Search PubMed⌕ Search

Biomedical subjects

A Olsen

Publications and source records attributed to A Olsen.

At least 19 recordsLinked to original sources
PubMed1992

Assembly and analysis of cosmid contigs in the CEA-gene family region of human chromosome 19.

The carcinoembryonic antigen (CEA)-like genes are members of a large gene family which is part of the immunoglobulin superfamily. The CEA family is divided into two major subgroups, the CEA-subgroup and the pregnancy-specific glycoprotein (PSG)-subgroup. In the course of an effort to develop a set of overlapping cosmids spanning human chromosome 19, we identified 245 cosmids in a human chromosome 19 cosmid library (6-7X redundant) by hybridization with an IgC-like domain fragment of the CEA gene. A fluorescence-based restriction enzyme digest fingerprinting strategy was used to assemble 212 probe-positive cosmids, along with 115 additional cosmids from a collection of approximately 8,000 randomly selected cosmids, into five contigs. Two of the contigs contain CEA-subgroup genes while the remaining three contigs contain PSG-subgroup genes. These five contigs range in size from 100 kb to over 300 kb and span an estimated 1 Mb. The CEA-like gene family was determined by fluorescence in situ hybridization to map in the q13.1-q13.2 region of human chromosome 19. Analysis of the two CEA-subgroup contigs provided verification of the contig assembly strategy and insight into the organization of 9 CEA-subgroup genes.

Carcinoembryonic Antigen↗
PubMed1991

Physiological parameters in ecotoxicology.

1. Regulated physiological parameters are normally maintained at a constant level by regulatory mechanisms. Acute toxic effects develop whenever a pollutant causes a regulated parameter to be displaced beyond tolerated limits, and thus, regulated parameters may be convenient toxicity parameters. The present study indicates that delta mu Na+ across the adductor muscle membrane of Mytilus edulis is a regulated parameter, and that injuries develop whenever this parameter drops below -700 J/mole. 2. Regulatory physiological parameters may display quick and substantial changes when regulatory mechanisms are activated to counteract variations in the regulated parameters. Thus, regulatory parameters may be used as sensitive alarm parameters in environmental monitoring. The present results indicate that the phosphate index [(ATP x P-arginine)/(Pi)2], metabolic rate and strombine may be used as alarm parameters. 3. The combined response of all parameters may provide a pollutant-specific fingerprint in environmental monitoring.

Animals↗
PubMed1991

Measurements of oxygen consumption in Mytilus edulis during exposure to, and recovery from, high sublethal concentrations of formaldehyde, benzene and phenol.

1. The rate of oxygen consumption has been monitored continuously in M. edulis during acute exposure to high sublethal concentrations of formaldehyde, phenol and benzene and subsequent recovery periods of 96 hr. 2. The results are discussed in relation to changes in the electrochemical potential difference of sodium, the content of ATP and the tissue concentration of strombine. 3. After exposure to benzene and phenol, an increase in the rate of oxygen consumption that could not be explained by oxygen debt from the exposure period was observed. 4. Depression of the rate of oxygen consumption after exposure to formaldehyde may be explained by a reduced ability to extract oxygen from the water. 5. The pattern of oxygen consumption and behavioural responses, as well as the combined changes in the biochemical markers, were distinctly different in the three cases.

Animals↗
PubMed1990

Interferon-gamma reverses the stimulation of collagen but not fibronectin gene expression by transforming growth factor-beta in normal human fibroblasts.

It has recently become apparent that several cytokines and growth factors are capable of modulating fibroblast proliferation and biosynthetic activity. To understand the role of these factors in connective tissue regulation, we examined the effects of the simultaneous addition of interferon-gamma (IFN-gamma) and transforming growth factor-beta (TGF-beta) on normal human dermal fibroblast collagen and fibronectin production. In addition, in vitro transcription rates and steady-state mRNA levels for these molecules were determined by nuclear run-off assays and Northern and dot-blot hybridization using specific human cDNA probes. Treatment of cultures with TGF-beta caused stimulation of collagen and fibronectin production. Addition of IFN-gamma to the TGF-beta-treated cultures abrogated the stimulatory effects of TGF-beta on collagen production in a dose-dependent manner and resulted in a net inhibition of collagen production. In contrast, the increase in fibronectin synthesis induced by TGF-beta was augmented further by IFN-gamma. These changes in collagen and fibronectin production were accompanied by parallel changes in the steady-state mRNA levels for these proteins. The effects of TGF-beta plus IFN-gamma on fibronectin gene expression appeared to be mediated entirely by transcriptional mechanisms, whereas the effects on collagen gene expression resulted from a combination of transcriptional and post-transcriptional events.

Cells, Cultured↗
PubMed1990

The natural history of functional morbidity in hospitalized older patients.

This study provides data on changes in the functional status of older patients that are associated with acute hospitalization. Seventy-one patients over the age of 74 admitted to the medical service of Stanford University Hospital between February and May 1987 received functional assessments covering seven domains: mobility, transfer, toileting, incontinence, feeding, grooming, and mental status. Assessments were obtained by report from the patient's caregiver (or the patient when he or she lived alone) for 2 weeks before admission; from the patient's nurse on day 2 of hospitalization and on the day before discharge; and again from the caregiver (or patient) 1 week after discharge. The sample had a mean age of 84, covered 37 Diagnostic Related Groups, and had a median length of stay of 8 days. Between baseline and day 2, statistically significant deteriorations occurred for the overall functional score and for the individual scores for mobility, transfer, toileting, feeding, and grooming. None of these scores improved significantly by discharge. In the case of mobility, 65% of the patients experienced a decline in score between baseline and day 2. Between day 2 and discharge, 67% showed no improvement, and another 10% deteriorated further. These data suggest that older patients may experience a burden of new and worsened functional impairment during hospitalization that improves at a much slower rate than the acute illness. An awareness of delayed functional recovery should influence discharge planning for older patients. Greater efforts to prevent functional decline in the hospitalized older patient may be warranted.

Activities of Daily Living↗
PubMed1990

Infertility, technology and the law. Patients' and future doctors' opinions.

The rectifying of infertility by application of modern technology has been a topic for debate in modern society over the past decade. Laws regulating the investigation and treatment of infertility have been passed in many countries, for instance in Norway and Sweden, while other nations await future developments. In this paper, some users of the technology--female infertility patients and future medical doctors--present their attitudes toward controversial issues of infertility, investigated by means of a survey questionnaire issued to them in 1987-88. Medical students have a more restrictive attitude than former patients, whereas religious beliefs influence the viewpoints of the patients. Both groups seem to have opinions that to a large degree accept the content of the Norwegian law.

Adult↗
PubMed1989

Progress toward structure determination.

Convergent-beam electron diffraction provides more precise measurements of diffracted intensity than the traditional method of selected-area diffraction. The intensity is recorded at well-defined beam directions for each reflection in the pattern within disks defined by the incident cone of rays. Measurements relating to structure factors or parameters can be arranged in different ways: intensities at the zone axis position; Kossel line profiles or integrated intensities across Kossel lines; conditions for vanishing contrast at a Kossel line (e.g., critical voltage); separation between Kossel line segments at intersections. Examples of application to refinement of structure parameters (zone axis intensities) and structure factor determination (Kossel line methods) are given. The relation of these magnitudes to theory is discussed, especially for the Kossel line methods. These are described in terms of effective Fourier potentials or gaps at the Bloch-wave dispersion surface. Use of the methods for refinement of structure parameters and structure factors is reviewed with special attention to recent developments. This is seen along two lines: 1) extended scope for the more accurate methods in order to cover larger unit cells and 2) better precision in measurements of intensities.

Crystallography↗
PubMed1989

Early diagnosis of postoperative pneumonia following upper abdominal surgery. A study in patients without cardiopulmonary disorder at operation.

In 130 patients with no cardiac or pulmonary disease at the time of elective upper abdominal surgery, chest radiography was performed 2 and 4 days postoperatively. The sputum was examined and the patients were monitored with measurement of body temperature, arterial oxygen tension and white blood counts. Pneumonic infiltrates appeared in 8.4% of the patients and atelectasis in 68.5%. Most of the patients had elevated body temperature, raised white blood count and reduced arterial oxygen tension postoperatively. None of these commonly employed clinical or laboratory findings, singly or in combination, proved adequate for diagnosis of postoperative pneumonia.

Aged↗
PubMed1988

Multiple sclerosis in the Faroe Islands. IV. The lack of a relationship between canine distemper and the epidemics of MS.

Clinical onset of multiple sclerosis (MS) occurred in 32 native resident Faroese between 1943 and 1973, comprising 3 consecutive epidemics of decreasing frequency. Relationship of MS with the appearance of canine distemper (CD) was explored by serologic studies, questionnaires, and veterinarian reports. Tested were sera from 12 MS patients and 112 controls among the 22 patients and 192 controls with questionnaires in 1978-1979. The daily treatment ledgers of the Veterinarian of the Faroes 1940-1961 were also reviewed and additional Faroese interviewed 1987-1988 as to CD. History of CD was determined for residence of all 32 MS. There was no evidence of elevated CD antibody titers in MS vs controls for neutralizing titers or ELISA values, nor to ELISA for measles. In the questionnaires only one patient and 2 of his sibs reported owning (the same) dog(s) with CD during the war. One other patient reported a possibly sick dog but not CD. CD occurred in one southern village 1941-1942, was present on Vágar from 1941-1950, and was epidemic on Streymoy 1944-1945 with scattered cases there and elsewhere through 1950. There was no significant correlation between villages with CD and MS residents. We conclude that the occurrence of multiple sclerosis was not related to the presence of canine distemper or sick dogs in the Faroe Islands.

Animals↗
PubMed1987

The CT (Hounsfield unit) number of brain tissue in healthy infants. A new reliable method for detection of possible degenerative disease.

It is difficult to correlate CT Hounsfield unit (H. U.) numbers from one CT investigation to another and from one CT scanner to another, especially when dealing with small changes in the brain substance, as in degenerative brain diseases in children. By subtracting the mean value of cerebrospinal fluid (CSF) from the mean value of grey and white matter, it is possible to remove most of the errors due, for example, to maladjustments, short and long-term drift, X-ray fan, and detector asymmetry. Measurements of white and grey matter using these methods showed CT H. U. numbers changing from 15 H. U. to 22 H. U. in white matter and 23 H. U. to 30 H. U. in grey matter in 86 healthy infants aged 0-5 years. In all measurements, the difference between grey and white matter was exactly 8 H. U. The method has proven to be highly accurate and reproducible.

Brain↗
PubMed1979

Activation of reticuloendothelial cells following infection with murine cytomegalovirus.

Macrophage and reticuloendothelial system function was investigated in adult, female C3H mice during the course of a nonlethal infection with murine cytomegalovirus (MCMV). Peritoneal macrophages harvested from mice infected three to 21 days previously were tumoricidal in vitro for a syngeneic mammary tumor cell line and showed antiviral activity by suppressing replication of vaccinia virus in a fibroblast monolayer. In addition, macrophages harvested from animals on days 7 and 14 after MCMV infection manifested augmented phagocytosis of yeast particles in vitro. Furthermore, enhanced levels of chemiluminescence were emitted during phagocytosis of zymosan particles by macrophages harvested on days 3 and 7 after MCMV infection. Finally, enhanced protection against Listeria monocytogenes was demonstrated in mice on days 7, 14, and 21 after MCMV infection. These findings support the concept of activation of the reticuloendothelial system during viral infection.

Animals↗
PubMed1979

Prolactin and Leydig cell responsiveness to LH/hCG in the rat.

The effects of prolactin and 2-bromo-alpha-ergocryptine (CB-154) on Leydig cell function in intact and hypophysectomized male rats were studied. The conclusions can be summarized as follows: prolactin (1) has a direct stimulatory effect on the number of LH receptors on rat Leydig cells, (2) has no effect on the characteristics of the dose-response curve of isolated Leydig cells (hCG stimulated androgen production) in vitro even after treatment with pharmacological doses in vivo, and (3) acts synergistically with LH to stimulate the quantity of androgen produced by the Leydig cells in response to hCG in vitro and to increase the sensitivity of the hCG-dose-response curve. Treatment of intact rats with CB-154 reduced the quantity of androgen produced by the Leydig cells in vitro after exposure to hCG and decreased LH binding to the same cells by 50%. These results suggest that under normal conditions, endogenous prolactin plays a key role in maintaining the functional integrity of rat Leydig cells.

Animals↗
PubMed1979

A summary of the prevalence of Parelaphostrongylus tenuis in a captive wapiti population.

A total of 87 brains from harvested and collected wapiti and red deer (Cervus spp.) were examined grossly and microscopically between 1973 and 1977 in a 2104 ha. preserve. Prevalence of infection significantly increased from 26.6% of the sample in 1973 to 64.3% in 1975 (P less than .05). A decline to 47.7% in 1977 (P greater than .05) was not significant. However, the number of clinical cases was significantly higher in 1976-1977 (P less than .02) than previously reported in 1973-1975.

Animals↗