PubMed Health⌕ Search

Biomedical subjects

L Mortensen

Publications and source records attributed to L Mortensen.

At least 19 recordsLinked to original sources

Environmental changes in the North Atlantic Region: SCANNET as a collaborative approach for documenting, understanding and predicting changes.

The lands surrounding the North Atlantic Region (the SCANNET Region) cover a wide range of climate regimes, physical environments and availability of natural resources. Except in the extreme North, they have supported human populations and various cultures since at least the end of the last ice age. However, the region is also important at a wider geographical scale in that it influences the global climate and supports animals that migrate between the Arctic and all the other continents of the world. Climate, environment and land use in the region are changing rapidly and projections suggest that global warming will be amplified there while increasing land use might dramatically reduce the remaining wilderness areas. Because much of the region is sparsely populated--if populated at all--observational records of past environmental changes and their impacts are both few and of short duration. However, it is becoming very important to record the changes that are now in progress, to understand the drivers of these changes, and to predict future consequences of the changes. To facilitate research into understanding impacts of global change on the lands of the North Atlantic Regions, and also to monitor changes in real time, an EU-funded network of research sites and infrastructures was formed in 2000: this was called SCANNET--SCANdinavian/North European NETwork of Terrestrial Field Bases. SCANNET currently consists of 9 core sites and 5 sites within local networks that together cover the broad range of current climate and predicted change in the region. Climate observations are well replicated across the network, whereas each site has tended to select particular environmental and ecological subjects for intensive observation. This provides diversity of both subject coverage and expertise. In this paper, we summarize the findings of SCANNET to-date and outline its information bases in order to increase awareness of data on environmental change in the North Atlantic Region. We also identify important gaps in our understanding and identify where the roles of existing infrastructures and activities represented by SCANNET can facilitate future research, monitoring and ground-truthing activities.

Agriculture↗

The prevalence of antibiotic resistance in bacterial respiratory pathogens from Norway is low.

OBJECTIVES: To determine the degree of bacterial susceptibility to the most commonly used drugs for respiratory infections in Norway, and to find if bacterial resistance is emerging. METHODS: Clinical isolates of Streptococcus pneumoniae, Haemophilus influenzae and group A streptococci from respiratory tract specimens and from the eye were collected from different parts of Norway during two study periods. During the first period (1993-1994), three laboratories, covering 15% of the Norwegian population, participated. During the second study period in 1997, five laboratories, covering 27% of the population, collected respiratory isolates. In total, 494 isolates of S. pneumoniae, 696 isolates of H. influenzae and 694 isolates of group A streptococci were included in the study. The study population comprised children and adults attending hospital and general practice. Bacterial susceptibility was determined by the E test, and breakpoints were according to the National Committee for Clinical Laboratory Standards (NCCLS). RESULTS: The prevalence of bacterial resistance was low, and we observed no significant increase in bacterial resistance between the two study periods. In 1997, only 0.6% of pneumococci had decreased susceptibility to penicillin, 1.6% of group A streptococci were resistant to erythromycin, and 6.7% of all isolates of H. influenzae produced beta-lactamase. CONCLUSIONS: The prevalence of antibiotic resistance in respiratory pathogens in Norway is low.

Adult↗

Evaluation of 12 commercial tests for detection of Epstein-Barr virus-specific and heterophile antibodies.

Ten microbiological departments in Norway have participated in a multicenter evaluation of the following commercial tests for detection of Epstein-Barr virus (EBV)-specific and heterophile antibodies: CAPTIA Select viral capsid antigen (VCA)-M/G/EBNA (Centocor Inc.), Enzygnost anti-EBV/immunoglobulin M (IgM) and IgG (Dade Behring), Vironostika EBV VCA IgM/IgG/EBNA enzyme-linked immunosorbent assay (ELISA) (Organon Teknika), SEROFLUOR immunofluorescence assay and EBV Combi-Test (Institute Virion Ltd.), anti-EBV recombinant IgM- and IgG-early antigen/EBNA IgG ELISA (Biotest Diagnostics), EBV IgM/IgG/EBNA ELISA (Gull Laboratories), Paul-Bunnell-Davidsohn test (Sanofi Diagnostics Pasteur), Monosticon Dri-Dot (Organon Teknika), Avitex-IM (Omega Diagnostics Ltd.), Alexon Serascan infectious mononucleosis test (Alexon Biomedical Inc. ), Clearview IM (Unipath Ltd.), and Cards+/-OS Mono (Pacific Biotech, Inc.). The test panel included sera from patients with primary EBV infection, immunocompromised patients with recent cytomegalovirus infection, healthy persons (blood donors), and EBV-seronegative persons. Among the tests for EBV-specific antibodies the sensitivity was good, with only small differences between the different assays. However, there was a greater variation in specificity, which varied between 100% (Enzygnost) and 86% (Biotest). Tests for detection of heterophile antibodies based on purified or selected antigen (Avitex, Alexon, Clearview IM, and Cards+/-OS Mono) were more sensitive than the Paul-Bunnell-Davidsohn and Monosticon tests.

Antibodies, Viral↗

[Practical approach to otitis media with methicillin-resistant yellow Staphylococci].

Methicillin-resistant Staphylococcus aureus (MRSA) are multiresistant bacteria, known to cause nosocomial infections. We present a report on a two and a half year-old, recently adopted, child, who suffered from otitis media with discharge. The child was treated with penicillin in Norway without success. Culture revealed methicillin-resistant S aureus. Methicillin-resistant S aureus were also found in the noses of the adoptive parents. After a second unsuccessful course of antibiotics the child was admitted to the Ear, nose, and throat department and was subsequently treated with intravenous vancomycin, mastoidectomy and eradication of the nasal methicillin-resistant S aureus carriage. The admittance to the Ear, nose, and throat department was carefully planned. All departments concerned were thoroughly briefed. The patient was given vancomycin intravenously for 18 days, partly as an out-patient. Subsequent control cultures from the patient and the adoptive parents have all been negative. No one dealing with the patient has been infected. The case illustrates the importance of thorough planning and co-operation between different departments.

Anti-Bacterial Agents↗

Positive effects of physiotherapy on chronic pain and performance in osteoporosis.

The aim of this placebo-controlled, randomized, single-masked study was to establish the effects of a 10-week ambulatory exercise programme for osteoporotic patients on pain, use of analgesics, functional status, quality of life, balance and muscle strength. Fifty-three ambulatory postmenopausal women with at least one spinal crush fracture and pains within the last 3 years were randomized for physiotherapeutic training twice a week for 10 weeks or no training. The training included general training of balance and muscle strength, with stabilization of the lumbar spine. The participants were tested at baseline, week 5 and week 10 with a balance test, muscle strength test and questionnaires on pain, use of analgesics, functional status and quality of life. Twelve weeks after the supervised training had finished (week 22) they answered the same questionnaires. The study groups were comparable at baseline. The training group had a significant reduction in use of analgesics (p = 0.02) and pain level (p = 0.01) during the training period. Distribution of functional score improved; the improvement was reduced at week 22. Quality of life score improved significantly throughout the study (p = 0.0008), even after week 22. Balance improved non-significantly (p = 0.08). Quadriceps muscle strength improved significantly after 5 weeks (p = 0.04). Back extensor muscle strength improved almost significantly (p = 0.09). In conclusion, this training programme for osteoporotic patients improved balance and level of daily function and decreased experience of pain and use of analgesics. Quality of life was improved even beyond the active training period.

Aged↗

Risedronate increases bone mass in an early postmenopausal population: two years of treatment plus one year of follow-up.

This double-blind, placebo-controlled study was undertaken to determine 1) the efficacy of oral risedronate for prevention of bone loss in healthy, early postmenopausal patients with normal bone mass, 2) the effect on bone mass when treatment was stopped, and 3) the safety and tolerance of risedronate in this population. A group of 111 patients were randomized to oral placebo, risedronate 5 mg daily, or risedronate 5 mg cyclically, for 2 yr followed by 1 yr off treatment. Measurements included percentage change from baseline in lumbar spine bone mineral density (BMD) at 24 months; percentage change from baseline in BMD of the femoral neck, trochanteric region, and Ward's triangle region of the proximal femur; and changes in biochemical markers of bone turnover. After 2 yr, there was a mean increase in BMD of the lumbar spine of 1.4% from baseline and of 5.7% vs. placebo in the risedronate 5 mg daily group. There were decreases from baseline in BMD of 1.6% and 4.3% in the risedronate 5 mg cyclic and placebo groups, respectively. By the end of 24 months, trochanteric bone mass at the hip increased by 5.4% in the risedronate 5 mg daily group and by 3.3% in the risedronate 5 mg cyclic group vs. placebo. Bone mass was maintained at the femoral neck in the 2 active-treatment groups vs. a 2.4% mean loss with placebo. During the treatment-free follow-up, bone turnover increased toward baseline in both risedronate groups. By the end of that year, lumbar spine bone mass in all 3 groups was lower than at baseline. Oral risedronate was well tolerated. We conclude that risedronate (5 mg daily) increases bone mass and risedronate (5 mg cyclic) appears to prevent bone loss in early postmenopausal women with normal BMD.

Adult↗

Effect of vitamin D treatment in hypoparathyroid patients: a study on calcium, phosphate and magnesium homeostasis.

AIM: This study was undertaken to examine the effects of long-term vitamin D treatment on calcium, phosphate and magnesium homeostasis at organ level in hypoparathyroid patients. METHODS: Fifteen vitamin D-treated hypoparathyroid patients were studied, eight of the patients in a combined 47Ca kinetic and calcium, phosphate and magnesium balance study. Results were compared with a matched control group of 12 normal individuals. RESULTS: All the patients had normal serum levels of calcium, phosphate and magnesium. Absolute intestinal calcium absorption was increased (P < 0.0001). Urinary calcium excretion was normal, but active tubular calcium reabsorption (TmCa/glomerular filtration rate) was low (P< 0.001). Bone resorption rates and bone mineralization rates were very low (P < 0.001 and P < 0.05). Twenty-four-hour urinary hydroxyproline excretion and serum cross-linked carboxyterminal telopeptide of type I were in the upper normal range. Serum alkaline phosphatase was normal, but serum carboxyterminal propeptide of human type I procollagen and serum osteocalcin were significantly reduced (P < 0.05). Calcium balance was positive and significantly different from controls (P < 0.001). All parameters from phosphate homeostasis were normal. Intestinal magnesium absorption was low though not significantly different from normal (P = 0.06). Urinary excretion of magnesium was not significantly higher than normal, but renal magnesium reabsorption was reduced (P <0.001). Magnesium balance was low, though the difference was not significant (P < 0.06). CONCLUSION: Long-term vitamin D treatment in hypoparathyroid patients resulted in a positive calcium balance. Bone turnover was very low. Results of bone markers and resorption rate were conflicting. Vitamin D treatment apparently normalized the abnormalities previously found in phosphate homeostasis of hypoparathyroid patients. Magnesium homeostasis was disturbed, with a more negative balance compared with normal subjects, implying a state of magnesium deficiency in these patients.

Adult↗

Responses of spring wheat (Triticum aestivum L.) to ozone produced by either electric discharge and dry air or by UV-lamps and ambient air.

The aim of the present study was to examine if ozone produced similar effects on spring wheat growth with and without small amounts of nitrogen oxides. Two methods were used to produce ozone: the first method consisted of dry pressurized air fed to an electric discharge generator generating the byproducts, N2O5 and N2O, the second method consisted of ambient air fed to UV-lamps. Two spring wheat cultivars (Triticum aestivum L. cvs Minaret and Eridano) were exposed in small open-top chambers to charcoal-filtered air, non-filtered ambient air, and non-filtered ambient air with the addition of ozone for 8 h (0900 to 1700 h) daily, for five weeks. Plants were harvested every week. The growth of Minaret was shown to be more sensitive to O3 than that of Eridano. Leaf senescence increased with increasing ozone level in both cultivars. The total above-ground biomass dry weight decreased with increasing ozone concentration in Minaret, but not in Eridano. The Minaret plants reacted with more damaged leaf dry weight and inhibition of growth when O3 was produced by UV-lamps than when O3 was produced by air fed to an electric discharge generator. This could be explained by more nitrogen content per plant but not by increased nitrogen concentration in plant tissue in plants exposed to increased O3 and small amounts of incidental nitrogen oxides.

Journal Article↗

Bone histomorphometry in hypoparathyroid patients treated with vitamin D.

Parathyroid hormone (PTH) and vitamin D are both active regulators of bone remodeling. Several studies, mostly in animals and in vitro, have suggested that the two hormones act synergistically or interdependently. The aim of the present study was therefore to describe the actions of vitamin D alone on bone remodeling in the absence of circulating PTH. Bone biopsies were obtained from 12 patients with vitamin D-treated hypoparathyroidism and from 13 age- and gender-matched normal controls. Mean total resorption rate was reduced (0.9 vs. 3.8 mu m/day,p < 0.001), the resorption period was prolonged (80.8 vs. 25.7 days, p < 0.001), and the resorption depth was reduced (41.7 vs. 55.3 mu m, p < 0.001). The fractional active and the total eroded surface were not significantly reduced. The fractional formation surface was reduced (5.2 vs. 12.5 mu m, p < 0.001). Trends toward prolongation of the formation period and reduction of the final wall thickness were found. The balance between resorption depth and final wall thickness was not significantly different from normal (0.96 vs. -4.4 mu m). The quiescent period was prolonged (7.6 vs. 1.7 years, p < 0.001) and the activation frequency was reduced (0.13 vs. 0.6 year(-1), p < 0.001). The structural parameters, trabecular bone volume, trabecular thickness, marrow space star volume, and trabecular star volume, remained unchanged. In the absence of PTH, Vitamin D alone is not able to normalize bone resorption and bone turnover in hypoparathyroid patients.

Adult↗

Bioavailability of calcium supplements and the effect of Vitamin D: comparisons between milk, calcium carbonate, and calcium carbonate plus vitamin D.

Our aim was to examine a regimen for calcium supplementation because various factors seem to be important for its bioavailability, and to examine the effect of adding vitamin D to the supplement. The participants were 20 healthy women aged 28-59 y (chi: 38 y). During the 3-d periods and 1 d before, the participants were consuming a calcium and energy-balanced diet as similar to their usual daily diet as possible. The study was designed as a randomized, placebo-controlled, partly blinded crossover study divided into four periods of 3 d each: 1) three tablets containing 1000 mg CaCO3/d, 2) three tablets containing 1000 mg CaCO3 plus 5 micrograms (200 IU) vitamin D/d, 3)1 L more milk than in the usual daily diet, and 4) three placebo tablets daily. Bioavailability of the different calcium-supplement regimens were evaluated by changes in 24-h urinary excretion of calcium, phosphate, and magnesium. A significant increase in urinary calcium excretion was found during all periods of supplementation compared with the placebo period (P<0.01). Excretion of calcium in the calcium carbonate period was not significantly higher that that in the milk period, but calcium carbonate plus vitamin D resulted in significantly higher calcium excretion compared with that in the milk period. We conclude that the examined calcium carbonate regimen is at least as good a calcium supplement as milk, and that addition of 600 IU vitamin D/d promptly resulted in an increase in urinary calcium excretion after an increase in calcium absorption, even in healthy women.

Adult↗

Effects of ozone on 14C translocation velocity and growth of spring wheat (Triticum aestivum L.) exposed in open-top chambers.

Growth and yield were reduced but (14)C translocation velocity was not affected by increasing levels of ozone in spring wheat exposed in open top chambers to the following treatments: charcoal filtered air (CF), non-filtered ambient air (NF), or NF with addition of 30 microl litre(-1) ozone, 8 h daily (NFO). Destructive harvests were performed at anthesis and at maturity. Parts of the flag leaf or the second leaf were exposed to (14)CO(2) in small cuvettes for 5 min before, during and after anthesis. The translocation velocity was followed by autoradiography and scintillation counting of the plants frozen and lyophilized at different times after labelling. The label was transported at the same velocity in all the treatments. Ozone induced changes in carbon allocation or partitioning should probably be explained as amounts of carbon transported (mg s(-1)), rather than as transportation velocity (mm s(-1)). The amount translocated may be governed by source conditions under O(3) stress: reduced healthy green biomass and photosynthesis, but perhaps also by impairment of phloem loading because of membrane damage.

Journal Article↗

Total number of particles in a bounded region estimated directly with the nucleator: granulosa cell number in ovarian follicles.

OBJECTIVE: Our objective was to evaluate the precision of the "nucleator" with regard to estimation of the number of granulosa cells in individual follicles and the average number of granulosa cells per follicle in a group of follicles. STUDY DESIGN: Nine murine ovarian follicles embedded in plastic were oriented isotropically with the "orientator" by Mattfeldt, cut into 20 microns serial sections, and stained with hematoxylin. In each follicle the number of granulosa cells was estimated in two ways, both unbiased: (1) with the nucleator principle in the section that contains the nucleolus of the oocyte and (2) in the complete set of follicle sections with the "fractionator" principle. Estimates with the fractionator were interpreted as "true" values. Therefore the precision (CE) of the nucleator estimates could be calculated. RESULTS AND CONCLUSION: The nucleator provides precise estimates of the number of granulosa cells in one complete follicle: CE = 0.12. The amount of effort is minimal, because estimation is based on roughly 50 granulosa cells. The precision of the procedure with regard to estimation of the average number of granulosa cells in a group of follicles depends mainly on the biologic variation (CVbiol = 0.71).

Animals↗

Effects of air pollutants on the growth and antioxidative system of Norway spruce exposed in open-top chambers.

Grafted Norway spruce trees were subjected to exposure beginning in April 1988, to one of four different air treatments in open-top chambers: Charcoal filtered air (CF), non-filtered air (NF), non-filtered air with the addition of O(3) during summer (NFO), and SO(2) plus NO(2) during winter (NFOSN). CF trees were considered as the reference group. No effects on growth parameters were observed. Samples of the two youngest needle year classes were taken late in November 1989 for enzyme determinations. The activity of ascorbic acid peroxidase (A-POD) increased the same level in all treatments, and activities of catalase and dehydroascorbic acid reductase (DHA-R) increased only in NF and NFO treatments. A higher level of activity in the NFOSN treatment was observed only for glucose-6-phosphate-dehydrogenase (Glc-6-P-DH) and non-specific peroxidase (POD). Isoelectric focusing of POD showed a changed pattern in the NFOSN treatment. Neither activity nor isoelectric focusing of superoxidase dismutase (SOD) was changed in any of the treatments.

Journal Article↗

Distribution of hydroxylated vitamin D metabolites [25OHD3 and 1,25(OH)2D3] in domestic pigs: evidence that 1,25(OH)2D3 is stored outside the blood circulation?

1. The distribution of 25-hydroxycholecalciferol (25OHD3) and 1,25-dihydroxycholecalciferol [1,25(OH)2D3] in various organs from domestic pigs was examined by HPLC. 2. Plasma levels of both metabolites corresponded to those found in healthy human subjects. 3. Tissue concentrations of 25OHD3 in fat, kidney, liver, and intestinal mucosa were low (< 1/3 of plasma levels), whereas tissue concentrations of 1,25(OH)2D3 exceeded plasma levels by factors 3-7, adipose tissue concentrations being the highest. 4. Substantial amounts of activated vitamin D are stored outside the blood-streams and may actively participate in vitamin D and calcium homeostasis.

Animals↗

Treatment of psoriasis vulgaris with topical calcipotriol has no short-term effect on calcium or bone metabolism. A randomized, double-blind, placebo-controlled study.

The purpose of this double-blind, placebo-controlled study was to examine whether the vitamin D analogue calcipotriol, topically applied to psoriatic skin lesions, had any effect on calcium or bone metabolism. Thirty-four outpatients with psoriasis vulgaris were randomized to treatment with either calcipotriol ointment (50 micrograms/g) or vehicle ointment twice daily for 3 weeks. The patients were put on a calcium energy fixed diet and examined once weekly. The mean amount of calcipotriol ointment used was 40.3 g/week (range 8.2-95.4 g/week). The results of biochemical markers on calcium and bone metabolism showed no significant differences between the two groups. No correlation was found between the amount of ointment used and changes in parameters on calcium and bone metabolism during the 3-week treatment. It is concluded that calcipotriol ointment (50 micrograms/g), applied in doses of 8.2-95.4 g/week for 3 weeks to psoriatic skin lesions, has no effect on calcium or bone metabolism.

Administration, Cutaneous↗

Lithium stimulates the first meiotic division in mouse oocytes.

Cumulus enclosed oocytes, cumulus enclosed oocytes denuded of their cumulus and cumulus free oocytes from 21 day old unstimulated mice were cultured for 18 hours in control medium supplemented with lithium chloride, dbcAMP and forskolin at various concentrations. In control medium 66% of the cumulus enclosed oocytes, 93% of the denuded oocytes, and 94% of the cumulus free oocytes resumed meiosis (germinal vesicle breakdown), whereas the levels of polar body formation were 27%, 12% and 39%, respectively. In the presence of lithium significantly more cumulus enclosed oocytes and cumulus free oocytes resumed meiosis and formed a polar body, whereas lithium had no effect on the denuded oocytes. Forskolin and dbcAMP stimulated resumption of meiosis and cumulus expansion in the cumulus enclosed oocytes and inhibited resumption of meiosis in the cumulus free oocytes. Lithium more or less eliminated this inhibitory effect of both forskolin and dbcAMP in the cumulus free oocytes. The results indicate (i) that activation of the cAMP second messenger path in the cumulus cells induces them to synthesize a meiosis inducing substance(s) which stimulates the oocyte to resume meiosis, and (ii) that other second messenger systems than the cAMP pathway, e.g. the phosphatidylinositol cycle, are involved in resumption of meiosis and polar body formation. We conclude that lithium enhances the capability of mouse oocytes for resumption of meiosis and polar body formation.

Animals↗

Back transporting infants from neonatal intensive care units to community hospitals for recovery care: effect on total hospital charges.

Many neonates are referred to neonatal intensive care units (NICUs) for specialized care far from their parents' residence. This distance can add to the stress of the parents and reduce the contact of the parents with their newborn. Small studies have found that back transporting these neonates to hospitals closer to their homes is safe and cost-effective. Despite these findings, the reluctance of many insurers to pay for back transports prevents or delays many back transports. Insurers may not consider the findings of the previous studies to be conclusive, given that the comparisons were between small numbers of neonates back transported and neonates who remained in tertiary care, and the potential for differences in severity of illness between the groups is significant. In this study the effect on hospital charges of back transports was examined by comparing the charges for care in community hospitals with what these charges would have been in a tertiary care center. The advantage of this method is that it avoids case-mix differences between the groups and thus minimizes the potential for small-sample bias. Data were collected for all back transports from a NICU to non-tertiary care centers (n = 90) for a 9-month period. We were able to obtain the itemized bills for the care at community hospitals for 42 of these patients. Each bill was recalculated using the charges for the NICU to determine potential for savings. The average charges for recovery care were about $6200 lower at the community hospital than they would have been at the NICU.(ABSTRACT TRUNCATED AT 250 WORDS)

Convalescence↗