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Biomedical subjects

S O Larsen

Publications and source records attributed to S O Larsen.

At least 19 recordsLinked to original sources

Time-resolved immunofluorometric assay of pregnancy-associated plasma protein A in maternal serum screening for Down's syndrome in first trimester of pregnancy.

A low maternal serum concentration of pregnancy associated plasma protein-A (MS-PAPP-A) in the first trimester has been suggested as a marker for the presence of a Down's syndrome (DS) fetus. We developed a time-resolved immunofluorometric assay (TrIFMA) for PAPP-A with a sensitivity < 3.9 mIU/l. In the 7-12 gestational weeks interval the median multiples of the median (MoM) was 0.57 (95%-confidence interval; 0.47-0.99) in DS pregnancies (n = 29) and lower than in controls (n = 223) (P < 0.005). The efficiency of MS-PAPP-A alone was evaluated using empirical receiver-operator-characteristics (ROC) and a sensitivity of about 25% was found for a false-positive rate of about 10% in the 7-12 gestational weeks interval. In parameterized ROC analysis a sensitivity of 9% was found for a false-positive rate of 5%. The TrIFMA PAPP-A assay seems to fulfil the quality criteria for an assay to be used in large-scale serum screening for Down's syndrome.

Down Syndrome

Epidemiology of classic Kaposi's sarcoma in Denmark between 1970 and 1992.

BACKGROUND: Studies have suggested that the incidence of classic Kaposi's sarcoma (KS) varies considerably within Europe. The epidemiology of classic KS in Denmark was described for the period between 1970 and 1992 and association with marital status and country of origin were evaluated. METHODS: A descriptive epidemiology study was carried out using data from the Danish Cancer Registry and from all Danish pathology departments. The effects of marital status and of immigration were evaluated in a case-control study with sex- and age-matched controls for 50 cases of classic KS. RESULTS: A total of 59 patients with classic KS, 34 men, 25 women, were identified between 1970 and 1992, yielding world standardized incidence rates of 0.40 and 0.22 per 1,000,000 population among men and women, respectively. Among men, a larger proportion of the patients with classic KS were of non-Danish origin [odds ratio (OR) = 3.8, 95% confidence interval (CI) = 1.5-9.6]. No excess of foreign born persons was observed among women with KS. Never-married men were at a markedly increased risk for classic KS (OR = 2.8, 95% CI = 1.2-6.7). This risk was, however, restricted to men younger than 60 years (OR = 18.8, 95% CI 3.4-104.8), whereas no increased risk was observed in men age 60 years or older nor was there an increased risk in women. CONCLUSIONS: Classic KS is a rare disease in Denmark. However, men, immigrants and never-married men age 60 years or younger experienced an excess risk. Even though the latter finding might reflect an association with male homosexuality, the observation should be interpreted with caution due to the limited number of observations.

Case-Control Studies

[Improved prenatal diagnostic possibilities for congenital abnormalities and chromosomal disorders. Advantages and disadvantages of screening and diagnostic methods].

Significant progress has taken place in recent years regarding prenatal screening and diagnosis of severe foetal malformations and chromosomal disorders. This review describes blood sample screening in 15-16 week of pregnancy compared with the other prenatal examinations such as amniocentesis and chorionic villus sampling. Serological screening of all pregnant women based on a blood sample taken at 15-16 weeks of pregnancy would lead to identification of about 70% of the screened women having to undergo a conclusive investigation i.e. either a thorough ultrasound examination or an amniocentesis. This is compared with the present Danish prenatal program, where invasive examinations are carried out in about 13% pregnant women without a high detection rate for malformations and chromosome disorders. The Danish National Health Board has recently published new guidelines where the blood test is primarily offered to pregnant women over 34 years of age and not to all pregnant women as in many other countries.

Chromosome Aberrations

Bladder management and urinary tract infections in Danish hospitals, nursing homes, and home care: a national prevalence study.

OBJECTIVE: To establish the prevalence of urinary tract infection in patients undergoing various forms of bladder management. DESIGN: A nationwide descriptive point-prevalence survey with logistic regression analysis of the data relating infection to bladder management. SETTING: Fifteen hospitals, 21 nursing homes, and 13 home care districts throughout Denmark. PATIENTS: Information was collected on 3,665 patients. On the day of the study, 349 patients had indwelling catheters and 1,150 were using external urine drainage systems (condoms or diapers) for bladder management. RESULTS: The prevalence of urinary tract infections in catheterized patients and those using external drainage systems was 13.2% and 8.1%, respectively. The prevalence of hospital-acquired urinary tract infection (4.2%) had not changed from that reported in 1978. The proportion of these infections related to the indwelling catheter, however, had reduced from 66% to 30%. Logistic regression analysis confirmed that, when corrected for the patient-related confounders (female gender, age > 60 years, incontinence, immobility, and stay in hospital for longer than 15 days), condoms (odds ratio [OR], 5.94; 95% confidence interval [CI95], 2.8 to 12.5), indwelling catheters (OR, 3.3; CI95, 2.3 to 4.8), and diapers (OR, 1.5; CI95, 1.1 to 2.1) were significantly (P < .001, P < .001, and P = .008, respectively) related to infection. CONCLUSIONS: Prevalence surveys have revealed that over the period 1978 to 1991, during which efforts have been made to restrict the use of indwelling catheters and to encourage the care of catheterized patients according to guidelines recommended by the Danish National Centre for Hospital Hygiene, the percentage of hospital-acquired urinary tract infections associated with indwelling catheters has been halved. External urine drainage systems, however, have emerged as significant risk factors for urinary tract infection.

Aged

[Occurrence of toxoplasmosis in pregnant women in Denmark. A study of 5.402 pregnant women].

Consecutive serum samples from 5402 women were analyzed for specific IgG and IgM Toxoplasma gondii antibodies by enzyme immunosorbent assay. The prevalence of IgG antibodies was 27.4%. The seroconversion rate was estimated to be 1.16% per year (SE = 0.0017) in all age groups, consistent with an incidence of acute toxoplasmosis in pregnant women of 0.65%. Based on theses figures, the estimated number of congenitally infected cases are discussed. There was no difference in the prevalence of antibodies in women from rural or urban areas, or from different parts of Denmark.

Acute Disease

The role of serum tetranectin, CA 125, and a combined index as tumor markers in women with pelvic tumors.

Serum tetranectin (Se-TN) and CA-125 were measured in 315 patients with a pelvic tumor and 458 healthy females. At a false-positive rate of 0.7% the sensitivity for ovarian cancer stage 1 and 2 was 33% for Se-TN and 76% for both CA 125 and an index based on Se-TN and CA 125 (Index 1). At a false-positive rate of 0.4% the sensitivity was 29% for Se-TN, 62% for CA 125 (35 U/ml), and 76% for Index 1. A negative correlation was found between the Se-TN level and the stage of cancer. The sensitivity for benign tumors was 6% for Se-TN, 17% for CA 125, and 21% for Index 1 at a false-positive rate of 0.4%. In the present study the sensitivity and specificity levels of Se-TN were not sufficiently high to warrant the use of Se-TN as an individual marker for ovarian cancer. The sensitivity rose with the index-based Se-TN and CA 125 without causing a concomitant increase in the rate of false-positive results. None of the markers rose to levels that would allow their use in clinical diagnosis to discriminate between localized cancer and benign tumors.

Adolescent

Bacteremia at a Danish university hospital during a twenty-five-year period (1968-1992).

In the 25-year period 1968-92, 3,317 out of 477,420 patients admitted to Frederiksberg Hospital experienced 3,491 episodes of bacteremia. Enterobacteriaceae dominated as causative agents (57%), following by Gram-positive cocci (31%) and anaerobes (7%). Polymicrobial bacteremia was found in 8% of the episodes. The incidence of Enterobacteriaceae bacteremia culminated in the middle (1978-82) of the period (4.7/1,000 admissions) and decreased during the last decade. Gram-positive bacteremia increased throughout the period (from 1.8 to 2.9; p < 0.001), due mainly to increasing incidences of bacteremia caused by non-hemolytic streptococci, Streptococcus pneumoniae and coagulase-negative staphylococci. Bacteroides fragilis accounted for a rising incidence of anaerobic bacteremia (from 0.3 to 0.7; p < 0.05). Clinical data were available for the 2,599 bacteremic episodes in the 20-year period 1968-87. 59% of these were hospital acquired. Of those, 38% were associated with indwelling catheters, mainly bladder catheters (28%) and i.v. lines (7%). The urinary tract dominated as source of bacteremia (46%), followed by the respiratory (11%) and the gastrointestinal tract (9%). Half of the patients had predisposing underlying diseases, most frequently malignancies (20%) and diabetes mellitus (7%). The mortality rate related to bacteremia decreased from 25% to 11% (p < 0.001). More than half (55%) of the fatal cases related to bacteremia occurred within the first 2 days after the first positive blood culture was obtained. Logistic regression analysis defined 7 variables that independently influenced the outcome related to bacteremia: age, source, culture verification of source, shock, body temperature, leukocyte count and empiric antibiotic treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

The management of urinary catheters: compliance of practice in Danish hospitals, nursing homes and home care to national guidelines.

The compliance of practice to national guidelines on urethral catheter care has been examined. Questionnaires on the practices used with patients under their care were sent to 1350 nursing staff. Replies were received from 1153 individuals, 692 from hospitals, 345 from nursing homes and 116 from home care. While national guidelines stress the importance of maintaining a closed urine drainage system, the results revealed that 25.4% of respondents opened the drainage system to collect samples of urine for analysis, 57.9% to perform bladder washouts and 76% to change urine bags. 26% of respondents reported that they collected urine samples for routine bacteriological surveillance, a procedure considered unnecessary in the guidelines. 83% of staff reported that they washed their hands after emptying urine bags. Staff awareness of written guidelines for various aspects of catheter care ranged from 25-68% in hospitals, 27-45% in nursing homes and 7-17% in home care. A marginal costs analysis was performed to estimate the economic consequences of non-compliance to the national guidelines.

Anti-Bacterial Agents

[Screening of school children for familial hypercholesterolemia].

A total of 3025 families with school children aged six to eight years were offered pilot screening for familial hypercholesterolaemia by measurement of the concentration of apolipoproteins A-1 and B in the children's capillary blood and by analysis of their family histories of early ischaemic heart disease. The concentrations of the apolipoproteins were determined by double rocket immunoelectrophoresis of an eluate of blood spotted on filter paper. Results were available from 2085 children. Because their B:A-1 ratio was above the 97.5 centile and their concentration of B was above the 99th centile, 54 children (2.6%) were selected to have their apolipoprotein concentrations reassessed. The 17 children (0.8%) whose values were persistently above the chosen cut-off points, and all of their available first and second degree relatives, had fasting determinations of serum lipid concentrations carried out. Raised serum concentrations of low density lipoprotein cholesterol and an autosomal dominant pattern of hypercholesterolaemia were found in respectively 12 children and 10 families, suggesting a higher incidence of familial hypercholesterolaemia than the reported 1:500. Further investigations among family members disclosed hypercholesterolaemia in 29 relatives. A family history of early ischaemic heart disease was elicited by questionnaire, and was positive in only five of the 12 school children with hypercholesterolaemia. We conclude that analysis of apolipoproteins from capillary blood spotted on filter paper is suitable for screening for familial hypercholesterolaemia, and that this method is more efficient than screening based on family history.

Apolipoprotein A-I

Epidemiology of pertussis in Denmark: the impact of herd immunity.

BACKGROUND: An evaluation is presented of the Danish pertussis immunization programme, which consists of three injections of plain whole-cell pertussis vaccine given alone at ages 5 weeks, 9 weeks, and 10 months. DATA: The incidence of pertussis in vaccinated and unvaccinated children since the start of vaccination was obtained from the notification system for infectious diseases. Data for vaccination coverage were obtained from the National Social Security. The data for 1980-1986 were supplemented with data from culture-verified cases and hospitalized cases. RESULTS: Compared with other countries using four injections, incidence rates in Denmark are high, especially in pre-school years, leaving infants at a relatively high risk for contracting pertussis from siblings. However, compared with the era before general vaccination, the incidence of pertussis has fallen to one-sixteenth of its former levels. Today, only one in 20 vaccinated, and one in six unvaccinated children develop pertussis before the age of 15 years. This considerable fall, which has also occurred among unvaccinated children, is used to elucidate the importance of herd immunity, which, with the relatively high vaccination coverage in Denmark, was found to play a major role. CONCLUSIONS: The importance of herd immunity is stressed, and it is recommended that a fourth injection of pertussis vaccine is introduced to bring incidence rates down to the very low values found in countries with more intensive vaccination programmes.

Adolescent

Models for prediction of the frequency of toxoplasmosis in pregnancy in situations of changing infection rates.

BACKGROUND: Estimation of the number of women infected during pregnancy with Toxoplasma gondii from seroconversion or seroprevalence data meets with various difficulties. Because of the high risk of transmission of the infection to the fetus such infections are however a major concern in pregnancy-related health planning. METHODS: The expected annual percentage of pregnant women infected with Toxoplasma was calculated using models with varying assumptions with regard to the infection rate, assumed to be independent of age but dependent on calendar time. Three situations were studied: a stable situation, a sudden fall in the infection rate and a gradually declining (slower or faster) infection rate over the lifetime of the pregnant women. RESULTS: With a constant infection rate, a maximum number of affected pregnancies occurs at a yearly infection rate of 4%. In countries with a strongly decreasing annual infection rate, estimates based on data on the relation between age and seropositivity related to only one period of time tend to overestimate the number of affected pregnancies by as much as 60%. CONCLUSIONS: In countries in transition from high to low infection rates, it is likely that the influence of decreasing immunity will, at least temporarily, more than outweigh the influence of the falling infection rates, resulting in a higher number of infected pregnant women. The models used can also describe situations with age-dependent variation in the infection rate, and may well apply to other infectious diseases relevant to pregnancy.

Adult

A new simple and rapid dual assay for AFP and free beta hCG in screening for Down syndrome.

We have evaluated a simple and rapid 2-step dual-label assay (DELFIA) for alphafetoprotein (AFP) and free beta subunit of human gonadotropin (hCG beta) in second-trimester screening for Down syndrome. Based on stored serum samples from 1059 normal control pregnancies and 72 cases of Down syndrome, we have found the mean Multiple of Median (MoM) for AFP and free hCG beta to be 0.70 and 2.31, respectively. This is slightly but not significantly better than the values for the separate assay for AFP (0.76 MoM) and for intact hCG (2.11 MoM). However, the dual assay is much simpler than the separate assays and therefore prospective comparison trials should be carried out.

Chorionic Gonadotropin

A comparison of amniotic fluid alpha-fetoprotein and acetylcholinesterase in the prenatal diagnosis of open neural tube defects and anterior abdominal wall defects.

Amniotic fluid samples received for routine prenatal diagnosis of open neural tube defects were used for a study to compare amniotic fluid acetylcholinesterase (AChE) determination using a monoclonal antibody (4F19) enzyme antigen immunoassay and amniotic fluid alpha-fetoprotein (AFP) measurement as diagnostic tests for open neural tube defects. The study was based on 9964 women with singleton pregnancies and known outcome (including 6 with anencephaly and 18 with open spina bifida) having an amniocentesis at 14-23 weeks of gestation. The AChE immunoassay yielded detection rates for anencephaly of 100 per cent (95 per cent confidence interval (CI) 54.07-100 per cent), for open spina bifida of 100 per cent (95 per cent CI 81.47-100 per cent), for anterior abdominal wall defects of 20 per cent (95 per cent CI 0.51-71.64 per cent), and a false-positive rate of 0.22 per cent (95 per cent CI 0.14-0.34 per cent) excluding anencephaly, open spina bifida, and anterior abdominal wall defects. For similar detection rates the false-positive rate of the AFP test was significantly higher, 0.74 per cent (95 per cent CI 0.58-0.94 per cent). On the basis of these findings, it is recommended that the technically simple AChE immunoassay should be used on all samples; the AFP test should only be used on the 0.5 per cent of the samples with concentrations of AChE activity > or = 8.5 nkat/l for clear samples and blood-stained samples becoming clear after centrifugation, and > or = 25.0 nkat/l for blood-stained samples that are discoloured after centrifugation; an AFP cut-off level of 2.0 MOM is recommended for this policy. Thereby, the detection rates for anencephaly, open spina bifida, and anterior abdominal wall defects would be 100, 100, and 20 per cent, respectively (95 per cent CIs 54.07-100, 81.47-100, and 0.51-71.64 per cent, respectively), and the false-positive rate would be 0.08 per cent (95 per cent CI 0.03-0.16 per cent) (excluding anencephaly, open spina bifida, and anterior abdominal wall defects).

Abdominal Muscles

Management of urinary bladder function in Danish hospitals, nursing homes and home care.

The purpose of this study was to determine the prevalence of the various devices used for bladder function management in Denmark and to assess the scope for the use of alternatives to the indwelling urethral catheter. Data were collected on 1581 hospital patients, 1341 nursing home residents and 743 patients receiving home care. The sample populations were characterized by age, sex and independence in the activities of daily living. The prevalence of indwelling catheters in the three groups of patients was 13.2%, 4.9% and 3.9%, respectively. The equivalent figures for condom drainage systems were 1.5%, 0.8% and 1.2%, and for napkins 10.1%, 52.1% and 34.1%. Comparison of the results from this survey with earlier data indicates that over the period 1980-1991 (during which efforts have been made in Denmark to restrict indwelling bladder catheterization and encourage the use of alternative devices) there has been a reduction in the prevalence of indwelling catheters in hospital medical wards from 13.7% to 6.6%. Examination of the reasons for catheterization revealed that the proportions of patients catheterized because of incontinence were 14% in hospitals, 31% in nursing homes and 33% in home care. There is clearly a need to continue the educational efforts to inform staff of the infection risks and complications associated with indwelling catheters and persuade them of the advantages of the alternative techniques for care of the incontinent patient.

Activities of Daily Living

Use of gloves and handwashing behaviour among health care workers in intensive care units. A multicentre investigation in four hospitals in Denmark and Norway.

Glove use and handwashing frequencies (HW) were observed in intensive care units (ICU) in two university hospitals in Denmark and two in Norway. The study included a total of 1632 patient procedures performed by 325 persons. Handwashing (HW) has become an important part of general barrier precautions. Earlier studies have shown that health care workers (HCW) far too often neglect to wash their hands after patient procedures when handwashing is strongly recommended. Despite earlier claims that increased glove use in hospitals would discourage handwashing, our results showed that HCW washed their hands more often after glove use (57%) than when gloves had not been used (40%). This significant difference in HW frequency was also noted when similar procedures were carried out by HCW with or without gloves. This might be a matter of personal discomfort after wearing gloves, but could also be due to differences in awareness of hygienic aspects of patient care. In the two countries gloves were used on average at 17% of the procedures, but were not used appropriately for dirty procedures. The results of this study indicate that more effective methods for the implementation of appropriate glove use and HW should be emphasized.

Denmark

Prevalence, incidence and geographical distribution of Toxoplasma gondii antibodies in pregnant women in Denmark.

The purpose of this study was to determine the prevalence and incidence of toxoplasmosis in pregnant women in Denmark, and to estimate the incidence of congenital toxoplasmosis. Consecutive serum samples from 5,402 women were analysed for specific IgG and IgM Toxoplasma gondii antibodies by EIA. The prevalence of IgG antibodies was 27.4%. The seroconversion rate was estimated to be 1.16% per year (SE = 0.0017) in all age groups, consistent with an incidence of acute toxoplasmosis in pregnant women of 0.65%. Specific IgM antibodies were present in sera from 29 women. Based on an assumed maternofetal transmission rate of 50%, the incidence of congenital toxoplasmosis was estimated to be 0.33%. Based on these data it is predicted that about 410 pregnant women are infected with T. gondii every year in Denmark, and that about 200 children every year are infected in utero by T. gondii. There was no difference in the prevalence of antibodies in women from rural or urban areas, or from different parts of Denmark.

Adolescent

Simultaneous assay of alpha-fetoprotein and free beta subunit of human chorionic gonadotropin by dual-label time-resolved immunofluorometric assay.

We developed a simple, rapid two-step dual-label assay for the noncompetitive determination of alpha-fetoprotein (AFP) and beta subunit of human chorionic gonadotropin (hCG beta) in serum. Monoclonal antibodies to detect AFP and hCG beta were labeled with europium (Eu) and samarium (Sm), respectively. Highly fluorescent chelates were developed by using the Delfia enhancement principle. The detection limits for AFP and hCG beta were approximately 0.02 kIU/L and approximately 0.2 IU/L, respectively. The within-run precision was < 5% over the whole range of AFP (1-500 kIU/L) and hCG beta (1-200 IU/L) concentrations tested. Cross-reaction of intact hCG was < 0.03%. The AFP concentrations determined with the dual-label assay correlated well with those obtained by Delfia AFP single-label kit. The concentrations of hCG beta were in good agreement with recently published data. Storing the serum samples for 24 h or 1 week at room temperature increased the hCG beta concentration by 4% and 26%, respectively. At 35 degrees C this dissociation of hCG increased 30-40-fold. Repeated freezing and thawing had no effect on the hCG beta concentration.

Antibodies, Monoclonal