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Biomedical subjects

G Lindgren

Publications and source records attributed to G Lindgren.

At least 73 records · Page 4Linked to original sources
PubMed1985

Model for the study of the preeruptive effect of NaF tablets on caries in permanent teeth.

The purpose of this study was to elaborate a model for estimating the caries-reducing effect of a preventive measure with due consideration of background factors. The material comprised 50 children, who had consumed NaF tablets regularly during preschool age, and 76 comparable children who had never consumed NaF tablets. They were all examined at 12 and 13 yr of age. Information on caries and, as confounding factors, dietary habits, oral hygiene and microbiologic variables, was obtained on both occasions. Correlations between the parameters and caries, their discriminating effects and interaction between them were studied. The results showed that correction for confounding diminished the crude caries-reducing effect of NaF tablets. Streptococcus mutans and lactobacilli turned out to be the strongest confounders to discriminate well as single variables and to behave logically in analyses of interaction. Therefore, these factors are recommended in the first place for inclusion in a correction model. If the material is sufficiently large for a further breakdown, oral hygiene (represented by bleeding on probing) could be added. The model will be used in future studies of the preeruptive effect of NaF tablets on caries in permanent teeth in the same population.

Adolescent↗
PubMed1985

Acetylcholinesterase inhibition by sulphur and selenium heterosubstituted isomers of N,N-diethylcarbamyl choline and carbaryl.

Nine sulphur and selenium heterosubstituted isomers of N,N-diethylcarbamylcholine and carbaryl have been prepared and their inhibiting activity towards electric eel acetylcholinesterase (E.C. 3.1.1.7) have been measured. The N,N-diethylcarbamylcholines acted only as reversible inhibitors, i.e. they could not carbamylate the enzyme. The reversible inhibition was of mixed type. Sulphur and selenium substitution had only marginal effects on Ki(0.2-0.3 mM) but reduced the value of K'i. The heterosubstituted carbaryl analogues were, with one exception, found to be irreversible inhibitors, about 100 times less potent than carbaryl.

Animals↗
PubMed1984

Hb-Linköping (beta 36 Pro----Thr): a new hemoglobin mutant characterized by reversed-phase high-performance liquid chromatography.

Preparative separation of alpha- and beta-chains from a newly identified abnormal hemoglobin has been performed on a new C1/C8 column. Tryptic peptides from the abnormal beta-chain were subjected to peptide mapping on a new C2/C18 column with a reversed-phase system including potassium dihydrogen phosphate (pH 2.9) as a hydrophilic ion-pairing reagent. A hydrophobic substitution, beta 36 proline-threonine, was evident after amino acid analysis and Edman degradation of the isolated mutant peptide. Replacement of proline as the second amino acid in the C-helix represents an important structural change in the alpha 1 beta 2-contact.

Amino Acids↗
PubMed1981

Alternative surfaces for microcarrier culture of animal cells.

As part of an effort to broaden the applicability and efficiency of microcarrier cell culture various alternative new microcarriers were synthesized. The microcarriers were compared as substrates for the growth of several types of cells and with respect to binding of proteins from the culture medium. Cross-linked dextran has been found to be the most suitable material for a microcarrier matrix and was used as the matrix for the new microcarriers. One type of microcarrier was synthesized so that the charges necessary for cell attachment were present only in the surface layer of the microcarrier in the form of N,N,N-trimethyl-2-hydroxyaminopropyl groups. The resulting microcarriers had a very low capacity to bind proteins from the culture medium (e.g. albumin and IgG) and such proteins could be removed from the cultures more efficiently than when using previous microcarriers. A new principle was used for the development of the other type of microcarrier. A surface layer of cross-linked denatured collagen provided the surface for growth of cells. These microcarriers provided a "natural" substrate for cell growth and allowed improved attachment and spreading of cells with epithelial morphology. Harvesting cells from these microcarriers with proteolytic enzymes was more efficient than with previous microcarriers. The two alternative microcarriers should result in improved process efficiency and have a potential value in the preparation of live vaccines.

Animals↗
PubMed1980

Microcarriers for animal cell culture: a brief review of theory and practice.

Microcarrier beads for animal cell culture are considered in relation to aspects of cell adhesion and growth. Some "critical parameters" for a successful microcarrier are discussed, comparing currently available materials. The properties most critical for a successful microcarrier were closely fulfilled by the microcarrier CytodexTM 1 which has been used for the successful cultivation of more than 60 different cell types. Cytodex 1 has been used for the culture of primary cells, normal diploid cell strains and established or transformed cell lines in culture volumes ranging from a few millilitres to over 100 litres.

Animals↗
PubMed1979

Clinical and arthrographic studies on the valve mechanism in communicating popliteal cysts.

Forty-one knee joints presenting with significant popliteal cysts were examined clinically and arthrographically. The fluid was aspirated from the cysts and replaced by contrast medium of low viscosity. On knee flexion the contrast fluid spontaneously passed over into the joint in 16 cases (no valve mechanism), in 7 small amounts of fluid were forced into the joint when the cysts were manually compressed, and in 18 no fluid passage to the joint was observed on manipulation (valve mechanism). When a valvular action was established, effusion in the joint was rare and the fluid from the cyst was usually viscous. The cysts with a valvular connection were significantly larger than those without a valve mechanism.

Adult↗
PubMed1978

Growth of schoolchildren with early, average and late ages of peak height velocity.

A sample of Swedish urban schoolchildren (357 girls, 373 boys) born in 1954/55 followed from 10 to 18 years were grouped according to peak height velocity age (PHV age) into early, average and late maturers. Mean heights differed between the maturity groups at ages from 10.0 to 14.0 years for girls and 10.5 to 17.0 years for boys. Mean weights differed between the maturity groups at all ages up to 16.0 years for girls and up to 18.0 years for boys. The earlier the maturity process, the heavier for given height. The time differences between peak weight velocity (PWV) and PHV significantly differed between early, average and late maturers amounting to 0.9, 0.5 and 0.2 years respectively for girls and 0.6, 0.3 and -0.1 years respectively for boys. The time difference between menarche and PWV did not differ between the maturity groups and amounted to about 0.6 +/- 0.05 years (SD = 0.9). For boys a similar lack of difference between maturity groups was obtained concerning the time difference between secondary sex characteristics; stage 4 (SSC IV) and PWV. Mean height and weight for girls and boys differed between the maturity groups at PHV but not at PWV, menarche or SCC IV.

Adolescent↗
PubMed1977

A comparison of growth in twins and singleton controls of matched age followed longitudinally from 10 to 18 years.

A sample of 323 pairs of twins (94 MZ pairs, 133 DZ like-sexed pairs and 97 DZ unlike-sexed pairs born in 1954/55) were studied longitudinally from 10 to 18 years for boys and 10 to 16 years for girls. Height, weight, age at menarche and peak height and weight velocities (PHV and PWV) were studied. No significant differences occurred between twin categories in any two of these varieties, so in each sex the total twin group was compared with a group of matched singleton controls (380 boys and 360 girls). There were very small differences between the twin boys and their controls in height, weight and PWV-age. PHV occurred somewhat earlier in twin boys than in the controls. The height and weight peaks were significantly lower for the twin boys. For twin girls, however, a height and weight deficit was found during puberty and they also matured a little later than their controls according to both PHV, PWV and menarche. The height and weight peaks were also somewhat lower for the twin girls. One reason for the observed sex differences could be a proportionally higher mortality for twin boys, thus an effect of selective survival.

Adolescent↗
PubMed1977

Effects of a health screening on mortality and causes of death in middle-aged men. A prospective study from 1970 to 1974 of mean in Malmö, born 1914.

All men born in even-numbered months in 1914 and domiciled in Malmö were invited in 1969 to participate in an investigation regarding risk factors for cardiovascular disease. Individuals with a blood pressure of 165/110 and over were treated and a sub-sample of heavy smokers were later invited to take part in a quit-smoking project. During the following five year period total and cause-specific mortality in the examined group was compared with corresponding data for men born in uneven months in 1914. Mortality in the examined cohort was lower than among controls and differed significantly from that in the control group with regard to cardiovascular mortality.

Cardiovascular Diseases↗
PubMed1976

Height, weight and menarche in Swedish urban school children in relation to socio-economic and regional factors.

During the period 1964-1973, a defined sample of 740 Swedish urban school children (360 girls and 380 boys) from 40 different urban areas all over the country were followed longitudinally. Height and weight were measured twice a year and age at menarche was recorded. Mean ages at peak height velocity (PHV) and peak weight velocity (PWV) were 11-91 years (SD 0-95) and 12-50 years (SD 1-08) for girls with average values of 8-30 cm/year (SD 1-32) and 7-37 kg/year (SD 1-94). Mean age at menarche was 13-05 years (SD 1-03). PHV and PWV in boys occurred on average at 14-09 years (SD 1-11) and 14-30 years (SD 1-11) with magnitudes of 9-84 cm/year (SD 1-40) and 9-07 kg/year (SD 2-04). No significant differences between socio-economic strata defined by father's occupation and family income were found either for height and weight or for ages at PHV, PWV and menarche. Girls but not boys in the lowest social group (III) had more weight for height during puberty than had girls in social groups I and II. Between the three main geographical regions of Sweden some differences were found. Boys in the South were at the ages of 17 and 18 on average heavier than boys from the rest of the country. Boys and girls in the South had PHV, PWV and menarche half a year later than children in Middle Sweden. In analysis of variance for age at PHV significant interaction terms were found for regions times urbanization. In the South and North age at PHV was earlier the higher the urbanization level, but in Middle Sweden the reverse occurred.

Adolescent↗