Genetic deviation associated with photodynamic therapy in HeLa cell

Photodynamic therapy (PDT) is a method that is used in cancer treatment. The main therapeutic effect is the production of singlet oxygen (¹O₂). Phthalocyanines for PDT produce high singlet oxygen with absorbers of about 600–700 nm.AimIt is aimed to analyze cancer cell pathways by flow cytometry analysis and cancer-related genes with q-PCR device by applying phthalocyanine L1ZnPC, which we use as photosensitizer in photodynamic therapy, in HELA cell line. In this study, we investigate the molecular basis of L1ZnPC's anti-cancer activity.Material methodThe cytotoxic effects of L1ZnPC, a phthalocyanine obtained from our previous study, in HELA cells were evaluated and it was determined that it led to a high rate of death as a result. The result of photodynamic therapy was analyzed using q-PCR. From the data received at the conclusion of this investigation, gene expression values were calculated, and expression levels were assessed using the 2^−∆∆Ct method to examine the relative changes in these values. Cell death pathways were interpreted with the FLOW cytometer device. One-Way Analysis of Variance (ANOVA) and the Tukey-Kramer Multiple Comparison Test with Post-hoc Test were used for the statistical analysis.ConclusionIn our study, it was observed that HELA cancer cells underwent apoptosis at a rate of 80% with drug application plus photodynamic therapy by flow cytometry method. According to q-PCR results, CT values ​​of eight out of eighty-four genes were found to be significant and their association with cancer was evaluated. L1ZnPC is a new phthalocyanine used in this study and our findings should be supported by further studies. For this reason, different analyses are needed to be performed with this drug in different cancer cell lines. In conclusion, according to our results, this drug looks promising but still needs to be analyzed through new studies. It is necessary to examine in detail which signaling pathways they use and their mechanism of action. For this, additional experiments are required.     

Melanoma-targeted photodynamic therapy based on hypericin-loaded multifunctional P123-spermine/folate micelles

Multifunctional P123 micelle linked covalently with spermine (SM) and folic acid (FA) was developed as a drug delivery system of hypericin (HYP). The chemical structures of the modified copolymers were confirmed by spectroscopy and spectrophotometric techniques (UV–vis, FTIR, and ¹H NMR). The copolymeric micelles loading HYP were prepared by solid dispersion and characterized by UV–vis, fluorescence, dynamic light scattering (DLS), ζ potential, and transmission electron microscopy (TEM). The results provided a good level of stability for HYP-loaded P123-SM, P123-FA, and P123-SM/P123-FA in the aqueous medium. The morphology analysis showed that all copolymeric micelles are spherical. Well-defined regions of different contrast allow us to infer that SM and FA were localized on the surface of micelles, and the HYP molecules are located in the core region of micelles. The uptake potential of multifunctional P123 micelle was accessed by exposing the micellar systems loading HYP to two cell lines, B16-F10 and HaCaT. HYP-loaded P123 micelles reveal a low selectivity for melanoma cells, showing significant photodamage for HaCat cells. However, the exposition of B16-F10 cells to Hyp-loaded SM- and FA-functionalized P123 micelles under light irradiation revealed the lowest CC₅₀ values. The interpretation of these results suggested that the combination of SM and FA on P123 micelles is the main factor in enhancing the HYP uptake by melanoma cells, consequently leading to its photoinactivation.     

The antibacterial activity of photodynamic agents against multidrug resistant bacteria causing wound infection

Antimicrobial photodynamic inactivation (aPDI) of multidrug-resistant (MDR) wound pathogens was evaluated with cationic porphyrin derivatives (CPDs). MDR bacterial strains including Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, and Klebsiella pneumoniae were used. The CPDs named PM, PE, PN, and PL were synthesized as a photosensitizer (PS). A diode laser with a wavelength of 655 nm was used as a light source. aPDI of the combinations formed with different energy densities (50, 100, and 150 J/cm²) and PS concentrations (ranging from 3.125 to 600 µM) were evaluated on each bacterial strain. Dark toxicity, cytotoxicity, and phototoxicity were determined on fibroblast cells. In the aPDI groups, survival reductions of up to 5.80 log₁₀ for E. coli, 5.90 log₁₀ for P. aeruginosa, 6.11 log₁₀ for K. pneumoniae, and 6.78 log₁₀ for A. baumannii were obtained. The cytotoxic effect of PL and PM on fibroblast cells was very limited. PN was the type of CPD with the highest dark toxicity on fibroblast cells. In terms of providing broad-spectrum aPDI without or with very limited cytotoxic effect, the best result was observed in aPDI application with PL. The other CPDs need some modifications to show bacterial selectivity for use at 50 µM and above.     

Magnetic resonance imaging gastrography: evaluation of the dark lumen technique compared with conventional gastroscopy in patients with malignant gastric disease

OBJECTIVES: We sought to demonstrate the feasibility of depicting gastric tumors using magnetic resonance imaging (MRI) while applying the dark lumen technique. The findings were correlated with conventional gastroscopy. In addition, we evaluated the screening for lymph nodes and liver metastases during the same session to identify potential tumor spread. MATERIALS AND METHODS: The study included 15 patients with known malignant gastric disease. Conventional gastrointestinal endoscopy was performed in all patients as gold standard. All patients were examined with computed tomography for tumor staging. MRI was performed using 1 L of tap water as oral contrast agent for all protocols. The MRI program included an axial T1-weighted (T1w; 2D-FLASH) sequence, an axial STIR and T2w (TSE) sequence, and 2 postcontrast T1w (3D coronal /2D axial FLASH) sequences using 0.2 mmol/kg gadolinium diethylenetriaminepenta-acetic acid as intravenously injected contrast agent. Qualitative analysis and comparison with conventional gastroscopy were performed. RESULTS: The images obtained with the postcontrast 3D coronal T1w-FLASH sequence were the most suitable in identifying gastric tumors. Complete correlation with conventional gastroscopy was achieved in 80% of the cases and partial correlation in 13% of the cases. The same imaging sequence was also appropriate for the evaluation of lymph nodes. For the identification of liver metastases, the images obtained with the axial postcontrast T1w 2D-FLASH sequence provided a higher diagnostic confidence as compared with other imaging protocols. CONCLUSIONS: Applying the dark lumen technique through MRI is suitable for imaging gastric tumors and has the potential to become a "one-stop shopping" method because of the possibility for lymph node evaluation and screening for metastases during the same session based on the same images.     

Enhancing Therapeutic Effects of Photodynamic Therapy with 5-Aminolevulinic Acid Using Polymeric Iron Chelators

5-Aminolevulinic acid (5-ALA) is commonly used in photodynamic therapy (PDT) and photodiagnosis. 5-ALA is converted into protoporphyrin IX (PpIX), which exerts phototoxicity upon photoirradiation in many kinds of cancer cells [1]. However, it has been suggested that tumoral iron sometimes compromises the PDT effect of 5-ALA by promoting the metabolization of PpIX to the non-phototoxic heme [2]. In this context, inactivating tumoral iron via an iron chelator is expected to improve the accumulation of 5-ALA-induced PpIX in tumors and enhance the therapeutic effect. Indeed, previous studies have successfully enhanced in vitro phototoxicity of 5-ALA using iron chelators including deferoxamine (DFO), which is the clinically approved chelator for iron overload. However, only a few studies reported the promise of such iron chelators in in vivo probably because of insufficient tumor accumulation of the iron chelators, as it is well known that intravenously injected DFO is quickly cleared from the body. In this regard, we recently developed a polymeric iron chelator by conjugating multiple DFO molecules on the side chain of a poly(ethylene glycol)-poly(aspartic acid). The polymeric iron chelator, termed PDFO, showed prolonged blood retention and higher tumor accumulation than conventional DFO through the enhanced permeability and retention effect [3].Here, we investigated the effect of PDFO on the PDT efficiency with 5-ALA hydrochloride. In in vitro study, PDFO as well as DFO decreased the intercellular iron and enhanced the PpIX accumulation and phototoxicity to cancer cells. Importantly, in in vivo study, DFO did not enhance the PDT effect of 5-ALA hydrochloride; however, PDFO exhibited significantly enhanced therapeutic efficacy in subcutaneous tumor models. These results suggest that PDFO could be a promising polymer for enhancing therapeutic efficacy of 5-ALA hydrochloride.     

Quantifying clinical severity of physics errors in high-dose rate prostate brachytherapy using simulations

PURPOSETo quantitatively evaluate through automated simulations the clinical significance of potential high-dose rate (HDR) prostate brachytherapy (HDRPB) physics errors selected from our internal failure-modes and effect analysis (FMEA).METHODS AND MATERIALSA list of failure modes was compiled and scored independently by 8 brachytherapy physicists on a one-to-ten scale for severity (S), occurrence (O), and detectability (D), with risk priority number (RPN) = SxOxD. Variability of RPNs across observers (standard deviation/average) was calculated. Six idealized HDRPB plans were generated, and error simulations were performed: single (N = 1722) and systematic (N = 126) catheter shifts (craniocaudal; -1cm:1 cm); single catheter digitization errors (tip and connector needle-tips displaced independently in random directions; 0.1 cm:0.5 cm; N = 44,318); and swaps (two catheters swapped during digitization or connection; N = 528). The deviations due to each error in prostate D90%, urethra D20%, and rectum D1cm³ were analyzed using two thresholds: 5–20% (possible clinical impact) and >20% (potentially reportable events).RESULTSTwenty-nine relevant failure modes were described. Overall, RPNs ranged from 6 to 108 (average ± 1 standard deviation, 46 ± 23), with responder variability ranging from 19% to 184% (average 75% ± 30%). Potentially reportable events were observed in the simulations for systematic shifts >0.4 cm for prostate and digitization errors >0.3 cm for the urethra and >0.4 cm for rectum. Possible clinical impact was observed for catheter swaps (all organs), systematic shifts >0.2 cm for prostate and >0.4 cm for rectum, and digitization errors >0.2 cm for prostate and >0.1 cm for urethra and rectum.CONCLUSIONSA high variability in RPN scores was observed. Systematic simulations can provide insight in the severity scoring of multiple failure modes, supplementing typical FMEA approaches.     

叶酸受体介导的肿瘤靶向超顺磁性纳米胶束的制备及体外实验

目的探讨叶酸受体介导的两亲聚合物纳米胶束对人肝癌Bel 7402细胞的靶向性，及利用MR仪对其进行监测的可行性。方法制备由叶酸修饰的、载有超顺磁性氧化铁（SPIO）及抗癌药物表阿霉素（DOX）的纳米胶束，将叶酸靶向及非叶酸靶向纳米胶束分别与人肝癌Bel 7402细胞共孵育1h，进行普鲁士蓝染色和流式细胞术观察Bel 7402细胞对叶酸靶向及非叶酸靶向纳米胶束的吸收情况，并体外MRI观察T2WI信号强度变化。结果叶酸靶向纳米胶束与Bel 7402细胞共孵育后普鲁士蓝染色显示细胞内大量铁存在；非叶酸靶向纳米胶束普鲁士蓝染色显示细胞内铁浓度极低。流式细胞术显示叶酸靶向组及非叶酸靶向组的平均荧光强度分别为117．88和46．33，叶酸靶向组约为非叶酸靶向组的2．5倍。体外MRI显示叶酸靶向纳米胶束与Bel 7402细胞共孵育后在T2WI上信号明显降低（SPIO浓度为5、10、20、40和80μg／ml时，信号变化率中位数分别为-5．02％、-23．58％、-45．89％、-70．34％和-92．41％），而非叶酸靶向组在T2WI上信号无明显降低（SPIO浓度为5、10、20、40和80μg／ml时信号变化率中位数分别为-3．77％、-2．16％、-2．18％、-2．74％和-19．77％）。体外竞争抑制实验普鲁士蓝染色显示细胞内铁浓度极低。结论以叶酸修饰的生物可降解聚合物纳米胶束对人肝癌细胞Bel 7402有较好的靶向性，使用临床型MR仪可对其进行监测。     

Cellular inhibition of microtubule assembly by photoactivated sulphonated meso-tetraphenylporphines

This work relates to studies on modes of phototoxicity by sulphonated mesotetraphenylporphines on cultured cells. Toxicity appears to be related to inhibition of microtubule function. Treatment of human cervix carcinoma cells of the line NHIK 3025 incubated for 18 h with meso-tetraphenylporphine sulphonates (TPPSn where n = 2a, 2o or 4) and exposed to light, inhibits multiplication for the first hours after light exposure, a significant fraction of the cells accumulating in mitosis. The maximal number of cells in mitosis after treatment (approximately 20%) is dependent on the fluence but is similar for all three photosensitizers. For the first hours after treatment the mitotic cells were always mainly in metaphase; mainly seen as c-metaphases and three-group metaphases. During this time anaphase and telophase cells were absent or greatly reduced in number. Indirect immunofluorescence staining of beta-tubulin showed that the spindle apparatus of mitotic cells was perturbed in all cases. Results are presented which indicate that photoactivation of TPPSn located on the plasma membrane destroys microtubules in interphase cells and leads to arrest of the cells in mitosis. The localization of the dye which sensitizes the photoinduced perturbation of microtubules is further discussed.     

MRI to detect atherosclerosis with gadolinium-containing immunomicelles targeting the macrophage scavenger receptor.

The ability to specifically image macrophages may enable improved detection and characterization of atherosclerosis. In this study we evaluated the in vitro uptake of gadolinium (Gd)-containing immunomicelles (micelles linked to macrophage-specific antibody), micelles, and standard contrast agents by murine macrophages, and sought to determine whether immunomicelles and micelles improve ex vivo imaging of apolipoprotein E knockout (ApoE KO) murine atherosclerosis. Murine RAW 264.7 macrophages were incubated with Gd-DTPA, micelles, and immunomicelles. Cell pellets were prepared and imaged using a 1.5 T MR system with an inversion recovery spin-echo sequence to determine the in vitro T1 values. Ex vivo analysis of mouse aortas was performed using a 9.4T MR system with a high-spatial-resolution sequence (78x39x78 microm3). The T1 value was significantly decreased in cells treated with micelles compared to Gd-DTPA (P<0.0001), and in cells incubated at 4 degrees C with immunomicelles compared to micelles (P<0.05). Ex vivo MRI signal intensity (SI) was significantly increased by 81% and 20% in aortas incubated with immunomicelles and micelles, respectively. Confocal microscopy demonstrated in vitro and ex vivo uptake of fluorescent immunomicelles by macrophages. Immunomicelles and micelles improve in vitro and ex vivo MR detection of macrophages, and may prove useful in the detection of macrophage-rich plaques.     

依他硝唑纳米粒对乏氧肿瘤细胞辐射增敏作用的研究

目的 制备出具有生物活性并可控制释放的依他硝唑纳米粒,探讨其对乏氧人乳腺癌细胞(MCF-7)和人子宫颈癌细胞(HeLa)的辐射增敏作用。方法 采用复乳溶剂挥发法制备聚乳酸-聚羟基乙酸共聚物(PLGA)包裹的依他硝唑纳米粒,高效液相色谱分析纳米粒的载药率、包封率和模拟体外释药,透射电镜研究纳米粒的形态,激光衍射粒度分析仪检测纳米粒的粒径分布。经乏氧处理的MCF-7和HeLa细胞与依他硝唑纳米粒和药物单体共培养,采用平板克隆形成实验检验其辐射增敏作用。结果 成功制备依他硝唑纳米粒,呈光滑球形,粒径分布在90～190 nm之间,载药率为1.66％,包封率为18.02％,模拟体外释药曲线呈双相,即在爆发释放之后为缓慢释放。同依他硝唑纳米粒和药物单体共培养的乏氧MCF-7和HeLa细胞克隆形成能力照射后明显降低,依他硝唑纳米粒作用更为显著。结论 具有生物活性的依他硝唑从纳米粒中以可控的方式被释放,有效地增加了乏氧肿瘤细胞的辐射敏感性,为辐射增敏剂的临床应用提供了一种新的给药方式。     

中药复方“体复康”对运动性疲劳大鼠脑组织神经肽Y动态变化影响的研究

为了从脑组织神经肽Ｙ水平探索运动性疲劳产生及药物调节的机理，采用ＡＢＣ免疫组织化学法结合图象分析，观察中药复方“体复康”对运动性疲劳大鼠不同脑区神经肽Ｙ的动态变化。结果显示：一定强度（速度由１５ｍ／ｍｉｎ递增至３５ｍ／ｍｉｎ，运动时间为２０至２５ｍｉｎ／ｄ）长期（共７周）运动的大鼠，安静状态下在丘脑室旁核（ＰＶ）、下丘脑背内侧核（ＤＭ）、下丘脑腹内侧核（ＶＭＨ）等核团ＮＰＹ无显著性变化；在此基础上的未次急性运动结束后３小时ＮＰＹ变化尤为明显。中药复方“体复康”对于慢性运动应激过程中ＮＰＹ的调节作用不明显，在急性运动应激中，中药复方对ＮＰＹ的调节在运动结束后３小时尤为明显，且呈双向调节，即在ＰＶ、ＤＭ核团下调，而在ＶＭＨ核团上调，结论：神经肽Ｙ在运动性疲劳大鼠不同脑区呈现不同的动态变化趋势，中药复方“体复康”对ＮＰＹ有双向调节作用。     

Comparison of abdominal MRI with diffusion-weighted imaging to 68Ga-DOTATATE PET/CT in detection of neuroendocrine tumors of the pancreas

Purpose

The aim of the study was to evaluate contrast-enhanced MRI, diffusion-weighted MRI (DW MRI), and ⁶⁸Ga-DOTATATE positron emission tomography (PET)/CT in the detection of intermediate to well-differentiated neuroendocrine tumors (NET) of the pancreas.

Methods

Eighteen patients with pathologically proven pancreatic NET who underwent MRI including DW MRI and PET/CT within 6 weeks of each other were included in this retrospective study. Two radiologists evaluated T2-weighted (T2w), T2w?+?DW MRI, T2w?+?contrast-enhanced T1-weighted (CE T1w) MR images, and PET/CT for NET detection. The sensitivity and level of diagnostic confidence were compared among modalities using McNemar’s test and a Wilcoxon signed rank test. Apparent diffusion coefficients (ADC) of pancreatic NETs and normal pancreatic tissue were compared with Student’s t test.

Results

Of the NETs, 8/23 (34.8 %) and 9/23 (39.1 %) were detected on T2w images by observers 1 and 2, respectively. Detection rates improved significantly by combining T2w images with DW MRI (observer 1: 14/23?=?61 %; observer 2: 15/23?=?65.2 %; p?<?0.05) or CE T1w images (observer 1: 14/23?=?61 %; observer 2: 15/23?=?65.2 %; p?<?0.05). Detection rates of pancreatic NET with PET/CT (both observers: 23/23?=?100 %) were statistically significantly higher than with MRI (p?<?0.05). The mean ADC value of NET (1.02?±?0.26?×?10^?3?mm²/s) was statistically significantly lower than that of normal pancreatic tissue (1.48?±?0.39?×?10^?3?mm²/s).

Conclusion

DW MRI is a valuable adjunct to T2w imaging and comparable to CE T1w imaging in pancreatic NET detection, quantitatively differentiating between NET and normal pancreatic tissue with ADC measurements. ⁶⁸Ga-DOTATATE PET/CT is more sensitive than MRI in the detection of pancreatic NET.     

On the mechanisms of photodynamic action of photosensitizers based on polycationic derivatives of synthetic bacteriochlorin against human lung cancer cells A549 (in vitro study)

BackgroundOne of the tasks of anticancer photodynamic therapy is increasing the efficacy of treatment of cancer nodes with large (clinically relevant) sizes using near-infrared photosensitizers (PS). We study the photodynamic action against A549 human lung cancer cells using PS based on polycationic derivatives of synthetic bacteriochlorin.MethodsThe efficacy and mechanisms of the photodynamic action of PS based on polycationic derivatives of synthetic bacteriochlorin against A549 lung cancer cells were studied in vitro using immunocytochemical and morphological methods.ResultsIt was found that PS based on tetracationic and octacationic derivatives of synthetic bacteriochlorin induce necrosis, apoptosis, decreasing of proliferative and mitotic activity, as well as reducing the number of ALDH1-positive cancer cells with signs of stem cells in A549 human lung cancer cell culture. The IC₅₀ values (concentration of a PS that reduces cells survival by 50%) were about 0.69 μM for tetracationic PS and 0.57 μM for octacationic PS under irradiation at 30 J/cm² while in the “dark” control they were higher than 100 μM for both PSs.ConclusionsPhotosensitizers based on polycationic derivatives of synthetic bacteriochlorin have high phototoxicity against A549 cancer cells caused by the induction of necrosis and apoptosis of cancer cells, including cells with signs of stemness, and a sharp decrease of mitotic and proliferative activity.     

紫杉醇纳米粒对乏氧MCF-7细胞的辐射增敏作用

目的 制备出具有生物活性并可控制释放的紫杉醇纳米粒,探讨其对乏氧人乳腺癌细胞(MCF-7)的辐射增敏作用。方法 采用单乳溶剂挥发法制备聚乳酸-聚羟基乙酸共聚物［Poly (D,L- lactide-co-glycolide),PLGA］包裹的紫杉醇纳米粒,高效液相色谱分析纳米粒的载药率、包封率和模拟体外释药,扫描电镜研究纳米粒的形态。经乏氧处理的MCF-7细胞与紫杉醇纳米粒共培养,通过细胞形态和细胞周期变化来分析从纳米粒中释放出来的紫杉醇的生物活性,采用平板克隆形成实验检验其辐射增敏作用。结果 成功制备出的紫杉醇纳米粒呈光滑球形,粒径分布为200～800 nm,载药率为4.5%,包封率为85.5%,模拟体外释药曲线呈双相,即在暴发释放之后为缓慢释放。同紫杉醇纳米粒共培养的乏氧MCF-7细胞形态发生改变,极性增加,呈梭形,并且G₂期细胞比例升高,克隆形成能力明显降低。结论 本研究证实具有生物活性的紫杉醇从纳米粒中以可控的方式被释放,有效地增加了乏氧MCF-7细胞的辐射敏感性,为辐射增敏剂的临床应用提供了一种新的给药方式。     

Development of Functional Polymers Targeting Tumor-Associated Amino Acid Transporters for Photosensitizer Delivery

Photodynamic therapy (PDT) is a minimally invasive therapeutic modality that has been clinically approved for various cancer treatment [1]. To extend the potential of PDT to various types of cancers, it is important to develop new photosensitizers or drug delivery systems that can accumulate selectively within target tumors. Up to now, tremendous efforts have been devoted to the development of photosensitizers, some of which are already clinically used [2]. In addition to these efforts, recent studies have reported photosensitizers and drug delivery systems targeting specific molecules and environment in malignant tumors [3,4]. For example, we developed functional polymers possessing multiple cyclic RGD peptides in the side chains for photosensitizer delivery to target α_vβ₃ integrins, and this polymer-photosensitizer conjugate selectively accumulate within subcutaneous tumors in mice upon intravenous injection and accomplished appreciable PDT effects [4]. Such studies indicate that active targeting of tumor-associated molecules or environment should be a promising approach to achieve efficient PDT effects without giving unfavorable photochemical damage to normal tissues. In this context, we recently developed functional polymers targeting tumor-associated amino acid transporters [5]. The polymer had multiple amino acid moieties in the side chains and provided multivalent interaction with target amino acid transporters, exerting efficient tumor accumulation after systemic administration. In this study, based on this strategy, we fine-tuned the chemical structure of the polymers targeting tumor-associated amino acid transporters for PDT. In in vitro study, the fine-tuned polymer-photosensitizer conjugate exhibited strong phototoxicity without substantial dark toxicity to cultured cancer cells in an amino acid transporter-selective manner. Even in in vivo study, the polymer-photosensitizer conjugate demonstrated significantly enhanced PDT effect. Our polymers may be promising drug delivery systems for PDT.     

Antibacterial photodynamic therapy with curcumin and Curcuma xanthorrhiza extract against Streptococcus mutans

BackgroundBacteria are becoming increasingly resistant to conventional antibacterial chemotherapy. This has prompted the application of antibacterial photodynamic therapy (aPDT) in bacteria-related diseases due to its excellent biocide effects. However, few studies have attempted to develop a novel photosensitizer based on natural components. The aim of the present study was to compare the aPDT effects of curcumin and Curcuma xanthorrhiza extract (CXE) against Streptococcus mutans.MethodsA planktonic suspension containing an S. mutans strain was treated in three separate groups: aPDT with curcumin, CXE, and a mixture of curcumin and CXE (ratio= 1:1) at concentrations of 0, 10, 10², 10³, and 10⁴ ng/ml. Light irradiation with a center wavelength of 405 nm was applied using an LED (power density of 84.5 mW for 300 s at an energy density of 25.3 J/cm²). The phototoxicity of photosensitizers against S. mutans was investigated using a colony-forming-unit assay. Percentage logarithmic reductions [log₁₀(CFU/ml) values] were analyzed using one-way ANOVA followed by the Tukey test (p < 0.05) and Student’s independent t-test.ResultsThe viability of S. mutans in the presence of curcumin, CXE, and a mixture of these two components was substantially reduced during irradiation with 405 nm light. The phototoxicity of the photosensitizer varied with its solubility and concentration.ConclusionThese preliminary in vitro findings imply that combining curcumin and CXE with a 405 nm LED may be a novel method of applying aPDT. This could be advantageous in preventing and treating dental caries using devices that are readily available in clinics.     

Using a surgical prostate-specific antigen threshold of >0.2 ng/mL to define biochemical failure for intermediate- and high-risk prostate cancer patients treated with definitive radiation therapy in the ASCENDE-RT randomized control trial

PurposeTo compare biochemical failure using a prostate-specific antigen (PSA) threshold of >0.2 ng/mL to that using Phoenix threshold (nadir+2 ng/mL).Methods and MaterialsAndrogen suppression combined with elective nodal and dose-escalated radiation therapy (the ASCENDE-RT trial) is a randomized control trial in which 276 high-risk and 122 intermediate-risk patients were randomized to (1) a standard arm with 12 months of androgen deprivation therapy, pelvic external beam radiation therapy (EBRT) to 46 Gy, and an EBRT boost (dose-escalated EBRT [DE-EBRT]) to 78 Gy, or (2) an experimental arm which substituted a low-dose-rate prostate brachytherapy boost (LDR-PB). The primary endpoint was biochemical progression-free survival (b-PFS) using the Phoenix threshold. In this reanalysis of ASCENDE-RT, the b-PFS using phoenix is compared to the surgical PSA threshold of >0.2 ng/mL.ResultsCompared to nadir+2 ng/mL, the >0.2 ng/mL PSA threshold doubled the number of relapse events from 69 to 139. However, the increase was confined to the DE-EBRT subjects. The 7-year Kaplan-Meier b-PFS after DE-EBRT declined from 76% using nadir+2 ng/mL to 38% using the >0.2 ng/mL threshold (p < 0.001). Among the LDR-PB subset, there was no significant difference in b-PFS; the 7-year Kaplan-Meier b-PFS was 85% (>0.2 ng/mL) versus 88% (nadir+2 ng/mL) (p = 0.319).ConclusionsReplacing Phoenix with a surgical threshold greatly increased biochemical failure after DE-EBRT boost but had no effect after LDR-PB. As a result of this finding, PSA outcomes after surgery or brachytherapy can be directly compared by using the surgical definition of PSA failure. In this context, a brachytherapy boost appears to produce superior b-PFS compared to contemporary surgical series.     

In vitro antibacterial activity and durability of a nano-curcumin-containing pulp capping agent combined with antimicrobial photodynamic therapy

BackgroundConsidering the antibacterial properties of nano-curcumin (nCur) reinforced with antimicrobial photodynamic therapy (aPDT), this study aimed to assess the antibacterial activity and durability of Activa BioActive Base/Liner (ABBL) containing nCur (nCur-ABBL) as a pulp capping agent against Streptococcus mutans, the most common cause of secondary caries.Materials and methodsIn this in vitro experimental study, ABBL discs containing 0.5 %, 1%, 2%, and 5% (w/w) concentrations of nCur were fabricated. After aPDT using light emitting diode (LED) at 435 ± 20 nm wavelength for 5 min, the discs were undergone aging in artificial saliva for 90 days. The antibacterial activity of the discs against S. mutans was evaluated by the disc agar diffusion test, and the number of bacterial colonies present in the biofilm formed on the disc surfaces was counted after 0, 15, 30, and 60 days of aging.ResultsThe maximum growth inhibition zone was noted around the 5% nCur-ABBL discs. Increasing the concentration of nCur from 0.5 % to 5% combined with aPDT significantly decreased the number of S. mutans colonies in the biofilm over time (P < 0.05). nCur-ABBL discs containing 2% and 5% nCur had no difference in antibacterial activity at any time point up to 60 days (P > 0.05).ConclusionAccording to our data, 5% nCur-ABBL revealed the largest growth inhibition zone in S. mutans culture. Moreover, 5% nCur can serve as an excellent ABBL additive in aPDT producer against S. mutans biofilms up to 60 days of aging period.     

Dantrolene and recovery from heat stroke.

Several authors have shown that dantrolene may be effective in the treatment of heat stroke patients. However, the scant data available are still controversial. The aim of this investigation was to establish an animal experimental model for studying the efficacy of this drug both as a prophylactic agent and as a means of hastening the cooling process after heat stroke. Male albino rats were divided into five groups: Sedentary controls (SC), Sedentary+dantrolene (S+D), Exercise controls (EC), and Exercise+dantrolene (E+D, E+D1). The drug (140 mg x kg(-1) body weight) was administered i.v. either prior to subjection to heat stress (40 degrees C) (S+D, E+D) or upon development of heat stroke syndrome (E+D1). In the S+D group, dantrolene administered prior to heat stress (HS) delayed the development of heat stroke by 70%, although colonic temperature (Tc) at the onset of heat stroke was similar to that in group SC (43.0 +/- 0.1 degrees C and 43.2 +/- 0.4 degrees C for S+D and SC, respectively). In E+D animals, dantrolene shortened exercise endurance in the heat by 17.5%, but concomitantly hindered severe Tc rise (40.9 +/- 0.2 degrees C and 40.0 +/- 0.2 degrees C for EC and E+D, respectively). Administration of dantrolene on the development of heat stroke appeared to improve cooling in the exercise group (0.25 degrees C x min(-1) and 0.18 degrees C x min(-1), for the first 1 5 min of cooling, for E+D1 and EC, respectively). The results suggest that dantrolene is effective as a prophylactic agent in sedentary animals only. It also might have application on development of heat stroke. It is hypothesized that the observed rapid cooling is associated with dantrolene's effect on muscle contraction, thus leading to attenuated heat production and peripheral vascular relaxation.