Sodium Thiosulfate Improves Hypertension in Rats with Adenine-Induced Chronic Kidney Disease

Hypertension is highly prevalent in chronic kidney disease (CKD). Hydrogen sulfide (H2S) is an endogenously produced gasotransmitter with vasodilator properties. We, hence, investigated whether oral administration of sodium thiosulfate (STS), a clinically applicable H2S-based therapy, can exert a protective effect against hypertension in an adenine-induced CKD rat model. Eight-week-old male Sprague–Dawley rats were fed with 0.5% adenine chow for 3 weeks to induce CKD. After 1 week, the rats were divided into two groups: one without and one with STS (2 g/kg body weight/day) in drinking water for 2 weeks. Treatment with STS lowered systolic and diastolic blood pressure by 7 and 9 mm Hg, respectively. Renal H2S-generating enzyme expression was inhibited by CKD, while STS therapy increased plasma levels of H2S and thiosulfate. Additionally, restoration of nitric oxide bioavailability and rebalance of the renin–angiotensin system may contribute to the protective effects of STS. Our data suggest that the oral administration of STS improves hypertension in an adenine-induced CKD model, which brings us closer to the clinical translation of H2S-targeting therapy in CKD-induced hypertension.

Success of small-dose fractionated sodium thiosulfate in the treatment of calciphylaxis in a peritoneal dialysis patient

Background Calciphylaxis, or calcific uremic arteriolopathy (CUA), is a rare, fatal disorder of microvascular calcification and thrombosis that typically affects patients with end-stage renal disease (ESRD) receiving long-term dialysis. Fewer reports describe calciphylaxis in peritoneal dialysis patients than hemodialysis patients as per a literature review. To date, there are no clear guidelines for CUA diagnosis and treatment. While sodium thiosulfate (STS) has been increasingly used for treatment in recent years, there have also been reports of severe side effects. There is no uniform standard for its usage and dosage, especially for peritoneal dialysis patients. Case presentation We present a case of a 40-year-old Chinese male patient with ESRD on peritoneal dialysis who developed calciphylaxis with severe painful cutaneous ulcers on the fingers and toes that were managed successfully for 6 months with comprehensive treatment composed mainly of small-dose fractionated sodium thiosulfate. Conclusions Our experience suggests that the treatment of calciphylaxis requires timely and multi-angle intervention. Treatment with small-dose fractionated sodium thiosulfate has proven effective and tolerated in this patient.

Sulfidation of Zero-valent Iron Nanoparticles for Environmental Remediation

<p>The ability of nano-sized zero-valent iron (nZVI) to remove environmental contaminants, from heavy metals to polyhalogenated hydrocarbons, has been well established. However, the reactivity of nZVI towards contaminants is hampered due to competing for side reactions with oxygen and water. Sulfidemodified nZVI (S-nZVI) has become a viable option as S-nZVI has been shown to reduce organic compounds such as trichloroethylene faster than nZVI while also maintaining an increased resistance to oxidation by water. The Fulton group has established that nZVI supported on a naturally occurring microsilicate (Microsilica600, or “misi”), from a Rotorua geothermal deposit, is capable of removing nitrates from water. This material, or nZVI@misi, minimises the potential bioaccumulation path that nZVI has, and is easier to handle than unsupported nZVI. This research investigated the effect of sulfidation of nZVI@misi (or S-nZVI@misi) on the reactivity towards the degradation of a variety of different potential contaminants. S-nZVI@misi was synthesised using sodium thiosulfate for sulfidation. Increasing the concentration of the reagent and sulfidation time from 3 hours to 24 hours resulted in high percentages of sulfur-to-iron (S/Fe) for each material. This increase in S/Fe had a significant impact on the removal of cadmium and chromium as with higher the percentage of S/Fe, the faster the removal of these species occurred. Compared to pristine nZVI@misi, S-nZVI@misi was significantly faster at removing both cadmium and chromium. However, sulfidation of nZVI@misi proved to reduce the rate of 4-nitrophenol reduction and prevent nitrate reduction from occurring. Experimental analysis also showed that cadmium removal was faster with S-nZVI supported by FeOOH-coated microsilica, compared to material supported by un-coated microsilica. Therefore, we have synthesised supported S-nZVI that quickly removes cadmium and chromium from solution compared to standard supported nZVI.</p>

Sulfidation of Zero-valent Iron Nanoparticles for Environmental Remediation

<p>The ability of nano-sized zero-valent iron (nZVI) to remove environmental contaminants, from heavy metals to polyhalogenated hydrocarbons, has been well established. However, the reactivity of nZVI towards contaminants is hampered due to competing for side reactions with oxygen and water. Sulfidemodified nZVI (S-nZVI) has become a viable option as S-nZVI has been shown to reduce organic compounds such as trichloroethylene faster than nZVI while also maintaining an increased resistance to oxidation by water. The Fulton group has established that nZVI supported on a naturally occurring microsilicate (Microsilica600, or “misi”), from a Rotorua geothermal deposit, is capable of removing nitrates from water. This material, or nZVI@misi, minimises the potential bioaccumulation path that nZVI has, and is easier to handle than unsupported nZVI. This research investigated the effect of sulfidation of nZVI@misi (or S-nZVI@misi) on the reactivity towards the degradation of a variety of different potential contaminants. S-nZVI@misi was synthesised using sodium thiosulfate for sulfidation. Increasing the concentration of the reagent and sulfidation time from 3 hours to 24 hours resulted in high percentages of sulfur-to-iron (S/Fe) for each material. This increase in S/Fe had a significant impact on the removal of cadmium and chromium as with higher the percentage of S/Fe, the faster the removal of these species occurred. Compared to pristine nZVI@misi, S-nZVI@misi was significantly faster at removing both cadmium and chromium. However, sulfidation of nZVI@misi proved to reduce the rate of 4-nitrophenol reduction and prevent nitrate reduction from occurring. Experimental analysis also showed that cadmium removal was faster with S-nZVI supported by FeOOH-coated microsilica, compared to material supported by un-coated microsilica. Therefore, we have synthesised supported S-nZVI that quickly removes cadmium and chromium from solution compared to standard supported nZVI.</p>

HPLC Analysis of the Urinary Iodine Concentration in Pregnant Women

Iodine is an essential component for fetal neurodevelopment and maternal thyroid function. Urine iodine is the most widely used indicator of iodine status. In this study, a novel validated ion-pair HPLC–UV method was developed to measure iodine concentration in clinical samples. A sodium thiosulfate solution was added to the urine sample to convert the total free iodine to iodide. Chromatographic separation was achieved in a Pursuit XRs C8 column. The mobile phase consisted of acetonitrile and a water phase containing 18-crown-6-ether, octylamine and sodium dihydrogen phosphate. Validation parameters, such as accuracy, precision, limits of detection and quantification, linearity and stability, were determined. Urinary samples from pregnant women were used to complete the validation and confirm the method’s applicability. In the studied population of 93 pregnant women, the median UIC was lower in the group without iodine supplementation (117 µg/L, confidence interval (%CI): 95; 138) than in the supplement group (133 µg/L, %CI: 109; 157). In conclusion, the newly established ion-pair HPLC–UV method was adequately precise, accurate and fulfilled validation the criteria for analyzing compounds in biological fluids. The method is less complicated and expensive than other frequently used assays and permits the identification of the iodine-deficient subjects.