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Biomedical subjects

A Thomsen

Publications and source records attributed to A Thomsen.

At least 19 recordsLinked to original sources

[Screening for neuroblastoma in infants aged 6 months. A method of testing].

In a number of cases, neuroblastoma (NB) may be diagnosed by routine screening of the urine for vanillinic-mandelic acid (VMA) and homovanillinic acid (HVA) in symptomfree infants at the age of six months. Early diagnosis of this disease may possibly improve the prognosis. The object of this project was to establish a method of measuring VMA and HVA concentrations in urine collected on filter paper and to assess participation by the parents as regards three different methods of collecting urine with the object of establishing a population screening programme for NB in Denmark. A total of 1,111 infants aged 6-8 months participated in the investigation. The equipment for testing the urine was given in three different was: 1) By the health nurses (County of Arhus), 2) By the general practitioner at the 6-month vaccination (County of Ringkøbing) and 3) By post (County of Viborg). In Arhus, the health nurses delivered the equipment to 96.7% of the age group concerned. Altogether, urine samples were obtained from 673 infants (61%). Participation was greatest in the County of Arhus (66%) and the County of Ringkøbing (62%) and lowest in the County of Viborg (54%). Two infants were found with marginally raised VMA or HVA but these values were found to be normal on repeated examinations. No cases of neuroblastoma were found in the material nor in the screened group in the course of 1 1/2 years after the conclusion of the investigation. In just over 3% of the cases, renewed urine samples had to be sent on account of too little urine on the filter paper. If current population investigations reveal that screening for neuroblastoma can alter the course of the disease in children, the method described here may form the basis for introduction of population investigations in Denmark.

Denmark

Multipoint linkage analysis in X-linked Alport syndrome.

In order to localize the gene for the X-linked form of Alport syndrome (ATS) more precisely, we performed restriction fragment length polymorphism analysis with nine different X-chromosomal DNA markers in 107 members of twelve Danish families segregating for classic ATS or progressive hereditary nephritis without deafness. Two-point linkage analysis confirmed close linkage to the markers DXS17(S21) (zeta max = 4.44 at theta = 0.04), DXS94(pXG-12) (zeta max = 8.07 at theta = 0.04), and DXS101(cX52.5) (zeta max = 6.04 at theta = 0.00), and revealed close linkage to two other markers: DXS88(pG3-1) (zeta max = 6.36 at theta = 0.00) and DXS11(p22-33) (zeta max = 3.45 at theta = 0.00). Multipoint linkage analysis has mapped the gene to the region between the markers DXS17 and DXS94, closely linked to DXS101. By taking into account the consensus map and results from other studies, the most probable order of the loci is: DXYS1(pDP34)-DXS3 (p19-2)-DXS17-(ATS,DXS101)-DXS94-DXS11 -DXS42(p43-15)-DXS51(52A). DXS88 was found to be located between DXS17 and DXS42, but the order in relation to the ATS locus and the other markers used in this study could not be determined.

Female

Comparison of intravenous and topical lidocaine as a suppressant of coughing after bronchoscopy during general anesthesia.

Twenty-four consecutive patients scheduled for fiberbronchoscopy were randomized to receive double-blind either intravenous (1.5 mg/kg) or laryngotracheal (3 mg/kg) lidocaine to evaluate the influence on post-bronchoscopic laryngospasm, pain in the throat and coughing. Plasma lidocaine concentrations were analyzed 5, 15, 30 and 60 min after administration. None of the patients demonstrated laryngospasm or pain in the throat during the first hour after bronchoscopy. Patients receiving topical lidocaine coughed significantly more than patients receiving intravenous lidocaine, with a median number of coughs of 20 compared to 4, during the first hour (P less than 0.01). The plasma lidocaine concentrations were significantly higher after intravenous than after topical administration (P less than 0.001). After intravenous administration the plasma lidocaine concentrations exceeded the accepted level for potential toxicity in five out of 11 patients, but none of the patients developed toxic symptoms and no side-effects were observed.

Administration, Topical

Evaluation of simple tests for detection of HIV antibodies: analysis of interobserver variation in Tanzania.

200 sera were tested for HIV antibodies with different tests in Tanzania. The results were interpreted by 5 different observers with different laboratory experience. There was considerable variation between observers and between testing methods. HIV-Chek was easiest to perform with little interobserver variation, but a few probably false negative readings were seen. Serodia gave many false positives. Western Blots gave more diverging results due to indeterminate sera and lack of training. HIV-Chek seems best when time, facilities, and training are limited and if combined with Serodia false negative results can be excluded.

Blotting, Western

Long-term prognosis of pregnancies in women with intrauterine hematomas.

To evaluate the long-term significance of intrauterine hematomas in patients with threatened abortion, 380 women with a living fetus of more than 8 weeks were studied. On ultrasound, intrauterine hematomas, defined as an echo-poor subchorionic collection, were found in 86 women. Two hundred ninety-four patients without hematomas served as controls. The rate of miscarriage was significantly increased in the study group (22.1 versus 8.2%; P less than .05). Patients discharged from the initial hospitalization without aborting still had a higher abortion risk than controls (16.3 versus 5.6%; P less than .05). Second-trimester debut of symptoms was followed more often by preterm delivery. Thus, patients with intrauterine hematomas continue to be a high-risk group for the remainder of their pregnancies.

Abortion, Spontaneous

Bronchoscopy and nitrous oxide pollution.

The purpose of the investigation was to assess the extent of nitrous oxide pollution during bronchoscopy (rigid ventilation bronchoscope) and further to elucidate the possible reduction in air pollution during local scavenging of leaking gas by a suction catheter placed in the pharynx. The study included 14 adult patients. The leakage of anaesthetic gas was 11.4 +/- 3.2 l min-1 and the median value of the nitrous oxide concentration in the breathing zone of the endoscopist was greater than 300 ppm. Air pollution could not be reduced significantly by scavenging with a suction catheter. The use of inhalation anaesthetics is therefore inadvisable during bronchoscopy in adults unless sufficient anaesthetic scavenging can be established. Other ways of reducing air pollution are discussed and the use of total intravenous anaesthesia or local anaesthesia is advocated.

Air Pollutants, Occupational

Ribosome specificity of archaebacterial elongation factor 2. Studies with hybrid polyphenylalanine synthesis systems.

Polyphenylalanine synthesis with ribosomes and two separated, partially purified elongation factors (EF) was measured in cell-free systems from the archaebacteria Thermoplasma acidophilum and Methanococcus vannielii, in an eukaryotic system from rat liver and an eubacterial one with Escherichia coli ribosomes and factors from Thermus thermophilus. By substitution of heterologous EF-2 or EF-G, respectively, for the homologous factors, ribosome specificity was shown to be restricted to factors from the same kingdom. In contrast, EF-1 from T. thermophilus significantly cooperated with ribosomes from T. acidophilum.

Animals

Renal phosphoenolpyruvate carboxykinase turnover in hypo- and hyperthyroid rat in vivo.

The effect of hypo- and hyperthyroidism on activity, synthesis and degradation of renal cytosolic phosphoenolpyruvate carboxykinase (GTP) (EC 4.1.1.32) was studied in the rat by radioimmunological techniques. In hypo- and euthyroid rats, starvation induced similar alterations in enzyme activities and relative rates of synthesis, whereas in hyperthyroid rats the increase in both was significantly reduced. Substitution of L-thyroxine in hypothyroid rats resulted in a decrease in activity and synthesis within 18 h as observed in hyperthyroid animals. The apparent half-life of the enzyme measured by double-pulse labeling experiments was approx. 13 h in euthyroid animals. The rate of degradation was unaffected by the different thyroid states.

Animals

3,5,3'-Triiodothyronine-induced synthesis of rat liver phosphoenolpyruvate carboxykinase.

Recent studies have indicated that the starvation induced increase in hepatic phosphoenolpyruvate carboxykinase (PEPck; EC 4.1.1.32) is accelerated in hyperthyroid animals, whereas enzyme degradation is unaffected by the thyroid state. Therefore, the present study was undertaken to investigate the possible direct effect of T3 on the synthesis of this important gluconeogenic regulatory enzyme in vivo and in the isolated perfused liver. T3 injection in hypothyroid animals stimulated PEPck synthesis within 6-12 h. The effect, being dose dependent and significant for 0.1 microgram T3/100 g BW, could be demonstrated in animals fasted or fed a carbohydrate-rich diet. Although varying in the basal rate of synthesis, the T3-induced increase in PEPck synthesis was similar in intact, thyroidectomized, adrenalectomized, and hypophysectomized animals. No additive effect with glucocorticoids was observed, suggesting that endogenous glucocorticoids are not necessary for the hormone action. The T3-induced effect on PEPck synthesis was not mediated by alterations in the endogenous cAMP level, as was indicated (1) by the different time course of PEPck induction via (Bu)2cAMP or T3, and 2) by the finding that T3 was effective also in diabetic animals, despite maximally enhanced tissue cAMP levels. In these animals insulin antagonized the T3 action on the enzyme. T3-mediated PEPck synthesis was not prevented by propranolol. Conversely, an additive effect with isoproterenol on enzyme activity was observed. T3 (1 nM) added to the isolated liver of hypothyroid rats perfused with the synthetic fluorocarbon medium supplemented with 10% iodothyronine free serum, stimulated incorporation of labeled leucine into PEPck protein within a 6-h perfusion time. Taken together, our data demonstrate that T3 at a physiological dose stimulates hepatic PEPck synthesis.

Adrenalectomy

Factors influencing seizure duration and number of seizures applied in unilateral electroconvulsive therapy. Anaesthetics and benzodiazepines.

A certain minimum in the duration of seizures appears to be a condition for a satisfactory therapeutic effect in ECT. The aim of the present investigation is to elucidate the importance of some factors which may influence the seizure duration. In a controlled double-blind investigation with crossover, carried out on 19 patients, thiopentone and methohexitone were compared as anaesthetics for unilateral ECT. No differences were found between the anaesthetics regarding duration of seizures, number of treatments with insufficient seizures duration or amount of energy applied. Blood pressure measured after the seizure was slightly higher with thiopentone than with methohexitone and methohexitone as anaesthetic for ECT. In a retrospective investigation concerning seizure duration in unilateral ECT, patients given benzodiazepines during the treatment period were compared with patients who received no such medication. The benzodiazepine group showed shorter seizure duration, more cases with insufficient seizure duration and a need for a greater number of treatments. Benzodiazepines should be administered with caution during ECT, as they can impair the efficacy of treatments and consequently prolong the treatment period.

Adult