Evaluation of high dose N- Acetylcysteine on airway inflammation and quality of life outcomes in adults with bronchiectasis: A randomised placebo-controlled pilot study

BACKGROUND

High dose N acetylcysteine (NAC), a mucolytic, anti-inflammatory and antioxidant agent has been shown to significantly reduce exacerbations, and improve quality of life in placebo controlled, double blind randomised (RCT) studies in patients with COPD, and in an open, randomised study in bronchiectasis. In this pilot, randomised, double-blind, placebo-controlled study, we wished to investigate the feasibility of a larger clinical trial, and the anti-inflammatory and clinical benefits of high dose NAC in bronchiectasis.

AIMS

Primary outcome: to assess the efficacy of NAC 2400 mg/day at 6 weeks on sputum neutrophil elastase (NE), a surrogate marker for exacerbations. Secondary aims included assessing the efficacy of NAC on sputum MUC5B, IL-8, lung function, quality of life, and adverse effects.

METHODS

Participants were randomised to receive 2400 mg or placebo for 6 weeks. They underwent 3 visits: at baseline, week 3 and week 6 where clinical and sputum measurements were assessed.

RESULTS

The study was stopped early due to the COVID pandemic. In total 24/30 patients were recruited, of which 17 completed all aspects of the study. Given this, a per protocol analysis was undertaken: NAC (n = 9) vs placebo (n = 8): mean age 72 vs 62 years; male gender: 44% vs 50%; baseline median FEV11.56 L (mean 71.5 % predicted) vs 2.29L (mean 82.2% predicted). At 6 weeks, sputum NE fell by 47% in the NAC group relative to placebo (mean fold difference (95%CI: 0.53 (0.12,2.42); MUC5B increased by 48% with NAC compared with placebo. Lung function, FVC improved significantly with NAC compared with placebo at 6 weeks (mean fold difference (95%CI): 1.10 (1.00, 1.20), p = 0.045. Bronchiectasis Quality of life measures within the respiratory and social functioning domains demonstrated clinically meaningful improvements, with social functioning reaching statistical significance. Adverse effects were similar in both groups.

CONCLUSION

High dose NAC exhibits anti-inflammatory benefits, and improvements in aspects of quality of life and lung function measures. It is safe and well tolerated. Further larger placebo controlled RCT's are now warranted examining its role in reducing exacerbations.

Management of hepatic hydropericardium with open drainage, maximal medical therapy and terlipressin

We present the case of a woman in her 60s with Child-Pugh C cirrhosis who developed pericardial tamponade during an admission for a haemothorax secondary to a mechanical fall. The patient developed haemodynamic compromise with a rapid decline in renal function. During an open subxiphoid drain tube insertion, a pre-existing peritoneopericardial communication was noted, with ascites in the peritoneal cavity on view. The serum ascites albumin gradient was 14 g/L. Maximal medical therapy was commenced including diuresis and albumin, with adjunctive terlipressin infusion which restored her baseline renal function and resolved the effusion. We believe this is the first case report of using open drainage, maximal medical therapy and terlipressin to successfully treat hepatic hydropericardium and its subsequent renal compromise.

Healthcare utilisation and costing for decompensated chronic liver disease hospitalisations at a Victorian network

BACKGROUND

The economic burden of decompensated chronic liver disease (CLD) on Australian healthcare services is poorly characterised.

AIMS

To evaluate the in-patient healthcare utilisation costs associated with decompensated CLD at Monash Health, an Australian tertiary healthcare service.

METHODS

The current retrospective cost analysis examined patients with decompensated CLD admitted between 1 January 2012 and 31 December 2018. Hospitalisations were identified using CLD-specific International Classification of Diseases, Tenth Revision, codes. Cost measures were estimated using the Victorian Weighted Inlier Equivalent Separation funding data based on the Australian Refined Diagnosis Related Groups cost weights.

RESULTS

There were 707 hospitalisations in 435 adult patients. The mean age was 56.7 ± 11.7 years and the mean length of stay was 10.28 ± 11.2 days. Median survival was 31 months (interquartile range, 2-94 months) and 177 (40.8%) patients died within 1 year of admission. The cost of admission varied according to decompensation: hepatorenal syndrome ($20 162 AUD), variceal bleed ($16 630 AUD), spontaneous bacterial peritonitis ($12 664 AUD), hepatic encephalopathy ($9973 AUD) and ascites ($9001 AUD). There was no significant difference in the admissions or 30-day readmission rate from 2012 to 2018 financial year (FY). The total adjusted cost of cirrhotic admissions per year increased by 78% from FY2012 to FY2018.

CONCLUSION

Hospital admission and readmission for decompensated CLD is common and associated with 40.8% 1-year mortality and high costs. Clearer delineation of goals of care and alternative ambulatory care models for decompensated CLD are urgently required to reduce the high costs and burden on health services.

A Beta-Prototype Chatbot for Increasing Health Literacy of Patients With Decompensated Cirrhosis: Usability Study

BACKGROUND

Health literacy is low among patients with chronic liver disease (CLD) and associated with poor health outcomes and increased health care use. Lucy LiverBot, an artificial intelligence chatbot was created by a multidisciplinary team at Monash Health, Australia, to improve health literacy and self-efficacy in patients with decompensated CLD.

OBJECTIVE

The aim of this study was to explore users' experience with Lucy LiverBot using an unmoderated, in-person, qualitative test.

METHODS

Lucy LiverBot is a simple, low cost, and scalable digital intervention, which was at the beta prototype development phase at the time of usability testing. The concept and prototype development was realized in 2 phases: concept development and usability testing. We conducted a mixed methods study to assess usability of Lucy LiverBot as a tool for health literacy education among ambulatory and hospitalized patients with decompensated CLD at Monash Health. Patients were provided with free reign to interact with Lucy LiverBot on an iPad device under moderator observation. A 3-part survey (preuser, user, and postuser) was developed using the Unified Acceptance Theory Framework to capture the user experience.

RESULTS

There were 20 participants with a median age of 55.5 (IQR 46.0-60.5) years, 55% (n=11) of them were female, and 85% (n=17) of them were White. In total, 35% (n=7) of them reported having difficulty reading and understanding written medical information. Alcohol was the predominant etiology in 70% (n=14) of users. Participants actively engaged with Lucy LiverBot and identified it as a potential educational tool and device that could act as a social companion to improve well-being. In total, 25% (n=5) of them reported finding it difficult to learn about their health problems and 20% (n=4) of them found it difficult to find medical information they could trust. Qualitative interviews revealed the conversational nature of Lucy LiverBot was considered highly appealing with improvement in mental health and well-being reported as an unintended benefit of Lucy LiverBot. Patients who had been managing their liver cirrhosis for several years identified that they would be less likely to use Lucy LiverBot, but that it would have been more useful at the time of their diagnosis. Overall, Lucy LiverBot was perceived as a reliable and trustworthy source of information.

CONCLUSIONS

Lucy LiverBot was well received and may be used to improve health literacy and address barriers to health care provision in patients with decompensated CLD. The study revealed important feedback that has been used to further optimize Lucy LiverBot. Further acceptability and validation studies are being undertaken to investigate whether Lucy LiverBot can improve clinical outcomes and health related quality of life in patients with decompensated CLD.

A home-based, multidisciplinary liver optimisation programme for the first 28 days after an admission for acute-on-chronic liver failure (LivR well): a study protocol for a randomised controlled trial

Background

Acute-on-chronic liver failure (ACLF) represents a rising global healthcare burden, characterised by increasing prevalence among patients with decompensated cirrhosis who have a 28-day transplantation-free mortality of 33.9%. Due to disease complexity and a high prevalence of socio-economic disadvantage, there are deficits in quality of care and adherence to guideline-based treatment in this cohort. Compared to other chronic conditions such as heart failure, those with liver disease have reduced access to integrated ambulatory care services. The LivR Well programme is a multidisciplinary intervention aimed at improving 28-day mortality and reducing 30-day readmission through a home-based, liver optimisation programme implemented in the first 28 days after an admission with either ACLF or hepatic decompensation. Outcomes from our feasibility study suggest that the intervention is safe and acceptable to patients and carers.

Methods

We will recruit adult patients with chronic liver disease from the emergency departments, in-patient admissions, and an ambulatory liver clinic of a multi-site quaternary health service in Melbourne, Australia. A total of 120 patients meeting EF-Clif criteria will be recruited to the ACLF arm, and 320 patients to the hepatic decompensation arm. Participants in each cohort will be randomised to the intervention arm, a 28-day multidisciplinary programme or to standard ambulatory care in a 1:1 ratio. The intervention arm includes access to nursing, pharmacy, physiotherapy, dietetics, social work, and neuropsychiatry clinicians. For the ACLF cohort, the primary outcome is 28-day mortality. For the hepatic decompensation cohort, the primary outcome is 30-day re-admission. Secondary outcomes assess changes in liver disease severity and quality of life. An interim analysis will be performed at 50% recruitment to consider early cessation of the trial if the intervention is superior to the control, as suggested in our feasibility study. A cost-effectiveness analysis will be performed. Patients will be followed up for 12 weeks from randomisation. Three exploratory subgroup analyses will be conducted by (a) source of referral, (b) unplanned hospitalisation, and (c) concurrent COVID-19. The trial has been registered with the Australian New Zealand Clinical Trials Registry.

Discussion

This study implements a multidisciplinary intervention for ACLF patients with proven benefits in other chronic diseases with the addition of novel digital health tools to enable remote patient monitoring during the COVID-19 pandemic. Our feasibility study demonstrates safety and acceptability and suggests clinical improvement in a small sample size. An RCT is required to generate robust outcomes in this frail, high healthcare resource utilisation cohort with high readmission and mortality risk. Interventions such as LivR Well are urgently required but also need to be evaluated to ensure feasibility, replicability, and scalability across different healthcare systems. The implications of this trial include the generalisability of the programme for implementation across regional and urban centres.

Trial registration

Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12621001703897. Registered on 13 December 2021.

WHO Trial Registration Data Set. See Appendix 1

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06679-x.

Pyopneumopericarditis from a gastropericardial fistula: a case report

Background

Pyopneumopericarditis is a very rare diagnosis that requires prompt recognition and urgent treatment. It denotes the presence of pus and air in the pericardium with associated inflammation of the fibrous pericardial sac.

Case summary

A 49-year-old gentleman was admitted with pyopneumoperciarditis on a background of a previous uncomplicated Roux-en-Y gastric bypass surgery performed 7 years prior. He underwent emergency surgery for an omental patch repair of an ulcer perforation involving the diaphragm and pericardium. His inpatient stay was complicated by persistent seropurulent output from the pericardial drain, loculated pleural effusion, and deconditioning.

Discussion

Management is extrapolated from the literature regarding purulent pericarditis. This condition albeit rare, requires swift recognition as without treatment mortality approaches 100%. Colchicine is an important adjunctive therapy postoperatively to prevent constrictive physiology.

Metal stents are safe and cost-effective for preoperative biliary drainage in resectable pancreaticobiliary tumours

BACKGROUNDS

To compare the complication rates and overall costs of self-expandable metal stents (SEMS) and plastic stents (PS) in clinically indicated preoperative biliary drainage (PBD) prior to a pancreatoduodenectomy (PD).

METHODS

We conducted an Australian multicentre retrospective cohort study using the databases of four tertiary hospitals. Adult patients who underwent clinically indicated endoscopic PBD prior to PD from 2010 to 2019 were included. Rates of complications attributable to PBD, surgical complications and pre-operative endoscopic re-intervention were calculated. Costing data were retrieved from our Financial department.

RESULTS

Among the 157 included patients (mean age 66.6 ± 9.8 years, 45.2% male), 49 (31.2%) received SEMS and 108 received PS (68.8%). Baseline bilirubin was 187.5 ± 122.6 μmol/L. Resection histopathology showed mainly adenocarcinoma (93.0%). Overall SEMS was associated less complications (12.2% vs. 28.7%, p = 0.02) and a lower pre-operative endoscopic re-intervention rate (4.3 vs. 20.8%, p = 0.03) compared with PS. There was no difference in post-PD complication rates. On multivariate logistic regression analysis, stent type was an independent risk factor of PBD complication (OR of SEMS compared to PS 0.24, 95% CI 0.07-0.79, p = 0.02) but not for any secondary outcome measures. Upfront material costs were $56USD for PS and $1991USD for SEMS. Accounting for rates of complications, average costs were similar ($3110USD for PS and $3026USD for SEMS).

CONCLUSION

In resectable pancreaticobiliary tumours, SEMS for PBD was associated with reduced risk of overall PBD-related complications and pre-surgical endoscopic reintervention rates and was comparable to PS in terms of overall cost.

Population pharmacokinetics of ceftazidime in critically ill children: impact of cystic fibrosis

BACKGROUND

Pharmacokinetics data on ceftazidime are sparse for the paediatric population, particularly for children with cystic fibrosis (CF) or severe infections.

OBJECTIVES

To characterize the population pharmacokinetics of ceftazidime in critically ill children, identify covariates that affect drug disposition and evaluate the current dosing regimens.

METHODS

The study was registered with Clinicaltrials.gov (NCT01344512). Children receiving ceftazidime were selected in 13 French hospitals. Plasma concentrations were determined by UPLC-MS/MS. Population pharmacokinetic analyses were performed using NONMEN software.

RESULTS

One hundred and eight patients, aged 28 days to 12 years, with CF (n = 32), haematology and/or oncology disorders (n = 47) or severe infection (n = 29) were included. Ceftazidime was administered by continuous or intermittent infusions; 271 samples were available for analysis. A two-compartment model with first-order elimination and allometric scaling was developed and covariate analysis showed that ceftazidime pharmacokinetics were also significantly affected by CLCR and CF. Ceftazidime clearance was 82% higher in CF than in non-CF patients. Monte Carlo simulations showed that the percentage of target attainment (PTA) for the target of T>MIC = 65% was (i) lower in CF than in non-CF children with intermittent infusions and (ii) higher with continuous than intermittent infusion in all children.

CONCLUSIONS

The population pharmacokinetics model for ceftazidime in children was influenced by body weight, CLCR and CF. A higher PTA was obtained with continuous versus intermittent infusions. Further studies should explore the benefits of continuous versus intermittent infusion of ceftazidime, including current versus increased doses in CF children.

Implementation of an Educational iPad Application for Patients With Chronic Hepatitis B

Chronic Hepatitis B (CHB) contributes to a high public health burden in Australia from chronic liver disease and hepatocellular carcinoma. Health literacy impacts on multiple aspects of long term management, including surveillance and long term follow up. We designed and implemented a multilingual educational iPad application for outpatients to use while in the clinic waiting room. The application employed an interactive and multimodal approach to education. It utilized graphics, audio and text to convey practical information regarding transmission of disease, long term complications, treatment and surveillance. Participants were recruited from a tertiary liver clinic and assigned to either standard treatment (routine clinical consult only) or the iPad group (clinical consult and additional education with the iPad app). There were 54 participants (control n = 29, iPad n = 25). Knowledge was assessed at baseline, secondly after the clinician appointment and finally at 6 months. Median follow up time was 6.1 months (range 0–18 months) and 87% of participants completed the final survey. At baseline, there was no difference in age, gender, proportion of newly referred patients, or use of antivirals. Baseline knowledge was similar in the two groups (61.4 vs. 55.1%, p = 0.33). The iPad group scored significantly higher after the first consult (79.5 vs. 61.5%, p = 0.0005). This improvement remained significant by the end of follow up (72.6 vs. 61.0%, p = 0.0472). To conclude, interactive education with iPads may be an effective way to improve patient knowledge.

Parent satisfaction with primary repair of paediatric cleft lip in Southwest China

The purpose of this study was to investigate the key factors in relation to parent satisfaction with the primary repair of paediatric cleft lip. One hundred and ninety-five children born with cleft lip and/or palate aged between 3 months and 1 year were recruited, along with their caregivers. All patients underwent primary cleft lip repair, and a telephone interview was held with their main caregivers at 3 months postoperative. The level of satisfaction with each item included in a simplified Cleft Evaluation Profile was ascertained and recorded. Patient clinical data were obtained from the medical records. One hundred and thirty-eight (71%) parents reported satisfaction with the general outcome of surgery. Parents were satisfied with the appearance of the lip and profile of the face, but were dissatisfied with the appearance of the nose and teeth. Mothers of patients showed lower satisfaction levels than fathers and grandparents. Parental satisfaction with the appearance of the lip was lower for patients without a cleft palate than for those with a cleft palate. The results of this study suggest that most Chinese parents of children who undergo primary cleft lip repair express satisfaction with the surgical outcomes. Satisfaction with the appearance of the nose and teeth is low and this needs to be improved. Other factors are likely to influence expressions of satisfaction.

BRG1, a component of the SWI-SNF complex, is mutated in multiple human tumor cell lines

Human BRG1 is a component of the evolutionarily conserved SWI-SNF chromatin remodeling complex. BRG1 has been implicated in growth control through its interaction with the tumor suppressor pRb and may consequently serve as a negative regulator of proliferation. Postulating that BRG1 may itself be a tumor suppressor gene, we screened a panel of tumor cell lines to determine whether the gene is targeted for mutation. We report that the COOH-terminal region of BRG1 is homozygously deleted in two carcinoma cell lines, prostate TSU-Pr1 and lung A-427. In addition, biallelic inactivations of BRG1 were observed in four other cell lines derived from carcinomas of the breast, lung, pancreas, and prostate; their mutations in BRG1 included three frameshift lesions and one nonsense lesion. Point mutations were also discovered in a number of other cell lines, however in most cases any effect of these mutations on BRG1 function remains to be established. A variety of different mutations within BRG1, in several cell lines, suggest that BRG1 may be targeted for disruption in human tumors. Significantly, reintroduction of BRG1 into cells lacking BRG1 expression was sufficient to reverse their transformed phenotype inducing growth arrest and a flattened morphology. These data strongly support the model that BRG1 may function as a tumor suppressor and strengthen the hypothesis that the regulation of gene expression through chromatin remodeling is critical for cancer progression. It will be important to confirm these observations in primary tumors.

Selenium supplementation affects the retention of stable isotopes of selenium in human subjects consuming diets low in selenium

Twenty-nine women and fifteen men from an area of low Se intake (South Island of New Zealand) consumed 100 micrograms stable 74Se, as selenate given in water after an overnight fast, and blood was collected for 3 weeks. They were then divided into five groups and supplemented with 0, 10, 20, 30 and 40 micrograms Se/d (as selenomethionine) for 5 months. After 5 months, they received a second dose of 74Se identical to the first. Supplementation significantly altered retention of 74Se in the plasma, but not in the erythrocytes or platelets. Subjects receiving the placebo retained the greatest amount, and subjects receiving 30 micrograms supplemental Se/d retained the least 74Se. Supplementation resulted in relatively more isotope being retained in a medium molecular mass protein considered to be albumin, and relatively less in another fraction considered to be selenoprotein P. The lack of many observed changes in retention of stable Se, and the shift in retention among the plasma proteins, suggests that supplemental Se was not being used to replete critical pools of Se, probably because of adaptation to low Se intake.

Metabolism of selenite in men with widely varying selenium status

OBJECTIVE

This study was undertaken to investigate the metabolism of selenite in men with life-long intakes of deficient, adequate and excess selenium.

METHODS

Stable isotopes of selenium were infused for five hours into Chinese men living in deficient, adequate or excessive selenium areas, and 24-hour urine and blood samples were collected daily for the next seven days. Stable isotopic selenium excretion was determined in urine and in whole plasma and plasma fractions.

RESULTS

Even though there was a positive correlation of selenium intake with the urinary excretion of this element, this relationship was not linear over the entire range (deficient, adequate, excessive) of selenium intake. When the urine excretion was normalized internally within each group, a sharp increase in the slope of this relationship was found when long-term intake increased to adequate amounts, but the slope reached a plateau when the daily intake exceeded the adequate group. The plasma selenoprotein P fraction was labeled initially, but the incorporation in the glutathione peroxidase fraction subsequently increased by a small amount. A two-month dietary restriction of selenium of the subjects from the excess area did not result in a reduction of urinary excretion of infused selenite.

CONCLUSION

A complex relationship exists between long-term intake of selenium and selenium status, and subjects living in the excess area are more saturated with selenium than anticipated. More than two months of depletion are required to affect urinary excretion of selenium.

Effect of dietary selenium restriction on selected parameters of selenium status in men with high life-long intake11Published with the approval of the Oregon State University Agricultural Experiment Station as Technical Paper number 11,383

The influence of selenium (Se) restriction on disposition in plasma and urine fractions of infused (74)Se (selenite) was studied when adult males (Enshi City, Hubei Province, PRC) whose habitual daily Se intake is approximately 480 microg per day were transferred to Lichuan County, where the daily intake is approximately 30 microg. The subjects received an infusion (106 microg Se) on the day before consuming foods low in Se and a second infusion (113 microg Se) 63 days later. Blood and 24-hour urine samples were collected each day for 7 days after the first infusion and on days 22, 43, and 62 following the first infusion. Urine and blood were also collected daily for the next 7 days after the second infusion. Plasma total Se concentration increased for 7 days after each of the two infusions and urine Se decreased exponentially following both the first and second infusions. The excretion of trimethylselenonium followed the same pattern as the total urinary Se. Surprisingly, there was not a significant difference in selenite retention between the two infusion periods, and the data indicated that, regardless of the chemical form of Se present in various organs, its catabolism leading to excretion in urine followed the same pathway as that of selenite. Labeled Se was incorporated predominantly in the plasma selenoprotein P fraction and the half-life of Se in this fraction was determined to be 1.9 to 2.9 days. Thus, a longer depletion period is required in these subjects to obtain more significant changes.

Quantitative significance of measuring trimethylselenonium in urine for assessing chronically high intakes of selenium in human subjects

The purpose of the present study was to investigate the effects of Se restriction on the excretion of Se in men who had consumed high levels of this element during their entire lives. With the use of stable isotopes of Se as selenite, the excretion of methylated Se in urine was investigated in Chinese men (n 10) who had habitual chronic high intakes of this element. The relationship between either urine Se or trimethylselenonium (TMSe) to the estimated long-term Se intake was not linear over the entire range of intake, which was also true for the infusion of labelled selenite. A non-linear relationship was also found between urine TMSe and urine Se both for TMSe arising from catabolism of endogenous body Se and that from infused selenite. The data suggest a close precursor-product relationship of urine Se and its TMSe component based on the nearly identical specific activities for these two selenocompounds. Although dimethylselenide in breath was not measured in the present study, combining urinary TMSe with this breath test may be more useful in the assessment of long-term Se status.

Characterization of a carboxy-terminal BRCA1 interacting protein

There are several lines of evidence indicating that the carboxy-terminal region of the tumor suppressor protein BRCA1 is a functionally significant domain. Using the yeast two-hybrid and in vitro biochemical assays, we show that a protein, CtIP, interacts specifically with the carboxy-terminal segment of human BRCA1 from residues 1602-1863. A germ line truncation mutation, Y1853ter, that removes the last 11 amino acids from the carboxy-terminus of BRCA1, abolishes not only its transcriptional activation function, but also binding to CtIP. The function of CtIP is unknown, but its reported association with a transcriptional repressor CtBP lends further support that it may have a role in transcription. A sequence based screen of a panel of 89 tumor cell line cDNAs for mutations in the CtIP coding region identified five missense variants. In the pancreatic carcinoma cell line, BxPC3, the non-conservative lysine to glutamic acid change at codon 337 is accompanied with apparent loss of heterozygosity or non-expression of the wild type allele. Thus it is plausible that CtIP may itself be a tumor suppressor acting in the same pathway as BRCA1.

[Determination of the selenomethionine content in grain and human blood]

The authors used the method of cyanogen bromide-fulorimetry to determine the trace amounts of bound selenomethionine (SeMet) in corn, rice, wheat, soybean and human blood. The contents of SeMet in corn samples were found to be 9.2-19014.1 ng/g, and 45.5% to 82% of the total Se in corn samples were in the form of SeMet. Like corn, the proportion of Se in the form of SeMet in total Se in rice, wheat and soybean were 54.9%-86.5%, 50.4%-81.4% and 62.9%-71.8% respectively. The results showed that SeMet is the major chemical form of Se in grain samples determined. The contents of SeMet in two human blood samples (Se content 56.4 ng/g and 71.8 ng/g) were determined as 28.3 ng/g and 53.4 ng/g respectively.

[Method of cyanogen bromide-fluorimetry determination of trace amount of selenomethionine in grain and blood]

Selenomethionine (SeMet) reacted with cyanogen bromide (BrCN) quantitatively forms CH3SeCN. After extracted with CHCl3, the Se of CH3SeCN is acid-digested to Se(IV). Then 2,3-diaminonaphthalene is used to determine the fluorescent Se value of 4,5-benzopiaselenol. The determination limit of this method was 3 ng/g SeMet. The accuracy of 10-500 ng Se in SeMet standard was 91.8%-97.6%. RSD was 1.9%-6.3%. Recoveries for grain and blood were 92.3%-96.7%. RSD was 2.7%-5.1%. The RSD for samples was 2.7%-9.0%. Selenocystine, selenocystiene selenite and methionine did not interfere with the determination.