TB and interstitial lung disease: a systematic review and meta-analysis

INTRODUCTION

To determine the frequency of TB among patients with interstitial lung diseases (ILDs).

METHODS

We performed a comprehensive search in the PubMed/Medline, EMBASE and Scopus databases up to 1 August 2023 of studies reporting on the prevalence of TB among patients with ILDs.

RESULTS

Twelve studies comprising 3,817 patients with ILD were found: the pooled prevalence of TB among ILD patients was 11.0% (95% CI 5.4-21.0). In the subgroup analysis, the TB rate among patients with silicosis and idiopathic pulmonary fibrosis (IPF) was respectively 35.6% (95% CI 32.6-38.8) and 4.4% (95% CI 3.6-5.3) (P = 0.00). The frequency of TB among ILD patients was higher in high TB burden countries than in low/intermediate-burden countries: 26.3%, 95% CI 17.7-37.3 vs. 4.9%, 95% CI 3.3-7.2; P = 0.00.

CONCLUSIONS

This study shows the frequency of TB among ILD patients. The meta-analysis reveals a significantly increased prevalence of TB among ILD patients with silicosis compared to IPF, and among individuals in high TB burden countries than in those with low/intermediate burden. The study results can help physicians and policymakers make efficient decisions for prompt screening and anti-TB treatment initiation in ILD patients..

Characterization of Radiographic and Molecular Changes in Mouse Brain after FLASH Irradiation

PURPOSE/OBJECTIVE(S)

Despite refinements in treatment platforms such as incorporation of high-resolution imaging and real time motion tracking, the amount of radiation dose delivered safely to a particular tissue type is limited by both tissue intrinsic and extrinsic factors. FLASH radiotherapy (RT), delivery of relatively high radiation dose at dose rates several orders of magnitude higher than that of conventional (CONV) dose-rates, may change that paradigm due to normal tissue sparing characteristics of FLASH RT. Our Radiation Oncology Physics division developed a novel FLASH kV x-ray cabinet system for preclinical laboratory research. Here we utilize this technology to establish optimal radiation parameters for FLASH effect in brain tissue of a murine model. A range of total radiation dose and dose rates that are considered to be within the window for FLASH effect are being investigated. We have identified several measurable and clinically meaningful toxicity outcomes, including radiation necrosis and blood brain barrier integrity, to assess FLASH effects in brain tissue.

MATERIALS/METHODS

A high-capacity rotating anode x-ray tube was implemented for FLASH irradiation, operating at 150 kVp with 0.025 mm Cu added filtration. A custom 3D printed immobilization tool was designed to reproducibly position animals for stereotactic irradiation of the brain. Dose and dose rate measurements were performed with calibrated radiographic film in kV solid water. Conventional dose rate irradiations were delivered using a standard laboratory irradiator (SARRP) operating at the same kVp and filtration. The depth-dose gradients in solid water were compared between the irradiators. Healthy 8-week-old C57BL6J mice were then irradiated with graded doses of FLASH and CONV x-rays (10- 60 Gy) using a single 1-cm wide AP field. Dose was prescribed to the center of the brain, at a depth of 3.25 mm. RT-induced necrosis is being monitored by serial biweekly MR imaging using a 7-T preclinical MRI machine. Histopathological changes will be assessed through H&E staining of harvested brain at 3-months post-irradiation (n = 5 per arm). FITC-Dextran infusion will be performed prior to necropsy to assess blood-brain barrier integrity.

RESULTS

Animal setup for stereotactic FLASH brain irradiation was reproducible to within 0.5mm. Measured dose rates were 75.6 Gy/s for FLASH and 3.8 Gy/min for conventional irradiations. At 5-mm depth in solid water, the PDDs agreed to within 4% between SARRP and FLASH Irradiator. Biweekly T1 post and T2 weighted image acquisition is currently underway. Histology and FITC-Dextran data will be presented when available.

CONCLUSION

We have successfully designed a high-precision platform to study x-ray FLASH effects in mice brain model. Evaluation of dose window for brain FLASH effect and molecular mechanisms of this phenomenon is an important step in the potential translation of FLASH RT for brain irradiation.

A Molecular Approach to Characterize the Effects of Fluence, Fluence Rate and LET on Radiation Damage

PURPOSE/OBJECTIVE(S)

Effects of fluence, fluence rate and LET on radiation damage are not resolved using traditional methods of measuring energy deposited by ionization events. The deficiency led to the use of empirical RBE factors in the clinical applications of particle therapy. The use of ionization dosimetry is similarly challenged when applied to development of radiation treatment at ultrahigh (FLASH) dose rate. This study reports a molecular method using plasmid DNA as a more comprehensive model for radiation dosimetry than ionization measurements.

MATERIALS/METHODS

Aqueous solutions of purified supercoiled plasmid DNA, pUC19 (2686 bp), were prepared at different scavenging conditions and injected into 5x5x1 mm3 wells as detector elements. Irradiated samples were analyzed using base excision repair enzymes (Nth and Fpg) and gel electrophoresis to measure yields for DNA single and double strand breaks (SSB and DSB), and clustered lesions. The low LET characteristics of conventional radiation treatment was modeled using orthovoltage 150 kVp x-rays to deliver 2-110 Gy at 90 and 0.5 Gy/s. Higher LET irradiations in the range of 2 - 14 keV/μm were facilitated by measurements in the pristine Bragg peak region using synchrotron-produced 142.2 MeV protons to deliver dose at 2 - 160 Gy at 600 and 1 Gy/s. The DNA wells were inserted into a solid water equivalent phantom for proton irradiation. Only 4 wells could be positioned in the short Bragg peak region in water (∼ 2 cm). To alleviate the uncertainties due to rapidly varying dose and LET distributions, we innovated the use of a 3% water density (i.e., Styrofoam) medium to extend the Bragg peak region from 2 cm to 20 cm, enabling the placement of 20 well containers.

RESULTS

Quantity and quality of molecular damage in the plasmid DNA model varies with fluence, fluence rate and LET of radiation. At high fluence (> 30 Gy) of low-LET radiations, the yields of DNA SSB and non-DSB clustered lesions depend on the fluence rate. These yields decrease by two times between ultrahigh and conventional dose rate irradiation. At a given fluence and fluence rate, the yields for the formation of DNA DSB and non-DSB clustered lesions increase linearly with LET. The low-density phantom allows significant (∼ 10 folds) increase in the number of sampling points and more accurate sample positioning at specific LET compared to water-equivalent phantom. Monte-Carlo track structure simulation of yields for different DNA lesions is being developed to model the molecular damage. In parallel, approaches to improve the sensitivity of the measurements to dose are being investigated.

CONCLUSION

Our results suggest that a molecular-based approach can be used to differentiate the effects of fluence, fluence rate, and LET on radiation damage. The approach demonstrates the potential to improve on the modeling of radiation effects in biological systems than using measured ionization energy. Correlation of the molecular changes to biological outcome for in vitro and in vivo systems are under investigation.

Preclinical Intraoperative FLASH Radiotherapy

PURPOSE/OBJECTIVE(S)

Intraoperative radiation therapy (IORT) is a method of delivering high radiation doses to an internal target with low dose to adjacent organs. Most organs at risk can often be moved out of the radiation field, so dose is usually limited by in-field vascular and/or nerve structures. It is known that ultra-high (FLASH) dose rate (>40 Gy/s) radiation reduces normal tissue toxicity compared to conventional, while preserving tumor control. We hypothesize that FLASH radiation can increase the dose tolerance of vascular and nerve structures, thus permitting for dose escalation in IORT. Here, we present a novel platform using orthovoltage x-rays to study FLASH effects in preclinical IORT. The experimental setup and dosimetry of the system have been established for FLASH irradiation of the abdominal aorta in rats to investigate dose tolerance.

MATERIALS/METHODS

A 150 kVp rotating anode x-ray source with a 75-kW generator was used to deliver FLASH and conventional irradiation. A 3D printed immobilization platform was designed to reproducibly place a surgically exposed rat abdominal aorta at 55mm SSD. A 3-mm thick lead collimator with a 10mm x 10mm aperture was placed into a flange adapter, which docks into the immobilization platform. Phantom and in vivo dosimetry were performed using both calibrated radiographic film and thermoluminescent dosimeters (TLD). Anesthetized 2-month-old Wistar rats underwent laparotomy to expose the abdomen for irradiation. A 10x12x1 mm3 tungsten plate was placed under the aorta to reduce spinal cord dose. Animals were then docked into the irradiator using the immobilization platform. Radiation dose in the range of 20 - 50 Gy were delivered to the abdominal aorta at FLASH and conventional dose-rates. Following treatment, animals undergo MR angiography every two months for 6 months, at which a histological evaluation of aorta wall will be performed.

RESULTS

The FLASH dose rate measured at the aorta wall in a rat carcass was 49.7 ± 1.2 Gy/s distal to the collimator. Dose measurements between the films and TLDs showed an agreement within ±3%. Positional uncertainty mainly depends on the visual localization of the aorta on the collimator window, which is verified before irradiation. Vertical uncertainty is less than 1 mm, which is important given the rapid dose fall off of the system. Eight animals went successfully through the procedure, are healthy and currently being follow up with MR angiography. More animals are being treated for meaningful statistical results. MR angiography and IORT are performed on different days to avoid longer times under anesthesia, which initially resulted on mortality. Results of the MR angiography and histological analysis will be presented.

CONCLUSION

The proposed platform has been successfully utilized for precision setup for FLASH IORT in a preclinical laboratory setting. Evaluation of FLASH effects in IORT setup will be an important step in the potential translation of FLASH IORT, where only one high-dose fraction can be delivered.

Current State of Private Practice and Academic Interventional Radiology: Differences in Practice Structure, Case Mix, and Productivity

PURPOSE

To investigate whether private practice interventional radiology (IR) groups self-report higher overall productivity given differing case mix and more diagnostic radiology interpretation.

MATERIALS AND METHODS

A 60-question survey was distributed to 3,159 self-identified US IR physicians via the Society of Interventional Radiologists member search engine, with 357 responses (11.3% response rate). Of these responses, there were 258 unique practices from 34 US states.

RESULTS

Out of 84 IR group responses, private practice IR (PPIR) physicians reported a minimal trend for higher annual work relative value units (wRVUs) per clinical full-time equivalent compared with academic IR physicians (8,000 versus 7,140, P = .202), but this did not reach statistical significance. PPIR groups reported fewer median weekly hours (50 versus 52), more frequent call (every 6 versus every 5 days), and significantly higher median tenured compensation ($573,000 versus $451,000, P = .000). Out of 179 responses, academic practices reported significantly higher case percentages of interventional oncology and complex hepatobiliary intervention (P <.001), and private practices reported significantly higher percentages of musculoskeletal intervention (P < .001) with a nonsignificant trend for stroke or neurologic intervention (P = .010). Private practices reported more wRVUs from the interpretation of diagnostic imaging, at 26% of total wRVU production compared with 7% of total wRVU production for academic practices (P < .001; n = 131).

CONCLUSIONS

Self-reported data from private and academic IR groups suggest minimally higher wRVUs per clinical full-time equivalent among PPIRs with lower weekly work hours, more frequent call, differing case mix, and significantly higher tenured compensation among PPIR groups.

BMI modifies the effect of HDL on outcomes after coronary artery bypass grafting surgery

Background

While the important role of both high-density lipoprotein cholesterol (HDL-C) and body mass index (BMI) in the prognosis of coronary artery disease (CAD) is well known, the impact of BMI on the association between HDL-C and cardiovascular outcomes remains unclear.

Purpose

In this regard, we aimed to investigate whether BMI can modify the correlation between HDL-C levels and outcomes in patients who underwent coronary artery bypass grafting (CABG).

Methods

The present registry-based cohort study included patients who underwent isolated, elective, and first time CABG with 18≤BMI&lt;35 kg/m2. The median follow-up period was 76.62 (75.71–77.52) months. The participants categorized into three groups based on BMI: 18.5≤BMI&lt;25 kg/m2, 25≤BMI&lt;30 kg/m2, and 30≤BMI&lt;35 kg/m2. The Cox proportional hazards models and Restricted Cubic Splines (RCS) in the Cox models were applied to evaluate the association between HDL-C and all-cause mortality and occurrence of major adverse cardio-cerebrovascular events (MACCE) in different BMI categories.

Results

From 2006 to 2016, a total of 17309 patients (73% male, mean age 66.17±9.98) were included. Compared to other groups, diabetes, hypertension, dyslipidemia, and family history of coronary disease were more prevalent in patients with 30≤BMI&lt;35 kg/m2 (P&lt;0.05). Cox proportional hazards models did not show a significant correlation between each 1 mg/dl increase in HDL-C and risk of all-cause mortality and MACCE. In contrast, the results of RCS in the Cox models demonstrated a non-linear relationship between HDL-C and outcomes in patients with 30≤BMI&lt;35 kg/m2, with higher levels of HDL-C, were paradoxically associated with a higher risk of all-cause mortality and MACCE in this BMI category. In the 3D presentation of the association between BMI, HDL-C and all-cause mortality, the highest risk of all-cause mortality was seen in low levels of HDL-C (HDL-C &lt;20 mg/dl) and low or very high levels of BMI.

Conclusions

Very high HDL-C levels could be associated with a higher risk of adverse outcomes after CABG, in patients with 30≤BMI&lt;35 kg/m2. These findings suggest a role of obesity in the function and properties of HDL-C thereby, it seems necessary to consider the concomitant conditions such as BMI when evaluating the risk of cardiovascular events.

Funding Acknowledgement

Type of funding sources: None.

Disparate participation by gender of conference attendants in scientific discussions

One important metric of a radiologist’s visibility and influence is their ability to participate in discussion within their community. The goal of our study was to compare the participation level of men and women in scientific discussions at the annual meeting of the Radiological Society of North America (RSNA). Eleven volunteers collected participation data by gender in 59 sessions (286 presentations) at the 2018 RSNA meeting. Data was analyzed using a combination of Chi-squared, paired Wilcoxon signed-rank and T-test. Of all RSNA professional attendees at the RSNA, 68% were men and 32% were women. Of the 2869 presentations listed in the program, 65% were presented by men and 35% were presented by women. Of the 286 presentations in our sample, 177 (61.8%) were presented by men and 109 (38.1%) were presented by women. Of these 286 presentations, 81 (63%) were moderated by men and 47 (37%) were moderated by women. From the audience, 190 male attendees participated in 134 question-and-answer (Q&A) sessions following presentations and 58 female attendees participated in 52 Q&A sessions (P<0.001). Female attendees who did participate in Q&A sessions talked for a significantly shorter period of time (mean 7.14 ± 17.7 seconds, median 0) compared to male attendees (28.7 ± 29.6 seconds, median 16; P<0.001). Overall, our findings demonstrate that women participated less than men in the Q&A sessions at RSNA 2018, and talked for a shorter period of time. The fact that women were outnumbered among their male peers may explain the difference in behavior by gender.

The Paracrine Function of Mesenchymal Stem Cells in Response to Pulsed Focused Ultrasound

We studied the paracrine function of mesenchymal stem cells (MSCs) derived from various sources in response to pulsed focused ultrasound (pFUS). Human adipose tissue (AD), bone marrow (BM), and umbilical cord (UC) derived MSCs were exposed to pFUS at two intensities: 0.45 W/cm² I_SATA (310 kPa PNP) and 1.3 W/cm² I_SATA (540 kPa PNP). Following pFUS, the viability and proliferation of MSCs were assessed using a hemocytometer and confocal microscopy, and their secreted cytokine profile determined using a multiplex ELISA. Our findings showed that pFUS can stimulate the production of immunomodulatory, anti-inflammatory, and angiogenic cytokines from MSCs which was dependent on both the source of MSC being studied and the acoustic intensity employed. These important findings set the foundation for additional mechanistic and validation studies using this novel noninvasive and clinically translatable technology for modulating MSC biology.

The effect of essential oil of rosemary on eccentric exercise-induced delayed-onset muscle soreness in non-active women

Muscle soreness is a problem associated with physical activities. Recently, the medicinal herbs are strategies to prevent muscle soreness. The present study aims were to determine the effect of rosemary essential oil on the responses of lactate dehydrogenase, creatine kinase (CK), lymphocytes, neutrophils, muscle swelling (MS) and muscle pain (MP) following eccentric leg curl exercise in non-active women. 24 non-active females voluntarily participated in this study and were randomly assigned into three groups: rosemary dose 1 (RD1) (n=8; 0.25 ml), rosemary dose 2 (RD2) (n=8; 0.5 ml) and placebo (n=8; 0.5 ml olive oil). Participants in supplement groups consumed the desire amounts of rosemary essential oil every 8 h per day for 14 days. Then, the eccentric leg curl exercise was performed. The supplementation continued until 72 h after exercise. The serum variables, as well as, MS and MP were measured before, 24, 48 and 72 h after exercise. Data were analysed using repeated measure analysis of variance and P≤0.05 considered as significant. The results showed that rosemary significantly decreases CK in RD2 compared with placebo and RD1 48 h after exercise. There was no other significant difference in other serum variables. In conclusion, the present study showed a beneficial effect of rosemary on 48-h post-exercise serum CK concentration (a muscle damage indicator).

A Study Comparing the Effects of Targeted Intra-Arterial and Systemic Chemotherapy in an Orthotopic Mouse Model of Pancreatic Cancer

Systemic chemotherapy is the first line treatment for patients with unresectable pancreatic cancer, however, insufficient drug delivery to the pancreas is a major problem resulting in poor outcomes. We evaluated the therapeutic effects of targeted intra-arterial (IA) delivery of gemcitabine directly into the pancreas in an orthotopic mouse model of pancreatic cancer. Nude mice with orthotopic pancreatic tumors were randomly assigned into 3 groups receiving gemcitabine: systemic intravenous (IV) injection (low: 0.3 mg/kg and high: 100 mg/kg) and direct IA injection (0.3 mg/kg). Treatments were administered weekly for 2 weeks. IA treatment resulted in a significantly greater reduction in tumor growth compared to low IV treatment. To achieve a comparable reduction in tumor growth as seen with IA treatment, gemcitabine had to be given IV at over 300x the dose (high IV treatment) which was associated with some toxicity. After 2 weeks, tumor samples from animals treated with IA gemcitabine had significantly lower residual cancer cells, higher cellular necrosis and evidence of increased apoptosis when compared to animals treated with low IV gemcitabine. Our study shows targeted IA injection of gemcitabine directly into the pancreas, via its arterial blood supply, has a superior therapeutic effect in reducing tumor growth compared to the same concentration administered by conventional systemic injection.

Adipose tissue-derived mesenchymal stem cells rescue the function of islets transplanted in sub-therapeutic numbers via their angiogenic properties

A significant proportion of islets are lost following transplantation due to hypoxia and inflammation. We hypothesize that adipose tissue-derived mesenchymal stem cells (AD-MSCs) can rescue a sub-therapeutic number of transplanted islets by helping them establish a new blood supply and reducing inflammation. Diabetic mice received syngeneic transplantation with 75 (minimal), 150 (sub-therapeutic), or 225 (therapeutic) islets, with or without 1 × 10⁶ mouse AD-MSCs. Fasting blood glucose (FBG) values were measured over 6 weeks with tissue samples collected for islet structure and morphology (H&E, insulin/glucagon staining). Histological and immunohistochemical analyses of islets were also performed at 2 weeks in animals transplanted with a sub-therapeutic number of islets, with and without AD-MSCs, to determine new blood vessel formation, the presence of pro-angiogenic factors facilitating revascularization, and the degree of inflammation. AD-MSCs had no beneficial effect on FBG values when co-transplanted with a minimal or therapeutic number of islets. However, AD-MSCs significantly reduced FBG values and restored glycemic control in diabetic animals transplanted with a sub-therapeutic number of islets. Islets co-transplanted with AD-MSCs preserved their native morphology and organization and exhibited less aggregation when compared to islets transplanted alone. In the sub-therapeutic group, AD-MSCs significantly increased islet revascularization and the expression of angiogenic factors including hepatocyte growth factor (HGF) and angiopoietin-1 (Ang-1) while also reducing inflammation. AD-MSCs can rescue the function of islets when transplanted in a sub-therapeutic number, for at least 6 weeks, via their ability to maintain islet architecture while concurrently facilitating islet revascularization and reducing inflammation.

Genomic Stability in Syndromic Basal Cell Carcinoma

Basal cell cancers (BCCs) are characterized by upregulation of Hedgehog pathway through loss of PTCH1 or activation of SMO, and SMO inhibitors, such as vismodegib, are effective therapies for advanced BCCs. Although most BCCs are sporadic, rare individuals with basal cell nevus syndrome (BCNS) harbor germline defects in PTCH1 and develop up to hundreds of tumors that are histopathologically indistinguishable from sporadic BCCs. Interestingly, BCNS-BCCs are more responsive to SMO inhibitors than sporadic BCCs, with minimal development of resistance. Given differences in clinical course and therapy response, we sought to characterize BCCs in the setting of BCNS. We found that BCNS individuals with low tumor burden demonstrated significantly fewer UV signature somatic mutations and lower overall somatic mutational load compared to BCNS individuals with high burden, supporting a role of UV exposure in driving BCC development in BCNS individuals. However, compared with sporadic BCCs, BCNS-BCCs have a significantly lower mutational load, lower proportion of UV mutagenesis, increased genomic stability, and harbor fewer functionally resistant SMO mutations at baseline, explaining why BCNS-BCCs lack intrinsic resistance to SMO inhibitors. BCNS-BCCs appear to have reduced mutator phenotype compared with sporadic BCCs, which may contribute to their relatively more indolent clinical course and responsiveness to therapy.

IFNγ-Dependent Tissue-Immune Homeostasis Is Co-opted in the Tumor Microenvironment

Homeostatic programs balance immune protection and self-tolerance. Such mechanisms likely impact autoimmunity and tumor formation, respectively. How homeostasis is maintained and impacts tumor surveillance is unknown. Here, we find that different immune mononuclear phagocytes share a conserved steady-state program during differentiation and entry into healthy tissue. IFNγ is necessary and sufficient to induce this program, revealing a key instructive role. Remarkably, homeostatic and IFNγ-dependent programs enrich across primary human tumors, including melanoma, and stratify survival. Single-cell RNA sequencing (RNA-seq) reveals enrichment of homeostatic modules in monocytes and DCs from human metastatic melanoma. Suppressor-of-cytokine-2 (SOCS2) protein, a conserved program transcript, is expressed by mononuclear phagocytes infiltrating primary melanoma and is induced by IFNγ. SOCS2 limits adaptive anti-tumoral immunity and DC-based priming of T cells in vivo, indicating a critical regulatory role. These findings link immune homeostasis to key determinants of anti-tumoral immunity and escape, revealing co-opting of tissue-specific immune development in the tumor microenvironment.

Effects of Combined Treatment With Arsenic Trioxide and Itraconazole in Patients With Refractory Metastatic Basal Cell Carcinoma

IMPORTANCE

Tumor resistance is an emerging problem for Smoothened (SMO) inhibitor-treated metastatic basal cell carcinoma (BCC). Arsenic trioxide and itraconazole antagonize the hedgehog (HH) pathway at sites distinct from those treated by SMO inhibitors.

OBJECTIVE

To determine whether administration of intravenous arsenic trioxide and oral itraconazole in patients with metastatic BCC is associated with a reduction in GLI1 messenger RNA expression in tumor and/or normal skin biopsy samples.

DESIGN, SETTING, AND PARTICIPANTS

Five men with metastatic BCC who experienced relapse after SMO inhibitor treatment underwent intravenous arsenic trioxide treatment for 5 days, every 28 days, and oral itraconazole treatment on days 6 to 28. Data were collected from April 10 to November 14, 2013. Follow-up was completed on October 3, 2015, and data were analyzed from June 5 to October 6, 2015.

MAIN OUTCOMES AND MEASURES

The primary outcome was the change in messenger RNA levels of the GLI family zinc finger 1 (GLI1) gene (HH-pathway target gene) in biopsy specimens of normal skin or BCC before and after treatment. Secondary objectives were evaluation of tumor response and tolerability.

RESULTS

Of the 5 patients (mean [SD] age, 52 [9] years; age range, 43-62 years), 3 completed 3 cycles of treatment and 2 discontinued treatment early owing to disease progression or adverse events. Adverse effects included grade 2 transaminitis and grade 4 leukopenia with a grade 3 infection. Overall, arsenic trioxide and itraconazole reduced GLI1 messenger RNA levels by 75% from baseline (P < .001). The best overall response after 3 treatment cycles was stable disease in 3 patients.

CONCLUSIONS AND RELEVANCE

Targeting the HH pathway with sequential arsenic trioxide and itraconazole treatment is a feasible treatment for metastatic BCC. Although some patients experienced stable disease for 3 months, none had tumor shrinkage, which may be owing to transient GLI1 suppression with sequential dosing. Continuous dosing may be required to fully inhibit the HH pathway and achieve clinical response.

On the removal of hexavalent chromium from a Class F fly ash

Coarse and fine samples of a Class F fly ash obtained from commercial combustion of Illinois bituminous coal have been exposed to two long-term leaching tests designed to simulate conditions in waste impoundments. ICP-AES analysis indicated that the coarse and fine fly ash samples contained 135 and 171mg/kg Cr, respectively. Measurements by XAFS spectroscopy showed that the ash samples originally contained 5 and 8% of the chromium, respectively, in the hexavalent oxidation state, Cr(VI). After exposure to water for more than four months, the percentage of chromium as Cr(VI) in the fly-ash decreased significantly for the coarse and fine fly-ash in both tests. Combining the XAFS data with ICP-AES data on the concentration of chromium in the leachates indicated that, after the nineteen-week-long, more aggressive, kinetic test on the coarse fly ash, approximately 60% of the Cr(VI) had been leached, 20% had been reduced to Cr(III) and retained in the ash, and 20% remained as Cr(VI) in the ash. In contrast, during the six-month-long baseline test, very little Cr was actually leached from either the coarse or the fine fly-ash (<0.1mg/kg); rather, about 66% and 20%, respectively, of the original Cr(VI) in the coarse and fine fly-ash was retained in the ash in that form, while the remainder, 34% and 80%, respectively, was reduced and retained in the ash as Cr(III). The results are interpreted as indicating that Cr(VI) present in Class F fly-ash can be reduced to Cr(III) when in contact with water and that such chemical reduction can compete with physical removal of Cr(VI) from the ash by aqueous leaching.

Pilot study on the bioactivity of vitamin d in the skin after oral supplementation

Laboratory studies suggest that vitamin D (VD) supplementation inhibits skin carcinogenesis. However, epidemiologic studies report mixed findings in the association between circulating VD levels and skin cancer risk. We conducted a clinical study to determine whether oral cholecalciferol supplementation would exert direct bioactivity in human skin through modulation of the VD receptor (VDR). We enrolled 25 individuals with serum 25-hydroxyvitamin-D levels <30 ng/mL and with skin photodamage to take 50,000 IU of cholecalciferol biweekly for 8 to 9 weeks. Then, we obtained baseline and end-of-study skin biopsies from photodamaged (PD) and photoprotected (PP) skin, and from benign nevi (BN) and tested for mRNA expression of VDR and cytochrome P450-24 (CYP24), and markers of keratinocytic differentiation. High-dose cholecalciferol supplementation significantly elevated circulating levels of 25-hydroxyvitamin-D (P < 0.0001) and 1,25-dihydroxyvitamin-D (P < 0.0001). VDR expression in PD- and PP-skin showed minimum changes after supplementation. CYP24 expression in PD- and PP-skin was increased after supplementation by 186%, P = 0.08, and 134%, P = 0.07, respectively. In BNs from 11 participants, a trend for higher VDR and CYP24 expression was observed (average of 20%, P = 0.08, and 544%, P = 0.09, respectively). Caspase-14 expression at the basal layer in PD skin samples was the only epidermal differentiation marker that was significantly increased (49%, P < 0.0001). High-dose cholecalciferol supplementation raised serum VD metabolite levels concurrently with CYP24 mRNA and caspase-14 levels in the skin. Our findings of significant variability in the range of VDR and CYP24 expression across study samples represent an important consideration in studies evaluating the role of VD as a skin cancer chemopreventive agent.

Smoothened variants explain the majority of drug resistance in basal cell carcinoma

Advanced basal cell carcinomas (BCCs) frequently acquire resistance to Smoothened (SMO) inhibitors through unknown mechanisms. Here we identify SMO mutations in 50% (22 of 44) of resistant BCCs and show that these mutations maintain Hedgehog signaling in the presence of SMO inhibitors. Alterations include four ligand binding pocket mutations defining sites of inhibitor binding and four variants conferring constitutive activity and inhibitor resistance, illuminating pivotal residues that ensure receptor autoinhibition. In the presence of a SMO inhibitor, tumor cells containing either class of SMO mutants effectively outcompete cells containing the wild-type SMO. Finally, we show that both classes of SMO variants respond to aPKC-ι/λ or GLI2 inhibitors that operate downstream of SMO, setting the stage for the clinical use of GLI antagonists.

Abstract 3248: Pilot study on the bioactivity of vitamin D in the skin after oral supplementation

Experimental studies suggest that vitamin D (VD) plays an important role in skin carcinogenesis. In humans, epidemiologic studies have reported mixed findings in the association between circulating vitamin D levels and skin cancer risk. We conducted a pilot clinical study to determine whether oral VD supplementation would exert any bioactivity in human skin. Methods: The study accrued twenty-five healthy individuals with serum 25-hydroxyvitamin D levels &lt;30 ng/mL and with moderate to severe photodamage on the forearms. Participants took 50,000 IU of VD3 capsules twice a week for 8-9 weeks. Baseline and end-of study skin biopsies were obtained from photodamaged (PD) and photoprotected (PP) skin, and benign nevi (BN), when available, for assessment of changes in putative biomarkers of VD activity. Biomarkers evaluated include the mRNA expression of vitamin D receptor (VDR) and cytochrome P450 24 (CYP24) in keratinocytes and available BN. In addition, molecular markers of keratinocytic differentiation (caspase 14 and loricrin protein expression), epidermal thickness, serum levels of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were assessed. Results: High dose VD supplementation significantly elevated the circulating levels of 25-hydroxyvitamin D from 21.6 ± 5.2 to 70.5 ± 18.2 ng/mL (p &lt; 0.0001) and 1,25-dihydroxyvitamin D from 31.1 ± 12.4 to 51.4 ± 13.5 pg/mL (p &lt; 0.0001). VDR expression in PD- and PP-skin showed minimum changes after VD supplementation. CYP24 expression in PD- and PP-skin showed a non-statistically significant increase after VD supplementation (average of 186% increase, p = 0.08, and 134% increase, p=0.07, respectively). Higher VDR and CYP24 expression was observed in BNs collected at post-intervention than that at baseline from eleven participants, but the difference did not reach statistical significance (average of 20% higher, p = 0.08, and 544% higher, p= 0.09, respectively). The large inter-subject variation in VDR and CYP24 expression may have limited the statistical evaluation. The epidermal differentiation markers did not change significantly after VD supplementation with the exception of a 49% increase (p&lt; 0.0001) in caspase 14 expression at the basal layer in PD skin samples. When epidermal thickness was analyzed, the only significant change was identified when the analysis was stratified by the baseline median thickness. Samples with baseline thickness below or equal to the median exhibited a significant increase in thickness at the end of the intervention. Conclusion: The study showed that following effective oral supplementation based on VD serum levels, subtle indicators of increased keratinocytic differentiation and CYP24 activation can be observed. Future studies evaluating the role of VD as a skin cancer chemopreventive agent with biomarker modulation as an endpoint should be considered before larger intervention studies are implemented in at risk populations.

Citation Format: Clara Curiel-Lewandrowski, Jean Tang, Janine Einspahr, Yira Bermudez, Chiu-Hsieh Hsu, Melika Rezaee, Alex Lee, Joe Tangrea, Howard Parnes, David Alberts, H-H. Sherry Chow. Pilot study on the bioactivity of vitamin D in the skin after oral supplementation. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3248. doi:10.1158/1538-7445.AM2014-3248

Non-DSB clustered DNA lesions induced by ionizing radiation are largely responsible for the loss of plasmid DNA functionality in the presence of cisplatin

The combination of cisplatin and ionizing radiation (IR) increases cell toxicity by both enhancing DNA damage and inhibiting repair mechanisms. Although the formation of cluster DNA lesions, particularly double-strand breaks (DSB) at the site of cisplatin-DNA-adducts has been reported to induce cell death, the contribution of DSB and non-DSB cluster lesions to the cellular toxicity is still unknown. Although both lesions are toxic, it is not always possible to measure their frequency and cell survival in the same model system. To overcome this problem, here, we investigate the effect of cisplatin-adducts on the induction of DSB and non-DSB cluster DNA lesions by IR and determine the impact of such lesions on plasmid functionality. Cluster lesions are two or more lesions on opposite DNA strands with a short distance such that error free repair is difficult or impossible. At a ratio of two cisplatin per plasmid, irradiation of platinated DNA in solution with (137)Cs γ-rays shows enhancements in the formation of DNA DSB and non-DSB cluster lesions by factors of 2.6 and 2.1, respectively, compared to unmodified DNA. However, in absolute terms, the yield for non-DSB cluster lesions is far larger than that for DSB, by a factor of 26. Unmodified and cisplatin-modified DNA were irradiated and subsequently transformed into Escherichia coli to give survival curves representing the functionality of the plasmid DNA as a function of radiation dose. Our results demonstrate that non-DSB cluster lesions are the only toxic lesions present at a sufficient frequency to account for the loss of DNA functionality. Our data also show that Frank-DSB lesions are simply too infrequent to account for the loss of DNA functionality. In conclusion, non-DSB cluster DNA damage is known to be difficult to repair and is probably the lesion responsible for the loss of functionality of DNA modified by cisplatin.

Itraconazole and arsenic trioxide inhibit Hedgehog pathway activation and tumor growth associated with acquired resistance to smoothened antagonists

Recognition of the multiple roles of Hedgehog signaling in cancer has prompted intensive efforts to develop targeted pathway inhibitors. Leading inhibitors in clinical development act by binding to a common site within Smoothened, a critical pathway component. Acquired Smoothened mutations, including SMO(D477G), confer resistance to these inhibitors. Here, we report that itraconazole and arsenic trioxide, two agents in clinical use that inhibit Hedgehog signaling by mechanisms distinct from that of current Smoothened antagonists, retain inhibitory activity in vitro in the context of all reported resistance-conferring Smoothened mutants and GLI2 overexpression. Itraconazole and arsenic trioxide, alone or in combination, inhibit the growth of medulloblastoma and basal cell carcinoma in vivo, and prolong survival of mice with intracranial drug-resistant SMO(D477G) medulloblastoma.

Synthesis of wide band gap nanocrystalline NiO powder via a sonochemical method

A sonochemistry-based synthesis method was used to produce nanocrystalline nickel oxide powder with ≈ 20 nm average crystallite diameter from Ni(OH)(2) precursor. Ultrasound waves were applied to the primary solution to intensify the Ni(OH)(2) precipitation. Dried precipitates were calcined at 320°C to form nanocrystalline NiO particles. The morphology of the produced powder was characterized by transmission electron microscopy. Using sonochemical waves resulted in lowering of the size of the nickel oxide crystallites. FT-IR spectroscopy and X-ray diffraction revealed high purity well-crystallized structure of the synthesized powder. Photoluminescence spectroscopy confirmed production of a wide band-gap structure.

Rietveld analysis of the effect of annealing atmosphere on phase evolution of nanocrystalline TiO2 powders

The structural evolution of nanocrystalline TiO2 was studied by X-ray diffraction (XRD) and the Rietveld refinement method (RRM). TiO2 powders were prepared by the sol-gel technique. Post annealing of as-synthesized powders in the temperature range from 500 degrees C to 800 degrees C under air and argon atmospheres led to the formation of TiO2 nanoparticles with mean crystallite size in the range of 37-165 nm, based on the Rietveld refinement results. It was found that the phase structure, composition, and crystallite size of the resulting particles were dependent on not only the annealing temperature, but also the annealing atmosphere. Rietveld refinement of the XRD data showed that annealing the powders under argon atmosphere promoted the polymorphic phase transformation from anatase to rutile. Field emission scanning electron microscopy (FESEM) was employed to investigate the morphology and size of the annealed powders.

Serum level of matrix metalloproteinase-3 in patients with oral lichen planus

BACKGROUND

Oral Lichen planus (OLP) is a chronic lesion of the oral mucosa with unknown origin. Basement membrane changes are common in OLP and may be mediated by proteases such as matrix metalloproteinase (MMPs) and mast cell chymase. The aim of our study was to evaluate the level of serum MMP-3 in OLP com-pared to normal individuals and assess its clinical significance.

METHODS

Thirty four serum samples from patients diagnosed with OLP (12 males, 22 females, age: 42.2±10.8 years) and 34 serum samples from healthy control subjects (11 males, 23 females, age: 42.5±13.3 years) were collected and MMP-3 concentration was measured by ELISA.

RESULTS

The serum MMP-3 level in OLP patients was higher (21.64±24.31 ng/ml) compared with healthy con-trols (16.52±23.63 ng/ml), but showed no statistically significant difference. A statistically significant difference was demonstrated between the two types of OLP, being more pronounced in the erosive/atrophic form 6).

CONCLUSION

The different clinical appearances of OLP are associated with significant differences in MMP-3 serum level.

The Wound Healing Effects of Iloprost in Patients with Buerger's Disease: Claudication and Prevention of Major Amputations

BACKGROUND

This study analyzes the therapeutic effects of intravenous infusion of iloprost in wound healing, healing of the amputation stump wound, improvement in intermittent claudication and prevention of major amputation in patients with Buerger's disease.

METHODS

In a prospective study, 19 patients with known Buerger's disease, received intravenous iloprost infusion, 6 hours per day for 10 days. Iloprost with a dose of 0.5-2 ng/kg/min according to the patients' tolerance and using cardiac monitoring during the whole infusion period was administered for 6 hours/day using saline solution. Patients with larger wounds underwent simultaneous transmetatarsal or Ray amputation of the involved toe(s). All patients were discharged after 10 days. Patients were followed to detect their healing changes.

RESULTS

Nineteen patients, 19-55 years old received 0.5-2 ng/kg/min iloprost intravenously for 6 hours/day for 10 days. During this period, there was relative improvement in resting pain, but no significant amelioration was noticed in wound healing. In a 2 years follow-up, 14 patients showed a complete healing of the amputation stump and increased distance of walking without any pain. Some previous candidates of major amputation did not need amputation anymore. Five patients (26%) did not respond to therapy.

CONCLUSION

Although Buerger's disease patients who were under iloprost therapy, may not show significant changes in wound healing during treatment and at discharge, late results have proved that iloprost infusion is promising in improving wound healing and claudication and preventing major amputations.