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Biomedical subjects

V Skar

Publications and source records attributed to V Skar.

At least 19 recordsLinked to original sources
PubMed2003

Oats induced villous atrophy in coeliac disease.

The current trend is to allow coeliac disease (CD) patients to introduce oats to their gluten free diet. We sought further data from the clinical setting with regards to oats consumption by coeliac patients. Several oat products were tested for wheat contamination using a commercial enzyme linked immunoassay (ELISA) kit, and six samples were examined by an ELISA using a cocktail of monoclonal antibodies, mass spectrometry, and western blot analysis. Nineteen adult CD patients on a gluten free diet were challenged with 50 g of oats per day for 12 weeks. Serological testing and gastroduodenoscopy was performed before and after the challenge. Biopsies were scored histologically and levels of mRNA specific for interferon gamma were determined by reverse transcription-polymerase chain reaction analysis. Oats were well tolerated by most patients but several reported initial abdominal discomfort and bloating. One of the patients developed partial villous atrophy and a rash during the first oats challenge. She subsequently improved on an oats free diet but developed subtotal villous atrophy and dramatic dermatitis during a second challenge. Five of the patients showed positive levels of interferon gamma mRNA after challenge. Some concerns therefore remain with respect to the safety of oats for coeliacs.

Adult↗
PubMed2002

D-glucaric acid in common duct bile and relation to choledocholithiasis.

BACKGROUND: The aim was to investigate a possible association between D-glucaric acid (DGA), biliary bilirubin glucuronidation and brown pigment stones in the common bile duct. METHODS: A high performance liquid chromatography method with a strong cation resin (HPX-87H) was developed for measuring biliary DGA. Bile was obtained during ERCP by deep cannulation of the common bile duct in 100 patients with suspected biliary disease. RESULTS: The concentration of DGA in common bile duct bile was 60 (1.1-633) micromol l(-1) (median, range). The values were lower than previously reported. There were no differences in DGA concentrations in patients with common bile duct stones compared to patients without common bile duct stones, irrespective of stone type, cholesterol or brown pigment stones. Bilirubin conjugates in common duct bile did not vary with DGA concentrations. CONCLUSION: DGA is probably insignificant in the pathogenesis of common bile duct stones.

Bile↗
PubMed2002

Collaboration by use of the Internet yields data of high quality and detects non-uniform management of patients with Helicobacter pylori infection.

BACKGROUND: The benefits of new technology steadily being introduced in medicine should be documented. In this study, remote entry of a set of data from the daily routine was submitted via the Internet to a common database. The usefulness and quality of the information are evaluated. METHODS: Fourteen hospitals reported a common data set on consecutive Hp+ve patients handled in accordance with daily practice. Participants submitted their data via the Internet to a database. There was no monitoring or other surveillance. No audit was planned or expected, but was nevertheless possible. Doctor compliance with the common agreement was checked, differences in medical practice were noted and quality was assessed comparing the most important source data with the data in the final database. RESULTS: Four-hundred-and-forty patients were included. The quality of the reported data was high, only 1.3% showing a discrepancy between source data and the database. Overall treatment success was 89%, with no significant differences between hospitals. There were significant differences in clinical practice between the centres, the proportion of patients treated for ulcer disease varying from 36% to 96% (P < 0.001). Doctor compliance with the agreed collaboration varied significantly (P < 0.001). CONCLUSION: Internet collaboration through remote data entry in a common database yields data of high quality without monitoring, and is a powerful and resource economic tool for clinical multicentre trials and quality assurance.

Clinical Trials as Topic↗
PubMed2000

Brown pigment stones in the common bile duct: reduced bilirubinate diconjugate in bile.

BACKGROUND: Bilirubin is the main component of most common bile duct stones. Normally, almost all bilirubin in bile is conjugated to glucuronic acid or some other sugar moiety. These conjugates are unstable and liable to deconjugation. Unconjugated bilirubin is insoluble and may precipitate as the calcium salt found in brown pigment stones. The pattern of bilirubin conjugates in common duct bile of patients with choledocholithiasis has been unknown. METHODS: In a clinical series of 55 patients with choledocholithiasis common-duct bile was aspirated, and the bilirubin conjugates analyzed with high-performance liquid chromatography. One stone from each patient was analyzed for cholesterol and bilirubin content to determine stone type. RESULTS: Sixteen patients had cholesterol stones, 38 patients had brown pigment stones, and 1 patient had a black stone. Patients with pigment stones had a lower percentage of bilirubin diglucuronide (median, 60.3%; interquartile range, 49.7%-67.3%) than patients with cholesterol stones (64.0%; 60.2%-73.3%) (Mann-Whitney, P=0.015). No significant difference was found for the other bilirubin conjugates, total bilirubin, or biliary pH when pigment and cholesterol stone patients were compared. The time of bile sampling in relation to papillotomy and treatment of cholestasis was not associated with the low percentage of bilirubin diglucuronide. The observation of reduced values for bilirubin diglucuronide could not be ascribed to duodenal diverticula or Billroth-II gastric resection. CONCLUSION: The percentage of the main bilirubinate conjugate, bilirubin diglucuronide, is decreased in the common duct bile of patients with pigmented compared with cholesterol stones.

Aged↗
PubMed2000

Structure and composition of common bile duct stones in relation to duodenal diverticula, gastric resection, cholecystectomy and infection.

BACKGROUND: Common bile duct stones represent a clinical problem often involving severe infection, cholangitis and cholestasis. Stasis and infection are thought to play a part in the pathogenesis of choledocholithiasis. Investigations on the etiology of common bile duct stones are, however, scarce because of the difficult access to common bile duct stones and bile. In a clinical series of common bile duct stones, we studied the gross appearance of stones extracted endoscopically from the common bile duct and measured the cholesterol and bilirubinate content in order to elucidate factors of importance to etiology. METHODS: In 135 patients treated endoscopically for bile duct stones, the stones or parts of the stones were collected. Appearances of the cut surface of the stones were studied and described. Cholesterol and bilirubinate content were analyzed enzymatically and with infrared spectroscopy. The growth in bile of gas-producing bacteria previously shown to be correlated with enterobacteriacea was investigated. RESULTS: Seventy-five percent of the stones were pigment stones, the majority with concentric pigmented layering. There was good agreement between cholesterol measurements. With a cutoff at 50% for the infrared measurements and 25% for the enzymatic assay only 3 stones were discordant between cholesterol measurements and visual inspection. Twenty-one of 23 patients with a previous Billroth-II gastric resection had pigment stones (p < 0.05). Gas-producing bacteria were significantly more prevalent in the bile from patients with layered pigment stones. CONCLUSION: Pigment stones with concentric layering highly suggestive of a cyclic process of crystallization were recovered from the common bile duct in 70% of the patients in our series.

Adult↗
PubMed1998

Changes in small intestinal structure and function in HIV-infected patients with chronic diarrhoea.

Human immunodeficiency virus (HIV) is often combined with unexplainable diarrhoea and weight loss. This study was designed to see if changes in the intestinal mucosal structure could explain the malabsorption found in HIV-infected patients with diarrhoea. Twenty acquired immunodeficiency system (AIDS) patients, 19 men and 1 woman, CD4 < 0.01, with severe weight loss and with non-infectious chronic diarrhoea, were evaluated using a new intestinal function test (D-xylose breath test). Fifteen of the subjects were examined with an upper intestinal endoscopy with biopsy specimens taken from the duodenal mucosa. The function test showed that the D-xylose uptake was markedly decreased to the same extent as for patients with coeliac disease (breath index AIDS patients 9.4 (4.3-14.4), coeliac patients 15.6 (7.6-23.6), reference level 2.5 (2.4-2.9), urine excretion AIDS patients 20% (13-26), coeliac patients 22% (14-24), reference level 37% (32-42)). The severe malabsorption could not be explained by the slight mucosal changes occasionally seen by light microscopy with small mucosal inflammation and almost normal villi. However, electron microscopy showed enterocytes with signs of hypofunction and degeneration correlating better to the intestinal malabsorption found in patients with advanced HIV infection and chronic diarrhoea.

Adult↗
PubMed1997

Lipopolysaccharides and beta-glucuronidase activity in choledochal bile in relation to choledocholithiasis.

Common duct gallstones are mainly of the brown pigment type, which are usually attributed to bacterial factors. Bacterial beta-glucuronidase most probably plays a role in the pathogenesis in many but not all patients. The role of other bacterial factors is more undecided. The aims of this study were to investigate a possible association between lipopolysaccharides (LPS) and choledocholithiasis, and to examine the interrelationship to beta-glucuronidase. Common duct bile obtained at endoscopic retrograde cholangiography in 86 patients was assayed for LPS by a limulus amebocyte lysate test, and beta-glucuronidase activity at pH 7.0 was measured. We found that both elevated concentration of LPS and the presence of juxtapapillary duodenal diverticula were associated with common duct stones (p < 0.01, both). Patients who had their common duct stones removed recently had a lower LPS concentration and a lower activity of beta-glucuronidase than those who had a stone in situ (p < 0.01, both), but still higher LPS concentration than those without choledocholithiasis at all (p < 0.01). In multiple logistic regression analysis, elevated LPS was the significant predictor of common duct stones (p < 0.01), and not confounding with neither beta-glucuronidase nor juxtapapillary diverticula. We conclude that gram-negative bacteria convey bacterial factors associated with choledocholithiasis, by mechanisms independent of, and additional to beta-glucuronidase.

Aged↗
PubMed1997

beta-Glucuronidase in common duct bile, methodological aspects, variation of pH optima and relation to gallstones.

beta-Glucuronidase of human or bacterial origin may deconjugate bilirubin diglucuronide, causing pigment gallstones. Intrinsic interference by biliary compounds must be minimized for accurate assay of beta-glucuronidase. We report a modified ion-pair extraction of interfering substances by tetrahexylammonium chloride (THAC) in ethyl acetate in the presence of albumin, and a microtitre plate assay for biliary beta-glucuronidase activity in bile with the substrate p-nitrophenol-glucuronide. Adding albumin improved the recovery of beta-glucuronidase activity to 99.8% (CV 1.9%), and 92.2% of the bilirubin in bile samples was extracted in one step. Competitive inhibition was overcome by increasing the substrate concentration. In endoscopically obtained common duct bile from 44 patients, five different beta-glucuronidase activity peaks were identified, at pH 3.9, 4.8, 5.3, 5.8 and 7.2. The pH profiles were classified into one bacterial pattern and five patterns for presumed human beta-glucuronidase. Of the latter patterns, four displayed dual activity peaks. In a second sample, obtained at follow up in four patients, their original pH profile was maintained. In conclusion, using the modified purification and assay system, we found functionally diverse subcategories of human beta-glucuronidase with respect to activity at variable pH. Our results indicate that several pH optima have to be taken into consideration in order to clarify the role of human biliary beta-glucuronidase in the pathogenesis of pigment gallstones. Bacterial beta-glucuronidase activity was associated with duodenal diverticula (p < 0.05) and common duct stones (p < 0.05).

Adult↗
PubMed1995

Abnormal intestinal motor patterns explain enteric colonization with gram-negative bacilli in late radiation enteropathy.

BACKGROUND & AIMS: Bacterial overgrowth and intestinal pseudo-obstruction may succeed abdominal radiotherapy, and absence of intestinal migrating motor complex (MMC) has been reported in bacterial overgrowth. The aims of this study were to address the relationship between intestinal patterns of motility and gastrointestinal microflora and to elucidate the pathogenesis of late radiation enteropathy. METHODS: Forty-one consecutive female patients with symptoms of late radiation enteropathy were examined by prolonged ambulatory manometry, culture of gastric and duodenal samples with quantification of gram-negative bacilli (GNB) by the glucose gas test, the [14C]D-xylose breath test, and determination of pH and short-chain fatty acids in gastric juice. RESULTS: The intensity of MMC explained 61% (P < 0.001) and 71% (P < 0.001) of the variability of GNB in the stomach and duodenum, respectively, corresponding to the severity of disease. Abnormal MMC index and presence of irregular bursts were the best predictors of GNB (86%; P < 0.001, multiple regression). Fasting gastric pH explained gastric bacterial counts (63%; P < 0.001) but did not predict GNB. CONCLUSIONS: Impaired motility emerges as a causal factor for gastrointestinal colonization with GNB, whereas hypochlorhydria facilitates unspecific gastric colonization. Abnormal motility and GNB in the proximal small intestine are essential factors in the pathogenesis of severe late radiation enteropathy.

Adult↗
PubMed1994

Severe late radiation enteropathy is characterized by impaired motility of proximal small intestine.

Late radiation enteropathy (LRE) is a serious disorder, and therapeutic progress has thus far been hampered by insufficient understanding of the pathogenesis. This prospective study addresses whether alterations in proximal intestinal motility can predict the clinical severity of this disorder. Forty-one consecutive patients with chronic abdominal complaints after radiotherapy for gynecological cancer were examined by prolonged ambulatory manometry. Twenty-seven healthy adults served as controls. Impaired fasting motility was found in 12 of 41 patients (29%), and attenuated postprandial motor response after a liquid-solid meal was seen in 10 of 41 patients (24%). Postprandial delay of the migrating motor complex (MMC) was a good predictor of the degree of malnutrition (Cox regression, P < 0.01), and intensity of the MMC and postprandial motility index explained 69% (P < 0.001, multiple regression) of the variability in degree of malnutrition, assessed by weight loss and serum albumin level. The typical presentation of severe LRE was clinical symptoms suggesting intestinal pseudoobstruction, malnutrition, failure of a liquid-solid meal to induce postprandial motility, and delayed initiation and reduced intensity of MMC during nocturnal fasting. Prolonged ambulatory manometry was useful for detection of dysmotility in patients with symptoms of LRE and impaired motility of proximal small intestine seems to be a key factor in the pathogenesis of severe LRE.

Adult↗
PubMed1994

Common bile duct stones are mainly brown and associated with duodenal diverticula.

This study investigated the composition of common duct gall stones from 61 patients, aged 49-94. The stones were collected endoscopically with a dormia basket after endoscopic papillotomy. The cholesterol content was measured both by infrared spectroscopy (mean 29%, range 0-99%) and enzymatically (mean 23%, range 0-96%). The results of the two measurements showed good correlation (r2 = 0.92), indicating that cholesterol can be adequately measured enzymatically. Most of the stones were pigment stones. When examined by infrared spectroscopy, 44 stones (72%) contained less than 50% cholesterol (mean 4%, range 0-23%). The bilirubinate content in these stones was 56%, range 12-100%. Forty two of these stones were brown stones, and only two were black stones. Pigment stones were associated with juxtapapillary diverticula (p < 0.01). It was found that brown pigment stones were the commonest symptomatic bile duct calculi in the patients studied, who are representative of a Western population.

Aged↗
PubMed1993

Urinary D-glucaric acid, a marker substance for microsomal enzyme induction. Methodological aspects, responses to alcohol and findings in workers exposed to toluene.

D-glucaric acid, an end product of glucuronic acid metabolism, has been used as a marker substance for microsomal enzyme induction. In this study a convenient microtitre-plate based method for the quantification of urinary D-glucaric acid has been developed and validated. Mean urinary D-glucaric acid excretion in 20 health humans as measured by this method was 3.2 mumol glucaric acid mmol-1 creatinine, 95% confidence interval 3.0-3.4. Moderate alcohol consumption in 18 healthy volunteers did not significantly augment the urinary D-glucaric acid excretion. Occupational exposition to toluene in a printing plant was investigated. In spite of considerable intra- and inter-individual variability, a significant difference between exposed (3.5, 3.1-3.9) and non-exposed (2.6, 2.2-3.0) workers was observed, p < 0.025. We conclude that the measurement of D-glucaric acid can be utilized for biological screening of enzyme induction on a group basis.

Adult↗
PubMed1993

Total protein in common duct bile measured by acetonitrile precipitation and a micro bicinchoninic acid (BCA) method.

Bile protein assays are complicated due to interference by other bile substances. In the present study we describe a microtiter plate method for the purification and quantification of bile proteins. The method is based on addition of acetonitrile in three steps to reconstituted freeze-dried bile, followed by ethanol washing of the precipitated proteins. Finally, protein in the precipitate is quantitated by two-point colour development using micro BCA reagents. Overall recoveries of protein in reconstituted bile spiked with exogenous protein (Seronorm) ranged from 91.0% (coefficient of variation; CV = 7.0%) to 97.1% (CV = 2.4%) by recoveries of 125I-Fibrinogen and 125I-Albumin. Bile pigments were largely removed during precipitation and washing, as verified by high pressure liquid chromatography (HPLC). Preferably the samples should be freeze-dried initially, as this lowered the blank readings. Two-point colour development with the BCA reagents were identical for standards assayed directly and standards added to protein depleted bile, and processed through all steps. Hence, no interference by either residual bile constituents nor the reagents upon the BCA protein assay could be detected. Standard curves ranged from 0.05 to 5.0 gl-1 (r > 0.98). Within day reproducibility (n = 15) was 7.8% (CV) and day to day (n = 10) was 12.1% (CV). Mean protein concentration in common duct bile from 30 patients was 1.20 gl-1 (range 0.34-3.87 gl-1). The method appears suitable for assay of bile protein, requires only limited sample volumes and allows processing of many samples within a short time.

Acetonitriles↗
PubMed1992

Fasting hypochlorhydria with gram positive gastric flora is highly prevalent in healthy old people.

Fifteen healthy old people mean age 84 years (range 80-91 years), were examined to assess the effect of advanced age on the microecology of the upper gastrointestinal tract. Twelve of 15 (80%) were hypochlorhydric with pH 6.6 (0.3) (mean (SEM) and a mean bacterial count of 10(8) colony forming units (CFU) per ml (range 10(5)-10(10)) in fasting gastric aspirate. Normochlorhydric subjects had low counts (< or = 10(1) CFU/ml). The microbial flora was dominated by viridans streptococci, coagulase negative staphylococci, and Haemophilus sp. Only one subject harboured significant concentrations of Gram negative bacilli with Escherichia coli (10(4-5) CFU/ml) and Klebsiella (10(4-5)). Strict anaerobes were not found. The total concentration of short chain fatty acids in gastric aspirate was 10.6 (2.9) mmol/l (mean (SEM). Absence of significant, intraluminal fermentation of xylose to CO2 was shown by the 14C-d Xylose breath test, and ambulatory manometry showed preserved fasting motility pattern of the small intestine. Serum immunoglobulins were normal. Advanced age is accompanied by fasting hypochlorhydria and colonisation with mainly Gram positive flora in the upper gut. Other factors than old age and fasting hypochlorhydria are required for colonisation with Gram negative bacilli.

Achlorhydria↗
PubMed1992

Quantification of lipopolysaccharides in human bile with or without gram-negative bacteria.

Lipopolysaccharide (LPS) was assayed in 78 samples of human common-duct bile, obtained at endoscopic retrograde cholangiography. The LPS was assayed by a chromogenic limulus amebocyte lysate (LAL) test, after dilution of bile samples in heparinized plasma and inactivation of inhibitors. The assay was not influenced by other biliary constituents, as demonstrated by the recovery of standards. Bile pigments did not influence the results. The LAL test was positive in 60 of the samples, 59 of which had a positive culture for gram-negative bacteria or Candida sp. The levels of LPS were significantly correlated to the total number of bacteria (n = 16, R = 0.55, p less than 0.05). The median LPS level was 35,250 ng/l and showed a very large variation (140 ng/l to 27.8 mg/l). In four of the samples gram-negative bacteria were present, but no LPS could be detected. The study demonstrates the presence of LPS in great quantities in human bile and supports the feasibility of using the LAL test on bile samples. The presence of LPS (within the detection limit) appears to be associated with local microbial colonization.

Adult↗
PubMed1990

Digital ambulatory manometry of the small intestine in healthy adults. Estimates of variation within and between individuals and statistical management of incomplete MMC periods.

A new technique for ambulatory manometry of the small intestine with digital storage of signals is presented. Postprandial motility after a 1700-kJ meal and nighttime fasting motility were recorded in 19 healthy young adults. A comprehensive statistical approach was worked out to illuminate the statistical properties of fasting motility data from long-term studies. Separate quantifications of the variation within and between individuals are presented for the migrating motor complex (MMC). The overall mean for the MMC period was 107 min, with incomplete periods included as censored data. Standard deviation within individuals was 49 min, and standard deviation between individuals 16 min. Presented in the same manner, phase III in the proximal jejunum lasted 5.3 min, with standard deviations of 1.5 and 1.1 min, respectively. The propagation velocity of phase III in the distal duodenum was 10.8 cm/min, with standard deviations of 3.7 and 4.1 cm/min, respectively. Fed-state lasted 324 +/- 110 min (mean +/- SD), and adjusted fed-state, an alternative definition proposed in this study, 290 +/- 80 min. This variance component model, extended to handle censored data, provides a useful statistical approach for the analyses of the MMC. The MMC period proved to be less suitable for quantitative comparisons because of dominating intraindividual variance. Comparisons presented indicate that discrepancies in reference values depend, to a great extent, on the statistical methods applied.

Adult↗
PubMed1990

HPLC separation and quantification of bilirubin and its glucuronide conjugates in faeces and intestinal contents of germ-free rats.

We describe an accurate reverse-phase high-performance liquid chromatography (HPLC) method for the separation and quantification of unconjugated bilirubin (UCB) and its monoglucuronide (BMG) and diglucuronide (BDG) conjugates in faeces and intestinal contents from germ-free (GF) rats. We demonstrated that female GF rats excreted predominantly BMG and that the percentage of this conjugate was at most 71.7% of the total bilirubin excreted with the faeces. The highest percentages for BDG and the UCB were 27.9% and 6.0%, respectively. The bile pigment composition in duodenal contents was 59.8% BDG and 40.2% BMG (median percentage) and was 47.7% BDG, 50.1% BMG and 2.2% UCB in ileal contents. Deconjugation of BDG to BMG was profound in caecal contents with 26.0% BDG, 67.4% BMG and 6.6% UCB. Endogenous (mammalian) beta-glucuronidase activity was present in intestinal contents throughout the entire length of the intestine and in faeces of the GF rats. The results indicated that it is very likely that endogenous beta-glucuronidase plays a role in the deconjugation of bilirubin glucuronides as well as of other glucuronides in the intestine of the GF rat.

Animals↗