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Biomedical subjects

J Olsen

Publications and source records attributed to J Olsen.

At least 289 records · Page 16Linked to original sources
PubMed1995

Is left-handedness a sensitive marker of prenatal exposures or indicators of fetal growth?

Left-handedness has been suggested as a sensitive marker of neurotoxic exposures or of the hormonal environment in fetal life. The prevalence of left-handedness was the subject of a follow-up study in children aged 5 to 9 years and correlated to exposures recorded by their mothers during pregnancy. Altogether 965 children were studied by means of questionnaires completed by the mothers. The response rate was 91%. Smoking, head circumference, Apgar score and indicators of fetal growth retardation were found not to be associated with increased prevalence of left-handedness.

Apgar Score↗
PubMed1994

[Low birth weight, stillbirth and congenital malformations. Social differences].

The aim of the study was to describe differences in life style variables according to socioeconomic groupings and to analyse the association between birth weight, stillbirth and congenital malformations according to the socioeconomic groupings for the father as well as the mother. It was conducted as a follow-up of 11,888 pregnant women in Odense and Aalborg, Denmark who were consecutively enrolled in the study from April 1984 to April 1987 as part of a community trial. Consecutively information regarding socioeconomic group and life-style factors were collected by means of self-administered questionnaires in the 36th week of gestation. Data on pregnancy outcomes were collected from birth certificates and medical records according to standardized search routines. It was found that women in the lower socioeconomic groups were younger, smaller, had a higher prepregnancy weight, smoked more and had a higher intake of coffee during pregnancy than women in higher socioeconomic groups. Better off women, on the other hand, had a higher consumption of alcohol, fish, and vegetables. Low birth weight was found to be negatively correlated to socioeconomic grouping. The lowest birth weights were found among babies born to unskilled and unemployed women even after adjustment for smoking habits, prepregnancy height and weight and a number of other potential confounders. Stillbirth and the prevalence of congenital malformations was not associated with socioeconomic grouping, but the amount of information was very limited regarding these outcomes. The study shows that socioeconomic status is especially a risk factor for low birth weight. This association is not only due to differences in life style factors of relevance for the outcome of pregnancy.

Alcohol Drinking↗
PubMed1994

1 kb of the lactase-phlorizin hydrolase promoter directs post-weaning decline and small intestinal-specific expression in transgenic mice.

Adult-type hypolactasia is a genetic condition making approximately one half of the human population intolerant to milk because of abdominal symptoms. The cause is a post-weaning down-regulation of the intestinal-specific enzyme lactase-phlorizin hydrolase (LPH) reducing the intestinal capacity to hydrolyze lactose. We here demonstrate that the stretch -17 to -994 in the pig LPH-promoter carries cis-elements which direct a small intestinal-specific expression and a post-weaning decline of a linked rabbit beta-globin gene. These data demonstrate that the post-weaning decline of LPH is mainly due to a transcriptional down-regulation.

Age Factors↗
PubMed1994

Two intestinal specific nuclear factors binding to the lactase-phlorizin hydrolase and sucrase-isomaltase promoters are functionally related oligomeric molecules.

Lactase-phlorizin hydrolase (LPH) and sucrase-isomaltase (SI) are enterocyte-specific gene products. The identification of regulatory cis-elements in the promoter of these two genes has enabled us to carry out comparative studies of the corresponding intestinal-specific nuclear factors (NF-LPH1 and SIF1-BP). Electrophoretic mobility shift assays demonstrated that the two nuclear factors compete for binding on the same cis-elements. The molecular size of the DNA binding polypeptide is estimated to be approximately 50 kDa for both factors. In the native form the factors are found as 250 kDa oligomeric complexes. Based on these results NF-LPH1 and SIF1-BP are suggested to be either identical or closely related molecules.

Base Sequence↗
PubMed1994

HNF1 alpha activates the aminopeptidase N promoter in intestinal (Caco-2) cells.

The importance of HNF1 binding proteins for intestinal aminopeptidase N expression was investigated using the Caco-2 cell-line. Aminopeptidase N promoter activity in Caco-2 cells depends on the HNF1 element (positions -85 to -58) and co-transfection with an HNF1 alpha expression vector demonstrates a direct activation of the promoter by HNF1 alpha through this element. Electrophoretic mobility shift assays using nuclear extracts from Caco-2 cells show the presence of high amounts of HNF1 binding proteins irrespective of their state of differentiation.

Aminopeptidases↗
PubMed1994

Utilization of side-chain precursors for penicillin biosynthesis in a high-producing strain of Penicillium chrysogenum.

Utilization of the side-chain precursors phenoxyacetic acid (POA) and phenylacetic acid (PA) for penicillin biosynthesis by Penicillium chrysogenum was studied in shake flasks. Precursor uptake and penicillin production were followed by HPLC analysis of precursors and products in the medium and in the cells. P. chrysogenum used both POA and PA as precursors, producing phenoxymethylpenicillin (penicillin V) and benzylpenicillin (penicillin G), respectively. If both precursors were present simultaneously, the formation of penicillin V was blocked and only penicillin G was produced. When PA was added at different times to cells that were induced initially for POA utilization and were producing penicillin V, the POA utilization and penicillin V formation were blocked, whereas the cells started utilizing PA and produced penicillin G. The blocking of the POA turnover lasted for as long as PA was present in the medium. If POA was added to cultures induced initially for PA utilization and producing penicillin G, this continued irrespective of the presence of POA. Utilization of POA increased concomitant with depletion of PA from the medium. Analysis of cellular pools from a growing cell system with POA as precursor to which PA was added after 48 h showed that the cellular concentration of POA was kept high without production of penicillin V and at a concentration comparable to the concentration in the medium. The cellular concentration of POA was higher than the concentration of PA that was utilized for penicillin G production.

Biotechnology↗
PubMed1994

Seizures after myelography with lopamidol.

A 32-year-old man presented to the emergency department (ED) with seizures 6 hours after a lumbar myelogram with iopamidol (Isovue-M 200, Squibb, Princeton, NJ). Seizures are a rare complication after myelography with the current nonionic contrast agents and have not been previously reported in the emergency medicine literature. Emergency physicians should be aware of this potential complication because outpatient myelograms are frequently performed, and these patients may present to the ED after seizures.

Adult↗
PubMed1994

Dietary risk factors for cancer and adenomas of the large intestine. A case-control study within a screening trial in Denmark.

The aims of the study were to estimate the importance of dietary habits for colorectal cancers and adenomas. By comparing risk factors among cancer and adenoma patients the adenoma cancer theory was indirectly evaluated. The study was performed as a case-control study within a large screening trial in Denmark. All cancer and adenoma patients diagnosed at the screening were recruited as cases; controls were selected among test negatives after matching for age, sex and time of screening. All those selected except 85, participated in a 7-day dietary recall. Altogether 49 colorectal cancer patients and 172 with adenomas were examined; 362 individuals who were test negatives in the Hemoccult-II screen served as controls. The intake of crude dietary fibres was shown to be associated with reduced risk of cancer as well as adenomas. Neither cancer nor adenoma occurrences were related to total energy intake or body mass. Vitamins E and A were negatively associated with adenoma occurrence.

Adenoma↗
PubMed1994

Effects of moderate alcohol consumption during pregnancy on child development at 18 and 42 months.

The aim of this study was to estimate the association between moderate alcohol consumption in pregnancy and child development to the age of 3.5 years. Furthermore, the aim was to compare development indices at 18 and 42 months of age. This study is an extension of the Danish participation in the EuroMac study. In a two-stage sampling, pregnant women in a well-defined region (Odense, Denmark) were recruited to a follow-up study according to their reported drinking habits in the first trimester of pregnancy. All among 2880 pregnant women who reported an alcohol consumption early in pregnancy (12th week of gestation) of at least 5 drinks/week were ascertained (164 women). A similar age and expected time of delivery matched group was selected from the remaining group of pregnant women. Alcohol consumption data were based on self-reported data, and child development recording was done blindly by two psychologists at 18 and 42 months after birth. Two hundred fifty-one mother-child pairs participated in all follow-up studies. None of the reported levels of alcohol intake was statistically significantly associated with any of the child development indices (including measures of binge drinking). Comparing child development indices at 18 and 42 months did, however, reveal a rather large variation over time for alcohol exposures, as well as nonexposures. A large variation in the outcome measure will tend to mask effects of any exposures, but nevertheless it is unlikely that a low alcohol intake in pregnancy has any substantial impact on child development.

Adult↗
PubMed1994

Acquired thermotolerance and heat shock proteins in thermophiles from the three phylogenetic domains.

Thermophilic organisms from each of the three phylogenetic domains (Bacteria, Archaea, and Eucarya) acquired thermotolerance after heat shock. Bacillus caldolyticus grown at 60 degrees C and heat shocked at 69 degrees C for 10 min showed thermotolerance at 74 degrees C, Sulfolobus shibatae grown at 70 degrees C and heat shocked at 88 degrees C for 60 min showed thermotolerance at 95 degrees C, and Thermomyces lanuginosus grown at 50 degrees C and heat shocked at 55 degrees C for 60 min showed thermotolerance at 58 degrees C. Determinations of protein synthesis during heat shock revealed differences in the dominant heat shock proteins for each species. For B. caldolyticus, a 70-kDa protein dominated while for S. shibatae, a 55-kDa protein dominated and for T. lanuginosus, 31- to 33-kDa proteins dominated. Reagents that disrupted normal protein synthesis during heat shock prevented the enhanced thermotolerance.

Adaptation, Physiological↗
PubMed1994

Options in making use of pregnancy history in planning and analysing studies of reproductive failure.

BACKGROUND: Although more epidemiological studies of reproductive health have been published recently, important scientific achievements remain few. Among the reasons for this are existing methodological constraints. Fertility is low in most parts of the industralized world, making the observation time short. Pregnancy itself is under extremely close medical surveillance with intensive health care interventions such as prenatal screening, induced abortions, induced labour, and prescribed changes in environmental exposures, but the epidemiologists are generally left with cause-effect experiences which escaped medical attention or study of diseases for which there is no cure. The main problem in non-experimental research of reproductive failure, however, is the most pregnancies are planned and past pregnancy experience is used in the planning. Self selection into different exposure categories according to past pregnancy experience should therefore be considered when studies are designed and analysed. STUDY OBJECTIVE: To consider how to deal with past pregnancy experience as an indicator "background" risk of reproductive failure. The present standard is to take parity or gravidity into consideration but this may be of little value and could even be very misleading. MAIN RESULTS: No simple and universal analytic strategy is available in reproductive epidemiology. On some occasions studies should be restricted to the first pregnancy only, in other situations the past reproductive experience may be used to form groups that are comparable in terms of pre-exposure risk.

Birth Order↗