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Biomedical subjects

A Ericson

Publications and source records attributed to A Ericson.

At least 73 records · Page 4Linked to original sources
PubMed1983

Erythrocyte nucleotide pattern in two children in a Norwegian family with pyrimidine 5'-nucleotidase deficiency.

In the erythrocytes from two Norwegian children, a brother and a sister, with a hemolytic anemia due to pyrimidine 5'-nucleotidase deficiency, the pyrimidine and purine nucleotides have been investigated using HPLC with a strong anionic exchanger. The standard procedure was complemented with some additional elution systems which made it feasible to separate in the extract and to analyse, in addition to the conventional mono-, di- and triphosphates, UDP-glucose, UDP-N-acetylglucosamine, CDP-choline and CDP-ethanolamine. The two different purine nucleotides (A, G) and the two different pyrimidine nucleotides (U, C) exhibited normal ratios (energy charge ratios) between the conventional nucleotides. This would indicate that the erythrocytes have a sufficient energy production. It is suggested that the partly intravascular hemolysis might be due to disturbed synthesis of phospholipids.

5'-Nucleotidase↗
PubMed1983

A systematic study of nucleotide analysis of human erythrocytes using an anionic exchanger and HPLC.

A two-step procedure for rapid HPLC analysis of nucleotides from human erythrocytes is described. A strong anion exchanger Partisil-10 is used as column material. Elution of monophosphates requires about 12 min and the elution of di- and triphosphates 21 min. The elutions are performed separately and with different injections as such a procedure will save time otherwise used to re-condition the columns. In addition to the three adenylates other nucleotides such as GTP, GDP, IMP and NAD can be recorded as isolated, well-defined peaks, which can be subject to quantitative analysis. The mean value of ATP concentration for 12 healthy individuals was 1.55 +/- 0.05 mmol/l, about 25% higher than generally reported in the literature. Accurate estimates of ADP and AMP concentrations allowed calculation of mean values for the physiologically interesting ratios: adenylate energy charge (0.945 +/- 0.002) and equilibrium constant for adenylate kinase (1.205 +/- 0.053). GDP and GTP are present in concentrations that are about 4% of those for corresponding adenylates. The analysis of nucleotides in human erythrocytes is a useful way of studying erythrocyte preservation and investigating patients with hemolytic disorders.

Adenine Nucleotides↗
PubMed1983

Clusters of malformations in Sweden: a study with central registers.

Clustering of malformations and especially of spina bifida in Sweden was studied using the Register of Malformations and the Medical Birth Records Register. The incentive to this study was provided by the observation of a cluster of malformations, notably spina bifida, and perinatal deaths, locally thought to be related to the use of herbicides in forestry. This cluster was verified but it was shown that a high rate of spina bifida existed in the region before the introduction of herbicides in forestry. Some other clusters of spina bifida were identified and also a number of clusters of other malformations. Case-history studies were performed but revealed no lead to an explanation. Principles in the origin of the clusters and their analysis are discussed.

Abnormalities, Drug-Induced↗
PubMed1983

Lack of correlation between contraceptive pills and Down's syndrome.

A case-control study has been made on the use of oral contraceptives before pregnancy and the birth of an infant with Down's syndrome. Controls were matched for age and parity and selected from the Medical Birth Register. Information on Pill usage was obtained from the Swedish standardized maternity health record which contains dates for when the women stopped using the Pill and for last menstrual period. There was no indication of any relation between the use of oral contraceptives and Down's syndrome.

Adolescent↗
PubMed1983

Erythrocyte pyrimidine 5'-nucleotidase deficiency. Report of 2 new cases, with a review of the literature.

We present 2 Norwegian siblings who we believe to be the first cases of pyrimidine 5'-nucleotidase deficiency diagnosed in the Scandinavian countries. In addition to the features presented by previously published cases, our patients exhibited signs of intravascular haemolysis with haemoglobinuria and increased loss of iron in the urine. The loss of iron has made iron medication necessary from time to time. A kidney biopsy from the oldest patient revealed accumulation of iron in the epithelium of the proximal tubuli. The kidneys were considerably enlarged in both patients, but with normal function tests.

5'-Nucleotidase↗
PubMed1983

Cytosine and uracil nucleotides in erythrocytes from two patients with pyrimidine 5'-nucleotidase deficiency.

The purine and pyrimidine nucleotides in the erythrocytes from two children with 5'-nucleotidase deficiency have been studied using HPLC-technique. The children belonged to the same Norwegian family. In addition to the conventional uracil and cytosine nucleotides relatively high concentrations of UDP-glucose, UDP-N-Ac-glucosamine, CDP-choline and CDP-ethanolamine were found.

5'-Nucleotidase↗
PubMed1983

Assessing a quality control program for erythrocyte preservation and attempts to improve quality of cells after storage at +4 degree C.

About 22 in vitro parameter values were used to evaluate the condition of erythrocytes stored at +4 degrees C in SAGM (1) medium for 28 and 42 d. The parameters were related to such different functions of the erythrocyte, as glycolysis, ion transport, purine metabolism, membrane function and membrane morphology immediately after storage and after subsequent incubation at physiological conditions for 30 min. The evaluation included comparison with posttransfusion viability after 42 d of storage. The investigation gives information in statistical terms about relations between the parameter values and their change with storage time. Total adenylates are superior to ATP in predicting post transfusion viability. There is a good correlation between the in vitro parameters: total adenylates, morphology score and erythrocyte fluidity.

Adenine Nucleotides↗
PubMed1983

Cell shape and total adenylate concentration as important factors for posttransfusion survival of erythrocytes.

Red cells were stored for 42 days in a CPD/SAGM plastic bag system and then rejuvenated with bicarbonate, pyruvate and slow addition of adenosine. The reversibility and the time dependence of metabolic and morphologic changes were compared with autologous, posttransfusion survival. Total adenylates correlated better (r = 0.88) than ATP with viability in vivo ATP was better maintained when the blood was stored under anaerobic than aerobic conditions. A high correlation between morphology and viability was found in rejuvenated cells (r = 0.95). It is suggested that the time needed for reversal of changes is essential for viability.

Adenine Nucleotides↗
PubMed1982

Comparison of infant mortality in the United States and Sweden.

This study summarizes differences between Sweden and the United States regarding certain aspects of infant mortality. Sweden has the lowest infant mortality rate (IMR) and the United States is number 16. Both the neonatal and postneonatal mortality rates of Sweden are considerably lower. Since 1960, the neonatal mortality rate of Sweden was reduced by a greater percentage. The incidence of low birth weight in Sweden is considerably lower. In the United States, no state has an IMR as low as that of Sweden. Nonwhite babies, babies born out of wedlock, and those of teenage or "old" mothers have a higher IMR. The article describes in some detail the organization and network of services in Sweden that may be playing an important role in Sweden's low IMR.

Asphyxia Neonatorum↗
PubMed1982

Gastrointestinal atresia and maternal occupation during pregnancy.

This study originated in observations in cohort studies that women who worked in laboratories during pregnancy may be at increased risk of having an infant with gut atresia. A case-control study has been made of 201 women who had infants with gastrointestinal atresia and 402 women with infants without that malformation but matched for age, parity and time of year for delivery. Maternal occupation during pregnancy was ascertained by interviews of mailed inquiries and only referred to type of occupation; no efforts to obtain detailed information on occupational exposure were made. Occupation of nonresponders was checked using census data. In the case-control study, laboratory work was reported to occur more often among case mothers than among controls, thus verifying the connection. The actual exposure in the laboratory work giving the embryonic damage is not known.

Adolescent↗
PubMed1981

Specimen handling for the assay of adenylates and glycerate 2, 3-bisphosphate in erythrocytes.

ATP, ADP, AMP and glycerate 2, 3-bisphosphate in blood are frequently analyzed in order to evaluate erythrocytes for blood donation and to diagnose hemolytic anemias. In order to find an uncomplicated and safe procedure for the preanalytical treatment of blood a freezing-storing procedure using dry ice was worked out and combined with a later PCA precipitation. The pre-freezing stability of the components was also investigated and found to be best at room temperature.

2,3-Diphosphoglycerate↗
PubMed1981

Delivery outcome for women working in the pulp and paper industry.

A report on unusually many wasted pregnancies among women working at a laboratory in a paper industry gave rise to a cohort study on pregnancy outcome among all women working in the pulp and paper industry in Sweden during 1973--1977. A total of 890 deliveries were identified (899 infants born). The total number of malformed infants or perinatally dead infants was according to expectations. When the material was broken up according to occupation, it was found that, in the group of infants whose mothers worked in laboratories during pregnancy, the rate of malformed infants appeared high. These data, added to previously published data, seem to support the notion that work in laboratories represents a pregnancy hazard.

Adult↗
PubMed1981

Erythrocyte metabolism of purines and purine nucleosides during storage and simulated physiological conditions.

Some results from storage experiments at +4 degrees C with adenine and purine nucleosides in this laboratory are compared with incubation experiments at 37 degrees C with guanosine at pH 7.0 and 7.4 and different levels of inorganic phosphate (iP). At high iP concentration the synthesis of GTP was extremely rapid. Replacement of ATP by and ATP-GTP mixture has metabolic effects on several enzymic steps e.g. phosphofructose kinase and phosphoglycerate kinase explaining the reported beneficial effect on human erythrocytes during preservation. In order to explore the role of erythrocytes in the physiological transport of purines and purine nucleosides in vitro experiments were designed in which the substances were continuously added at the appropriate concentrations by means of a dialysis tubing. Analyses of purines, nucleosides, glucose, lactate and iP in the efferent dialysis solution and the extra- and intracellular volumes reveal the metabolic processes in the erythrocytes if the transport across the dialysis tubing is accounted for. Prior to incubation the erythrocytes were stored with NaF in order to reduce the total adenylate concentration. The rate of synthesis of adenylates was about 0.05 mmol x h(-1) (calculated per litre of erythrocytes) when adenine was supplied as source for the adenine moiety of adenylates but reached a five times higher substance rate when adenosine was supplied at a sufficiently high rate. Adenosine deaminase played an important role also at "sub-physiological" concentrations. The results indicate that the erythrocytes take part in the transport of purines between organs.

Adenine Nucleotides↗
PubMed1981

Purine metabolism of human erythrocytes during storage and physiological conditions.

Some results from storage experiments at +4 degrees C with adenine and purine nucleosides (cf. [1]) are compared with incubation experiments at 37 degrees C with guanosine at pH 7.0 and 7.4 and three different levels of inorganic phosphate (iP). At the lower pH and 20 mmol . l-1 iP the synthesis of GTP was extremely rapid; the intracellular concentration reached 0.5 mmol . l-1 within 25 min constituting 1/3 of the purine nucleoside triphosphate pool. Replacement of ATP by an ATP-GTP mixture has metabolic effects on several enzymic steps, e.g., phosphofructose kinase and phosphoglycerate kinase explaining the reported beneficial effect on human erythrocytes during preservation. In order to explore the role of erythrocytes in the physiological transport of purines and purine nucleosides in vitro experiments were designed in which the substances were continuously added to the appropriate concentrations by means of a dialysis tubing. Prior to incubation the erythrocytes were stored with NaF in order to reduce the total adenylate concentration. The rate of synthesis of adenylates was about 0.05 mmol . h-1 (calculated per litre of erythrocytes) both when adenosine and adenine were supplied as source for the adenine moiety of the adenylates. Analyses of purines, nucleosides, glucose, lactate and iP in the efferent dialysis solution and the extra- and intracellular volumes reveal the metabolic processes in the erythrocytes if the transport across the dialysis tubing is accounted for. The low capacity of the erythrocyte adenylate synthesis indicates that only a minor part of the adenine compounds physiologically exported by the liver could be delivered as intraerythrocytic adenylates.

Adenine↗
PubMed1980

Plasma concentration and renal excretion of adenine and 2,8-dihydroxyadenine after administration of adenine in man.

A new method of high performance liquid chromatography (HPLC) which makes it possible to analyse 2,8-dihydroxyadenine (DOA) in plasma in concentrations exceeding 0.25 mumol/l is described. The method was used to study the renal elimination of DOA. For comparison, the renal handling of adenine was also investigated. The results from an analysis of the experimental data support the assumption that more than one concentration-dependent mechanism exists in the renal tubuli for each of the two purines, adenine and DOA. In general the clearance values are higher for DOA than for adenine and indicate net secretion for both substances.

Adenine↗
PubMed1979

Cigarette smoking as an etiologic factor in cleft lip and palate.

A case-control study has been made on smoking habits in women who, during 1975, gave birth to infants with closure defects of the central nervous system (ASB) or with cleft lip or cleft palate (CLP). For each case, two control subjects with nonmalformed infants were selected and matched for delivery unit, time of delivery, maternal age, and maternal parity. Smoking habits were routinely included in hospital records at first visit to a maternity health clinic during pregnancy. Data were studied for 66 cases of CLP, 66 cases of ASB, and 261 control subjects. Significantly more women who had infants with CLP smoked than did control women, but women with ASB infants showed a normal smoking pattern. Drug use did not explain the findings. It is suggested that maternal smoking is one of many factors of importance in the etiology of cleft lip and cleft palate in humans.

Birth Weight↗