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Biomedical subjects

E Berg

Publications and source records attributed to E Berg.

At least 19 recordsLinked to original sources
PubMed2000

Safety and efficacy of dynamic graciloplasty for fecal incontinence: report of a prospective, multicenter trial. Dynamic Graciloplasty Therapy Study Group.

PURPOSE: Dynamic graciloplasty has been used for intractable fecal incontinence, and good results have been reported. The aim of this study was to assess prospectively the safety and efficacy of dynamic graciloplasty for intractable fecal incontinence in a prospective, multicenter trial. METHODS: A total of 123 adults were treated with dynamic graciloplasty at 20 institutions. Continence was assessed preoperatively and postoperatively by use of 14-day diaries. RESULTS: There was one treatment-related death. One hundred eighty-nine adverse events occurred in 91 patients (74 percent). Forty-nine patients (40 percent) required one or more operations to treat complications. One hundred seventy (90 percent) events were resolved. Sixty-three percent of patients without pre-existing stomas recorded a 50 percent or greater decrease in incontinent events 12 months after dynamic graciloplasty, and an additional 11 percent experienced lesser degrees of improvement. Twenty-six percent were not improved, worsened, or exited. In patients with pre-existing stomas, 33 percent achieved successful outcomes at 12 months. This number increased to 60 percent at 18 months. Seventy-eight percent of patients had increased enema retention time, and mean anal canal pressures improved significantly at 12 months. Significant changes in quality of life were also observed. CONCLUSIONS: Objective improvement can be demonstrated in the majority of patients with end-stage fecal incontinence treated with dynamic graciloplasty. Reduction in incontinence episodes can be correlated with improved quality of life. Adverse events are frequently encountered, but most resolve with treatment.

Adolescent↗
PubMed2000

Reliability and validity of the Dental Indifference Scale in a population of 18-year-olds in Norway.

OBJECTIVES: The aims of this study were to estimate the reliability and validity of the Dental Indifference Scale (DIS) (Nuttall, 1996) in a population of 18-yr-olds in Norway. METHODS: The DIS-scale was mailed to a sample of 1119 18-yr-olds in two Norwegian counties. Nearly 87% completed the questionnaire and consented to the collection of data from their dental records. Ten percent of the sample, drawn at random, was asked to complete the questionnaire a second time, after a time delay of 15 weeks (response rate 83%). The reliability estimation of the sum-scores of DIS was based on Pearson's correlation between test-retest scores and internal consistency (Cronbach's alpha). The frequency of missed appointments from age 12, recorded in the dental treatment records, was used as the validating criterion. The validity was analyzed by Pearson's correlation, and step-wise multiple regression. RESULTS: The correlation coefficient (Pearson) for the test-retest comparison was 0.43. The correlation coefficient between the DIS-scores and the frequencies of missed dental appointments was 0.24. The Cronbach's Alpha coefficient for the eight DIS-questions was 0.35 (n=868). Only two of the eight DIS-questions entered the stepwise regression model and explained 15% of the variance of the frequency of missed appointments. CONCLUSIONS: The Dental Indifference Scale (DIS) was found to have a low reliability and validity in this study population, and it is recommended that it should not be used without further investigation. It may be necessary to design an alternative instrument if further work into the hypothesized trait of dental indifference is to be undertaken.

Adolescent↗
PubMed2000

Factors related to missed and cancelled dental appointments among adolescents in Norway.

The aim of this study was to explore possible explanatory factors related to high frequency of missed/cancelled dental appointments during the age group 12-18 yr. A total of 754 20 yr olds completed a questionnaire including variables measuring demographics, occupation (school/job), attendance pattern, attitudes to dentists, opinion about importance of dental treatment, and the psychometric scales Dental Fear Scale (DFS), Dental Beliefs Survey (DBS) and Geer Fear Scale (GFS). Based on written consents, the following data were recorded from their dental records: the total number of scheduled appointments, the number of missed and cancelled appointments and the individual caries experience of those in the age group 12-18 yr. A total of 124 subjects who had missed/cancelled 20% or more of their dental appointments during this age were defined as a target group. A stepwise regression model indicated that the likelihood of being included in the target group increased by a factor of 6.0 if the subject had forgotten dental appointments during the last 5 yr, by a factor of 3.5 for working or without specified occupation (as opposed to attending school), by a factor of 2.7 for negative beliefs of dentists, and by a factor of 2.1 for high caries experience.

Adolescent↗
PubMed2000

Conduction defects after coronary artery bypass grafting--a disappearing problem?

BACKGROUND AND AIMS: To evaluate the incidence of conduction defects (CDs) following coronary artery bypass grafting (CABG) in three different patient populations, to assess the etiologic factors associated with CDs, and to find out their effect on immediate postoperative outcome of the patient. MATERIAL AND METHODS: Three patient populations were prospectively studied: cohort A consisted of 180 CABG-patients operated between 1990-91, cohort B of 100 patients operated during the year 1993 and cohort C of 118 patients operated from April 1997 to June 1997. Cold crystalloid cardioplegia was used throughout the study years. In the first cohort A, two separate cavae were cannulated and clamped, venting through the right upper pulmonary vein was used, iced cold saline was used in pericardium, and cardioplegia was given until a myocardial temperature of 10-15 degrees of Celcius was attained. In the two later cohorts, two-stage venous cannula and aortic root venting were used and cardioplegia was given only until the activity of the myocardium stopped. Proximal anastomoses were performed after aortic declamping in cohort A, and during aortic occlusion in the two later cohorts. RESULTS: The incidence of permanent CDs in cohort A was 36%, in cohort B 5% and in cohort C 1%. Permanent atrioventricular (AV-) and left-sided blocks disappeared first. Left main coronary artery stenosis and low myocardial temperatures were associated with CDs. Patients with permanent CDs had more often low cardiac output after the operation, their values of cardiac enzymes were higher, and they had more often postoperative infarction than patients without CDs. CONCLUSIONS: The disappearance of all long lasting AV- and left-sided blocks simultaneously with decreasing plasma levels of cardiac enzymes is evidence that protection of both conduction tissue and myocardium had considerably improved in the two later cohorts. Giving cardioplegia in smaller amounts and more often at the same time when raising the general temperature during perfusion were the main reasons for the disappearance of postoperative CDs.

Arrhythmias, Cardiac↗
PubMed1999

Epitope mapping of CCR5 reveals multiple conformational states and distinct but overlapping structures involved in chemokine and coreceptor function.

The chemokine receptor CCR5 is the major coreceptor for R5 human immunodeficiency virus type-1 strains. We mapped the epitope specificities of 18 CCR5 monoclonal antibodies (mAbs) to identify domains of CCR5 required for chemokine binding, gp120 binding, and for inducing conformational changes in Env that lead to membrane fusion. We identified mAbs that bound to N-terminal epitopes, extracellular loop 2 (ECL2) epitopes, and multidomain (MD) epitopes composed of more than one single extracellular domain. N-terminal mAbs recognized specific residues that span the first 13 amino acids of CCR5, while nearly all ECL2 mAbs recognized residues Tyr-184 to Phe-189. In addition, all MD epitopes involved ECL2, including at least residues Lys-171 and Glu-172. We found that ECL2-specific mAbs were more efficient than NH2- or MD-antibodies in blocking RANTES or MIP-1beta binding. By contrast, N-terminal mAbs blocked gp120-CCR5 binding more effectively than ECL2 mAbs. Surprisingly, ECL2 mAbs were more potent inhibitors of viral infection than N-terminal mAbs. Thus, the ability to block virus infection did not correlate with the ability to block gp120 binding. Together, these results imply that chemokines and Env bind to distinct but overlapping sites in CCR5, and suggest that the N-terminal domain of CCR5 is more important for gp120 binding while the extracellular loops are more important for inducing conformational changes in Env that lead to membrane fusion and virus infection. Measurements of individual antibody affinities coupled with kinetic analysis of equilibrium binding states also suggested that there are multiple conformational states of CCR5. A previously described mAb, 2D7, was unique in its ability to effectively block both chemokine and Env binding as well as coreceptor activity. 2D7 bound to a unique antigenic determinant in the first half of ECL2 and recognized a far greater proportion of cell surface CCR5 molecules than the other mAbs examined. Thus, the epitope recognized by 2D7 may represent a particularly attractive target for CCR5 antagonists.

Amino Acid Sequence↗
PubMed1999

Dental anxiety and dental avoidance among 12 to 18 year olds in Norway.

The aim of this study was to explore the prevalence and possible explanatory factors of dental avoidance due to dental anxiety among 12 to 18 year olds treated within the Norwegian Public Dental Service. A total of 754 20-yr-olds completed a questionnaire and three psychometric scales, the Dental Fear Scale (DFS), the Dental Beliefs Survey (DBS) and the Geer Fear Scale (GFS), and gave their consent to collect data from their dental records. A total of 169 subjects (22.4%) had high dental anxiety (DFS>59 or DBS>47 at age 20 yr), and 124 subjects (16.4%) had high frequency of missed/cancelled appointments (20% or more) during the period 12-18 yr. Forty-seven subjects (6.2%) fulfilling both of the above criteria constituted the dental avoidance group. An analysis using a stepwise regression model indicated that having had more than one painful or unpleasant treatment experience increased the risk of being included in the avoidance group by a factor of 10.9. Equally, adolescents who were not attending school (working or without specified occupation) increased the risk by a factor of 6.9, having a high caries experience by a factor of 5.0, and not having their dental treatment completed at the age of 18 yr by a factor of 4.4.

Adolescent↗
PubMed1999

A mathematical model of aerosol holding chambers.

A mathematical model of aerosol delivery from holding chambers (spacers) was developed incorporating tidal volume (VT), chamber volume (Vch), apparatus dead space (VD), effect of valve insufficiency and other leaks, loss of aerosol by immediate impact on the chamber wall, and fallout of aerosol in the chamber with time. Four different spacers were connected via filters to a mechanical lung model, and aerosol delivery during "breathing" was determined from drug recovery from the filters. The formula correctly predicted the delivery of budesonide aerosol from the AeroChamber (Trudell Medical, London, Ontario, Canada), NebuChamber (Astra, Södirtälje, Sweden) and Nebuhaler (Astra) adapted for babies. The dose of fluticasone proportionate delivered by the Babyhaler (Glaxco Wellcome, Oxbridge, Middlesex, UK) was 80% of that predicted, probably because of incomplete priming of this spacer. Of the above-mentioned factors, initial loss of aerosol by impact on the chamber wall is most important for the efficiency of a spacer. With a VT of 195 mL, the AeroChamber and Babyhaler were emptied in two breaths, the NebuChamber in four breaths, and the Nebuhaler in six breaths. Insufficiencies of the expiratory valves were demonstrated by comparison of pressure flow curves during "inspiratory" flow with and without occluded expiratory openings. Insufficient inspiratory valves were demonstrated by comparison of "expiratory" pressure flow curves with and without occluded inspiratory openings. With children breathing through the spacers, mask pressure variations were generally on the same order as that seen with the mechanical respiratory, supporting the clinical relevance of the in vitro findings.

Aerosols↗
PubMed1998

Broadening the Tests of Learning Models.

For many years psychological studies of the learning process have used a simulated medical diagnosis task in which symptom configurations are probabilistically related to diseases. Participants are given a set of symptoms and asked to indicate which disease is present, and feedback is given on each trial. We enrich this standard laboratory task in four different ways. First, the symptoms have four possible values (low, medium low, medium high, and high) rather than just two. Second, symptom configurations are generated from an expanded factorial design rather than a simple factorial design. Third, subjects are asked to make a continuous judgment indicating their confidence in the diagnosis, rather than simply a binary judgment. Fourth, cumulated performance scores, payoffs, and the availability of a historical summary of the outcomes are varied in order to assess how these treatments modulate performance. These enrichments provide a broader data set and more challenging tests of the models. Using 123 subjects each in 480 trials, we compare five existing learning models plus several variants, including the well-known Bayesian, fuzzy logic, connectionist, exemplar, and ALCOVE models. We find that the subjects do learn to distinguish the symptom configurations, that subjects are quite heterogeneous in their response to the task, and that only a small part of the variation across subjects arises from the differences in treatments. The most striking finding is that the model that best predicts subjects' behavior is a simple Bayesian model with a single fitted parameter for prior precision to capture individual differences. We use rolling regression techniques to elucidate the behavior of this model over time and find some evidence of over-response to current stimuli. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Dental anxiety among 18-yr-olds in Norway. Prevalence and related factors.

The aims of this study were to determine the prevalence of dental anxiety at the time when adolescents are leaving the public dental service, and to explore the relationship at this stage between dental anxiety and some possible etiologic factors. The sample consisted of 571 18-yr-olds in high school who completed a questionnaire and three psychometric scales, the Dental Fear Scale (DFS), the Dental Beliefs Survey (DBS) and the Geer Fear Scale (GFS), in the classroom. The relationship between dental anxiety (DFS and DBS) and a total of nine possible etiologic factors was explored by the use of stepwise regression analyses, and risk estimates (odds ratio) were calculated in cross-tables. There were significant sex differences for DFS and for GFS, but not for DBS. Nineteen percent of the total sample were classified as having high dental anxiety (DFS > 59). Previous experiences of pain, phobic anxiety indexed by GFS and pain at the last dental visit entered into the stepwise regression models of both dental anxiety indices explaining 50% of the variance of DFS, but only 18% of DBS. Students who reported more than one previous experience of pain were 9.9 times more likely to report high dental anxiety as recorded by DFS than the rest of the group. The corresponding risk factor for DBS was 3.4.

Adolescent↗
PubMed1998

Missed and cancelled appointments among 12-18-year-olds in the Norwegian Public Dental Service.

The aims of this study were to evaluate the prevalence and distribution of missed and cancelled dental appointments in the Norwegian Public Dental Service during the age period from 12 to 18 yr, and to explore possible relationships with demographics and individual caries experience (DMFT). A total of 968 patients (86.5% of the sample) gave their consent to collect data from their dental records. Forty-seven % of the group had missed and 26% had cancelled one or more dental appointments. A total of 13.6% had missed more than 20% of their appointments. Missed and cancelled appointments were to a great extent related to different individuals. The frequency of individuals with missed and cancelled appointments showed an almost linear increase from age 12 to 18 yr, and the mean individual frequency increased from 1.1 to 11.8% for missed appointments and from 0.7 to 4.8% for cancelled appointments. Subjects with missed appointments had a significantly higher mean DMFT at the age of 18 compared with the rest of the group. Individuals with missed and cancelled appointments may represent a risk group for future dropout from dental care which should be further analyzed.

Adolescent↗
PubMed1998

The ability of Corah's Dental Anxiety Scale and Spielberger's State Anxiety Inventory to distinguish between fearful and regular Norwegian dental patients.

The purpose of this study was to test the ability of Corah's Dental Anxiety Scale (DAS) and Spielberger's State Anxiety Inventory (STAI-S) to distinguish between fearful (n = 145) and regularly attending (n = 156) Norwegian dental patients. The reliability of both instruments was high (Cronbach's alpha indices > 0.95). With DAS, 90% of the fearful patients and 85% of the reference patients were correctly assigned to their appropriate group. Thus it may be concluded that, when used on a Norwegian population, DAS is a valid instrument for distinguishing fearful patients from those regularly attending dental treatment. The corresponding figures for STAI-S were 80% for the fearful patients and 79% for the reference patients. Although not developed specifically for this purpose, this instrument may therefore still validly be used to distinguish between the groups. The correlation between the instruments was 0.76, indicating that to some extent they measure the same phenomenon.

Adult↗
PubMed1998

Epidural analgesia with bupivacaine does not improve splanchnic tissue perfusion after aortic reconstruction surgery.

Inadequate splanchnic tissue perfusion is relatively common during and after aortic surgery. We hypothesized that vasodilation caused by thoracic epidural analgesia improves splanchnic blood flow and tissue perfusion after aortic surgery. In this prospective, randomized, controlled study, we studied 20 patients undergoing elective aortic-femoral or aortic-iliac reconstruction surgery. Gastric and sigmoid colon mucosal PCO2 and pH were measured during surgery. An epidural bolus of bupivacaine 40 mg followed by infusion of 15 mg h-1 was started after operation in 10 patients. After operation, splanchnic blood flow and gastric and sigmoid colon mucosal PCO2 and pH were measured before and 2 h after the start of epidural analgesia. During surgery, the gastric mucosal-arterial PCO2 difference remained stable, whereas the sigmoid mucosal-arterial PCO2 difference increased during aortic clamping but returned to pre-clamping values after declamping. After operation, epidural analgesia had no effect on gastric or sigmoid mucosal-arterial PCO2 differences or on splanchnic blood flow.

Acidosis↗
PubMed1998

In vitro performance of three combinations of spacers and pressurized metered dose inhalers for treatment in children.

The performance of pressurized metered dose inhalers (pMDIs) and spacers in correct dose recommendations is important, but limited information on dose delivery and fine-particle dose from different combinations of spacers and pMDIs is available. In this study, three combinations of spacers and pMDIs were investigated: NebuChamber and AeroChamber with budesonide pMDI and Babyhaler with fluticasone propionate pMDI. Doses were withdrawn onto a filter either with a breathing simulator (dose to ventilator) or with constant flow (maximal dose). The fine-particle dose was assessed with a cascade impactor (Andersen Sampler). The effect of repeated use and cleaning of the spacers on the passive fallout of aerosol within the spacers was determined by evacuating the dose on a filter 2, 5, 10 and 30 s after actuating the spray. The drugs were quantified by liquid chromatography. The NebuChamber delivered the highest doses, both maximal dose and dose to ventilator. The recovered doses (means+/-SD) were 55+/-6% and 51+/-2%, respectively, of the delivered dose from the pMDI. The corresponding results for the Babyhaler were 41+/-7% and 24+/-4% and for the Aerochamber 27+/-3% and 17+/-3%. The passive fallout of aerosol, determined as half-life (t1/2) was around approximately 30 s for the NebuChamber, 9-15 s for the Babyhaler and approximately 10 s for the AeroChamber. The present study confirms that there are significant differences in dose output from different combinations of pressurized metered dose inhalers and spacers, with the NebuChamber giving the highest dose, both as delivered dose and in droplets <4.7 microm. Interactions with the spacer material, dead space in the inspiratory line and entrainment of air during inhalation due to inefficient valve control could account for these differences.

Aerosols↗
PubMed1998

[Early postoperative complications after different methods of intestinal reconstruction in deep anterior rectum resection--a prospective study].

For the first period after low anterior resection and total mesorectal excision for rectal cancer, the colonic J-pouch is superior to the straight or lateroterminal anastomosis. Despite the simple technique and short stretch of sutures, the LTA is unsuitable due to the high postoperative morbidity and because the reconstruction functions poorly. If the expected anastomis is below 6 cm from the anal verge, i.e. 4 cm above the sphincter muscle, the colonic J-pouch is recommended.

Adult↗
PubMed1997

Retinal Muller glia secrete apolipoproteins E and J which are efficiently assembled into lipoprotein particles.

We have shown that apolipoprotein E (ApoE) is synthesized by Muller cells, the major glial cell of the rabbit retina, and secreted into the vitreous after which it is taken up by retinal ganglion cells and rapidly transported into the optic nerve [Amaratunga et al., J. Biol. Chem. 271 (1996) 5628-5632]. In this report we demonstrate that the ApoE secreted by Muller cells in vivo and in culture is efficiently assembled into lipoprotein particles. Apolipoprotein J (ApoJ) is also synthesized by these cells and assembled into lipoprotein particles. The lipoproteins are triglyceride-rich and contain cholesterol esters and free cholesterol. They are heterogeneous, with densities between 1.006 and 1.18 and diameters between 14 and 45 nm. We discuss the possible role of these lipoproteins in supplying the needs of neurons for lipids, especially long axonal projection neurons such as retinal ganglion cells, which are vulnerable to age-related neurodegenerative diseases including Alzheimer's disease.

Animals↗
PubMed1997

Mouse mastocytoma cells synthesize undersulfated heparin and chondroitin sulfate in the presence of brefeldin A.

In order to study the subcellular localization and organization of the enzymes involved in the glycosylation of the hybrid proteoglycan serglycin, mouse mastocytoma cells were metabolically labeled with [35S]sulfate or [3H]glucosamine in the absence or presence of brefeldin A. This drug is known to induce a disassembly of the proximal part of the Golgi complex, resulting in a redistribution of cis-, medial-, and trans-Golgi resident enzymes back to the endoplasmic reticulum, and to block the anterograde transport of proteins to the trans-Golgi network. Although the total incorporation of [3H]glucosamine into glycosaminoglycan chains was reduced to about 25% in brefeldin A-treated cells compared to control cells, both control cells and cells treated with brefeldin A synthesized heparin as well as chondroitin sulfate chains. Therefore, enzymes involved in the biosynthesis of both types of glycosaminoglycan chains seem to be present proximal to the trans-Golgi network in these cells. Chondroitin sulfate and heparin synthesized in cells exposed to brefeldin A were undersulfated, as demonstrated by ion-exchange chromatography, compositional analyses of disaccharides, as well as by a lower [35S]sulfate/[3H]glucosamine ratio compared to controls. In heparin biosynthesis, both N- and O-sulfation reactions were impaired, with a larger relative decrease in 2-O-sulfation than in 6-O-sulfation. Despite undersulfation, the heparin chains synthesized in the presence of brefeldin A were larger (30 kDa) than the heparin synthesized by control cells (20 kDa). The reduced [3H]glucosamine incorporation in brefeldin A-treated cells was partly due to decreased number of glycosaminoglycan chains synthesized, but also to the biosynthesis of chondroitin sulfate chains of smaller molecular size (8 versus 15 kDa in control cells). Brefeldin A had no effect on the glycosaminoglycan synthesis when used in a cell-free, microsomal fraction, indicating that brefeldin A does not interfere directly with the enzymes involved in the biosynthesis of glycosaminoglycans.

Animals↗