Measurement of serum 7α-hydroxy-4-cholesten-3-one as a marker of bile acid malabsorption in dogs with chronic diarrhoea: a pilot study.

Bile acid malabsorption is a common cause of chronic diarrhoea in people, however it has never previously been investigated in dogs, despite clinical suspicion of its existence. The goal of this study was to assess the feasibility of measuring serum 7α-hydroxy-4-cholesten-3-one (C4) in dogs, as a potential marker of bile acid malabsorption, and to see whether this is related to clinical disease severity or the presence of hypocobalaminaemia. Serum C4 concentration was measured in 20 clinically healthy control dogs and 17 dogs with chronic diarrhoea. Three of the 17 affected dogs (17.6 per cent) had a C4 concentration significantly above the range of clinically healthy dogs; these dogs were all poorly responsive to conventional therapy. These results suggest that bile acid malabsorption may be a clinically relevant disorder in dogs with chronic diarrhoea and serum C4 may be a useful tool to investigate this further.

Inflammatory and bone turnover markers in a cross-sectional and prospective study of acute Charcot osteoarthropathy.

AIMS: To assess markers of inflammation and bone turnover at presentation and at resolution of Charcot osteoarthropathy. METHODS: We measured serum inflammatory and bone turnover markers in a cross-sectional study of 35 people with Charcot osteoarthropathy, together with 34 people with diabetes and 12 people without diabetes. In addition, a prospective study of the subjects with Charcot osteoarthropathy was conducted until clinical resolution. RESULTS: At presentation, C-reactive protein (P = 0.007), tumour necrosis factor-α (P = 0.010) and interleukin-6 (P = 0.002), but not interleukin-1ß, (P = 0.254) were significantly higher in people with Charcot osteoarthropathy than in people with and without diabetes. Serum C-terminal telopeptide (P = 0.004), bone alkaline phosphatase (P = 0.006) and osteoprotegerin (P < 0.001), but not tartrate-resistant acid phosphatase (P = 0.126) and soluble receptor activator of nuclear factor-κß ligand (P = 0.915), were significantly higher in people with Charcot osteoarthropathy than in people with and without diabetes. At follow-up it was found that tumour necrosis factor-α (P = 0.012) and interleukin-6 (P = 0.003), but not C-reactive protein (P = 0.101), interleukin-1ß (P = 0.457), C-terminal telopeptide (P = 0.743), bone alkaline phosphatase (P = 0.193), tartrate-resistant acid phosphatase (P = 0.856), osteoprotegerin (P = 0.372) or soluble receptor activator of nuclear factor-kß ligand (P = 0.889), had significantly decreased between presentation and the 3 months of casting therapy time point, and all analytes remained unchanged from 3 months of casting therapy until resolution. In people with Charcot osteoarthropathy, there was a positive correlation between interleukin-6 and C-terminal telopeptide (P = 0.028) and tumour necrosis factor-α and C-terminal telopeptide (P = 0.013) only at presentation. CONCLUSIONS: At the onset of acute Charcot foot, serum concentrations of tumour necrosis factor-α and interleukin-6 were elevated; however, there was a significant reduction in these markers at resolution and these markers may be useful in the assessment of disease activity.

Importance of cannulated prolactin test in the definition of hyperprolactinaemia.

PURPOSE: Recent guidelines suggest that a single prolactin measurement is adequate to confirm hyperprolactinaemia. This may lead to unnecessary investigation of artefactual hyperprolactinaemia. Prolactin measurement drawn from an indwelling cannula after rest removes stress as a confounding variable. The objective was to determine the frequency of true hyperprolactinaemia amongst patients referred following a single prolactin measurement. METHODS: A cannulated study was considered if prolactin on referral ('Referral Prolactin') was <5,500 mU/L (260 ng/mL) but >410 mU/L (19 ng/mL) in males or >510 mU/L (24 ng/mL) in females, irrespective of clinical context. Case-notes of 267 patients undergoing cannulated prolactin measurement over a 10-year period (2000-2010) were reviewed. Pre-existing pituitary disease, dopamine antagonist use, and macroprolactinaemia were excluded. Morning ante-cubital vein cannulation was followed immediately by withdrawal of 'Repeat Prolactin' sample. After 120-min bed-rest, 'Resting Prolactin' was withdrawn through the cannula. RESULTS: 235 patients were included for analysis. 64 (27%) were within normal range; following Repeat Prolactin in 41 (17%) and Resting Prolactin in 23 (9%) cases. Referral Prolactin was higher in patients with true hyperprolactinaemia, 1,637 ± 100 mU/L (77.2 ± 4.7 ng/mL) than with artefactual hyperprolactinaemia, 1,122 ± 68 mU/L (52.9 ± 3.2 ng/mL; P < 0.001) but there was substantial overlap. 21 out of 171 cases (12%) with true hyperprolactinaemia had a macroadenoma. Presenting symptoms did not predict true hyperprolactinaemia. Referral Prolactin of 2,000 mU/L (94 ng/mL) had 97% specificity to identify true hyperprolactinaemia. CONCLUSIONS: Reliance on a single, non-rested prolactin value may lead to over-diagnosis of hyperprolactinaemia. A resting sample should be considered with random values <2,000 mU/L (94 ng/mL).

Randomised clinical trial: A liquid multi-strain probiotic vs. placebo in the irritable bowel syndrome--a 12 week double-blind study.

BACKGROUND: The importance of interactions between the host and gut microbiota in the pathogenesis of irritable bowel syndrome (IBS) is becoming increasingly apparent. Probiotics offer a potential new treatment for IBS, but current results are conflicting, largely as a result of poorly designed trials and nonstandardisation of outcome measures. AIM: To assess the efficacy of a liquid, multi-strain probiotic (Symprove) in IBS. METHODS: A single-centre, randomised, double-blind, placebo-controlled trial of adult patients with symptomatic IBS. Patients received 12 weeks of treatment with the probiotic or placebo (1 mL/kg/day). The primary efficacy measure was the difference in change in the IBS symptom severity score (IBS-SSS) between probiotic vs. placebo at week 12. Secondary outcome measures included change in the IBS quality of life (IBS-QOL) score and change in the IBS-SSS symptom component scores. RESULTS: A total of 186 patients were randomised and 152 patients completed the study. The mean change in IBS-SSS was -63.3 probiotic vs. -28.3 placebo. The mean difference in the IBS-SSS was statistically significant [-35.0 (95% CI; -62.03, -7.87); P = 0.01]. There was no significant improvement in the IBS-QOL. No serious adverse events were reported. CONCLUSIONS: The multi-strain probiotic was associated with a statistically significant improvement in overall symptom severity in patients with IBS, and was well tolerated. These results suggest this probiotic confers benefit in IBS and deserves further investigation (ISRCTN identifier: 77512412).

An association between post-meal bile acid response and bone resorption in normal subjects.

BACKGROUND: The mechanism surrounding bone suppression after a meal may involve several mediators, but is yet to be clarified. Bile acids (BA) function as signalling molecules in response to feeding, and may be directly involved in bone suppression acutely after a meal. The aim of this study was to test the hypothesis that BA are involved in the acute bone suppression observed after a meal. METHODS: A prospective study in which samples collected from volunteers fed a 400 Kcal test meal after an overnight fast were analysed for parathyroid hormone (PTH), BA, and carboxyterminal of type 1 collagen telopeptide (CTX). The study was carried out in 10 healthy male volunteers. Ethical approval was obtained from the Local Research and Ethics Committee at King's College Hospital. RESULTS: Total BA, glycine conjugated bile acids (GCBA), PTH and CTX showed a response to meal ingestion. There was a negative correlation between percentage change in PTH and CTX (R (2 )= -0.82, P = 0.004), and between PTH and GCBA (R (2 )= -0.39, P = 0.005). CONCLUSION: This study demonstrated an association between GCBA and PTH suppression after a meal. The drop in PTH concentration after a meal may be responsible for the suppression of bone resorption as observed by the decrease in CTX concentration.

A patient with the rare alpha-1-antitrypsin variant (Z)bristol in compound heterozygosity with the Z mutation.

Alpha-1-antitrypsin (AAT) is a protease inhibitor (PI), deficiency of which is associated with emphysema and liver disease. The most common deficiency alleles are the S (p.Glu288Val) and Z (p.Glu366Lys) alleles. The Z allele predisposes the AAT protein to polymerization with accumulation in hepatocytes leading to liver disease in PIZ individuals. Most AAT variants have a characteristic pattern of isoforms by isoelectric focusing (IEF). A novel AAT variant called PIZbristol (p.Thr109Met) with an unusual pattern on IEF was described in 1997. We report a patient with the PIZZbristol phenotype that has not been previously described. A 43-year-old man was referred by his GP to a respiratory clinic for breathlessness. His AAT concentration was 0.50 g/L (reference range 1.0-2.0 g/L). An unusual pattern on IEF was seen and sequencing revealed the presence of the rare variant Zbristol in combination with the Z mutation. This is the second reported case of Zbristol and the first in combination with the Z mutation. The patient maintained plasma AAT concentrations around 0.50-0.70 g/L which suggested that the Zbristol protein contributed to the low plasma concentration of AAT. The clinical symptoms associated with PIZ are usually attributed to the plasma deficiency, but his only respiratory complaint was that of breathlessness. This suggests that the PIZZbristol phenotype may confer an effect on respiratory function but is not involved in liver disease.

Improved blood pressure, nitric oxide and asymmetric dimethylarginine are independent after bariatric surgery.

BACKGROUND: Obesity is associated with hypertension, but the exact mechanism is not fully understood. Bariatric surgery significantly decreases weight and blood pressure (BP). Low plasma nitric oxide (NO) and raised asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO, concentrations are associated with both obesity and hypertension. Correlations between the changes in these parameters were studied after bariatric surgery. METHODS: Weight, BP, plasma ADMA and NO were measured in 29 obese patients (24 female, 5 male) before and six weeks after bariatric surgery. RESULTS: Patients were 39.2 ± 1.2 (mean ± SEM) years old and weighed 126 ± 3 kg. Six weeks after the surgery, patients had lost 10 ± 0.7 kg (P < 0.0001) and mean arterial pressure (MAP) decreased by 11 ± 1.0 mmHg (P < 0.0001). The plasma ADMA concentration decreased by 24 ± 2% from 5 ± 0.4 to 4.0 ± 0.3 µmol/L (P < 0.0001). The plasma total nitrite concentration increased by 15 ± 1% from 51.4 ± 2.6 to 60 ± 3 µmol/L (P < 0.0001). The correlation between the decrease of ADMA and increase of NO subsequent to weight loss was significant (P < 0.0001). However, MAP was not correlated to the changes in ADMA or NO. CONCLUSIONS: After bariatric surgery, beneficial changes in BP, NO and ADMA occur, but our findings suggest that these BP changes are independent of changes in the NO-ADMA axis. Other causes for the changes in BP should therefore be considered.

Analysis of adipokine concentrations in paediatric non-alcoholic fatty liver disease.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in children. It is important to distinguish children with more severe disease or steatohepatitis (NASH) from those with the less severe simple steatosis (SS) as prognosis differs. The importance of adipokines in the evolution of NASH is well recognized. OBJECTIVE: As adipokines are important in mediating inflammation, they may also be useful biomarkers of disease. METHODS: Plasma from 40 children (30 boys), median age 13.4 years, with liver biopsy-proven NAFLD was analysed. Liver biopsies were scored using the NAFLD activity score and compared with adipokine concentrations. RESULTS: Median body mass index z-score was 2.12 with a median homeostasis model of assessment- insulin resistance of 4.08. Resistin was lower in NASH than in SS (P = 0.03). Monocyte chemoattractant protein 1 (MCP-1) was also lower in NASH (P = 0.04). MCP-1 was higher in children with severe fibrosis (P = 0.008) with an area under the receiver operating characteristic curve (AUROC) of 0.76. Plasminogen activator inhibitor 1 (PAI-1) was also higher in this group (P = 0.011) with an AUROC of 0.78. There were no significant differences in leptin, adiponectin, adipsin, interleukin (IL) 6, IL10 or tumour necrosis factor α between groups. CONCLUSION: PAI-1 MCP-1 and resistin were differentially expressed with increasing severity of NAFLD. Though it is unlikely that this profile alone would serve as a biomarker of disease, differences found may contribute to understanding the role of these mediators in NAFLD.

Leptin/adiponectin ratio in patients with coronary heart disease: comparing subjects with and without metabolic syndrome.

BACKGROUND: Adiponectin and leptin are adipose tissue-derived hormones, shown to have opposing associations with the metabolic syndrome and coronary heart disease (CHD). This study evaluated the association between the leptin/adiponectin ratio and the components of the metabolic syndrome in a cohort with CHD. Methods and results This cross-sectional study included data from 105 subjects (men = 91), undergoing first-time elective coronary artery bypass grafting (CABG). Leptin and adiponectin concentrations were determined by enzyme-linked immunosorbent assay (ELISA). Association was found between the leptin/adiponectin ratio and homeostatic model assessment (HOMA) (r(s) = 0.34, P = 0.0006), fasting insulin concentrations (r(s) = 0.37, P = 0.0001), fasting glucose concentrations (r(s) = 0.24, P = 0.01), systolic blood pressure (r(s) = 0.20, P = 0.05), diastolic blood pressure (r(s) = 0.24, P = 0.02), waist circumference (r(s) = 0.55, P < 0.0001), body mass index (BMI) (r(s) = 0.55, P < 0.0001) and waist/hip ratio (r(s) = 0.38, P = 0.0001). A significant difference was found in ratios between those with and without insulin resistance (HOMA > 3 and HOMA ≤ 3) (P = 0.029) and those with and without metabolic syndrome, defined by the International Diabetes Federation, (P < 0.001). However, using receiver operating characteristic (ROC) analysis and assessment of area under curve (AUC), the leptin/adiponectin ratio did not perform significantly better than its components. CONCLUSION: In patients with severe CHD, the leptin/adiponectin ratio was not found to be a robust tool to distinguish patients with and without insulin resistance and those with and without the metabolic syndrome.

The relationship between postprandial bile acid concentration, GLP-1, PYY and ghrelin.

BACKGROUND: Gut hormones peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) play an integral role in appetite control and energy homeostasis. Entero-endocrine L-cells can be stimulated by nutrients and or bile acids to co-secrete PYY and GLP-1. The aim of this study was to determine the response of bile acids, PYY, GLP-1 and ghrelin after a test meal. DESIGN: Twelve subjects with a BMI of 22·8 (0·52) kg/m² [mean (SEM)] received a 400 kcal test meal after which blood samples were taken every 30 min from 0 to 180 min. PYY, GLP-1 and ghrelin were measured by radioimmunoassays. Fractionated bile acids were measured by HPLC-MSMS. RESULTS: PYY positively correlated with glycochenodeoxycholic acid (GCDCA) (rs = 0·23, P = 0·03) and taurochenodeoxycholic acid (TCDCA) (rs = 0·26, P = 0·02). GLP-1 positively correlated with GCDCA (rs = 0·22, P = 0·047) and glycodeoxycholic acid (GDCA) (rs = 0·3, P = 0·005). Ghrelin negatively correlated with GDCA (rs = -0·45, P≤ 0·0001), TCDCA (rs = -0·23, P = 0·034) and taurodeoxycholic acid (TDCA) (rs = -0·44, P≤ 0·0001). CONCLUSION: PYY and GLP-1 responses correlated with chenodeoxycholic acid (CDCA) counterparts, whereas ghrelin negatively correlated with deoxycholic acid (DCA) counterparts. Specific bile acids may thus differentially affect entero-endocrine cells.

The neurological morbidity of carotid revascularisation: using markers of cellular brain injury to compare CEA and CAS.

AIM: This comparative study attempts to evaluate the profile of S-100beta and Neuron-Specific Enolase (NSE), biomarkers of brain injury, in patients undergoing carotid endarterectomy (CEA) and carotid artery stenting (CAS) and to correlate this with haemodynamic and embolic events detected using trans-cranial Doppler (TCD). METHODS: 52 patients with internal carotid artery stenosis requiring intervention were recruited. 24 patients underwent CAS, and 28 underwent CEA. TCD was performed peri-operatively to record mean Middle Cerebral Artery (MCA) velocity and number of High Intensity Transient Signals (HITS) in the MCA of the operated side. Serum was drawn pre-operatively and at six time points in a 48 hour post-operative period, and then assayed using automated commercial equipment. Within and between group variability in markers were assessed by Generalized Estimation Equations modelling. RESULTS: CAS caused more HITS (p=0.028) but less haemodynamic disturbance (p=0.0001) than CEA. Treatment modality (CAS versus CEA) had no direct effect on S-100 changes (p=0.467). NSE levels declined after revascularisation in the CAS group but not after CEA (p=0.002). S-100beta levels rose in patients who had higher numbers of HITS (p=0.002). S-100beta and NSE were not associated with changes in MCA velocity (p>0.5). S-100beta alone increased significantly at 24 hours in those patients with a post-operative neurological deficit (p=0.015). CONCLUSIONS: Trans-cranial Doppler findings suggest that the mechanisms of rise in S-100beta and NSE levels may differ and may be due to increased peri-operative micro-embolisation and cerebral hypoperfusion respectively. Further studies are required to assess the clinical significance of these observed changes.

M2-PK as a novel marker in ovarian cancer. A prospective cohort study.

BACKGROUND: Pyruvate kinase isoenzyme M2-PK is instrumental to tumour metabolism and hence over-expressed in tumour cells leading to detectable plasma concentrations. OBJECTIVES: To assess the degree of association between M2-PK plasma concentrations and ovarian cancer and to determine the cut-off values for its sensitivity and specificity for differentiating between benign and malignant ovarian disease. SETTINGS: The Gynaecological Cancer Centre at both King's College and St. Thomas' Hospitals, London, UK. METHODS: Patients with suspected ovarian cancer referred to the above centre were recruited prospectively during the years 2004-2005. Blood samples were collected before surgery for plasma M2-PK assays. Results were assessed with respect to cancer diagnosis, patient and tumour characteristics. Statistical analysis including the receiver operator characteristic (ROC) curve was performed using Analyse-It and SPSS V 13. RESULTS: 100 patients with age range 14-88 years and a median of 57 years were recruited in the study. Of whom 52 were diagnosed with invasive ovarian cancer. Of these 35 (67%) were Stage III and above with two secondary tumours. M2-PK was not related to patient age (p = 0.43). There was a significant correlation between CA125 and M2-PK (p < 0.001). The mean M2-PK concentration in cancer patients was 52 U/ml versus 27 U/ml in patients with benign conditions (p < 0.001). At a cut-off value of 22 U/ml the sensitivity of M2-PK for detecting cancer was 70% with a specificity of 65%. CONCLUSION: M2-PK was significantly raised in ovarian cancer patients, however its role in clinical practice needs further evaluation.

Tumour M2-PK as a predictor of surgical outcome in ovarian cancer, a prospective cohort study.

BACKGROUND: Optimal cytoreduction is a major prognostic factor in ovarian cancer; several clinical, radiological and biochemical predictors have been studied. Tumour M2-PK (TU M2-PK) is over-expressed in tumour cells and can be detected in plasma samples but its role in ovarian cancer has not yet been evaluated. OBJECTIVES: To assess the potential clinical applications of TU M2-PK in ovarian cancer particularly in relation to surgical cytoreduction. SETTINGS: The Gynaecological Cancer Centre at both King's College and St Thomas' Hospitals; London; UK. METHODS: Patients with suspected ovarian cancer were recruited prospectively during the years 2004-2005. Blood samples were collected before surgery for plasma TU M2-PK assays. Data were analysed in relation to cancer diagnosis and outcome. Statistical analysis was performed using Analyse-It' and SPSS' V13. RESULTS: 100 patients were recruited; 52 diagnosed with invasive ovarian cancer, 13 with borderline tumours and 35 patients had benign conditions. The mean M2-PK concentration in cancer patients was 52 U/ml vs 31 U/ml in patients with borderline tumours and 22 U/ml in those with benign conditions (p < 0.001); it was significantly raised in association with late stage disease and higher grade (p < 0.05). Taking 35 U/ml as a reference point, TU M2-PK predicted sub-optimal cytoreduction in advanced stage disease with a sensitivity of 69%, specificity of 60% and overall efficacy of 61% (95% CI: 44-75%). CONCLUSION: TU M2-PK was significantly raised in ovarian cancer patients, particularly those with higher stage disease. The potential clinical application as a predictor of surgical outcome in ovarian cancer needs further evaluation.

The pharmacokinetics of a single rectal dose of paracetamol (40 mg x kg(-1)) in children with liver disease.

BACKGROUND: The aim of our study was to measure the serum paracetamol concentrations achieved following a single rectal loading dose of 40 mg x kg(-1) in children with chronic liver disease. METHODS: We recruited 17 children (3-15 years, 10.6-75 kg) undergoing minor surgical procedures under general anesthesia. Paracetamol was administered at the end of surgery and blood samples were taken for analysis at 2, 3, 4, 6 and 8 h postdose. RESULTS: The mean Cmax of 11.4 mg x l(-1) [coefficient of variation (CV) 66%] was achieved at a Tmax of 2.7 h (CV 42%). The relative bioavailability (F) of the suppository formulation was not estimated, but clearance (Cl/F) estimates 0.73 l x kg(-1) x h(-1) (CV 87%) and time-concentration profiles for these children were similar to the normal pediatric population. CONCLUSIONS: There are currently no biologic markers available for monitoring possible hepatotoxicity in this cohort of patients with liver disease, but our data suggest that a single-dose suppository is a satisfactory analgesic alternative.

Prognostic role of cardiac troponin I after percutaneous coronary intervention in stable coronary disease.

OBJECTIVE: To assess the role of cardiac troponin I (cTnI) in predicting outcome after percutaneous coronary intervention (PCI). METHODS AND RESULTS: cTnI was measured immediately before and at 6, 14, and 24 hours after PCI in 316 consecutive patients with stable symptoms and native coronary artery disease. The study end point was the occurrence of major adverse cardiac events (MACE) at 30 days and at 18 months after PCI: death, Q wave myocardial infarction (MI), or repeat revascularisation in hospital. Postprocedural cTnI increased in 31% of patients. The cumulative MACE rate at 18 months was 25% (17.7% due to repeat PCI procedures). There was a significant association between postprocedural cTnI increase and death, Q wave MI, or both (odds ratio (OR) 3.28, 95% confidence interval (CI) 1.7 to 6.4, p = 0.01). Post-PCI cTnI increase had a positive predictive value (PPV) for adverse events at 18 months of 0.47 and a negative predictive value (NPV) of 0.96 (OR 18.9, 95% CI 9.7 to 37, p < 0.0001). The presence of both a postprocedural cTnI rise and a procedural angiographic complication gave a PPV for adverse events of 0.69 and an NPV of 0.92 (OR 22.6, 95% CI 2.6 to 68.6, p = 0.0005). CONCLUSIONS: cTnI increased post-procedurally in one third of this stable patient population undergoing elective PCI and was independently and significantly predictive of an increased risk of adverse events at 18 months, predominantly in the form of repeat PCI.

Evaluation of neuromuscular symptoms in UK Gulf War veterans: a controlled study.

OBJECTIVES: To determine whether Gulf War veterans with neuromuscular symptoms that included weakness and fatigue had either 1) objective correlates for muscle weakness or fatigue; or 2) any etiologic explanation for such symptoms; and if so, 3) whether such objective measures or etiologic mechanisms were specific to Gulf War service. METHODS: Forty-nine ill Gulf War veterans with more than four neuromuscular symptoms (Gulf-ill) were compared with 26 Gulf-well veterans, 13 symptomatic Bosnian veterans (Bosnia-ill), and 22 symptomatic troops who were not deployed to the Gulf (Era-ill). Quantitative myometry was used to objectively measure weakness and fatigue. Subjects had an ischemic forearm exercise test, a subanaerobic bicycle exercise test, and a muscle biopsy. RESULTS: Quantitative strength and fatigue measures did not correlate with self-perception of weakness or fatigue for any of our groups. No specific muscle biopsy abnormalities were found. There was no defect of adenylate deaminase or glycogenolysis found. Gulf-ill subjects did find the subanaerobic bicycle exercise more effortful and generated significantly higher plasma lactate concentrations compared with Gulf-well subjects. CONCLUSION: Because complaints of weakness and fatigue in unwell servicemen do not correlate with actual weakness or fatigue, explanations for these symptoms must lie outside of the neuromuscular system. Increased lactate production during subanaerobic bicycle exercise reflects mitochondrial inefficiency, but it is unclear whether this reflects mitochondrial damage sustained during Gulf War service or inactivity secondary to ill health.

Primary cultures of prostate cells and their ability to activate carcinogens.

Differences in the incidence of prostate cancer (CaP) amongst different migrant populations point to causative agents of dietary and/or environmental origin. Prostate tissues were obtained following transurethral resection of the prostate (TURP) or radical retropubic prostatectomy. After surgery, TURP-derived or tumour-adjacent tissue fragments were minced in warm PFMR-4A medium (37 degrees C) and suspensions pipetted into collagen-coated petri dishes. Non-adherent material was removed by washing with fresh medium after 12 h. Adhered cells subsequently reacted positively with monoclonal antibodies to prostate specific antigen (PSA). PSA was also detected in the medium. The genotoxicities of the chemical carcinogens 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (PhIP), its N-hydroxy metabolite (N-OH-PhIP) and benzo[a]pyrene (B[a]P) in adherent cell populations from different donors (n=8) were examined. Cells were treated in suspension for 30 min at 37 degrees C in the presence of the DNA repair inhibitors hydroxyurea (HU) and cytosine arabinoside (ara-C). DNA single-strand breaks were detected in cells by the alkaline single cell-gel electrophoresis ('Comet') assay and quantified by measuring comet tail length (CTL) in microm. All three carcinogens induced dose-related increases in CTLs (P<0.0001) in cells from four donors 24 h post-seeding. However, in cells from a further two donors the genotoxic effects of PhIP, N-OH-PhIP and B[a]P were much less apparent after 48 h than after 24 h in culture. After 96 h in culture, cells from these donors appeared to be resistant to the comet-forming activity of the compounds. However, B[a]P-DNA adducts were still measurable by (32)P-postlabelling for up to 14 days following a 24-h exposure to 50 microM B[a]P in adhered cells from another two donors. This study shows that primary cultures of cells derived from the prostate can activate members of two classes of chemical carcinogens. Further development may provide a robust model system in which to investigate the aetiology of CaP.

Folic acid enhances endothelial function and reduces blood pressure in smokers: a randomized controlled trial.

OBJECTIVE: Cigarette smoking is associated with increased plasma homocysteine concentrations, endothelial dysfunction and arterial stiffening. Homocysteine per se induces endothelial dysfunction and arterial stiffening and might account, at least partly, for the vascular abnormalities observed in smokers. We sought to determine whether folic acid supplementation, by reducing plasma homocysteine concentrations, enhanced endothelial function and reduced arterial stiffness in smokers. DESIGN: Double-blind, randomized controlled, parallel-group, trial. SETTING: Academic medical centre. SUBJECTS: A consecutive sample of 24 healthy cigarette smokers (age 37.8 +/- 2.5 years, mean +/- SEM). INTERVENTION: Subjects were randomly assigned to 4-week folic acid 5 mg day-1 or placebo. MAIN OUTCOME MEASURES: The following were measured before and after treatment: (i) peripheral vasoreactivity (forearm arterial blood flow, FABF) during intra-arterial administration of endothelium-dependent (acetylcholine 1.5, 4.5 and 15 microg min-1) and endothelium-independent (sodium nitroprusside 1, 2 and 4 microg min-1) vasodilators; (ii) carotid-femoral pulse-wave velocity (PWV); (iii) blood pressure (BP). RESULTS: Folic acid reduced homocysteine concentrations (10.8 +/- 0.6 vs. 8.2 +/- 0.5 micromol L-1, P < 0.001) and enhanced endothelium-dependent vasodilatation during each acetylcholine infusion rate (ratio between the FABF in the infused and control arm during increasing infusion rates at baseline 1.09 +/- 0.03 vs. 1.41 +/- 0.09 after treatment, P < 0.01; 1.39 +/- 0.07 vs. 1.83 +/- 0.12, P < 0.01; 1.65 +/- 0.16 vs. 2.72 +/- 0.36, P < 0.05) whilst endothelium-independent vasodilatation was unaffected. A significant fall in BP was also observed (mean BP 88 +/- 2 vs. 83 +/- 1 mmHg, P < 0.01). By contrast, PWV did not significantly change (8.4 +/- 0.3 vs. 7.8 +/- 0.4 m s-1). No significant changes in plasma homocysteine concentrations, FABF, BP, and PWV were observed in the placebo group. A multiple regression analysis showed that changes in folic acid plasma concentrations independently predicted both FABF changes during maximal acetylcholine-mediated vasodilatation (P < 0.01) and BP changes (P = 0.01). CONCLUSIONS: Short-term folic acid supplementation significantly enhanced endothelial function and reduced BP in young chronic smokers. These effects were largely independent from the homocysteine lowering effects. Thus, a simple, nontoxic, and relatively inexpensive vitamin intervention might be useful in primary cardiovascular prevention in this high-risk group.

Cardioprotective effect of propranolol from alcohol-induced heart muscle damage as assessed by plasma cardiac troponin-t.

BACKGROUND: Heavy alcohol consumption from either long-term misuse or binge drinking is associated with poor cardiac contractility, mitochondrial dysfunction, and ventricular arrhythmias. The aim of this study was to measure circulating cardiac troponin-T as a marker for myocardial damage following acute and chronic alcohol administration. METHODS: In acute studies, male Wistar rats were treated with alcohol (75 mmol/kg body weight, intraperitoneal) and plasma was collected 2.5 hr after alcohol administration for analysis of rat cardiac troponin-T. In addition, rats were pretreated with cyanamide (an inhibitor of acetaldehyde dehydrogenase), various beta-blockers, xanthine oxidase inhibitors, or lisinopril before acute alcohol dosing. In chronic studies, rats were fed alcohol (as 35% of total dietary calories) for 6 weeks. RESULTS: The results of the time course study showed that acute alcohol administration significantly raised plasma cardiac troponin-T levels after 2.5 hr and 6 hr, but not after 24 hr. The effects of alcohol on cardiac troponin-T were potentiated with cyanamide pretreatment. Acute ethanol, alone or with cyanamide pretreatment, decreased systolic blood pressure and increased heart rates. Beta-blocker pretreatment with propranolol reduced the alcohol-induced increase in plasma troponin-T, whereas lisinopril potentiated this effect. The beta-blockers, atenolol and metoprolol, and the xanthine oxidase inhibitors, allopurinol and oxypurinol, were unable to reduce elevated troponin-T. However, pretreatment with the beta-blocker timolol moderated the acute alcohol-induced increase in troponin-T. In the chronic alcohol rat model, no differences were observed between alcohol and control pair-fed rats, suggesting the inducement of tolerance. CONCLUSIONS: In conditions of acute exposure, ethanol-induced lesions are characterized by raised plasma cardiac troponin-T possibly due to beta1 and/or beta2 adrenergic activation.