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Biomedical subjects

L Bergström

Publications and source records attributed to L Bergström.

At least 91 records · Page 5Linked to original sources
PubMed1984

Post-mortem analyses of neuropeptides in brains from sudden infant death victims.

The causative factors underlying SIDS are still unknown, but in recent years much interest has been focused on the central ventilatory control system. In this study, peptides which are known to affect respiration were examined in brains from SIDS victims and controls. The levels of Met-enkephalin and substance P were measured in cortex, medulla oblongata, pons and hypothalamus. Substance P1-7, substance P C-terminal fragments, Met-enkephalin-Lys6 and neuropeptide Y (NPY) were estimated in medulla oblongata. The substance P levels in the medulla oblongata from the SIDS victims were significantly elevated compared with the controls. No change, however, was observed in the Met-enkephalin levels, but a tendency to higher levels in the youngest infants was noticed. As substance P and enkephalins have opposite effects on respiration, their relative concentrations were calculated in each individual sample. The ratio was significantly higher in the medulla oblongata from the SIDS victims. The levels of NPY, substance P1-7, C-terminal fragments of substance P and Met-enkephalin-Lys6 were similar in both groups. A significant correlation between the NPY levels and age was observed, however.

Age Factors↗
PubMed1984

Substance P levels in various regions of the rat central nervous system after acute and chronic morphine treatment.

Substance P levels were measured in various CNS regions from rats treated acutely and chronically with morphine. There was no observable effect in the group treated with an acute dose of morphine (10 mg/kg) and sacrificed after 2 h. After 35 days chronic treatment with increasing doses of the drug, the rats were divided into three groups and sacrificed 2 h, 24 h and 7 days after the last injection. The substance P level was increased in the corpus striatum 2 h and 24 h and in the medulla oblongata and dorsal part of the spinal cord 2 h after withdrawal. Seven days after the last injection the levels had returned to normal in these areas. No effects were observed in the cerebral cortex, the hypothalamus or the ventral spinal cord at any time of measurement. Earlier studies have demonstrated that morphine inhibits release of substance P. The observed increase in tissue levels after long-term treatment is therefore interpreted as an accumulation of substance P in the neurons.

Animals↗
PubMed1984

Neurotoxic and other side effects of high-dose interferon in amyotrophic lateral sclerosis.

6 patients with amyotrophic lateral sclerosis were treated with intravenous infusion of 100-200 million IU per day of human leukocyte interferon. Side effects of treatment included fever, chills, malaise, nausea, marked leukopenia, mild anemia, and thrombocytopenia. Tiredness, confusion, papilledema, and overall signs of acute encephalitis were observed. Tendon reflexes and muscle force decreased. EEG activity was slowed, and evoked potentials showed significant slowing of conduction times. Neuropsychological tests revealed congitive dysfunction. The syndrome of inappropriate antidiuretic hormone secretion developed in all patients. All side effects were reversible with cessation of interferon treatment.

Adult↗
PubMed1983

An ion exchange chromatography and radioimmunoassay procedure for measuring opioid peptides and substance P.

The measurements of peptides of the enkephalin, dynorphin and substance P systems is complicated by the number of possible precursor fragments and degradation products that might cross-react with the antisera. By using an ion-exchanger step before radioimmunoassay we can reduce the possibility that observed peptide levels are due to precursors or metabolites. The ion-exchanger method runs with good recovery and its main advantage is that many samples can be run in parallel. The recovery from the ion-exchanger was similar using two different homogenizing media, whereas the measured endogenous levels of [Met] and [Leu]enkephalin were 3-4 fold higher with 1M acetic acid than when a 1:1 MeOH/HCl mixture was used for tissue extraction.

Acetates↗
PubMed1983

Brainstem auditory-evoked potentials in progressive myoclonus epilepsy without Lafora bodies.

We studied brainstem auditory-evoked potentials of 11 patients suffering from the Finnish type of progressive myoclonus epilepsy (without Lafora bodies). All patients were ambulatory and had regular antiepileptic medication. The responses of 5 patients were interpreted as totally normal. In 6 cases there were slight deformations of the wave forms or of the amplitudes of the responses. The central conduction time of all patients was within the +/- 2 S.D. limits of the normal values. Postauricular muscular responses were not more prominent in patients than in controls. The results indicate that there is not any significant dysfunction in the cholinergic auditory pathways of the brainstem of these patients.

Adolescent↗
PubMed1979

Enkephalin levels decrease in rat striatum during morphine abstinence.

Male Sprague-Dawley rats were treated with morphine for 11 days. Saline-injected animals served as controls. The striatal enkephalin levels were measured with a radioimmunoassay 2, 24 and 48 h after withdrawal. There was no change 2 h after the last morphine injection, but a marked reduction after 24 h and a slight decrease after 48 h. No decrease in enkephalin levels was found 12 and 24 h after a single dose of 20 mg/kg morphine.

Animals↗
PubMed1979

The prognosis of near-drowned children.

Thirty children were treated for near-drowning in the Children's Hospital, University of Helsinki during 1971--1976. The patients were divided into 3 groups according to the prognosis: group I included 13 children (43%) with a favourable prognosis, group II four children (13%) with a less favourable prognosis who developed severe sequelae, and group III 13 children with poor prognosis and in whom the subsequent outcome proved fatal. The surviving children underwent neurological, neurophysiological and psychological examination 6--58 months after the accident. The children in group I had slight neurological or psychological signs, some children presented a lowered intellectual functioning level. The children in group II were tetraplegic, unable to speak and had convulsions. The following factors were important in affecting prognosis: the longer the immersion time, the worse the prognosis. However, prognosis could still be favourable with an immersion-time of 11-20 min. Prognosis was bad if the first pH value was less than 7.00. The arterial oxygen pressure values measured during the treatment did not correlate with the prognosis but a low rectal temperature on admission was usually associated with a bad prognosis. The degree of EEG-disturbance had a prognostic value. However, the follow-up recording correlated better with the prognosis than the recordings during the first 24 hours, after which worsening of the EEG sometimes showed a progressive brain lesion.

Adolescent↗
PubMed1977

Cerebrospinal fluid sorbitol and myoinositol in diabetic polyneuropathy.

Changes in cerebrospinal fluid (CSF) concentrations of sorbitol and myoinositol in 21 patients with diabetic polyneuropathy were studied with gas-liquid chromatography. The sorbitol concentration was significantly increased in diabetic patients with elevated plasma glucose. Myoinositol concentration was significantly decreased in patients with polyneuropathy compared with the controls. Both alterations in polyol concentrations of the CSF were present already two months from onset of symptoms of diabetes. Patients with peripheral polyneuropathy receiving oral hypoglycemic drugs did not have elevated plasma glucose and CSF sorbitol levels, but showed significantly decreased CSF myoinositol concentrations compared with the controls. These observations suggest that myoinositol concentration may be decreased in the central nervous system in adult onset mild diabetes with normal plasma glucose and that the decrease in the myoinositol in CSF possibly is connected with the development of neuropathy.

Adult↗
PubMed1975

The transient global amnesia syndrome. An analysis of 35 cases.

On basis of 35 patients who have suffered from transient global amnesia the pathophysiological mechanisms of this syndrome are discussed. Our impression is that the primary cause of this syndrome is a transient ischemia of the hippocampus, an opinion common with most earlier authors. The possibility of a unilateral hippocampal disturbance resulting in transient global amnesia is discussed. We are inclined to regard the local hippocampal ischemia as arising from insufficiency of the anterior chorioidal artery and thus as a sequel of internal carotid insufficiency, which has earlier been proved to result from various rotatory, flexion, and extension movements of the neck.

Adult↗