Superparamagnetic contrast agents for magnetic resonance imaging.
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Animals↗
Biomedical subjects
A Berg
Publications and source records attributed to A Berg.
Dye-ligand centrifugal affinity chromatography.
A fast method for the screening of a large number of immobilized dyes for the purification or binding of proteins called dye-ligand centrifugal affinity chromatography, is described. The ease and speed of this method is demonstrated by screening 65 immobilized dyes for the binding of purified goat IgG. Two immobilized dyes (Drimarene Blue K-R and Drimarene Rubine R/K-5BL) with a high affinity for goat IgG were found to bind specifically the Fc-fragment of the IgG.
Animals↗
[Current aspects of modern ergometry].
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Energy Metabolism↗
[Doping--also a problem in general practice?].
In 1986, the Medical Commission of the IOC defined doping as the use of pharmacological substances belonging to disallowed groups of active substances (stimulants, narcotics, anabolic steroids, beta-blockers, diuretics). With certain restrictions, this applies also to alcohol, local anesthetics and corticosteroids. The use of disallowed methods (blood doping, manipulation of a urine sample) is also forbidden. These days the greatest importance is attached to anabolic steroids (including testosterone), since these substances--discontinued in good time--cannot be detected on the day of competition but still have a promoting effect on performance. Competitive sports prepared the way here for the use of anabolic steroids in general athletics and in particular usually non-olympic sports (such as bodybuilding). Against this background, effects, adverse effects and the risks of anabolic steroid use are discussed. The aim must be to prevent the use of doping, especially in uncontrollable general sports, by promoting proper awareness.
Anabolic Agents↗
[Siliconoma].
We report on a 73-year-old woman who, 12 years after liquid silicone injection for cosmetic purposes, developed siliconoma of her forehead within 9 months. We discuss the clinical and histopathological aspects of this foreign body granuloma.
Aged↗
[Methods of torture and their consequences].
The use of torture has been reported in about 98 countries during the early eighties. Its primary purpose is to paralyse all opposition to the government. It is commonly practiced during the first days immediately after detention, and often in secret prisons. Doctors are frequently involved when torture is planned and carried out. The article gives a brief overview of different methods of torture and the medical consequences for the victim. It also mentions some specific difficulties experienced by Norwegian doctors when treating refugees who have been tortured.
Humans↗
The gene encoding dihydrolipoyl transacetylase from Azotobacter vinelandii. Expression in Escherichia coli and activation and isolation of the protein.
The gene encoding the dihydrolipoyl transacetylase (E2) component from Azotobacter vinelandii has been cloned in Escherichia coli. High expression of the gene was found when the cells were grown for more than 14 h. The E2 produced was partially active, varying 10 and 90% in different experiments. By limited proteolysis of the protein it was shown that the catalytic domain was incorrectly folded, caused by formation of intermolecular or intramolecular S-S bridges. The enzyme was fully activated after unfolding in 2.5 M guanidine hydrochloride containing 2 mM dithiothreitol, followed by refolding by dialysis. Active E2 was isolated in a simple three-step procedure. It possessed a specific activity in the same order as that found after isolation of E2 from purified pyruvate dehydrogenase complex from A. vinelandii. Active E2 comprises about 7% of the total soluble cellular protein in the E. coli clone. By genetic manipulation, deletion mutants of E2 were created, one encoding the lipoyl domain and the N-terminal half of the pyruvate-dehydrogenase (E1)- and lipoamide-dehydrogenase (E3)-binding domain, the other encoding the catalytic domain and the C-terminal half of the E1- and E3-binding domain. In E. coli expression of both mutants was observed.
Acetyltransferases↗
[Treatment of various stages of ethylene glycol poisoning].
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Adult↗
Hormone release from thyrotrophs and lactotrophs during hypo- and hyperglycemia.
To test whether changes in carbohydrate metabolism influence anterior pituitary function, iv TRH tests (25 micrograms TRH) were carried out on three different occasions in 6 normal subjects. On one of these occasions TRH was administered during normoglycemia (blood glucose level 4.5 mmol/l - on the other, during hyperglycemia (10 mmol/l) - and on the third, during hypoglycemia (3 mmol/l). Hypoglycemia reduced the TRH-elicited TSH response significantly (19 +/- 6%), but failed to affect the corresponding PRL response. Hyperglycemia left both the TSH and PRL responses to TRH unaffected. These results imply that thyrotrophs and lactotrophs react differently to changes in carbohydrate metabolism. Thyrotrophs - in contrast to lactotrophs - seem to require a certain minimal glucose delivery to function normally. Glucose excess does not change the reactivity of these pituitary cells significantly.
Adult↗
[Venoglobulins in pediatric surgical resuscitation].
Early postoperative use of iv immunoglobulins after septic surgery in infants is reported. As compared to the randomized control group of patients (n = 20), return of C reactive Protein to normal values first occurred in the group receiving IVI (n = 20) p 0.01.
Bacterial Infections↗
Blood and serum status of water- and fat-soluble vitamins in athletes and non-athletes.
Water- and fat-soluble vitamins have a key function in many metabolic processes and are of special importance for athletic performance. The water-soluble vitamins thiamine, riboflavin, and pyridoxine as well as the fat-soluble vitamins beta-carotene, retinol, and alpha-tocopherol were determined by methods based on high-pressure liquid chromatography (HPLC) in serum or blood of non-athletes and athletes of different sports such as bodybuilders, cyclists, cross-country skiers, marathon runners, and swimmers. The values for the water-soluble vitamin were much higher in athletes, whereas the values for the fat-soluble vitamins were not much different compared to those found in non-athletes.
Adult↗
[The use of flumazenil at a pediatric surgical resuscitation unit].
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Adolescent↗
[Serum and whole blood concentrations of fat and water soluble vitamins in normal persons and athletes].
Water-and fat-soluble vitamins have a key function in many metabolic processes and are of special importance for athletes. The water-soluble vitamins thiamine, riboflavin and pyridoxine and the fat-soluble vitamins beta-carotene, retinol and alpha-tocopherol were determined by High-Pressure-Liquid-Chromatography (HPLC). The mean serum values in non athletes (ng/ml) were for thiamine 9.23 +/- 3.62, riboflavin 6.17 +/- 2.46 and pyridoxine 12.41 +/- 4.59; the blood values for thiamine 20.12 +/- 7.58, riboflavin 13.43 +/- 3.97 and pyridoxine 18.75 +/- 6.66. The mean values of the fat-soluble vitamins were for beta-carotene 3.76 +/- 252 micrograms/l, retinol 598 +/- 141 micrograms/l and alpha-tocopherol 12.6 +/- 2.9 mg/l. The values of athletes (of different sport disciplines) for the water-soluble vitamins were much higher compared to the values found in non-athletes whereas the values for the fat-soluble vitamins were not much different.
Adult↗
Isoelectric focusing of apolipoproteins in immobilized pH gradients: improved determination of apolipoprotein E phenotypes.
A method for isoelectric focusing of apolipoprotein E in an immobilized pH gradient with added carrier ampholytes has been developed. This method is an improvement over conventional isoelectric focusing of apolipoprotein E with respect to resolution, reproducibility, and simplicity. Since monosialo isoforms are resolved from the normally cofocusing asialo isoforms, unique patterns are obtained for all 6 common apolipoprotein E phenotypes. The method can also be applied to the screening of apolipoprotein A and C isoforms. Delipidated very low density lipoproteins (VLDL) have been used as the source of apolipoprotein E and C. Apolipoprotein A isoforms were focused directly from detergent-treated serum. Immunodetection of apolipoprotein E using capillary transfer was found to be compatible with the described method.
Apolipoproteins↗
Influence of probucol administration on lipoprotein cholesterol and apolipoproteins in normolipemic males.
In order to interpret the known lipoprotein changes in probucol-treated patients, serum concentrations of apolipoproteins (A-I, A-II, B, C-II, C-III, E) were measured before, during and after probucol administration (2 X 500 mg p.d.), in 16 healthy males (30.3 +/- 5.6 years old). Cholesterol concentrations were determined in LDL and VLDL fractions as well as in HDL subfractions which were isolated by preparative ultracentrifugation. In addition, apolipoprotein A-I and A-II concentrations were measured in the HDL subfractions. Compared with the baseline values, significant apolipoprotein changes were found in the serum apolipoprotein A-I (151 +/- 18 to 115 +/- 31 mg/dl; P less than 0.001) and C-II levels during administration. The HDL subfraction analysis showed that the decrease of HDL-cholesterol and apolipoprotein A-I (59.9 +/- 23.5 to 34.4 +/- 16.4 mg/dl, P less than 0.001, and 65.7 +/- 49.0 to 37.5 +/- 23.5 mg/dl, P less than 0.05, respectively) was predominantly related to the HDL2b subfraction (d = 1.063-1.100 g/ml).
Adult↗
Effects of fentanyl on baroreceptor reflex control of heart rate in newborn infants.
Baroreceptor reflex control of heart rate was studied in ten neonates and young infants before and after intravenous fentanyl (10 micrograms/kg). All infants were in stable condition while being mechanically ventilated. Mean (+/- SD) corrected gestational age was 40.1 +/- 3.7 weeks, mean weight 3120 +/- 700 g. The pressor response was tested using phenylephrine and the depressor response using nitroglycerin. Changes in heart rate (R-R interval) were plotted against changes in systolic arterial pressure, and the slope of the linear portion of this relationship expresses the baroreflex sensitivity. No significant changes in systolic arterial pressure, heart rate, and blood gas values were observed after fentanyl injection when compared to control values. Mean (+/- SEM) control phenylephrine slope was 8.44 +/- 2.05 msec/mmHg, and mean nitroglycerin slope was 2.54 +/- 0.37 msec/mmHg. Both slopes decreased significantly by 48% and 42%, respectively, after fentanyl injection (P less than 0.02). Mean plasma fentanyl concentrations measured at the end of each test were not statistically different (5.11 +/- 0.65 ng/ml and 4.28 +/- 0.58 ng/ml, respectively). This suggests that the baroreflex control of heart rate is present in term neonates and markedly depressed during fentanyl anesthesia. Changes in blood pressure occurring during fentanyl anesthesia have to be carefully considered, because cardiac output is principally rate-dependent in newborns.
Fentanyl↗
Hypothalamic-pituitary-testicular axis in patients with hyperthyroidism.
To test whether chronic thyroid hormone excess influences the hypothalamic-pituitary-testicular axis, 8 hyperthyroid men were given two identical intravenous GnRH tests. The first test was performed before any treatment had been instituted, the second 6-13 months later, when medical treatment had made the patients euthyroid. Although basal serum luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone (T) levels were of similar magnitudes before and after the medical treatment, LH and FSH responsiveness to gonadotropin-releasing hormone (GnRH), as reflected by the hormone incremental areas (U/l X min), were significantly larger in the thyrotoxic state compared with the euthyroid state (LH incremental areas: 3,999 +/- 665 vs. 2,640 +/- 430, p less than 0.02; FSH incremental areas: 825 +/- 193 vs. 542 +/- 98, p less than 0.05). Furthermore, serum T increased significantly in response to GnRH when the patients were hyperthyroid (T incremental area: 162 +/- 51, p less than 0.02), but failed to do so when they were euthyroid (T incremental area: 92 +/- 53, NS). These results imply that chronic thyroid hormone excess makes the pituitary gonadotrophs 'hypersensitive' to exogenous GnRH. This may in turn explain why human Leydig cells respond more powerful to exogenous GnRH in thyrotoxic patients than in euthyroid subjects.
Blood Glucose↗
Trisomy 21 (Down syndrome): studying nondisjunction and meiotic recombination by using cytogenetic and molecular polymorphisms that span chromosome 21.
By combining molecular and cytogenetic techniques, we demonstrated the feasibility and desirability of a comprehensive approach to analysis of nondisjunction for chromosome 21. We analyzed the parental origin and stage of meiotic errors resulting in trisomy 21 in each of five families by successfully using cytogenetic heteromorphisms and DNA polymorphisms. The 16 DNA fragments used to detect polymorphisms spanned the length of the long arm and detected recombinational events on nondisjoined chromosomes in both maternal meiosis I and maternal meiosis II errors. The meiotic stage at which errors occurred was determined by sandwiching the centromere between cytogenetic heteromorphisms on 21p and an informative haplotype constructed using two polymorphic DNA probes that map to 21q just below the centromere. This study illustrates the necessity of combining cytogenetic polymorphisms on 21p with DNA polymorphisms spanning 21q to determine (1) the source and stage of meiotic errors that lead to trisomy 21 and (2) whether an association exists between nondisjunction and meiotic recombination.
Chromosome Banding↗