Occurrence, Geochemistry and Speciation of Elevated Arsenic Concentrations in a Fractured Bedrock Aquifer System.

The presence of elevated arsenic concentrations (≥ 10 µg L-1) in groundwaters has been widely reported in areas of South-East Asia with recent studies showing its detection in fractured bedrock aquifers is occurring mainly in regions of north-eastern USA. However, data within Europe remain limited; therefore, the objective of this work was to understand the geochemical mobilisation mechanism of arsenic in this geologic setting using a study site in Ireland as a case study. Physicochemical (pH, Eh, d-O2), trace metals, major ion and arsenic speciation samples were collected and analysed using a variety of field and laboratory-based techniques and evaluated using statistical analysis. Groundwaters containing elevated dissolved arsenic concentrations (up to 73.95 µg L-1) were characterised as oxic-alkali groundwaters with the co-occurrence of other oxyanions (including Mo, Se, Sb and U), low dissolved concentrations of Fe and Mn, and low Na/Ca ratios indicated that arsenic was mobilised through alkali desorption of Fe oxyhydroxides. Arsenic speciation using a solid-phase extraction methodology (n = 20) showed that the dominant species of arsenic was arsenate, with pH being a major controlling factor. The expected source of arsenic is sulphide minerals within fractures of the bedrock aquifer with transportation of arsenic and other oxyanion forming elements facilitated by secondary Fe mineral phases. However, the presence of methylarsenical compounds detected in groundwaters illustrates that microbially mediated mobilisation processes may also be (co)-occurring. This study gives insight into the geochemistry of arsenic mobilisation that can be used to further guide research needs in this area for the protection of groundwater resources.

A single topical agent is clinically equivalent to the combination of topical and oral antibiotic treatment for otitis externa.

OBJECTIVE: To demonstrate clinical equivalence (statistical noninferiority) of topical ciprofloxacin and hydrocortisone (CHC, Cipro HC) and topical neomycin/polymyxin b/hydrocortisone (NPH, Cortisporin) with systemic amoxicillin (AMX, Amoxil), for treatment of acute otitis externa (AOE). DESIGN: Randomized, active-control, observer-blind, multicenter trial. PATIENTS: Altogether, 206 patients were enrolled (CHC, 106; NPH + AMX, 100). Patients were > or =1 year of age, had AOE >2 days with at least mild symptoms, and gave informed consent. All were evaluable for safety, and 151 were evaluable for efficacy. INTERVENTIONS: Ciprofloxacin and hydrocortisone 3 drops twice daily for 7 days (adults and children) or NPH 4 drops (adults) or 2 drops (children) with AMX 250 mg (adults and children) 3 times daily for 10 days, as directed in approved product labeling. MAIN OUTCOME MEASURES: The primary efficacy variable was response to therapy 7 days after treatment ended (test of cure). Secondary variables included time to end of pain, symptom scores (otalgia and tenderness) and microbiological eradication. Noninferiority was declared if the lower confidence limit around the measurement difference was above -10 (nearer zero). RESULTS: Response to therapy was higher for CHC (95.71% vs 89.83%) but was statistically noninferior (lower confidence limit, -4.98) to NPH + AMX. Median time to end of pain was 6 days for both groups. Noninferiority was declared for symptom scores at all measurement periods and for microbiological eradication. No serious adverse events related to treatment were reported. CONCLUSIONS: Ciprofloxacin and hydrocortisone is clinically equivalent to NPH + AMX for the treatment of AOE in adults and children. However, low systemic exposure, absence of ototoxicity, and less frequent dosing clearly favor Cipro HC.

Randomized, placebo-controlled evaluation of Cerumenex and Murine earwax removal products.

OBJECTIVE: To evaluate the efficacy of 2 ceruminolytic products, Cerumenex Eardrops (Purdue Frederick Company, Norwalk, Conn) and Murine Ear Drops (Abbott Laboratories, Abbott Park, Ill), in subjects with partial or complete occlusion of the ear canal due to cerumen. DESIGN: Randomized, subject- and observer-blind, placebo-controlled, clinical trial. SETTING: Corporate research clinic. PARTICIPANTS: From among 230 volunteers screened, 74 subjects (age, 22-66 [mean, 45] years) were enrolled in the study. Participants had baseline occlusion levels of mild (n = 10), moderate (n = 26), or complete (n = 38) impairment of tympanic membrane visualization. INTERVENTIONS: Subjects were randomly assigned to 1 of 3 treatments: Cerumenex (10% triethanolamine polypeptide oleate-condensate), Murine (6.5% carbamide peroxide), and a placebo, BSS Sterile Irrigating Solution (Alcon Laboratories Inc, Ft Worth, Tex). The test medication was instilled into 1 occluded ear for up to two 15-minute applications. Following the treatment, the subject's ear was irrigated with 50 mL of lukewarm water delivered at low pressure via a WaterPik irrigator equipped with a Grossan irrigator tip. Main Outcome Measure The degree of occlusion, measured against a previously established 4-point scale, was assessed and recorded at baseline and after each instillation and irrigation procedure. RESULTS: Neither Cerumenex nor Murine was superior to saline placebo. By the end of treatment, 29.2%, 15.4%, and 41.7% of subjects treated with Cerumenex, Murine, and placebo, respectively, experienced resolution of cerumen occlusion. These values were not statistically significantly different from one another. CONCLUSION: The currently marketed ceruminolytic products, Cerumenex and Murine, are no more effective than a saline placebo in removing earwax.

Efficacy and safety of topical ciprofloxacin/dexamethasone versus neomycin/polymyxin B/hydrocortisone for otitis externa.

OBJECTIVES: To compare the efficacy and safety of ciprofloxacin 0.3%/dexamethasone 0.1% (CIP/DEX) otic suspension with that of neomycin 0.35%/polymyxin B 10,000 IU/mL/hydrocortisone 1.0% (N/P/H) otic suspension in patients with acute otitis externa (AOE). STUDY DESIGN: Randomized, observer-masked, parallel-group, multicenter study. Patients were randomized to 7 days treatment with either CIP/DEX 3-4 drops twice daily or N/P/H 3-4 drops three times daily. POPULATION: Patients of either sex and older than 1 year, with a clinical diagnosis of mild, moderate, or severe AOE and intact tympanic membranes were recruited to participate. OUTCOMES MEASURED: Signs and symptoms of AOE, including ear inflammation, tenderness, edema and discharge (assessed on Days 3, 8 [End-of-Therapy] and 18 [Test-of-Cure]); microbiologic eradication (presumed or documented); and frequency of adverse events. RESULTS: Patients enrolled numbered 468. In culture-positive patients who met the inclusion criteria (N = 396), clinical cure rates at Day 18 were significantly higher with CIP/DEX than with N/P/H (90.9% vs. 83.9%; p = 0.0375), as were microbiologic eradication rates (94.7% vs. 86.0%; p = 0.0057). In addition, the clinical response was significantly better with CIP/DEX than with N/P/H at Days 3 and 18 (p = 0.0279 and p = 0.0321, respectively), as was the reduction in ear inflammation at Day 18 (p = 0.0268). Both preparations were well tolerated in pediatric and adult patients. CONCLUSIONS: 7 days treatment with CIP/DEX otic suspension administered twice daily is clinically and microbiologically superior to N/P/H otic suspension administered 3 times daily in the treatment of mild to severe AOE, and is equally well tolerated.

Topical ciprofloxacin/dexamethasone otic suspension is superior to ofloxacin otic solution in the treatment of granulation tissue in children with acute otitis media with otorrhea through tympanostomy tubes.

OBJECTIVE: Comparison of topical ciprofloxacin/dexamethasone otic suspension (CIP/DEX) to ofloxacin otic solution (OFL) for treatment of granulation tissue in children with AOMT. STUDY DESIGN: 599 children aged >/=6 months to 12 years with AOMT of up to 3 weeks' duration were enrolled. Patients received either CIP/DEX 4 drops twice daily for 7 days or OFL 5 drops twice daily for 10 days. Granulation tissue severity was graded at clinic visits on days 1, 3, 11, and 18. RESULTS: Granulation tissue was present in 90 of 599 AOMT patients (15.0%) at baseline. CIP/DEX treatment was superior to OFL for reduction of granulation tissue at the day 11 visit (81.3% compared with 56.1%, P = 0.0067) and the day 18 visit (91.7% compared with 73.2%, P = 0.0223). Both topical otic preparations are safe and well tolerated in pediatric patients. CONCLUSION: CIP/DEX was superior to OFL in the treatment of granulation tissue in children with AOMT.

Topical ciprofloxacin/dexamethasone otic suspension is superior to ofloxacin otic solution in the treatment of children with acute otitis media with otorrhea through tympanostomy tubes.

OBJECTIVE: To determine the efficacy and safety of topical ciprofloxacin/dexamethasone otic suspension compared with ofloxacin otic solution in the treatment of acute otitis media with otorrhea through tympanostomy tubes (AOMT) in pediatric patients. METHODS: This multicenter, prospective, randomized, observer-masked, parallel-group study was conducted at 39 sites in 599 children aged >or=6 months to 12 years with an AOMT episode of

Topical ciprofloxacin/dexamethasone is superior to ciprofloxacin alone in pediatric patients with acute otitis media and otorrhea through tympanostomy tubes.

OBJECTIVE: To determine whether topical administration of a corticosteroid improves resolution of acute tympanostomy tube otorrhea when combined with topical antibiotic drops. STUDY DESIGN: Randomized, patient-masked, parallel-group, multicenter trial of topical otic ciprofloxacin/dexamethasone versus topical ciprofloxacin alone in 201 children aged 6 months to 12 years with acute otitis media with tympanostomy tubes (AOMT) of less than or equal to 3 weeks' duration and visible otorrhea. METHODS: Eligible patients were randomized to receive three drops of either ciprofloxacin 0.3%/dexamethasone 0.1% or ciprofloxacin 0.3% into the affected ear or ears twice daily for 7 days. Clinical signs and symptoms of AOMT were evaluated on days 1 (baseline), 3, 8 (end-of-therapy), and 14 (test-of-cure), and twice-daily assessments of otorrhea were recorded in patient diaries. RESULTS: The mean time to cessation of otorrhea in the microbiologically culture-positive patient population (n = 167) was significantly shorter with topical ciprofloxacin/dexamethasone than with ciprofloxacin alone (4.22 vs. 5.31 days; P =.004). This resulted in significantly better clinical responses on days 3 and 8 (P <.0001 and P =.0499, respectively). However, there were no significant differences between the two treatment groups in either the clinical response or the microbial eradication rate by day 14. CONCLUSIONS: Topical otic treatment with ciprofloxacin/dexamethasone is superior to treatment with ciprofloxacin alone and results in a faster clinical resolution in children with AOMT. The contribution of the corticosteroid in achieving a 20% reduction (1.1 day) in time to cessation of otorrhea is clinically meaningful and represents an important advance over single-agent antibiotic therapy.