Concentrations Of Mitomycin C Research Articles

Use of Mitomycin C in Dacryocystorhinostomy: A Report by the American Academy of Ophthalmology

To review the literature on the adjuvant use of mitomycin C (MMC) during dacryocystorhinostomy (DCR) in adults with primary nasolacrimal duct obstructions (NLDOs) to determine the efficacy in improving functional and anatomic outcomes with an acceptable level of risk. A literature search conducted in November 2020 and updated in November 2022 yielded 137 articles. Twenty-four articles met the inclusion criteria and were rated for level of evidence by the panel methodologist. Inclusion criteria required controlled studies on the effect of MMC on outcomes of external, endoscopic endonasal, or diode laser-assisted transcanalicular DCR in adults with primary acquired nasolacrimal obstruction with 6 months minimum follow-up and at least 10 participants. Six of the 24 articles were rated level I evidence, 15 level II , and 3 level III. In primary external DCR, MMC significantly improved functional outcomes in 3 of 9 series. In primary endoscopic endonasal DCR, MMC significantly improved functional outcomes in 1 of 9 series. In revision endoscopic endonasal DCR, MMC significantly improved functional success in 1 of 3 series. The use of MMC did not improve outcomes statistically in any diode laser-assisted transcanalicular DCR studies. Concentrations of MMC ranged from 0.05 to 1 mg/ml, with 0.2 mg/ml used most frequently in 12 series, with duration of application ranging from 2 to 30 minutes. Ostium size was significantly larger in MMC groups than in control groups at 6 months after surgery in 4 of 5 reporting studies. However, these larger ostia did not confer higher functional success rates. Reporting of adverse events related to MMC were rare, with delayed cutaneous wound healing reported in 1 of 750 patients. Intraoperative use of MMC in external and endoscopic endonasal DCR has been shown to improve functional and anatomic outcomes compared with controls in some series, but there is no agreement on the recommended concentration or application time for MMC in DCR. The data support that MMC use can result in a larger ostium size, decreased granulation tissue formation, and a decreased number of postoperative nasal debridements compared with controls, but this does not translate into improved functional success. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Effects of cyclophosphamide and mitomycin C on radiation-induced transcriptional biomarkers in human lymphoblastoid cells

Purpose Ionizing radiation (IR)-induced transcriptional changes are considered a potential biodosimetry for dose evaluation and health risk monitoring of acute or chronic radiation exposure. It is crucial to understand the impact of confounding factors on the radiation-responsive gene expressions for accurate and reproducible dose assessment. This study aims to explore the potential influence of exposures to chemotherapeutic agents such as cyclophosphamide (CP) and mitomycin C (MMC) on IR-induced transcriptional biomarkers. Methods The human B lymphoblastoid cells (AHH-1) were exposed to 0, 20, 50, 100, 200 and 500 μg/ml CP or 0, 0.025, 0.05, 0.1 and 1 μg/ml MMC, respectively. The appropriate concentrations of CP and MMC were added for 1 h before irradiation with 0, 2, 4 and 6 Gy of 60Co γ-rays at a dose rate of 1 Gy/min. Cell viability was evaluated by CCK-8 assay. The gene expression responses of 18 radiation-induced transcriptional biomarkers were examined at 24 h after exposures to CP and MMC, respectively. The expression levels of five crucial DNA interstrand crosslinks (ICLs) repair genes were also evaluated. The biodosimetry models were established based on the specific radiation-responsive gene combinations. Results The baseline transcriptional levels of the 18 selected genes were slightly affected by CP treatment in the absence of IR, while the transcript responses to IR could be inhibited as the concentration of CP up to 50 μg/ml. MMC treatment up-regulated the background levels in most radiation-responsive gene expressions. Of 18 genes, only the relative mRNA expression levels of CDKN1A and BBC3 were repressed after treatment with IR and MMC in combination. The relative mRNA level of RAD51 was significantly up-regulated after exposure to CP, while the expression of FANCD2, RAD51 and BLM showed an overall increase in response to MMC treatment. After irradiation, the relative mRNA expression levels of FANCD2, BRCA2 and RAD51 exhibited dose-dependent increases in IR alone and MMC treatment groups. In addition, the biodosimetry models were established using 2-4 radiation-responsive genes based on different radiation exposure scenarios. Conclusion Our findings suggested that IR-induced gene expression changes were slightly affected after exposure to a relatively low concentration of CP and MMC. Gene expression combinations might improve the broad applicability of transcriptional biodosimetry across diverse radiation exposures.

Augmented trabeculectomy - The surgical journey and road trip forward.

Augmented trabeculectomy - The surgical journey and road trip forward.

Mitomycin C enhanced the antitumor efficacy of Rocaglamide in colorectal cancer.

Rocaglamide (ROC), a natural phytochemical isolated from Aglaia species, is a translational inhibitor of de novo c-FLIP synthesis, which relieves the inhibition of c-FLIP dimerization with procasoase-8 and downstream activation. Unfortunately, a lot of cancer cells, especially colorectal cancer cells (CRC), exhibit marked resistance to Rocaglamide-induced cell death. Research has demonstrated that mitomycin C (MMC) has broad-spectrum anti-tumor activity that it can synergize with a wide range of clinical drugs to inhibit tumor growth. The current study investigated whether MMC combined with ROC could sensitize CRC cells with different ROC resistance to apoptosis. HCT116 and HT29, two different CRC cells, were treated with ROC and/or MMC, and the induction of apoptosis, inhibition of cell migration and invasion, arrest of cell cycle, induction of reactive oxygen species, and effects on Bcl-2 family signaling pathway were investigated. The results showed that low concentration of MMC combined with ROC significantly promoted HCT116 and HT29 cell apoptosis and inhibited cell proliferation by downregulating the expression of Bcl-2 and c-FLIP, upregulating the expression of Bax, activating the caspase cascade (involving the mitochondrial apoptosis pathway), arresting cell cycle in G1 phase, and increasing the level of reactive oxygen species (ROS). In addition, the viability and morphology of MRC-5 cells were not significantly affected by the combined treatment with ROC and MMC, indicating its safety. Therefore, it is concluded that the combination treatment of ROC and MMC is a highly effective tumor therapy and may offer a promising therapeutic strategy for the treatment of CRC.

Central Composite Design for Optimization of Mitomycin C-Loaded Quantum Dots/Chitosan Nanoparticles as Drug Nanocarrier Vectors

Cancer is one of the most devastating diseases that leads to a high degree of mortality worldwide. Hence, extensive efforts have been devoted to the development of drug nanocarrier vectors as a potential new cancer treatment option. The main goal of this treatment is to deliver an anticancer medicine successfully and effectively to the patient's cells using non-toxic nanocarriers. Here, we present a drug delivery system to emphasize the optimization of an anticancer drug-loaded formulation using Mitomycin C (MMC) encapsulated in chitosan nanocarrier conjugated with a bioimaging fluorescence probe of Mn:ZnS quantum dots (MMC@CS-Mn:ZnS). Additionally, the Response Surface Methodology (RSM), which uses a quadratic model to forecast the behaviour of the nano-drug delivery system, was used to assess the optimization of encapsulation efficiency. In this investigation, the core points of the Central Composite Design (CCD) model were used with 20 runs and 6 replications. The encapsulation efficiency (EE%) was measured using UV-Vis spectroscopy at 362 nm. The highest EE% is 55.31 ± 3.09 under the optimum parameters of incubation time (105 min), concentration of MMC (0.875 mg/mL), and concentration of nanocarriers (5.0 mg/mL). Physicochemical characterizations for the nanocarriers were accessed using a nanosizer and field-emission scanning electron microscopy (FESEM). Three independent variables for the evaluation of the encapsulation efficiency were used, in which the incubation time, concentration of MMC, concentration of nanocarriers, and correlation for each variable were studied. Furthermore, the MMC drug release efficiency was carried out in four different solution pHs of 5.5, 6.0, 6.5, 7.0, and pH 7.5, and the highest cumulative drug release of 81.44% was obtained in a pH 5.5 release medium, followed by cumulative releases of 68.55%, 50.91%, 41.57%, and 32.45% in release mediums with pH 6.0, pH 6.5, pH 7.0, and pH 7.5. Subsequently, five distinct mathematical models-pseudo-first-order, pseudo-second-order, Hixson-Crowell, Korsmeyer-Peppas, and Higuchi kinetic models-were used to fit all of the drug release data. The Korsmeyers-Peppas model was found to fit it well, highlighting its importance for the log of cumulative drug release proportional to the log of time at the equilibrium state. The correlation coefficient value (R2) was obtained as 0.9527, 0.9735, 0.9670, 0.9754, and 0.9639 for the drug release in pH 5.5, pH 6.0, pH 6.5, pH 7.0, and pH 7.5, respectively. Overall, from the analysis, the as-synthesized MMC nanocarrier (MMC@CS-Mn:ZnS) synergistically elucidates the underlying efficient delivery of MMC and leverages the drug loading efficiency, and all these factors have the potential for the simultaneous curbing of non-muscle invasive bladder cancer reoccurrence and progression when applied to the real-time disease treatment.

Dry eye syndrome model established in rabbits via mitomycin C injection in the lacrimal gland.

To develop a new dry eye syndrome (DES) animal model by injecting mitomycin C (MMC) into the lacrimal glands (LGs) of rabbits evaluated by clinical examinations. A volume of 0.1 mL of MMC solution was injected in the LG and the infraorbital lobe of the accessory LG of rabbits for DES induction. Twenty male rabbits were separated into three groups, the control group, and different concentration of MMC, (MMC 0.25: 0.25 mg/mL or MMC 0.50: 0.5 mg/mL) were tested. Both MMC-treated groups received MMC twice injection on day 0 and day 7. Assessment of DES included changes in tear production (Schirmer's test), fluorescein staining pattern, conjunctival impression cytology, and corneal histological examination. After MMC injection, no obvious changes in the rabbit's eyes were noted by slit-lamp examination. Both the MMC 0.25 and the MMC 0.5 groups revealed decreased tear secretion after injection, and the MMC 0.25 group showed a continuous decrease in tear secretion up to 14 days. Fluorescent staining showed punctate keratopathy in both MMC-treated groups. In addition, both MMC-treated groups demonstrated decreased numbers of conjunctival goblet cells after injection. This model induced decreased tear production, punctate keratopathy, and decreased numbers of goblet cells, which are consistent with the current understanding of DES. Therefore, injecting MMC (0.25 mg/mL) into the LGs is an easy and reliable method to establish a rabbit DES model which can apply in new drug screening.

Subconjunctival Lymphatics Respond to VEGFC and Anti-Metabolites in Rabbit and Mouse Eyes.

PurposeTo characterize and pharmacologically influence subconjunctival lymphatics in rabbit and mouse eyes.MethodsRabbits received subconjunctival injections of trypan blue or fixable fluorescent dextrans. Bleb-related outflow pathways were quantified. Immunofluorescence for vessel-specific markers (lymphatics [podoplanin and LYVE-1] and blood vessels [CD31]) were performed in native rabbit conjunctiva and after fixable fluorescent dextran injection. Vascular endothelial cell growth factor-C (VEGFC) was injected subconjunctivally in rabbits. mRNA and protein were assessed for the above markers using RT-PCR and Western blot. Alternatively, mouse studies used Prox1-tdTomato transgenic reporter mice. Subconjunctival injection conditions included: no injection, balanced salt solution (BSS), VEGFC, 5-fluorouracil (5FU) and two concentrations of mitomycin-C (MMC). Two mouse injection protocols (short and long) with different follow-up times and number of injections were performed. Mouse eyes were enucleated, flat mounts created, and subconjunctival branching and length assessed.ResultsRabbit eyes demonstrated clear bleb-related subconjunctival outflow pathways that were distinct from blood vessels and were without nasal/temporal predilection. Immunofluorescence against vessel-specific markers showed lymphatics and blood vessels in rabbit conjunctiva, and these lymphatics overlapped with bleb-related subconjunctival outflow pathways. Subconjunctival VEGFC increased lymphatic (P = 0.004–0.04) but not blood vessel (P = 0.77–0.84) mRNA or protein in rabbits. Prox1-tdTomato transgenic reporter mice demonstrated natively fluorescent lymphatics. Subconjunctival VEGFC increased murine lymphatic branching and length (P ≤ 0.001–0.004) while antimetabolites (P ≤ 0.001–0.043) did the opposite for the long protocol.DiscussionSubconjunctival lymphatics are pharmacologically responsive to both VEGFC and antimetabolites in two animal models studied using different methodologies. These results may be important for bleb-forming glaucoma surgeries or ocular drug delivery.

Unique Ataxia-Oculomotor Apraxia 2 (AOA2) in Israel with Novel Variants, Atypical Late Presentation, and Possible Identification of a Poison Exon.

AOA2 is a rare progressive adolescent-onset disease characterised by cerebellar vermis atrophy, peripheral neuropathy and elevated serum alpha-fetoprotein (AFP) caused by pathogenic bi-allelic variants in SETX, encoding senataxin, involved in DNA repair and RNA maturation. Sanger sequencing of genomic DNA, co-segregation and oxidative stress functional studies were performed in Family 1. Trio whole-exome sequencing (WES), followed by SETX RNA and qRT-PCR analysis, were performed in Family 2. Sanger sequencing in Family 1 revealed two novel in-frame SETX deletion and duplication variants in trans (c.7009_7011del; p.Val2337del and c.7369_7371dup; p.His2457dup). Patients had increased induced chromosomal aberrations at baseline and following exposure to higher mitomycin-C concentration and increased sensitivity to oxidative stress at the lower mitomycin-C concentration in cell viability test. Trio WES in Family 2 revealed two novel SETX variants in trans, a nonsense variant (c.568C > T; p.Gln190*), and a deep intronic variant (c.5549-107A > G). Intronic variant analysis and SETX mRNA expression revealed activation of a cryptic exon introducing a premature stop codon (p.Met1850Lysfs*18) and resulting in aberrant splicing, as shown by qRT-PCR analysis, thus leading to higher levels of cryptic exon activation. Along with a second deleterious allele, this variant leads to low levels of SETX mRNA and disease manifestations. Our report expands the phenotypic spectrum of AOA2. Results provide initial support for the hypomorphic nature of the novel in-frame deletion and duplication variants in Family 1. Deep-intronic variant analysis of Family 2 variants potentially reveals a previously undescribed poison exon in the SETX gene, which may contribute to tailored therapy development.

Does mitomycin-C concentration have any influence on XEN45 gel stent outcomes in a real-world setting?

To compare the effectiveness and safety of XEN45 implanted with mitomycin-C (MMC) 0.01% versus (vs) XEN45 implanted with MMC 0.02%. Retrospective and single-center study conducted on consecutive patients with open-angle glaucoma or ocular hypertension who underwent XEN45-implant, either alone or in combination with cataract surgery. The primary end-point was the mean change in intraocular pressure (IOP) from baseline to the last follow-up visit. Fifty-five patients (63 eyes) were included. Thirty-seven (58.7%) eyes underwent surgery with MMC 0.01% and 26 (41.3%) ones with MMC 0.02%. In the overall study sample, the mean (standard error) IOP was significantly lowered from 17.6 (0.7) mm Hg at baseline to 12.6 (0.3) mm Hg at month 12. The IOP was significantly lowered from 17.3 (15.4 to 19.2) mm Hg and 17.9 (16.1 to 17.8) mm Hg at baseline to 12.3 (11.3 to 13.3) mm Hg and 13.1 (12.3 to 13.9) mm Hg at month 12 in the MMC 0.01% and MMC 0.02% groups, respectively; p < 0.0001 each. The mean number of ocular-hypotensive medications significantly decreased from 2.1 (1.9 to 2.3) at baseline to 0.2 (0.04 to 0.3) at month 12, p < 0.0001, with no significant differences between MMC 0.01% and MMC 0.02% groups, p = 0.5181. At month 12, 50 (80.6%) eyes had functioning blebs. Regarding safety, 18 (28.6%) eyes have experience adverse events. XEN45, either alone or in combination with cataract surgery, showed a good effectiveness and safety profile. MMC dose had no influence on the IOP lowering, which may support the use of the lowest dose.

Rosemary oil nano-emulsion potentiates the apoptotic effect of mitomycin C on cancer cells in vitro

Purpose: To formulate nano-emulsified rosemary oil (REO/NE) and determine its effect on the anticancer agent, mitomycin C (MC) when used as a carrier for the drug. Methods: The droplet size of REO/NE was markedly enlarged when mixed with MC. The cytotoxicity of the formulations on HeLa and MCF-7 cells was determined using MTT assay. The combination index (CI) values were estimated with CompuSyn software, while apoptosis was determined using DAPI fluorescent dye. Results: Treatment of MCF-7 cells and HeLa cells with REO/NE (1% v:v and 1.33% v:v, respectively) reduced the IC50 of MC 33 and 15 folds, respectively. Under fluorescent microscopy, cells treated with REO/NE+MC had more marked reduction of the nuclear area than MC-treated cells. Conclusion: These results indicate that REO/NE is an efficient carrier for MC since it enhanced MC delivery and increased its effect on the cells through the induction of apoptosis at low concentrations of MC.

The Inhibitory Effect of Capparis Ovata Polysaccharides on Cultured Pterygium Fibroblasts.

Objectives:Pterygium recurrence after removal surgery is an important problem. Polysaccharides obtained from Capparis species have been shown to possess various biological properties, including anti-tumor activity. This study was an investigation of the effect of Capparis ovata polysaccharides on cultured pterygium fibroblasts and a comparison with the effects of mitomycin C (MMC).Methods:Pterygium tissue samples were obtained during excision surgery from 3 patients with primary pterygium, and fibroblasts were isolated. Pterygium fibroblast cultures and L929 cell cultures were treated with different concentrations of MMC and Capparis ovata polysaccharides. Cell proliferation and migration were evaluated.Results:An MTT assay revealed that cell viability decreased with increasing concentrations of Capparis ovata polysaccharides in both cell types. MMC also inhibited the proliferation of both cell types. A scratch-wound assay indicated that both Capparis ovata polysaccharides and MMC molecules reduced proliferation and migration in the pterygium fibroblasts and L929 cells.Conclusion:The in vitro Capparis ovata polysaccharide inhibition of proliferation and migration of pterygium fibroblasts was similar to that of MMC. The results of this study suggested that Capparis ovata polysaccharides may be a valuable candidate drug to treat pterygium.

Does bleb needling augmented by mitomycin C or 5‐fluorouracil share similar efficacy with no antimetabolites?

Dear Editor, We have read the article entitled ‘Needling after trabeculectomy - does augmentation by anti-metabolites provide better outcomes and is Mitomycin C better than 5-Fluoruracil? A systematic review with network meta-analyses’ (Halili et al. 2020) with great interest. The authors had concluded no significant difference in the efficacy of using either mitomycin C (MMC), 5-fluorouracil (5-Fu) or no antimetabolites for bleb needling after trabeculectomy, which most doctors may disagree according to the clinical practice. However, there are a few points that need to be clarified before we can state that MMC or 5-Fu application does not outweigh those without antimetabolite usage. One included article retrospectively compared 26 eyes that underwent needling revisions for trabeculectomy failure (Fagerli, et al. 2003). On the one hand, as the individual data presented in this article, four patients had multiple times of needling after the original trabeculectomy. They received the injection of MMC and 5-Fu subsequently. Instead of excluding these cases or analysing them separately, they had abruptly allocated these cases to the MMC group with the presumption that MMC had a more potent effect than 5-Fu. For the current meta-analysis, the inclusion of these inaccurate data reduced the credibility of comparison. On the other hand, the no antimetabolite group in this article had only three cases. In the current meta-analysis, the authors directly compared 13 cases in the MMC group and 10 cases in the 5-Fu group with the 3 cases without antimetabolite application, as Fagerli et al. did in his article. Comparison between small sample sizes data may lead to considerable bias, to a certain degree. As the random effect model was used, it increased the weight of studies with small sample sizes, which magnified its influence on the meta-analysis results. Therefore, ambiguous application of medication and small sample may lower the value of comparison with the inclusion of this article. Another included research focused on topical application of MMC with microsponge before needling revision (Ghoneim & Abd El Hameed 2011). Compared with no antimetabolite group, topical use of MMC brought about significant efficacy in bleb needling. Based on the study design, although the concentration of MMC can be predetermined, the exposure time will be short as irrigation with the balanced salt solution before needling will wash out the antimetabolites. The doses of MMC were therefore inaccurate, as well. In comparison, for the other articles included, antimetabolite augmentation was accomplished by subconjunctival injection of fixed doses within the study. The duration of the antimetabolic effect was prolonged. Though mentioned in the meta-analysis, such difference in drug administration may introduce inaccuracy in assessing MMC’s antifibrotic impact. Selection bias was seen in the included studies. In retrospective studies, patients were selected for antimetabolite injection based on the severity of bleb failure and the judgement from glaucoma specialists (Fagerli et al. 2003; Kim et al. 2019). Under this consideration, those tend to suffer needling failure may be alleviated by antimetabolites and reach similar IOP control and success rate as those only receive needling and have lower chances of failure. The selection bias may hide the potential difference. For the current meta-analysis, all the studies included for the direct comparison of MMC/5-Fu with no antimetabolites were not robust enough to come up with the conclusion. For this reason, we cannot reasonably compare the application of antimetabolites based on the included studies. To sum up, we thought it with low credibility for the comparison of with/without antimetabolites in the current meta-analysis. In agreement with the authors, we call for more extensive randomized studies on this topic.

Targeted delivery of mitomycin C-loaded and LDL-conjugated mesoporous silica nanoparticles for inhibiting the proliferation of pterygium subconjunctival fibroblasts

Pterygium is a degenerative disease that characterized by excessive fibrovascular proliferation. To reduce the recurrence rate, surgery is the main strategy, in combination with adjacent procedures or adjunctive therapy. One of the most common adjunctive agents, mitomycin C (MMC), is known as an alkylating agent that inhibits fibroblast proliferation but is limitedly applied in pterygium due to various complications. A previous study demonstrated that activated pterygium subconjunctival fibroblasts overexpressed low-density lipoprotein (LDL) receptors. In this study, we designed and synthesized MMC-loaded mesoporous silica nanoparticles conjugated with LDL (MMC@MSNs-LDL) to deliver MMC into activated pterygium fibroblasts in a targeted manner. The MMC loading efficiency was approximately 6%. The cell viability test (CCK-8 assay) revealed no cytotoxicity for the empty carrier MSNs at a concentration of ≤1 mg/ml after administration for 48 h in subconjunctival fibroblasts. Primary pterygium and normal human subconjunctival fibroblasts with or without stimulation by vascular endothelial growth factor (VEGF) were treated as follows: 1) 10 μg/ml MMC@MSNs-LDL for 24 h (MMC concentration: 0.6 μg/ml); 2) 0.2 mg/ml MMC for 5 min then cultured for 24 h after MMC removal; and 3) normal culture without any drug treatment. At 24 h, the anti-proliferative effect of MMC@MSNs-LDL in activated pterygium fibroblasts was similar to that of MMC (cell viability: 46.2 ± 5.5% vs 40.5 ± 1.1%, respectively, P = 0.349). Furthermore, the cytotoxicity of MMC@MSNs-LDL to normal fibroblasts with or without VEGF stimulation was significantly lower than that of traditional MMC (cell viability: 75.6 ± 4.4% vs 36.0 ± 1.5%, respectively, P < 0.001; 84.7 ± 5.5% vs 35.7 ± 1.3%, P < 0.001). The binding of fluorescently labeled MMC@MSNs-LDL in fibroblasts was assessed using confocal fluorescence microscopy. The uptake of targeted nanoparticles in fibroblasts was time dependent and saturated at 6 h. VEGF-activated pterygium fibroblasts showed more uptake of MMC@MSNs-LDL than normal fibroblasts with or without VEGF activation (both P < 0.001). Our data strongly suggest that MMC@MSNs-LDL had an effective antiproliferative role in activated pterygium fibroblasts, with reduced toxicity to normal fibroblasts compared to traditional application of MMC. LDL-mediated drug delivery might have great potential in the management of pterygium recurrence.

Inhibitory Effect of Valsartan on Pterygium Fibroblasts.

Angiotensin receptor blockers (ARBs) were shown to have antifibrotic properties in ocular and systemic diseases. In this study, our aim was to investigate the effect of an angiotensin receptor blocker, valsartan, on pterygium fibroblasts and compare this effect with that of mitomycin C (MMC). Pterygium tissue samples were obtained from 3 patients during surgical excision. Primary cultured pterygium fibroblasts and L929 cell cultures were treated with different concentrations of MMC and valsartan. The cell viability decreased with increasing concentrations of valsartan at 48 hours for both cell types. MMC inhibited the proliferation of both cell types at 48 hours. Both agents significantly decreased the cell migration of the 2 cell types, although it was more prominent in the MMC-treated group. Valsartan inhibited the proliferation and migration of pterygium fibroblasts. The known favorable safety profile of these drugs and the results of this study showing inhibitory effect on pterygium fibroblasts make valsartan a potential therapeutic agent for pterygium treatment.

Intraoperative injection versus sponge-applied mitomycin C during trabeculectomy: One-year study.

Purpose:To determine the safety and efficacy of mitomycin C (MMC) injection versus sponge during trabeculectomy.Methods:It is a prospective analysis of patients who underwent trabeculectomy with MMC and followed up for 1 year, divided into two groups, namely, group 1- injection (n = 21), group 2- sponge (n = 21). The same concentration of MMC was used for both groups. Inclusion criteria were trabeculectomies with MMC for intraocular pressure (IOP) control in eyes with glaucoma (primary + secondary) with a follow-up of 1 year.Results:Mean preoperative IOP in group 1 was 29.00 ± 11.92 mmHg and group 2 was 25.87 ± 11.09 mmHg, which reduced to 12.19 ± 4.03 and 15.56 ± 10.72 mmHg at final visit with P value of 0.0002 and 0.001, respectively. Mean preoperative number of antiglaucoma medications was 2.4 ± 0.87 in group 1 and 2.3 ± 0.96 in group 2, which reduced to 0.38 ± 0.5 and 0.91 ± 0.85 with P value of 0.001 and 0.0003, respectively. The complete success rate was 52.4% in the injection group and 26.1% in the sponge group at end of 1 year. Overall, success rate (complete + qualified) was 90.5% and 87% in group 1 and group 2 at final visit. All major complications were encountered in sponge group. 1 (11.1%) patient developed choroidal detachment and one had malignant glaucoma which got resolved by medical management. 33.3% cases had encapsulated bleb which received bleb needling. 44.4% cases underwent Argon laser suture lysis postoperatively.Conclusion:The MMC injection may be as safe and as effective as conventional sponge application with comparable estimated complete treatment success.

Safety and efficacy of intravesical chemotherapy and hyperthermia in the bladder: results of a porcine study

Background Hyperthermia (heating to 43 °C) activates the innate immune system and improves bladder cancer chemosensitivity. Objective To evaluate the tissue penetration and safety of convective hyperthermia combined with intravesical mitomycin C (MMC) pharmacokinetics in live porcine bladder models using the Combat bladder recirculation system (BRS). Methods Forty 60 kg-female swine were anesthetized and catheterized with a 3-way, 16 F catheter. The Combat device was used to heat the bladders to a target temperature of 43 °C with recirculating intravesical MMC at doses of 40, 80, and 120 mg. Dwell-heat time varied from 30–180 min. Rapid necropsy with immediate flash freezing of tissues, blood and urine occurred. MMC concentrations were measured by liquid chromatography tandem-mass spectrometry. Results The Combat BRS system was able to achieve target range temperature (42–44 °C) in 12 mins, and this temperature was maintained as long as the device was running. Two factors increased tissue penetration of MMC in the bladder: drug concentration, and the presence of heat. In the hyperthermia arm, MMC penetration saturated at 80 mg, suggesting that with heating, drug absorption may saturate and not require higher doses to achieve the maximal biological effect. Convective hyperthermia did not increase the MMC concentration in the liver, heart, kidney, spleen, lung, and lymph node tissue even at the 120 mg dose. Conclusions Convective bladder hyperthermia using the Combat BRS device is safe and the temperature can be maintained at 43 °C. Hyperthermia therapy may increase MMC penetration into the bladder wall but does not result in an increase of MMC levels in other organs.

In vitro genotoxic and antigenotoxic effects of cynarin

Ethnopharmacological relevanceCynarin is an artichoke phytochemical that possesses a variety of pharmacological features including free-radical scavenging and antioxidant activity. The origin of artichoke species appears to be Mediterranean region. Two of these species, globe artichoke (Cynara cardunculus var. scolymus L.) and cardoon (Cynara cardunculus var. altilis DC), are widely cultivated and consumed. This vegetable, as the basis of the mediterranean diet, has been used as herbal medicine for its therapeutic effects since ancient times. Therefore, this study was performed to determine genotoxic and antigenotoxic effects of cynarin against MMC (mitomycin C) and H2O2 (hydrogen peroxide) induced genomic instability using chromosome aberrations (CAs), sister chromatid exchanges (SCEs), micronucleus (MN), and comet assays in human lymphocytes. Materials and methodsLymphocytes obtained from two healthy volunteers (1 male and 1 female) were exposed to different concentrations of cynarin (12–194 μM) alone and the combination of cynarin and MMC (0.60 μM) or cynarin and H2O2 (100 μM, only for comet assay). ResultsCynarin alone did not induce significant genotoxic effect in the CA, SCE (except 194 μM), MN, and comet assays. The combination of some concentrations of cynarin and MMC decreased the frequency of CAs, SCEs and MN induced by MMC. Furthermore, the combination of cynarin and H2O2 reduced all comet parameters at all the concentrations compared to H2O2 alone. While the highest concentrations of cynarin significantly decreased mitotic index (MI), the combination of cynarin and MMC increased the reduction of MI induced by MMC alone. ConclusionAll the results obtained in this study demonstrated that cynarin exhibited antigenotoxic effects rather than genotoxic effects. It is believed that cynarin can act as a potential chemo-preventive against genotoxic agents.

Mass spectrometry-based Shiga toxin identification: A clinical validation

After we published our preliminary study on the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and curated E. coli toxin databases on the identification of E. coli Shiga toxins (Stxs) in the Journal of Proteomics in year 2018, we were encouraged to further refine the method and test clinical isolates. In this study, different concentrations of mitomycin C (MMC) and ciprofloxacin (CF), two common antibiotic/chemotherapy agents capable of stimulating Stx production, were first tested and compared on three reference strains and eight clinical isolates to observe the toxin induction and subsequent identification. Notably, no differences were observed between the two agents other than the concentrations applied. Seventeen more clinical isolates were then tested using fixed MMC and CF concentrations and sample amount. This study confirms that the majority of stx2-positive E. coli strains can be stimulated to produce sufficient toxin for confident identification. This does not occur with stx1-positive E. coli isolates, however, despite the fact that both Stxs can be identified for several isolates without MMC or CF stimulation. Biological significanceStxs, especially Stx2, are very important causes of severe food-borne disease, even death. This study confirms that receptor analogue-based affinity enrichment of Stxs, after MMC or CF treatment of E. coli, is useful for fast and accurate Stx2 identification through LC-MS/MS.

Intravesical radiofrequency induced hyperthermia enhances mitomycin C accumulation in tumour tissue

Introduction: Non-muscle invasive bladder cancer (NMIBC) is a highly recurrent disease with potential progression to muscle invasive disease despite the standard bladder instillations with mitomycin C (MMC) or Bacille Calmette–Guérin immunotherapy. Therefore, alternatives such as radiofrequency-induced chemohyperthermia (RF-CHT) with MMC are being investigated. The mechanism explaining the efficacy of RF-CHT is only partly understood. We examined whether RF-CHT results in higher MMC tissue concentrations as compared to cold MMC instillation.Patients and methods: Prior to a planned transurethral resection of bladder tumour (TURBT), patients with stage Ta NMIBC were allocated to either (1) cold MMC instillation or (2) RF-CHT. After MMC instillation, three biopsies were taken of both normal and tumour tissue. Biopsies were snap-frozen and MMC tissue concentrations were analysed using ultra-performance liquid chromatography.Results: Eleven patients were included of which six received RF-CHT. Ten patients had TaG2-LG/HG papillary tumours at pathology. One patient in the RF-CHT group appeared to be free of malignancy and was excluded from the analysis as no tumour biopsies were available. The median MMC concentration in tumour tissue was higher in the RF-CHT group (median 665.00 ng/g vs. 63.75 ng/g, U = 51.0, p = 0.018). Moreover, in both techniques the MMC concentration was lower in normal tissue compared to tumour tissue. Tissue MMC concentration measurements varied substantially within, and between, different patients from the same group.Conclusion: Intravesical RF-CHT results in higher tumour MMC concentrations vs. cold MMC instillation which contributes to its superior efficacy.

P133 - Intravesical radiofrequency induced hyperthermia results in an increased mitomycin-C concentration in tumor tissue

P133 - Intravesical radiofrequency induced hyperthermia results in an increased mitomycin-C concentration in tumor tissue