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S Olsson

Publications and source records attributed to S Olsson.

At least 55 records · Page 3Linked to original sources
PubMed1997

The effect of comonomer composition, silane heating, and filler type on aqueous TEGDMA leachability in model resin composites.

Experimental composites using either bisGMA/TEGDMA or UEDMA/ TEGDMA matrices, quartz or barium glass fillers, and 2 different filler silanization methods were evaluated regarding monomer leachability in distilled water. The leached amount was detected and quantified using gas chromatography. The results showed that twice as much TEGDMA is leached from a bisGMA/TEGDMA based composite than from an UEDMA/ TEGDMA based composite, when both contain 50 wt% TEGDMA. The hypothesis suggested that the higher degree of cure of UEDMA/TEGDMA based composites would be reflected in a lower monomer leaching value, and this hypothesis was supported by the findings. Whether such a correlation exists within groups of UEDMA/TEGDMA based matrices having different degrees of cure was not determined and needs to be investigated in future studies. Variables such as filler composition and silane treatment did not affect the leaching values of TEGDMA in water. That finding suggests that future studies should target differences in matrices, and that the need for considering effects of filler composition and silane treatment methods should not receive the same priority.

Analysis of Variance↗
PubMed1997

Connections between polarization curves and log(a[i]/a[ref])-pe diagram.

When reading papers concerning studies of corrosion of dental amalgam and its phases by means of polarization curves, one often finds it difficult to understand the reasons for the chemical reactions proposed from the form of the polarization curve. Thermodynamic data represented in the form of log(a[i]/a[ref])-pe diagrams, i.e., the logarithm of the activity of a metal or an alloy with reference to the activity of the corresponding metal ion, as a function of pe (a recalculated form of the potential), make it possible for one to determine which chemical reactions can occur on the specimen surface or in the solution within the potential difference used in the polarization experiment and to decide which of these reactions is the most probable. The hypothesis examined in this study is that a log(a[i]/a[ref])-pe diagram can be used in the interpretation of polarization curves. Potentiodynamic polarization curves and log(a[i]/a[ref])-pe diagrams were compared for the corrosion of Ag, Hg, and gamma 1 with and without Sn. It was found that there was a connection between the polarization curves and the log(a[i]/a[ref])-pe diagrams. From the composition of the specimens and the solution and by means of thermodynamic data, pe values for solid corrosion products and relative concentrations of soluble complexes at these pe values were obtained independently of the polarization curves. A much more reliable value for the nobility of metals and alloys was attained by use of the log(a[i]/a[ref])-pe diagrams than by use of the potential of the starting point of the polarization curves. It was found that pe corresponding to the potential of the starting point of the polarization curves in de-aerated synthetic saliva was obtained about two pe units before pe of the most insoluble solid compound formed on the specimen surface or in the solution.

Corrosion↗
PubMed1997

Allergenic crossreactivity between Lepidoglyphus destructor and Blomia tropicalis.

BACKGROUND: In general, the non-pyroglyphid mites Lepidoglyphus destructor and Blomia tropicalis show a different geographical distribution. Allergic sensitization to both species have been demonstrated in several investigations. However, whether this reflects cross-reactivity or dual sensitization is so far not known. OBJECTIVE: The aim of the study was to investigate the allergenicity and allergenic crossreactivity of L. destructor and B. tropicalis using sera from Sweden and Brazil. METHODS: Allergens in extracts of L. destructor and B. tropicalis were identified with SDS-PAGE and immunoblotting and the crossreactivity was studied by an immunoblot inhibition method. In addition to mite extracts, a recombinant major allergen of L. destructor, Lep d 2, was used. RESULTS: The extract prepared from L. destructor contained 21 IgE-binding components when using the Swedish or the Brazilian sera. A 15 kDa allergen was recognized by 85% of the Swedish sera and 78% of the Brazilian. The B. tropicalis extract exposed 23 IgE-binding components when the Brazilian sera were used and 19 when the Swedish sera were used. A total of 83% of the Brazilian sera and 80% of the Swedish sera identified a 14.5 kDa allergen. The IgE response of the Swedish serum pool to 10 B. tropicalis allergens was inhibited by L. destructor extract. Likewise, the response of the Brazilian serum pool to four different L. destructor allergens was inhibited by B. tropicalis extract. The recombinant Lep d 2 allergen inhibited 33% of the IgE binding of the Swedish serum pool to the 14.5 kDa allergen in the B. tropicalis extract. CONCLUSION: Crossreactivity with several proteins from L. destructor and B. tropicalis was demonstrated. The results suggest that a B. tropicalis 14.5 kDa allergen is antigenically crossreactive with recombinant L. destructor allergen Lep d 2.

Allergens↗
PubMed1996

The relation of passage of gas an abdominal bloating to colonic gas production.

OBJECTIVE: To determine the relation of gas passage and abdominal bloating to the production of gas in the colon. DESIGN: Randomized, double-blind, crossover study of gaseous symptoms during a 1-week period. SETTING: A Veterans Affairs medical center. PARTICIPANTS: 25 healthy medical center employees. INTERVENTION: Participants' diets were supplemented with either a placebo (10 g of lactulose, a nonabsorbable sugar), psyllium (a fermentable fiber), or methylcellulose (a nonfermentable fiber). MEASUREMENTS: All participants were polled for gaseous symptoms (including number of gas passages, impression of increased rectal gas, and abdominal bloating), and five were examined for breath hydrogen excretion. RESULTS: Participants passed gas 10 +/- 5.0 times per day (mean +/- SD) during the placebo period. A significant increase in gas passages (to 19 +/- 12 times per day) and a subjective impression of increased rectal gas were reported with lactulose but not with either of the two fiber preparations. Breath hydrogen excretion, an indicator of hydrogen production in the colon, did not increase after ingestion of either of the fibers. However, a statistically significant (P < 0.05) increase in feelings of abdominal bloating (which the participants perceived as excessive gas in the bowel) was reported with both fiber preparations and with lactulose. CONCLUSIONS: The physician should distinguish between excessive gas (which indicates excessive gas production) and feelings of bloating (which are usually unrelated to excessive gas production). Treatment of the former consists of limiting the supply of fermentable material to the colonic bacteria. Symptoms of bloating usually indicate the irritable bowel syndrome, and therapy should be directed accordingly.

Adult↗
PubMed1995

cDNA analysis of the mite allergen Lep d 1 identifies two different isoallergens and variants.

For the first time the complete cDNA encoding two isoallergens of the non-pyroglyphid dust mite Lepidoglyphus destructor, Lep d 1, allergen has been sequenced. In addition, one of the isoallergens was found to have two variants. Oligonucleotides were designed from known amino acid sequences. The cDNA sequences were obtained by hybridizing these primers to mRNA and enhancement by the RT-PCR technique. To obtain the different complete encoding cDNA sequences and eliminate heteroduplex artifacts, we performed PCR + 1 reactions. Comparison of the amino acid sequence of the allergen shows leader sequences of 16 amino acids for both isoforms.

Amino Acid Sequence↗
PubMed1995

Pneumatosis cystoides intestinalis and high breath H2 excretion: insights into the role of H2 in this condition.

Patients with pneumatosis cystoides intestinalis have been reported to excrete excessive H2 because of a lack of H2-consuming intestinal bacteria. This study describes a patient with bacterial overgrowth and pneumatosis of the small intestine whose colonic flora avidly consumed H2 but whose small bowel flora produced but did not consume H2. There is no commonly accepted mechanism whereby excessive luminal H2 causes intramural gas. An explanation is proposed in which an initial, transitory source of intramural gas is distinguished from the mechanism that results in the persistence of the gas. Independent of the initial source of gas, rapid diffusion of H2 from the lumen into an intramural gas bubble would cause N2, O2, and CO2 to diffuse from the blood into the bubble. As a result, the bubble would expand and then persist indefinitely as long as H2 continued to diffuse from the lumen to the intramural gas collection.

Aged↗
PubMed1995

Localization of major allergens in the dust mite Lepidoglyphus destructor with confocal laser scanning microscopy.

The dust mite Lepidoglyphus destructor is the dominating source of allergens giving rise to asthma and rhinitis among farmers. In a previous study of the localization of allergens in L. destructor we demonstrated that the 39 kDa allergen is associated with digestion. Here we describe the localization of the principal 15 kDa allergen and the high molecular weight allergen complex (79 and 93 kDa) in L. destructor with confocal laser scanning microscopy (CLSM). Cryostat-cut sections of mite bodies and faecal pellets were probed with mouse monoclonal antibodies (MoAbs) raised against the allergens. The 15 kDa allergen disclosed labelling of the mite body and most of the faecal pellets but left the exoskeleton unlabelled. The binding was widespread, and most intense in the mouth region. However, some staining was also observed around the gastrointestinal tract. In contrast, the 79 and 93 kDa allergen complex stained the exoskeleton and the front part of the mite. Interestingly, we detected no labelling of the faecal pellets with the MoAb against the 79/93 kDa allergen. The study indicates that the 15 kDa allergen is associated with the digestive tract whereas the function of the 79 and 93 kDa allergen complex remains to be elucidated.

Allergens↗
PubMed1995

Acid production by human strains of Streptococcus mutans and Streptococcus sobrinus.

Acid production by washed suspensions of human strains of Streptococcus mutans (n = 18) and Streptococcus sobrinus (n = 12) was measured. The strains were isolated from infants and adolescents with varying caries experience. Some of these strains and two laboratory strains (1 S. mutans and 1 S. sobrinus) had been tested in an earlier study for their cariogenicity in hamsters. Further, 3 Streptococcus sanguis strains and 1 S. sobrinus laboratory strain were included. Acid production was determined in repeated titration experiments at a constant pH of 5.5. Higher mean acid production activities (p < 0.05) were obtained by S. sobrinus compared with both S. mutans and S. sanguis. However, large variations among the strains were found both between and within the species. No clear relationship was found between the glycolytic activity of strains and the caries prevalence of the children from whom the strains had been isolated or the caries scores in a hamster model. In conclusion, although both S. mutans and S. sobrinus have aciduric and acidogenic properties, it is difficult to relate the acid production activity of pure cultures in vitro to the caries process in vivo.

Acids↗
PubMed1995

A national telepathology trial in Sweden feasibility and assessment.

The telepathology trial in Sweden was designed to study several parameters, eg, the specific need, practical handling, image quality and acceptance of a static imaging system for consultations between pathologists. From September 1992 until December 1993, six telepathology systems were leased and temporarily installed for 8 to 10 weeks in 29 pathology departments in Swedish hospitals. Three telepathology systems were purchased by the university hospitals in Gothenburg, Linkôping and Uppsala and served as permanent nodes. To assess the project, pre and post field-test questionnaire (focusing on attitudes/expectations and experience/wishes for the future, respectively) were sent to all participating pathologists and cytologists. Although other assessment methods were included in the project, this paper concentrates on the study of questionnaire results. The study shows that the major medical requirements for telepathology in Sweden involve diagnostic questions concerning: cancers in general, grade of malignancy, malignancy of soft tissue, haematopoetic system, skeletal system, breast, uro-genital systems and applications in the field of dermatology, inflammations and transplantations. Telepathology will enhance diagnostic accuracy according to 37% of the responding physicians in the pre field-test study and 31% in the post field-test study, a drop which may reflect excessively high expectations or less than optimal test conditions. A static-image transfer telepathology system was used but the assessment clearly shows that pathologists and cytologists prefer a dynamic imaging telepathology system for the future. Image resolution is crucial and was not adequate for all applications in the study. Half of the respondents preferred having a telepathology system in their own departments.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer Communication Networks↗
PubMed1995

Future strategy for telepathology in Sweden: higher resolution, real time transmission in a multipurpose work station for diagnostic pathology.

The general reaction among Swedish pathologists to the nationwide experimentation static teletransmission of microscopic images can be briefly summarized as follows: "interesting, but technically imperfect: we need more friendly interface, faster transmission, preferably in real time, better resolution, and the possibility for slide operation by the receiver". In Sweden all Pathology laboratories are presently changing administrative routines to PC-platformed networks, which means that each pathologist has a microscope and a PC as obligatory tools to perform diagnostic work. Therefore, we plan to incorporate Telepathology, including picture archiving, along with administrative software and improved software for static DNA-measurements and morphometry. The latter is including a novel system for quantification of color images e.g. immunohistochemistry into a standard work-station for diagnostic pathology. The features of this technique are presented as well as the general outline of the work-station. Steps have been taken to build up and test such a work-station in the broad band (ATM) laboratories of the Ericsson Company and a cooperation with several Scandinavian partners in computer and teletechnology. Hopefully, similar competitive actions are taken elsewhere to help bring down the prices and facilitate adoption among diagnostic pathologists world-wide.

Computer Communication Networks↗
PubMed1994

[Tendinitis of the Achilles tendon caused by pefloxacin and other fluoroquinolone derivatives].

Four cases were reported to the Netherlands Pharmacovigilance Foundation LAREB of Achilles tendinitis, as a suspected adverse reaction to pefloxacin; the patients were two men of 64 years old, one of 33 and one of 76 years old. More than twenty cases of tendinitis have previously been described in the literature in association with pefloxacin and various other fluoroquinolone derivatives; tendon rupture was a frequent complication. In the data base of the WHO Collaborating Centre for International Drug Monitoring tendon disorders are a very rare reaction, with the exception of fluoroquinolone derivatives. More information is needed with regard to the frequency of tendinopathy during the use of pefloxacin and the other drugs in this group. Achilles tendon rupture is an serious condition, often requiring surgical treatment. Patients using a fluoroquinolone derivative should be informed of the risk of developing tendinitis and tendon rupture.

Achilles Tendon↗
PubMed1994

Diffusion of digital radiology modalities in the Nordic countries and Japan.

The Nordic countries have 23 million inhabitants. About 14 million radiology examinations are performed annually at hospitals and in primary health care. This represents about 600 examinations per 1000 inhabitants per year. Japan, on the other hand, has 125 million inhabitants and annually performs about 200 million radiology examinations at hospitals and in primary health care. This represents about 1600 examinations per 1000 inhabitants per year. The above figures do not include dental X-ray examinations. Between 15% and 20% of all radiology examinations in the Nordic countries and about 5% in Japan are performed with digital modalities such as computerized tomography, digital subtraction angiography, computed radiography, and magnetic resonance imaging. Computerized tomography is the most diffused digital X-ray modality in the Nordic countries with 95,000 inhabitants per scanner while Japan only has 17,000 inhabitants per scanner. For magnetic resonance imaging the difference is almost of the same order. Japan has the same diffusion of magnetic resonance imaging units per 100,000 inhabitants as the Nordic countries have of computerized tomography scanners. The large difference between Japan and the Nordic countries regarding diffusion of digital radiology modalities is explained mainly by differences in the nature and organization of radiology services.

Diagnostic Imaging↗
PubMed1994

Effect of dofetilide on cardiac repolarization in patients with ventricular tachycardia. A study using simultaneous monophasic action potential recordings from two sites in the right ventricle.

Monophasic action potentials (MAP) were simultaneously recorded from the right ventricular (RV) apex (RVA) and the outflow tract (RVOT) before and after an infusion of dofetilide in 10 patients with documented ventricular tachycardia. After the drug infusion, the MAP duration (MAPd), repolarization time, and corrected QT interval were significantly prolonged during sinus rhythm, RV pacing, and RV extra stimulation. The prolongation of MAPd at 90% repolarization during RV pacing at a cycle length of 500 ms was 31 +/- 6 ms (13%) and 26 +/- 7 ms (11%) at RVA and RVOT, respectively. The ventricular effective refractory period was significantly prolonged by 33 +/- 9 ms (13%) and 22 +/- 7 ms (9%) at driving cycle lengths 600 and 500 ms, respectively. The MAPd shortening with decreasing diastolic time intervals was significantly diminished by dofetilide in early extra beats during RV extra stimulation, suggesting a relatively more pronounced effect of this drug at the early diastolic phase. The dispersion of repolarization, defined as the difference in MAPd between RVA and RVOT, and the activation time were not significantly changed. In conclusion, acute administration of dofetilide in patients with ventricular tachycardia significantly prolonged the time intervals of ventricular repolarization and refractoriness in a parallel fashion, without affecting intraventricular conduction. The effect of dofetilide on MAPd prolongation appeared not to be reverse use-dependent in this study in humans. These results verify the selective class III antiarrhythmic property of dofetilide and warrant further studies in patients.

Action Potentials↗