Impact of Natural Organic Matter Competition on the Adsorptive Removal of Acetochlor and Metolachlor from Low-Specific UV Absorbance Surface Waters

Although activated carbon adsorption is a very promising process for the removal of organic compounds from surface waters, the removal performance for nonionic pesticides could be adversely affected by co-occurring natural organic matter. Natural organic matter can compete with pesticides during the adsorption process, and the size of natural organic matter affects the removal of pesticides, as low-molecular-weight organics directly compete for adsorbent sites with pesticides. This study aims to investigate the competitive impact of low-molecular-weight organics on the adsorptive removal of acetochlor and metolachlor by four commercial powdered activated carbons. The adsorption features of selected powdered activated carbons were evaluated in surface water samples collected from the influent stream of the filtration process having 2.75 mg/L organic matter and 0.87 L/mg-m specific UV absorbance. The adsorption kinetics and capacities were examined by employing pseudo-first-order, pseudo-second-order, and intraparticle diffusion kinetic models and modified Freundlich and Langmuir isotherm models to the experimental data. The competitive removal of acetochlor and metolachlor in the presence of natural organic matter was evaluated for varied powdered activated carbon dosages on the basis of UV and specific UV absorbance values of adsorbed organic matter. The adsorption data were well represented by the modified Freundlich isotherm, as well as pseudo-second-order kinetics. The maximum organic matter adsorption capacities of the modified Freundlich isotherm were observed to be 120.6 and 127.2 mg/g by Norit SX Ultra and 99.5 and 100.6 mg/g by AC Puriss for acetochlor- and metolachlor-containing water samples, respectively. Among the four powdered activated carbons, Norit SX Ultra and AC Puriss provided the highest natural organic matter removal performances with 76 and 72% and 71 and 65% for acetochlor- and metolachlor-containing samples, respectively. Similarly, Norit SX Ultra and AC Puriss were very effective for adsorbing aromatic organics with higher than 80% specific UV absorbance removal efficiency. Metolachlor was almost completely removed by higher than 98% by Norit SX Ultra, Norit SX F Cat, and AC Puriss, even at low adsorbent dosages. However, an adsorbent dose of 100 mg/L and above should be added for all powdered activated carbons, except for Norit SX F Cat, for achieving an acetochlor removal performance of higher than 98%. The competition between low-molecular-weight organics (low-specific UV absorbance) and acetochlor and metolachlor was more apparent at low adsorbent dosages (10-75 mg/L)

COMPARISON OF INTRATHECAL PLAIN AND HYPERBARIC BUPIVACAINE WITH MORPHINE FOR POSTOPERATIVE ANALGESIA FOLLOWING CESAREAN SECTION

Amaç: Bu gözlemsel çalışmada, primer amacımız intratekal izobarik ve hiperbarik bupivakain ile morfin birlikteliğinin postoperatif analjezik tu¨ketimi u¨zerine etkilerini karşılaştırmaktır. Gereç ve Yöntem: Etik komite onayı ve yazılı onam sonrası, elektif sezeryan planlanan 40 hasta çalışmaya dahil edildi. Hastalara 12.5 mg (2.5 ml) izobarik (İB) veya hiperbarik bupivakain (HB), 150 μg (0.75 ml) morfin ile birlikte spinal anestezi amacıyla uygulandı. Postoperatif analjezi, tramadol ile hazırlanan hasta kontrollu¨ analjezi (HKA) ile sağlandı. Postoperatif dönemde hastaların 24 saatlik tramadol tu¨ketimleri, blok özellikleri, ilk analjezik ihtiyaç su¨releri, hemodinamik verileri, intraoperatif analjezik ihtiyaçları, yan etkileri (bulantı, kusma, titreme, kaşıntı) ve memnuniyetleri karşılaştırıldı. Bulgular: İB grubunda 24 saatlik tramadol tu¨ketimi HB grubuna göre belirgin du¨şu¨k bulundu (72.8±22.2mg, 127±43.2; p<0.001). Blok başlama su¨releri, sefale yayılım, duyusal ve motor blok sonlanma su¨releri açısından iki grup arasında fark bulunmadı. İlk analjezik ihtiyaç su¨resi, İB grubunda HB grubuna göre belirgin şekilde daha uzundu (456.6±209 dk, 265 ±138.2 dk; p=0.002). İntraoperatif hipotansiyon ile, HB grubunda İB grubuna göre daha sık karşılaşıldı (65% vs 20%; p=0.01). İntraoperatif analjezik ihtiyacı, perioperatif yan etkiler ve hasta memnuniyetleri benzer bulundu. Sonuç: İzobarik bupivakain ve morfinin birlikte kullanımı, 24 saatlik analjezik tu¨ketimini belirgin şekilde du¨şu¨ru¨rken ilk analjezik kullanım su¨resini de uzatmıştır. İzobarik bupivakain ile morfin kombinasyonunun sezeryan olgularında spinal anestezi için kullanımı bu avantajları sebebiyle önerilmektedir

Safety and efficacy of eculizumab in anti-acetylcholine receptor antibody-positive refractory generalised myasthenia gravis (REGAIN): a phase 3, randomised, double-blind, placebo-controlled, multicentre study

Background Complement is likely to have a role in refractory generalised myasthenia gravis, but no approved therapies specifically target this system. Results from a phase 2 study suggested that eculizumab, a terminal complement inhibitor, produced clinically meaningful improvements in patients with anti-acetylcholine receptor antibody-positive refractory generalised myasthenia gravis. We further assessed the efficacy and safety of eculizumab in this patient population in a phase 3 trial. Methods We did a phase 3, randomised, double-blind, placebo-controlled, multicentre study (REGAIN) in 76 hospitals and specialised clinics in 17 countries across North America, Latin America, Europe, and Asia. Eligible patients were aged at least 18 years, with a Myasthenia Gravis-Activities of Daily Living (MG-ADL) score of 6 or more, Myasthenia Gravis Foundation of America (MGFA) class II\ue2\u80\u93IV disease, vaccination against Neisseria meningitides, and previous treatment with at least two immunosuppressive therapies or one immunosuppressive therapy and chronic intravenous immunoglobulin or plasma exchange for 12 months without symptom control. Patients with a history of thymoma or thymic neoplasms, thymectomy within 12 months before screening, or use of intravenous immunoglobulin or plasma exchange within 4 weeks before randomisation, or rituximab within 6 months before screening, were excluded. We randomly assigned participants (1:1) to either intravenous eculizumab or intravenous matched placebo for 26 weeks. Dosing for eculizumab was 900 mg on day 1 and at weeks 1, 2, and 3; 1200 mg at week 4; and 1200 mg given every second week thereafter as maintenance dosing. Randomisation was done centrally with an interactive voice or web-response system with patients stratified to one of four groups based on MGFA disease classification. Where possible, patients were maintained on existing myasthenia gravis therapies and rescue medication was allowed at the study physician's discretion. Patients, investigators, staff, and outcome assessors were masked to treatment assignment. The primary efficacy endpoint was the change from baseline to week 26 in MG-ADL total score measured by worst-rank ANCOVA. The efficacy population set was defined as all patients randomly assigned to treatment groups who received at least one dose of study drug, had a valid baseline MG-ADL assessment, and at least one post-baseline MG-ADL assessment. The safety analyses included all randomly assigned patients who received eculizumab or placebo. This trial is registered with ClinicalTrials.gov, number NCT01997229. Findings Between April 30, 2014, and Feb 19, 2016, we randomly assigned and treated 125 patients, 62 with eculizumab and 63 with placebo. The primary analysis showed no significant difference between eculizumab and placebo (least-squares mean rank 56\uc2\ub76 [SEM 4\uc2\ub75] vs 68\uc2\ub73 [4\uc2\ub75]; rank-based treatment difference \ue2\u88\u9211\uc2\ub77, 95% CI \ue2\u88\u9224\uc2\ub73 to 0\uc2\ub796; p=0\uc2\ub70698). No deaths or cases of meningococcal infection occurred during the study. The most common adverse events in both groups were headache and upper respiratory tract infection (ten [16%] for both events in the eculizumab group and 12 [19%] for both in the placebo group). Myasthenia gravis exacerbations were reported by six (10%) patients in the eculizumab group and 15 (24%) in the placebo group. Six (10%) patients in the eculizumab group and 12 (19%) in the placebo group required rescue therapy. Interpretation The change in the MG-ADL score was not statistically significant between eculizumab and placebo, as measured by the worst-rank analysis. Eculizumab was well tolerated. The use of a worst-rank analytical approach proved to be an important limitation of this study since the secondary and sensitivity analyses results were inconsistent with the primary endpoint result; further research into the role of complement is needed. Funding Alexion Pharmaceuticals