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Biomedical subjects

A Ericson

Publications and source records attributed to A Ericson.

At least 19 recordsLinked to original sources
PubMed2006

Fusion of radiostereometric analysis data into computed tomography space: application to the elbow joint.

Improvement of joint prostheses is dependent upon information concerning the biomechanical properties of the joint. Radiostereometric analysis (RSA) and electromagnetic techniques have been applied in previous cadaver and in vivo studies on the elbow joint to provide valuable information concerning joint motion axes. However, such information is limited to mathematically calculated positions of the axes according to an orthogonal coordinate system and is difficult to relate to individual skeletal anatomy. The aim of this study was to evaluate the in vivo application of a new fusion method to provide three-dimensional (3D) visualization of flexion axes according to bony landmarks. In vivo RSA data of the elbow joint's flexion axes was combined with data obtained by 3D computed tomography (CT). Results were obtained from five healthy subjects after one was excluded due to an instable RSA marker. The median error between imported and transformed RSA marker coordinates and those obtained in the CT volume was 0.22 mm. Median maximal rotation error after transformation of the rigid RSA body to the CT volume was 0.003 degrees . Points of interception with a plane calculated in the RSA orthogonal coordinate system were imported into the CT volume, facilitating the 3D visualization of the flexion axes. This study demonstrates a successful fusion of RSA and CT data, without significant loss of RSA accuracy. The method could be used for relating individual motion axes to a 3D representation of relevant joint anatomy, thus providing important information for clinical applications such as the development of joint prostheses.

Adult↗
PubMed2003

Variation in the position and orientation of the elbow flexion axis.

We analysed the axis of movement in the normal elbow during flexion in vivo using radiostereometric analysis (RSA). The results show an intraindividual variation in the inclination of the axis ranging from 2.1 degrees to 14.3 degrees in the frontal and from 1.6 degrees to 9.8 degrees in the horizontal plane analysed at 30 degrees increments. The inclination of the mean axis of rotation varied within a range of 12.7 degrees in the frontal and 4.6 degrees in the horizontal plane. In both planes, the mean axes were located close to a line joining the centres of the trochlea and capitellum. The intra- and interindividual variations of the axes of flexion of the elbow were greater than previously reported. These factors should be considered in the development of elbow prostheses.

Adult↗
PubMed2002

Neurological sequelae in children born after in-vitro fertilisation: a population-based study.

BACKGROUND: There is an absence of population-based long-term studies on the risk of neurological sequelae in children born after in-vitro fertilisation (IVF). Our aim was to compare the frequency of such problems between IVF-born children and controls. METHODS: We did a population-based retrospective cohort study in which we compared development of neurological problems in 5680 children born after IVF, with 11360 matched controls. For 2060 twins born after IVF, a second set of controls (n=4120), all twins, were selected. We obtained data on neurological problems from the records of the Swedish habilitation centres. FINDINGS: Children born after IVF are more likely to need habilitation services than controls (odds ratio 1.7, 95% CI 1.3-2.2). For singletons, the risk was 1.4 (1.0-2.1). The most common neurological diagnosis was cerebral palsy, for which children born after IVF had an increased risk of 3.7(2.0-6.6), and IVF singletons of 2.8 (1.3-5.8). Suspected developmental delay was increased four-fold (1.9-8.3) in children born after IVF. Twins born after IVF did not differ from control twins with respect to risk of neurological sequelae. Low-birthweight and premature infants were more likely to need habilitation than fullterm babies. Maternal age did not affect risk. INTERPRETATION: Our study suggests that children born after IVF have an increased risk of developing neurological problems, especially cerebral palsy. These risks are largely due to the high frequency of twin pregnancies, low birthweight, and prematurity among babies born after IVF. To limit these risks, we recommend that only one embryo should be transferred during IVF.

Adolescent↗
PubMed2002

Hospital care utilization of infants born after IVF.

BACKGROUND: Infants born after IVF are often twins, and singleton IVF babies have an increased risk for preterm birth. Both conditions are likely to increase morbidity. We examined the frequency and duration of hospitalization required by babies born after IVF, and compared this information with all infants born in Sweden during the same time period. METHODS: We used a nationwide registration of IVF pregnancies from 1984 to 1997 and a nationwide register of all in-patient care up to the end of 1998. We identified 9056 live born infants after IVF treatment and compared them with 1 417 166 non-IVF live born infants. RESULTS: The highest odds ratio (OR approximately 3) was seen for neonatal hospitalization, but an increased OR (1.2-1.3) was noted for children up to 6 years of age. The OR for being hospitalized after IVF was 1.8, but when the analysis was restricted to term infants it was 1.3 and this excess was then explainable by maternal subfertility. Statistically significant increased ORs were seen for hospitalization for cerebral palsy (1.7), epilepsy (1.5), congenital malformation (1.8) or tumour (1.6), but also for asthma (1.4) or any infection (1.4). When information from the Swedish Cancer Registry was used, no excess risk for childhood cancer was found. The average number of days spent in hospital by IVF and non-IVF children was 9.5 and 3.6 respectively. CONCLUSIONS: The increased hospitalization of IVF children is, to a large extent, due to the increased incidence of multiple births. Therefore, the increased costs associated with this may be reduced by the use of single embryo transfers, with the savings in health care costs being offset against the increased number of embryo transfer cycles required to maintain the pregnancy rate.

Birth Rate↗
PubMed2001

Congenital malformations in infants born after IVF: a population-based study.

The presence of congenital malformations in infants born after IVF was studied from a register consisting of practically all infants born in Sweden after IVF, 1982--1997 (n = 9111). A further 64 infants were studied using only medical records. It is a nation-wide study and has a population-based control group (n = 1,690,577) and relevant potential confounders have been taken into account. There was an excess of congenital malformations registered in the Medical Birth Registry (n = 516, odds ratio = 1.47) but this excess disappeared when confounders were taken into consideration: year of birth, maternal age, parity, and period of unwanted childlessness (odds ratio = 0.89). For some specific conditions, an approximately 3-fold excess risk was seen: neural tube defects, alimentary atresia, omphalocele, and hypospadias (after intracytoplasmatic sperm injection). No excess risk for hypospadias was seen after standard IVF. Various explanations for these findings are discussed. It is postulated that the excess risk for alimentary atresia, like the excess risk for monozygotic twinning after IVF, is a direct consequence of the IVF procedure. The excess risk for hypospadias after ICSI may be related to paternal subfertility with a genetic background. The absolute risk for a congenital malformation in association with IVF is small.

Congenital Abnormalities↗
PubMed2001

Use of multivitamins and folic acid in early pregnancy and multiple births in Sweden.

Folic acid is recommended to reduce the risk of neural tube defects and other congenital malformations. Data from the Swedish Medical Birth Registry were used to study frequency of twinning in women who in early pregnancy reported the use of folic acid. Women (n = 2,569) who in early pregnancy reported the use of folic acid had an increased rate of twin deliveries after consideration of maternal age and of length of involuntary childlessness, both variables being significant confounders. The effect of folic acid was seen also in women who did not report involuntary childlessness. A similar but not statistically significant trend was seen after use of multivitamins without simultaneous use of folic acid tablets (n = 1,979). The increased risk seems to be limited to dizygotic twinning (relative risk = 2.13, 95% CI 1.64-2.74). If this association is causal, wide-spread supplementation with folic acid may represent a hazard larger than the postulated beneficial effect on neural tube defects, at least in low-risk areas.

Adult↗
PubMed1999

Deliveries and children born after in-vitro fertilisation in Sweden 1982-95: a retrospective cohort study.

BACKGROUND: In-vitro fertilisation is an effective treatment for infertility, but there is concern about the health of children. We investigated, in a retrospective registry study, malformations, cancers, and deaths in the complete Swedish in-vitro-fertilisation birth cohort compared with the general population. METHODS: We collected data from all in-vitro-fertilisation clinics in Sweden and compared the obstetric outcomes of babies (n=5856) born between 1982 and 1995 with all babies born in the general population (n=1,505,724) during the same period, according to data from the Swedish Medical Birth Registry and the Registry of Congenital Malformations. We investigated the incidence of childhood cancer through the Swedish Cancer Registry. Data were stratified for maternal age, parity, previous subfertility, year of birth, and multiple of pregnancies. FINDINGS: Multiple births occurred in 27% of pregnancies compared with 1% in the control group. In the in-vitro-fertilisation group, more babies were born preterm (<37 weeks) than controls (30.3 vs 6.3%) and more had low birthweights (<2500 g, 27.4 vs 4.6%). The perinatal mortality was 1.9% in the in-vitro fertilisation group and 1.1% in the controls. For in-vitro-fertilisation singletons, the risk ratios, adjusted for year of birth, for very preterm birth (<32 weeks) and very low birthweight (<1500 g) were 3.54 (95% CI 2.90-4.32) and 4.39 (3.62-5.32), respectively. Malformations occurred in 5.4% of all babies in the in-vitro-fertilisation group (1.39 [1.25-1.54]), and the rates of neural-tube defects and oesophageal atresia were higher than those in the controls. There was no increase in childhood cancer in the in-vitro-fertilisation group. INTERPRETATION: A high frequency of multiple births and maternal characteristics were the main factors that led to adverse outcomes, and not the in-vitro-fertilisation technique itself. The clinical practice of in-vitro-fertilisation needs to be changed to lower the rate of multiple pregnancy.

Cohort Studies↗
PubMed1999

[Health care registries a community asset. Centralized registries of health care data can save life and improve quality of life].

The article is a review of how national epidemiological data bases in Sweden can be used for research and statistical purposes. Over 500 major applications from research groups and others are dealt with annually by the National Cancer, Hospital discharge, Medical birth, and Cause-of-death registries, providing essential data for studies which have yielded well over a thousand peer-reviewed scientific papers. In over 40 years' Swedish experience of administering the registration of sensitive patient-specific information on diseases, there has not been a single case of data misuse. It is concluded that the benefits of national epidemiological registries far outweigh the risks and marginal costs of maintaining them.

Computer Security↗
PubMed1999

Delivery outcome after the use of antidepressants in early pregnancy.

OBJECTIVES: To investigate delivery outcome after the use of antidepressants in early pregnancy. METHODS: Using an ongoing prospective recording of drug use in early pregnancy, 969 women were identified who reported the use of antidepressants: 531 used only SSRI (selective serotonin re-uptake inhibitor) drugs (mostly citalopram, 375 exposures), 423 used only other antidepressants, and 15 used both. Outcome was compared with all births in the population. RESULTS: Women using these drugs were older and smoked more than three times as often as other women. There seemed to be an excess of high parity women. The frequency of multiple births was lower than expected, resulting from too few twin births in women who had used SSRI. Gestational duration among singletons was shorter but it did not affect infant survival and was similar after the use of SSRI or non-SSRI antidepressants, perhaps the result of uncompensated for confounding or related to the underlying disease. Infants were somewhat heavier than expected, notably after non-SSRI treatment. No increase was seen in congenital abnormalities, observable in the perinatal period. CONCLUSIONS: Based on this database, the use of antidepressants in early pregnancy does not seem to carry any significant risk for the infant that is detectable during the newborn period.

Adolescent↗
PubMed1998

Very low birthweight boys at the age of 19.

Using linked data from the Swedish Medical Birth Registry and the National Service Enrollment Register, long term follow up (to 18-19 years age) was made of 260 surviving singleton boys whose birthweight was less than 1500 g from a total of 150 229 boys born between 1973-5. These boys were shorter and lighter than boys who weighed more at birth, they had more visual and hearing impairments, were at much higher risk of cerebral palsy and other signs of mental impairment, evident as lower intelligence test scores and shorter schooling. No significant excess of asthma, back problems, or headaches were found.

Adult↗
PubMed1998

Blood transfusion at delivery and risk of subsequent malignant lymphoma in the mother.

BACKGROUND AND OBJECTIVES: Blood transfusion has been shown to be a risk factor for non-Hodgkin's lymphoma (NHL). MATERIALS AND METHODS: In a cohort of 77,928 women with bleeding complications at delivery in the period of 1973-1986, subsequent NHL cases were identified and the number was compared with the number expected from national incidence rates. In a case-control study the proportion of transfused NHL cases was compared with the proportion of transfused controls. RESULTS: The observed number of NHL in the cohort was 18 versus 22.0 expected. Information on transfusion was obtained for 15 of the NHL cases and none (0%) was transfused versus 32 out of 136 controls (23%). CONCLUSIONS: Blood transfusion at delivery is not a risk factor for NHL. The immune tolerance induced by pregnancy may reduce the risk of NHL associated with the transfusion of allogeneic blood cells.

Adult↗
PubMed1995

Preterm birth and low birthweight among children of Swedish and immigrant women between 1978 and 1990.

The aim of the study was to estimate the occurrence of low birthweight (LBW) and preterm birth among immigrant and Swedish women in Sweden. Eligible for analysis were all 1,270,407 singleton births in Sweden between 1978 and 1990 to mothers aged between 15 and 44 years, whose own country of birth was known. The mothers of the children were born in Sweden (88.2%), or had immigrated from Finland (4.4%), other Scandinavian countries (1.2%), Western Europe or North America (1.3%), Eastern Europe (1.8%), the Middle East and North Africa (1.7%), Central and South America (0.6%), Asia and the Pacific Islands (0.6%), or Sub-Saharan Africa (0.2%). Multiple logistic regression was used to model LBW and preterm birth categorical outcomes. Each immigrant group was compared with the Swedish group. Odds ratios (ORs) for LBW were 1.13 (95% CI 1.04, 1.22) for Asia and the Pacific Islands, 1.21 (1.05, 1.38) for Sub-Saharan Africa and 0.89 (0.86-0.93) for Finland. Odds ratios for preterm birth were 1.15 (1.08-1.23) for immigrants from Asia and the Pacific Islands and 1.08 (1.04, 1.13) for immigrants from Eastern Europe. Remarkably small differences were found between immigrant women and native Swedish women.

Adolescent↗
PubMed1994

Pregnancy outcome in Sweden after the Chernobyl accident.

OBJECTIVE: To study pregnancy outcome including development of childhood cancer in areas within Sweden with the highest radioactive fallout after the Chernobyl accident in 1986. METHODS: Various Swedish health registries were used in order to identify all pregnancies and their outcome in Sweden according to the measured radioactive fallout. RESULTS: A reduction in conception rate occurred after the accident, as well as possible increase in induced abortion rate during the fall after the accident. No changes in the rate of spontaneous abortions or congenital malformations occurred in pregnancies exposed at the time of the accident. There was a temporary increase in low birth weight which could well be random. Among infants conceived after the accident, a slight excess of Down syndrome infants was found in the most exposed areas but this observation is based on small numbers. No certain excess of childhood cancer was seen in the most exposed areas, but three infants, in utero at the time of the accident, developed leukemia. CONCLUSIONS: No major effects on pregnancy outcome were seen but the indicated increase in Down syndrome and childhood leukemia--if not random--could be a result of radioactive exposure.

Abortion, Spontaneous↗
PubMed1994

Infant survival in Norway and Sweden 1985-88.

In recent years, considerable attention has been attached to the disquieting fact that infant survival is much lower in Norway than in Sweden. In the present study, comprising all live single births in Norway and Sweden during 1985-88, the observed infant mortality was 1.5 times higher in Norway than in Sweden. The largest difference between Norway and Sweden was found in infants of young mothers with high birth order. Thus for the second births of mothers aged less than 20 years the observed mortality ratio of Norway to Sweden was 1.8. The infant mortality ratio decreased with increasing maternal age for all birth orders, and for the second births of mothers aged 35 years or more the mortality ratio was 1.0. The higher infant mortality in Norway was evident throughout the first year of life, with the highest mortality ratio observed at 6-8 months of life. Adjustment for maternal age, birth order and geographical region did not alter the observed infant mortality ratios. In both countries, the highest risk was found among infants of young mothers. this suggests a need for a more extensive preventive health care system directed at young mothers during their pregnancy and the infancy period.

Adolescent↗
PubMed1993

High adenosine content in human uterine smooth muscle compared with striated skeletal muscle.

We determined the concentrations of adenosine and some of its catabolic products in biopsy specimens from predetermined loci of human myometrium under different functional conditions to compare uterine muscle with rectus abdominis muscle from the same individuals. In order to achieve a good resolution in the separation of nucleosides and purine bases, a preseparation procedure was developed prior to analysis of these compounds on high performance liquid chromatography. Adenosine occurred in a nearly 70-fold higher concentration in smooth uterine muscle in comparison with striated skeletal muscle. Similarly, myometrial inosine and hypoxanthine were 7- and 2.4-times in excess over the rectus muscle, whereas xanthine was scarcely and rather evenly represented in the two types of muscles. The uterine content of adenosine and inosine was distinctly higher in pregnant women compared to non-pregnant ones. A regional difference existed for adenosine, with 3.3 times higher concentration in fundus uteri compared to the isthmic part. A reverse pattern was observed for hypoxanthine and inosine, being 2-3 times more frequent in the isthmic part. The orthophosphate concentration was not stoichiometrically related to the adenosine concentration in a simple way, being 2-3 times lower in uterine muscle compared to the skeletal muscle. A significant correlation existed between uterine contents of AMP and adenosine and similarly, significant inverse correlations were apparent between uterine ATP and ADP contents and energy charge on one hand and adenosine content on the other.

Adenosine↗
PubMed1993

A clinical evaluation of conical crown retained dentures.

In an uncontrolled retrospective recall study of 57 patients treated with conical crown retained dentures, 60 restorations (37 in the maxillae and 23 in the mandible jaw) with a mean wearing time of 30.1 months (range 4 to 76) were evaluated. Of the 248 abutments, eight (3.2%) had been lost. Clinically healthy mucosa was seen in 35 jaws. The marginal fit of the copings was judged to be good. No caries or new restorations were observed in 44 patients. Thirteen patients had 19 surfaces with new restorations and 20 surfaces with caries lesions. Of these 39 surfaces, 38 were located subgingivally.

Adult↗
PubMed1993

Secular trends in the effect of socio-economic factors on birth weight and infant survival in Sweden.

Time trends in the effect of socio-economic factors on low birth weight, stillbirth, perinatal deaths and deaths up to the age of one were studied using a medical birth registry linked to census information from 1975, 1980, and 1985. For each census year, delivery outcome the following year was studied. Two socio-economically different groups of women were studied, defined by occupation/education, cohabitation, and citizenship--one privileged and one under-privileged group. A difference in birth weight distribution was found between the two groups which is only partly explainable by different smoking habits in early pregnancy and did not substantially change during the ten year observation period. In 1976, there was virtually no difference in infant mortality between the two groups. In 1981 and 1986, infant mortality had decreased in both groups but more strongly so in the privileged group, and a difference between the groups therefore appeared.

Adolescent↗