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Biomedical subjects

J Dahl

Publications and source records attributed to J Dahl.

53 records · Page 3Linked to original sources

The "HemoQuant" test: a specific and quantitative determination of heme (hemoglobin) in feces and other materials.

We describe a new, specific, quantitative method for fecal blood, based on conversion of nonfluorescing heme to fluorescing porphyrins, that obviates serious deficiencies inherent in currently used tests. A two-reagent system is used to determine the two hemoglobin-related fractions that are found in feces. The hot citric acid extract includes only the variable fraction of porphyrins that have been preformed from heme in the intestinal tract; this often is the major fraction. Total hemoglobin is indirectly determined by reaction with heated oxalic acid:FeSO4 reagent, which converts the remaining heme to porphyrin without loss of the preformed porphyrins. A three-step purification procedure eliminates interfering materials. Analytical recovery of added hemoglobin is linearly related to concentration over a several-thousand-fold range. The assay is equally applicable to whole blood or to sub-microgram amounts of hemoglobin in the 8-mg (wet weight) fecal sample tested. Quality control by liquid chromatographic and fluorometric analysis documents fluorescence specificity of the heme-derived porphyrins.

Chromatography, High Pressure Liquid↗

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↗

[Therapy and therapeutic results in malignant ovarian tumors (exerience report 1945--1976)].

The study is the result of the medical histories from the Womens Hospital Cottbus from 1945 to 1976 with 387 malignoms of the ovary. The patients material is classified according therapeutic groups. The 5-year survival rates of 345 patients from 1945 to 1971 are 25,9%. The therapy of the ovarian malignoma consists of a combination therapy comprising, according to the stage, operation, radiation therapy and, since 1959 application of cytostatica.

Adult↗

Automated analysis of submicron particles by computer-controlled scanning electron microscopy.

Automated analysis of submicron particles by computer-controlled scanning electron microscopy is generally possible. The minimum diameter of the detectable particles is dependent on the mean atomic number of the particles and the operating parameters of the scanning microscope. The main limitation with regard to particle size is set by the quality of the particle detection system, which generally is the backscatter electron detector. The accuracy of the results of the x-ray analyses is very often strongly affected by specimen damage, omnipresent especially for environmental particles even at low electron energies and probe currents. With the exception for light elements, the detection limit is approximately 1 wt%. Device-related limitations to automated analysis may be specimen drift and an unreliable autofocus function.

Journal Article↗

Effects of a broad-spectrum behavior modification treatment program on children with refractory epileptic seizures.

A group of 18 children with refractory epileptic seizures was divided into three groups--behavior modification treatment, attention control, and control groups--with the purpose of investigating the effects of a learning-based broad-spectrum treatment program superimposed on a regular medical treatment program. The design consisted of a 10-week baseline, 6-week intervention, and 10-week and 1-year follow-ups. A combination of number of seizures and seizure duration--termed "seizure index"--was used as a dependent measure. There was a significant reduction in seizure index only for those children receiving the behavior modification treatment, at both follow-ups. The results indicate that this behavioral treatment program may be of substantial help to children with epilepsy who are resistant to conventional drug therapy.

Adolescent↗

Effects of a contingent relaxation treatment program on adults with refractory epileptic seizures.

A group of eighteen adults with refractory epileptic seizures were given psychological treatment in a two-phase experimental group study. In phase one, the experimental phase, the patients were divided into three groups--contingent relaxation (CR), attention control (ATC) treatment, and a no-treatment (NT) control group--with the purpose of investigating the effects of a learning-based contingent relaxation program compared with the effects of professional attention alone when superimposed on a regular medical treatment program. The design of the experimental phase was comprised of a 10-week baseline, 6-week intervention, and 10-week follow-up. Results of this phase at the end of follow-up showed a significant reduction only for those patients receiving the CR treatment. In the nonexperimental phase, the two control groups also received the CR treatment for a 6-week period, and subsequent seizure frequency measures for all three groups were analyzed after 10-week and 30-week follow-up periods. Results of this phase showed a significant reduction in seizure frequency for all three groups after receiving the CR treatment. Effects of the CR treatment were maintained at a 30-week follow-up. The results indicate that the CR treatment program may be of substantial help to adults whose seizures are resistant to conventional drug therapy.

Adult↗

Effects of a broad-spectrum behavioral medicine treatment program on children with refractory epileptic seizures: an 8-year follow-up.

We present an 8 year follow-up on a group of children with refractory epileptic seizures who participated in the early 1980s in a controlled group study on the effects of a broad-spectrum behavior modification treatment program on children with refractory epileptic seizures. In the original study, 18 children were divided into three groups: behavior modification group, attention control group, and control group. The purpose was to investigate the effects of a learning-based treatment program superimposed on a regular medical treatment program. Also, the effects of professional attention were evaluated. At the 10 week and 1 year follow-ups, only the group receiving the behavior modification intervention had a significantly reduced rate of seizure index. The present study investigates these same children 8 years later using the same methods of investigation for an additional 10 week period. The results indicate that a significant reduction in seizures was obtained only for the behavior modification group at the 8 year follow-up.

Adolescent↗

A new Salmonella surveillance and control programme in Danish pig herds and slaughterhouses.

The Danish Salmonella Surveillance and Control Programme for pigs operates at all stages of the production chain and has been applied nationally since 1995. Due to the program the level of Salmonella in Danish pork has declined from 3.5% in 1993 to 0.7% in the year 2000. Simultaneously, the number of human cases with salmonellosis due to pork has declined from approximately 1,144 in 1993 to 166 in 2000. In year 2001, the programme has been improved at a number of stages. A new classification scheme for the serological surveillance of finisher herds has been developed. The individual test cut-off in the mix-ELISA has been reduced to 20 OD%. Only herds producing more than 200 finishers/year are sampled. Based on the serological result from the last 3 months a new weighted salmonella index is calculated: The Danish Bacon and Meat Council has agreed on a new stricter penalty system. Level 2 and 3 herds get a penalty of 2% and 4% of the value per slaughter carcass, respectively. A new method of Salmonella testing on carcasses has been introduced; 5 carcasses per slaughter day are swabbed at 3 defined areas at 100 cm2 for each sample. This method is more sensitive than the one used previously. Herds infected with multiresistant Salmonella Typhimurium DT104 have to follow special restrictions. These include a requirement for a herd intervention plan, restriction on livestock trade, and a requirement for special slurry handling. Carcasses from DT 104 herds must be heat-treated or decontaminated with hot water.

Abattoirs↗

Bacteriological and serological examination and risk factor analysis of Salmonella occurrence in sow herds, including risk factors for high Salmonella seroprevalence in receiver finishing herds.

A strong association between the seroprevalence in sows and the occurrence of Salmonella Typhimurium among weaners has been shown. As shown several times for finisher herds, the risk-factors, ready mixed pelleted feed and health status also apply to sow herds. Risk factors on the sow level, for high seroprevalence in finishers have been quantified. It has been shown, that isolating Salmonella in weaners is a risk factor for high seroprevalence in finishers. Feed factors; ready-mixed pelleted feed for both sows and finishers, dry feed for sows, have been shown to have a significant effect on high seroprevalence, monitored by meat juice samples at slaughter. The etiological fraction of ready-mixed pelleted feed for sows and for finishers is of the same magnitude, indicating that intervention on the sow level could prove to contribute considerably to the effect of intervention programs.

Animal Feed↗

Effect of separate transport, lairage, and slaughter on occurrence of Salmonella typhimurium on slaughter carcasses.

The study aimed to reduce cross-contamination between finishers from Salmonella-positive and Salmonella-negative herds during transport, lairage, and slaughter, thereby reducing the prevalence of Salmonella Typhimurium on slaughter carcasses. In Phase 1 of the study, pigs from Salmonella-negative herds were kept in lairage for 2-4 hours either in clean pens (intervention group) or pens contaminated with Salmonella-infected faeces (control group). All pigs were slaughtered on the same slaughterline, and carcass swabs 24 hours after slaughter revealed a low degree of cross-contamination in the pens: there was no difference in Salmonella-positive carcasses between intervention (1.7%) and control groups (0.8%). In Phase 2, control pigs from Salmonella-negative herds were mixed with pigs from Salmonella-positive herds during lairage for 2-4 hours, while the intervention group still consisted of pigs from Salmonella-negative herds. All pigs were slaughtered on the same line: first intervention, then control. Carcass swabs taken 24 hours after slaughter failed to show a reduction in Salmonella-positive carcasses in the intervention group (4.5%) compared with the originally Salmonella-negative pigs in the control group (3.6%). In pigs from Salmonella-positive herds the occurrence of Salmonella was substantially higher at 10.4%. When the results were corrected for 6 carcass samples found positive with S. Heidelberg on the same day, which was attributed to a transient hygiene failure, only 2.2% of the carcasses in the intervention group were Salmonella-positive. We conclude that even though cross-contamination occurs in the abattoir pens, its importance on the slaughter line may be greater. However, the final results of this study should be awaited to conclude whether separate slaughter of pigs from Salmonella-positive and Salmonella-negative herds should be recommended.

Abattoirs↗