Showing papers by "Swedish Institute published in 1995"

Human B‐cell epitopes of puumala virus nucleocapsid protein, the major antigen in early serological response

Abstract: Puumala virus (PUU) is a member of the Hantavi rus genus in the family Bunyaviridae and the etiologic agent of nephropathia epidemica (NE), a form of haemorrhagic fever with renal syndrome (HFRS). In this study we compared the immunofluorescence patterns of NE sera and antibodies raised against recombinant PUU proteins and confirm that the nucleocapsid protein is the major target in the early IgG response of NE patients and provides the molecular basis for simple and rapid differentiation between acute illness and old immunity by granular vs. diffuse fluorescence staining in the indirect immunofluorescence test. The differential kinetics of B-cell responses to PUU nucleocapsid vs. envelope proteins was emphasized further by the end-point titres of IgG antibodies to N, G1 and G2 proteins in NE patients. The granular fluorescence correlated with low IgG avidity in 99.8%. and diffuse fluorescence with high avidity in 100% of 617 NE sera studied. Epitope scanning with overlapping 14-mer peptides covering the whole nucleocapsid protein by a shift of 3 amino acids revealed six major antigenic epitopes recognized by sera from acute-phase NE patients. The epitopes clustered mainly in the hydrophilic regions, and two of them in a highly variable region which could probably serve as an antigen to distinguish serologically between infections of closely related hantaviruses, some apparently apathogenic, some causing lethal infections. The anti-peptide epitope pattern varied between different individuals and a collection of several pinbound peptides was needed to be recognised by most NE sera studied. © 1995 Wiley-Liss, Inc.

Temporal dynamics of Puumala virus antibody prevalence in voles and of nephropathia epidemica incidence in humans.

Abstract: Puumala (PUU) virus is the etiologic agent of nephropathia epidemica (NE) in humans. This disease is highly endemic in Vasterbotten county, Sweden, with an annual incidence of 19.2 (range 3.7-37.4) per 100,000 inhabitants. Voles are considered to be both the main reservoir and the vector of PUU virus. A total of 3,591 rodents (mainly Clethrionomys glareolus, C. rufocanus, and Microtus agrestis) trapped in Vasterbotten between 1979 and 1987 were tested for the presence of PUU virus antibodies by enzyme-linked immunosorbent assay. The predominant species, C. glareolus (71% [2,544 of 3,591]), also had the highest antibody prevalence (19% [483 of 2,544]). In C. glareolus, the antibody prevalence rate increased with weight (age), reaching more than 50% in the heaviest weight group, and suggesting that horizontal infection may be important. The highest frequency (25%) of antibody-positive C. rufocanus was also found in the highest weight groups. Microtus agrestis showed low absolute numbers and a low antibody prevalence rate (5%). In C. glareolus, both antibody prevalence and weight were recurrently higher in the spring than in the previous fall. The antibody prevalence rate in spring was positively correlated with the vole density in the previous fall and spring. The fall antibody prevalence rate was directly dependent on C. glareolus density. The incidence of human NE in the fall was dependent on the concurrent density of C. glareolus, whereas the incidence of NE in the spring was dependent on vole density the previous fall.

A new conceptualization of union commitment: Development and test of an integrated theory.

Abstract: An introductory conceptual and empirical review stresses the need for a stable theoretical basis for union commitment research The purpose of this paper is to develop a new conceptualization of union commitment based on the integration of two theories (the theory of reasoned action and the rationalistic approach to commitment) The integrated theory suggests that union commitment is composed of two dimensions, one based on instrumentality and one based on ideology, which are causally related to prounion behavioral intentions and, in turn, to union participation Propositions derived from the integrated theory are tested using data on 1486 blue‐collar workers in Sweden Results of linear structural equation modelling with latent variables and of multiple regression analyses provide strong support for the construct validity of the commitment dimensions and the overall applicability of the integrated theory The central findings, their conceptual implications for the understanding of union commitment, and their practical implications for unions are discussed

Incidence, Capsular Types, and Antibiotic Susceptibility of Invasive Streptococcus pneumoniae in Sweden

Abstract: The number of reported cases of invasive pneumococcal infections in Sweden increased more than threefold from 1988 through 1992. We studied the capsular types and the antibiotic susceptibility of 619 pneumococcal strains isolated from blood or CSF at 18 Swedish microbiological laboratories in 1987 and in 1992. These strains belonged to 35 of the 84 recognized capsular types. We noted a remarkable increase in the prevalence of invasive infections with type 14 from 1987 (8.2%) to 1992 (18%) (P = .001), which correspond to a sevenfold increase in absolute numbers. The most prominent increase in infections was seen among elderly people; in 1992, type 14 accounted for 22.5% of the isolates from infected persons who were >64 years of age. The majority of the strains were susceptible to all antibiotics tested. However, there was a significant increase in trimethoprim-sulfamethoxazole resistance from 1.4% in 1987 to 7.1% in 1992. Nine multiresistant isolates (1.5%) were found.

Liquid-holding capacity and structural changes in comminuted salmon (Salmo salar) muscle as influenced by pH, salt and temperature

Abstract: The loss of liquid in salmon muscle comminuted with salt was studied as a function of pH and heating temperature. A factorial experiment was designed to compare the effects of; the raw material, NaCl concentration, pH, degree of comminution and heating temperature in order to evaluate both main effects and interaction effects. The liquid-holding capacity was measured by a low speed centrifugation net test. The changes in microstructure in the samples were investigated by light microscopy using fat- and protein-staining techniques. The heating temperature, pH, NaCl concentration, variation of raw material and degree of comminution influenced liquid loss according to a second-order interaction linear model. The interaction effect between low pH, low salt concentration and high temperature was strongest. Addition of salt extracted the myofibrillar proteins and resulted in a homogeneous protein matrix with few intact fibres and uniformly dispersed fat droplets. Liquid loss was closely related to the microstructure of the comminutions. When heated above 30 °C, enlarged pores and gaps, some of them forming channels, occurred in the protein matrix. In comminutions prepared with a low salt concentration and/or a low pH the more frequent presence of pores and gaps enhanced the liquid loss.

An Overview of Advances in Conductive Adhesive Joining Technology for Electronics Applications

Abstract: Poly-meric electronic packaging u.sing conductive adhesives is expected to become a key technology for the assembly and manufacturing of electronics. It offers many advantages compared with conventional leadsolder based technology including lower processing temperature, environmental compatibility, simpler processing, and lower cost. Achievements worldwide in polymeric electronic packaging using conductive adhesives for electronics manu.facttlling at re earch institutes, universities, and electronic manufacturers are described. Particular note is made of R&D in the United States, in central Europe, and in the Scandinavian countries. Future challenges, problems, and trends are also discussed. Polymeric packaging in electronics is shown to be playing a significant role in electronics manufacturing that will become of increasing importance with many more applications anticpated in the future.

Antigenic relationships of hantavirus strains analysed by monoclonal antibodies

Abstract: The antigenic relationships among 71 hantavirus strains, isolated from rodent species or humans in several geographic regions, were examined by immunofluorescence assay (IFA) using human patient sera and a panel of 22 monoclonal antibodies prepared against Hantaan, Seoul, and Puumala viruses. The study included virus strains, mainly from the former USSR, for which little or no serological data were available. Fifty-nine of the 71 isolates could be placed into five antigenic groups of hantaviruses, Hantaan (HTN), Puumala (PUU), Seoul (SEO), Prospect Hill (PH), Dobrava/Belgrade (DOB). Twelve isolates were found antigenically closely related to, but distinct from, HTN (2 strains), PUU (4 strains) and PH (6 strains), respectively. The antigenic characteristics of these 12 isolates suggested two supplementary antigenic subgroups of HTN, one of PUU, and two of PH. The two antigenic subgroups of HTN included strains isolated in the Far-East of Russia. The PUU subgroup included strains isolated in European Russia as well as strains isolated in Far-Eastern Russia. The PH group comprised two subgroups, both represented by strains isolated from M. fortis in Far-Eastern Russia. The results showed that the PUU and PH antigenic groups are more complex than previously known and that PH-like virus strains isolated in Russia are antigenically more closely related to PUU virus when compared to prototype PH virus isolated in the USA.

Topical Treatment of Diabetic Foot Ulcers: an Economic Analysis of Treatment Alternatives and Strategies

Abstract: In a prospective study, 314 patients with diabetic foot ulcers were followed and 40 patients died before healing occurred. In those patients who healed, a retrospective economic analysis of the costs for topical treatment was performed. The aim of the study was to analyse the costs and discuss how different treatment strategies influence total costs. Data collected for each patient were total time to healing, treatment time for each type of dressing, and the frequency of dressing changes. Material costs for the dressings, labour, and travelling costs were calculated separately. A formula for simulation of economic consequences of different treatment strategies including the introduction of new strategies was designed. The cost for topical treatment was strongly related to the severity of the ulcer and wound healing time. The average weekly cost per patient for topical treatment varied between 40.3 pounds and 385 pounds. The dominating costs for topical treatment were expenses for staff and transportation. The most important factor to reduce costs is the frequency of dressing changes. The study emphasizes the need for prospective comparative studies of cost effectiveness in topical treatment strategies.

Frozen storage and thawing methods affect biochemical and sensory attributes of rainbow trout

Abstract: Rainbow trout were subjected to four thawing treatments after being stored at -18°C and -40°C for 0, 3, 7, 13 and 18 mo. Membrane integrity was estimated as the volume of centrifuged tissue fluid (CTF) and by lysosomal β-N-acetylglucosaminidase (NAG) activity in CTF. Slow thawing, in air at 5°C, resulted in higher NAG activity in CTF and a larger volume of CTF than fast thawing, at 25°C in water, independent of storage time. After 3 or more months storage, a higher NAG activity in CTF and a larger volume of CTF were found in all -18°C stored samples compared to that at -40°C. Sensory evaluation confirmed differences between trout stored at -18°C and at -40°C for 18 mo.

Cost-effectiveness analysis in early detection of prostate cancer: an evaluation of six screening strategies in a randomly selected population of 2,400 men.

Abstract: Based on the findings in an early detection study for prostate cancer [Gustafsson et al.: J Urol 148:1827-1831, 1992] using digital rectal examination (DRE), transrectal ultrasound (TRUS), and prostate-specific antigen (PSA), a cost-effectiveness analysis was performed based on 6 screening strategies, namely: 1) DRE of all individuals; 2) TRUS of all individuals; 3) DRE, TRUS, and PSA analysis followed by reexamination of individuals with PSAs > or = 7 ng/ml; 4) DRE of individuals with PSAs of > or = 4 ng/ml; 5) TRUS of individuals with PSAs of > or = 4 ng/ml; 6) DRE and PSA analysis followed by TRUS on individuals with PSAs > or = 4 ng/ml. The detection rates of prostate cancer using these 6 strategies were 2.4%, 3.3%, 3.6%, 2.0%, 2.6%, and 3.2%, respectively. Except for costs per detected cancer, costs were also calculated per detected small cancer ( or = 4 ng/ml (strategy 5) was the most cost-effective strategy and detected 80% of the cancers actually treated for cure. Screening with DRE and PSA analysis followed by TRUS of individuals with PSAs > or = 4 ng/ml (strategy 6) had a somewhat lower cost-effectiveness, but detected 90% of the cancers treated for cure.

Ganciclovir therapy for cytomegalovirus (CMV) infection of the central nervous system in AIDS patients: monitoring by CMV DNA detection in cerebrospinal fluid.

Abstract: Seven AIDS patients with central nervous system (CNS) disease and cytomegalovirus (CMV) DNA in cerebrospinal fluid (CSF) were evaluated before and 3 weeks after standard ganciclovir treatment by nested polymerase chain reaction (PCR) on limiting dilutions and by quantitative PCR. After therapy, PCR CSF was negative for CMV in 3 patients with low baseline levels of CMV DNA and positive with decreased DNA titers in 4 patients with higher baseline levels. CMV pp65 antigen in polymorphonuclear leukocytes was found in 6 of 7 patients before therapy and in none of 5 after therapy. At autopsy, CMV was found in the CNS of the 4 cases examined, including 3 whose CSF was continuously positive by PCR. Quantitative PCR of CSF is useful for monitoring ganciclovir treatment in CMV infection of the CNS. In AIDS patients, standard ganciclovir treatment seems effective in reducing but not suppressing viral replication in severe cases of CMV infection of the CNS.

Development of conductive adhesive joining for surface-mounting electronics manufacturing

Abstract: This paper presents the results of a study of process development for conductive adhesives as solder replacement. The main objective of the work was to investigate the potentials for using conventional surface-mounting equipment for component assembly with conductive adhesives. Two processes have been studied: one which uses both anisotropically and isotropically conductive adhesives and one which uses isotropically conductive adhesives only. The results from the work show that currently available surface-mounting machinery can be used for the conductive adhesive joining process. However, further work is needed to optimize the processing conditions. Transmission electron microscopy analysis of the adhesive joints after temperature cycling and humidity testing shows that oxide layer formation on metal surfaces can be one of the mechanisms which causes decrease in the electrical performance of the joint. >

An epidemic of Plasmodium falciparum malaria in Balcad, Somalia, and its causation

Abstract: The causative factors of an epidemic of falciparum malaria were investigated in Balcad, Somalia, a town with previously low malaria transmission, where malaria incidence rose more than twenty-fold between 1986 and 1988. The emergence of chloroquine resistance, accelerated by high drug pressure, low herd immunity and favourable meteorological conditions were identified as major causes of the epidemic. Chloroquine resistance of grades RII and RIII was first observed in Balcad in 1987 and rapidly increased to 72% of the Plasmodium falciparum infections in 1988. In the absence of alternative treatment, resistance resulted in the accumulation of a massive infective reservoir and therefore increased malaria transmission, associated with intensive clinical symptomatology. The advent of chloroquine resistance was less violent in the area of Malable, where malaria is stable and communal immunity higher than in Balcad.

Hepatitis E virus infections in patients with acute hepatitis non-A-D in Sweden

Abstract: A total of 12 patients previously treated for acute hepatitis of unknown aetiology were retrospectively found to be anti-hepatitis E virus (HEV) IgG-positive. Four patients were anti-HEV IgM- and IgG-positive consistent with an acute HEV infection. All 4 had travelled to or were immigrants from HEV-endemic countries. One anti-HEV IgM-negative patient seroconverted from anti-HEV IgG-negative to positive and 3 from anti-HEV IgG-positive to negative in 2 consecutive serum samples. Of the remaining 4 patients without anti-HEV IgM, 3 had a history of recent travel to an HEV-endemic country. Most patients were young adults and all but 1 recovered from the hepatitis. One patient with a fulminant hepatitis was anti-HEV IgG-positive when tested 4 months after a journey to Turkey. She died from her fulminant hepatitis shortly after admission. All the other patients but 1 normalized their serum liver enzymes within 1-2 months after the onset of disease.

The economic cost of a streptococcal tonsillitis episode

Abstract: Setting - Five primary health centres in the west of Sweden.Participants - 101 consecutive patients treated for streptococcal tonsillitis.Main outcome measure - the cost estimation included costs f...

A national telepathology trial in Sweden feasibility and assessment.

Abstract: Un essai de la telepathologie fut organise en Suede pour evaluer plusieurs parametres tels que la realite d'un souhait et d'un besoin, la facilite de manipulation, la qualite de l'image et la recevabilite d'un systeme a images fixes pour la teleconsultation entre pathologistes. De septembre 1992 a decembre 1993, six systemes de telepathologie furent loues et installes provisoirement pendant huit a dix semaines dans vingt-neuf services d'anatomo-cyto-pathologie dans les divers hopitaux suedois. Trois systemes de telepathologie furent achetes par les hopitaux universitaires de Gothenburg, de Linkoping et Uppsala et ont servi de postes permanents. Pour evaluer ce projet, des questionnaires pre- et post-tests furent adresses a tous les anatomo-pathologistes et cytologistes participants, interrogeant les reactions, les attentes et constatations et les souhaits pour le futur. Bien que d'autres methodes d'evaluation etaient prevues dans le projet, cet article se limite a l'etude des resultats des questionnaires. Cette etude revele que le principal besoin medical pour la telepathologie en Suede concerne essentiellement des problemes de diagnostics des cancers en general, des grades de malignite, des tumeurs des tissus mous, de l'os, du sein, de l'appareil uro-genital et accessoirement des problemes dans les domaines de la dermatologie, des inflammations et des transplantations d'organes. La telepathologie devrait ameliorer la fiabilite des diagnostics dans 37 % des reponses pre-tests et 31 % des reponses post-tests. Cette chute peut correspondre soit a une attente trop optimiste, soit a des conditions de test defectueuses. Le systeme utilise etait a images fixes et l'evaluation revela clairement que les anatomocyto-pathologistes prefereraient un systeme a images mobiles pour le futur. La resolution de l'image est essentielle et fut jugee insuffisante pour toutes les utilisations au cours de l'etude. Neanmoins, la moitie des repondeurs souhaitent avoir un systeme de telepathologie dans leur propre service. Les resultats de cette enquete sont donc encourageants et vont contribuer a guider le choix des developpements ulterieurs dans ce domaine.

The influence of machining defects and inclusions on the fatigue properties of a hardened spring steel

Abstract: In hardened steel with high tensile strengths the fatigue strength is often limited by defects, either surface defects or interior defects. In this work the influence of different surface conditions on the fatigue strength of a hardened spring steel has been studied. The fatigue limit of hour-glass shaped specimens with turned, ground or polished surface was found using load-controlled testing combined with the stair-case method. A model based on a statistical treatment of the machining defects (surface) and the inclusions (interior) combined with fracture mechanics has been used to predict the fatigue limit. It was intended to consider the total effect of surface defects and interior defects. The model also makes it possible to predict the failure mode, i.e. surface-defect initiated failures or inclusion-initiated failures.

Fatigue of a highly prestrained dual-phase sheet steel

Abstract: The effect of prestraining by 15-30% and ageing on the fatigue properties of a cold-rolled high-strength dual phase sheet steel was investigated. Prestraining was performed before machining the fatigue specimens and was carried out in uniaxial as well as biaxial tension. Fatigue testing was carried out under fully reversed strain control and both the cyclic stress-strain behaviour and the fatigue lives were recorded. Significant fatigue strength improvements by up to 50% were noted for the prestrained material as compared to the as-received condition. During fatigue testing in uniaxially prestrained conditions, the occurrence of mean stresses was noted. These mean stresses were persistent when testing at levels corresponding to longer fatigue lives. Taking into account an estimation of these mean stresses and the increase of monotonic strength, modelling of fatigue resistance for the prestrained materials shows fairly good correlation with experimental results.

Sensory and chemically measured effects of different freeze treatments on the quality of farmed rainbow trout

Abstract: Sensory and biochemical analyses were done on farmed rainbow trout to estimate quality changes caused by four different freeze handling processes. Trout were frozen as a block (I) and individual (II) drawn fish, and as a block (III) and individual (IV) fillets. Refreezing was done, except for group IV, after filleting group I and II and separating group III into individual filets. A 9-month storage period followed (-30C). Enzyme activity of α-glucosidase (AG) and β-N-acetylglucosaminidase (NAG) was measured in centrifuged tissue fluid (CTF). A descriptive sensory test was done after the second thawing and a ranking-order test after frozen storage. Refreezing resulted in significant increases (p < 0.05) of both enzyme activities in all groups. After storage the activity of NAG was significantly higher (p < 0.05) in all groups and a difference (p < 0.05) between group I and II was also seen. In the descriptive sensory evaluation, only two sensory attributes of group IV were differentiated (p < 0.05, p < 0.01) from the other groups. After storage group II was the preferred group (p < 0.05).

The indirect costs of morbidity in type II diabetic patients.

Abstract: In an attempt to obtain an appropriate estimate of the excess costs of production losses arising from morbidity in patients with diabetes, we compared the number of sick days and permanently disabled individuals in a diabetic population and the corresponding general population. These comparisons show that the rate of premature retirement for both insulin-dependent diabetes mellitus (IDDM, type I diabetes) or non-insulin-dependent diabetes mellitus (NIDDM, type II diabetes) patients was twice that of the average population. Insulin-treated subjects also had twice as many sickness benefit days. The excess costs of production losses as a result of morbidity in people aged 20 to 64 years with type II diabetes were about $US7000 per individual and year. Most of these excess costs were attributed to permanent disability in the 40- to 64-year age groups.

Reliability of Electronics in Harsh Environments

Abstract: This paper reports experiences gained in several research programmes, showing the necessity to develop improved environmental tests that better accelerate the mechanisms that degrade electronics The tests specified in standards today do not consider relevant failure mechanisms The paper describes the authors' philosophy for performing reliability testing Examples of various reliability tests are given