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Biomedical subjects

A Danielsson

Publications and source records attributed to A Danielsson.

At least 55 records · Page 3Linked to original sources
PubMed1998

Mechanisms of diarrhoea in myotonic dystrophy.

BACKGROUND: Gastrointestinal (GI) symptoms are common in myotonic dystrophy (MD). Diarrhoea is one of the more disabling of these GI complaints. The mechanisms behind diarrhoea in MD have not previously been investigated systematically. OBJECTIVE: To elucidate the mechanisms behind diarrhoea in MD. METHODS: Twenty patients with MD and suffering from diarrhoea were investigated in order to detect malabsorption (blood tests and faecal fat excretion) and bile acid malabsorption ([75Se]selenahomocholic acid-taurine (SeHCAT) retention) and to study intestinal morphology (duodenal and rectal biopsies). RESULTS: Two patients had deficiency of folic acid and four showed reduced levels of pancreatic isoamylase, but none of them had steatorrhoea. Two out of eight patients had abnormal bile acid breath tests with normal SeHCAT, indicating small bowel bacterial overgrowth and 12 displayed reduced SeHCAT retention. Duodenal biopsies were normal in eight patients and five out of nine rectal biopsies displayed slight inflammation. CONCLUSIONS: A possible mechanism of diarrhoea in MD could be identified in most of the patients. Bile acid malabsorption seems to be a frequent cause and can be treated successfully.

Adult↗
PubMed1997

Effects of vitamins E, C and catalase on bromobenzene- and hydrogen peroxide-induced intracellular oxidation and DNA single-strand breakage in Hep G2 cells.

BACKGROUND/AIMS: Water-soluble vitamin E (Trolox C), ascorbic acid and catalase were shown in our previous study to protect isolated rat hepatocytes against bromobenzene-induced toxicity. METHODS: In order to study the mechanisms of this protection and the pathogenesis of bromobenzene-induced hepatocellular injury, a fluorometric assay for the investigation of intracellular oxidation, indicated by conversion of dichlorofluorescein diacetate to dichlorofluorescein, was used. Single-strand DNA breakage was also evaluated in Hep G2 cells by a radio-labelling method. RESULTS: Bromobenzene (2.4 and 4.8 mM) induced a significant increase in dichlorofluorescein fluorescence intensity compared to the controls. Trolox C, ascorbic acid or catalase significantly inhibited bromobenzene-induced enhancement of fluorescence intensity (p<0.05-0.001), as well as reduced auto-intracellular oxidation in untreated Hep G2 cells. Hydrogen peroxide (H2O2) evoked a dose-dependent increase in dichlorofluorescein fluorescence intensity in Hep G2 cells, and the effect was completely blocked by Trolox C (2.0 mM) and catalase (4800 unit/ml). Bromobenzene caused significant single-strand DNA breakage in Hep G2 cells during 2 h suspension incubation and 24 h primary incubation. H2O2 (400 microM) led to marked single-strand DNA breakage in 20 min, and the effect was attenuated by Trolox C. CONCLUSIONS: Metabolism of bromobenzene in Hep G2 cells induces production of H2O2, indicated by enhancement of dichlorofluorescein fluorescence intensity, or other free radicals, which leads to single-strand DNA breakage in the cells. Vitamins E and C and catalase display strong intracellular antioxidative effects. Vitamin E could partially inhibit H2O2-induced single-strand DNA breakage in the cells.

Antioxidants↗
PubMed1997

A critical evaluation of ultrasound measurement of inferior vena cava diameter in assessing dry weight in normotensive and hypertensive hemodialysis patients.

The utility of measurement of the inferior vena cava diameter (IVCD) with ultrasound for the assessment of fluid status and posthemodialysis dry weight was studied in 35 hemodialysis (HD) patients, 17 with and 18 without hypertension. In 17 patients (group A), IVCD was measured before and 35 to 40 minutes after HD, pre-HD blood volume (BV) was measured with radiolabeled albumin and post-HD BV was calculated from the change in hematocrit. In 18 patients (group B), IVCD was measured repeatedly during HD and 2 hours after HD. Changes in BV were recorded by monitoring of the hematocrit "on line." Body weight, blood pressure (BP), BV, and IVCD decreased in the entire population. In group A, BV was significantly larger in the hypertensive patients than in the normotensive patients, and it was correlated with the mean BP before and after HD. In the whole population, IVCD was larger in the hypertensive than in the normotensive patients before and after HD. These results confirm that extracellular fluid overload plays an important role in the pathogenesis of dialysis-associated hypertension. In group B, BV and IVCD decreased in parallel during HD and increased during 2 hours after HD due to refilling of the intravascular space, indicating that changes in IVCD reflect changes in BV. In 8 patients studied twice, IVCD increased much more after a 3-hour HD session than after a 6-hour session. At the end of HD, several patients had IVCD below the reference range but IVCD increased during the following 1 to 2 hours, in some patients to values above the reference range. IVCD measured at the end or shortly after HD may therefore be misleading in assessing dry weight.

Blood Volume↗
PubMed1997

An adaptation of hydrophobic interaction chromatography for estimation of protein solubility optima.

This study describes an adaptation of hydrophobic interaction chromatography (HIC) that can be used to estimate protein solubility optima. The method does not support determination of absolute, e.g. quantitative solubility, however it does provide a basis for identifying the salt concentration, pH, or additive concentrations that support the highest relative solubility. The magnitude of a given salt's effects are consistent with its ranking in the Hofmeister series. IgG in solutions of strong 'precipitating' salts exhibits a classical salting-in/salting-out curve, described by a solubility minimum at low ionic strength, increasing to a well-defined maximum, and then losing solubility with further elevation of salt concentration. The direct effect of pH on protein solubility, as well as its indirect effect via modification of the ionic equilibria of dissolved salts, can also be tracked. Cooperative effects of solubility modifiers such as amino acids can likewise be assessed. The technique can be a useful tool in the development of liquid formulations for protein pharmaceuticals.

Chemistry, Pharmaceutical↗
PubMed1997

Colonic endocrine cells in inflammatory bowel disease.

OBJECTIVES: To study colonic endocrine cell types in patients with ulcerative colitis (UC) and Crohn's disease (CD). SETTING: Departments of Medicine and Pathology, University Hospitals, Umeå and Uppsala, Sweden. SUBJECTS: Seventeen patients with UC (seven females and 10 males) and 11 patients with CD (five females and six males). Twenty-two patients (eight females and 14 males) operated on for colon carcinoma and without signs of inflammatory bowel disease were used as controls. MEASUREMENTS: The colonic endocrine cell types were identified by immunohistochemical methods and quantified by computed image analysis. RESULTS: The areas of the argyrophil cells as well as those immunoreactive to chromogranin A and serotonin were significantly increased in patients with both UC and CD, compared with those in the controls. In patients with CD, the areas of polypeptide YY(PYY)- and pancreatic polypeptide (PP)-immunoreactive cells were significantly reduced, whilst the area of enteroglucagon-immunoreactive cells was increased. There was no statistical difference in endocrine cell area between specimens with slight versus severe inflammation, except for PYY and enteroglucagon cell areas in patients with CD. Whilst the former cell area decreased, the latter increased in specimens with severe inflammation. The mean cellular area for each endocrine cell type did not differ between the controls and patients with UC or CD. CONCLUSIONS: The increase in the serotonin-immunoreactive cell area in patients with both UC and CD might be one of the factors causing reduced colonic contraction and increased intraluminal pressure observed in patients with inflammatory bowel disease. Furthermore, in patients with CD, the decreased PYY-immunoreactive cell area may explain the decreased absorption and increased secretion found in these patients.

Adolescent↗
PubMed1997

Serum immunoreactive leptin concentration and its relation to the body fat content in chronic renal failure.

Leptin, secreted from fat cells, functions as a lipostat mechanism through modulation of satiety signals. The role of leptin in humans has been only partly revealed. However, obese patients have markedly elevated levels of this hormone, and in both normal-weight and obese subjects there is a direct correlation between serum leptin levels and the percentage of body fat. The aim of the present study was to investigate the role of leptin and its relation to body fat content in chronic renal failure (CRF), a disorder associated with decreased appetite. Serum leptin levels and body composition (dual-energy x-ray absorptiometry) were measured in a cohort of 59 patients with terminal CRF (creatinine clearance rate, 8 +/- 1 ml/min). Sixteen of the patients were re-evaluated after 12 mo of peritoneal dialysis treatment, and eight patients were re-evaluated after 12 mo of hemodialysis treatment. The mean serum leptin concentrations were markedly higher (mean +/- SEM) in patients with CRF than in healthy control subjects matched for gender and body mass index (25.7 +/- 5.2 ng/ml versus 8.4 +/- 0.9 ng/ml; P < 0.001). Patients with ongoing signs of inflammation (C-reactive protein > 10 mg/L) demonstrated higher serum leptin levels (41.9 +/- 13.7 ng/ml versus 18.6 +/- 4.2 ng/ml; P < 0.05) than patients with normal C-reactive protein. A strong positive correlation (rho = 0.83; P < 0.0001) was found between serum leptin concentrations and the percentage of body fat. After 12 mo of peritoneal dialysis, the amount of body fat increased markedly (19.0 +/- 1.5 to 25.1 +/- 2.2 kg; P < 0.001), and the changes in serum leptin concentrations correlated significantly (rho = 0.69; P < 0.01) to the changes in the body fat content. In contrast, no significant changes in either body fat content or serum leptin levels were recorded in the eight patients that were re-evaluated after 12 mo of hemodialysis. Serum leptin concentrations are approximately three times higher in patients with CRF compared with healthy control subjects with a similar body mass index. In this study, it is also demonstrated that serum leptin is a good marker for the body fat content in CRF patients and correlates strongly to changes in body fat during 12 mo of peritoneal dialysis. These findings suggest that serum leptin could serve as a valuable clinical marker for the body fat content in patients with CRF. Further studies are needed to verify the hypothesis that increased serum leptin concentrations may contribute to uremic anorexia.

Adipose Tissue↗
PubMed1996

A new simple and rapid screening method for variant transthyretin-related amyloidosis.

To screen for transthyretin (TTR) related amyloidosis rapidly and reliably, we have developed a new method using a centrifugal concentrator device and electrospray ionization mass spectrometry (ESI-MS). Only 50 microliters of serum is needed for the analysis. After preparation of the samples with anti-TTR antibody they were passed through a 1000 kDa cut off centrifugal concentrator which retained the antibody. By analyzing the obtained filtrate with ESI-MS, variant forms of TTR was detected. TTR (Met30), with a molecular weight 32.0 Da higher than the normal form of TTR, was found in all FAP patients examined. In 3 liver transplanted FAP patients, the abnormal peaks had disappeared. In conclusion, The TTR Met30 mutation was easily detected in serum samples by electrospray ionization mass spectrometry after centrifugal concentration. The proposed method is simple to perform, as no HPLC is required, and offers a possibility to screen populations for TTR related amyloidosis.

Adult↗
PubMed1996

Impact of gastrointestinal dysfunction on survival after liver transplantation for familial amyloidotic polyneuropathy.

Liver transplantation is the only effective treatment of familial amyloidotic polyneuropathy type I (FAP). The aim of the present investigation was to identify factors at the time of submission for transplantation that had impact on survival, with special reference to gastrointestinal disturbances. All 28 liver-transplanted FAP patients evaluated at Umeå University Hospital were included in the study. A modified body mass index was used to assess nutritional status. Intestinal examinations were performed to diagnose bile acid malabsorption, gastric retention, and bacterial contamination of the small bowel. A significantly improved survival rate was found for patients in a good nutritional state (P = 0.002). Peripheral neurological symptoms were unrelated to survival, whereas increased mortality was found for patients with bile acid malabsorption (P < 0.05). Bacterial contamination and gastric retention were common complications of the disease. In conclusion, malabsorption and malnutrition have a profound impact on the outcome of liver transplantation for familial amyloidotic polyneuropathy.

Adult↗
PubMed1996

A genetic analysis of the role of calcineurin and calmodulin in Ca++-dependent improvement of NaCl tolerance of Saccharomyces cerevisiae.

Mutants of Saccharomyces cerevisiae lacking activity of the Ca2+/calmodulin-dependent protein phosphatase calcineurin, show sensitivity to high concentrations of sodium that is partly reversed by the external supply of Ca2+. On long-time exposure to NaCl stress the mutants display an increased intracellular Na+/K+ ratio which is partially corrected by the addition of Ca2+, improving the sodium efflux of not only calcineurin-defective cells but also wild-type cells. We also demonstrate that the NaCl sensitivity of cmd mutants, expressing modified forms of calmodulin that do not bind Ca2+, is strongly reversed by the addition of Ca2+. This effect is highly dependent on calcineurin, since the NaCl tolerance of a cmd1-3 strain, carrying an additional mutation in calcineurin, is only slightly assisted by Ca2+. A striking characteristic of the loss of function of calcineurin is a several-fold increased content of intracellular Ca2+, localized mainly in subcellular compartment(s). If the compartmentalized Ca2+ pool is brought back to normal levels by an additional inactivating mutation of the vacuolar Ca2+-transporting ATPase, such double mutants do not significantly improve their tolerance to NaCl.

Calcineurin↗
PubMed1996

Lysosomal enzyme activities in gallbladder mucosa of gallstone-free subjects and patients with gallstones.

BACKGROUND/AIMS: Gallstone patients have a reduced cellular lysosome content in the gallbladder mucosa cells compared with gallstone-free subjects. The purpose of the study was to further evaluate the possible role of lysosomes in the pathogenesis of cholesterol gallstone formation in humans. METHODS: Lysosomal enzyme activities were assayed in gallbladder mucosa and for comparison in liver specimens of 19 gallstone-free subjects and 24 gallstone patients undergoing cholecystectomy. RESULTS: Gallstone patients had 25-50% lower activities of the lysosomal proteases cathepsin B, D and L in their gallbladder mucosa compared with gallstone-free subjects. The activity of acid phosphatase also tended to be decreased in gallstone patients. The liver lysosomal enzyme activities were not significantly different between the two groups. CONCLUSIONS: The results show that gallstone patients have diminished lysosomal enzyme activities in the gallbladder mucosa, a finding which may be related to decreased intracellular degradation of proteins and/or mucin in the mucosal cells. This may lead to a higher concentration of mucin in gallbladder bile and thus an increased risk of precipitation of cholesterol crystals and gallstone formation.

Acid Phosphatase↗
PubMed1996

Oral budesonide versus prednisolone in patients with active extensive and left-sided ulcerative colitis.

BACKGROUND & AIMS: Systemic glucocorticosteroids (GCSs) have proven efficacy in active ulcerative colitis but cause undesired systemic side effects. Therefore, new GCSs with high topical activity and a high rate of metabolism may be of clinical value in this condition. The aim of this study was to explore the efficacy and safety of the topically acting GCS budesonide in an oral controlled-release formulation in extensive or left-sided, mild to moderately active ulcerative colitis. METHODS: A 9-week, randomized, double-blind, controlled trial was performed, and treatments with 10 mg budesonide or 40 mg prednisolone daily, both gradually tapered, were compared. Endoscopic improvement and effect on endogenous plasma cortisol were assessed. RESULTS: Thirty-four patients were administered budesonide, and 38 patients were administered prednisolone. Mean endoscopic scores improved significantly in both groups but without difference between the groups. Five patients in the budesonide group and 7 patients in the prednisolone group deteriorated and were withdrawn from the study. Morning plasma cortisol levels were suppressed in the prednisolone group (entry, 449 nmol/L; 2 weeks, 116 nmol/L; 4 weeks, 195 nmol/L) but were unchanged in the budesonide group. CONCLUSIONS: The GCS budesonide administered in an oral controlled-release formulation seems to give an overall treatment result in active ulcerative colitis approaching that of prednisolone but without suppression of plasma cortisol levels. This concept merits further evaluation.

Administration, Oral↗
PubMed1996

Protective effect of S-adenosyl-L-methionine on bromobenzene- and D-galactosamine-induced toxicity to isolated rat hepatocytes.

The protective effect of S-adenosyl-L-methionine (SAMe) on bromobenzene (BB)- or D-galactosamine (GalN)-induced damage to isolated rat hepatocytes and its effect on cellular glutathione (GSH) levels were investigated. SAMe at concentrations of 0.5 to 3.0 mmol/L significantly reduced lactate dehydrogenase leakage from cells exposed to 1.6 mmol/L BB (P < .05 to .001) during 2 hours' incubation. GalN at 25 to 50 mmol/L induced a marked increase of LDH leakage from the cells during the later stage of 24 hours' incubation and SAMe at 1.0 mmol/L clearly attenuated the LDH leakage in GalN (25 mmol/L)-exposed cells. The GSH content in the cells exposed to 2.4 mmol/L BB for 150 minutes was markedly decreased, and further decreased during 24 hours' incubation. SAMe (1.5 mmol/L) both reduced LDH leakage and corrected GSH depletion in cells exposed to 2.4 mmol/L BB. The GSH content in 25 and 50 mmol/L GalN-exposed cells was strikingly diminished to 51.2% and 32.8% of the controls, respectively, during 24 hours' of exposure. SAMe at 1.5 mmol/L significantly reduced the loss in GSH content in 25 mmol/L GalN-exposed cells. The findings show that SAMe has beneficial effects on both BB- and GalN-induced toxicity to rat hepatocytes. The main mechanism behind the protective effect of SAMe on BB and GalN toxicity seems to be associated with enhancement of GSH synthesis in the cells.

Animals↗
PubMed1996

Natural history and prognostic factors in 305 Swedish patients with primary sclerosing cholangitis.

BACKGROUND/AIMS--The course of primary sclerosing cholangitis (PSC) is highly variable and unpredictable. This study describes the natural history and outcome of PSC. These data were used to construct a prognostic model for patients with PSC. METHODS--A total of 305 Swedish patients with PSC were studied. The median follow up time was 63 (1-194) months and all patients could be traced for follow up. Some 79 patients died or had a liver transplant. The prognostic significance of clinical, biochemical, and histological findings at the time of diagnosis were evaluated using multivariate analysis. RESULTS--The estimated median survival from time of diagnosis to death or liver transplantation was 12 years. Cholangiocarcinoma was found in 24 (8%) of the patients and 134 (44%) of the patients were asymptomatic at the time of diagnosis. The estimated survival rate was significantly higher in the asymptomatic group (p < 0.001). However, 29 (22%) of the asymptomatic patients became symptomatic during the study period. It was found that age, serum bilirubin concentration, and histological stage at the time of diagnosis were independent predictors of a bad prognosis. These variables were used to construct a prognostic model. CONCLUSIONS--This prognostic model developed from a large homogeneous population of PSC patients should be of value for the timing of transplantation and patient counselling in PSC.

Adolescent↗
PubMed1996

Budesonide prolongs time to relapse in ileal and ileocaecal Crohn's disease. A placebo controlled one year study.

BACKGROUND AND AIMS: To evaluate the efficacy and safety of the topical corticosteroid budesonide, given in an oral controlled release formulation for maintenance of remission in patients with ileal and ileocaecal Crohn's disease (CD). PATIENTS AND METHODS: Out of 176 patients with active CD who had achieved remission (CD activity index score < or = 150) after 10 weeks' treatment with either budesonide or prednisolone, 90 were randomised to continue with once daily treatment of 6 mg budesonide, or 3 mg budesonide or placebo for up to 12 months in a double blind, multicentre trial. Time to symptomatic relapse was calculated using Kaplan-Meier estimates. Morning plasma cortisol was measured at clinic visits and a corticotropin stimulation test was performed after three months of treatment. RESULTS: Thirty two patients were allocated to the 6 mg budesonide group, 31 to the 3 mg group, and 27 to the placebo group. After three months, 19 per cent of the patients in the 6 mg group had relapsed, compared with 45 per cent in the 3 mg group and 44 per cent in the placebo group (p = 0.047). The corresponding results after 12 months was 59 per cent in the 6 mg budesonide group, 74 per cent in the 3 mg group, and 63 per cent in the placebo group (p = 0.44). The median time to relapse or discontinuation was 258 days in the 6 mg group, 139 days in the 3 mg group, and 92 days in the placebo group (p = 0.021). Mean morning plasma cortisol values increased from entry in all three groups with no statistically significant differences at 12 months. All 13 patients remaining in the placebo group after three months had a normal corticotropin stimulation response, compared with 18 of 23 patients in the 6 mg, and 19 of 21 in the 3 mg budesonide groups (p = 0.14). Acne and moon face were slightly more common in the budesonide groups. CONCLUSION: 6 mg budesonide once daily is significantly more efficacious than placebo in prolonging time to relapse in CD, and causes only minor systemic side effects.

Administration, Oral↗