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Biomedical subjects

G Jönsson

Publications and source records attributed to G Jönsson.

At least 19 recordsLinked to original sources
PubMed2001

Studies of the radon concentration in drinking water from the horst Söderåsen in southern Sweden.

The radon activity concentration in ground water from drilled and dug wells on the horst Söderåsen in Southern Sweden has been determined with two different methods, gamma activity measurements with a germanium HPGe detector and alpha activity measurements with plastic track detectors. The results are consistent. High activity concentration is connected to granite bedrock. Dug wells have low concentrations and no trivial correlation between concentration and depth of the well is found. Large local variations exist. Activity concentrations > 700 Bq/l appear to be associated with leakage from layers of volcanic origin. The concentration from drilled wells is found to be quite constant over a 3 year period but short time variations appear to be significant. Evaporation from the open surface of a normal cooking vessel is slow with an activity gradient delta A/A of about 0.1-0.2 per hour at room temperature whereas even modest heating of water in e.g. a coffee machine is very efficient and reduces the radon activity concentration by > 90% in one process.

Radon↗
PubMed2000

Frequency of penicillin-resistant pneumococci in children is correlated to community utilization of antibiotics.

OBJECTIVE: To study the impact of the utilization of antibiotics in children at the population level on the frequency of penicillin-nonsusceptible pneumococci (PNSP). DESIGN: Children ages 0 to 6 years with a nasopharyngeal culture of PNSP were registered on place of residency in the 20 municipalities of the former Malmöhus County (since 1998 a part of Skåne County). Where possible the total number of nasopharyngeal cultures with growth of pneumococci was registered as well. All antibiotic prescriptions for 0- to 6-year-old children were analyzed in the 20 municipalities. MAIN OUTCOME MEASURES: Correlation between the utilization of antibiotics and the frequency of PNSP in children at the municipality level. RESULTS: The proportion of PNSP among all isolates of pneumococci from nasopharyngeal cultures varied between 0 and 49.5%. The antibiotic utilization in children varied among the 20 neighboring municipalities from 8.5 to 19.7 defined daily doses per 1000 children per day. The municipalities with high total utilization also had more frequent use of macrolides and broad spectrum antibiotics. The was a significant correlation between antibiotic use and the proportion of PNSP (correlation coefficient, 0.96; P = 0.002), and the correlation coefficients for trimethoprim-sulfamethoxazole, amoxicillins, macrolides and cephalosporins were significant at the 0.001 level. There was no significant correlation between the use of penicillin V and the frequency of PNSP. CONCLUSIONS. There was a significant correlation between the frequency of PNSP and the utilization of antibiotics in children at the population level.

Anti-Bacterial Agents↗
PubMed2000

Cellular changes and apoptosis in the spleens and peripheral blood of mice infected with blood-stage Plasmodium chabaudi chabaudi AS.

Infection with blood-stage Plasmodium chabaudi chabaudi AS results in splenomegaly, peripheral leukocytosis, and a major activation of the immune system. The frequencies and absolute numbers of T-cell, B-cell, and macrophage populations in spleen and peripheral blood from P. chabaudi-infected BALB/c mice were compared and found to be significantly altered during acute infection. The kinetics of the redistribution of the different cell types in spleen and peripheral blood were different, with T and B cells appearing in the blood when their frequencies and absolute numbers in the spleen were low. The frequency and absolute number of apoptotic cells in the spleen were increased during acute P. chabaudi infection and involved both T cells, B cells, and macrophages. Both Fas and Fas-ligand expression were increased in the spleen. Taken together, our data provide new information on the complex cellular interactions that take place in the immune system during blood-stage malaria infection in a mouse model.

Acute Disease↗
PubMed1998

Stimulation of CD40 in human bladder carcinoma cells inhibits anti-Fas/APO-1 (CD95)-induced apoptosis.

CD40 and the CD95 (Fas/APO-1 antigen) are both members of the tumor necrosis factor receptor family. Whereas CD40 mediates a strong growth stimulatory signal in B cells, engagement of the CD95 receptor leads to growth inhibition and induction of apoptosis. As it has been reported that CD40 activation may rescue B cells from undergoing apoptosis, we were interested to see whether it had a similar effect in other cells expressing the CD40 receptor. We used epithelial tumor cells from the urinary bladder, a cell type that frequently expresses CD40 but for which no clear function of the molecule has been assigned. We found that the ligation of CD95 with the antibody anti-APO-1 induced apoptosis in most of the cell lines tested. Stimulation of CD40 with antibodies or a soluble construct of the CD40 ligand was shown to protect cells from apoptosis, as demonstrated by their ability to suppress the growth inhibition exerted by the anti-APO-1 antibody. Our results show that CD40 stimulation make cells less vulnerable to apoptosis induced via CD95 and suggest that CD40 expression on epithelial tumors may be associated with cell survival.

Animals↗
PubMed1998

The use of a conical fixture design for fixed partial prostheses. A preliminary report.

A specially designed, TiO2-blasted titanium fixture, partially conical and microthreaded, the Astra Tech Fixture ST, was used for rehabilitation of partial edentulism in the posterior mandible. Superior to the mandibular canal 25 fixtures were placed in 10 patients. Fixed metal-ceramic bridges were then performed. After 1-year follow-up, all bridges were found to be clinically stable. The implant survival rate was 100% and the mean marginal bone resorption was 0.05 +/- 0.11 mm.

Aged↗
PubMed1996

Phosphorous carbohydrates on chimeric CD22, CD44 and CD62L.

There are few examples of phosphorous carbohydrates described in higher animals. Here we have used recombinant molecules where the extracellular part of membrane receptors have been fused with the Fc part of human IgG (Rg-chimeras) to look at the prevalence of phosphorous carbohydrates. Also chimeras of a few hormones were used in this study. Thirteen Rg constructs were transfected into Cos cells and labelled with [32P]orthophosphate in phosphor deficient media. These Rg molecules were subsequently purified on protein A-Sepharose and submitted to SDS-PAGE and radiography. CD22Rg, CD62L-Rg and CD44Rg were all labelled very strongly with 32P. From CD22Rg and CD62L-Rg the label could be easily removed by N-glycosidase F, but the 32P label on CD44Rg was resistant to N-glycosidase treatment. However, after treatment with O-glycosidase combined with sialidase, CD44Rg retained only a fraction of the 32P. Weakly phosphorylated Rg molecules were CD62E-Rg and CD7Rg. However, CD7Rg did not seem to loose the label, only shift position after N-glycosidase treatment and CD62E-Rg did neither shift position nor loose any 32P label after the N-glycosidase treatment. Negative chimeras were CD40Rg, CD33Rg, Lamp-1Rg, CD34Rg, ICAM-1Rg, TNF alpha Rg, CD19Rg and CD5Rg. The phosphate label of CD22Rg was completely removed after ALP treatment and in CD44Rg most of the label was removed. ALP is not supposed to cleave phosphodiesterbonds leading to the conclusion that the phosphor is likely present in the form of phosphomonoesters. This result is interesting as alkaline phosphatase (ALP) is common on the outer cellsurface of many cell types and might interact with phosphorous carbohydrates on membrane proteins. The membrane from of CD22 was also transfected into Cos cells and labelled with 32P in phosphate free media. Subsequently the cells were lysed and CD22 affinity purified and analysed by SDS-PAGE and radiography. Under these conditions CD22 was shown to be 32P labelled, but only 20% of the label was removed by N-glycosidase F treatment. These results do not show that CD22, CD44 and CD62L are phosphorylated on carbohydrates under more physiological circumstances, but they do show that phosphorous carbohydrates might be more common in higher animals than what was been reported.

Antigens, CD↗
PubMed1995

Intestinal microbial bile acid transformation in healthy infants.

Following the establishment of functionally active intestinal flora in three healthy Swedish children from birth up to 24 months of age, we investigated the development of different 24-carbon bile acids. The fecal bile acids were group-separated into unconjugated, glycine-conjugated, taurine-conjugated, and sulfated, so that we could follow the changes between the different fractions of conjugates. In meconium, most (55-63%) of the bile acids were conjugated with taurine; only 11-32% were conjugated with glycine. Deconjugation was the first sign of intestinal microbial activity on the bile acids. Already at 1 month of age, most of the bile acids were deconjugated; among the conjugated bile acids, the glycine-conjugated dominated over the taurine-conjugated. An unidentified conjugate of cholic and chenodeoxycholic acids (C, CDC) that separated with the sulfated bile acids was found. The unconjugated bile acids and those that arose from hydrolysis of existing conjugates were separated and identified by gas-liquid chromatography coupled to mass spectrometry (GC-MS). Twenty-nine different bile acids were identified. In meconium, 16 different bile acids were identified. C and CDC were identified in all samples. The bile acid pattern changed during the course of the study. Many of the identified bile acids were only found in one or a few of the analyzed samples, and sometimes only in samples from one child. 6 alpha-hydroxylated bile acids, probably not microbially synthesized, were present at high percentages in the children.(ABSTRACT TRUNCATED AT 250 WORDS)

Bifidobacterium↗
PubMed1995

Budesonide is metabolized by cytochrome P450 3A (CYP3A) enzymes in human liver.

Budesonide is a synthetic glucocorticosteroid that is commonly used in topical treatment of asthma and rhinitis. The main metabolites formed from budesonide in human liver microsomes have been identified as 16 alpha-hydroxyprednisolone and 6 beta-hydroxy-budesonide. Although it is apparent that the cytochrome P450 (CYP) system is involved, the actual subfamily has not been identified. In attempts to do this, budesonide was incubated with microsomes from ten different human liver samples where various CYP activities had been rank ordered. We found a strong correlation between formation of the two main metabolites and testosterone 6 beta-hydroxylation (correlation 0.98 and 0.95), a marker for CYP3A. When budesonide (10 microM) was incubated with human liver microsomes in the presence of compounds known to interact with different isoforms or subfamilies of CYP, ketoconazole was found to be the strongest inhibitor of budesonide metabolism (IC50: approximately 0.1 microM) followed by troleandomycin (IC50: approximately 1 microM), erythromycin, and cyclosporin, all substances known to interact with CYP3A isoenzymes. Substances known to interact with CYP2C (sulfaphenazole, mephenytoin, and tolbutamide) and with CYP2D6 (bufuralol and quinidine) did not specifically inhibit the metabolism of budesonide. In addition, formation of the budesonide metabolites (16 alpha-hydroxyprednisolone and 6 beta-hydroxybudesonide) was inhibited by antibodies against the CYP3A subfamily, but not by antibodies against the CYP1A subfamily or control immunoglobulin G. We conclude that the formation of 16 alpha-hydroxyprednisolone and 6 beta-hydroxybudesonide from budesonide is catalyzed by isoenzymes within the CYP3A subfamily.

Administration, Topical↗
PubMed1994

Concentrations of sodium, potassium, calcium, magnesium and chlorine in the muscle cells of downer cows and cows with parturient paresis.

The concentrations of sodium, potassium, calcium, magnesium, phosphorus, sulphur and chlorine, in the skeletal muscle fibres of cows with parturient paresis, downer cows, normally calving cows and unmated heifers were determined by means of an X-ray microanalysis technique. The most consistent finding was an increase in the concentration of chlorine in the muscle samples from the downer cows. There were no other significant differences between the concentrations of these elements in samples from the different groups of cows, but the calcium concentration was higher in the muscle samples collected one month after parturition than in the samples collected close to parturition.

Animals↗
PubMed1993

Indoor radon-daughter concentration and gamma radiation in urban and rural homes on geologically varying ground.

The radon (Rn)-daughter level (track film, 3 months) was lower in 129 urban than in 197 rural houses (geometric means, (GM) 18 versus 40 Bq/m3; P < 0.001; range 3-416). In rural dwellings higher levels were found in those built over deposits of alum shale occurrences (P = 0.04; 12 on porous glaciofluvial cover 94 Bq/m3; 127 others 43 Bq/m3; significant interaction, P = 0.01), than in 158 others (37 Bq/m3). There was no systematic effect of the type of water supply, neither of indoor smoking. One hundred twenty three homes with a complete cellar were lower than 200 with no or part cellar (18 versus 40 Bq/m3; P < 0.001). There was only a weak association between log-transformed gamma radiation (GM 10, range 33-50 microR/h) and Rn-daughter levels (r = 0.18; 95% confidence interval 0.07-0.28). Our results show the importance for indoor Rn-daughter levels of the bedrock and cover beneath the house, and the need for Rn-daughter measurements in epidemiological studies.

Air Pollution, Indoor↗
PubMed1993

Ultrasonography and determination of proteins and enzymes in blood for the diagnosis of liver abscesses in intensively fed beef cattle.

The concentrations of plasma proteins and the activities of liver enzymes were measured every 2 weeks from weaning to slaughter in 21 beef cattle, and their livers were examined ultrasonographically every 4 weeks. Eight of the 9 cases of single or multiple liver abscesses were detected by ultrasonography but some individual abscesses, particularly those in the left side of the liver, remained undetected. The time at which the abscesses were first detected ranged from 4 to 20 (mean 12.5) weeks. There were only slight variations in the blood constituents and they were of no significant value in the diagnosis of the liver abscesses.

Animal Feed↗
PubMed1992

Serum concentrations and excretion of bile acids in cirrhosis.

Bile acid concentrations in serum, and urinary and faecal excretion of bile acids have been studied in ten patients with liver cirrhosis as a consequence of alcohol abuse. Eight of the patients were categorized as Child group A, whereas the remaining two patients comprised Child group C. Individual bile acids were isolated and identified by gas chromatography coupled to mass spectrometry. Total fasting serum bile acid concentrations were elevated in all patients, but not correlated to conventional tests of liver function. Eight of the patients had increased urinary excretion of bile acids. Faecal bile acid-excretion was highly variable between patients, and also between Child's group A and C patients. Total fasting serum bile acid concentrations were not correlated to either urinary, faecal, or total bile acid excretion (= synthesis of bile acids) or to the ratio between urinary and faecal excretion of bile acids. The daily synthesis of bile acids showed a large overlap between Child's group A and C patients. The percentage of chenodeoxycholic acid and its metabolites relative to total daily excretion of bile acids did not correlate, indicating that the synthesis pathways for the primary bile acids does not systematically change in relation to the rate of synthesis. We conclude that even in mild cirrhosis, serum bile acid concentrations are elevated. However, no consistent changes in synthesis of bile acids or synthesis pathways was observed in such patients.

Adult↗
PubMed1992

Approximal caries and frequency of bitewing examinations in Swedish children and adolescents.

The aim of this study was to assess the number of, and time intervals between, bitewing examinations performed on a group of Swedish patients between 3 up to and including 18 yr of age and to relate them to the accumulated posterior approximal caries experience of the patients as found in the last bitewing examination before age 19. The patients showed a marked variability in approximal caries experience. 25% accounted for about 1% of the total number of carious lesions and restorations accumulated up to age 19 while 25% accounted for 60%. From age 9 up to age 18 more than 75% of the patients were subjected to at least one bitewing examination annually. Between 10 and 15 yr of age more than 90% received annual radiographic examinations. Mean number of bitewing examinations was 10.4 and the average time interval between bitewing examinations was 11.5 months. 11% of the variation in the number of bitewing examinations and 8% of the variation in average time intervals between bitewing examinations could be explained by the number of lesions and restorations in the approximal surfaces of the patients accumulated up to age 19.

Adolescent↗
PubMed1992

Presence of bile acid metabolites in serum, urine, and faeces in cirrhosis.

Studies have been made of the presence of bile acid metabolites in ten patients with liver cirrhosis as a consequence of alcohol abuse. Eight of the patients were categorized as Child group A, indicating only mild impairment of liver function, whereas the remaining two patients comprised Child group C. A complex mixture of bile acids was isolated from serum, urine, and faeces, and 26 bile acids were identified by gas-liquid chromatography coupled to mass spectrometry. Identification was made of the primary bile acids, cholic (C) and chenodeoxycholic (CDC) acid, and metabolites of these bile acids converted through 7-dehydroxylation, keto-formation, 6-hydroxylation, 1 beta-hydroxylation, allo-formation or nor-formation. All of the bile acids have previously been described either in healthy humans or patients with hepatobiliary disease. With the exception of C, CDC, and deoxycholic acid, all of the bile acids were present only infrequently, and none of the bile acids was pathognomonic for liver cirrhosis. The proportion of metabolites of the primary bile acids C and CDC was similar to that previously reported in healthy humans, the lowest proportion being recorded in the Child group C patients. Repeated determinations of the metabolite pattern in two patients showed large variations, indicating that the bile acid metabolism varies from time to time. We conclude that in mild cirrhosis, no significant alterations in microbial or hepatic transformation of bile acids seem to occur.

Bacteria↗
PubMed1991

Equilibration of labelled and endogenous bile acids in patients with liver cirrhosis after administration of (24-14C)cholic and chenodeoxycholic acids.

On separate occasions (24-14C)cholic acid and (24-14C)chenodeoxycholic acid were administered intravenously to patients with liver cirrhosis and the isotope excretion in urine and faeces monitored. Bile acids in serum, urine and faeces were extracted and separated into unconjugated bile acids, glycine- and taurine conjugates, glucuronides and sulphates. Individual bile acid conjugates were separated by high-performance liquid chromatography (HPLC) and the unconjugated bile acids were separated by gas-liquid chromatography (GLC) and identified by gas chromatography-mass spectrometry (GC-MS). Individual bile acid conjugates were quantified and their isotope contents determined. In serum, isotope contents declined rapidly during the first day, followed by a markedly slow rate of reduction. In accordance with this, the excretion of isotope from the patients was found to be very slow and the routes of bile acid excretion were changed, which resulted in an increased ratio of urine/faeces isotope excretion. Studies of the ratio of labelled to endogenous bile acid conjugates indicated that a continuous transformation of the labelled compounds occurred during the period of study. As judged from serum bile acids, conjugation to glycine- or taurine conjugates was rapid. The specific activities of labelled sulphate esters were consistently lower than for other conjugates during the 300-min observation period. During the first day, the urinary bile acids contained a high proportion of unconjugated labelled bile acids, which gradually disappeared. Labelled primary bile acids were slowly converted into microbial products, mainly 7-alpha dehydroxylated derivatives. The observed slow transformations resulted in a much delayed equilibration of labelled and endogenous bile acid derivatives, which invalidates isotope techniques for calculation of kinetic data of bile acid turnover. However, the observed very slow turnover of labelled bile acids in cirrhosis, owing to the persistent high rate of intestinal absorption and low capacity for urinary excretion, makes it possible for the intestinal flora to markedly change the composition of the bile acids in the pool. Studies of endogenous urinary and faecal bile acid excretion revealed the changed route of bile acid excretion with a high urinary/faeces ratio and the decreased synthesis of bile acids in cirrhosis.

Bile Acids and Salts↗
PubMed1991

Caries-inhibiting effects of different modes of Duraphat varnish reapplication: a 3-year radiographic study.

One hundred and sixty 11-year-olds were randomly allocated to two experimental groups, one test (group 1) and one control group (group 2), for a 3-year clinical test comparing different modes of fluoride varnish treatment. In the test group, children received Duraphat varnish treatments 3 times a week, once a year. The children in group 2 were treated with Duraphat every 6 months. During the experimental period, children in group 1 received 9 fluoride varnish applications, and in group 2, 6 applications. Four bitewing radiographs were taken in each child each year for the measurements of the incidence and progression of proximal caries. Repeated fluoride varnish treatment with Duraphat, 3 times a week once a year, appears to inhibit proximal caries progression and development since the children in this group showed even a lower caries status, 1.3 +/- 0.3 DS, at the end of the study compared to 1.6 +/- 0.2 DS at the outset. In group 2, the children increased their caries status from 1.7 +/- 0.2 to 2.4 +/- 0.4 DS during the experimental period. The caries difference was statistically significant (p less than 0.05) between the two groups. A health economic comparison of the two modes of application showed 30% lower costs for the children in the test group based on time used for preventive measures and assumed filling therapy.

Child↗
PubMed1991

Caries-preventive effect of dentifrices containing various types and concentrations of fluorides and sugar alcohols.

The caries-inhibiting effect of unsupervised daily use of four different toothpastes was compared in a 3-year clinical and microbiological study: (1) 0.8% sodium monofluorophosphate (MFP) with 3% xylitol and 6% sorbitol; (2) 0.03% sodium fluoride with 3% xylitol and 6% sorbitol; (3) 0.8% MFP with 9% sorbitol, and (4) 0.03% sodium fluoride with 9% sorbitol. In all 284 children, 12-13 years old at baseline, took part in the study. After 3 years, no statistically significant differences were found between the different toothpaste groups concerning either development of initial or gross caries lesions or number of mutans streptococci and lactobacilli in saliva. However, children with no detectable approximal caries at baseline, who used the MFP toothpaste with the xylitol-sorbitol mixture, showed a lower (p less than 0.05) caries increment as compared with children who used the MFP toothpaste with sorbitol alone.

Adolescent↗