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Biomedical subjects

S P Pereira

Publications and source records attributed to S P Pereira.

At least 19 recordsLinked to original sources
PubMed2006

Systematic review: sphincter of Oddi dysfunction--non-invasive diagnostic methods and long-term outcome after endoscopic sphincterotomy.

BACKGROUND: Sphincter of Oddi dysfunction is a benign, functional gastrointestinal disorder for which invasive endoscopic therapy with potential complications is often recommended. AIMS: To review the available evidence regarding the diagnostic accuracy of non-invasive methods that have been used to establish the diagnosis and to estimate the long-term outcome after endoscopic sphincterotomy. METHODS: A systematic review of English language articles and abstracts containing relevant terms was performed. RESULTS: Non-invasive diagnostic methods are limited by their low sensitivity and specificity, especially in patients with Type III sphincter of Oddi dysfunction. Secretin-stimulated magnetic resonance cholangiopancreatography appears to be useful in excluding other potential causes of symptoms, and morphine-provocated hepatobiliary scintigraphy also warrants further study. Approximately 85%, 69% and 37%, of patients with biliary Types I, II and III sphincter of Oddi dysfunction, respectively, experience sustained benefit after endoscopic sphincterotomy. In pancreatic sphincter of Oddi dysfunction, approximately 75% of patients report symptomatic improvement after pancreatic sphincterotomy, but the studies have been non-controlled and heterogeneous. CONCLUSIONS: Patients with suspected sphincter of Oddi dysfunction, particularly those with biliary Type III, should be carefully evaluated before considering sphincter of Oddi manometry and endoscopic sphincterotomy. Further controlled trials are needed to justify the invasive management of patients with biliary Type III and pancreatic sphincter of Oddi dysfunction.

Common Bile Duct Diseases↗
PubMed2006

Endoscopic ultrasound-guided tissue sampling by combined fine needle aspiration and trucut needle biopsy: a prospective study.

BACKGROUND AND AIMS: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has a diagnostic accuracy of 70-90%, depending on the site under evaluation. In order to improve EUS-guided tissue sampling a novel 19-gauge trucut-type needle has been designed to obtain core biopsies during EUS. We prospectively evaluated the safety and accuracy of EUS-FNA alone versus combined EUS-FNA and trucut needle biopsy (TNB) in patients referred to our Unit over a 3-year period. PATIENTS AND METHODS: A total of 159 patients underwent EUS-FNA alone (lesions<2 cm) or the combination of both sampling modalities (lesions>or=2 cm). The adequacy of sampling, sensitivity, specificity and overall accuracies of EUS-FNA or EUS-TNB alone and combined EUS-FNA/TNB were determined. RESULTS: Adequate samples were obtained by EUS-FNA, EUS-TNB and EUS-FNA/TNB in 91%, 88% and 97% of patients, respectively. From the pancreas (n=83), adequate samples were obtained by FNA in 94% and by TNB in 81%, compared with 87% and 92% from non-pancreatic sites (n=76), respectively. The combination of both techniques resulted in more adequate samples from non-pancreatic cases than EUS-FNA alone (P=0.044). The specificity was 100%. Overall accuracy for EUS-FNA alone was 77%, for EUS-TNB alone 73% and for EUS-FNA/TNB 91% (P=0.008). For pancreatic sampling, the accuracy of EUS-FNA alone was 77%, for EUS-TNB alone 56% and for EUS-FNA/TNB 83%. For non-pancreatic sampling, the accuracy for EUS-FNA alone was 78%, for EUS-TNB alone 83% and for EUS-FNA/TNB 95% (P=0.006). The complication rate was 0.6%. CONCLUSIONS: Combined EUS-FNA/TNB for lesions>or=2 cm improves adequacy of sampling and diagnostic accuracy compared with either technique alone and is safe.

Aged↗
PubMed2006

Biochemical markers of acute pancreatitis.

Serum amylase remains the most commonly used biochemical marker for the diagnosis of acute pancreatitis, but its sensitivity can be reduced by late presentation, hypertriglyceridaemia, and chronic alcoholism. Urinary trypsinogen-2 is convenient, of comparable diagnostic accuracy, and provides greater (99%) negative predictive value. Early prediction of the severity of acute pancreatitis can be made by well validated scoring systems at 48 hours, but the novel serum markers procalcitonin and interleukin 6 allow earlier prediction (12 to 24 hours after admission). Serum alanine transaminase >150 IU/l and jaundice suggest a gallstone aetiology, requiring endoscopic retrograde cholangiopancreatography. For obscure aetiologies, serum calcium and triglycerides should be measured. Genetic polymorphisms may play an important role in "idiopathic" acute recurrent pancreatitis.

Acute Disease↗
PubMed2005

A controlled trial of ondansetron in the pruritus of cholestasis.

BACKGROUND: In patients with pruritus of cholestasis, response to conventional drug treatment may be unsatisfactory. Activation of 5-hydroxytryptamine receptors on dermal sensory nerve-endings plays a role in the perception of pruritus. The 5-hydroxytryptamine(3) receptor antagonist, ondansetron, has been used in the treatment of pruritus of cholestasis, but there are few controlled data. AIM: To determine whether ondansetron is effective in treating the pruritus of cholestasis. METHODS: A total of 19 patients with resistant pruritus were randomized, double blind, to receive either ondansetron 8 mg or placebo as a single intravenous bolus, followed by oral ondansetron 8 mg or placebo twice daily for 5 days. Patients' perception of pruritus was recorded hourly using a visual analogue scale, and scratching activity measured by means of a piezo-electric crystal attached to the fingernail. RESULTS: Mean pruritus score using visual analogue scale and scratching activity were reduced on the first treatment day compared with baseline in both the ondansetron and placebo groups (P < 0.05), but there were no significant differences in mean pruritus perception or scratching activity between the two groups. CONCLUSION: Ondansetron was of no benefit in this group of pruritic patients during short-term treatment.

Adult↗
PubMed2004

Transdermal hormone replacement therapy improves vertebral bone density in primary biliary cirrhosis: results of a 1-year controlled trial.

BACKGROUND: Retrospective studies have suggested that hormone replacement therapy may reduce the rate of bone loss in primary biliary cirrhosis, but no controlled data are available. METHODS: Forty-two post-menopausal women with primary biliary cirrhosis were treated with calcium and vitamin D, either alone (n = 21) or together with transdermal hormone replacement therapy (n = 21). Bone densitometry was performed at baseline and at 1 year, and serum and urinary markers of bone turnover were measured at three-monthly intervals. RESULTS: At entry, 17 patients (40%) had spinal or femoral osteopenia (T score - 1 to - 2.5) and nine (21%) had osteoporosis (T < - 2.5). In those given hormone replacement therapy, there was a significant decrease in the mean urinary deoxypyridinoline :creatinine ratios at 3 months (7.8 vs. 6.1 nm/mm creatinine for no hormone replacement therapy vs. hormone replacement therapy; P = 0.04) and a 48% reduction in urinary calcium excretion at 1 year (0.66 vs. 0.32 mm/mm creatinine; P = 0.01). Repeat bone densitometry at 1 year revealed a 2.25% increase in the hormone replacement therapy group (P = 0.02), compared with a non-significant 0.87% decrease in L2-L4 bone mineral density in those not given hormone replacement therapy. Both treatment regimens were well tolerated, with no increase in cholestasis. CONCLUSIONS: Compared with calcium and vitamin D alone, supplemental treatment with transdermal hormone replacement therapy for 1 year improved the vertebral bone density and urinary markers of bone turnover in post-menopausal women with primary biliary cirrhosis.

Administration, Cutaneous↗
PubMed2003

Bile composition in inflammatory bowel disease: ileal disease and colectomy, but not colitis, induce lithogenic bile.

BACKGROUND: Inflammatory bowel disease is a risk factor for gall-bladder stones, but there is controversy about the composition of these stones and whether such patients develop lithogenic bile. METHODS: In 54 gallstone-free inflammatory bowel disease patients and 13 non-inflammatory bowel disease patients with cholesterol-rich gallstones, we measured the biliary cholesterol saturation indices, nucleation times and bilirubin concentrations, and determined the bile acid composition and molecular species of phosphatidylcholine, in gall-bladder bile. RESULTS: Patients with Crohn's colitis or ulcerative colitis had less saturated bile (mean cholesterol saturation index, 0.9) and longer nucleation times (median, 21 days) than those with ileal Crohn's disease (1.5; 14 days) or those who had undergone colectomy (1.6; 5 days). In patients with ileal Crohn's disease, the mean biliary bilirubin concentration was two- to three-fold higher than that in the other groups, and was associated with a decrease in the percentage of biliary deoxycholate and an increase in the percentage of ursodeoxycholate, compared with disease controls, but phosphatidylcholine species were similar. CONCLUSIONS: Patients with small bowel Crohn's disease, or who have undergone colonic resection, have supersaturated bile and an increased risk of cholesterol gallstone formation. In patients with ileal disease, the presence of high biliary bilirubin concentrations and low percentage of deoxycholic acid may also favour the formation of mixed, pigment-rich, gallstones.

Adult↗
PubMed2003

Intestinal absorption of mixed micellar phylloquinone (vitamin K1) is unreliable in infants with conjugated hyperbilirubinaemia: implications for oral prophylaxis of vitamin K deficiency bleeding.

OBJECTIVE: To compare the pharmacokinetics and efficacy of oral versus intravenous mixed micellar vitamin K prophylaxis in infants with cholestatic liver disease, a known risk factor for vitamin K deficiency bleeding. DESIGN: Prospective randomised controlled study. SETTING: Paediatric Liver Unit. PATIENTS: Forty four infants less than 6 months of age with conjugated hyperbilirubinaemia. MAIN OUTCOME MEASURES: Serum concentrations of vitamin K(1) and undercarboxylated prothrombin (PIVKA-II; a sensitive functional indicator of vitamin K status) before and for up to four days after a single dose of mixed micellar K(1) 1 mg intravenously or 2 mg orally. Comparison of K(1) levels 24 hours after oral K(1) with those from 14 healthy newborns given the same dose. RESULTS: At admission, 18 infants (41%) had elevated levels of serum PIVKA-II and eight (18%) had low K(1) concentrations, indicative of subclinical vitamin K deficiency. Median serum K(1) concentrations were similar in the oral and intravenous groups at baseline (0.92 v 1.15 ng/ml), rising to 139 ng/ml six hours after intravenous K(1) but to only 1.4 ng/ml after oral administration. In the latter group, the low median value (0.95 ng/ml) and wide range (< 0.15-111 ng/ml) of serum K(1) compared unfavourably with the much higher levels (median 77, range 11-263 ng/ml) observed in healthy infants given the same oral dose, and suggested impaired and erratic intestinal absorption in cholestatic infants. The severity of malabsorption was such that only 4/24 (17%) achieved an incremental rise in serum K(1) > 10 ng/ml. CONCLUSIONS: The intestinal absorption of mixed micellar K(1) is unreliable in infants with conjugated hyperbilirubinaemia. Given the strong association between cholestasis and late vitamin K deficiency bleeding, these data provide an explanation for the failure of some oral vitamin K(1) prophylaxis regimens in infants with latent cholestasis.

Administration, Oral↗
PubMed2001

Cholinergic activity modulates the survival of retinal ganglion cells in culture: the role of M1 muscarinic receptors.

The control of natural cell death is mediated by neurotrophins released by target, afferent and glial cells. In the present work we show that treatment of retinal cells 'in vitro' for 48 h with 25 microM carbamylcholine induced a two-fold increase in retinal ganglion cells survival. This effect was dose-dependent and mediated by M1 receptors since it could be blocked by 1 microM telenzepine (a M1 receptor antagonist) and mimicked by 200 microM oxotremorine (a M1 receptor agonist). The effect of carbamylcholine was abolished by 10 microM BAPTA-AM (an intracellular Ca2+ chelator), 30 microM dantrolene (an inhibitor of ryanodinic receptors), 500 nM H-89 (an inhibitor of PKA), 1.25 microM chelerythrine chloride (an inhibitor of PKC) and 50 microM PD-98059 (a MEK inhibitor). Treatment with 10 microM genistein (an inhibitor of tyrosine kinase), 25 microM LY-294002 (a PI-3 kinase blocker), 30 nM brefeldin-A (a blocker of polypeptides release), 50 nM K-252a (a Trk receptor inhibitor) and 20 microM fluorodeoxyuridine (an inhibitor of cell proliferation) totally inhibited the effect of carbamylcholine. Taken together our results indicate that muscarinic activity controls the survival of retinal ganglion cells through a mechanism involving the release of polypeptides and activation of Irk receptors.

Acetylcholine↗
PubMed2001

Octreotide increases the proportions of arachidonic acid-rich phospholipids in gall-bladder bile.

BACKGROUND AND AIMS: Octreotide treatment of acromegalic patients induces cholesterol gallstone formation, in part by impairing cholecystokinin release and gall-bladder contraction. However, there are few data on the effect of octreotide on biliary arachidonic acid-rich phospholipids or mucin glycoprotein, factors which also influence cholesterol gallstone formation. METHODS: In acromegalic patients studied before and during 3 months of octreotide treatment, we measured mucin glycoprotein concentrations and the molecular species of phosphatidylcholine, and related the results to the cholesterol saturation and percentage of deoxycholic acid in gall-bladder bile. RESULTS: The relative proportions of the major arachidonic acid-rich phosphatidylcholine species, PC 16:0-20:4 and PC 18:0-20:4, increased significantly during octreotide treatment. These changes were associated with a rise in the cholesterol saturation index and a non-significant twofold increase in mucin glycoprotein concentration. There were significant correlations between PC 16:0-20:4 and the cholesterol saturation index, percentage of vesicular cholesterol and percentage of deoxycholic acid in gall-bladder bile. CONCLUSIONS: In acromegalic patients, octreotide increases the proportions of arachidonic acid-rich phospholipids, with associated rises in: (a) the cholesterol saturation index and percentage of vesicular cholesterol, and (b) the percentage of deoxycholic acid in gall-bladder bile-changes similar to those found in patients with cholesterol-rich gall-bladder stones.

Acromegaly↗
PubMed2000

Quality of life after liver transplantation for alcoholic liver disease.

There are few data on predictive factors for alcohol relapse or long-term functional outcome after liver transplantation for alcoholic liver disease (ALD). In all 56 surviving UK patients (47 men, 9 women; mean age: 51 years; range: 33 to 69 years) who underwent transplantation for ALD at King's College Hospital over a 10-year period, alcohol relapse and outcome were assessed by outpatient and case-note review and by postal questionnaire containing (1) the Nottingham Health Profile (NHP), (2) the Short-Form-36 (SF-36) Health Survey, and (3) a drug and alcohol questionnaire. At a median of 2.5 years (range: 0.5 to 10 years), 13 of the 47 respondents (28%) and 2 of the 9 nonrespondents (22%) had evidence of potentially harmful drinking (>3 units daily) at some time posttransplantation. An additional 13 patients admitted to drinking some alcohol at least once, corresponding to an overall relapse rate of 50%. The patients with harmful drinking (1) had started drinking regularly at a younger age (18 v 25 years; P =.01), (2) began drinking heavily at a younger age (30 v 40 years; P =.01), (3) had shorter pretransplantation abstinence periods (10 v 23 months; P =.02), and (4) had a longer time since transplantation (median, 5.7 v 1.5 years; P =.0004) than those with no or mild alcohol relapse. They were also more likely to report sleep disturbance (NHP sleep problem score, 45 v 16; P =.01) and use benzodiazepines regularly (7 of 13 v 3 of 34 patients; P =.002). Despite these differences, health dimension scores in the SF-36 and NHP posttransplantation were similar between the groups and to those of UK community controls. In the long term, at least 50% of the patients will drink again at some time posttransplantation, although at lower levels of alcohol intake than previously. Those patients with multiple predictive factors for alcohol relapse may be at greatest risk for harmful drinking and be the group that would benefit most from professional counseling. Overall, the quality of life after liver transplantation for ALD is high and broadly similar to the levels expected in the normal population.

Adult↗
PubMed2000

A prospective, randomized comparison of the ease and safety of variceal ligation using a multiband vs. a conventional ligation device.

BACKGROUND AND STUDY AIMS: Recent advances in endoscopic technology have led to the development of multiple-banding devices which avoid the use of an overtube in endoscopic variceal ligation. In the present study we prospectively examined the safety and efficacy of one such device compared with the conventional single-band ligator. PATIENTS AND METHODS: A total of 45 patients undergoing band ligation were randomly assigned to receive ligation using conventional techniques (n = 22), or multiband ligation (n = 23). RESULTS: The use of the multiband device was associated with a significant reduction in sedation requirements (midazolam 7.1 mg vs. 9.9 mg, P < 0.01, multiband vs. conventional, respectively), less discomfort (4% vs. 23% severe discomfort, P < 0.05). The total time of the endoscopic session was reduced in the multiband group (8 minutes 25 seconds vs. 12 minutes 21 seconds, P < 0.01), as was the time required for application of all the bands (2 minutes 22 seconds vs. 5 minutes 34 seconds, P < 0.001), and average time taken per individual band application (36 seconds vs. 1 minute 36 secs, P < 0.01). In three patients who underwent ligation using the conventional method, the procedure was stopped because of trauma secondary to overtube application. CONCLUSIONS: Multiband ligation is safer, quicker, and associated with less patient discomfort and morbidity when compared with conventional ligation.

Adult↗
PubMed1999

Non-invasive assessment of bone density in primary biliary cirrhosis.

BACKGROUND/AIMS: Low bone mass is an important complication of primary biliary cirrhosis (PBC), resulting in an increased risk of fractures and reduced mobility. In the present study, we sought to determine the frequency of low bone mass in PBC, and its relationship to disease severity and non-invasive markers of bone turnover. METHODS: In 36 women with PBC, bone mineral density of the lumbar spine and hip was assessed by dual emission X-ray absorptiometry. Serum and urinary markers of bone turnover were compared with those from age- and sex-matched controls. RESULTS: Spinal osteopenia (T score, -1.5 to -2.5) was present in 15 of the 36 patients (42%), while six others (16%) had established osteoporosis (T < -2.5). Osteopenia of the femoral neck was found in 17 patients (47%), and osteoporosis in five (14%). The severity of liver disease, as determined by Mayo Clinic R score and histological stage, correlated negatively with both regional bone mineral density and total bone mineral content expressed as a ratio to lean body mass. There was a strong positive correlation between serum levels of the procollagen degradation peptides, PICP and PIIINP (r = 0.65, P < 0.001), and both peptides correlated significantly (P < 0.001) with histological stage and Mayo Clinic R score. Fasting urinary pyridinoline and deoxypyridinoline to creatinine ratios were also significantly raised. CONCLUSIONS: Low bone mass in PBC correlates positively with disease severity, and is associated with a net increase in bone resorption, as assessed by urinary collagen cross-link excretion. These markers of bone turnover may be of value in controlled clinical trials aimed at improving bone mass in PBC.

Absorptiometry, Photon↗
PubMed1999

Sclerosing mesenteritis involving the pancreas: two cases of a rare cause of abdominal mass mimicking malignancy.

Two patients presented with abdominal pain and weight loss and each was found to have an abdominal mass involving the pancreas and small bowel mesentery. In both cases a malignant process was suspected clinically, radiologically and surgically. Multiple biopsy specimens in both patients showed dense fibrosis, chronic inflammation and fat necrosis with pancreatic infiltration. Histological opinions included the differential diagnosis of retroperitoneal fibrosis but, with the knowledge of the presence of localized masses, these cases were eventually considered to be due to sclerosing mesenteritis. Direct involvement of the pancreas has not previously been highlighted and led to diagnostic difficulty. Both patients have responded to treatment with corticosteroids. Interestingly, one of the patients subsequently developed a tubulo-interstitial nephritis, which has not previously been reported as associated with sclerosing mesenteritis. This has also responded to corticosteroid treatment.

Adult↗
PubMed1998

Adverse events associated with vitamin K1: results of a worldwide postmarketing surveillance programme.

We compared adverse events associated with a conventional vitamin K(1) preparation, Konakion, with a new mixed micellar formulation, Konakion MM. Data were obtained worldwide from spontaneous reports, clinical trials and postmarketing surveillance. During the period 1974 to July 1995, an estimated 635 million adults and 728 million children were prescribed Konakion or Konakion MM. Of the 404 adverse events in 286 subjects reported, 387 (96%) were associated with Konakion. Konakion MM accounted for 4% (n=17) of the reported adverse events, and 5% of total sales figures. Thirteen of the 17 adverse events (76%) reported for Konakion MM were minor injection site reactions. Overall, 120 of the adverse events were serious, of which 117 (98%) were associated with Konakion. Eighty-five probable anaphylactoid reactions (of which six were fatal) were reported for conventional Konakion, compared with one non-fatal anaphylactoid reaction for Konakion MM. During the last 12 months of postmarketing surveillance, there were 14 serious adverse events reported in an estimated 21 million individuals treated with Konakion, but none in the 13 million who received Konakion MM. These results suggest that the Cremophor EL-solubilized preparations of vitamin K(1) have a higher profile of adverse events, including anaphylactoid reactions, than the newer mixed micellar preparation, Konakion MM.

Journal Article↗
PubMed1998

Biliary lactoferrin concentrations are increased in active inflammatory bowel disease: a factor in the pathogenesis of primary sclerosing cholangitis?

1. One hypothesis for the link between inflammatory bowel disease and primary sclerosing cholangitis is that neutrophil activators, such as bacterial chemotactic peptides or neutrophil granule products themselves, pass from the inflamed colon to the liver via an enterohepatic circulation. However, there are no data on biliary concentrations of neutrophil granule products in patients with active and inactive inflammatory bowel disease.2. Gall bladder bile was obtained at laparotomy from 42 patients with ulcerative colitis and 21 patients with Crohn's disease. Biliary lactoferrin and myeloperoxidase concentrations were quantified by ELISA.3. In active ulcerative colitis, the mean lactoferrin concentration in gall bladder bile of 2.8+/-0.40 mg/l was higher than that seen after colectomy (1.2+/-0.11 mg/l; P<0.0001) or in patients with pouchitis (1.8+/-0.34 mg/l; P=0.06). In active Crohn's colitis, the mean lactoferrin concentration was 3.7+/-0.9 mg/l, compared with 1.1+/-0. 24 mg/l in the post-colectomy group (P<0.05) and 3.1+/-0.71 mg/l in those with active ileitis or ileocolitis. In contrast, biliary myeloperoxidase concentrations were low and comparable in all groups, with a mean concentration in the 42 patients with ulcerative colitis of 11.2+/-1.9 microgram/l.4. In contrast to myeloperoxidase, biliary lactoferrin concentrations are increased in active ulcerative colitis and Crohn's disease, and fall with colectomy and with disease remission. These findings indirectly support the hypothesis that bacterial chemotactic peptides (which induce selective degranulation of neutrophil secondary granules), and/or lactoferrin itself, undergo an enterohepatic circulation.

Acute Disease↗