Sonophotolytic degradation of phthalate acid esters in water and wastewater: influence of compound properties and degradation mechanisms

The influence of physicochemical properties on the sonolytic and sonophotolytic degradation of a group of short-chain phthalate acid esters (PAEs) was investigated in this study. A 400 kHz ultrasonic system and a photolytic system at 253.7 nm were employed separately and together, and both pure water and secondary effluent were used as the water matrices. It was found that PAEs with greater hydrophobicity demonstrated more rapid sonolysis and exhibited greater competitiveness in sonochemical reactions in the presence of other compounds. However, although a greater compound hydrophobicity is beneficial for the sonochemical degradation of PAEs, the observed synergy between ultrasound and UV in the sonophotolytic process is reduced owing to the lower accumulation of H₂O₂ in the aqueous phase. For the sonophotolysis of PAEs in secondary effluent, it was found that PAEs with greater hydrophobicity experienced less inhibition or competition from the background organic substances (expressed as TOC). Identification of prominent degradation intermediates of di-n-butyl phthalate (DBP), as a representative PAE, indicated that hydroxylation of the aromatic ring and butyl-scission of the aliphatic chain are the principal degradation mechanisms. The combined process of US/UV produced a greater degree of DBP mineralization than either US or UV alone (17% TOC reduction within 90 min).

Long-term results of a study using individualized planning target volumes for hypofractionated intensity-modulated radiotherapy boost for prostate cancer

Background

This is the final report of a prospective phase I study which evaluated the feasibility, toxicities, and biochemical control in prostate cancer patients treated with a hypofractionated boost utilizing a fiducial marker-based daily image guidance strategy and small patient-specific PTV margins.

Methods

Low- and intermediate-risk prostate cancer patients underwent transperineal ultrasound-guided implantation of three gold fiducial markers and were treated with three-dimensional conformal radiotherapy to 42 Gy (2 Gy/day). During the first nine fractions of treatment, pre- and post-treatment electronic portal imaging was performed to calculate intrafraction prostate motion. Patient-specific PTV margins were derived and a 30 Gy (3 Gy/day) intensity modulated radiotherapy boost was delivered (Total dose = 72 Gy in 31 fractions; EQD2 = 81 Gy, α/β = 1.4).

Results

Thirty-three patients completed treatment and were followed for a median of 7.2 years (range, 1.2 – 9.5). Seven patients (21%) developed Radiation Therapy Oncology Group (RTOG) late grade 2 GI toxicity and 1 patient (3%) developed late grade 2 GU toxicity. No patients developed late grade 3 GI or GU toxicity. To date, nine patients developed PSA relapse according to the Phoenix criteria. The actuarial five, seven and nine year biochemical control (BC) rates were 87% (95% confidence interval: 69–95), 77% (95% confidence interval: 56–89) and 66% (95% confidence interval: 42–82).

Conclusions

Our study demonstrates that the use of prostate fiducial markers in combination with a daily online image guidance protocol permits reduced, patient-specific PTV margins in a hypofractionated treatment scheme. This treatment planning and delivery strategy was well tolerated in the intermediate time frame. The use of very small PTV margins did not result in excessive failures when compared to other radiation regimens of similar radiobiological intensity.

Hypoxia upregulates Rab11-family interacting protein 4 through HIF-1α to promote the metastasis of hepatocellular carcinoma

Hypoxic microenvironment is a powerful driving force for the invasion and metastasis of hepatocellular carcinoma (HCC). Hypoxia-inducible factor 1α (HIF-1α), as a crucial regulator of transcriptional responses to hypoxia, induces the expression of multiple target genes involved in different steps of HCC metastatic process. It is critical to find target genes associated with metastasis under hypoxia for shedding new light on molecular mechanism of HCC metastasis. In this study, we uncovered that hypoxia could induce the upregulation of Rab11-family interacting protein 4 (Rab11-FIP4) and activation of Rab11-FIP4 promoter by HIF-1α. The overexpression of Rab11-FIP4 significantly enhanced the mobility and invasiveness of HCC cells in vitro, also contributed to distant lung metastasis in vivo, whereas silencing of Rab11-FIP4 decreased the ability of migration and invasion in HCC cells in vitro and suppressed lung metastasis in vivo. Rab11-FIP4 facilitated HCC metastasis through the phosphorylation of PRAS40, which was regulated by mTOR. Furthermore, the expression level of Rab11-FIP4 was significantly increased in HCC tissues and high expression of Rab11-FIP4 was closely correlated with vascular invasion and poor prognosis in HCC patients. A markedly positive correlation between the expression of Rab11-FIP4 and HIF-1α was observed in HCC tissues and combination of Rab11-FIP4 and HIF-1α was a more valuable predictor of poor prognosis for HCC patients. In conclusion, Rab11-FIP4 is a target gene of HIF-1α and has a pro-metastatic role in HCC, suggesting that Rab11-FIP4 may be a promising candidate target for HCC treatment.

4DCT Simulation With Synchronized Contrast Injection in Liver SBRT Patients

BACKGROUND/PURPOSE

Delivering stereotactic body radiotherapy for liver metastases remains a challenge because of respiratory motion and poor visibility without intravenous contrast. The purpose of this article is to describe a novel and simple computed tomography (CT) simulation process of integrating timed intravenous contrast that could overcome the uncertainty of target delineation.

METHODS AND RESULTS

The simulation involves two 4-dimensional CT (4DCT) scans. The first scan only encompasses the immediate region of the tumor and surrounding tissue, which reduces the 4DCT scan time so that it can be optimally timed with intravenous contrast injection. The second 4DCT scan covers a larger volume and is used as the primary CT data set for dose calculation, as well as patient setup verification on the treatment unit. The combination of the two 4DCT scans allows us to optimally visualize liver metastases over all phases of the breathing cycle while simultaneously acquiring a long enough 4DCT data set that is suitable for planning and patient setup verification.

CONCLUSION

This simulation technique allows for a better target definition when treating liver metastases, without being invasive.

PATRIOT Trial: Randomized phase II study of prostate stereotactic body radiotherapy comparing 11 versus 29 days overall treatment time

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Background: Stereotactic body radiotherapy (SBRT) for the treatment of prostate cancer is rapidly increasing. Reported regimens differ in time, dose, and fractionation. We report the results of a multicentre, Canadian randomized phase II study to investigate the impact of overall treatment time on quality of life (QOL) and toxicity. Methods: Men with cT1-2b, Gleason <=7, and PSA <= 20 ng/mL prostate cancer were randomly assigned to 40 Gy in 5 fractions delivered every other day (11 days) vs. once per week (29 days) using gantry-based SBRT. QOL was assessed using the Expanded Prostate Cancer Index Composite (EPIC) at baseline, weeks 2, 4, 6, 12, months 6 and 12, then annually. Toxicity was graded according to RTOG Criteria. The primary end point was the proportion of patients with a minimum clinically important change (MCIC) in bowel QOL at any time during the acute (<=12 week) period and was analyzed by Fisher’s exact test with a two-sided p < 0.05 considered significant. MCIC was defined as a decrease in EPIC score of >0.5 standard deviation of the baseline value. ClinicalTrials.gov NCT01423474. Results: 152 men from 3 centres were randomized with a median follow-up of 13.1 months. Baseline characteristics were similar in both arms except for the International Prostate Symptom Score with medians of 4 vs. 7 in the 11 and 29 day groups, respectively (p=0.02). There were significant differences between the 11 and 29 day groups in the proportion of patients with acute MCIC in bowel (90.0% vs. 69.6%, p<0.01) and urinary (95.7% vs. 74.6%, p<0.01) scores, respectively. No differences were found in acute sexual (p=0.38) or hormonal (p=0.48) QOL. Worst acute grade 1, 2, 3 toxicities were 64, 18, 0% vs. 41, 11, 0% (p<0.01) for GI and 38, 32, 1% vs. 30, 34, 3% (p=0.69) for GU in the 11 and 29 day groups, respectively. There were no late grade 3+ GI toxicities. Late grade 3 GU toxicity occurred in 1 vs. 0 patients in the 11 and 29 day arms (p=0.32). Conclusions: Prostate SBRT delivered over 29 days was associated with superior bowel and urinary QOL compared to 11 days in the first 3 months of treatment. There were few severe (grade 3+) toxicities in either group. Follow-up is continuing to compare long-term outcomes. Clinical trial information: NCT01423474.

The genetic diversity of sinipercid fishes based on complete mitochondrial DNA of six sinipercid fishes from different drainages in China

Sinipercids are a group of freshwater perciform fish endemic in East Asia with the majority of species recorded in China. In the present study, we analyzed the organizations of complete mitogenomes of the six sinipercid fish populations from the Yangtze River and the Pearl River systems in China. The proportion of G was relatively low just at 16.2%-16.5% among the fish populations analyzed. The similarity and divergence analysis showed that the populations from different drainages have more sequence similarities than those from different species in the same drainages. The rate of point mutation was 0.39% and a total of 422 variable sites were identified in the 12 protein-coding genes (excluding the ND6) among the four S. scherzeri populations. The analysis of evolutionary relationship showed that the four S. scherzeri populations can be divided into two groups of Yangtze River system and the Pearl River. Overall the data provide significant information for the genetic and evolutionary status of sinipercids upon adapting to different environments, and for genetic conservation and selective breeding of these fish species in fishery and aquaculture.

Atrazine degradation using chemical-free process of USUV: analysis of the micro-heterogeneous environments and the degradation mechanisms

The effectiveness of sonolysis (US), photolysis (UV), and sonophotolysis (USUV) for the degradation of atrazine (ATZ) was investigated. An untypical kinetics analysis was found useful to describe the combined process, which is compatible to pseudo first-order kinetics. The heterogeneous environments of two different ultrasounds (20 and 400 kHz) were evaluated. The heterogeneous distribution of ATZ in the ultrasonic solution was found critical in determining the reaction rates at different frequencies. The presence of NaCl would promote/inhibit the rates by the growth and decline of "salting out" effect and surface tension. The benefits of combining these two processes were for the first time investigated from the aspect of promoting the intermediates degradation which were resistant in individual processes. UV caused a rapid transformation of ATZ to 2-hydroxyatrazine (OIET), which was insensitive to UV irradiation; however, US and USUV were able to degrade OIET and other intermediates through •OH attack. On the other hand, UV irradiation also could promote radical generation via H2O2 decomposition, thereby resulting in less accumulation of more hydrophilic intermediates, which are difficult to degradation in the US process. Reaction pathways for ATZ degradation by all three processes are proposed. USUV achieved the greatest degree of ATZ mineralization with more than 60% TOC removed, contributed solely by the oxidation of side chains. Ammeline was found to be the only end-product in both US and USUV processes.

Degradation of carbamazepine by Fe(II)-activated persulfate process

Experimental studies were conducted to investigate the oxidative degradation of carbamazepine (CBZ), one of the most frequently detected pharmaceuticals in various waters, by Fe(II)-activated persulfate process. Results show that the Fe(2+)/S2O8(2-) process is very effective for the elimination of CBZ and characterized by a two-stage kinetics (a rapid initial decay followed by a retardation stage). CBZ degradation reaction was observed to be pH dependent and the optimum pH is 3.0 in the range of 2.00-7.87. The concentration of Fe(2+) and S2O8(2-) exhibited a noticeable influence on CBZ removal efficiency, where [S2O8(2-)] exerted more significant effects than that of [Fe(2+)]. The optimal molar ratio of CBZ, Fe(2+), and S2O8(2-) is found to be 1:5:40. The effect of various inorganic anions on CBZ removal was also evaluated under the optimal conditions. The anions NO3(-), SO4(2-) and H2PO4(-)caused a negative effect on the performance of this process, while Cl(-) interestingly accelerated CBZ degradation. The higher the Cl(-) concentration, the faster the CBZ decay rate. The intermediates were identified during CBZ degradation with and without the presence of Cl(-). The evolution of intermediates for these two scenarios was compared. The decay pathways of CBZ were proposed accordingly.

Decompressed percutaneous vertebroplasty: a secured bone cement delivery procedure for vertebral augmentation in osteoporotic compression fractures

The purpose of this study was to assess the efficacy of a new assistive procedure for injecting cement in percutaneous vertebroplasty (PV). Percutaneous vertebroplasty is frequently used for treating patients with osteoporotic vertebral compression fractures. However, the leakage of bone cement during PV may lead to serious complications, such as spinal cord compression or pulmonary embolism. Herein we present a secure procedure designed to safely and effectively deliver the bone cement into the vertebral column.

MATERIALS AND METHODS

Thirty-five patients with a total of 50 levels of osteoporotic compression fracture were consecutively recruited for the study. During a routine PV operation, acrylic cement was injected with a simultaneous application of a continuous negative pressure to the contralateral side of the vertebral body. This negative pressure exerts a pulling force that attracts the bone cement to flow within the vertebral body.

RESULTS

With the proposed decompressed PV procedure, cross-filling of the vertebrographies was achieved for all 50 fracture levels, with no paravertebral venous plexus leakage. Three of the 50 levels (6%) exhibited contrast-medium leakage into the intradisc or cortical defect regions. After decompressed cement injection, excellent cross-filling of bone cement deposition was achieved in 38 of the 50 levels (76%; cement cross-filling region >75%), good cross-filling deposition was achieved in 7 levels (14%; cement cross-filling region >50%), deposition was poor in 3 levels (6%; cement cross-filling region <50%), and deposition failed in 2 levels (4%; fixed cement with no sign of cross-filling). Routine postoperative reviews revealed that six fracture levels (12%) had minimal cement leakage, with two leaking into the disc and four into paravertebral cortical defect regions.

CONCLUSIONS

Compared to the reported 20-88% cement leakage rate for the conventional PV procedure, the proposed decompressed PV procedure offers a more secure and effective way to perform cement injection, and reduces the likelihood of cement leakage.

Sonophotolytic degradation of dimethyl phthalate without catalyst: analysis of the synergistic effect and modeling

The merits of the combined process of high-frequency ultrasound (US) and catalyst-free ultraviolet irradiation (UV) have been evaluated in this study by investigating the sonophotolytic degradation of dimethyl phthalate (DMP). A 400 kHz ultrasonic system and a photolytic system at 253.7 nm were employed individually, sequentially and simultaneously to examine the details of the processes. High UV intensities and low pH conditions enhanced the sonophotolytic degradation of DMP and a clear synergy was evident from the combination of the US and UV irradiation with a synergetic index of 2.6. The role of ultrasonically generated hydrogen peroxide was examined qualitatively and quantitatively, and its generation and photo-decomposition were found to be the principal reason for the process synergy. A novel inverted S-curve model was developed and found to successfully describe the process of sonophotolysis and DMP degradation.

When the tumour is not the culprit: avascular necrosis of the hip in a patient with castration-resistant prostate cancer

Avascular necrosis (avn) of the hip is a well-documented side effect of corticosteroid therapy, but it has also been described as a complication of radiation and chemotherapy. Many prostate cancer patients undergo treatment with all three of those therapeutic modalities, and yet reported cases of avn of the hip in prostate cancer patients are rare. Symptoms that might potentially alert physicians to this complication are nonspecific and may be attributed to cancer progression, in particular to progressive bone metastasis.Here, we report on a 79-year-old man diagnosed with castration-resistant prostate cancer whose diagnosis of avn of the hip was confounded by his underlying malignancy. We discuss risk factors and diagnostic clues in this differential diagnosis of acute hip pain in patients with castration-resistant prostate cancer. Physicians might maintain a high index of suspicion for avn of the hip in prostate cancer patients presenting with new-onset hip pain. Surgical intervention may help to prevent the appearance of avn-associated pain and the negative impact of advanced avn on overall quality of life.

Probing early tumor response to radiation therapy using hyperpolarized [1-¹³C]pyruvate in MDA-MB-231 xenografts

Following radiation therapy (RT), tumor morphology may remain unchanged for days and sometimes weeks, rendering anatomical imaging methods inadequate for early detection of therapeutic response. Changes in the hyperpolarized [1-¹³C]lactate signals observed in vivo following injection of pre-polarized [1-¹³C]pyruvate has recently been shown to be a marker for tumor progression or early treatment response. In this study, the feasibility of using ¹³C metabolic imaging with [1-¹³C]pyruvate to detect early radiation treatment response in a breast cancer xenograft model was demonstrated in vivo and in vitro. Significant decreases in hyperpolarized [1-¹³C]lactate relative to [1-¹³C]pyruvate were observed in MDA-MB-231 tumors 96 hrs following a single dose of ionizing radiation. Histopathologic data from the treated tumors showed higher cellular apoptosis and senescence; and changes in the expression of membrane monocarboxylate transporters and lactate dehydrogenase B were also observed. Hyperpolarized ¹³C metabolic imaging may be a promising new tool to develop novel and adaptive therapeutic regimens for patients undergoing RT.