Index serum hyaluronic acid independently and accurately predicts mortality in patients with liver disease.

BACKGROUND: Hyaluronic acid is a recognised noninvasive marker of liver fibrosis. However, its prognostic ability has not been extensively studied. AIMS: To investigate the ability of an index serum hyaluronic acid measurement to independently predict transplant-free survival in patients with liver disease of varying aetiology and severity. METHODS: This was a retrospective single-centre cohort study. Serum hyaluronic acid was measured at the discretion of the attending clinicians, in patients attending the liver clinic, to assess disease severity. Patients with a hyaluronic acid measurement between 1995 and 2010 were identified. Patient characteristics at the point of hyaluronic acid measurement were recorded from medical records. Follow-up was from date of index hyaluronic acid measurement to date of death, date of transplant or censor date (July 01, 2015). Primary outcomes were all-cause and liver-related mortality. Kaplan-Meier analysis was used to compare survival in 3 patient groups with hyaluronic acid levels of <100 µg/L, 100-300 µg/L and >300 µg/L. Survival models were constructed using Cox proportional hazard and prediction accuracy was assessed by Harrell's C-statistic. RESULTS: Five hundred and eighty nine patients fulfilled inclusion criteria. Median follow-up was 5.6 years (range 0.1-19.7). Transplant-free survival was significantly different between patients with hyaluronic acid <100 µg/L, 100-300 µg/L and >300 µg/L for liver-related as well as all-cause mortality (P < 0.001). Hyaluronic acid level was an independent predictor of survival (liver-related: HR 1.39, 95% CI 1.20-1.60, P < 0.001; all-cause: HR 1.04, 95% CI 1.02-1.06, P = 0.001). The liver-related prediction accuracy of hyaluronic acid was 0.74 (Standard error 0.03). CONCLUSION: Index hyaluronic acid measurement can accurately and independently predict liver-related and all-cause mortality in patients with liver disease.

Combined dysfunctions of immune cells predict nosocomial infection in critically ill patients.

BACKGROUND: Nosocomial infection occurs commonly in intensive care units (ICUs). Although critical illness is associated with immune activation, the prevalence of nosocomial infections suggests concomitant immune suppression. This study examined the temporal occurrence of immune dysfunction across three immune cell types, and their relationship with the development of nosocomial infection. METHODS: A prospective observational cohort study was undertaken in a teaching hospital general ICU. Critically ill patients were recruited and underwent serial examination of immune status, namely percentage regulatory T-cells (Tregs), monocyte deactivation (by expression) and neutrophil dysfunction (by CD88 expression). The occurrence of nosocomial infection was determined using pre-defined, objective criteria. RESULTS: Ninety-six patients were recruited, of whom 95 had data available for analysis. Relative to healthy controls, percentage Tregs were elevated 6-10 days after admission, while monocyte HLA-DR and neutrophil CD88 showed broader depression across time points measured. Thirty-three patients (35%) developed nosocomial infection, and patients developing nosocomial infection showed significantly greater immune dysfunction by the measures used. Tregs and neutrophil dysfunction remained significantly predictive of infection in a Cox hazards model correcting for time effects and clinical confounders {hazard ratio (HR) 2.4 [95% confidence interval (CI) 1.1-5.4] and 6.9 (95% CI 1.6-30), respectively, P=0.001}. Cumulative immune dysfunction resulted in a progressive risk of infection, rising from no cases in patients with no dysfunction to 75% of patients with dysfunction of all three cell types (P=0.0004). CONCLUSIONS: Dysfunctions of T-cells, monocytes, and neutrophils predict acquisition of nosocomial infection, and combine additively to stratify risk of nosocomial infection in the critically ill.

Does nausea and vomiting of pregnancy play a role in the association found between maternal caffeine intake and fetal growth restriction?

The aim of this study was to explore the relationships between nausea and vomiting in pregnancy and (a) fetal growth restriction; and (b) maternal caffeine metabolism and fetal growth restriction. A cohort of 2,643 pregnant women, aged 18-45 years, attending two UK maternity units between 8 and 12 weeks gestation, was recruited. A validated tool assessed caffeine intake at different stages of pregnancy and caffeine metabolism was assessed from a caffeine challenge test. Experience of nausea and vomiting of pregnancy was self-reported for each trimester. Adjustment was made for confounders, including salivary cotinine as a biomarker of current smoking status. There were no significant associations between fetal growth restriction and nausea and vomiting in pregnancy, even after adjustment for smoking and alcohol intake. There were no significant differences in the relationship between caffeine intake and fetal growth restriction between those experiencing symptoms of nausea and vomiting and those who did not, for either the first (p = 0.50) or second trimester (p = 0.61) after adjustment for smoking, alcohol intake and caffeine half-life. There were also no significant differences in the relationship between caffeine half-life and fetal growth restriction between those experiencing symptoms of nausea and vomiting and those who did not, for either the first trimester (p = 0.91) or the second trimester (p = 0.45) after adjusting for smoking, alcohol intake and caffeine intake. The results from this study show no evidence that the relationship between maternal caffeine intake and fetal growth restriction is modified by nausea and vomiting in pregnancy.

Esophageal temperature after out-of-hospital cardiac arrest: an observational study.

INTRODUCTION: Out-of-hospital cardiac arrest (OHCA) is a significant cause of death and severe neurological disability. The only post-return of spontaneous circulation (ROSC) therapy shown to increase survival is mild therapeutic hypothermia (MTH). The relationship between esophageal temperature post OHCA and outcome is still poorly defined. METHODS: Prospective observational study of all OHCA patients admitted to a single centre for a 14-month period (1/08/2008 to 31/09/2009). Esophageal temperature was measured in the Emergency Department and Intensive Care Unit (ICU). Selected patients had pre-hospital temperature monitoring. Time taken to reach target temperature after ROSC was recorded, together with time to admission to the Emergency Department and ICU. RESULTS: 164 OHCA patients were included in the study. 105 (64.0%) were pronounced dead in the Emergency Department. 59 (36.0%) were admitted to ICU for cooling; 40 (24.4%) died in ICU and 19 (11.6%) survived to hospital discharge. Patients who achieved ROSC and had esophageal temperature measured pre-hospital (n=29) had a mean pre-hospital temperature of 33.9 degrees C (95% CI 33.2-34.5). All patients arriving in the ED post OHCA had a relatively low esophageal temperature (34.3 degrees C, 95% CI 34.1-34.6). Patients surviving to hospital discharge were warmer on admission to ICU than patients who died in hospital (35.7 degrees C vs 34.3 degrees C, p<0.05). Patients surviving to hospital discharge also took longer to reach T(targ) than non-survivors (2h 48min vs 1h 32min, p<0.05). CONCLUSIONS: Following OHCA all patients have esophageal temperatures below normal in the pre-hospital phase and on arrival in the Emergency Department. Patients who achieve ROSC following OHCA and survive to hospital discharge are warmer on arrival in ICU and take longer to reach target MTH temperatures compared to patients who die in hospital. The mechanisms of action underlying esophageal temperature and survival from OHCA remain unclear and further research is warranted to clarify this relationship.

Rapid sequence induction in the emergency department: induction drug and outcome of patients admitted to the intensive care unit.

OBJECTIVES: Etomidate is used widely for rapid sequence induction (RSI) of anaesthesia in the emergency department (ED) as a result of its relative cardiovascular stability. There is concern over possible adrenal suppression and also that outcomes could be worse than in patients given other induction drugs. This possible association has not been studied in ED patients undergoing RSI. METHODS: 525 consecutive patients who underwent RSI in the ED and were subsequently admitted to an intensive care unit (ICU) were reviewed. The following information was retrieved from the records: induction drug use; incidence of hypotension and vasopressor administration at induction; acute physiology and chronic health evaluation (APACHE) II severity of illness and predicted mortality; and ICU and hospital outcome. The choice of induction drug was not controlled but was at the discretion of the attending clinicians. RESULTS: The numbers of patients given an induction drug were 184 etomidate, 306 thiopental and 35 propofol. Patients given etomidate were older and sicker than those given thiopental or propofol. Mortality appeared greater with etomidate but there was no difference when outcome was related to pre-existing risk. Age, APACHE II score and presenting diagnosis were independent predictors of hospital mortality, but etomidate use was not. CONCLUSION: Induction drug was not related to patient outcome in this cohort of patients. The risks of developing hypotension and receiving a vasopressor at induction were greatest with propofol. Emergency physicians should choose an induction drug based on individual patient circumstances, rather than being solely concerned about adrenal suppression.

Therapeutic hypothermia in comatose patients after out-of-hospital cardiac arrest.

Our intensive care unit has been treating comatose patients, following an out-of-hospital cardiac arrest, with therapeutic hypothermia since 2002. In all, 139 out-of-hospital cardiac arrest patients were admitted in the 4-year period 2002-5. Of these, 27% had a favourable outcome (discharged home or to rehabilitation). Forty-one per cent of patients presenting with ventricular fibrillation (VF) and 7% of non-VF patients had a favourable outcome. No patient with an estimated time from collapse to first attempt at cardiopulmonary resuscitation over 12 min survived to hospital discharge. Twenty-two per cent of patients over 70 years were discharged home, suggesting age was not a barrier to surviving out-of-hospital cardiac arrest. The introduction of a therapeutic hypothermia clinical pathway, at the end of 2003 improved the efficiency of cooling. The percentage of patients cooled to below 34 degrees C within 4 h increased from 15 to 51% and those cooled for more than 12 h increased from 30 to 83%.

Factors affecting the transfer of organochlorine pesticide residues to breastmilk.

Existing studies monitoring organochlorine pesticide residues in breastmilk were examined to identify whether common factors determine the extent of transfer of these residues. A structured review of the English language literature was conducted. Papers were reviewed and assessed using a structured protocol. A total of 77 papers were initially identified, 46 of which contained conclusions relating to the factors which may affect the transfer of residues into breastmilk. Owing to the diversity of findings, papers were screened further to include only those in which a minimum of background information relating to selection of mothers and to milk sampling procedures were reported. Only eight papers were deemed to contain adequate information. Age, parity/length of previous lactation, fat mobilisation and the time of sampling were identified as the most likely factors to be considered when assessing transfer of organochlorine pesticide residues into breastmilk. This review highlights the difficulties of assessing trends in breastmilk contaminants where comparable sampling procedures are not used.

Population-based pharmacokinetic approach for methadone monitoring of opiate addicts: potential clinical utility.

AIMS: There is evidence that plasma methadone measurements may be of benefit in dosage adjustment during methadone maintenance treatment for opiate dependence. However, to date the kinetics of oral rac-methadone have been poorly characterized. We describe plasma methadone concentration-time data collected from 35 opiate addicts. SUBJECTS: Oral doses of rac-methadone were given to 24 male and 11 female addicts attending a community-based drug treatment centre. MEASUREMENTS: Plasma methadone concentrations were measured by liquid chromatography (HPLC). PROCEDURES: Plasma concentration-time data were collected from patients prescribed oral rac-methadone in order to describe the complex kinetics of the drug incorporating its long elimination half-life. FINDINGS: Auto-induction of methadone metabolism was demonstrated and it was observed that clearance of methadone was significantly lower (p < 0.05) in opiate addicts at the start of treatment (median elimination half-life, 128-hours) than in those who had reached steady-state (median elimination half-life, 48 hours). Our data has provided the basis for a population-based pharmacokinetic (POP-PK) model which is intended for use as a clinical tool in association with plasma measurements in methadone maintenance patients. CONCLUSIONS: Using plasma monitoring in combination with the application of Bayesian forecasting it should be possible to predict trough levels of methadone during daily dosing. The model is able to utilize sparse sampling, and two blood samples are expected to be sufficient to define patient compliance. Random samples during treatment could be used to assess methadone dosing by comparing predicted with observed measurements for each individual. The clinical tool could therefore help to detect incomplete (failure to consume the whole daily dose as prescribed) and poor (due to ingestion of extra illicit methadone) compliance as well as therapeutic failure due to drug-drug interactions. Targeting resources in this way could be a cost-effective tool for supervision of methadone dosing.

Analysis of illicit ecstasy tablets: implications for clinical management in the accident and emergency department.

OBJECTIVE: To examine the composition of illicitly manufactured "ecstasy" tablets sold on the UK drugs market. METHODS: Analysis by gas chromatography of 25 illicit ecstasy tablets handed in under amnesty to Leeds Addiction Unit. RESULTS: Illicitly manufactured ecstasy tablets contain a range of ingredients, of widely differing concentrations, and even tablets with the same brand name have variable concentrations of active ingredients. Concentrations of 3,4-methylenedioxymethamphetamine (MDMA) more popularly known as ecstasy, varied 70-fold between tablets. Nine tablets contained neither MDMA nor related analogues. CONCLUSIONS: These results have implications for emergency workers attending to those who have become casualties of the drug ecstasy. Those claiming to have ingested ecstasy may actually have taken other agents that require different clinical management.

Population pharmacokinetics of methadone in opiate users: characterization of time-dependent changes.

AIMS: Although methadone is widely used to treat opiate dependence, guidelines for its dosage are poorly defined. There is increasing evidence to suggest that a strategy based on plasma drug monitoring may be useful to detect non-compliance. Therefore, we have developed a population-based pharmacokinetic (POP-PK) model that characterises adaptive changes in methadone kinetics. METHODS: Sparse plasma rac-methadone concentrations measured in 35 opiate-users were assessed using the P-Pharm software. The final structural model comprised a biexponential function with first-order input and allowance for time-dependent change in both clearance (CL) and initial volume of distribution (V ). Values of these parameters were allowed to increase or decrease exponentially to an asymptotic value. RESULTS: Increase in individual values of CL and increase or decrease in individual values of V with time was observed in applying the model to the experimental data. CONCLUSIONS: A time-dependent increase in the clearance of methadone is consistent with auto-induction of CYP3A4, the enzyme responsible for much of the metabolism of the drug. The changes in V with time might reflect both up- and down-regulation of alpha1-acid glycoprotein, the major plasma binding site for methadone. By accounting for adaptive kinetic changes, the POP-PK model provides an improved basis for forecasting plasma methadone concentrations to predict and adjust dosage of the drug and to monitor compliance in opiate-users on maintenance treatment.

Urine N-acetyl-beta-D-glucosaminidase--a marker of tubular damage?

BACKGROUND: Although an indicator of renal tubular dysfunction, an increased urinary N-acetyl-beta-D-glucosaminidase (NAG) activity might reflect increased lysosomal activity in renal tubular cells. METHODS: Puromycin aminonucleoside (PAN) was administered to Sprague Dawley rats to induce proteinuria. Total protein, albumin, NAG activity and protein electrophoretic pattern were assessed in daily urine samples for 33 days. The morphological appearance of the kidneys was examined on days three, four, six, eight and thirty three and the NAG isoenzyme patterns on days zero, four, eight and thirty three. RESULTS: Following intravenous PAN urine volume and urine NAG activity increased significantly by day two, but returned to normal by day four. After day four all treated animals exhibited a marked rise in urine albumin, total protein excretion and NAG activity. Electrophoresis showed a generalised increase in middle and high molecular weight urine proteins from day four onwards. Protein droplets first appeared prominent in tubular cells on day four. Peak urine NAG activity and a change in NAG isoenzyme pattern coincided with both the peak proteinuria and the reduction in intracellular protein and NAG droplets (day six onwards). CONCLUSIONS: This animal model demonstrates that an increase in lysosomal turnover and hence urine NAG activity, occurs when increased protein is presented to the tubular cells. Urine NAG activity is thus a measure of altered function in the renal tubules and not simply an indicator of damage.

Aurintricarboxylic acid inhibits apoptosis and supports proliferation in a haemopoietic growth-factor dependent myeloid cell line.

The actions of the nuclease inhibitor aurintricarboxylic acid (ATA) were investigated in the growth-factor dependent murine myeloid cell line NSF-60. NSF-60 cells proliferate in response to interleukin-3 (IL-3) and undergo apoptosis when deprived of exogenous IL-3, as demonstrated by the appearance of characteristic DNA 'ladders' following agarose gel electrophoresis. ATA, at concentrations between 5 and 25 microM, inhibited apoptosis in growth-factor deprived cells as demonstrated by inhibition of DNA fragmentation and increased cell survival. ATA at a concentration of 25 microM supported proliferation of the cell line in the absence of exogenous growth-factor. Both ATA and IL-3 increased protein phosphorylation in this cell line. ATA and IL-3 induced proliferation was inhibited by the kinase inhibitors genistein, staurosporine and H-7. These findings suggest that, in NSF-60, ATA is not acting exclusively as an endonuclease inhibitor and that protein phosphorylation is involved in the mechanism of action of ATA in this cell line.

Information needs of workers.

In Britain, the law places duties on employers and suppliers to provide information to ensure health and safety of employees, so far as is reasonably practicable, and there are regulations for the appointment of employees' safety representatives which employers are required to consult. A recent survey by HSE has shown that suppliers are the most important source of information on substances. However, the flow of information is often obstructed by barriers between the suppliers and the companies, and within organisations. Safety representatives, where they exist, are often better informed than employers, and in companies with safety representatives accident rates are lower. Information from suppliers can be inappropriate for the end use, and the goal-setting approach which has dominated in recent years may not help the non-expert employer. We welcome HSE's move to more specific control guidance for chemicals.

Micro-extraction of chlordiazepoxide and its primary metabolites, desmethylchlordiazepoxide and demoxepam, from plasma and their measurement by liquid chromatography.

We have developed a micro-extraction procedure for the analysis of chlordiazepoxide and its two unique metabolites, demoxepam and desmethylchlordiazepoxide, in plasma, using liquid chromatography. The method is both reliable and sensitive for the quantitation of low plasma concentrations of these three compounds. The extraction procedure allows rapid sample processing, which, together with the small sample volume (100 microL), makes it ideal for routine sample handling. The limit of detection for the three compounds ranged from 0.075 to 0.125 mg/L and recovery of the three different benzodiazepines ranged from 87 to 94%. Within- and between-assay coefficients of variation ranged from 3.1-4.5% and from 4.7 to 7.6%, respectively.

The pharmacokinetics of methadone in healthy subjects and opiate users.

AIMS: There is some evidence that monitoring methadone plasma concentration may be of benefit in dosage adjustment during methadone maintenance therapy for heroin (opiate) dependence. However, the kinetics of oral methadone are incompletely characterized. We attempted to describe the latter using a population approach combining intensive 57 h sampling data from healthy subjects with less intensive sparse 24 h data from opiate users. METHODS: Single oral doses of rac-methadone were given to 13 drug-naive healthy subjects (7 men and 6 women) and 17 opiate users beginning methadone maintenance therapy (13 men and 4 women). Plasma methadone concentrations were measured by h.p.l.c. Kinetic analysis was performed using the P-Pharm software. RESULTS: Comparison of kinetic models incorporating mono- or biexponential disposition functions indicated that the latter best represented the data. The improvement was statistically significant for the data from healthy subjects whether the full 57 h or truncated 24 h profiles were used (P<0.031 and P<0.024, respectively), while it was of borderline significance for the more variable data from opiate users (P=0.057) or for pooled (healthy subjects and opiate users) data (P=0.066). The population mean oral clearance of methadone was 6.9+/-1.5 s.d. l h(-1) (5.3+/-1.2 s.d. l h(-1) using 0-24 h data) in the healthy subjects. The results of separate analyses of the data from opiate users and healthy subjects were in contrast with those obtained from pooled data analysis. The former indicated a significantly lower clearance for opiate users (3.2+/-0.3 s.d. l h(-1), P<0.001); 95% CI for the difference = -3 to -6 l h(-1) and no difference in the population mean values of V/F (212+/-27 s.d. l and 239+/-121 s.d. l, P=0.15), while according to the latter analysis addiction was a covariate for V/F but not for oral clearance. A slower absorption of methadone in opiate users was indicated from the analysis of both pooled and separate data. The median elimination half-life of methadone in healthy subjects was 33-46 h depending on the method used to calculate this parameter. CONCLUSIONS: Estimates of the long terminal elimination half-life of methadone (33-46 h in healthy subjects and, possibly, longer in opiate users) indicated that accurate measurement of this parameter requires a duration of sampling longer than that used in this study. Our analysis also suggested that parameters describing plasma concentrations of methadone after a single oral dose in healthy subjects may not be used for predicting and adjusting dosage in opiate users receiving methadone maintenance therapy unless coupled with feedback concentration monitoring techniques (for example Bayesian forecasting).

Micro-extraction of commonly abused benzodiazepines for urinary screening by liquid chromatography.

We have developed a micro-extraction procedure for the analysis of seven commonly prescribed benzodiazepines (chlordiazepoxide, diazepam, lorazepam, nitrazepam, nordiazepam, oxazepam, and temazepam) in urine using liquid chromatography. The method is reliable and sensitive, uses small volumes (100 microL) of urine and is suitable for the detection and quantification of low concentrations of benzodiazepines. The micro-extraction procedure allowed rapid sample processing, which is important for routine sample handling. The limit of detection for the seven benzodiazepines ranged from 0.10-0.71 mg/L and recovery of the different benzodiazepines was good, ranging from 70-105%. Between- and within-assay coefficients of variation ranged from 6.3% to 13.8%, and 2% to 3.5%, respectively. Chlordiazepoxide chromatographed poorly (between assay coefficient of variation 35.4%, within-assay 7%), and we set the cut-off value for this compound at 5.0 mg/L.

Benzodiazepine misuse by drug addicts.

Using a high-performance liquid chromatography method, we measured seven commonly prescribed benzodiazepines (chlordiazepoxide, nitrazepam, nordiazepam, oxazepam, lorazepam, temazepam and diazepam) in 100 urine samples obtained from patients attending the Leeds Addiction Unit. All of the urines selected for investigation were positive for benzodiazepines using an EMIT (Enzyme Immunoassay) screen. Forty-four of the urines contained a range of benzodiazepines, none of which had been prescribed. Nitrazepam was detected most frequently (61 urine samples), but had not been prescribed to any of the patients in this study. Chlordiazepoxide was detected in 49 urine samples, although it had been prescribed to only five patients. Temazepam was detected in 28 urine samples. Fourteen patients providing 21 urine samples had been prescribed temazepam for treatment. However, temazepam was detected in only 14 of these samples. Multiple benzodiazepine abuse was evident from the high rate of detection of unrelated benzodiazepines.

Non-prescribed drug use during methadone treatment by clinic- and community-based patients.

We investigated the efficacy of methadone maintenance treatment in clinic-based (n = 10) and community-based (n = 10) patients by studying the relationships between dose, plasma concentrations of methadone and non-prescribed drug-use using logistic regression. We found that clinic-based patients had significantly reduced odds of having a urine sample test positive for illicit drugs when compared to community-based patients (OR = 0.20; 95% confidence interval 0.10-0.38: p < 0.001). There was no relationship between either methadone dose or plasma methadone concentration and testing positive for non-prescribed drugs (including cocaine, cannabis, amphetamine, ecstasy, benzodiazepines). We looked specifically at the misuse of opiate drugs. Location was again important and clinic-based patients had significantly reduced odds of having a urine sample test positive for opiate drugs (OR = 0.36, 95% confidence interval 0.18-0.71: p approximately 0.004). Opiate drug use in our patients was also significantly related to plasma methadone concentration, increasing noticeably when the drug concentration < 0.48 nmol/L (p approximately 0.04). We found no relationship between methadone dose and odds of having a positive urine drug test in either clinic- or community-based patients.

Leucocyte interleukin-1-like activity in the common seal (Phoca vitulina) and grey seal (Halichoerus grypus).

Interleukin-1 (IL-1) is an important cytokine with predominantly proinflammatory activities, which have been characterized in many mammals. This study showed the production of IL-1-like bioactivity by cultured seal leucocytes. Increasing concentrations of lipopolysaccharide (LPS) (0-1 micrograms/ml) stimulated an increase in measurable IL-1-like activity in cell culture supernates. This activity increased for the first 24 h after LPS stimulation and the substance responsible had an apparent molecular weight of 17 kDa on gel filtration, similar to that described for other species. Specificity of the bioassay used was confirmed by blocking the bioactivity with an IL-1 receptor antagonist (IL-1 ra).