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Biomedical subjects

A Aberg

Publications and source records attributed to A Aberg.

At least 19 recordsLinked to original sources
PubMed2002

Childhood malignancy and maternal diabetes or other auto-immune disease during pregnancy.

Among 4380 children born in 1987-1997 of women with a diagnosis of diabetes and alive at the age of one, 10 were registered in the Swedish Cancer Registry before the end of 1998. The odds ratio for having a childhood cancer after maternal diabetes, stratified for year of birth, maternal age, parity, multiple birth, and 500 g birth weight class was 2.25 (95%CI 1.22-4.15). Among 5842 children born during the period 1973-1997 whose mothers had other auto-immune diseases (SLE, rheumatoid arthritis, Crohn, ulcerous colitis, multiple sclerosis or thyroiditis), the number of observed childhood cancers (9) was close to that expected (8.5). Maternal diabetes but not other auto-immune diseases may be a risk factor for childhood cancer.

Autoimmune Diseases↗
PubMed2001

Congenital malformations among infants whose mothers had gestational diabetes or preexisting diabetes.

BACKGROUND: Diabetes type 1 is associated with an increased risk for infant congenital malformations. It is debated whether this is true also at gestational diabetes. AIMS: To study occurrence of congenital malformations in infants whose mothers had preexisting or gestational diabetes. STUDY DESIGN: A register study covering over 1.2 million Swedish births in 1987-1997 based on the Swedish health registries. SUBJECTS: We identified from the Medical Birth Registry 3864 infants born of women with preexisting diabetes and 8688 infants born of women with gestational diabetes. OUTCOMES MEASURES: Congenital malformations identified in the Medical Birth Registry, the Registry of Congenital Malformations, and the Hospital Discharge Registry. The rates of congenital malformations among these infants was compared with the population rates. RESULTS: At preexisting diabetes, the total malformation rate was 9.5% while the rate at gestational diabetes was similar to the population rate, 5.7%. At preexisting diabetes, certain conditions were more common than expected: orofacial clefts, cardiovascular defects, oesophageal/intestinal atresia, hypospadias, limb reduction defects, spine malformations, and polydactyly. For some of these conditions, an excess was found also for infants whose mothers had gestational diabetes. Infants with multiple malformations were in excess at preexisting diabetes but not at gestational diabetes but the specific type of malformations involved were similar in the two diabetes groups. CONCLUSIONS: It is suggested that in the group of gestational diabetes exists a subgroup with an increased risk for a diabetes embryopathy, perhaps due to preexisting but undetected diabetes type 2.

Cleft Lip↗
PubMed2001

Acupuncture for lower back and pelvic pain in late pregnancy: a retrospective report on 167 consecutive cases.

Adverse and analgesic effects of acupuncture during the second and third trimesters of pregnancy were studied retrospectively in an observational study including 167 consecutive patients with lower back pain, pelvic pain, or both. In each patient acupuncture was given on at least two different occasions by three manual stimulations of two or more acupuncture or tender points, mainly LR-3 and LI-4 together with local tender points, at 15-min intervals. Possible adverse and analgesic effects were assessed by the midwife responsible for the acupuncture given in each patient. There were no abortions and no influence on the delivery course of the infants, but transient premature labor was observed during the fourth stimulation carried out in the 15th gestational week in one woman. Other possible adverse effects, like transient dizziness or tiredness, were reported in 35 patients (21%). Analgesia, as assessed by midwives involved, was good or excellent in 72% of patients. Acupuncture seems to be safe and effective for pain relief in lower back pain, pelvic pain, or both during the second and third trimesters of pregnancy. Nevertheless, prospective randomized studies are needed to confirm these findings.

Journal Article↗
PubMed2001

Impaired glucose tolerance associated with adverse pregnancy outcome: a population-based study in southern Sweden.

OBJECTIVE: We conducted a population-based study of maternal and neonatal characteristics and delivery complications in relation to the outcome of a 75-g, 2-hour oral glucose tolerance test at 25 to 30 weeks' gestation. STUDY DESIGN: An oral glucose tolerance test was offered to pregnant women in a geographically defined population. Pregnancy outcome was analyzed according to the test result. RESULTS: Among women delivered at Lund Hospital, we identified 4526 women with an oral glucose tolerance value of <7.8 mmol/L (<140 mg/dL), 131 women with a value of 7.8 to 8.9 mmol/L (140-162 mg/dL), and 116 women with gestational diabetes (> or =9.0 mmol/L [> or =162 mg/dL]). A further 28 cases of gestational diabetes were identified, giving a prevalence of 1.2%. An increased rate of cesarean delivery and infant macrosomia was observed in the group with a glucose tolerance value of 7.8 to 8.9 mmol/L (140-162 mg/dL) and in the gestational diabetes group. Advanced maternal age and high body mass index were risk factors for increased oral glucose tolerance values in 12,657 screened women in the area. CONCLUSION: The study stresses the significance of moderately increased oral glucose tolerance values.

Adolescent↗
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↗
PubMed2001

Association between maternal pre-existing or gestational diabetes and health problems in children.

UNLABELLED: There is general consensus that children of women with pre-existing diabetes mellitus (PDM) have an increased risk of malformations and neurodevelopmental problems. Whether this is also true for children of women with gestational diabetes mellitus (GDM) is a matter of debate. This study investigated inpatient hospital care up to 10 y of age of children born to GDM and PDM women as a rough estimate of child morbidity. Hospital care of children born to 82,684 GDM women, 3,874 PDM women and 1,213,957 controls was compared by linking the Swedish Medical Birth Registry with the Hospital Discharge Registry. Similar comparisons were performed in a local well-controlled group of 326 children born to GDM women in the Lund area. Children of PDM women and to a lesser degree children of GDM women had a statistically significant increase in hospitalizations, evident at least up to 10 y of age. Significantly increased risks of hospitalization were found for neurological/developmental disorders [odds ratio (OR) 2.30 and 1.36 for PDM and GDM, respectively)], malformations (OR 2.05 and 1.23), infections (OR 1.56 and 1.20) and accidents (OR 1.32 and 1.14). CONCLUSION: The high hospitalization rates of these children indicate an increased morbidity, including neurodevelopmental disorders.

Child↗
PubMed2000

Fetal growth is not associated with early onset of severe retinopathy in type 1 diabetes mellitus.

Reduced fetal growth has been suggested as a possible risk factor for diabetic nephropathy. The aim of the present study was to examine whether there could be an association also with rapidly progressing severe retinopathy in younger type 1 diabetic patients. Maternal pregnancy, as well as birth parameters of 27 type 1 diabetic patients with severe retinopathy diagnosis at a median age of 25 years, were studied retrospectively. The control group consisted of 22 type 1 diabetic patients with mild background retinopathy and with similar age, age at onset, and duration of diabetes. Mothers of the subjects with severe retinopathy had a higher body mass index (P = 0.03) but similar age, blood pressure levels, and weight gain during pregnancy as those of the control group. All but four babies, two in each group, were born after 37 completed gestational weeks. There were no differences regarding birth weight or of relative birth weight corrected for gestational length. Head circumference, birth length, and placenta weight were similar. The results indicate that fetal growth is not a factor of major importance for the development of severe retinopathy in younger type 1 diabetic patients.

Adult↗
PubMed2000

Asthma during pregnancy--a population based study.

To study delivery outcome in women with asthma, using Swedish health registers. Women with asthma were identified in two ways: by information in interviews performed by midwives at the pregnant woman's first visit to antenatal care, and by linkage between a medical birth register and a hospital discharge register, identifying women who had been hospitalized for asthma and also had a delivery. Births between 1984 and 1995 were studied. An increased risk for preterm birth and low birth weight was seen, possibly co-varying with disease severity. Also a significant increase in pregnancies of more than 41 weeks duration was noticed. An increase in infant death but not in congenital malformations rate was observed. An association with preeclampsia, gestational diabetes, and infant hypoglycemia was verified. Maternal asthma appears to be a risk factor for preterm and postterm births and increases the risk for some pregnancy complications.

Adult↗
PubMed2000

Caries prevalence and distribution in 3-20-year-olds in Jönköping, Sweden, in 1973, 1978, 1983, and 1993.

Four cross-sectional studies were carried out in 1973, 1978, 1983, and 1993 to collect clinical and radiographic epidemiological data on the dental health status of the inhabitants of Jönköping, Sweden. The aim of the present paper was to use these data to analyze trends in the development of caries among children and adolescents between 1973 and 1993. Approximately 500 randomly selected individuals evenly distributed among the age groups 3, 5, 10, 15, and 20 years participated in each study. The main results show that the numbers of caries-free individuals increased in all age groups. In 1993, the mean number of decayed and filled tooth surfaces in the primary (dfs) and the permanent (DFS) dentition in all age groups was less than half of that found in 1973. Most of this decrease took place during the first 5 years, i.e., between 1973 and 1978. Between 1978 and 1983, only minor changes were observed. There was a further reduction of approximately 30%-50% in dfs/DFS between 1983 and 1993 in 3-, 5-, 10-, and 20-year-olds. The frequency distributions of dfs/DFS for 5- and 15-year-olds revealed an increasing skewness over time: in 1993, a large majority of the children and adolescents had a low or moderate caries severity while only a small group had high scores of dfs/DFS.

Adolescent↗
PubMed1999

Congenital malformations after the use of inhaled budesonide in early pregnancy.

OBJECTIVE: To study possible teratogenic risks with the use of an inhaled glucocorticoid, budesonide, in early pregnancy. METHODS: Using the Swedish Medical Birth Registry, congenital malformations were studied in 2014 infants whose mothers had used inhaled budesonide for asthma in early pregnancy. The presence of congenital malformations was checked further with auxiliary registries. RESULTS: No increase in the general rate of congenital malformations was observed: 3.8% (95% confidence interval [CI] 2.9, 4.6) of the infants had a congenital malformation diagnosed, which is similar to the population rate (3.5%). After exposure to budesonide, four infants were born with orofacial clefts; this also is similar to the expected number (3.3). CONCLUSION: Even though a specific teratogenic effect of use of budesonide in early pregnancy cannot be ruled out, it is unlikely that a clinically significant teratogenic risk exists.

Abnormalities, Drug-Induced↗
PubMed1997

The crystal structure of the signal recognition particle Alu RNA binding heterodimer, SRP9/14.

The mammalian signal recognition particle (SRP) is an 11S cytoplasmic ribonucleoprotein that plays an essential role in protein sorting. SRP recognizes the signal sequence of the nascent polypeptide chain emerging from the ribosome, and targets the ribosome-nascent chain-SRP complex to the rough endoplasmic reticulum. The SRP consists of six polypeptides (SRP9, SRP14, SRP19, SRP54, SRP68 and SRP72) and a single 300 nucleotide RNA molecule. SRP9 and SRP14 proteins form a heterodimer that binds to the Alu domain of SRP RNA which is responsible for translation arrest. We report the first crystal structure of a mammalian SRP protein, that of the mouse SRP9/14 heterodimer, determined at 2.5 A resolution. SRP9 and SRP14 are found to be structurally homologous, containing the same alpha-beta-beta-beta-alpha fold. This we designate the Alu binding module (Alu bm), an additional member of the family of small alpha/beta RNA binding domains. The heterodimer has pseudo 2-fold symmetry and is saddle like, comprising a strongly curved six-stranded amphipathic beta-sheet with the four helices packed on the convex side and the exposed concave surface being lined with positively charged residues.

Amino Acid Sequence↗
PubMed1997

Crystal structure analysis of the activation of histidine by Thermus thermophilus histidyl-tRNA synthetase.

The crystal structure at 2.7 A resolution of histidyl-tRNA synthetase (HisRS) from Thermus thermophilus in complex with its amino acid substrate histidine has been determined. In the crystal asymmetric unit there are two homodimers, each subunit containing 421 amino acid residues. Each monomer of the enzyme consists of three domains: (1) an N-terminal catalytic domain containing a six-stranded antiparallel beta-sheet and the three motifs common to all class II aminoacyl-tRNA synthetases, (2) a 90-residue C-terminal alpha/beta domain which is common to most class IIa synthetases and is probably involved in recognizing the anticodon stem-loop of tRNA(His), and (3) a HisRS-specific alpha-helical domain inserted into the catalytic domain, between motifs II and III. The position of the insertion domain above the catalytic site suggests that it could clamp onto the acceptor stem of the tRNA during aminoacylation. Two HisRS-specific peptides, 259-RGLDYY and 285-GGRYDG, are intimately involved in forming the binding site for the histidine, a molecule of which is found in the active site of each monomer. The structure of HisRS in complex with histidyl adenylate, produced enzymatically in the crystal, has been determined at 3.2 A resolution. This structure shows that the HisRS-specific Arg-259 interacts directly with the alpha-phosphate of the adenylate on the opposite side to the usual conserved motif 2 arginine. Arg-259 thus substitutes for the divalent cation observed in seryl-tRNA synthetase and plays a crucial catalytic role in the mechanism of histidine activation.

Amino Acid Sequence↗
PubMed1997

Pre-eclampsia is a potent risk factor for deterioration of retinopathy during pregnancy in Type 1 diabetic patients.

The aim of the present study was to examine the influence of pregnancy on deterioration of retinopathy in patients with Type 1 diabetes mellitus. Sixty-five pregnant Type 1 diabetic women attending the University Hospital in Lund were studied retrospectively. The degree of retinopathy, and levels of HbA1c and blood pressure 12 months before, during, and 6 months after pregnancy were compared of those of 56 non-pregnant Type 1 diabetic women matched for age and duration of diabetes. For all patients, sight-threatening deterioration of retinopathy did not differ between the pregnancy group (9/65) and the control group (6/56). Over time, pregnant patients had lower HbA1c levels than controls (p < 0.001). Pregnant patients with sight-threatening deterioration of retinopathy had higher HbA1c levels than those without (p = 0.028 and the decrement in HbA1c between the 6-14th and the 20th week of gestation was more pronounced (p = 0.006). In those patients who developed pre-eclampsia during pregnancy, deterioration of retinopathy ocurred more frequently compared to those without pre-eclampsia (4/8 vs 5/65; p = 0.005). In conclusion, sight-threatening deterioration of retinopathy was not more common during pregnancy in IDDM patients than among age- and duration-matched control patients. In pregnant patients, deterioration of retinopathy was associated with the pregestational degree of metabolic control as well as with a rapidly improved glycaemic control acheived during pregnancy. Among those in whom deterioration occurred during pregnancy, pre-eclampsia was a potent risk factor.

Adult↗
PubMed1997

Impaired glucose tolerance during pregnancy is associated with increased fetal mortality in preceding sibs.

OBJECTIVES: To analyze whether women with a diagnosis of gestational diabetes in the current pregnancy had an increased rate of stillbirths or of large for gestational age infants in previous pregnancies without an overtly present/diagnosed gestational diabetes. DESIGN: A case-control analysis with two controls for each case, matched for year of delivery, maternal age (5 year class), and parity. MATERIAL AND METHODS: All women with a diagnosis of gestational diabetes and delivered between 1987 and 1992 were identified from the Swedish Medical Birth Registry. For each woman, the first delivery with that diagnosis was used as proband case (n = 3,958). To each case and control, all previous sibs since 1973 were identified. Comparisons were made between cases and controls but also between sibs of cases and sibs of controls. RESULTS: No significant difference was found in stillbirth rate between cases and controls (OR 1.33, CL 0.64;2.77). The rate of intrauterine deaths was significantly increased among previous sibs of the cases compared with the sibs of the controls: after stratification for year of birth, maternal age and parity an odds ratio of 1.56 (95% CL 1.12;2.19) was found. Infants born of women with gestational diabetes were heavier (mean 145 g, 95% CL 123;168 g). Similar differences were seen between immediately previous sibs of cases and controls (mean 155 g, 95% CL 127;183 g). CONCLUSIONS: The figures indicate that in pregnancies before a delivery with gestational diabetes the perinatal prognosis was significantly poorer than expected which could be due to the presence of undiagnosed and untreated gestational diabetes. The results argue for an improved screening for gestational diabetes during pregnancy.

Abortion, Spontaneous↗
PubMed1996

Crystal structure of reduced protein R2 of ribonucleotide reductase: the structural basis for oxygen activation at a dinuclear iron site.

BACKGROUND: Ribonucleotide reductases (RNRs) catalyze the formation of the deoxyribonucleotides that are essential for DNA synthesis. The R2 subunit of Escherichia coli RNR is a homodimer containing one dinuclear iron centre per monomer. A tyrosyl radical is essential for catalysis, and is formed via a reaction in which the reduced, diferrous form of the iron centre activates dioxygen. To help understand the mechanism of oxygen activation, we examined the structure of the diferrous form of R2. RESULTS: The crystal structures of reduced forms of both wild type R2 and a mutant of R2 (Ser211--> Ala) have been determined at 1.7 A and 2.2 A resolution, respectively. The diferrous iron centre was compared to the previously determined structure of the oxidized, diferric form of R2. In both forms of R2 the iron centre is coordinated by the same carboxylate dominated ligand sphere, but in the reduced form there are clear conformational changes in three of the carboxylate ligands and the bridging mu-oxo group and two water molecules are lost. In the reduced form of R2 the coordination number decreases from six to four for both ferrous ions, explaining their high reactivity towards dioxygen. The structure of the mutant Ser211--> Ala, known to have impaired reduction kinetics, shows a large conformational change in one of the neighbouring helices although the iron coordination is very similar to the wild type protein. CONCLUSIONS: Carboxylate shifts are often important for carboxylate coordinated metal clusters; they allow the metals to achieve different coordination modes in redox reactions. In the case of reduced R2 these carboxylate shifts allow the formation of accessible reaction sites for dioxygen. The Ser211--> Ala mutant displays a conformational change in the helix containing the mutation, explaining its altered reduction kinetics.

Carboxylic Acids↗