculation. A phosphorescence O(2) analyzer that measured dissolved O(2) concentration as a function of time was used to monitor respiration. The caspase-3 substrate analogue N-acetyl-asp-glu-val-asp-7-amino-4-methylcoumarin (Ac-DEVD-AMC) was used to monitor intracellular caspases.

RESULTS

O(2) concentration declined linearly with time when measured in a sealed vial containing lung fragment and glucose as a respiratory substrate, revealing its zero-order kinetics. O(2) consumption was inhibited by cyanide, confirming the oxidation occurred in the respiratory chain. Cellular respiration increased by 1.6-fold (p<0.010) and ATP content increased by 3-fold in the first week of RSV infection. Both parameters returned to levels found in uninfected lungs in the second week of RSV infection. Intracellular caspase activity in infected lungs was similar to uninfected lungs throughout the course of disease.

CONCLUSIONS

Lung tissue bioenergetics is transiently enhanced in RSV infection. This energy burst, triggered by the virus or virus-induced inflammation, is an early biomarker of the disease and may be targeted for therapy.

In vitro biocompatibility of calcined mesoporous silica particles and fetal blood cells

Background:

The biocompatibility of two forms of calcined mesoporous silica particles, labeled as MCM41-cal and SBA15-cal, with fetal blood mononuclear cells was assessed in vitro.

Methods and results:

Fetal mononuclear cells were isolated from umbilical cord blood and exposed to 0.5 mg/mL of MCM41-cal or SBA15-cal for several hours. Transmission electron micrographs confirmed the presence of particles in the cytosol of macrophages, neutrophils, and lymphocytes without noticeable damage to the cellular organelles. The particles (especially MCM41-cal) were in close proximity to plasma, and nuclear and mitochondrial membranes. Biocompatibility was assessed by a functional assay that measured cellular respiration, ie, mitochondrial O₂ consumption. The rate of respiration (k_c, in μM O₂ per minute per 10⁷ cells) for untreated cells was 0.42 ± 0.16 (n = 10), for cells treated with MCM41-cal was 0.39 ± 0.22 (n = 5, P > 0.966) and for cells treated with SBA15-cal was 0.44 ± 0.13 (n = 5, P > 0.981).

Conclusion:

The results show reasonable biocompatibility of MCM41-cal and SBA15-cal in fetal blood mononuclear cells. Future studies are needed to determine the potential of collecting fetal cells from a fetus or neonate, loading the cells in vitro with therapeutic MCM41-cal or SBA15-cal, and reinfusing them into the fetus or neonate.

SU-D-BRB-05: Small Animal Lung Compliance Imaging: Assessment System for Tissue Sensitivity to Radiation Induced Lung Injury

PURPOSE

Recent clinical trials and animal studies have indicated that the tissue sensitivity to radiation induced lung injury (RILI) may be region- specific. In this study, we propose a new 4D cone beam CT (CBCT) basedcompliance imaging method to measure regional pulmonary function change in precisely irradiated small animal under CBCT guidance on small animal radiation research platform (SARRP) to facilitate our understanding of region-specific tissue sensitivity to RILI.

METHODS

Four Sprague-Dawley rats underwent prospective pressure gated 4D CBCT on SARRP. Three animals were selected as control group which underwent a second 4D CBCT scan. The fourth animal was irradiated in the central lung (24 Gy) using 3 × 3 mm collimating cone 2 months prior to the scan. The specific compliance (Csp) was calculated via the real time pressure measurement from the ventilator and displacement field from 3D B-spline image registration between the end of inhale and end of exhale phases from the 4D CBCT scan. The 3D Csp maps from the control animal group were mapped to the irradiated animal as a Csp functional atlas for statistical analysis. We alsoevaluated the repeatability of the Csp measurement on a voxel-by-voxel basis.

RESULTS

No significant Csp difference is found after two month of radiation between the irradiated rat (0.22±0.05) and the functional atlas (0.21±0.07). The observation is consistent with previous publications. The averaged linear correlation coefficient between the voxel-by-voxel Csp measurements from initial and repeat scans in control group is 0.98.

CONCLUSIONS

We proposed a method that uses 4D CBCT based compliance imaging to measure region-specific tissue sensitivity of RILI. We compared the irradiated animal two months after radiation with the control group. Our study shows an excellent robustness of the proposed method for regional lung tissue specific compliance measurement. This work was supported in part by UVa George Amorino Pilot Grant.

MO-F-BRCD-02: SBRT (Part 2): Physics and Quality Assurance Updates

The technical advantage of stereotactic body radiation therapy (SBRT) is based upon the ability to deliver a hypofractionated course of heterogeneous dose to a well-defined volume with a rapid fall-off of dose outside the treatment volume. The overall goal is to deliver an ablative dose to the target while minimizing the effects of radiation on the surrounding normal tissue. The major advantage of SBRT is the greater biologically effective dose to the target than that permitted by less conformal, fractionated techniques. In this presentation the established recommendations for quality assurance and safety of SBRT from ACR, ASTRO, and AAPM will be reviewed. The recommendations include establishing an SBRT clinic, equipment and imaging considerations, overview of staffing and personnel qualifications, treatment planning considerations, training, acceptance and commissioning practices, and use of safety checklists. Additionally, a Failure Mode and Effect Analysis (FMEA) for Stereotactic Body Radiation Therapy Delivery is presented. References: 1. Timothy D. Solberg PhD, James M. Balter PhD, Stanley H. Benedict PhD, Benedick A. Fraass PhD, Brian Kavanagh MD, Curtis Miyamoto MD, Todd Pawlicki PhD, Louis Potters MD, Yoshiya Yamada MD, "Quality and safety considerations in stereotactic radiosurgery and stereotactic body radiation therapy" Practical Radiation Oncology (2011)2. Benedict SH, Yenice KM, Followill D, et al., "Stereotactic Body Radiation Therapy: The Report of AAPM Task Group 101" Med Phys. 2010;37:4078- 41013. Potters L, Kavanagh B, Galvin JM, et al. American Society for Therapeutic Radiology and Oncology (ASTRO) and American College of Radiology (ACR) practice guideline for the performance of stereotactic body radiation therapy. Int J Radiat Oncol Biol Phys. 2010;76:326-3324. Julian R. Perks PhD, Sinisa Stanic MD, Robin L Stern PhD, Barbara Henk RN MSN, Marsha S Nelson RN MBA, Rick D Harse RTT, Mathew Mathai BS CMD, James A Purdy PhD, Richard K Valicenti MD MA, Allan D Siefkin MD and Allen M Chen MD, "Failure Mode and Effect Analysis for Stereotactic Body Radiation Therapy Delivery" Int J Radiat Oncol Biol Phys. 2012 (in press) Learning Objectives: 1. Review and understand the ASTRO Recommendations for QA and Safety with SBRT 2. Review and understand the AAPM Task Group Recommendations for SBRT 3. Review and understand a FEMA Analysis of SBRT.

SU-E-J-192: Static Breath-Hold MRI Based Measurement of Change in Pulmonary Function Following a Course of Radiation Therapy

PURPOSE

Radiation Therapy (RT) induced pulmonary function change may depend on the location, underlying function of that lung prior to radiations, radiation dose/fractionation and other factors. We propose to evaluate the radiation induced pulmonary function change using static breath-hold MRI scans with vascular information and 3D deformable image registration which can provide pulmonary function relative to RT dose on a regional basis.

METHODS

A MRI scan pair near the end of inhale and near the end of exhale with breath hold were acquired for one lung cancer patient before RT and 6 months after RT. The patient was treated with SBRT with 55 Gy to PTVs in the right and the left lung respectively. B-spline based vesselness preserving image registration algorithm was applied to register the MRI pair for the calculation of local lung expansion as a measurement of regional pulmonary function (PF). The PF maps before RT and after RT were then mapped to the planning CT using the same algorithm tuned for MRI-CT registration. The pulmonary function change was calculated via the PF ratio between two MRI pairs.

RESULTS

Strong spatial correlation was found between the irradiated lung region and the region with greatly decreased PF. Based on dose and PFC distribution, no strong determinant factor was found for PF lost in the left lung while the right lung shows that all the lung tissue receiving dose larger than 28 Gy will have a decreased PF.

CONCLUSIONS

We demonstrated a method that uses static breath-hold MRI based lung imaging to evaluate radiation induced pulmonary function change which can be applied to study the dose and the pulmonary function change in a regional basis. This work is supported by NIH grant support 1R21CA144063.

SU-E-T-26: Evaluation of New Pre-Treatment In-Air Patient Specific QA Software for TomoTherapy Treatments

PURPOSE

Math Resolutions, LLC, has extended their Dosimetry Check quality assurance software to include TomoTherapy treatments. Data collected from TomoTherapy's MVCT detectors is processed and compared to the planned treatment dose allowing for pre-treatment QA without the use of phantoms and other detectors. This study presents an overview of our experience at the University of Virginia developing, implementing, and verifying this novel QA strategy.

METHODS

Low modulation and high modulation cheese phantom plans as well as patient plans (prostate, GYN, and vertebra) were used to test the Dosimetry Check in-air software. For all evaluations the treatment table was removed from the XML file of each plan using software provided by Accuray and the resulting in-air calibration plan was delivered. The exit detector sinogram was extracted from the machine and imported into Dosimetry Check along with the TomoTherapy calculated planned dose. The fluence maps were reconstructed and used to recalculate the dose.

RESULTS

The percent difference between the planned dose and the dose calculated from the exit detectors by Dosimetry Check ranged between 0.62% for a simple low modulation cheese phantom plan with a cylindrical target to 7.3% for a high modulation 2.5cm prostate plan. The gamma indices reported range from 94.7% to 97.8% <1 over the overall calculation area for the plans tested using a gamma of 3% and 3mm. For the area receiving over 80% of the prescribed dose, the gamma ranged from 80.7% to 92.9% <1.

CONCLUSIONS

The results of our investigation of Math Resolutions' new product in development, Dosimetry Check's pre-treatment in-air QA software, demonstrate that it has the potential be a very useful and practical tool for TomoTherapy QA. Further testing is being performed in which various errors are intentionally introduced in the delivered dose to test the limits of Dosimetry Check's sensitivity. Research Grant from Math Resolutions LLC 01/12/2012-01/11/2013 Math Resolutions’ Dosimetry Check software was given to UVa to assist with evaluating the precision of the product in reconstructing dose from the TomoTherapy exit detector data.

Responses to dehydration in the one-humped camel and effects of blocking the renin-angiotensin system

Our objectives were to compare the levels of circulating electrolytes, hormones, and renal function during 20 days of dehydration in camels versus the level in non-dehydrated camels and to record the effect of blocking angiotensin II AT1 receptors with losartan during dehydration. Dehydration induced significant increments in serum sodium, creatinine, urea, a substantial fall in body weight, and a doubling in plasma arginine vasopressin (AVP) levels. Plasma aldosterone, however, was unaltered compared with time-matched controls. Losartan significantly enhanced the effect of dehydration to reduce body weight and increase serum levels of creatinine and urea, whilst also impairing the rise in plasma AVP and reducing aldosterone levels. We conclude that dehydration in the camel induces substantial increments in serum sodium, creatinine, urea and AVP levels; that aldosterone levels are altered little by dehydration; that blockade of angiotensin II type 1 receptors enhances the dehydration-induced fall in body weight and increase in serum creatinine and urea levels whilst reducing aldosterone and attenuating the rise in plasma AVP.

Measurement of oxygen consumption by murine tissues in vitro

INTRODUCTION

A novel in vitro system was developed to measure O₂ consumption by murine tissues over several hours.

METHODS

Tissue specimens (7-35 mg) excised from male Balb/c mice were immediately immersed in ice-cold Krebs-Henseleit buffer, saturated with 95% O₂:5% CO₂. The specimens were incubated at 37 °C in the buffer, continuously gassed with O₂:CO₂ (95:5). [O₂] was determined as a function of time from the phosphorescence decay rates (1/τ) of Pd(II) meso-tetra-(4-sulfonatophenyl)-tetrabenzoporphyrin. The values of 1/τ were linear with [O₂]: 1/τ=1/τo + kq [O₂]; 1/τo=the decay rate for zero O₂, kq=the rate constant in s⁻¹ μM⁻¹.

RESULTS

NaCN inhibited O₂ consumption, confirming oxidation occurred in the mitochondrial respiratory chain. The rate of respiration in lung specimens incubated in vitro for 3.9≤t≤12.4 h was 0.24±0.03 μM O₂ min⁻¹ mg⁻¹ (mean±SD, n=28). The corresponding rate for the liver was 0.27±0.13 (n=11, t≤4.7 h), spleen 0.28± 0.07 (n=10, t≤5h), kidney 0.34±0.12 (n=7, t≤5h) and pancreas 0.35±0.09 (n=10, t≤4h). Normal tissue histology at hour 5 was confirmed by light and electron microscopy. There was negligible number of apoptotic cells by caspase 3 staining.

DISCUSSION

This approach allows accurate assessment of tissue bioenergetics in vitro.

Biocompatibility of calcined mesoporous silica particles with cellular bioenergetics in murine tissues

A novel in vitro system was developed to investigate the effects of two forms of calcined mesoporous silica particles (MCM41-cal and SBA15-cal) on cellular respiration of mouse tissues. O(2) consumption by lung, liver, kidney, spleen, and pancreatic tissues was unaffected by exposure to 200 μg/mL MCM41-cal or SBA15-cal for several hours. Normal tissue histology was confirmed by light microscopy. Intracellular accumulation of the particles in the studied tissues was evident by electron microscopy. The results show reasonable in vitro biocompatibility of the mesoporous silicas with murine tissue bioenergetics.