Severe acute renal failure due to bromate intoxication: report of a case and discussion of management guidelines based on a review of the literature

Cochlear Implantation after Bromate Intoxication-Induced Bilateral Deafness: A Case Report

Hearing loss is a common consequence of the strong acidosis induced by bromate poisoning. Partial hearing recovery has been achieved through medical or rehabilitative therapy but reports of surgical otology treatment for this condition are rare. We report the case of a 48-year-old female patient who underwent cochlear implantation after bromate intoxication had induced bilateral deafness. In cases with life-threatening renal damage, the diagnosis of hearing loss is sometimes delayed, but in our case, hearing impairment was unavoidable despite early detection of symptoms and early disruption of the use of diuretics that could cause hearing damage. Hearing loss 12 hours after bromate ingestion was successfully reversed through cochlear implantation (CI) six months after completing acute phase treatment, including dialysis for acute kidney injury. The benefit of CI for deafness by bromate intoxication is highlighted by this case.

Potassium bromate: Effects on bread components, health, environment and method of analysis: A review

Potassium bromate, is an oxidizing agent and one of the best and cheapest dough improvers in the baking industry. Due to its positive effects it plays a major role in the bread-making industry. Potassium bromate has significant effect on food biomolecules, such as starch and protein, as it affects the extent of gelatinization, viscosity, swelling characteristics as well as gluten proteins; it removes the sulfhydryl group and leads to the formation of disulfide linkages and thus improves the bread properties. However, there are many reports elucidating its negative impact on human health. It is deemed as a potential human carcinogen by IARC and classified under class 2B. Due to this, countries across world have either partially or completely banned it. Numerous techniques have evolved to determine the concentration of potassium bromate in bread. This review explains in detail, the effects of potassium bromate on biomolecules, human health, environment and various methods of analysis.

Role of Platelet Surface Receptor Abnormalities in the Bleeding and Thrombotic Diathesis of Uremic Patients on Hemodialysis and Peritoneal Dialysis

Background

Patients with chronic renal failure suffer from bleeding diathesis and a tendency to accelerated atherosclerosis. Altered platelet function plays a well defined role in the hemorrhagic complications of these patients and has a probable impact on atherothrombotic disease in uremia. In this study we investigated the expression of platelet surface receptors, the glycoprotein GPIb (receptor for von Willebrand Factor(vWF) and GPIIb/IIIa (receptor for fibrinogen) in patient with chronic renal failure in pre-dialysis status, under hemodialysis and peritoneal dialysis treatment, in order to assess the impact of the abnormal receptorial status of uremic platelets on the clinical manifestations of hemostatic alterations in uremic patients.

Methods

Thirty-seven normal healthy subjects (controls = Group A), 18 patients with mild chronic renal failure (creatinine = 1.8 ± 0.5mg% - Group B), 15 patients with advanced renal failure (creatinine = 5.4 ± 2.1mg% - Group C), 18 hemodialysis patients (Group D) and 11 peritoneal dialysis patients (Group E) were included in the study. The expression of platelet surface receptors GPIb and GPIIb/IIIa was investigated with monoclonal antibodies CD42 and CD41 (Immunotech, Marseille, France) and a FACScan flowcytometer (Becton-Dickinson, USA).

Results

Mean values of GPIb glycoprotein (mean flow ± SD) were: group A = 48.14 ± 9.31; group B=40.48 ± 8.18 (p < 0.005); group C = 34.05 ± 7.55 (p < 0.0005) versus group A; p = 0.025 versus group B); group D = 34.51 ± 7.22 (p < 0.0005 versus group A; p = 0.025 group B and p = ns versus group C); group E = 26.34 ± 4.06 (p < 0.0005 versus group A, p < 0.0005 versus group B, p < 0.005 versus groups C and D). Mean values of glycoprotein GPIIb/IIIa were: group A = 375.32 ± 90.58; group B = 398.48 ± 54.26 (p = ns); group C = 426.86 ± 52.78 (p < 0.025 versus group A; p = ns versus group B); group D = 425.17 ± 75.03 (p < 0.025 versus group A; p = ns versus groups B and C); group E = 336.39 ± 43.26 (p = ns versus group A; p < 0.005 versus group B, p < 0.0005 versus group C and p < 0.001 versus group D).

Conclusions

Our data confirm the receptorial defect of glycoprotein GPIb (the receptor for vWF) on the surface of uremic platelets: a negative correlation between serum creatinine and the expression of glycoprotein GPIb was found. The defect was not corrected by hemodialysis and/or peritoneal dialysis. Hemodialysis and peritoneal dialysis have a different impact on the expression of GPIIb/IIIa glycoprotein (the receptor for vWF): peritoneal dialysis seems to have a more favourable effect by restoring normal values of the expression of this membrane integrine. Theoretically the data could be correlated to the better biocompatibility of the peritoneal dialysis and to more favorable clinical behaviour in terms of accelerated atherosclerosis and athero-thrombotic complications in the uremic patients with end stage renal disease. Finally the abnormalities of platelet surface receptors may play a main role in the hemostatic alterations of uremic patients.

Simultaneous removal of selected oxidized contaminants in groundwater using a continuously stirred hydrogen-based membrane biofilm reactor

A laboratory trial was conducted for evaluating the capability of a continuously stirred hydrogen-based membrane biofilm reactor to simultaneously reduce nitrate (NO(3-)-N), sulfate (SO4(2-)), bromate (BrO3-), hexavalent chromium (Cr(VI)) and parachloronitrobenzene (p-CNB). The reactor contained two bundles of hollow fiber membranes functioning as an autotrophic biofilm carrier and hydrogen pipe as well. On the condition that hydrogen was supplied as electron donor and diffused into water through membrane pores, autohydrogenotrophic bacteria were capable of reducing contaminants to forms with lower toxicity. Reduction occurred within 1 day and removal fluxes for NO(3-)-N, SO4(2-), BrO3-, Cr(VI), and p-CNB reached 0.641, 2.396, 0.008, 0.016 and 0.031 g/(day x m2), respectively after 112 days of continuous operation. Except for the fact that sulfate was 37% removed under high surface loading, the other four contaminants were reduced by over 95%. The removal flux comparison between phases varying in surface loading and H2 pressure showed that decreasing surface loading or increasing H2 pressure would promote removal flux. Competition for electrons occurred among the five contaminants. Electron-equivalent flux analysis showed that the amount of utilized hydrogen was mainly controlled by NO(3-)-N and SO4(2-) reduction, which accounted for over 99% of the electron flux altogether. It also indicated the electron acceptor order, showing that nitrate was the most prior electron acceptor while suIfate was the second of the five contaminants.

Acute kidney injury due to sodium bromate intoxication: a report of two cases

Sodium bromate is a strong oxidant used as a neutralizing solution in hair permanents, as well as an auxiliary agent in printing and dyeing. Accidental or deliberate ingestion of bromate solution has rarely been reported in Korea. The clinical manifestations of bromate intoxication are vomiting, diarrhea, central nervous system symptoms, oliguric or non-oliguric acute kidney injury, hemolytic anemia, and deafness; most of these manifestations are reversible, with the exception of renal failure and deafness. Here, we report on two patients who demonstrated distinct clinical progressions. In the first case, a 16-year-old woman was successfully treated with hemodialysis and recovered renal function without hearing loss. However, in the second case, delayed hemodialysis resulted in persistent renal failure and hearing loss in a 77-year-old woman. This suggests that emergency therapeutic measures, including hemodialysis, should be taken as soon as possible, as the rapid removal of bromate may be essential to preventing severe intoxication and its sequelae.

Bromate-induced ototoxicity

For decades, it has been known that ingested potassium bromate and sodium bromate can induce hearing loss. Hearing loss onset, following high-dose ingestion, is generally rapid occurring within 4-16 h and of a severe to profound degree. Unlike the sensorineural hearing loss which is generally irreversible, bromate-induced tinnitus, which is less well-studied, may reportedly be permanent or temporary. It is not clear whether actual bromate-induced vestibulotoxicity occurs in clinical populations. The primary sites of lesion for bromate-induced ototoxicity appear to be in the cochlea. However, possible effects on the VIIIth nerve and central auditory system have not been fully investigated. Based on animal studies, in the cochlea, bromate damages the stria vascularis, Reissner's membrane, inner and outer hair cells, Claudius cells and inner sulcus cells. Physiologically, bromate reduces the endocochlear potential, cochlear microphonics, and electrophysiologic auditory thresholds. Possible mechanisms are discussed. The effects of long-term low-dose bromate exposure on hearing have not been studied. These effects, if they occur, may not be readily detected in many clinical populations, because idiopathic hearing loss occurs commonly in the population as a whole. Further it is unknown whether or not chronic bromate ingestion may exacerbate noise-induced hearing loss. Further study to determine the maximum safe exposure level for long-term administration and to develop possible antidotes is warranted.

An elderly patient with severe acute renal failure due to sodium bromate intoxication

Accidental or deliberate ingestion of bromate solution has been reported in pediatric as well as adult cases; however there have been no reports of such intoxication in the elderly. We report a 78-year-old woman who suffered severe acute renal failure due to the accidental ingestion of sodium bromate solution. The patient was successfully treated with hemodialysis therapy and renal function recovered without hearing loss. This case suggests that emergency therapeutic measures, including hemodialysis, should be taken as soon as possible, and the rapid removal of bromate is essential to prevent severe intoxication and its sequelae. To the best of our knowledge this is the first report of an elderly patient that demonstrates the clinical benefit of hemodialysis therapy for bromate intoxication.

Sodium thiosulfate fails to reduce nitrite-induced methemoglobinemia in vitro

OBJECTIVES

To determine whether sodium thiosulfate (STS) produces a clinically significant decline in sodium nitrite-induced methemoglobinemia in an in-vitro model.

METHODS

This was an in-vitro, controlled study where methemoglobinemia was induced by the addition of sodium nitrite (0.4 mg/mL) to 35-mL aliquots of blood obtained from ten healthy volunteers. Methemoglobin (MetHb) concentrations were measured at 5-minute intervals for 30 minutes by co-oximetry, and each aliquot was then subdivided into six 5-mL samples (time zero). Sample 1 served as control. The remaining samples received serial dilutions of STS (0.125 mg, 1.25 mg, 12.5 mg, 125 mg, 1,250 mg). MetHb concentrations were measured by co-oximetry at baseline, 0, 15, 30, 45, and 60 minutes. Areas under the MetHb concentration-time curve (AUC) between time zero and 60 minutes were compared using the Kruskal-Wallis test.

RESULTS

Methemoglobin concentrations increased from 0.07 g/dL (+/-0.06) at baseline to 8.42 g/dL (+/-0.69) at time 0 (the addition of STS). No significant difference was detected between baseline and time 0 hemoglobin concentrations (15.8 +/- 0.5 vs. 16.1 +/- 0.6 g/dL). There was no detectable difference found between the AUCs (measured in g min/dL) of any of the STS serial dilutions or control groups (0.125 mg STS = 576.01 +/- 42.53; 1.25 mg STS = 573.47 +/- 40.82; 12.5 mg STS = 583.68 +/- 42.29; 125 mg STS = 554.75 +/- 42.68; 1,250 mg STS = 566.95 +/- 38.08; p = 0.81).

CONCLUSIONS

Sodium thiosulfate was not found to be an effective reducing agent for the acute treatment of methemoglobinemia.

Mutations in the VHL gene from potassium bromate-induced rat clear cell renal tumors

Potassium bromate (KBrO(3)) is a rat renal carcinogen and a major drinking water disinfection by-product in water disinfected with ozone. Clear cell renal tumors, the most common form of human renal epithelial neoplasm, are rare in animals but are inducible by KBrO(3) in F344 rats. Detection of cytoplasmic periodic acid-Schiff-positive granules in clear cell tumors, indicative of glycogen accumulation, provides evidence of their biochemical similarity to human counterparts. Mutation in the coding region of the von Hippel-Lindau (VHL) gene is frequently detected in human clear cell renal carcinomas. Detection of VHL mutations in KBrO(3)-induced rat renal tumors could enhance the relevancy of these rat renal tumors for human health risk assessment. Formalin-fixed paraffin-embedded control tissues and renal tumors from male F344 rats exposed to KBrO(3) in the drinking water for 2 years were examined microscopically and were microdissected for DNA extraction. The coding sequence and a promoter region of the VHL gene were examined by polymerase chain reaction-single strand conformation polymorphism and/or DNA sequencing. Two of nine clear cell renal tumors carried the same C to T mutation at the core region of the Sp1 transcription factor binding motif in the VHL promoter and one of four untreated animals had C to T mutation outside the highly conserved core region. Mutation in the VHL coding sequence was only detected in one tumor. No VHL mutations were observed in three chromophilic tumors. KBrO(3)-induced rat renal tumors are morphologically similar to their human counterpart but the genetic basis of tumorigenesis is different.

Contribution of nitric oxide to potassium bromate-induced elevation of methaemoglobin concentration in mouse blood

Bromate, an inorganic oxyhalide disinfection by-product, is known to cause kidney damage, haemolysis and methaemoglobinemia. In potassium bromate (KBrO3)-treated mice (1.2 mmol/kg), elevation of methaemoglobin (MetHb) concentration in blood was observed simultaneously with an elevation of the NO concentration and attenuation of glutathione peroxidase (GPx) activity. Renal oxidative stress and kidney damage were also confirmed in the KBrO3-treated mice. A pre-administered GPx-mimic ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one) dose-dependently diminished the KBrO3-induced changes in MetHb concentration and GPx activity. Renal oxidative stress and kidney damage caused by the KBrO3 administration were also dose-dependently suppressed by ebselen. On the other hand, ebselen did not suppress the KBrO3-induced elevation of the NO concentration. KBrO3-induced methaemoglobinemia, renal oxidative stress and kidney damage, consequently, seemed to result from the attenuation of GPx activity. Besides, the enhancement of NO production was not likely to be a result but a cause for the KBrO3-induced attenuation of GPx activity. In in vitro experiments, oxidation of human oxyhaemoglobin (HbO2) to MetHb was observed in a reaction mixture containing HbO2 and an NO donor, NOC-7 (1-hydroxy-2-oxo-3-(N-methyl-3-aminopropyl)-3-methyl-1-triazene) or SIN-1 (3-(4-morpholinyl)sydnonimine), and this oxidation was inhibited by the NO scavenger carboxy-PTIO (2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide). However, no MetHb formation was observed in a reaction mixture containing HbO2 and KBrO3. These results suggest that KBrO3-induced methaemoglobinemia results from the reduction of GPx activity in blood by the KBrO3-induced increases in superoxide, NO and ONOO-.

Carcinogenicity of potassium bromate administered in the drinking water to male B6C3F1 mice and F344/N rats

Ozone has been proposed for water disinfection because it is more efficient than chlorine for killing microbes and results in much lower levels of carcinogenic trihalomethanes than does chlorination. Ozone leads to formation of hypobromous acid in surface waters with high bromine content and forms brominated organic by-products and bromate. The carcinogenicity and chronic toxicity of potassium bromate (KBrO3) was studied in male B6C3F1 mice and F344/N rats to confirm and extend the results of previous work. Mice were treated with 0, 0.08, 0.4, or 0.8 g/L KBrO3 in the drinking water for up to 100 wk, and rats were provided with 0, 0.02, 0.1, 0.2, or 0.4 g/L KBrO3. Animals were euthanatized, necropsied, and subjected to a complete macroscopic examination. Selected tissues and gross lesions were processed by routine methods for light microscopic examination. The present study showed that KBrO3 is carcinogenic in the rat kidney, thyroid, and mesothelium and is a renal carcinogen in the male mouse, KBrO3 was carcinogenic in rodents at water concentrations as low as 0.02 g/L (20 ppm; 1.5 mg/kg/day). These data can be used to estimate the human health risk that would be associated with changing from chlorination to ozonation for disinfection of drinking water.