The Barts Health NHS Trust COVID-19 cohort: characteristics, outcomes and risk scoring of patients in East London

BACKGROUND: Barts Health National Health Service Trust (BHNHST) serves a diverse population of 2.5 million people in London, UK. We undertook a health services assessment of factors used to evaluate the risk of severe acute respiratory coronavirus 2 (SARS-CoV-2) infection.METHODS: Patients with confirmed polymerase chain reaction (PCR) test results admitted between 1 March and 1 August 2020 were included, alongwith clinician-diagnosed suspected cases. Prognostic factors from the 4C Mortality score and 4C Deterioration scores were extracted from electronic health records and logistic regression was used to quantify the strength of association with 28-day mortality and clinical deterioration using national death registry linkage.RESULTS: Of 2783 patients, 1621 had a confirmed diagnosis, of whom 61% were male and 54% were from Black and Minority Ethnic groups; 26% died within 28 days of admission. Mortality was strongly associated with older age. The 4C mortality score had good stratification of risk with a calibration slope of 1.14 (95% CI 1.01-1.27). It may have under-estimated mortality risk in those with a high respiratory rate or requiring oxygen.CONCLUSION: Patients in this diverse patient cohort had similar mortality associated with prognostic factors to the 4C score derivation sample, but survival might be poorer in those with respiratory failure.

Current trends of Hepatitis C virus genotypes and associated risk factors in hemophilia patients in Pakistan

Hemophilia is a rare bleeding disorder that needs plasma or clotting factor concentrate transfusion. Therefore chances of blood-borne pathogens like HCV transmission increase due to high prevalence in healthy donors. This study was aimed to determine the prevalence of HCV genotypes and associated risk factors in hemophilia patients of Khyber Pakhtunkhwa, Pakistan. Blood samples and data were collected from 672 hemophiliacs after proper consent obtained from each patient. Samples were analyzed for anti-HCV, HCV RNA and HCV genotype/s detection. Of the total, 22.32% (150) were anti-HCV positive, of which HCV RNA was detected in 18.45% (124) individuals. HCV genotype 3a was found with significantly higher prevalence (p<0.05) (19.35%) as compared to 2a (16.13%) and 1a (12.90%). HCV-3b and HCV-4 were found each in 3.22% samples. Dual infection of genotypes was found in 22.58% of individuals and 22.58% HCV RNA positive sampels were not typed. A total of 572 (85.12%) subjects had hemophilia A and 100 (14.88%) had hemophilia B. In hemophiliacs A the most dominant genotype was 3a (19.27%) while in hemophilia B, genotype 1a was prevalent (26.67%). Whole blood and plasma transfusion were observed as the main risk factors of HCV. It is concluded that HCV genotype 3a and 2a are prevalent in hemophilia patients of Khyber Pakhtunkhwa Pakistan and the main risk factor observed was an unscreened whole blood transfusion.

Retraction notice to "Synergistic effects of thymoquinone and curcumin on immune response and anti-viral activity against avian influenza virus (H9N2) in turkeys" [Poult. Sci. 95 (2016) 1513-1520]

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). The authors retract the above paper due to: 1) conflict of interest among the authors; and 2) addition of coauthor Dr. Muhammad Younus without his knowledge or permission. The authors apologize for these two grave mistakes.

Estrogen protects the blood-brain barrier from inflammation-induced disruption and increased lymphocyte trafficking

Sex differences have been widely reported in neuroinflammatory disorders, focusing on the contributory role of estrogen. The microvascular endothelium of the brain is a critical component of the blood-brain barrier (BBB) and it is recognized as a major interface for communication between the periphery and the brain. As such, the cerebral capillary endothelium represents an important target for the peripheral estrogen neuroprotective functions, leading us to hypothesize that estrogen can limit BBB breakdown following the onset of peripheral inflammation. Comparison of male and female murine responses to peripheral LPS challenge revealed a short-term inflammation-induced deficit in BBB integrity in males that was not apparent in young females, but was notable in older, reproductively senescent females. Importantly, ovariectomy and hence estrogen loss recapitulated an aged phenotype in young females, which was reversible upon estradiol replacement. Using a well-established model of human cerebrovascular endothelial cells we investigated the effects of estradiol upon key barrier features, namely paracellular permeability, transendothelial electrical resistance, tight junction integrity and lymphocyte transmigration under basal and inflammatory conditions, modeled by treatment with TNFα and IFNγ. In all cases estradiol prevented inflammation-induced defects in barrier function, action mediated in large part through up-regulation of the central coordinator of tight junction integrity, annexin A1. The key role of this protein was then further confirmed in studies of human or murine annexin A1 genetic ablation models. Together, our data provide novel mechanisms for the protective effects of estrogen, and enhance our understanding of the beneficial role it plays in neurovascular/neuroimmune disease.

23-year-old female with dyspnea, hematuria, and seizure progressing to respiratory failure

Takayasu arteritis is a rare chronic inflammatory disease on unknown etiology. We report a 23-year old female who presented with fever, shortness of breath and abdominal pain. Shortly thereafter the patient developed hematuria, hemoptysis and seizure progressing to respiratory failure. She was found to have aortitis and alveolar hemorrhage. We discuss the clinical manifestations and the diagnostic work up of Takayasu arteritis. The patient's response to therapy and a discussion on treatment modalities of the disease are also included in the report.

Prevalence of beta-thalassaemia and sickle cell traits in premarital screening in Al-Qassim, Saudi Arabia

To study the prevalence of beta-thalassaemia and sickle cell traits in the Al-Qassim region, Saudi Arabia. The Ministry of Health of Saudi Arabia launched a countrywide programme in February 2004 to allow all Saudis planning marriage to screen their carrier status for beta-thalassaemia and sickle cell traits. This population survey of mandatory premarital screening for beta-thalassaemia and sickle cell heterozygotes provided an opportunity to estimate the prevalence of these traits in the Al-Qassim region. From February 2004 to October 2006 all individuals attending for premarital screening in that region were screened. For each subject, venous blood was taken to determine complete blood count, red cell indices and hemoglobin electrophoresis. Subjects were considered to have beta-thalassaemia trait if mean corpuscular volume was <79 fl, mean corpuscular haemoglobin <27 pg and haemoglobin A2 level >3.5%; and sickle cell trait if sickle cell haemoglobin amounted to 35 to 45% and sickling test was positive. Totally 38,153 individuals were screened during the study period. The prevalence rates of beta-thalassaemia and sickle cell traits were 0.165% (63/38,153) and 0.252% (96/38,153) respectively. Compared with results of previous studies carried out in this region on the same issue, the prevalence of sickle cell heterozygotes seems to be the same but the frequency of beta-thalassaemia carriers is substantially higher. Screening for carriers both of beta-thalassaemia and sickle cell traits is important to prevent at risk marriages through genetic counseling.

Systematic review on urine albumin testing for early detection of diabetic complications

OBJECTIVES

To determine whether microalbuminuria is an independent prognostic factor for the development of diabetic complications and whether improved glycaemic or blood pressure control has a greater influence on the development of diabetic complications in those with microalbuminuria than in those with normoalbuminuria.

DATA SOURCES

Electronic databases up until January 2002.

REVIEW METHODS

A protocol for peer review by an external expert panel was prepared that included selection criteria for data extraction and required two independent reviewers to undertake article selection and review. Completeness was assessed using hand-searching of major journals. Random effects meta-analysis was used to obtain combined estimates of relative risk (RR). Funnel plots, trim and fill methods and meta-regression were used to assess publication bias and sources of heterogeneity.

RESULTS

In patients with type 1 or type 2 DM and microalbuminuria there is a RR of all-cause mortality of 1.8 [95% confidence interval (CI) 1.5 to 2.1] and 1.9 (95% CI 1.7 to 2.1) respectively. Similar RRs were found for other mortality end-points, with age of cohort being inversely related to the RR in type 2 DM. In patients with type 1 DM, there is evidence that microalbuminuria or raised albumin excretion rate has only weak, if any, independent prognostic significance for the incidence of retinopathy and no evidence that it predicts progression of retinopathy, although strong evidence exists for the independent prognostic significance of microalbuminuria or raised albumin excretion rate for the development of proliferative retinopathy (crude RR of 4.1, 95% CI 1.8 to 9.4). For type 2 DM, there is no evidence of any independent prognostic significance for the incidence of retinopathy and little, if any, prognostic relationship between microalbuminuria and the progression of retinopathy or development of proliferative retinopathy. In patients with type 1 DM and microalbuminuria there is an RR of developing end-stage renal disease (ESRD) of 4.8 (95% CI 3.0 to 7.5) and a higher RR (7.5, 95% CI 5.4 to 10.5) of developing clinical proteinuria, with a significantly greater fall in glomerular filtration rate (GFR) in patients with microalbuminuria. In patients with type 2 DM, similar RRs were observed: 3.6 (95% CI 1.6 to 8.4) for developing ESRD and 7.5 (95% CI 5.2 to 10.9) for developing clinical proteinuria, with a significantly greater decline in GFR in the microalbuminuria group of 1.7 (95% CI 0.1 to 3.2) ml per minute per year compared with those who were normoalbuminuric. In adults with type 1 or type 2 DM and microalbuminuria at baseline, the numbers progressing to clinical proteinuria (19% and 24%, respectively) and those regressing to normoalbuminuria (26% and 18%, respectively) did not differ significantly. In children with type 1 DM, regression (44%) was significantly more frequent than progression (15%). In patients with type 1 or type 2 DM and microalbuminuria, there is scarce evidence as to whether improved glycaemic control has any effect on the incidence of cardiovascular disease (CVD), the incidence or progression of retinopathy, or the development of renal complications. However, among patients not stratified by albuminuria, improved glycaemic control benefits retinal and renal complications and may benefit CVD. In the effects of angiotensin-converting enzyme (ACE) inhibitors on GFR in normotensive microalbuminuric patients with type 1 DM, there was no evidence of a consistent treatment effect. There is strong evidence from 11 trials in normotensive type 1 patients with microalbuminuria of a beneficial effect of ACE inhibitor treatment on the risk of developing clinical proteinuria and on the risk of regression to normoalbuminuria. Patients with type 2 DM and microalbuminuria, whether hypertensive or not, may obtain additional cardiovascular benefit from an ACE inhibitor and there may be a beneficial effect on the development of retinopathy in normotensive patients irrespective of albuminuria. There is limited evidence that treatment of hypertensive microalbuminuric type 2 diabetic patients with blockers of the renin--angiotensin system is associated with preserved GFR, but also evidence of no differences in GFR in comparisons with other antihypertensive agents. The data on GFR in normotensive cohorts are inconclusive. In normotensive type 2 patients with microalbuminuria there is evidence from three trials (all enalapril) of a reduction in risk of developing clinical proteinuria; in hypertensive patients there is evidence from one placebo-controlled trial (irbesartan) of a reduction in this risk. Intensive compared with moderate blood pressure control did not affect the rate of progression of microalbuminuria to clinical proteinuria in the one available study. There is inconclusive evidence from four trials of any difference in the proportions of hypertensive patients progressing from microalbuminuria to clinical proteinuria when ACE inhibitors are compared with other antihypertensive agents, and in one trial regression was two-fold higher with lisinopril than with nifedipine.

CONCLUSIONS

The most pronounced benefits of glycaemic control identified in this review are on retinal and renal complications in both normoalbuminuric and microalbuminuric patients considered together, with little or no evidence of any greater benefit in those with microalbuminuria. Hence, microalbuminuric status may be a false boundary when considering the benefits of glycaemic control. Classification of a person as normoalbuminuric must not serve to suggest that they will derive less benefit from optimal glycaemic control than a person who is microalbuminuric. All hypertensive patients benefit from blood pressure lowering and there is little evidence of additional benefit in those with microalbuminuria. Antihypertensive therapy with an ACE inhibitor in normotensive patients with microalbuminuria is beneficial. Monitoring microalbuminuria does not have a proven role in modulating antihypertensive therapy while the patient remains hypertensive. Recommendations for microalbuminuria research include: determining rate and predictors of development and factors involved in regression; carrying out economic evaluations of different screening strategies; investigating the effects of screening on patients; standardising screening tests to enable use of common reference ranges; evaluating the effects of lipid-lowering therapy; and using to modulate antihypertensive therapy.

Effect of Model Ligands on Iron Redox Speciation in Natural Waters Using Flow Injection with Luminol Chemiluminescence Detection

The effects of dissolved organic compounds on the determination of nanomolar concentrations of Fe(II) have been compared using two luminol-based flow injection chemiluminescence (FI-CL) methods. One used the direct injection of sample into the luminol reagent stream, and the other incorporated on-line solid-phase extraction of the analyte on an 8-hydroxyquinoline microcolumn. The CL signals from analyses of dissolved iron species (Fe(II) and Fe(III)) with model ligands and organic compounds were examined in high-purity water and seawater. The organic compounds included natural reducing agents (e.g., ascorbic acid), nitrogen sigma-donor/pi-acceptor compounds (e.g., 1,4-dipyridine, protoporphyrin IX), aromatic compounds (e.g., 1,4-dihydroxybenzene), synthetic iron chelators (e.g., EDTA), and natural iron binding compounds (e.g., desferrioxamine B, ferrichrome A). Fe(II) determinations for both luminol FI-CL methods were affected by submicromolar concentrations of redox-active compounds, strong iron binding ligands (i.e., log K(FeL) > 6), and compounds with electron-donating functional groups in both high-purity water and seawater. This was due to reactions between organic molecules and iron species before and during analysis, rather than chemiluminescence caused by the individual organic compounds. In addition, the effects of strong ligands and size speciation on Fe(II) recoveries from seawater following acidification (pH 2) and reduction (100 microM sodium sulfite) were investigated.

A survey to determine the blood concentration of cyclosporine 2 hours postdose in stable renal transplant patients

The current method for monitoring cyclosporine measures predose concentrations (C0). A better method has been developed, namely, measurement of the blood cyclosporine concentration at 2 hours postdose (C2). The aim of this survey was to determine the variability of C0 and C2 concentrations among stable renal transplant patients. One hundred two stable renal transplant patients who were at least 6 months posttransplant were recruited from the renal transplant outpatient clinic. The cyclosporine dose was between 100 and 500 mg daily; all patients had been monitored using C0 concentrations. Blood samples for cyclosporine concentration measurements were taken at both C0 and C2 at two consecutive clinic visits. The within- and between-patient variabilities were calculated using nested analysis of variance. The mean age was 50 years (21 to 81); the mean weight was 75 kg. The mean cyclosporine dose was 3.18 mg/kg/d (1.2 to 8.8). The average serum creatinine was 174 micromol/L (77 to 626) and the average cholesterol was 5 micromol/L (3 to 9). The mean (+/-SD) C0 concentration was 150 (47.31) microg/L and C2=895 (239) microg/L. The C0 concentration varied over 16-fold between patients compared to a sevenfold variation in C2. The between-subject coefficient of variation (CV) was 35% for C0 and 30% for C2 and the within subject CV was 23% for C0 and 20% for C2. The results suggest that cyclosporine concentrations at C0 are slightly more variable than those at C2. Whether this modest reduction in variability results in better patient outcomes is the subject of the next phase of this study.

Mild intellectual disability in children in Lahore, Pakistan: aetiology and risk factors

BACKGROUND

One of the main objectives of studying intellectual disability (ID) in children is to explore its causes. A specific aetiological diagnosis is important in determining the prognosis, nature and extent of services needed to support affected children.

METHODS

Aetiology and risk factors in mild ID were studied in a cohort of longitudinally followed children (6-10 years of age, n = 40) in four population groups in and around Lahore, Pakistan.

RESULTS

The overall prevalence of mild ID was 6.2%. In 22% of the cases the onset of mild ID was prenatal with small for gestational age and multifactorial inheritance as the main underlying factors. During the postnatal period (28% of the cases), social deprivation and malnutrition were the major causes of ID. In a substantial proportion of the cases (50%), the cause of ID could not be traced.

CONCLUSION

The present study indicates a clear relationship of mild ID with prenatal and postnatal malnutrition and social deprivation. Two independent variables, maternal illiteracy and small head circumference at birth, showed a clear association with the development of mild mental disability among children in the study population.

Determination of sulphite using an immobilized enzyme withflow injection chemiluminescence detection

A flow injection method is reported for the determination of sulphite-based on chemiluminescent detection. Hydrogen peroxide is produced from sulphite using on-line covalently bound immobilized sulphite oxidase packed in a mini-column, which was mixed downstream and detected via cobalt(II)-catalysed chemiluminescent oxidation of luminol. The limit of detection (2 x standard deviation of the blank) was 1 x 10(-3) mmol/L with sample throughput 60 h(-1). The calibration data was linear over the range of 0.2-1.0 mmol/L with relative standard deviation (n = 4) in the range 0.9-2.0%.

Determination of iron in blood serum using ?ow injection with luminol chemiluminescence detection

A simple and rapid fl ow injection method is reported for the determination of iron in blood serum after acid digestion with HNO3 and HClO4, based on luminol CL detection in the absence of added oxidant. The detection limit (3 s) was 1.0 nmol/L with a sample throughput of 120/h. The calibration graph was linear over the range 0.001-1.0 micromol/L (r2 = 0.9974), with relative standard deviations (RSD) (n = 4) in the range 3.2-5%. The effect of interfering cations (Ca(II), Mg(II), Cu(II), Cd(II), Pb(II), Mn(II), Zn(II), Ni(II), Co(II) and Fe(III)) and anions (Cl-, SO4(2-), HCO3-, NO3-, NO2-) were studied using a luminol CL system for Fe(II) determination. The method was applied to normal blood serum and the results (1.32 +/- 0.08-1.74 +/- 0.05 mg/L) were compared with those from a spectrophotometric reference method (1.34 +/- 0.06-1.80 +/- 0.10 mg/L), which agree fairly well with the overall reference range in blood.

Flow injection chemiluminescent assays for glycerol and triglycerides using a co-immobilized enzyme reactor

A flow injection method for the determination of glycerol using a co-immobilized enzyme reactor containing glycerokinase and glycerol-3-phosphate oxidase is described. The hydrogen peroxide produced is monitored by using a luminol chemiluminescence reaction in the presence of catalyst such as Co(II). The detection limit (2.5 x blank noise) for glycerol is 7 x 10(-3) mmol/L with a sample throughput of 40/h. The calibration graph is linear over the range studied (0.2-1.0 mmol/L) with relative standard deviation 1.2-2.4%. The method is applied to the determination of glycerol in blood serum produced off-line from triglycerides using lipase isolated from bovine pancreas.

Prevalence and associated impairments of mild mental retardation in six- to ten-year old children in Pakistan: a prospective study

The aim of this study was to find the prevalence of mild mental retardation (MMR) in 6-10-y-old children in a prospectively followed cohort in Pakistan from four areas with different socioeconomic conditions. Retarded children were identified by a two-step method, comprising a household screening with the Ten Questions Screening in 649 families followed by clinical investigation and psychometric testing (WISC-R and Griffiths) of the 132 children found by the screening. The overall prevalence of MMR among 6-10-y-old children was 6.2%. The distribution of MMR was uneven, with 1.2% among children from the upper-middle class, 4.8% in the village, 6.1% in the urban slum and 10.5% in the poor periurban slum area. Additional impairments were found in 75% of the children with MMR, of which speech impairment was the most common.

CONCLUSION

The prevalence of MMR was found to be higher in a developing country than in developed countries. It also seemed to be related to poor socioeconomic conditions, as the prevalence in the upper-middle class was comparable to figures from developed countries, while the prevalence in children from poor population groups was much higher.

Cardiovascular disease determinants in chronic renal failure: clinical approach and treatment

INTRODUCTION

Cardiovascular disease (CVD), as the leading cause of morbidity and mortality in patients on renal replacement therapy (RRT), has a central role in everyday nephrological practice.

METHODS

Consensus was reached on key points relating to the clinical approach and treatment of the main cardiovascular risk factors in RRT patients (hypertension, anaemia, hyperparathyroidism, dyslipidaemia, new emerging risk factors). In addition, the role of convective treatments on cardiovascular outcomes was examined.

RESULTS

Hypertension should be managed by aiming at blood pressure values of < or =140/90 mmHg (< or =160/90 mmHg in the elderly), firstly by ensuring target dry body weight is achieved. No single class of drug has proved superior to others in RRT patients, provided that the blood pressure target is achieved, although ACE inhibitors have shown specific organ protection in high-risk patients (HOPE study) and are well tolerated. Anaemia should be managed by using erythropoietin and iron supplements, aiming at haemoglobin levels of 12 g/dl and keeping serum ferritin levels < 500 ng/ml. The management of hyperparathyroidism is currently unsatisfactory, as calcium supplements have the potential to increase cardiovascular calcification. While awaiting new calcium- and aluminium-free phosphate binders, it is essential to ensure dialysis adequacy. Clinical studies are in progress to assess the real impact of lipid-lowering drugs in RRT. In the meantime, serum LDL-cholesterol < 160 mg/dl and triglycerides < 500 mg/dl may be desirable targets. The impact of new emerging risk factors (inflammation and chronic infection, hyperhomocysteinaemia, metabolic waste-product accumulation) and their proper management are still under research. Convective dialysis treatments may confer some degree of protection from dialysis-related amyloidosis and mortality, but clinical data on this important issue are still controversial and no definitive conclusions can be drawn at present.

CONCLUSION

CVD prevention and treatment is a great challenge for the nephrologist. Achieving evidence-based consensus can help in encouraging the implementation of best clinical practice in line with the progress of current knowledge.

CMV viral load measurements in whole blood and plasma--which is best following renal transplantation?

BACKGROUND

Quantitative commercial assays for cytomegalovirus (CMV) detection have recently been developed. Their role in the management of patients after transplantation needs to be evaluated. Widespread use of these assays will allow for comparison of results between centers and meaningful interpretation of the significance of viral load measurements.

METHODS

Sequential samples from 52 patients after renal transplantation were tested in the murex hybrid capture assay (HCA) and the Roche Amplicor CMV DNA assay (QPCR) and correlated with the development of CMV disease. A comparison of viral loads in plasma and whole blood was also made.

RESULTS

Both assays were sensitive and detected all cases of CMV disease. The specificity and positive predictive value increased from 0.34 and 0.36 to 0.85 and 0.96 for the HCA and 0.37, 0.37 to 0.72 and 0.63 for the QPCR following a receiver operator curve analysis. Higher viral loads were measured using the HCA compared to the QPCR. Response to ganciclovir was associated with a greater than 80% reduction in viral load by HCA or greater than 70% using the QPCR.

CONCLUSIONS

Both assays were highly sensitive. By using a receiver operator curve analysis a cutoff viral load can be determined which maximizes the clinical utility of these assays.

Regulation of bradykinin receptor gene expression in human lung fibroblasts

In WI-38 human fibroblasts, interleukin-1 beta and tumour necrosis factor-alpha (TNF-alpha) increased bradykinin B(1) receptor mRNA, which peaked between 2 and 4 h, remaining elevated for 20 h. Binding of the bradykinin B(1) receptor selective ligand [3H]des-Arg(10)-kallidin, also increased, peaking at 4 h and remaining elevated for 20 h. The B(max) value for [3H]des-Arg(10)-kallidin rose from 280+/-102 fmol/mg (n=3) to 701+/-147 fmol/mg (n=3), but the K(D) value remained unaltered (control, 1.04+/-0.33 nM (n=3); interleukin-1 beta, 0.88+/-0.41 nM (n=3)). The interleukin-1 beta-induced [3H]des-Arg(10)-kallidin binding sites were functional receptors, as bradykinin B(1) receptor agonist-induced responses increased in treated cells. Bradykinin B(2) receptor mRNA and [3H]bradykinin binding were upregulated by interleukin-1 beta, but not TNF-alpha. The effect of interleukin-1 beta on bradykinin B(2) receptors was smaller than for bradykinin B(1) receptors. Cycloheximide prevented interleukin-1 beta-mediated increases in B(1) and B(2) binding, but not mRNA suggesting that de novo synthesis of a transcriptional activator was unnecessary.

Simultaneous treatment of cytomegalovirus and varicella zoster infections in a renal transplant recipient with ganciclovir: use of viral load to monitor response to treatment

Disseminated zoster occurring simultaneously with cytomegalovirus (CMV) disease in a renal transplant recipient is potentially life threatening. We describe the use of intravenous ganciclovir to treat both infections. The efficacy of treatment was assessed clinically and by the measurement of CMV viral load using the hybrid capture (Murex version 2) and varicella zoster (VZV) viral load using an in-house assay. Results from this case suggest that clinical resolution in severe viral infections such as described below may be related to early control of viraemia.

Identification of system y+L as the high-affinity transporter for L-arginine in human platelets: up-regulation of L-arginine influx in uraemia

Kinetic studies of L-arginine transport in human platelets have identified a high-affinity, low-capacity transport system [Michaelis-Menten constant (K(m)) about 10 microM] for cationic amino acids that also transports neutral amino acids with high affinity in the presence of Na+ but not K+. These characteristics, together with our kinetic cis-inhibition studies, indicate that saturable L-arginine transport in human platelets is mediated via the system y+L and not the classic cationic transporter system y+. We present here the first evidence that L-arginine transport via system y+L is increased twofold in platelets from patients with chronic renal failure. System y+L has been described in human erythrocytes, peripheral blood mononuclear cells and placenta, and up-regulation of system y+L activity in human platelets could explain the paradox of increased nitric oxide (NO) production by uraemic platelets under conditions of decreased plasma L-arginine and elevated NG-monomethyl-L-arginine (L-NMMA) concentrations.

Use of molecular assays in diagnosis and monitoring of cytomegalovirus disease following renal transplantation

We compared two commercial molecular assays (the Murex Hybrid Capture CMV DNA assay [HCA], version 2, and the Roche Amplicor plasma PCR assay) with a standard shell vial assay in detecting and predicting cytomegalovirus (CMV) disease in a group of renal transplant patients and assessed the role of viral load measurements (using the HCA) in their management. The sensitivity of the HCA and Amplicor assay in terms of disease detection was 100%, compared to 71% for the shell vial assay. Both the HCA and the PCR assay detected all cases of disease, at medians of 11 and 12.5 days before the onset of symptoms, respectively. Significantly higher viral loads were detected in those patients with symptoms (7.9 x 10(5) copies/ml) than in patients without symptoms (7.9 x 10(4) copies/ml; P < 0.0001). There was also a trend towards higher viral loads in those patients with primary infections (7.8 x 10(5) copies/ml) than in those patients with reactivations of CMV disease or reinfections. Successful treatment with ganciclovir was associated with a >90% reduction in viral load. Both of these new assays are sensitive and easy to use. A comparison of accurate quantitation is also useful in monitoring responses to antiviral therapy.

Molecular characterisation of cloned bradykinin B1 receptors from rat and human

This report describes the characterisation of cloned rat and human bradykinin B1 receptors in African green monkey kidney fibroblast (Cos-7) cells. A ligand binding assay with [3H]des-Arg10-kallidin was used to compare their pharmacology with respect to known bradykinin B1 and B2 receptor ligands. In addition, the pharmacology of T-kinin and its' derivative des-Arg11-T-kinin was investigated. The cloned rat receptor had a similar pharmacology to that of the recently described mouse receptor and differs from that described for the human receptor. The rat receptor had a higher affinity for des-Arg11-T-kinin than the human receptor. These differences in pharmacological properties may relate to the presence of T-kinin, bradykinin and their des-Arg derivatives as the major physiological peptides in rat and the predominance of kallidin and its derivatives in human. We confirm that the rat bradykinin B1 receptor gene is organised in a two exon structure and differs from the human gene which has a three exon structure and we further examine the inducible expression of this gene in a wide range of tissues using Northern blotting.

Linkage analysis excludes familial congenital hypothyroidism from chromosome 21

Congenital hypothyroidism (CH) is a heterogeneous disorder with largely unknown causes, affecting 1/3000-1/4000 new-borns. Individuals with Down syndrome have a much higher incidence of CH than the normal population, probably due to the extra copy of chromosome 21. Moreover, a girl has recently been described with CH and an interstitial deletion of proximal 21q, possibly revealing a recessive disease allele on the undeleted chromosome. To establish whether chromosome 21 is also involved in the etiology of familial cases of presumably autosomal recessive CH, we investigated 22 families with recessive CH, using 10 microsatellite markers from 21q. Linkage analysis allowing for heterogeneity revealed no signs of linkage even in a small proportion of the families, and two-point analysis of the markers made it possible to exclude the long arm of chromosome 21 from containing any major disease-causing gene.

Risk factors for mortality in young children living under various socio-economic conditions in Lahore, Pakistan: with particular reference to inbreeding

Risk factors such as maternal age, parity, previous siblings' death, inbreeding of parents, birth weight, birth length were examined in a population-based prospective study in four population groups at different levels of urbanization in and round Lahore, Pakistan. From September 1984 to March 1995, 2967 full-term, single born infants were followed from the 5th month of gestation to 12 months of age. Logistic regression analysis showed a significant relative risk (RR) of infant death associated with parents' consanguinity (RR = 1.8), birth weight (RR = 1.8) and elder siblings' death (RR = 1.7). The risk attributed to these factors was 28, 17 and 25%, respectively. The number of lethal equivalents per gamete is about one. The B/A ratio 10.36 suggests that the genetic load is likely to be mutational. In countries like Pakistan, where consanguinity is favourably practiced, a substantial proportion of infant deaths may be prevented by cessation of such marriages. The implications of this finding for the Pakistani community are discussed.

Fungal transformation of (1R,2S,5R)-(-)-menthol by cephalosporiumaphidicola

Incubation of (1R,2S,5R)-(-)-menthol (1) with Cephalosporium aphidicola for 12 days yielded the six oxidized metabolites: 10-acetoxymenthol (2), 7-hydroxymenthol (3), 4alpha-hydroxymenthol (4), 3alpha-hydroxymenthol (5), 9-hydroxymenthol (6), and 10-hydroxymenthol (7). The structures of the novel compounds 2, 4, 5, and 7 were assigned by interpretation of their spectral data.

Serum hyaluronan levels follow disease activity in vasculitis

Hyaluronan (HA) is a high molecular weight polysaccharide present in the extracellular matrix of most tissues. It is a major component of loose connective tissues such as skin, synovial fluid and the vitreous body, and during embryonic development, tissue repair, tumor growth and at inflammatory sites. Increased serum concentrations have been reported in association with tissue damage, certain inflammatory diseases, notably rheumatoid arthritis and scleroderma, liver malfunction and in some malignancies. Currently there are no serological markers available that monitor the extent of tissue damage in vasculitis. We therefore, conducted this study to investigate the significance of serum HA in patient with systemic vasculitis (SV). Ten patients with SV and acute renal failure had elevated HA levels compared to normal age and gender matched controls (n = 31) (mean +/- SD: 673.8 +/- 495.14 micrograms/l and 90.26 +/- 37.18 micrograms/l, respectively; p < 0.001]. Eight of these patients were studied longitudinally for ten days, after pulse steroids, during which serum HA levels fell paralleling clinical improvement, despite the persistence of positive perinuclear-anti-neutrophil cytoplasmic antibody (p-ANCA) serology in three patients. In two patients, the clinical course was complicated by sepsis which was accompanied by an acute rise in serum HA. One patient suffered a relapse of vasculitis, with lung hemorrhage and a sudden rise in HA (> 2,000 micrograms/l), but c-ANCA serology remained normal. Serum HA was also measured in a further ten patients in clinical remission from SV and found to be within the normal range (82.44 +/- 39.06 micrograms/l). One patient, with equivocal clinical relapse after transplantation, exhibited high p-ANCA (404 IU) but serum HA remained normal (ten readings over six months 0-163 micrograms/l). Little change was seen in symptoms, or HA and ANCA serology, following plasma exchange. These preliminary data indicate that serum HA is raised in active vasculitis and may be a useful adjunctive marker of disease activity and extent of tissue damage.

Chemiluminescent assays for choline and phospholipase-D using a flow injection system

A flow injection chemiluminescent method is described for the determination of choline. The method is based on the production of hydrogen peroxide from choline using on-line covalently bound immobilized choline oxidase column. The product is mixed downstream and detected via the cobalt catalyzed chemiluminescent oxidation of luminol. The detection limit is 1 x 10(-7) mol/L, with rsd 1.8 to 2.8% in the range 2-10 x 10(-5) mol/L. The sample throughput is 30 per hour. The method was applied to the determination of choline produced off-line from phosphatidylcholine using phospholipase-D isolated from cabbage.

Genetic and linkage analysis of familial congenital hypothyroidism: exclusion of linkage to the TSH receptor gene

Congenital hypothyroidism affects 1/3000-4000 newborns. The causes of this group of disorders are still largely unknown. Although most cases are sporadic some families have several affected children and/or consanguineous parents, suggesting autosomal recessive inheritance. Furthermore, there is a murine strain (hyt) with congenital hypothyroidism and autosomal recessive inheritance, whose phenotype appears to be identical with the corresponding human disease. In the hyt mouse, the disease is caused by a mutation in the thyroid-stimulating hormone receptor (TSHR) gene, making this gene a likely candidate also for the human disease. The human TSHR gene was mapped on radiation hybrid panels and closely linked flanking markers D14S287 and D14S616 were identified. On the Genebridge 4 panel, D14S287 was found to be located 8.5 cR (corresponding to 2.3 cM) proximal to the TSHR gene, and D14S616 was found to be located 4.4 cR (1.2 cM) distal to the TSHR gene. These markers were analyzed in 23 families, most of them with two or more children affected by congenital hypothyroidism and some with appreciable consanguinity of the parents. Assuming homogeneity, the two-point lod score at theta = 0.1 was -4.8 for D14S287 and -5.8 for D14S616, and thus linkage to the TSHR gene was excluded. Even when the data were analyzed with allowance for heterogeneity, there was no evidence of linkage. Our conclusion is that if mutation of the TSHR gene causes familial congenital hypothyroidism in humans, it affects only a small proportion of the cases.

Antibodies to collagen IV in the serum of workers exposed to hydrocarbons and volatile organic chemicals

Significant numbers of workers (14%) chronically exposed to volatile organic chemicals commonly found in spray paints had elevated levels of uncharacterized antibodies to collagen IV, a basement membrane protein. No increased frequency of subjects with positive results for anti-glomerular basement membrane antibodies (anti-GBM) was found in this group. These anti-GBM antibodies are directed against a specific epitope on the non-collagenous domain (NC1) of the α3 chain of collagen IV. Anti-GBM antibodies are diagnostic for Goodpasture's syndrome that has been reported to occur following acute inhalation of volatile substances. In another group of workers, exposed both dermally and by inhalation to petroleum-based oil mists, 5% had positive results for antiGBM antibodies. We conclude that the measurement of general, uncharacterized antibodies to collagen IV may be a useful indicator of basement membrane damage in workers occupationally exposed to volatile organic chemicals.

Flow-injection chemiluminescent determination of glycerol-3-phosphate and glycerophosphorylcholine using immobilized enzymes

Flow injection procedures with immobilized enzyme mini-columns are described for the determination of glycerol-3-phosphate, and glycerophosphorylcholine with chemiluminescent detection. The hydrogen peroxide produced on-line is coupled with a luminol (5-amino-2,3,-dihydro-1,4-phthalazinedione) peroxidation chemiluminescent system. The detection limits for glycerol-3-phosphate and glycerophosphorylcholine are 5 x 10(-7) M and 1 x 10(-6) M respectively with r.s.d. < 2%. The sample throughput is 40/h. The immobilized enzyme columns did not show any deterioration in activity after usage for 3 months.

5-amino salicylic acid absorption and metabolism in ulcerative colitis patients receiving maintenance sulphasalazine, olsalazine or mesalazine

BACKGROUND

All 5-aminosalicylic acid (5-ASA) preparations are potentially nephrotoxic, but there has been concern that newer delivery systems may increase this risk, either because of altered absorption or altered metabolism. Previous studies of 5-ASA absorption and excretion have usually either been performed in healthy controls or have only examined short-term therapy. 5-ASA and N-acetyl-5-ASA have therefore been measured in blood samples, and N-acetyl-5-ASA in urine samples, from patients with ulcerative colitis on long-term maintenance with different 5-ASA preparations and compared with sensitive markers of renal damage.

METHODS

Patients receiving mesalazine (Asacol) (n = 13), sulphasalazine (n = 12) or olsalazine (Dipentum) (n = 8), all at doses within the recommended range were studied. Six-hour and trough serum concentrations of 5-ASA and N-acetyl-5-ASA and 24-h urinary excretion of N-acetyl-5-ASA were measured by high-performance liquid chromatography.

RESULTS

Absorption of 5-ASA, assessed as 24-h excretion of N-acetyl-5-ASA expressed as molar % of ingested dose, was greater in patients receiving mesalazine, 23.25 +/- 10.65% (mean +/- s.d.; n = 13), than those receiving sulphasalazine (11.16 +/- 10.52%, n = 12; P = 0.003) or olsalazine (9.70 +/- 3.89%, n = 8; P < 0.002). The ratio of 5-ASA: N-acetyl-5-ASA in the serum 6 h after dose was also greater with mesalazine (1.02 +/- 0.44, mean +/- s.d.) than sulphasalazine (0.54 +/- 0.44, P < 0.02) or olsalazine (0.38 +/- 0.44, P < 0.005). Urinary markers of tubular damage were increased in four of 33 patients, but showed no correlation with concentration of 5-ASA or N-acetyl-5-ASA in serum and N-acetyl-5-ASA in urine, nor with lifetime dose or average daily dose of 5-ASA.

CONCLUSIONS

In patients with ulcerative colitis receiving maintenance 5-ASA therapy there was greater absorption and less acetylation of 5-ASA from mesalazine (Asacol) compared with sulphasalazine or olsalazine, but no evidence from this study that this resulted in increased nephrotoxicity.

Selective labelling of bradykinin receptor subtypes in WI38 human lung fibroblasts

1. Binding of the B1 bradykinin receptor radioligand, [3H]-des-Arg10-kallidin (-KD) and the B2 receptor radioligand [3H]-bradykinin (-BK) was investigated in membranes prepared from WI38 human foetal lung fibroblasts. 2. One-site analysis of the saturation data for [3H]-des-Arg10-KD gave an equilibrium dissociation constant (KD) value of 0.51 +/- 0.12 nM and a maximum receptor density (Bmax) of 260 +/- 49 fmol mg-1 of protein. [3H]-des-Arg10-KD binding was displaced by ligands in the order: des-Arg10-KD > KD > > des-Arg9[Leu8]-BK > des-Arg9-BK > Hoe 140 > > BK, implying that it was binding selectively to B1 receptors. 3. One-site analysis of the binding of [3H]-BK to W138 membranes indicated that it had a KD value of 0.25 +/- 0.06 nM and a Bmax of 753 +/- 98 fmol mg-1 of protein. The potencies for displacement of [3H]-BK binding were: Hoe 140 > > BK = KD > > > des-Arg10-KD = des-Arg9[Leu8]-BK = des-Arg9-BK, which was consistent with binding to B2 receptors. 4. This is the first characterization of [3H]-des-Arg10-KD binding to include both kinetic and equilibrium data, and demonstrates that [3H]-des-Arg10-KD has a high affinity for human B1 bradykinin receptors and is sufficiently selective to be used as a radioligand for B1 receptors in human cells or tissues expressing an excess of B2 BK receptors.