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Biomedical subjects

L Larsen

Publications and source records attributed to L Larsen.

At least 19 recordsLinked to original sources
PubMed1991

Direct derivation of conditionally immortal cell lines from an H-2Kb-tsA58 transgenic mouse.

Studies on cell lines have greatly improved our understanding of many important biological questions. Generation of cell lines is facilitated by the introduction of immortalizing oncogenes into cell types of interest. One gene known to immortalize many different cell types in vitro encodes the simian virus 40 (SV40) large tumor (T) antigen (TAg). To circumvent the need for gene insertion in vitro to generate cell lines, we created transgenic mice harboring the SV40 TAg gene. Since previous studies have shown that TAg expression in transgenic mice is associated with tumorigenesis and aberrant development, we utilized a thermolabile TAg [from a SV40 strain, tsA58, temperature sensitive (ts) for transformation] to reduce the levels of functional TAg present in vivo. To direct expression to a broad range of tissues, we used the mouse major histocompatibility complex H-2Kb promoter, which is both widely active and can be further induced by interferons. tsA58 TAg mRNA was expressed in tissues of all animals harboring the hybrid construct. Development of all tissues was macroscopically normal except for thymus, which consistently showed hyperplasia. Fibroblast and cytokeratin+ thymic epithelial cultures from these mice were readily established without undergoing crisis and were conditionally immortal in their growth; the degree of conditionality was correlated with the levels of tsA58 TAg detected. One strain of H-2Kb-tsA58 mice has been bred through several generations to homozygosity and transmits a functional copy of the transgene.

Animals↗
PubMed1990

Salmonella and Shigella carriers among refugees from the middle east and Sri Lanka in Denmark.

One per cent of ten thousand refugees were asymptomatic carriers of Salmonella and Shigella species found by a differentiated health check programme at a Danish Red Cross arrival centre in Denmark 1985 and 1986. Six patients with typhoid fever and one with S. parathyphi-A septicaemia all fell ill within the first few weeks after arrival. A child of a chronic S. typhi carrier developed typhoid fever four months after arrival. Cases of sporadic and mild diarrhoea occurred due to Salmonella and Shigella species. The carriers were instructed in prophylactic, hygienic measures and no outbreaks developed. The health check system in this period seemed to be sufficient in relation to preventing outbreaks of infections caused by non-typhoid Salmonella and Shigella species. The relative cost-effectiveness of a more intensive S. typhi screening on arrival is questionable. The organization of health check systems should be reviewed regularly, as each refugee situation is different and will change in different periods.

Carrier State↗
PubMed1989

[Local reactions following intravenous injection of Valium mixed micelles and Diazemuls].

The frequency of local venous reactions after intravenous injection of Diazemuls and Valium Mixed Micelles was studied. A material of 224 patients undergoing surgery for prolapsed lumbar disc was allocated into two groups, receiving either 10 mg of Diazemuls or Valium Mixed Micelles. The incidences of thrombophlebitis in the two groups were 1 and 2%, respectively.

Adult↗
PubMed1979

Epidemic of chancroid in Greenland 1977-78.

In Greenland there has been a rapid increase in the incidence of gonorrhoea and syphilis during past decades. In 1977 there was an epidemic of chancroid along the west coast of Greenland, with 975 cases reported from some 32,500 adults. The number of reported cases increased until October, 1977, and subsequently decreased. 186 patients were studied. Many of these had previously had gonorrhoea and syphilis. Male patients were both Eskimoan and Danish but female patients were solely Eskimoan. The sex ratio (M/F) was 1.6/1. The incubation period was 4 days in men and 13 days in women. Symptom-free female carriers did not seem to be an important reservoir of infection. 15% of the patients were admitted to hospital with buboes or extensive lesions. The clinical course was uncomplicated in most cases. Ulcers healed within a week of treatment with sulphonamide. Chancroid can be expected to disappear in Greenland within a short time.

Adolescent↗
PubMed1979

Iron absorption and iron status in patients with chronic uremia on regular peritoneal dialysis.

Gastrointestinal iron absorption was measured by whole body counting in 18 patients on regular peritoneal dialysis. Ten patients received regular oral iron treatment prior to the study (iron treated group), 8 patients did not receive iron treatment (non-iron treated group). Whole body retention 14 days after oral administration of 10 microCi 59Fe together with a carrier dose of 10 mg Fe2+ was used as an estimate of absorption. The erythrocyte iron incorporation, i.e. the percentage of administered 59Fe incorporated into the total erythrocyte mass, was measured. Geometric mean iron absorption in the non-iron treated groups was 7.4+/-3.3 (S.D.) % and in the iron treated group 2.8+/-2.5% (p less than 0.01). Absorption in the non-iron treated group did not differ significantly from the value in a normal control group (p greater than 0.3). Absorption in the iron treated group was distinctly lower than in the controls (p less than 0.01), due to the high iron supplementation. Several patients in the non-iron treated group had latent or overt iron deficiency, while patients in the iron treated group had satisfactory iron status. The correlation between iron absorption and erythrocyte iron incorporation was highly significant (r=0.95, p less than 0.001). Peritoneal dialysis patients on the whole have a normally functioning iron absorption. However, due to increased iron losses and insufficient dietary iron intake, the maintenance of a satisfactory iron balance implies an adequate oral iron supplementation.

Absorption↗
PubMed1979

Menstrual characteristics of 2,343 women attending the Shepherd Foundation.

Menstrual characteristics of 2,343 women attending the Shepherd Foundation Health Testing Centre have been analyzed utilizing a computer system of data analysis. The incidence of menstrual pain was 43% and premenstrual tension 75%. The best estimate of normal cycle length was 21-35 days, 1.5% of women having cycles less than 21 days. The duration of menstrual loss was 1-7 days, 3% of women bleeding for more than 7 days. Utilizing the various responses to questions concerning menstrual and cycle length, menstrual pain and premenstrual tension, 150 patterns were found, the 10 most common patterns accounting for 40% of the population; most of the latter patterns included menstrual pain and premenstrual tension. Authorities disagree upon the definitions of normal menstruation and there are serious implications from the lack of knowledge in this area, both for the individual patient and the cost of health care. The formation of a health committee to determine national standards for defining normal menstruation is advocated.

Adolescent↗
PubMed1979

Social and psychological factors in relation to premenstrual tension and menstrual pain.

Age, country of birth, marital status, attitude to work, smoking and drinking habits, childbearing, sex life and psychological factors are all linked to the frequency of menstrual pain and premenstrual tension. The relationship between the psychosocial and menstrual characteristics may be causal or related to some other constitutional factor (or factors) which determines both. The profile of women suffering from premenstrual tension and menstrual pain is described. In management, associated psychosocial factors and the relationship betweem these and the described menstrual problems needs to be taken into account.

Adolescent↗
PubMed1979

Duration of menstruation.

Menstrual length was analysed in 2,342 women attending the Shepherd Foundation. Prolonged menses were more common in Australian and New Zealand born, in women with irregular, short or long menstrual cycles, menstrual pain, high parity, and an intrauterine device. In contrast to women with premenstrual tension and menstrual pain, psychological factors, smoking and drinking were not more common in women with increased menstrual length. It is concluded that somatic factors alone control menstrual length, and results in the present study support the hypotheses that both the hypothalamic-pituitary system and prostaglandins may be involved in this control. Evidence was found that the use of the contraceptive pill reduces the incidence of premenstrual tension when menstrual length is also reduced.

Contraception↗
PubMed1979

Folate deficiency in chronic inflammatory bowel diseases.

In a consecutive study of 216 outpatients with chronic inflammatory bowel diseases (CIBD) low serum and erythrocyte folate levels were found in 59% and 26%, respectively. In patients with low folate levels in both serum and erythrocytes, megaloblastic changes in the bone marrow ere found in 67% (29 out of 44). Their folate intakes were borderline. Absorption studies with tritiated folate showed low absorption values on repeated examinations in 23% of the patients with low folate values (9 out of 40), with no relationship to the intake of salazosulphapyridine. In patients with low folate values the reticulocyte count was elevated (related to the dose of salazosulphapyridine), and the 51Cr erythrocyte survival was decreased. It is suggested that folate deficiency in CIBD is of multiple origin: inadequate diet, malabsorption, and chronic drug-induced low-grade haemolysis. The clinical consequence of the findings remains to be evaluated.

Bone Marrow↗