Search PubMed⌕ Search

Biomedical subjects

B Laursen

Publications and source records attributed to B Laursen.

At least 37 records · Page 2Linked to original sources
PubMed1998

Reconsidering changes in parent-child conflict across adolescence: a meta-analysis.

A series of meta-analyses addresses whether and how parent-child conflict changes during adolescence and factors that moderate patterns of change. The meta-analyses summarize results from studies of change in parent-child conflict as a function of either adolescent age or pubertal maturation. Three types of parent-adolescent conflict are examined: conflict rate, conflict affect, and total conflict (rate and affect combined). The results provide little support for the commonly held view that parent-child conflict rises and then falls across adolescence, although conclusions regarding pubertal change as well as conflict affect are qualified by the limited number of studies available. Two diverging sets of linear effects emerged, one indicating a decline in conflict rate and total conflict with age and the other indicating an increase in conflict affect with both age and pubertal maturation. In age meta-analyses, conflict rate and total conflict decline from early adolescence to mid-adolescence and from mid-adolescence to late adolescence; conflict affect increases from early adolescence to mid-adolescence. Puberty meta-analyses revealed only a positive linear association between conflict affect and pubertal maturation. Effect-size patterns varied little in follow-up analyses of potential moderating variables, implying similarities in the direction (although not the magnitude) of conflict across parent-adolescent dyads, reporters, and measurement procedures.

Adolescent↗
PubMed1994

Three novel missense mutations in the antithrombin III (AT3) gene causing recurrent venous thrombosis.

The polymerase chain reaction and direct sequencing were used to determine the nature of the mutations in the antithrombin III (AT3) gene in seven unrelated patients with familial antithrombin III (ATIII) deficiency and recurrent venous thrombosis. Three novel mutations were found, two associated with a type I deficiency state (Pro80-->Thr and His120-->Tyr) manifesting reduced synthesis of ATIII. The other novel lesion (Met251-->Ile) was associated with a dysfunctional ATIII protein (type II ATIII deficiency) and is predicted to interfere either with a heparin-induced conformational change in the ATIII molecule or with docking to thrombin. A novel polymorphism (Tyr158-->Cys) was also found to occur in several individuals of Scandinavian origin.

Amino Acid Sequence↗
PubMed1994

Interpersonal conflict during adolescence.

Interpersonal conflict is considered within various frameworks of adolescent development. Conflict, defined as behavioral opposition, is distinguished from related constructs. Differences between adolescent relationships and across age groups are reviewed in the incidence and intensity, resolution, and outcome of conflict. Influences of setting on conflict behaviors and effects are emphasized. The evidence does not reveal dramatic shifts in conflict behavior as a function of age or maturation. Consistent differences do emerge, however, when adolescent relationships and conflict settings are considered. It is argued that a social relational model based on principles of interdependence and equity provides an alternative to psychoanalytic, sociobiological, and cognitive-developmental accounts of conflict behavior during adolescence.

Adolescent↗
PubMed1993

A national cross-sectional study of the working environment in the Danish wood and furniture industry--air pollution and noise.

A cross-sectional survey was carried out in the Danish wood and furniture industry at 200 factories. In this paper, representative estimates of employees' full-shift exposures to wood dust, vapours from organic solvents, formaldehyde and noise dose were calculated using a model for two-stage cluster designs. Exposures to air pollutants were generally below the occupational exposure limits (OELs), while noise doses were at the same level as OEL. The overall exposure to wood dust was 0.90 mg m-3, exposure to vapours from organic solvents was 0.13 C/OEL and noise dose, Leq (8 h), was 90.5 dB(A).

Air Pollutants, Occupational↗
PubMed1993

Conflict and friendship relations in middle childhood: behavior in a closed-field situation.

Disagreements between school-aged children were examined as a function of friendship status. 66 same-sex dyads were selected, including equal numbers of "best friends" and nonfriends, who were then observed while playing a board game (a closed-field situation). Conflicts occurred more frequently among friends than among nonfriends and lasted longer. Friends did not talk more during their conflicts than nonfriends, but assertions were used selectively according to friendship and sex: With friends, girls used assertions accompanied by rationales more frequently than boys whereas boys used assertions without rationales more frequently than girls. These sex differences were not evident during conflicts between nonfriends. Results are discussed in relation to the social constraints intrinsic to closed-field competitive conditions as they apply to friendship relations in middle childhood.

Child↗
PubMed1993

Availability of data on humans potentially exposed to suspected carcinogens in the Danish working environment.

For the majority of suspected carcinogens only little or no human evidence exists, and in general on-going epidemiologic studies fail to address this fast growing group of chemicals. A survey based on a Danish occupational surveillance system concerning data on present and historical import, production and use of the 167 chemicals evaluated by the International Agency for Research on Cancer as possible or probable carcinogens, shows that about 110 of these chemicals are on the market in Denmark at present. Only 32 are used in industry in relatively large quantities. For some of these chemicals it is possible to identify clusters of companies, including historical cohorts of potentially exposed workers. Measurements of airborne pollutants are available for some few of the suspected carcinogens, indicating decreasing time trends and various levels in different industries. In spite of some limitations, this information on potential exposure has on ad hoc basis been linked to an existing cancer registry based occupational surveillance system, and various studies based on the total body of data are on-going, as a preliminary approach to give at least some human evidence to some widespread animal carcinogens.

Carcinogens, Environmental↗
PubMed1992

[The post-thrombotic syndrome. A review].

The post-thrombotic syndrome which is caused by deep venous thrombosis and characterized by pain, oedema, pigmentation, eczema, lipodermatosis, varices and ulceration, is due to deficient function of the venous valves and/or obstruction of the deep veins with venous hypertension. The diagnosis may be established by investigation of the investigation of the muscular-venous pump by pletysmography or dynamic phlebography and invasive measurement of the venous pressure is not employed to any great extent. The results of valvuloplasty have, by and large, been negative. The main form of treatment is, therefore, conservative compressive bandaging which can reduce the symptoms, facilitate healing of venous ulcers and prevent recurrence of ulcers. It is emphasized, however, that this treatment must be continued consequently during the remainder of the patient's life, regardless of other treatment.

Humans↗
PubMed1992

[The post-thrombotic syndrome. Description and comparison of diagnostic methods: clinical examination, venous return time, phlebography and ultrasonography].

Thirty-one patients with deep vein thrombosis (DVT) confirmed by phlebography 5-11 years previously were examined for the post-thrombotic syndrome (PTS). Where all of the patients were concerned, the examination included crossing-off of their symptoms of PTS on a special chart and clinical examination carried out by four doctors independently of one another, for 29 patients also determination of the venous return time by strain gauge pletysmography and for 29 patients also secondary phlebography (SF) and B-method ultrasonic scanning (UL). The degree of severity of PTS was determined by means of a scoring value which was calculated on the bases of four observers assessment of the clinical symptoms and findings. Significant differences were found for the clinical scores for legs with and without previous DVT, which shows that the method is of value despite a not inconsiderable interobserver variation. In the form employed here, pletysmography was found unsuitable for quantitating of PTS. In 60% of the patients, agreement was present between the clinical assessment, SF and UL. The necessity of agreement both as regards the diagnostic clinical criteria and as a measure for the degree of severity of PTS is emphasized. UL is recommended as a screening investigation for changes after DVT. Phlebography is only considered to be indicated in cases where detailed knowledge of the anatomical conditions is desired e.g. prior to venous surgery.

Adult↗
PubMed1991

[Standardized prothrombin time determinations and optimal anticoagulant therapy].

WHO and other international organizations have recommended the introduction of a standardized prothrombin time determination. This would allow a universal scale for the intensity of oral anticoagulation therapy to be used. A prerequisite is the use of thromboplastin, calibrated against the international reference thromboplastin, standardized methodology etc. This permits every prothrombin time determination to be expressed as International Normalized Ratio (INR). The introduction of INR facilitates the implementation of optimal oral anticoagulation as defined by larged international studies.

Anticoagulants↗
PubMed1991

Bias and random errors in historical data of exposure to organic solvents.

The biases and random errors in data from industrial hygiene measurements have been evaluated. Such data are often used for exposure assessment in epidemiologic studies by people who are not professional industrial hygienists. The quality of such data is, therefore, of paramount importance. Data sets from two investigations of the exposure to organic solvents in the same industry have been analyzed. The study shows that the errors and analysis of field samples are larger than errors determined from laboratory data but smaller than errors from other sources. One exception, in which laboratory errors are large, is when data originate from different ways of determining recovery. Very large biases may arise for certain combinations of analytes and extraction liquid when the "equilibrium method" is used. The data sets from the two investigations had a bias, which was as large as a factor of 5 to 10. This bias is believed to be caused by use of two different sampling strategies. In all industrial hygiene data, large random errors are embedded because of day-to-day variations in exposure levels; therefore, the data are mostly used grouped into three classes of low, medium, and high exposure. To do so is meaningful, as a large amount of data will compensate for misclassifications. But a large amount of data cannot compensate for the bias introduced when merging data generated under different sampling strategies. Data describing the same object, but originating from different sampling strategies, should not be pooled without proper tests, which show that data are comparable.(ABSTRACT TRUNCATED AT 250 WORDS)

Bias↗