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Biomedical subjects

G Johansson

Publications and source records attributed to G Johansson.

At least 271 records · Page 15Linked to original sources
PubMed1987

Neuroaudiological findings in chronic primary fibromyalgia with dysesthesia.

Thirty-six patients (31 females and 5 males) with "chronic primary fibromyalgia" combined with dysesthesia were studied using neuroaudiological tests. Auditory brainstem response (ABR) was pathological in 11 patients (31%). In six instances the I-V interpeak latency (IPL) was prolonged, in two instances the interaural difference of wave V (IT5) was pathological, and in three instances there was a reduction of the amplitude of wave V. A comparison of the I-V IPLs between the female patient group and a matching control group showed that there was a significant prolongation of this parameter in the patient group. The ABR-findings indicate that a brainstem dysfunction might be present in some patients with fibromyalgia. The results of the impedance audiometric tests were generally normal in the patient group.

Acoustic Impedance Tests↗
PubMed1986

Elevation of dental pain threshold induced in man by physical exercise is not reversed by cyproheptadine-mediated suppression of growth hormone release.

The effect of cyproheptadine on growth hormone (GH) secretion and dental pain threshold elevation during physical exercise was studied in healthy human subjects. Different levels of exercise (200-300 W) were produced by a cycle-ergometer. Dental pain thresholds were tested with a constant current pulp tester. In all 6 subjects dental pain thresholds and the heart rate were increased with increasing work load. Cyproheptadine did not have any significant effect on dental pain threshold elevations, although it suppressed the exercise-induced GH release. The results indicate that the exercise-induced dental pain threshold elevation is not based on GH-related stress mechanisms, since cyproheptadine did not reverse the pain threshold elevation.

Adult↗
PubMed1986

Effect of dextran- and poly(ethylene glycol)-bound procion yellow HE-3G on the partition of membranes from calf brain synaptosomes within an aqueous two-phase system.

Membranes obtained by lysis and Yeda-press treatment of synaptosomes (nerve endings) from calf brain cortex have been partitioned within the aqueous phases (and the interface between them) of a Ficoll-dextran-poly(ethylene glycol)-water two-phase system. By introducing the dye Procion yellow HE-3G in the upper phase, bound to poly(ethylene glycol), or in the lower phase, bound to dextran, the partition of the membranes could be strongly affected. The influence on the partition was more pronounced when the dye was bound to dextran. By using a number of two-phase systems in a counter-current distribution process, it was shown that the membrane preparation was inhomogeneous and that the fractions obtained differed in their contents of acetylcholinesterase, succinate dehydrogenase and ATPase. The affinity partitioning effect depended strongly on the concentration of polymer-bound dye. An optimum dye concentration was found when Procion yellow HE-3G was bound to poly(ethylene glycol). When the same dye was bound to dextran, the number of dye molecules per dextran molecule influenced the effectiveness of the extraction.

Acetylcholinesterase↗
PubMed1986

Ruptured abdominal aortic aneurysms: a study of incidence and mortality.

The incidence of ruptured abdominal aortic aneurysms (AAA) during 1980 in the Stockholm county and the clinical fate of the patients were evaluated. Eighty-eight patients with ruptured AAA were found, an incidence of 0.06 per thousand. The overall mortality was 94 per cent. Sixty-four patients reached hospital, twenty-three received a correct diagnosis; thirteen were operated upon and five survived. Autopsy or operation revealed that most ruptures were retroperitoneal (88 per cent) and that only two aneurysms (2 per cent) extended above the renal arteries. It is concluded that the high mortality rate following rupture is more dependent upon failure to operate than on operative mortality.

Age Factors↗
PubMed1986

Selective venous sampling for localization of hyperfunctioning parathyroid glands.

Selective venous sampling with parathyroid hormone assay was used in 46 patients with primary hyperparathyroidism. All patients had previously been operated on in the neck region. In 80 per cent of the patients the method correctly located the position of the hyperfunctioning gland(s). No complications were observed. The method was found to be of great value when evaluating patients with persistent or recurrent hyperparathyroidism.

Adenoma↗
PubMed1986

Impoverished rearing conditions increase stress-induced irritability in mice.

Irritability was tested in mice reared in four environmental conditions: impoverished (IC), impoverished + overstimulated (ICS), enriched (EC), and enriched + overstimulated (ECS) conditions. The test used was a modified "bottle brush" test. Both overstimulations and individual housing increased irritability interacting positively with each other. Individual housing but not overstimulation decreased avoidance behavior in the mice.

Animals↗
PubMed1986

Liquid-liquid extraction of lactate dehydrogenase from muscle using polymer-bound triazine dyes.

An extract from porcine muscle containing soluble enzymes has been partitioned between the two liquid phases of an aqueous, biphasic system consisting of dextran, polyethylene glycol, and water. The influence of polymer-bound triazine dyes (Cibacron blue F3G-A and Procion yellow HE-3G) on the partition of lactate dehydrogenase and total protein was studied. The effects of pH and concentrations of polymers and buffer on this so-called affinity partitioning were also determined. The two-phase systems were used in extraction procedures for purification of lactate dehydrogenase to a specific activity of 456-494 U (7.6-8.4 mukat) per mg protein. The use of these systems for extraction of enzymes in technical scale is discussed.

Animals↗
PubMed1986

Specifically increased solubility of enzymes in polyethyleneglycol solutions using polymer-bound triazine dyes.

The enzymes glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and 3-phosphoglycerate kinase (EC 2.7.2.3), present in an extract of Bakers' yeast, are largely kept in solution by minor amounts of polyethylene glycol-bound triazine dyes (Procion yellow HE-3G and Procion olive MX-3G) even when the solution contains such concentrations of polyethylene glycol (12.5% w/w) which normally precipitate the enzymes. The specific prevention from precipitation can be used for purification of enzyme, preferentially in dealing with crude extracts, which has been demonstrated in this work. A 3.4-fold purification of glucose-6-phosphate dehydrogenase has been achieved with good recovery (93%). Further purification has been possible by combining the recovered (enzyme-containing) supernatant liquid with a solution of dextran which generates an aqueous two-phase system. The lower, dextran-containing phase extracts part of the remaining bulk proteins leaving the target enzyme in the upper phase. The advantages of this method for enzyme purification in large scale are discussed.

Coloring Agents↗
PubMed1986

Superoxide dismutase and catalase reduce infarct size in a porcine myocardial occlusion-reperfusion model.

We investigated if superoxide dismutase and catalase could reduce myocardial infarct size in an open chest occlusion-reperfusion model. Thirty pigs were used for the experiment. The left anterior descending artery was ligated for 60 min followed by a 5 h reperfusion period. After randomisation and blinding the two enzymes or placebo were injected into the left atrium as a bolus immediately before and at the end of the occlusion and as a continuous infusion over the first hour of the reperfusion period. The total dose for each enzyme was 8 mg/kg bw. Tetrazolium staining was used to determine infarct size. The study code was not broken until all calculations and exclusions had been made. Nine animals died from intractable ventricular fibrillation, most commonly during the occlusion. Another three were excluded for technical reasons. We found that superoxide dismutase and catalase reduced infarct size in relation to myocardium at risk from a mean of 89% to 63% (P less than 0.01). Initial plasma half life for the two enzymes after the bolus infusions were calculated to be 30 min.

Animals↗
PubMed1986

Effects of rapid eye movement sleep deprivation on regional brain metabolism as measured by 2-[14C]deoxyglucose autoradiography.

Regional brain metabolic activity of six male Sprague-Dawley rats was investigated with 2-[14C]deoxyglucose autoradiography. Regional brain metabolic activity was determined bilaterally for 60 brain structures, using laser densitometry. After 5 days of uninterrupted rapid eye movement sleep deprivation, increased metabolic activity was found in the lateral habenula, the caudal and middle parts of the limbic system, and in the corpus callosum.

Animals↗
PubMed1986

Increased aggression after rapid eye movement sleep deprivation in Wistar rats is not influenced by reduction of dimensions of enclosure.

Twelve female and twelve male Wistar rats were assigned to home groups, platform-control groups, and rapid eye movement sleep deprivation groups. The deprivation was performed with the cuff-pedestal method. Rats were tested in pairs in a shrinking chamber to increase proximity of the rats and to provoke interaction between them. An increase in boxing behavior was noted in the sleep-deprived groups. The result confirms that deprivation of rapid eye movement sleep increases aggressive behavior in the rat. However, this behavior is not influenced by the area of the testing arena. The sleep-deprived females explored each other more than the controls; the males' behavior did not differ in this respect. The amount of genital exploration decreased with diminishing area of enclosure, whereas boxing was not area dependent.

Aggression↗
PubMed1986

Longterm follow-up of ventilator treated low birthweight infants. II. Neurological and psychological outcome at 6-7 years.

Forty-five of 47 low birthweight infants (less than 2.5 kg b.w.) from a 2 1/2-year period surviving after ventilator treatment in the neonatal period were studied. The children were assessed at the age of 6-7 years by neurological examination and Griffith's test. There were 2 children with diplegia, and one with a descrete hemiplegia. Eleven other children had minor motor disturbances. Fifteen children had short attention span. In the Griffith's test 8 had a general quotient below 3; most often because of low scores in the Locomotor scale and the Performance scales. Eight children had minor motor difficulties and short attention span in combination. These eight children together with the three patients with cerebral palsy, another four patients with low Griffith test and one girl with severe retrolental fibroplasia, and one girl with neurogenic hearing reduction could be at risk for later school difficulties (38%). Finally, one boy was successfully shunted for hydrocephalus. The abnormalities found did not correlate with birthweight or duration of ventilator treatment.

Child↗
PubMed1986

Deoxyglucose-autoradiography of the hypothalamus after food deprivation in the mouse.

[14C] deoxyglucose-autoradiography of mouse brain after food deprivation showed no specific changes in the ratio of autoradiographic optical density of the lateral nucleus of the hypothalamus (LH) versus ventromedial nucleus of the hypothalamus (VMH). The results show that even if there were differences in functional activity between these hypothalamic nuclei during conditions of hunger and satiety, they are not reflected as autoradiographically detectable in relative deoxyglucose uptake.

Acetaminophen↗
PubMed1986

Differential depressant and electrophysiologic cardiotoxicity of local anesthetics: an experimental study with special reference to lidocaine and bupivacaine.

In 15 pigs lidocaine and bupivacaine were injected into the left anterior descending (LAD) coronary artery to investigate the cardiotoxic effects of these drugs. Anesthesia was maintained by a continuous intravenous pentobarbital infusion and ventilation was controlled. Aortic, pulmonary arterial, right atrial, and left ventricular pressures, a standard 12 lead ECG, cardiac output, and great cardiac venous blood flow were recorded. The local anesthetics were administered at body temperature over approximately 10 sec in a random, crossover fashion at the following equipotent anesthetic doses: bupivacaine, 0.25, 0.5, 1, 2, and 4 mg; lidocaine, 1, 2, 4, 8, and 16 mg. The hemodynamic effects were short-lived, peaking about 5 sec after drug infusion. At the highest dose, both drugs decreased left ventricular dP/dT by 28% (P less than 0.001) and aortic blood pressure by 12% (lidocaine) and 8% (bupivacaine) (P less than 0.001 and P less than 0.01). Heart rate, cardiac output, and coronary venous blood flow did not change. Thus, the cardiodepressant ratio between the two drugs was comparable with their local anesthetic the two drugs was comparable with their local anesthetic potency ratio (bupivacaine/lidocaine, 4:1). Seven animals died in ventricular fibrillation within 1 min after 4 mg bupivacaine dose. All animals given 16 mg lidocaine survived. Ventricular fibrillation was preceded by progressive widening of the QRS complexes recorded over the area perfused by the LAD. The ECG changes after 16 mg lidocaine were of the same magnitude as those recorded after 1 mg bupivacaine. In five of the surviving animals 32 and 64 mg lidocaine were injected intracoronarily after termination of the crossover study.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Modification of dental pain and cutaneous thermal sensitivity by physical exercise in man.

The effect of physical exercise on dental pain thresholds, the release of pituitary stress hormones and thermal sensitivity of skin was tested in healthy human subjects. Different levels of exercise (100-300 W) at different pedal frequencies were produced by a cycle ergometer. Thermal limen (the interval between warm and cool thresholds) determined from glabrous hand, hairy forearm and leg was used as a parameter of thermal sensitivity. In all subjects the heart rate and blood pressure were increased with increasing work load. Dental pain thresholds were elevated at high work loads with a concomitant activation of pituitary stress hormone (especially growth hormone) release. Thermal limens at all 3 sites were increased work load, too, independent of the pedal frequency. The increase of thermal limen was most marked in the leg and least in the glabrous hand. The results indicate that physical exercise produces a non-segmental, load-dependent decrease of pain and thermal sensitivity with a concomitant activation of pituitary stress mechanisms. The magnitude of modification varies with skin region. Activation of inhibitory mechanisms at spinal levels via muscle and proprioceptive afferents, in a way suggested by the gate control theory of pain mechanisms, seems to have only a minor, if any, contribution to the present findings, since a higher pedal frequency did not produce a more marked decrease of sensitivity.

Adrenocorticotropic Hormone↗