Mesna Improves Outcomes of Sulfur Mustard Inhalation Toxicity in an Acute Rat Model.

Inhalation of high levels of sulfur mustard (SM), a potent vesicating and alkylating agent used in chemical warfare, results in acutely lethal pulmonary damage. Sodium 2-mercaptoethane sulfonate (mesna) is an organosulfur compound that is currently Food and Drug Administration (FDA)-approved for decreasing the toxicity of mustard-derived chemotherapeutic alkylating agents like ifosfamide and cyclophosphamide. The nucleophilic thiol of mesna is a suitable reactant for the neutralization of the electrophilic group of toxic mustard intermediates. In a rat model of SM inhalation, treatment with mesna (three doses: 300 mg/kg intraperitoneally 20 minutes, 4 hours, and 8 hours postexposure) afforded 74% survival at 48 hours, compared with 0% survival at less than 17 hours in the untreated and vehicle-treated control groups. Protection from cardiopulmonary failure by mesna was demonstrated by improved peripheral oxygen saturation and increased heart rate through 48 hours. Additionally, mesna normalized arterial pH and pACO2 Airway fibrin cast formation was decreased by more than 66% in the mesna-treated group at 9 hour after exposure compared with the vehicle group. Finally, analysis of mixtures of a mustard agent and mesna by a 5,5'-dithiobis(2-nitrobenzoic acid) assay and high performance liquid chromatography tandem mass spectrometry demonstrate a direct reaction between the compounds. This study provides evidence that mesna is an efficacious, inexpensive, FDA-approved candidate antidote for SM exposure. SIGNIFICANCE STATEMENT: Despite the use of sulfur mustard (SM) as a chemical weapon for over 100 years, an ideal drug candidate for treatment after real-world exposure situations has not yet been identified. Utilizing a uniformly lethal animal model, the results of the present study demonstrate that sodium 2-mercaptoethane sulfonate is a promising candidate for repurposing as an antidote, decreasing airway obstruction and improving pulmonary gas exchange, tissue oxygen delivery, and survival following high level SM inhalation exposure, and warrants further consideration.

MESNA (2-Mercaptoethanesulfonate) Attenuates Brain, Heart, and Lung Injury Induced by Carotid Ischemia-Reperfusion in Rats.

Background: Ischemia-reperfusion (I/R) causes organ dysfunction as a result of the increased formation of various reactive oxygen metabolites, infiltration of inflammatory cells, interstitial edema, cellular dysfunction, and tissue death. Aim: The study aimed to investigate the cytoprotective effect of 2-mercaptoethanesulfonate (MESNA) against tissue damage in rats exposed to carotid ischemia-reperfusion. Materials and Methods: Twenty-four male Wistar albino rats were divided into four groups (n = 6): sham, carotid I/R, I/R + MESNA (75 mg/kg), and I/R + MESNA (150 mg/kg) groups. To induce ischemia in rats, the carotid arteries were ligated with silk sutures for 10 min; the silk suture was then opened, and 1 h reperfusion was done. MESNA (75 and 150 mg/kg) was administered intraperitoneally 30 min before ischemia-reperfusion. Tissue samples from the animals were taken for histological examination, while the serum levels of some biochemical parameters were utilized to evaluate the systemic alterations. ANOVA and Tukey's post hoc tests were applied with a significance level of 5%. Results: The ischemia-reperfusion-induced tissue damage as evidenced by increase in serum levels of alanine transaminase, aspartate aminotransferase, alkaline phosphatase, malondialdehyde, lactate dehydrogenase, and matrix metalloproteinases (MMP-1, -2, -8) was significantly (P < 0.05-0.0001) reversed after treatment with MESNA in a dose-dependent manner. Treatment with MESNA (75 and 150 mg/kg), significantly (P < 0.05-0.0001) decreased the I/R-induced increase in serum tumor necrosis factor-alpha (TNF-α) and Interleukin-1-beta (IL-1 ß). Conclusion: The results of this study suggest that MESNA has a protective effect on tissues by suppressing cellular responses to oxidants and inflammatory mediators associated with carotid ischemia-reperfusion.

High-dose continuous-infusion ifosfamide in advanced thymic epithelial Tumors: A TYME network study.

BACKGROUND: We reported the efficacy and safety results of high-dose, continuous-infusion Ifosfamide,in patients with advanced thymoma (TM) and thymic carcinoma (TC). METHODS: This was a multicentric, prospective study in patients with advanced TM or TC, who had progressed after at least one line of platinum-based chemotherapy. Previous treatment with an anti-angiogenesis or anti-PD(L)1 was allowed. Patients received Ifosfamide (1 g/m2/day) and sodium-2-mercaptoethanesulfonate (1 g/m2/day), as continuous infusion, via a portable pumps for 14 consecutive days. Treatment was administered every 4 weeks until progression or unacceptable toxicity, up to a maximum of 6 cycles. The primary endpoint was the overall response rate (ORR) assessed by RECIST1.1. Secondary endpoints included disease control rate (DCR), Progression-free survival (PFS), overall survival (OS), and safety. RESULTS: Eighteen patients were enrolled from October 2020 to January 2022. Twelve patients had a TC, 5 a TM and 1 a mixed TM/TC. Sixty-one percent of patients (11/18) had stage IVB disease according to Masaoka-Koga, and 39% (7/18) had an ECOG-PS 2. The median number of previous lines of therapy was 2 (range:1-5), and 72% (13/18) and 61% (11/18) of patients were pretreated with an anti-angiogenesis drug and an anti-PD(L)1 drug respectively. The ORR and the disease control rate (DCR) were 28 % (95 %CI: 10 %-53 %) and 67 % (95 %CI: 41 %-86 %), respectively. The median follow-up for PFS was 17.3 months (95 %CI: 4.3-NA), and median PFS was 5.4 months (95 %CI: 2.9-6.4). The median duration of response and SD was respectively 19.6 months (95 %CI: 3.5-NA) and 6.0 months (95 % CI: 3.8-6.4). In patients with TC, the ORR and DCR were 15 % (95 % CI: 2 %-45 %) and 54 % (95 % CI: 25 %-81 %), respectively. In the subgroup of 5 patients with TM, 2 PR and 3 SD were observed. Most patients had only mild (grade 1-2) AEs, the most common being nausea and vomiting (39%; 7/18) and transaminases elevation (33%; 6/18). Twenty-two percent of patients (4/18) experienced an AEs of grade 3 and required ifosfamide dose reduction. No patients had severe AEs. CONCLUSION: High-dose continuous-infusion Ifosfamide can be considered as a valuable treatment option in patients with advanced thymic epithelial tumors.

Ifosfamide-induced acute kidney injury in a patient with leiomyosarcoma: A case report.

BACKGROUND: Leiomyosarcoma (LMS) is an aggressive soft tissue sarcoma that is derived from smooth muscles. Ifosfamide is in use for advanced metastatic LMS. CASE: A-44-years old woman with a chief complaint of pain in the epigastric area, itching, coughing, nausea, and vomiting was referred to the emergency department. Her medical history was LMS. She had taken Ifosfamide and mesna in her last chemotherapy. Seventy percent of her liver and her left kidney were removed 4 years ago to prevent the progress of the disease. Because of the increase in the level of creatinine and urea in the initial laboratory report, a Shaldon catheter was inserted for the patient, and she was under emergency dialysis for 3 h. In addition, during the six-day hospitalization period, dialysis was done two times. Finally, the patient was discharged with improved clinical tests accompanied by a twice-weekly dialysis order. CONCLUSION: Ifosfamide is metabolized into chloroacetaldehyde, which can cause acute kidney injury. Recovery from acute kidney injury may not always be perfect and can lead to some degree of chronic kidney disease. Opposite to hemorrhagic cystitis, mesna is not effective in preventing ifosfamide's nephrotoxicity and N-acetylcysteine may be effective in the prevention of this nephrotoxicity.

A 'chemical help' in middle-ear surgery? A systematic review on sodium 2-mercaptoethanesulfonate.

OBJECTIVE: Sodium 2-mercaptoethanesulfonate (Mesna) has been proposed as a chemical aid in any surgical procedure, including cholesteatoma surgery. This review investigated the benefits and safety of Mesna during surgical management of cholesteatoma and adhesive otitis media. METHOD: A systematic literature review was performed to identify clinical studies evaluating topical Mesna application during ear surgery (cholesteatoma or atelectasis). A qualitative analysis based on data extracted was conducted. RESULTS: From 27 articles, 5 retrospective studies were selected for a full analysis for a total of 607 patients (aged 5 to 72 years). Three studies evaluated cholesteatoma recidivism after Mesna application during cholesteatoma surgery, one study evaluated the surgical success rate of Mesna application for the treatment of atelectatic ears and adhesive otitis media, and one study evaluated potential ototoxicity of Mesna during cholesteatoma surgery. All the studies showed overall improvement in recurrence and residual cholesteatoma disease after Mesna application during surgery. Sensorineural hearing loss was not encountered after Mesna application. CONCLUSION: Mesna application in cholesteatoma surgery could represent a valid and safe support tool during surgical treatment carried out both with microscopy and endoscopy. More studies are required to confirm these promising results.

Incidence of hemorrhagic cystitis after cyclophosphamide therapy with or without mesna: A cohort study and comprehensive literature review.

BACKGROUND: Cyclophosphamide is an alkylating agent associated with significant toxicities, most importantly hemorrhagic cystitis. Many approaches including mesna use were established to reduce this toxicity. However, data on mesna efficacy are conflicting. OBJECTIVE: To investigate the incidence of hemorrhagic cystitis in patients receiving cyclophosphamide therapy with or without mesna. METHODS: A retrospective chart review was done on all adult patients receiving cyclophosphamide therapy with or without mesna at the King Saud University Medical City. The incidence of hemorrhagic cystitis was recorded. Patients receiving mesna were compared with those not receiving mesna. Data were reported as numbers and percentages, and appropriate statistical tests of association were used. This step was followed by a comprehensive literature review using appropriate keywords in PubMed from the inception of the database until August 2019. All studies of interest were reported. RESULTS: A total of 718 patients' medical records were reviewed. The majority of the patients received mesna (n = 433, 60%). The mesna group had a greater incidence of hemorrhagic cystitis (3.5% vs. 0.4%, p < 0.004) and received a significantly larger cumulative dose (3103 ± 1696 vs. 2465 ± 1528, p < 0.001) mg of cyclophosphamide therapy. Our literature review revealed large differences in the conclusions of published trials with highly diverse study designs and populations, emphasizing on the need of large prospective trials to address this topic.Conclusion and relevance: Our study results do not support the use of mesna in preventing hemorrhagic cystitis. We found that the only influential factor in the development of hemorrhagic cystitis was the dose of cyclophosphamide therapy.

Complete remission of a case of high-grade myxofibrosarcoma with lung metastases after modified MAID regimen chemotherapy.

The role of chemotherapy in the treatment of myxofibrosarcoma is unclear. There are no randomized clinical trials evaluating the therapeutic effect of chemotherapy on myxofibrosarcoma. We report, to the best of our knowledge, the first case of myxofibrosarcoma successfully treated with mesna, pirarubicin, ifosfamide and dacarbazine (modified MAID) regimen. The patient achieved complete remission evaluated according to Response Evaluation Criteria in Solid Tumours (RECIST).

Hemorrhagic Cystitis after Haploidentical Transplantation with Post-Transplantation Cyclophosphamide: Protective Effect of MESNA Continuous Infusion.

Hemorrhagic cystitis (HC) is an important complication after haploidentical hematopoietic stem cell transplantation (haplo-HSCT) with post-transplantation cyclophosphamide (PT-CY). Sodium 2-mercaptoethanesulfonate (MESNA) can prevent bladder injury when given with PT-CY. However, the best way to deliver MESNA is not known. This study assessed the incidence of HC after haplo-HSCT with PT-CY with 2 different methods of MESNA administration. The cumulative incidence of HC was lower in patients who received MESNA as a continuous infusion compared with those who received it as an intermittent bolus (5.6% versus 27.8%; P = .01). MESNA administration as an infusion was associated with a lower risk of developing HC (hazard ratio [HR], .19; 95% confidence interval [CI], .04 to .86; P = .02) on univariate analysis. This effect remained significant after adjustment in multivariate analysis (HR, .21; 95% CI, .04 to .88; P = .03). MESNA delivered as a continuous infusion is a simple and potentially useful way to prevent HC after PT-CY.

Doxorubicin and Olaratumab Versus Doxorubicin, Ifosfamide, and Mesna for Treatment of Advanced Soft Tissue Sarcomas.

OBJECTIVE: We compared the outcomes in soft tissue sarcoma (STS) treated with olaratumab and doxorubicin (OD) versus doxorubicin, ifosfamide, and mesna (AIM) to assess whether OD could supersede AIM in STS therapy. METHODS: A single-institution, retrospective study of STS treated for advanced disease with OD or AIM in 2013 to 2017 was conducted. Demographic and clinical parameters were compared by Fisher's exact test. Kaplan-Meier and Cox analyses examined progression-free survival (PFS) and overall survival (OS). Adverse events were compared. RESULTS: Thirty patients (13 OD, 17 AIM) were included. OD was administered more commonly after first-line therapy (54% OD vs. 6% AIM, P=0.0005). The 2 groups did not differ in other parameters. Median OS [OD: 14.2 mo, 95% confidence interval (CI): 7.1-not reached; AIM 19.9 mo, 95% CI 9.5-35.5; hazard ratio: 0.99, 95% CI: 0.38-2.59, P=0.99] and PFS (OD: 2.6 mo, 95% CI: 1.3-7; AIM 6.4 mo, 95% CI: 1.5-14.5; hazard ratio: 0.57, 95% CI: 0.26-1.24, P=0.16) were not statistically different, although median values favored AIM. Grade 3 to 4 neutropenia, but not febrile neutropenia, was more frequent with OD. CONCLUSIONS: OD and AIM did not differ with respect to either OS or PFS. Although this study's size initially appeared the most likely explanation, lack of significant activity of olaratumab was subsequently reported in the phase III trial of OD. Our results suggest that future conditional oncology drug approvals should be accompanied by mandated registries to monitor outcomes of patients treated after conditional approval, but before full approval.

Impact of extended infusional mesna prophylaxis on the incidence of BK viruria and hemorrhagic cystitis following post-transplantation cyclophosphamide and CTLA4Ig-based haploidentical transplantation.

Hemorrhagic cystitis (HC) has been reported with increased frequency following post-transplantation cyclophosphamide (PTCy)-based haploidentical hematopoietic cell transplantation (HCT) along with a strong association with BK viruria. We prospectively evaluated the incidence of BK viruria and HC in 115 patients (median age 20 years, 2-65) undergoing PTCy-based haploidentical HCT with (n = 71) or without (n = 44) CTLA4Ig. HC prophylaxis consisted of a continuous infusion of mesna 30 min prior and 48 h post-PTCy. The overall incidence of BK viruria was 65.7%. None with BK viruria < 104 copies/ml developed clinical symptoms (n = 65). The incidence of BK viruria ≥ 104 copies/ml was 7.1% (n = 8) and 75% developed HC. The incidence of HC was 5.4% at a median of 30 days. Both BK viruria ≥ 104 copies/ml and HC were strongly associated with acute GVHD (p < 0.001). A higher NRM was observed in those with BK viruria ≥ 104 copies/ml, related to GVHD and its complications (41.7% vs 12.6%, p = 0.04). The incidences of acute GVHD, vis-à-vis, overall BK viruria, BK viruria ≥ 104 copies/ml, and HC, tended to be lower in patients receiving CTLA4Ig. Thus, extended infusional mesna, coupled with significant reduction in alloreactivity along with possible preservation of antiviral immunity associated with the use of CTLA4Ig, was probably responsible for a much lower incidence of BK viruria and resultant HC than reported previously following PTCy-based haploidentical HCT.

Neoadjuvant chemotherapy for primary sarcoma of the breast: a case report.

BACKGROUND: Primary sarcoma of the breast is rare. Surgery has been the only curative treatment available. Recently, neoadjuvant chemotherapy including anthracycline/ifosfamide has been reported effective for patients with high-risk sarcomas in a prospective trial. CASE PRESENTATION: A 52-year-old Japanese woman presented with a mass in her left breast. The 10 cm tumor was fixed to her chest wall on examination. A skin biopsy was performed which showed leiomyosarcoma. Neoadjuvant chemotherapy was given and the tumor became mobile. A mastectomy and axillary dissection were performed with surgically negative margins. After neoadjuvant chemotherapy, the amount of necrosis was profoundly influenced by chemotherapy, and the histological effect of neoadjuvant chemotherapy was assessed in reference to pre-neoadjuvant chemotherapy magnetic resonance imaging. CONCLUSION: In contrast to many other cancers, the evaluation of various treatments and of the histological effect of neoadjuvant chemotherapy for sarcoma has been difficult due to the rarity of these tumors. We report the case of a patient with a breast sarcoma, treated with neoadjuvant chemotherapy and discuss the appropriate pathological evaluation and therapeutic management.

Primary angiosarcoma of thyroid.

Mesenchymal origin of primary thyroid angiosarcomas (TAS) is extremely rare and comprises less than 1% of primary thyroid cancer worldwide. While TAS are most commonly occurring in the Alpine region, there are multiple reported cases of TAS in non-Alpine regions. Diagnosis of TAS is commonly made after thyroidectomy as cytologic diagnosis can be challenging due to paucity of cells, presence of necrosis and unawareness of the disease due to rarity. We report a case of primary TAS diagnosed by cytology in a 56-year-old man who presented with a sudden onset of left neck pain, swelling and haemoptysis. He was later noted to have suspicious nodules on both lobes of thyroid on ultrasound. Fine needle aspiration of thyroid nodules showed malignant epithelioid cells. The diagnosis of TAS was made based on positive endothelial markers such as thrombomodulin and CD31, with many pertinent negatives, including negative cytokeratins,thyroid transcription factor (TTF1), thyroglobulin, calcitonin and carcinoembryonic antigen (CEA).

MAID chemotherapy regimen as a treatment strategy for metastatic malignant ameloblastoma: A case report.

RATIONALE: Ameloblastoma is generally characterized as a benign tumor originating in odontogenic epithelium. However, few cases of metastatic malignant ameloblastoma have also been reported. Due to the low incidence of malignant ameloblastoma, there is no established treatment regimen. To explore effective treatment for malignant ameloblastoma, we reported this case study. PATIENTS CONCERNS: This report described a case of a 28-year-old malignant ameloblastoma female patient with multiple metastasis (brain and lung). DIAGNOSES: The patient presented ameloblastoma of the left mandible in 2012. Three years later, local recurrence and brain metastasis was observed during a follow-up examination. Five years later, malignant ameloblastoma was detected by imaging and immunohistochemistry in the bilateral multiple pulmonary nodules and mediastinal lymph nodes. INTERVENTIONS: The patient was initially treated with tumor resection. Three years later after local recurrence and brain metastasis, she was accepted the extensive mandibulectomy supplemented with brain stereotactic body radiotherapy (SBRT). When diagnosed with pulmonary metastasis, the patient received combined chemotherapy regimen of MAID (mesna, adriamycin, ifosfamide and dacarbazine) for 6 cycles. OUTCOMES: The efficacy evaluation was partial remission (PR) after the 6 cycles of MAID. The last patient follow-up was July 24th 2018, and no evidence of progression was observed. The progression-free survival (PFS) of the patient was more than 9 months. LESSONS: Surgical resection is the optimal treatment for locally recurrent ameloblastoma. SBRT may be an effective treatment for unresectable oligometastasis of malignant ameloblastoma. Finally, combined chemotherapy of MAID showed encouraging effects in the management of metastatic malignant ameloblastoma.

Chemically Assisted Dissection With Sodium 2-Mercaptoethanesulfonate (MESNA) in the Surgical Management of Pediatric Cholesteatoma.

OBJECTIVE: To evaluate the effectiveness of the chemically assisted dissection with sodium 2-mercaptoethanesulfonate (MESNA), in the reduction of residual and recurrent cholesteatoma after mastoidectomy in children with chronic cholesteatomatous otitis media (CCOM). STUDY DESIGN: Retrospective case-control study. SETTING: Tertiary referral center. POPULATION: One hundred forty mastoidectomies performed in patients under 18 years of age for the treatment of CCOM. INTERVENTIONS: Chemically assisted dissection (CAD) with MESNA compared with surgical dissection without MESNA. MAIN OUTCOME MEASURES: Recidivism of cholesteatoma (recurrence and residual disease), variations in the average of bone conduction threshold after treatment, and complications. RESULTS: Recidivism of cholesteatoma was significantly lower when CAD with MESNA was used (p < 0.0001). No difference was found in the mean variation of the average of bone conduction thresholds between the groups, confirming its safety profile regarding auditory function. Meatoplasty stenosis after surgery was more prevalent within CAD with MESNA group (p: 0.049). CONCLUSION: Recurrent and residual cholesteatoma remains a problem, especially in children and despite surgical techniques such as canal wall down mastoidectomy and endoscopic ear surgery. CAD with MESNA can be safe and effective to reduce recurrence rates. Multicenter and prospective studies with larger number of patients are needed to validate these findings. The higher rate of meatoplasty stenosis after CAD with MESNA merits additional clinical research to confirm these findings, as well as in vitro studies evaluating the effect of the drug on the activity of fibroblasts and other growth factors that may be involved.

Cyclophosphamide-induced hemorrhagic cystitis in young patients with solid tumors: A single institution study.

AIM: Although hemorrhagic cystitis (HC) is a significant complication in young patients who undergo chemotherapy with cyclophosphamide (CPA), risk factors and supportive care to prevent HC are unclear. This study attempted to identify optimal supportive care to prevent CPA-induced HC. METHODS: Patients (< 30-year-old) with malignant solid tumors who had been treated with CPA-containing chemotherapy in inpatient treatment were eligible. Vigorous hydration to increase urine output and intravenous 2-mercaptethane sulfonate (mesna) were used for prophylaxis of CPA-induced HC. We retrospectively analyzed 81 patients who had been treated with CPA-containing chemotherapy over (collectively) 486 cycles, and examined relationships between HC and various factors, especially CPA dosage, use of mesna, and fluid infusion volume/rate. RESULTS: HC occurred in four patients (4.9%) and five cycles (1%). When stratifying by doses and methods of administration of CPA, HC occurred in 3/323 low- and intermediate-dose (< 1500 mg/m2 /day) cycles and mesna was used in all three cycles with HC. Patients who were given mesna had a lower flow rate than those given hydration alone in the low- and intermediate-dose CPA (126 ± 25 vs 106 ± 16 mL/m2 /h; P < 0.01). All patients who received high-dose CPA (≥1500 mg/m2 /day) were also given mesna and vigorous hydration (115 ± 16 mL/m2 /h). CONCLUSIONS: Our supportive care measures may be effective in preventing CPA-induced HC. Patients who receive CPA doses < 1500 mg/m2 /day should get ≥125 mL/m2 /h of infused fluid, regardless of mesna usage; those who receive of CPA ≥1500 mg/m2 /day should also receive mesna and vigorous hydration.

Efficacy of mesna, doxorubicin, ifosfamide, and dacarbazine (MAID) in patients with advanced pulmonary pleomorphic carcinoma.

OBJECTIVES: Pulmonary pleomorphic carcinoma (PC) is a rare type of lung tumor with a dismal prognosis. There is no consensus on a chemotherapy regimen for PC, and conventional platinum-based chemotherapy has been associated with disappointing response rates and PFS. In searches for a new regimen, the sarcomatoid (spindle or giant cell) component has been assumed to be susceptible to chemotherapy used for soft tissue sarcoma. MATERIALS AND METHODS: The medical records of 17 patients who received mesna, doxorubicin, ifosfamide, and dacarbazine (MAID) for advanced PC between January 2010 and February 2017 were retrospectively analyzed for clinicopathological features and outcomes. RESULTS AND CONCLUSION: The median age was 59 years. Sixteen patients were male, and only one patient had never smoked. Six patients achieved partial response to MAID, leading to an objective response rate of 35%. The median PFS was 2.8 months, and the median OS was 8.7 months. Hematologic toxicity-related adverse events were the most frequent, which comprised grade 3-4 anemia in 35% of patients, neutropenia in 47%, thrombocytopenia in 24%, and febrile neutropenia in 29%. No febrile neutropenia was reported in patients who received 5-day granulocyte-colony stimulating factor (G-CSF) prophylaxis. Most adverse events resolved without complications, except for one death due to sepsis. MAID is an effective, and possibly important, regimen for PC. MAID could be more safely used in clinical practice with appropriate dose modifications and G-CSF primary prophylaxis according to patients' status.

Neutrophils contribute to the pathogenesis of hemorrhagic cystitis induced by ifosfamide.

Ifosfamide (IFO) is an antineoplastic drug that is commonly used to treat gynecological and breast cancers. Hemorrhagic cystitis (HC) is a common side effect associated with IFO injection, which courses with neutrophil accumulation and affects 6-50% of patients depending on dose intensity. Here, we investigated the role of neutrophils in this inflammatory process. Female Swiss mice (n = 8/group) were injected with saline, IFO (400 mg/kg, i.p.), fucoidan (a P- and L-selectins inhibitor, 100 mg/kg, i.v.) or IFO + fucoidan (1-100 mg/kg) alone or combined with mesna (80 mg/kg i.p.). Another group of mice received anti-Ly6G antibody (500 µg/mouse, once daily for 2 days) for neutrophil depletion before IFO injection. In another experimental setting, animals received granulocyte colony-stimulating factor (G-CSF, 400 µg/kg), IFO (200 mg/kg), G-CSF (25-400 µg/kg, for 5 days) + IFO (200 mg/kg, i.p.) or fucoidan + G-CSF + IFO. Bladder injury was evaluated 12 h after IFO injection. IFO 400 mg/kg significantly increased visceral hyperalgesia, bladder edema, hemorrhage, vascular permeability, MPO, IL-1ß and IL-6 tissue levels, and COX-2 immunostaining and expression versus the saline group (P < 0.05). Conversely, fucoidan (100 mg/kg) significantly attenuated these parameters compared to IFO-injected mice (P < 0.05). Additionally, fucoidan potentiated mesna protective effect when compared with IFO + mesna group (P < 0.05). Accordingly, neutrophil depletion with anti-Ly6G reduced inflammatory parameters and bladder injury compared to IFO (P < 0.05). In contrast, G-CSF enhanced IFO (200 mg/kg)-induced HC, which was significantly attenuated by treatment with fucoidan (P < 0.05). Therefore, neutrophils contribute to the pathogenesis of HC.

Changes in biofilm in chronic cholesteatomatous otitis media in children following the application of sodium 2-mercaptoethanesulfonate (MESNA).

BACKGROUND: Pediatric cholesteatoma is a clinically challenging disease entity. Its biological behavior in the pediatric population differs from its behavior in adult population in terms of aggressiveness and recurrence. Several studies have shown the presence of biofilms associated with cholesteatoma that hinder the management and eradication of the infection. This led is to study the use of non-antimicrobial treatments impacting on the structure or composition of biofilms. OBJECTIVE: To evaluate the changes that occur in the biofilm of cholesteatoma in pediatric patients after the application of sodium 2-mercaptoethanesulfonate (MESNA). METHODS: A pilot study of 10 pediatric patients, with a median age of 10 years and a diagnosis of cholesteatomatous chronic otitis media, who underwent surgery for primary or revision mastoidectomy in the Otorhinolaryngology Service of the Hospital Infantil de México Federico Gómez between January 2016 and May 2017. During the surgery, basal samples of cholesteatoma and tissue were taken after topical application of 4% MESNA for 10 min. The samples were then processed for confocal laser microscopy. RESULTS: In all samples structures compatible with bacterial biofilms were identified. The most relevant finding was the changes in the structure of the biofilm after the application of MESNA, such as disintegration and separation of the underlying tissue. CONCLUSIONS: This is the first study that showing changes associated with cholesteatoma in the structure of the bacterial biofilm after the application of MESNA. The observed disintegration of cholesteatoma biofilm ultrastructure could aid in the management of the chronic infection associated with cholesteatoma.