Search PubMed⌕ Search

Biomedical subjects

I Jensen

Publications and source records attributed to I Jensen.

At least 19 recordsLinked to original sources
PubMed2002

Percolation and epidemics in a two-dimensional small world.

Percolation on two-dimensional small-world networks has been proposed as a model for the spread of plant diseases. In this paper we give an analytic solution of this model using a combination of generating function methods and high-order series expansion. Our solution gives accurate predictions for quantities such as the position of the percolation threshold and the typical size of disease outbreaks as a function of the density of "shortcuts" in the small-world network. Our results agree with scaling hypotheses and numerical simulations for the same model.

Biophysical Phenomena↗
PubMed2002

Determinants of undiagnosed asthma.

BACKGROUND: The conformity between asthma diagnosed in a clinical setting and asthma from an epidemiological point of view has not been much studied. METHODS: History, symptoms, and clinical findings in persons with and without a previous physician diagnosed asthma were studied among persons classified as having asthma according to an epidemiological definition. RESULTS: Smoking was more prevalent in persons not diagnosed as having asthma prior to the study (n = 96), than in those with a previous asthma diagnosis (n = 119), (60% vs. 41%, P = 0.006). Positive skin prick test (SPT) was less common (39.6% vs. 58.0%, P = 0.009), lung function expressed as FEV1.0 in percentage of predicted was better (92.1 vs. 85.4, P = 0.018), reversibility to a bronchodilator was smaller (mean reversibility 4.0% vs. 6.2% of predicted, P = 0.003) and symptoms were less frequently reported (P < 0.001) by those who had not a physician diagnosed asthma prior to the study. CONCLUSION: The asthma diagnosis is often overlooked by the medical profession in patients with mild disease. Furthermore, smoking seems to worsen asthma exacerbations in patients with mild disease.

Adult↗
PubMed2002

High prevalence of obesity in asthmatic patients on sick leave.

Obesity and asthma are common chronic diseases in the industrialised world. The aim of the present study was to investigate a possible relationship between asthma and obesity among persons on sick leave due to respiratory disorder. The diagnosis of asthma (n = 237) was made in a three-stage model (questionnaire, telephone interview and clinical examination) in persons on sick leave due to any respiratory disorder. Persons on sick leave due to non-specific spinal pain, (n = 1231) and a general population sample (n = 5092) were used as references. Obesity (body mass index > 30 kg/m2) was found in 20.7% of the asthmatic patients on sick leave compared with 13.7% in the non-specific pain patients on sick leave and in 6.5% of the controls (P < 0.001). It is not clear whether the increased prevalence of obesity among asthmatics reflects a true increase in asthma in obese persons or whether asthma-like symptoms occur because of obesity. Weight reduction schemes and weight maintenance programmes should be important components in treatment and rehabilitation plans for persons with asthma.

Absenteeism↗
PubMed2002

Estimation of in vivo capillary or venous blood glucose concentration from analysis on stored venous blood or its plasma and use in quality control of near-patient glucose tests.

Glucose concentrations were determined in capillary and venous blood and in venous plasma from 100 consecutive patients referred to an oral glucose tolerance test. The capillary blood was immediately transferred to a haemolysing and glucose stabilizing solution and frozen within 4h. Venous blood was drawn in heparin-sodium fluoride tubes and stored for 0, 4 or 24h at 4 or 20 degrees C. Aliquots of the venous blood were then treated in the same way as the capillary blood. The primary tubes were centrifuged, and aliquots of the plasma were stabilized, as described. All specimens from the same sampling event were analysed in the same analytical series on EBIO compact. Deming linear regression equations y = a + bx were calculated to estimate the glucose concentration in one specimen from that in a differently treated specimen e.g.: B(cB:fPt)---Glucose (0h) = 0.61 + 0.897*P(vB;fPt)-Glucose (24h. 20 C). n = 100, SD(y/x) = 0.25 mmol/L and B(vB) Glucose (0h) = 0.53 + 0.897*P(vB)--Glucose (24h. 20 degrees C), n = 196, SD(y/x) = 0.26 mmol,/L. The non-analytical part of the standard deviation of the ratio between the near-patient test result and its predicted value was 0.038 for both of the above predictions. In conclusion, the analytical (including sampling) variation of near-patient tests of glucose can be assessed by laboratory analysis on mailed, heparin-fluoride stabilized venous blood or on plasma samples made from the mailed blood.

Adult↗
PubMed2001

The association between exposure to a rear-end collision and future health complaints.

Different symptoms, together with neck pain, have been attributed to persons with persistent complaints after a previous motor vehicle crash (MVC) and are sometimes referred to as the "late whiplash syndrome." A cohort study was conducted to determine whether exposure to a rear-end collision, with or without whiplash injury, is associated with future health complaints. The results regarding future neck or shoulder pain have previously been described, and the objective of the present report was to focus on outcomes other than neck pain. Included in the study were persons 18 to 65 years of age and covered by traffic insurance at one of the largest insurance companies in Sweden. Claim reports were collected from the period November 1987 to April 1988. Drivers exposed to a rear-end collision were divided into two subgroups: those with reported whiplash injury (n = 232) and those without reported whiplash injury (n = 204). For comparison, 3688 subjects who were unexposed to MVCs were selected, with consideration taken to the age and gender distribution in the exposed subgroups. The prevalence of different health complaints among the study subjects was estimated according to a mailed questionnaire at follow-up in 1994, 7 years after the rear-end collision. When exposed subjects with whiplash injury were compared to unexposed subjects, increased relative risks in the range of 1.6-3.7 were seen for headache, thoracic and low back pain, as well as for fatigue, sleep disturbances and ill health. No corresponding increased risks were found among the exposed subjects without reported whiplash injury. We conclude that rear-end collisions resulting in reported whiplash injuries seem to have a substantial impact on health complaints, even a long time after the collision. There is a need to identify factors that predict a non-favorable outcome in order to improve clinical management.

Accidents, Traffic↗
PubMed2001

No significant differences between intervention programmes on neck, shoulder and low back pain: a prospective randomized study among home-care personnel.

The effects of two different prevention programmes on: (1) reported neck, shoulder and back pain, (2) perceived physical exertion at work and perceived work-related psychosocial factors, were evaluated by questionnaires after 12 and 18 months. Female nursing aides and assistant nurses (n = 282) working in the home-care services, were randomly assigned to one of three groups for: (1) individually designed physical training programme, (2) work-place stress management, (3) control group. Results revealed no significant differences between the three groups. However, improvements in low back pain were registered within both intervention groups for up to 18 months. Perceived physical exertion at work was reduced in the physical training group. Improvements in neck and shoulder pain did not differ within the three groups. Dissatisfaction with work-related, psychosocial factors was generally increased in all groups. As the aetiology of neck, shoulder and back disorders is multifactorial, a combination of the two intervention programmes might be preferable and should be further studied.

Adult↗
PubMed2000

An efficient solid-phase strategy for the construction of chemokines.

Synthesis of chemokines via stepwise SPPS approaches has been shown to be a challenge. Herein, a complete study of different coupling methods, solvents and temperature combined with a continuous-flow synthesizer equipped with feedback monitoring was carried out. The results from this study indicate that this family of molecules can be prepared using an Fmoc/Bu(t) chemical approach and provide a general method to apply for the elongation of other difficult sequences.

Amino Acid Sequence↗
PubMed2000

Dynamic cell cycle kinetics in vitro and in vivo in myelodysplastic syndromes with special reference to the influence of hematopoietic growth factors.

We have investigated the effect of HGF in vivo and in vitro in MDS using a recently developed FCM assay involving the simultaneous measurement of cell surface antigens, DNA content, and BrdUrd or IodUrd incorporation. This allows for the determination of the dynamic cell kinetic parameters: LI, T(s), and T(pot) and we observed that in vitro HGF stimulation resulted in a significant decrease in mean T(pot) values from 6.6 to 3.5 days. Importantly, we demonstrated that in vivo GM-CSF administration to patients with RAEB resulted in a shortening of T(pot) within the 2 first weeks of GM-CSF treatment.

Aged↗
PubMed2000

The association between exposure to a rear-end collision and future neck or shoulder pain: a cohort study.

Neck pain is the most frequently reported feature in connection with whiplash injury, but it is also a common complaint in the general population. Therefore it is crucial to include an unexposed comparison group when evaluating the association between neck pain and a previous motor vehicle crash (MVC). To determine whether exposure to a rear-end collision, without or with whiplash injury, is associated with future neck or shoulder pain, a cohort study was conducted. The study population consisted of persons covered by traffic insurance at one of the largest insurance companies in Sweden. Claim reports were collected from the period November 1987 to April 1988. Drivers exposed to a rear-end collision were divided into two subgroups, without reported whiplash injury (n = 204) and with reported whiplash injury (n = 232). Two comparison groups, unexposed to MVCs, consisting of 1599 and 2089 persons, were selected with consideration taken to the age and gender distribution in the exposed subgroups. A questionnaire concerning neck or shoulder pain and other subjective health complaints was mailed to all the study subjects at follow-up in 1994, 7 years after the rear-end collision. The relative risk of neck or shoulder pain at follow-up was 1.3 (95% CI 0.8-2.0) in the exposed subjects without whiplash injury compared with the unexposed. The corresponding relative risk in subjects with whiplash injury was 2.7 (95% CI 2.1-3. 5). We conclude that there is no increased risk of future neck or shoulder pain in drivers who did not report whiplash injury in connection with a rear-end collision 7 years earlier. In drivers with reported whiplash injury, the risk of neck or shoulder pain 7 years after the collision was increased nearly three-fold compared with that in unexposed subjects.

Accidents, Traffic↗
PubMed1999

Intra- and inter-rater reliability of an 11-test package for assessing dysfunction due to back or neck pain.

BACKGROUND AND PURPOSE: The intra- and inter-rater reliability of 11 tests assembled by physiotherapists for clinical purposes was investigated. Forty-five patients and 23 healthy volunteers participated in the study. METHOD: Twenty-one patients were tested simultaneously and independently by two physiotherapists to determine inter-rater reliability for two raters. Twenty-four patients and 11 healthy volunteers were tested by one physiotherapist three times in a week to determine intra-rater reliability over time. Twelve healthy volunteers were tested by three different physiotherapists in a week to determine inter-rater reliability for three raters. RESULTS: Inter-rater agreement for two simultaneous raters was clinically acceptable. Repeatability on three test occasions was clinically acceptable in six of the 11 tests. There were no systematic differences between occasions. CONCLUSIONS: Intra- and inter-rater reliability was acceptable for six of the 11 tests in the form described here: three gait tests, two functional lifting tests and a functional muscular endurance test in the right leg. If these tests are to be used as outcome measures, account must be taken of the size of the typical fluctuation in measurements shown. The repeatability figures given may be used as guidelines for interpreting the clinical value of possible changes in test values.

Adult↗
PubMed1998

Human and mouse Gpi1p homologues restore glycosylphosphatidylinositol membrane anchor biosynthesis in yeast mutants.

Glycosylphosphatidylinositol (GPI) represents an important anchoring molecule for cell surface proteins. The first step in its synthesis is the transfer of N-acetylglucosamine (GlcNAc) from UDP to phosphatidylinositol (PI). The products of three mammalian genes, PIG-A, PIG-C and PIG-H, have previously been shown to be involved in the putative enzymic complex. Here we report the cloning of human and mouse cDNAs encoding a fourth participant in the GlcNAc transfer reaction which are homologues of the Saccharomyces cerevisiae and Schizosaccharomyces pombe Gpi1 proteins. To provide evidence for their function, these proteins were expressed in GPI1-disrupted yeast strains. In Sacch. cerevisiae, where GPI1 disruption results in a temperature-sensitive phenotype and abolishes in vitro GlcNAc-PI synthesis, restoration of growth could be demonstrated in a temperature-dependent manner. In addition, in vitro GlcNAc-PI synthetic activity was again detectable. In Schiz. pombe, gpi1+ disruption is lethal. Using random spore analysis, we were able to show that the mammalian GPI1 homologues can rescue haploids harbouring the lethal gpi1+::his7+ allele. Our data demonstrate that the genes identified are indeed involved in the first step of GPI biosynthesis, and allow conclusions about a specific function for Gpi1p in stabilizing the enzymic complex. The finding that, despite a low degree of identity, the mammalian Gpi1 proteins are able to participate in the yeast GlcNAc-PI synthetic machinery as heterologous components further demonstrates that GPI biosynthesis has been highly conserved throughout evolution.

Amino Acid Sequence↗
PubMed1998

[Spread and control of methicillin resistant Staphylococcus aureus in a department of dermatology].

Patients with skin diseases caused a spread of methicillin-resistant Staphylococcus aureus (MRSA) to 17 patients in our Department of Dermatology, because of their heavily scaly skin. Patients with severe dermatosis are regularly treated with dicloxacillin. The resistance of bacteria strain concerned suggests a selection because of the use of dicloxacillin in the Department. The strain is sensitive to gentamicin, which differentiates it from strains imported from abroad. Increased hygienic precautions, isolation of infected patients, staff and management efforts and a close contact with the microbiologists prevented MRSA from spreading to other hospital wards.

Aged↗
PubMed1998

Human umbilical vein endothelial cells lack expression of the estrogen receptor.

Estrogens may influence the expression of various cytokines, adhesion molecules, von Willebrand factor and prostacyclin produced by endothelial cells. However, reports concerning expression of the estrogen receptor in endothelial cells are controversial. Primary human umbilical vein endothelial cells (HUV-EC), the non continuous human umbilical vein endothelial cell line HUV-EC-C (ATCC CRL 1730) and endothelial cells from 10 frozen umbilical cords were analyzed for the expression of the estrogen receptor. Immunological studies using estrogen receptor specific antibodies failed to detect the expression of the receptor in all human umbilical vein endothelial cells tested. No estrogen receptor transcripts were found in primary HUV-EC or HUV-EC-C by reverse transcriptase-polymerase chain reaction. Weak hybridization signals were detected when the PCR amplicons were hybridized with estrogen receptor cDNA sequences as a probe. In vitro protein-DNA interaction studies revealed no complexes between a fully consensus estrogen response element and HUV-EC-C extracts. Finally, transient transfection studies in HUV-EC-C could not demonstrate 17beta-estradiol-induced transcription of the beta-galactosidase reporter gene linked to a consensus estrogen response element. These observations suggest that human umbilical vein endothelial cells lack the estrogen receptor.

Blotting, Western↗
PubMed1997

Fate of insulin analogs in intact and nephrectomized rats determined by their receptor binding constants.

After intravenous injection of 125I-labeled human insulin and analogs in normal and nephrectomized rats, we examined their kinetic fate by Q-Sepharose separation into intact ligand, "fragments" (genuine fragments and protein-bound radioactivity), and iodide. Receptor binding association and dissociation constants (kass and kdis, respectively) of the analogs were estimated dynamically in vitro by BIAcore. The very fast disappearance of intact ligand from serum was found to be determined by 1) both kass and kdis of receptor-bearing tissue, thus substantiating our primary hypothesis; 2) elimination by kidneys, and 3) fast extravascularization. The rate of appearance of degradation products from receptor-mediated intracellular processing seems determined by kdis. With the possible exception of a truncated analog, ligand appears protected against degradation while the intracellular receptor-ligand complex remains intact. Non-receptor-mediated processing in kidneys is slow, compared with the receptor-mediated uptake and degradation of ligands with rate constants comparable to those of insulin. We observed binding of insulin and analogs putatively to serum proteins; binding capacity and affinity appeared insignificant for insulin but considerable for some analogs.

Animals↗
PubMed1996

A 6-month prospective study of hospital-acquired bacteremia in Copenhagen county.

During a 6-month period, 892 positive blood cultures were detected in the Copenhagen County hospitals. 302 (34%) were regarded as contaminations, and of the remaining cases 419 (71%) were community-acquired and 171 (29%) hospital-acquired, giving incidence rates of 6.8/1,000 admissions and 2.8/1,000 admissions, respectively. Both frequency and rate of hospital-acquired bacteremia were lower compared to most other studies. E. coli was more commonly found in community-acquired infections, while coagulase-negative staphylococci were the organisms most often considered as a contaminant. The main causative organisms in hospital-acquired infections were S. aureus (n = 37) and E. coli (n = 34). The proportion of polymicrobial bacteremias in this study was lower compared to most other studies (8%). E. coli from hospital-acquired infections were resistant to ampicillin in 42% of cases, but other Enterobacteriaceae showed higher percentage of resistance to beta-lactam antibiotics. S. aureus was penicillin-resistant in 92% of cases, but no methicillin-resistant strains were isolated. The frequency of antibiotic resistance was low compared to reports from other countries. A total of 136 hospital-acquired cases were followed prospectively. 61% of the patients were male and 46% were > or = 60 years of age. Most patients had predisposing diseases, 90% had foreign body and/or recent surgery performed, and 74 (54%) had an intraveneous catheter. The portal of entry was known in 132 (97%) of the cases, the most common being the urinary tract (42%), followed by an intravenous catheter (30%). The prevalence of urinary tract catheters gave an increased number of cases with E. coli bacteremia. The mortality was 16%.

Adolescent↗