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Biomedical subjects

S Andersson

Publications and source records attributed to S Andersson.

At least 271 records · Page 15Linked to original sources
PubMed1984

Persistent tyrosinemia associated with low activity of tyrosine aminotransferase.

A son of related Turkish parents had grossly elevated serum tyrosine concentration and excreted tyrosine and p-hydroxyphenolic acids into the urine, whereas neither succinylacetone nor succinylacetoacetate could be demonstrated. The tyrosine concentration was normalized by a proper diet. This was not followed strictly at home. During the first 2 years of life, the patient had severe undulating nystagmus that disappeared later. No skin lesions were present and there was only slight corneal clouding of the eyes. At the age of 5, the patient had attained the maturity of a 4-year-old, showing a balanced profile. Specific tyrosine aminotransferase (EC 2.6.1.5) was present in the liver; the Km value for tyrosine was normal. However, the total activity was less than 10% of normal, a situation similar to that observed in fetal human liver. A younger sister of the patient also has tyrosinemia and low hepatic tyrosine aminotransferase activity.

Amino Acid Metabolism, Inborn Errors↗
PubMed1984

Complications after trochanteric fractures. A comparison between Ender and nail-plate osteosynthesis.

Three hundred and forty-one trochanteric femoral fractures operated with intramedullary nailing (Ender) or nail-plate osteosynthesis (McLaughlin) were followed up for 4 months and reoperations were recorded at 18 months. Both methods had an unacceptably high frequency of complications, radiographically in one third and reoperations in one tenth of the total material. The greatest number of operative technical problems was encountered in the Ender group. The 4-month radiographic follow-up showed more complications in unstable than in stable fractures for both methods. In stable fractures, the Ender group had more radiographic complications. There was a slightly better walking capacity at 4 months and fewer reoperations at 18 months in the McLaughlin group.

Bone Nails↗
PubMed1983

25-hydroxylation of C27-steroids and vitamin D3 by a constitutive cytochrome P-450 from rat liver microsomes.

A constitutive cytochrome P-450 catalyzing 25-hydroxylation of C27-steroids and vitamin D3 was purified from rat liver microsomes. The enzyme fraction contained 16 nmol of cytochrome P-450/mg of protein and showed only one protein band with a minimum molecular weight of 51,000 upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified cytochrome P-450 catalyzed 25-hydroxylation of 5 beta-cholestane-3 alpha, 7 alpha-diol, 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha-triol, and 1 alpha-hydroxyvitamin D3 up to 50 times more efficiently, and 25-hydroxylation of vitamin D3 about 150 times more efficiently than the microsomes. The cytochrome P-450 showed no detectable 25-hydroxylase activity towards vitamin D2 and was inactive in cholesterol 7 alpha-hydroxylation as well as in 12 alpha- and 26-hydroxylations of C27-steroids. It catalyzed hydroxylations of testosterone and demethylation of ethylmorphine at the same rates as, or lower rates than, microsomes. The 25-hydroxylation of 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha-triol and vitamin D3 with the purified cytochrome P-450 was not stimulated by addition of phospholipid or cytochrome b5 to the reconstituted system. Emulgen inhibited 25-hydroxylase activity towards both substrates. The possibility that 25-hydroxylation of C27-steroids and vitamin D3 is catalyzed by the same species of cytochrome P-450 is discussed.

Animals↗
PubMed1983

Activity in cortical cells after stimulation of tooth pulp afferents in the cat. Intracellular analysis.

The projection of tooth pulp afferents to cortical cells was studied in intracellular recordings. In a small region of the coronal gyrus, cells in lamina IV were responding at stimulation of contralateral tooth pulp afferents with short latency, steeply rising EPSPs, and one or two action potentials followed by an IPSP. These cells received convergence from skin afferents. In a large cortical area in the coronal, anterior suprasylvian and anterior ectosylvian gyri, tooth pulp stimulation elicited long latency, long lasting EPSPs not succeeded by hyperpolarization mainly in superficial cortical cells. These EPSPs could elicit trains of spikes. A complex type of responses consisted of a short latency EPSP with one or two spikes followed by hyperpolarization which in part was counteracted by a second, long latency EPSP of long duration. Stimulation of low threshold contralateral skin afferents usually gave short latency EPSPs with spikes followed by long lasting hyperpolarization. A common feature of many cells was a high convergence from tooth pulp afferents and bilateral low threshold skin afferents. The response characteristics at tooth pulp stimulation compared to low threshold input are discussed in relation to cortical mechanisms of pain.

Action Potentials↗
PubMed1983

Activity in cortical cells after stimulation of tooth pulp afferents in the cat. Extracellular analysis.

The cortical projection of tooth pulp afferents has been investigated by extracellular recordings in lightly chloralose anaesthetized cats. The results indicate two different projection systems from the tooth pulp afferents terminating on the cortical cells. One system appears to be specific with topographical distribution and activates cells mainly in lamina IV in a restricted region of the coronal gyrus. The cells in this area receive excitation also from restricted cutaneous fields. At stimulation of the tooth pulps with single electrical pulses cells are activated with high discharge probability and with a stable latency. The other system projects mainly to cells in the superficial cortical laminae in a much larger area. These cells receive input from large bilateral cutaneous fields but show less discharge probability and require often temporal summation to discharge at tooth pulp stimulation.

Action Potentials↗
PubMed1983

Incidence and stability of trochanteric femoral fractures.

Sex, age and stability were recorded in 376 cases of trochanteric femoral fractures. In 168 cases the age and sex specific incidence was determined. When comparing our results with those in previous studies from the same region there was no increase that could not be related to age. This is in contrast to other reports from Scandinavia where investigators have found an increase in fracture incidence that could not be explained by the increasing number of old people. We, as others, have found a high proportion of unstable fractures. The unstable fractures did not occur more frequently in the oldest age groups.

Adult↗
PubMed1983

Ibuprofen and compression bandage in the treatment of ankle sprains.

One hundred patients with sprained ankles were randomly allocated to treatment with Ibuprofen 800 mg X 3 daily and placebo and to treatment with two qualities of compression bandaging. Neither Ibuprofen nor high quality bandaging had a significant effect on the swelling, pain or tenderness.

Adult↗
PubMed1983

Visceral pain.

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Animals↗
PubMed1982

Long-lasting cardiovascular depressor response following sciatic stimulation in spontaneously hypertensive rats. Evidence for the involvement of central endorphin and serotonin systems.

A naloxone-reversible long-lasting depressor response induced by a prolonged low frequency stimulation of the sciatic nerve in conscious spontaneously hypertensive rats (SHRs) was reported in a previous paper. In the present study pharmacological tools were used to further investigate the neurotransmitters involved in this phenomenon. Naloxone infusion (20--25 mg/kg/h following a bolus dose of 10 mg/kg i.v.) attenuated significantly the depressor response, while dexamethasone pretreatment had no such effect, suggesting an important role of the brain endorphin system, but not of the pituitary beta-endorphin, in this depressor response. Since the concomitant increase in pain threshold produced by the sciatic stimulation exhibited a different time course of development and naloxone reversibility, it is suggested that the depressor response and the hypalgesic effect produced by the same stimulation are mediated via different types of opiate receptors in the brain. On the other hand, PCPA abolished the post-stimulatory depressor response whereas 5-HTP and zimelidine had additive effects on the sciatic stimulation-induced depressor response, suggesting the involvement of central serotonin systems in the mechanism of the response. The interaction between the central endorphin and the serotonin systems in the mediation of the post-stimulatory depressor response is discussed.

5-Hydroxytryptophan↗
PubMed1982

Long-lasting cardiovascular depression induced by acupuncture-like stimulation of the sciatic nerve in unanaesthetized spontaneously hypertensive rats.

The influence of a prolonged low frequency electrical stimulation of the somatic afferents on cardiovascular and sympathetic nerve activities was investigated in unanaesthetized spontaneously hypertensive rats (SHRs) and Wistar-Kyoto normotensive rats (WKRs). In SHR, an elevation of blood pressure, heart rate and splanchnic nerve outflow was elicited during a 30-min period of sciatic nerve stimulation. Following the cessation of the stimulation, depressor response and bradycardia slowly developed and lasted up to 12 h. Activation of the group III or A-delta afferent fibers was essential for this post-stimulatory response. The progressive depressor response and a parallelled reduction of the splanchnic nerve activity, reached their maxima at about 1 h after the termination of the sciatic stimulation. The magnitude of the post-stimulatory depressor response was correlated with the prestimulatory control blood pressure level. There were also behavioural changes accompanying the depressor response. The cardiovascular and the behavioural depression were immediately reversed by naloxone (10-15 mg/kg, i.v.). The post-stimulatory depressor response was still present after bilateral sino-aortic denervation, but was absent in animals anaesthetized with chloralose and urethane. Emotional stress produced by air-blowing on the animal resulted in pressor response and tachycardia during the period of the stressful stimulation, but there was no depressor response following the termination of air-blowing. These findings indicate a sympathetic and cardiovascular depression induced by a prolonged stimulation of the somatic group III or A-delta afferent fibers; its long duration and naloxone reversibility suggest the involvement of endorphins in the mechanism of this response. The physiological significance of the effects of the prolonged somatic afferent stimulation and its possible relations with acupuncture are discussed.

Acupuncture Therapy↗
PubMed1982

The effect of stimulating somatic afferents on cholera secretion in the rat small intestine.

The effect on rate of cholera secretion in the small bowel of activation of the group III and A delta afferent fibres in the sciatic nerve was studied in rats. Activation of these fibres at 3 Hz for 60 min significantly diminished choleraic secretion from 121 +/- 29 to 25 +/- 9 microliters x min-1 x 100 cm-2 serosal surface (mean +/- SE; n = 9). The effect was apparent after the nerve stimulation. Stimulation of the sciatic nerve had no significant effect on choleraic fluid secretion after interrupting the autonomic nerves to the intestine, nor did it significantly alter net fluid transport in non-choleraic intestine with intact nervous supply. It is proposed that the observations may explain the clinical reports of an effect of acupuncture on cholera secretion.

Afferent Pathways↗
PubMed1982

Anteversion measurements in trochanteric fractures of the femur.

The anteversion of the femur was measured in trochanteric fractures operated upon with nail-plate or Ender osteosynthesis, and the results were compared with a normal material. A significant reduction in anteversion was found in the cases with Ender osteosynthesis as a possible explanation for the outward rotation of the operated limb commonly observed in these patients. No difference in anteversion was found between cases operated upon with conventional Ender technique, i.e. without anteversion of the nails, and those operated upon with a modified technique where the nails had been anteverted if considered appropriate at the operation.

Biomechanical Phenomena↗
PubMed1981

Effect of DLF lesions at different spinal levels on morphine induced analgesia.

The effect of morphine on tail flick latency was tested in 3 groups of rats. It is shown that in normal rats and in rats with a bilateral DLF lesion at Th10 or lower spinal root segments, morphine increased the tail flick latency. After a bilateral DLF lesion at Th9 or higher segments, morphine did not change the tail flick latency.

Animals↗
PubMed1981

Epidural morphine for postoperative pain relief.

Thirty-three patients were randomly assigned to two groups to study the analgesic potency, duration of action and side effects of epidural and intramuscular morphine after hip surgery. Two milligrams of preservative-free morphine chloride in 10 ml of normal saline in the epidural space was compared to 10 mg of intramuscularly administered morphine. There was a more rapid onset of action after intramuscular morphine. However, the quality of pain relief was substantially higher and the duration of action markedly longer after epidural morphine. The total dose required in the epidural group was 3.6 mg and in the intramuscular group 41 mg during the 15-h observation period. The side effects of epidural morphine were few and mild, the most embarrassing being urinary retention (20%). Nausea and/or vomiting was less common after epidural morphine (20% versus 55%). Pruritus or respiratory depression which have been reported previously were not encountered. However, it is recommended that preservative-free solution are used to avoid itching and that the patients are monitored, as respiratory depression may occur long after administration of epidural opiate.

Aged↗