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Biomedical subjects

E Hansen

Publications and source records attributed to E Hansen.

At least 73 records · Page 4Linked to original sources
PubMed1993

Visual impairment in Nordic children. V. X-linked juvenile retinoschisis.

In a study on 2,527 visually impaired children from four Nordic countries X-linked juvenile retinoschisis was diagnosed in 35 male children. Striking differences in frequency between the four countries were found, with 26 cases reported from Finland, 5 cases from Denmark, and 4 cases from Norway. None was reported from Iceland. The corresponding age and sex-specific prevalence rates of X-linked juvenile retinoschisis (N:1,000,000) were 44.5 in Finland, 8.8 in Denmark, and 7.9 in Norway. The uneven geographical distribution is possibly attributed to a 'founder effect' due to the settlements in Finland by European immigrants in the 17th century. The visual impairment of the registered cases was usually mild with 91.4% falling into WHO category 1. However, one child was totally blind, demonstrating large phenotypic heterogeneity. None of our cases had additional impairments. The majority were more than five years old, indicating a progressive course during childhood. Nevertheless, two children were diagnosed at the age of one. The most common age at registration was seven years, coinciding with the beginning of school attendance.

Adolescent↗
PubMed1993

Long-term treatment of macroprolactinomas with CV 205-502.

The long-term efficacy and tolerability of CV 205-502, a non-ergot dopamine agonist with D-2 receptor affinity, were studied for up to 36 months in 16 patients with macroprolactinomas. Prolactin values were reduced in all cases, becoming either normalized or suppressed in 12. The pituitary tumor size was reduced in the 13 patients with an obvious tumor and visual function normalized in all six patients with initial defects. Concomitantly we observed improvement in gonadal function, galactorrhea, headache, libido and general well-being. Adverse reactions were experienced by 15 patients during dosage increment and caused one patient to discontinue the medication. Seven patients had persistent adverse effects which prohibited a dosage increase of CV 205-502, sufficient to normalize PRL levels in three. Two patients experienced serious adverse events, causing the discontinuation of treatment in one case. In eight patients treatment with CV 205-502 and bromocriptine could be compared. Three patients responded better to CV 205-502 than to bromocriptine treatment. Only one patient preferred bromocriptine to CV 205-502 for long-term treatment. We conclude that CV 205-502 is an effective and in most cases well-tolerated treatment for patients with macroprolactinomas. CV 205-502 is preferable to bromocriptine as an initial treatment and should also be tried in patients where treatment with bromocriptine has failed.

Adult↗
PubMed1993

Genetic heterogeneity among blue-cone monochromats.

Thirty-three unrelated subjects with blue-cone monochromacy or closely related variants of blue-cone monochromacy were examined for rearrangements in the tandem array of genes encoding the red- and green-cone pigments. In 24 subjects, eight genotypes were found that would be predicted to eliminate the function of all of the genes within the array. As observed in an earlier study, the rearrangements involve either deletion of a locus control region adjacent to the gene array or loss of function via homologous recombination and point mutation. One inactivating mutation, Cys203-to-Arg, was found in 15 probands who carry single genes and in both visual pigment genes in one subject whose array has two genes. This mutation was also found in at least one of the visual pigment genes in 1 subject whose array has multiple genes and in 2 of 321 control subjects, suggesting that preexisting Cys203-to-Arg mutations constitute a reservoir of chromosomes that are predisposed to generate blue-cone-monochromat genotypes by unequal homologous recombination and/or gene conversion. Two other point mutations were identified: (a) Arg247-to-Ter in one subject with a single red-pigment gene and (b) Pro307-to-Leu in one subject with a single 5' red-3' green hybrid gene. The observed heterogeneity of genotypes points to the existence of multiple one- and two-step mutational pathways to blue-cone monochromacy.

Base Sequence↗
PubMed1992

[Overlooked posterior shoulder dislocation].

Posterior dislocation of the shoulder is frequently overlooked. Early diagnosis is a prerequisite for successful treatment. Supplementary axillary or apical oblique projections should be included in the routine radiograms to confirm the diagnosis.

Adult↗
PubMed1992

Transformation of a novel direct-repeat repressor element into a promoter and enhancer by multimerisation.

Studies on the regulation of interferon (IFN) responsive genes have mainly been centred on the highly conserved IFN stimulated responsive elements (ISREs) which can mediate type I and II IFN inducibility. To date little is known about other functional cis-acting regulatory motifs in IFN responsive genes. We report here on the identification of a repressor element in the human MxA gene defined to a 19 base pair (bp) region which houses a 9 bp direct repeat. DNA-specific protein binding on this element is not affected by IFN treatment and is distinct from ISRE binding proteins. Remarkably, contrary to expectations, when the repressor element is multimerised and spliced, in either orientation, to a reporter gene it behaves like a functional, constitutive promoter. Positioning the multimerised element in front of the SV40 enhancerless promoter also led to enhanced expression. The same protein(s) seem to bind to both the single repressor element and its multimerised form. This discovery of phenotypic reversal on a repressor element via multimerisation may have important implications in vivo.

Base Sequence↗
PubMed1992

Visual impairment in Nordic children. III. Diagnoses.

The diagnoses, according to type and site and the degree of visual impairment, responsible for severe visual impairment in children below the age of 18, were analyzed in a material compiled from the national registers of visually impaired in Denmark, Finland, Iceland and Norway. Among 2527 children the predominant causes of visual impairment are ascribed to congenital malformations, neuro-ophthalmological diseases and retinal diseases. Optic atrophy is the leading single cause of severe visual impairment when all diagnoses are compared, and this also applies when all categories of visual impairment are included. Retinopathy of prematurity is the second principal cause of severe visual impairment, while cerebral amblyopia rates as the third most significant cause. Congenital cataract is also of considerable importance when all categories of visual impairment are compared. The differences registered between the Nordic countries were found to be within reasonable limits, except for a preponderance of neuro-ophthalmological diseases in the Danish material. This could be explained by a better medical supervision of mentally retarded patients in Denmark. Additional impairments occur in a large percentage of patients, but are unevenly distributed in the disease groups. A high frequency of additional impairments are found in the neuro-ophthalmological group and in the groups with congenital malformations, emphasizing the importance of a multidisciplinary evaluation when dealing with the visually impaired child.

Adolescent↗
PubMed1992

Visual impairment in Nordic children. IV. Sex distribution.

A Nordic study group of ophthalmologists, NORDSYN, has compiled registers in Denmark, Finland, Iceland and Norway of 2527 visually impaired children aged 0-17 years. This paper is concerned with the sex-distribution in the registers and has documented a statistically significant excess of males in two of the registers (Denmark and Finland). The dominance of males seems to be related to two main conditions: 1. Genetic factors. 2. Perinatal factors. The genetic factors are mainly concerned with X-linked inheritance. The fact that perinatal influences involve visual impairment in males more than in females is difficult to account for. It may be conjectured, that the basis for perinatal visual damage is determined by unknown prenatal, possibly genetic, factors.

Adolescent↗
PubMed1992

Visual impairment in Nordic children. I. Nordic registers and prevalence data.

A Nordic study group of ophthalmologists, NORDSYN, has compiled data from registers in Denmark, Finland, Iceland and Norway of 2527 visually impaired children. Each record contains the following information: sex, year of birth, year of registration, classification of visual impairment, ocular diagnosis, systemic diagnosis, aetiology and evt. additional impairments. The ocular diagnoses were compiled into groups, and coding systems for aetiology and additional impairment were developed. The sex distribution revealed a dominance of males compared to the general population at the same age. Cases with non-genetic aetiology showed--through to a lesser extent--the same relative preponderance of males. The diseases in males caused by x-linked genetic factors do, therefore, not fully explain the sex distribution observed in the study. The national prevalences for registration of childhood blindness (WHO-definition: best corrected visual acuity in the best eye less than 3/60 or visual field less than 10 degrees around fixation for the ages 0-15 years) are per 100,000 child-population aged 0-15 years: Denmark 41, Finland 15, Iceland 19 and Norway 15. The differences are primarily presumed to be due to varying efficiency in registration. The proportion of visually impaired children with an additional mobility, hearing or mental impairment is between one-third and one-half of the national materials, thus indicating the need for interdisciplinary tracing of and care for the visually impaired child. This study documents the need of uniform routines for data classification of visually impaired children. The quality of the data in the present study calls for caution in the interpretation of the prevalence estimates. Incidence studies are being prepared to obtain information on whether the amount and causes of visual impairment in children with or without multiple impairments are changing.

Adolescent↗
PubMed1992

Visual impairment in Nordic children. II. Aetiological factors.

Careful clinical-aetiological assessment of visually impaired children is one of the prerequisites for prevention of future, 'unavoidable' cases of visual impairment of children in the industrialized part of the world. In a collaborative study (NORDSYN) between four Nordic national registers of visual impairment, we analysed and classified some of the factors considered to be essential components for the development of low vision or blindness in children. We discuss the conceptual basis for aetiological classification of eye disorders and visual impairment. An aetiological classification system, based on the type and debut of an essential causal factor is introduced. We present data on 2527 visually impaired children from the Nordic countries. In accordance with several other reports from the last twenty years it is demonstrated that prenatal factors, including genetic aetiologies, were involved in a large proportion (66%) of the cases. In children without additional impairments the corresponding fraction was 74%. Genetic factors accounted for a little over half of the prenatal cases, and in a substantial number of children (40%) with visual impairments of prenatal origin, the causes were obscure. In 1/5 of the material some peri-neonatal causal or modifying factor was identified. In 7% only, the presumed aetiological factor was introduced in the infantile-juvenile period of life. Further prevention of visual impairment among children of the industrialized countries would benefit most from a more comprehensive understanding of prenatal, nongenetic causal factors, further knowledge about regulating mechanisms responsible for gene expression, and additional improvements in perinatal care.

Adolescent↗
PubMed1992

A double blind study of single dose azithromycin and doxycycline in the treatment of chlamydial urethritis in males.

OBJECTIVE: To compare the efficacy and safety of azithromycin and doxycycline in the treatment of males with uncomplicated urethritis caused by chlamydia trachomatis. DESIGN: A multicentre, double-blind, randomised treatment study. SUBJECTS: 130 male outpatients with clinical signs and symptoms of urethritis. SETTING: STD clinics at four Norwegian University Hospitals. METHODS: Patients were randomly allocated to 1000 mg azithromycin as single dose or doxycycline 100 mg twice daily for 7 days. Clinical, bacteriological and safety assessments were made at entry and after 1 and 2 weeks. Safety data were also repeated after 4 weeks. RESULTS: Demographic data were similar in both groups. At the week 1 assessment bacteriological eradication was achieved in 44 of 44 evaluable azithromycintreated patients and in 42 of 42 in the doxycycline group. At the week 2 assessment the corresponding figures were 35 of 35 and 34 of 34 respectively. CONCLUSION: Azithromycin 1000 mg single dose was as effective as doxycycline 100 mg twice daily for 7 days in male patients with chlamydial urethritis.

Adolescent↗
PubMed1992

Switches in fish myosin genes induced by environment temperature in muscle of the carp.

Fish are cold blooded animals and their muscle function is expected to be greatly affected by environmental temperature. Species that live in the Antarctic ocean have evolved a different contractile system to fish that live in the tropical waters. In the case of Antarctic fish they have a higher specific myofibrillar ATPase activity but 'the trade off' seems to be a lower thermal stability. They are thus capable of a greater muscle power output at low temperatures but the lower thermal stability means they are restricted to living at temperatures below +4 degrees C. Some species, however, experience a wide range of seasonal variations in temperature. We found that these species adapt by changing their myofibrillar apparatus so that they have a higher specific ATPase which physiological studies indicate is due to a different type of myosin crossbridge for low temperature swimming. This is reversible and they develop a contractile system with a greater thermal stability and a commensurate loss of ATPase activity when their environment warms up again. There were several possibilities by which this may be achieved including expression of different isoform genes or the post- translational processing of existing proteins. To elucidate the mechanism we made a carp genomic library and screened this for myosin heavy chain gene using mammalian cDNA sequences under moderate stringency conditions. The clones were restriction mapped which resulted in 28 non overlapping sequences. This indicated that the carp had a reasonably large family of myosin heavy chain genes that is about twice the size of that in mammals. Rather fortuitously the first sequence to be identified was from the gene that is predominantly expressed in white muscle at warm temperatures. This was done by extracting the RNA from red and white muscle of fish acclimated to different 25 degrees C, 18 degrees C or 8 degrees C and carrying out Northern analysis using the gene fragment as the probe. The time course for the expression of this gene when carp maintained at a low temperature were acclimated to a warm temperature was slightly in advance of the change in myofibrillar ATPase which suggested that this strategy for adaptation is regulated at the transcriptional level. Hence these species of fish can adapt to seasonal changes in temperature by expressing different myosin heavy chain isoform genes and rebuilding their myofibrils for either warm or cold temperature swimming. At the present time we are characterising the 5' regulatory (promoter) sequence of this gene to see how a temperature switch may operate.(ABSTRACT TRUNCATED AT 400 WORDS)

Adaptation, Physiological↗
PubMed1991

Strong expression of foreign genes following direct injection into fish muscle.

We report here for the first time direct injection of genes into fish muscle in vivo. Plasmids used contain either SV40 early promoter, rabbit beta-cardiac myosin heavy chain promoter, human MxA promoter or an artificial promoter, fused to a chloramphenicol acetyltransferase (CAT) or beta-galactosidase reporter gene. CAT assays revealed that most gene constructs were highly expressed. Histochemical analysis showed that beta-galactosidase was strongly expressed at the site of injection within muscle fibres. This method provides an excellent system for testing expression of gene constructs, including those of mammalian origin, in fish muscle in vivo and has the potential for fish vaccination.

Age Factors↗
PubMed1991

Molecular and functional analysis of the virus- and interferon-inducible human MxA promoter.

The virus- and interferon-inducible human MxA (IFI-78k) gene is a homologue of the murine influenza resistance gene Mx1. Three overlapping human cosmid clones covering most of the gene including its promoter region were isolated. Sequencing the 5' MxA cDNA derived by RT-PCR (reverse transcriptase-polymerase chain reaction) confirmed the most 5' putative transcriptional start site. The MxA promoter does not contain a TATA or CCAAT box but has three Interferon Stimulated Response Element (ISRE) motifs. Strong induction with type I interferons was demonstrated with a fragment containing only two ISREs in human L132 cells. This induced expression was not adversely affected by 2-aminopurine. However, the promoter showed constitutive expression in transiently or stably transfected murine LM cells.

Animals↗
PubMed1991

Motor imagination--a model for motor performances?

The effect of training competition (TC) on central nervous activation was investigated in order to examine whether motor imagination could serve as a model for complex motor skills concerning information processing and motor control. EEG was recorded before and immediately after the TC. The mean alpha frequency (MAF) was computed from the EEG power density spectra. A significant increase of MAF was found after the TC. Similar changes were found during motor imagination. Thus, motor imagination seems to be a good model to examine activation processes.

Electroencephalography↗
PubMed1990

Embryotoxicity and teratogenicity study in rats dosed epicutaneously with dimethylformamide (DMF).

The reproductive effect of N,N-dimethylformamide (DMF) administered epicutaneously to rats was examined. The rats were dosed on gestation days 6-15 or on gestation days 1-20 at dose levels of up to 2 ml DMF kg-1 body weight. Body weight, weight gain and pregnancy rate were reduced in those rats receiving 2 ml DMF kg-1 body weight per day on days 6-15. A reduction in the number of live fetuses and in fetal weight, as well as an increase in postimplantation loss, were also observed at this dose level. Similar but more pronounced effects were observed in rats dosed on days 1-20 with 2 ml DMF kg-1 body weight. The lowest effect level was 1 ml DMF kg-1 body weight. No other dose-related effects were found in this study.

Administration, Topical↗
PubMed1990

Dynamics of central nervous activation during motor imagination.

Central nervous processes of sensorimotor and behaviour control are prerequisites of skills and motor performance. Eight students (Ss) in sports were tested during motor imagination. They were requested to imagine their own movements when swimming over a distance of 100 m (sitting in a resting position, without any real or imitated movements). Electroencephalograms (EEG), heart rate (HR), skin conductance (SC), and respiration rate (RR) were recorded before, during and after one series of 3 periods of mental training (MT). HR, RR and SC increased during MT. The highest level of SC can be found at the beginning of the first period of imagination. Mean alpha-frequency of the EEG over the left occipital and precentral area in all Ss was higher during MT. The degree of these changes varied during the 3 imagination periods.

Brain↗