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Biomedical subjects

M Olofsson

Publications and source records attributed to M Olofsson.

15 recordsLinked to original sources
PubMed2003

Induction of early light-inducible protein gene expression in Pisum sativum after exposure to low levels of UV-B irradiation and other environmental stresses.

Plants are constantly subjected to environmental changes and have developed various defence mechanisms to facilitate their continued existence. Pisum sativum plants were exposed to low levels of UV-B radiation and ELIP (early light-inducible proteins) mRNA, with a probable protective function, was rapidly and strongly induced during this type of stress. To our knowledge, this is the only photosynthetic gene that is up-regulated following exposure to UV-B, and this result has to be compared with studies predominantly reporting down-regulation by UV-B of genes encoding proteins localised in the plastid. The expression pattern of ELIP mRNA in pea was also investigated during salt, wounding and ozone stress. The transcript levels of ELIP were induced after the salt and wounding treatments but not during ozone fumigation.

Arabidopsis Proteins↗
PubMed1999

Biokinetics and radiation doses for carbon-14 urea in adults and children undergoing the Helicobacter pylori breath test.

The long-term biokinetics and dosimetry of carbon-14 were studied in nine adults and eight children undergoing carbon-14 urea breath test for Helicobacter pylori (HP) infection. The elimination of 14C via exhaled air and urine was measured with the liquid scintillation counting technique and with accelerator mass spectrometry. After the subjects had been given 110 kBq 14C-urea (children: 55 kBq) orally, samples of exhaled air were taken up to 180 days after administration and samples of urine were collected up to 40 days. Sixteen of the subjects were found to be HP-negative. In these subjects a total of 91.1%+/-3.9% (mean of adults and children +/- standard error of the mean) of the administered 14C activity was recovered. The majority of the administered activity, 88.3%+/-6.2% in adults and 87.7%+/-5.0% in children, was excreted via the urine within 72 h after administration. A smaller fraction was exhaled. In adults 4.6%+/-0.6% of the activity was exhaled within 20 days and in children 2.6%+/-0.3%. Uncertainties in the biokinetic results are mainly due to assumptions concerning endogenous CO2 production and urinary excretion rate and are estimated to be less than 30%. The absorbed dose to various organs and the effective dose were calculated using the ICRP model for urea and CO2. The urinary bladder received the highest absorbed dose: in adults, 0.15+/-0.01 mGy/MBq and in children of various ages (7-14 years), 0.14-0.36 mGy/MBq. The findings indicate that an investigation with 14C-urea gives an effective dose to adults of 2.1+/-0.1 microSv (for 110 kBq) and to children of 0.9-2.5 microSv (for 55 kBq). From a radiation protection point of view, there is thus no reason for restrictions on even repeated screening investigations with 14C-urea in whole families, including children.

Adolescent↗
PubMed1996

Influences of intentionality at encoding and retrieval on memory in adulthood and old age.

This research investigated whether different memory functions are differentially affected by the adult aging process. Four groups of normal adults (18-35, 60-68, 69-78, and 79-91 years of age) were presented with a set of pictures of faces with first names and surnames. Subjects were instructed to memorize the faces and the surnames for subsequent memory tests. Memory performance was assessed in four ways: stem completion of surnames; recognition of faces; recognition of surnames and recognition of first names. These memory tests varied in terms of intentionality at encoding and retrieval. The stem completion task involved intention at encoding, but not at retrieval, and thus served as a measure of implicit memory. With respect to the three explicit memory tasks, recognition of faces and surnames involved intention at both encoding and retrieval, whereas recognition of first names involved intention at retrieval, but not at encoding. Results indicated no age-related differences in implicit memory, as assessed by the stem completion test. In addition, there was an age-related deficit in recognition of faces and surnames, although there were no age-related differences in recognition of first names. The overall pattern of results suggests that age-related deficits in memory may be most likely to occur when there are demands of conscious mental activity at encoding and retrieval.

Adolescent↗
PubMed1995

Differences in binding of platelet factor 4 to vascular endothelium in vivo and endothelial cells in vitro.

The binding of fluorescein-labelled recombinant human platelet factor 4 (rhPF4) to the vasculature of the hamster cheek pouch in vivo was compared with that to cultured endothelial cells (EC) from human umbilical veins (HUVEC) and arteries (HUAEC) and from human aorta (HAEC). In vivo data: systemically injected rhPF4 rapidly disappeared from plasma in a biphasic pattern (t1/2 = 2 and 41 min). High intensity non-uniform binding of rhPF4 occurred at short specific sites along both arterioles and venules. The length of the intense sites was 76 +/- 46 microns and their frequency was 10 +/- 4 per cm2 cheek pouch. Heparin was injected at 4 and 9 min, but not 30 min, post-rhPF4 displaced most of the high intensity labelling indicating internalization with time. Neither pretreatment with more than 50-fold excess of unlabelled rhPF4 nor histamine- or LTB4-induced vascular macromolecular leakage changed the frequency of short intense sites. In vitro data: uniform time-dependent intense binding of rhPF4 occurred in a similar fashion in subconfluent HUVEC, HUAEC and HAEC. All cell types showed nuclear staining, demonstrating internalization. When heparin was given to EC prior to rhPF4, binding was delayed in time but not blocked. In conclusion, rhPF4 does not bind uniformly with high intensity along pre- and post-capillary vessels of the hamster cheek pouch in vivo as predicted by the rhPF4-labelling of subconfluent (migrating/proliferating) human EC in vitro. The short infrequent sites of intense rhPF4-labeling in vivo may represent regions of endothelial cell migration/proliferation similar to subconfluent EC in culture.

Animals↗
PubMed1989

[Children and AIDS].

Children suffering from HIV-infection is a serious and increasing problem all over the world. The pediatric AIDS cases are usually transmitted through vertical transmission from a HIV-infected mother to the fetus during pregnancy, but it is not possible before the age of 15 months to decide with certainty whether the infant is infected or not. The risk of HIV-transmission from mother to fetus is about 50 per cent. The prognosis of the infected infants are very bad, the morbidity and mortality are high. In USA 60 per cent of the infants with congenit HIV-infection have died before the age of 2 years. The progress of HIV-infection in infants and children is characterized by bacterial infections with subsequent sepsis, neurological symptoms and regression of the psychomotor development. Most of the families are basically suffering from severe psychosocial problems eg drug abuse and at least one of the parents is HIV-infected. A family with a HIV-antibodypositive child is a family suffering from crises, illness, lack of resources and social isolation, and is therefore in need of medical, psychological and social treatment and support. It is urgent to help these children and their families through interdisciplinary intervention to give the children an optimal quality of life. To obtain this it is necessary with interdisciplinary comprehensive programs and multidisciplinary collaboration in the community. And in these programs it is important to prioritate the primary prophylaxis in trying to reduce the number of infants born in risk of HIV-infection.

Acquired Immunodeficiency Syndrome↗
PubMed1983

Investigation of 89 children born by drug-dependent mothers. I. Neonatal course.

Among 89 infants born by opiate- and methadone-addicted mothers 20% were preterm and 31% were light for gestational age. Mean gestational age and birth weight were lower in infants of mothers who had taken mainly opiates compared with infants of mothers who had taken mainly methadone. Preterm labor was more frequent among women who had been acutely withdrawn on methadone within the last month before birth than among women who were maintained on methadone at birth. 85% of the newborns had withdrawal symptoms and 12% had convulsions the severity of which was not correlated with the type of drug abuse. The duration of withdrawal, however, correlated with the amount of methadone taken by the mother at birth. 20% had signs of perinatal asphyxia and had an increased frequency of neonatal convulsions. These babies represent a special high-risk group of newborns. Prevention, therapy and care demand extraordinary combined efforts by politicians, social welfare personnel, midwives, doctors and nurses.

Adult↗
PubMed1983

Investigation of 89 children born by drug-dependent mothers. II. Follow-up 1-10 years after birth.

72 of 89 children born by opiate- and methadone-addicted mothers were reinvestigated 1 to 10 years after birth. Only 25% were found to by physically, mentally and behaviorally normal. 56% were hyperactive, aggressive, with a lack of concentration and social inhibition. 10% had a severely and 11% a moderately impaired psycho-motor development mainly due to deprivation. 43% of the children had been removed from their mothers by the courts. The average number of shifts from one milieu to another was 6 per child with an upper range of 30 shifts for some of the children. The average number of shifts from one caregiver to another was 5 with an upper range of 11. These findings indicate that there is an urgent need for politicians, social welfare and health personnel to reexamine their roles in helping these children, who will otherwise develop into a new generation of social loosers.

Adult↗
PubMedDate not supplied

Predictors of prose recall in adulthood and old age.

One group of young adults and three groups of older adults (young-old, old, old-old) were examined in immediate recall of random and organizable words, and immediate and delayed recall of prose passages. Results showed that all groups of older adults recalled less from the prose passages and the word recall tasks than the younger adults, although there were no performance differences among the three older samples. As well, all age groups showed a similar increase in recall of organizable words compared with random words, and all age groups showed parallel forgetting curves in prose recall. These results suggest that all age groups utilized the organizational support to the same extent, and that forgetting rate was not influenced by age. Regression analyses showed that recall of random and organizable words, education, vocabulary and age all contributed to prose recall performance. Most important, the importance of markers of strategy use (word recall tasks) for prose recall decreased from early to late adulthood, whereas the importance of a semantic memory marker (vocabulary) showed the opposite pattern.

Journal Article↗
PubMedDate not supplied

Growth and clonogenic assays compared for irradiated MCF-7 and Colo-205 cell lines.

Clonogenic assays have been the golden standard for the assessment of cytotoxic injury from irradiation or drugs. Since such assays are time consuming, growth assays, often with automatic quantifying equipment, are frequently used. Since these procedures do not immediately reflect loss of clonogenic capacity, it was considered important to validate the two procedures using gamma-irradiation (0, 2 and 4 Gy) of two human cell lines (MCF-7 and Colo-205). The cells were growing exponentially in 96-well plates and crystal violet staining resulted in optical densities proportional to cell number. The homogeneity of optical densities within the plates was optimal if the wells to be measured were surrounded by liquid-containing ones. The slopes of the exponential growth curves were decreased upon irradiation. An "apparent cell survival", the mean of the three lowest ratios between irradiated and control cells, was defined. It was compared with the SF2 and SF4 as found in parallel Courtenay-Mills assays. In this work we found a modest underestimation of cell survival using the growth assay, ranging from 0 to 17 per cent in absolute terms.

Cell Division↗