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Biomedical subjects

K Kristoffersen

Publications and source records attributed to K Kristoffersen.

At least 19 recordsLinked to original sources
PubMed2000

Towards a theory of interrupted feelings.

The purpose of this study is to identify central aspects of feelings in relation to the experience of being a brother or sister of someone who suffers from schizophrenia. The study makes use of a hermeneutical method for the collection of data as well as for the systemizing and interpretation of data. The participants in the study were 16 siblings of persons with diagnosed schizophrenia. In total 80 interviews were done, with an average length of 50 min. A theory of interrupted feelings was developed within the tension between empirical data and preunderstanding. Mixed feelings of grief, hope, anger, guilt and shame are interrupted by four interrelated factors: ambiguous loss, the fluctuating nature of the illness, an inner prohibition of feelings and the tendency of others to invalidate the feelings. The interruption may lead to a lonely and painful experience which is difficult both to process for oneself and to share with others.

Emotions↗
PubMed1999

The influence of folic acid supplement on the outcome of pregnancies in the county of Funen in Denmark. Part I.

OBJECTIVE: To determine whether a supplement of folic acid given preconceptionally or early in pregnancy had any influence on, birth weight, incidence of preterm labour, low birth weight and small for gestational age. Furthermore, the aim was to elucidate, whether the outcome differed following the administration of two different dosages of folic acid, namely 2.5 and 1.0 mg. MATERIAL: All women in the childbearing age living on the island of Funen, Denmark (population 500,000) were offered a supplement of folic acid over a period of 3 years and 3 months. 14,021 women, who gave birth to 13,860 single-born and 325 multiborn children, were registered. A total of 8184 women took part in the double-blind randomized trial: 2310 had a supplement of folic acid without being randomized and 2721 women received no folic acid supplement. No information regarding the use of folic acid was available in 806 pregnancies. Abortions (512) were excluded. RESULTS AND CONCLUSIONS: A supplement 1.0 mg folic acid had the same effect as 2.5 mg. The effects of supplementing the diet with folic acid given preconceptionally or in the first half of pregnancy in an affluent Northern country were a slight increase of birth weight and a decrease in the incidence of preterm labour, infants with low birth weight and small for gestational age. The greatest effect was seen in the groups receiving folic acid preconceptionally.

Birth Weight↗
PubMed1999

The influence of folic acid supplement on the outcome of pregnancies in the county of Funen in Denmark. Part II. Congenital anomalies. A randomised study.

OBJECTIVE: The effect of folic acid supplement on the prevalence of congenital anomalies was studied in a Danish population. MATERIAL AND METHODS: From 1983 to 1986 all Danish women resident in the county of Funen were offered free folic acid when pregnant or planning a pregnancy. Folic acid dose was randomised to 2.5 or 1.0 mg. A randomised control group was not feasible for ethical reasons. Hospitals, midwives and most general practitioners cooperated to procure information on close to all pregnancies and congenital anomalies were recorded. RESULTS AND CONCLUSIONS: In a total of 14,021 pregnancies resulting in child birth 8184 women (58.4%) had folic acid with randomisation. Supplement was started in the randomised group before the last menstrual period in 1359/8184 (16.6%) and in the first 19 weeks of pregnancy in 6825/8184 (83.4%). The prevalence of congenital anomalies was 224 in 8293 children (27.0/1000). No dose-dependent differences were found in either total anomalies or in those specific malformations which have been reported to occur with reduced prevalence with periconceptional folic acid. The result was probably influenced by a start of supplement too late to affect malformation development in many cases and by the high level of both folic acid doses given compared to usual recommendations. Pregnancies without folic acid supplement showed prevalences similar to the supplemented groups.

Congenital Abnormalities↗
PubMed1999

The influence of folic acid supplement on the outcome of pregnancies in the county of Funen in Denmark. Part III. Congenital anomalies. An observational study.

OBJECTIVE: The effect of folic acid supplement on the prevalence of congenital anomalies was studied in a Danish population. MATERIAL AND METHODS: From 1983 to 1986 all Danish women resident in the county of Funen were offered free folic acid when pregnant or planning a pregnancy. Data concerning the starting time of folic acid supplement and congenital anomalies were recorded on close to all pregnancies. Children of folic acid supplemented mothers were subdivided as to start of supplement with dividing lines at week 7 and week 11 calculated from the last menstrual period. Structural malformations were subdivided into an early group with malformation development in the first 7 weeks from the last menstrual period and a late group where malformations develop in weeks 8 to 11. RESULTS: In a total of 14,021 pregnancies 10,494 pregnant women (74.8%) had folic acid supplement. No folic acid was taken by 2721 women (19.4%) and in 806 cases (5.8%) information was lacking. The prevalence of congenital anomalies was 380 in 14,185 children (26.7/1000). Children whose mothers started folic acid supplement before the 7th week of pregnancy showed a significantly lower prevalence of the malformations which develop in the first 7 weeks, when compared to pregnancies with a later start of supplement. The result was interpreted as a clearcut trend.

Congenital Abnormalities↗
PubMed1998

[Air quality and microbiologic contamination in operating theatres].

The present study concerns the air quality and microbiological contamination in two newly built operating theatres; one with laminar air flow (LAF) equipment for cardio-thoracic operations, and one with conventional ventilation for urological operations. Both theatres had an identical number of air exchanges (17/h), identical microclimatic conditions and they employed the same cleaning procedures. In the LAF-ventilated operating theatre bacterial contamination of the air was effectively reduced to less than 10 colony-forming units (CFU)/m3 in all 125 samples (1 m3 per sample) tested. In most samples, 118/125, the bacterial count was less than 5 CFU/m3, despite the presence of ten persons. The conventionally ventilated theatre reached values up to 120 CFU/m3 during the most active period of the day when approximately seven persons were present. The LAF ventilation reduced both the content of particles in the air and contamination by bacteria on the floor. In both theatres cleaning procedures had only a low impact on CFU in the air and on the floor. The use of diathermia markedly increased the level of small particles in the air, and this may influence the air quality in the operating theatres.

Air Conditioning↗
PubMed1997

[Use of natural medicines in women referred to specialists].

The aim was to examine how often women referred to office gynaecologists were using self-medication of "natural medicines". By interview-questionnaires 62 gynaecologists asked 5.664 women about their age, name of used natural medicine and how the user felt it helped her. One thousand six hundred and sixty-four used natural medicine with 91 different names. About 75% percent of the users registered one or more effects, characterized as "good for everything", "enhances their wellbeing" "gives more energy", "relieves hot flushes and sweatings", "relieves rheumatic pain", or "is diuretic". The effects seem to be a universal stimulation of the general condition, effectuated either by vitamins and minerals or by placebo-effect. One third of the users of "melbrosia" registered a good effect on climacteric discomfort. It was not possible by laboratory analyses to find any sex-steroids in melbrosia. Nor was it possible to demonstrate biological oestrogenic effect on animals (mice and rats) of this drug in a trial done by Niels Einer-Jensen et al (personal communication).

Adult↗
PubMed1996

Cimicifuga and Melbrosia lack oestrogenic effects in mice and rats.

OBJECTIVES: The natural medicines, Cimicifuga and Melbrosia, are widely sold. Cimicifuga is an extract of Cimicifuga racemosa (L.), and Melbrosia is a mixture of Gelée Royale, perga-pollen and pollen. Cimicifuga and Melbrosia are used through self-medication to relieve symptoms of hot flushes and other menstrual or menopausal discomfort in many of the Danish women consulting private gynaecologists. A gynaecologist tends to treat these symptoms with oestrogen, so the present experiments were therefore made to investigate whether Cimicifuga and Melbrosia have oestrogenic effects as defined by the classical biological methods: uterine growth in immature mice and vaginal cornification in ovariectomized rats. METHODS: Vehicle, 6, 60 or 600 mg/kg Cimicifuga or 30, 300 or 3000 mg/kg Melbrosia was administered orally for 3 days to groups of 10 immature mice and the uterus weight measured on the fourth day. Similarly, vehicle, 6, 60, 600 mg/kg Cimicifuga or 3, 30, 300 mg/kg Melbrosia was injected subcutaneously in groups of 12 ovariectomized rats for 3 days and vaginal smears investigated for signs of cornified cells. All experiments were repeated once. RESULTS: No signs of an oestrogenic effect connected with the preparations were found in any of the experiments. CONCLUSIONS: It can be concluded that the eventual beneficial effects on menstrual or menopausal discomfort connected with Cimicifuga and Melbrosia self-medication cannot be explained as a traditional oestrogenic effect as measured in biological experiments.

Animals↗
PubMed1996

Staphylococcus aureus carriage and infections among patients in four haemo- and peritoneal-dialysis centres in Denmark. The Danish Study Group of Peritonitis in Dialysis (DASPID).

A three-month prospective surveillance study was undertaken in four dialysis centres to establish the prevalence of Staphylococcus aureus carriage in a Danish population of patients on haemodialysis (HD) or on continuous ambulatory peritoneal dialysis (CAPD). General data such as sex, age, diagnosis, number of months in dialysis, hospital and ward were registered on a precoded form. Standardized nose and four skin swabs (axillae, groins, perineum) were performed on the first day of the survey. After one and two months, nose swabs were collected. Infections were registered and cultures were sent for phage-typing together with the S. aureus strains isolated from the swabs; 59.5% of HD patients and 51.2% of CAPD patients carried S. aureus. Permanent carriage was most frequent (P < 0.00009), primarily in the nose (44.0 and 34.9%, respectively in HD and CAPD). Skin carriage alone was rare (2.4 and 4.7%). Approximately one third (36.6 and 40.7%) of infections were caused by S. aureus. Although diabetics were not significantly more frequent carriers (60.5%) than non-diabetics (55.0%), the incidence of infection was much higher (26.3% vs. 10.3%, P = 0.004). In CAPD, peritonitis and tunnel/exit-site infections predominated (81.4%), often caused by S. aureus (34.8%). More than two thirds of the infections in HD patients were related to intravascular catheterization. The most serious infection was septicaemia, in all cases due to S. aureus. S aureus infections occurred significantly more frequently among carriers (P = 0.005), and more than half the patients were infected by the same or possibly the same strain as they carried in the nose or on skin. Different regimens for the elimination of S. aureus carriage in dialysis patients are discussed. A policy for risk assessment of patients should be developed, and the elimination of S. aureus carriage before dialysis should be encouraged. Controlled trials comparing the cost-effectiveness of recommended regimens to eliminate carriage in HD/CAPD patients are needed. Nose swabs are reliable indicators of carriage in dialysis patients.

Carrier State↗
PubMed1995

Velocity matched spectrum analysis: a new method for suppressing velocity ambiguity in pulsed-wave Doppler.

A new approach to spectrum analysis, which is capable of suppressing velocity ambiguity in pulsed-wave ultrasonic Doppler, is presented. By simultaneous processing of several data samples from a range in depth, the movement of the scatterers along the ultrasonic beam can be tracked from pulse to pulse for each velocity component in the spectrum. In this way the correlation length of the signal component arising from a specific velocity increases when that velocity matches the expected velocity. The resulting velocity/time spectral display shows a more clearly defined spectral envelope of the maximum velocity than with conventional methods based on the discrete Fourier transform of the Doppler signal. This makes it possible to delineate velocity waveforms with peak velocity up to several times the Nyquist limit. Experimental data from human subclavian and aortic arteries are presented, where the new method is compared to conventional spectrum analysis.

Blood Flow Velocity↗
PubMed1995

Predictive analog to digital conversion of Doppler ultrasound signals.

Analog to digital conversion in multigate Doppler ultrasound systems for blood velocity measurements is a technological challenge. The echoes must be digitized at a rate determined by the system bandwidth (typically 2 MHz), and the dynamic range is large (16 bits or more) due to the presence of strong, low-frequency Doppler clutter echoes originating from slowly moving tissue. Off-the-shelf A/D converters do not meet these requirements with the transducer configuration employed by contemporary Doppler systems. Analysis reveals a 5-b reduction in required wordlength for an A/D converter in a predictive feedback loop when the maximum clutter frequency is about 1.5% of the pulse repetition frequency. The prediction error filter is recursive. Alternatively, first- and second-order DPCM (Differential Pulse Code Modulation) yield 4 and 6 b, respectively. With short input segments (from a high-resolution Color Flow Mapper), the results are, in the above order, 4, 4, and 5 b. The results are verified by processing an experimental Doppler signal.

Algorithms↗
PubMed1994

Pseudo-outbreak of pseudomonas aeruginosa in HIV-infected patients undergoing fiberoptic bronchoscopy.

Pseudomonas aeruginosa was isolated from bronchoalveolar lavage fluid from 8 consecutive patients undergoing bronchoscopy at an infectious diseases unit. None of the patients developed signs of respiratory tract infection that could be ascribed to the organism. The source of contamination was the suction channels of 2 fiberoptic bronchoscopes which, due to a lapse in routine procedures, were not cleansed manually prior to disinfection with glutaraldehyde. Although rarely of pathogenetic importance, the possible presence of P. aeruginosa in lavage fluids should never be discounted, as it may indicate faulty disinfection of bronchoscopy equipment and thereby point to a risk of transmission of true respiratory pathogens such as mycobacteria.

Adult↗
PubMed1993

Outbreak of infection in a burns unit due to Pseudomonas aeruginosa originating from contaminated tubing used for irrigation of patients.

Five patients with extensive deep burns developed septicaemia due to Pseudomonas aeruginosa serogroup O-7.8 and phage type 21 or 21/188 shortly after they had been admitted to hospital. Four other burned patients became colonized with the same strain. The source of infection was contaminated tap water used for irrigation of the burns, as part of the first-aid treatment which the patients received when entering the hospital. Contamination was restricted to showers and tubing that were permanently connected to the taps, and the outbreak stopped after they had been disinfected. Tubing and showers used for irrigation of burns should be dismantled and heat-disinfected after each patient and not reconnected to the taps until immediately before the next treatment. Taps used for irrigation of burns should be monitored regularly for the presence of P. aeruginosa and other potentially pathogenic bacteria. Routine typing of P. aeruginosa isolates from burned patients is indicated in order to detect and eliminate hidden sources of infection.

Adult↗
PubMed1989

[Anxiety as an indication for referral for amniocentesis. Follow-up of the course of pregnancy].

A prospective epidemiological investigation was undertaken concerning 2,276 pregnant women referred for amniocentesis during a period of seven years. After exclusion of all of the pregnant women over the age of 35 years and some subgroups, the material consisted of 799 pregnant women under the age of 35 years who were uneasy about the result of pregnancy. These were subdivided and assessed: group A = 329 women with indications for amniocentesis according to the circulars issued by the Danish Ministry of Health and group B = 470 healthy anxious women who desired amniocentesis but without indications. Following genetic counselling, 256 women (B1) still desired amniocentesis while 214 women (B2) now rejected amniocentesis. The courses of the pregnancies in groups A, B1 and B2 were followed-up and assessed. No significant differences were observed between the courses of the pregnancies in group B1 and B2. The tendency demonstrated by this investigation was that anxiety probably did not bear any relation to the outcome of the pregnancy.

Adult↗
PubMed1989

Evaluation of zygosity diagnosis in twin pairs below age seven by means of a mailed questionnaire.

The mothers of a consecutive series of 125 same sexed pairs of twins aged 6 months to 6 1/2 years completed a mailed questionnaire concerning the physical similarity of the twin partners. Zygosity diagnoses were first determined blindly on the basis of the answers given by the mothers, who did not know the result of the blood group test when fulfilling the questionnaire. Next, the results were compared with the zygosity determination based on examination of erythrocyte-, serum- and enzyme-groups. It turned out that a few simple questions distinguished well enough between MZ and DZ pairs, with a frequency of misclassification of 4%, leaving 5% as unclassifiable. It is concluded that twin zygosity can be estimated by a simple questionnaire with sufficient accuracy even in very young twin pairs. This has relevant implications for more extensive twin studies where the use of a wide spectrum of serological characters would imply too high expenses.

Blood Group Antigens↗
PubMed1989

Incidence of spontaneous abortion after amniocentesis: influence of placental localization and past obstetric and gynecologic history.

The influence of the localization of the placenta and some technical problems associated with the performance of amniocentesis (AC) on the incidence of spontaneous abortion (SA) after AC was evaluated in a prospective study comprising all women (2276) referred for AC at the University Hospital in Odense during a 7-year period. Women with predisposing factors for SA were excluded from this analysis, which comprised 1545 women. Of these, 1289 women had an AC and 256 were judged not to need an AC after ultrasonographic examination. The localization of the placenta per se had no influence on the incidence of SA. However, if the placenta was covering the whole anterior wall so that perforation of the placenta could not be avoided, or if more than one insertion was necessary, or there was macroscopic blood contamination in the amniotic fluid, the risk of SA was increased by a factor 4 to 5. The influence of previous obstetric or gynecologic complications on the incidence of SA was also examined. In this analysis the data from women with first trimester hemorrhage in the present pregnancy were included and the study population therefore consisted of 1594 women. Of these, 1318 had an AC, and 276 had ultrasound scanning only. Patients with one or more previous pregnancies with fetal loss had a significantly greater risk of SA after AC than patients with no previous pregnancies or successfully completed pregnancies. Two subgroups with special problems, namely, women with previous complaint of infertility of at least 2 years' duration and women with first trimester bleeding, also had an increased risk of SA.(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Spontaneous↗