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Biomedical subjects

F Gjerris

Publications and source records attributed to F Gjerris.

At least 109 records · Page 6Linked to original sources
PubMed1984

Impermeability of the blood-cerebrospinal fluid barrier to 1-deamino-8-D-arginine-vasopressin (DDAVP) in patients with acquired, communicating hydrocephalus.

The passage of the vasopressin analogue, 1-deamino-8-D-arginine-vasopressin (DDAVP) into the cerebrospinal fluid (CSF) following intravenous (i.v.) administration was studied in human subjects. After i.v. injection of DDAVP, resulting in plasma levels exceeding normal plasma concentrations of vasopressin (AVP) by 100-fold, serial blood and ventricular CSF specimens were sampled during 2 h. Plasma and CSF were analysed by radioimmunoassay using two different AVP antisera: one specific against natural AVP and another cross-reacting 100% with DDAVP. No changes in the joint concentrations of DDAVP + AVP in CSF were found following i.v. infusion of DDAVP when compared with the concentration before the infusion. Neither was any difference between CSF concentrations of AVP and DDAVP + AVP observed at any sampling time following the i.v. DDAVP administration. Hence, it is concluded that no measurable amounts of DDAVP can be found in the CSF for up to 2 h after i.v. administration of the peptide, and that for all practical purposes a blood-CSF barrier to DDAVP exists.

Adult↗
PubMed1983

Low cerebrospinal fluid concentration of brain-specific protein D2 in patients with normal pressure hydrocephalus.

The synaptic membrane glycoprotein D2 was measured in cerebrospinal fluid (CSF) and plasma in 13 patients with normal pressure hydrocephalus (NPH), in 14 patients with primary degenerative dementia of Alzheimer type (PDD), and in 24 patients without evidence of organic nervous disease (controls). Mean CSF D2 concentration was significantly lower in NPH patients: 299 +/- 48 ng/ml (SEM) (P less than 0.001) than in PDD patients: 658 +/- 50 ng/ml (SEM) and in controls 641 +/- 45 ng/ml (SEM). Plasma D2 concentrations were higher in PDD patients compared with those found in controls. Determination of CSF D2 concentrations might be of diagnostic value in discrimination between patients with NPH and PDD patients with enlarged ventricles associated with diffuse brain atrophy.

Adult↗
PubMed1983

Presence of alpha-adrenoceptors in human temporal arteries. Comparison between migraine patients and controls.

Alpha-adrenergic mechanisms have frequently been implied in migraine pathophysiology. We have examined the noradrenaline reactivity of isolated human temporal arteries removed from six migraine sufferers (not during attack) and from six patients without migraine operated for intracranial disorders. Noradrenaline constricted these vessels in a concentration-dependent manner, the response being altered by phentolamine 10(-8) M to 10(-6) M. There was no statistically significant difference between migraine patients and controls with respect to maximal contractile force (Emax) or pD2 (negative logarithm of the concentration eliciting half maximal force). The pA2 value for phentolamine was 8.3 in vessels from controls and 7.6 in arteries from migraine sufferers. The small difference between migraine patients and controls was not statistically significant. We obtained clear evidence of alpha-adrenergic receptors in human temporal arteries but their sensitivity was independent of the migraine disorder.

Adolescent↗
PubMed1983

CSF and plasma vasopressin concentrations in dementia.

In 16 patients with primary degenerative dementia mean CSF vasopressin concentration was lower (0.9 +/- 0.1 pg/ml (mean +/- SEM)) than in 28 control patients (1.3 +/- 0.1 (mean +/- SEM)) (p less than 0.01). In 18 patients with normal pressure hydrocephalus and potentially reversible dementia mean CSF vasopressin concentration (1.2 pg/ml +/- 0.1 (mean +/- SEM)) was not different from that found in controls. Several of the demented patients had inappropriate plasma vasopressin concentrations suggesting a defect in osmoregulation. These findings encourage further clinical trials of vasopressin in patients with primary degenerative dementia, but it is emphasised that the low CSF vasopressin concentration in these patients might be only a nonspecific phenomenon due to the diffuse loss of cells within the central nervous system.

Adult↗
PubMed1982

Characterization of 5-hydroxytryptamine receptors in human temporal arteries: comparison between migraine suffers and nonsufferers.

An increase in the sensitivity of temporal arteries to 5-hydroxytryptamine (5-HT) has repeatedly been suggested on indirect evidence as an essential component of a migraine attack. We examined the 5-HT reactivity of isolated human temporal arteries removed from migraine sufferers and from patients operated on because of cerebral disorders. 5-HT constricted these vessels in a concentration-dependent manner, the response being attenuated by 10-8 tp 10-6 M methysergide. There was no difference in reactivity to 5-HT or methysergide between vessels from the two patient groups. The pA2 value calculated for methysergide in controls was 7.8 +/- 0.1 and in migraine patients, 7.6 +/- 0.2, which closely agreed with data obtained graphically using Schild plots: 7.8 amd 7.7. respectively. No difference existed between the patient groups due to age or sex. Thus, clear evidence has been obtained demonstrating the presence of 5-HT receptors in human temporal arteries, although we could observe no difference in the character of the 5-HT receptors between migraine patients and controls.

Adolescent↗
PubMed1982

The conductance to outflow of CSF in adults with high-pressure hydrocephalus.

The intraventricular pressure was compared with conductance to outflow of CSF (Cout) in 12 patients with high-pressure hydrocephalus of less than 3 months duration. Cout was measured by a lumbo-ventricular or a ventriculo-ventricular perfusion test. In all patients Cout was very low (median 0.016 ml mm Hg-1 minute-1). Thus high-pressure hydrocephalus may be considered to be the consequence of a greatly increased resistance to resorption of CSF. The level of the measured ICP (mean: ICP 23.5 mm Hg) corresponded to the theoretical level calculated from the measured Cout. B-waves were observed during most of the recording periods and episodes of plateau waves were seen in all patients but one. In this particular group of patients, the unsatisfactory results of ventriculo-atrial shunting emphasize the high risks associated conditions leading to high-pressure hydrocephalus.

Adult↗
PubMed1982

The predictive value of conductance to outflow of CSF in normal pressure hydrocephalus.

Conductance to outflow of CSF was measured in a prospective study of 80 patients with normal pressure hydrocephalus. Measured outflow was compared with clinical findings, computed tomography, intracranial pressure measurements and with the results of shunting. Follow-up time was one year. Outflow measurements predicted the outcome of shunting in 96 per cent of the patients. Patients with the combination of known aetiology, short history, gait disturbances, severe dementia, urinary incontinence and hydrocephalus on CT can be shunted without further investigations. Periventricular hypodensity on CT scanning predicts an excellent result for shunting. Based on results of preoperative investigations and outcome of shunting we propose a programme for the investigation of future patients with normal pressure hydrocephalus.

Adult↗
PubMed1982

Vasopressin in the cerebrospinal fluid of patients with normal pressure hydrocephalus and benign intracranial hypertension.

We have studied plasma and cerebrospinal fluid vasopressin (CSF-AVP) and osmolality in 28 patients with cervical or lumbar pain syndromes (control patients), 11 patients with normal pressure hydrocephalus (NPH) and in 5 patients with benign intracranial hypertension (BIH). Vasopressin concentration in lumbar CSF to a high extent reflected the actual ventricular CSF-AVP concentration. In all groups CSF-AVP was lower than plasma AVP. Mean CSF-AVP in the control group was 1.3 pg/ml +/- 0.1 (SEM). In the NPH patients, who all suffered from severe dementia, CSF-AVP level was not different from that found in the control group (1.4 pg/ml +/- 0.2). In contrast to the findings in the two other groups CSF osmolality in BIH patients was higher than plasma osmolality (P less than 0.0). CSF-AVP in the BIH patients, characterized by an elevated intracranial pressure (ICP), was higher than in the control group (2.7 pg/ml +/- 0.4, P less than 0.001).

Adult↗
PubMed1981

Computed tomography of benign supratentorial astrocytomas of infancy and childhood.

The CT findings of 15 benign supratentorial astrocytomas in children less than 15 years of age are compared with the CT findings of 19 supratentorial tumors of other histological types in the same age group. Astrocytomas were more often hypodense, lacked calcification and showed greater contrast enhancement than other tumors. Seven of the 15 astrocytomas were hypodense, without calcification and showed contrast enhancement of more than 10 Hounsfield units, whereas this coexistence was not present in any of the 19 tumors of the other histological types.

Adolescent↗
PubMed1981

Isotope cisternography and conductance to outflow of CSF in normal pressure hydrocephalus.

In 50 patients with normal pressure hydrocephalus (NPH) the findings on lumbar isotope cisternography (IGG) were compared to the conductance to outflow of CSF (Cout) as measured by lumbo-ventricular perfusion. The purpose was to identify those ICG-characteristics that imply a low Cout and thus may indicate CSF shunting therapy. Normal ICG was found only in three patients, where Cout was not, or only moderately, decreased. There was a significant correlation between a low Cout and occurrence of ventricular retention and absent parasagittal accumulation at 24 hours or later, following injection. These findings may, however, also be present in patients with no, or only moderate, decreased Cout, where CSF shunting may seen unjustified. It is concluded, that the indication for CSF shunting cannot be based on the results of ICG alone.

Adult↗
PubMed1981

Increase in extracellular potassium in the brain during circulatory arrest: effects of hypothermia, lidocaine, and thiopental.

The effect of temperature (37 degrees C, 28 degrees C, and 18 degrees C), 160 mg/kg lidocaine, and 40 mg/kg thiopental on the efflux of cellular potassium in the cerebral cortex during complete global ischemia was examined. Cerebral ischemia was induced in dogs on cardiopulmonary bypass circulation by stopping the pump. Potassium concentration was measured on the brain surface by a valino-mycine-membrane electrode, which in its response corresponded well to an inserted microelectrode. Hypothermia reduced the ischemic potassium efflux rate to about 50 per cent at 28 degrees C, and about 25 per cent at 18 degrees C. At all temperature levels lidocaine caused an additional reduction in the potassium efflux rate of about 50 per cent, probably by reducing membrane ion permeability in accordance with its local anesthetic action. Thiopental had no effect on the potassium efflux during ischemia. This study opens the possibility that lidocaine, like hypothermia, may provide protection of the ischemic brain.

Animals↗
PubMed1980

Computed tomography and pneumoencephalography compared to conductance to outflow of CSF in normal pressure hydrocephalus.

The conductance to outflow of CSF (Cout) was measured in 66 patients with normal pressure hydrocephalus (NPH). All patients were investigated with computed tomography (CT); 34 of the patients also had pneumoencephalography (PEG). Periventricular hypodensity on CT indicates a low Cout. Cortical sulci smaller than 1.9 mm on CT indicate a low Cout, while wide cortical sulci do not exclude a low Cout. There was a good correlation between ventricular size on CT and PEG, but the ventricular size is unrelated to Cout. No findings on PEG indicate a low Cout.

Adult↗
PubMed1980

Colloid osmotic and hydrostatic pressures in chronic subdural haematomas.

Intracranial pressure (ICP) has been measured in eight patients with chronic subdural haematomas (CSH) for 24 hours prior to and for 24 hours following evacuation of the haematomas. In all patients ICP was increased prior to surgery (mean: 23 mm Hg), and it rose again to the preoperative level following evacuation of the haematomas in spite of disappearance of most symptoms and signs. In two of these patients and in another eight patients with CSH, colloid osmotic pressures were measured in samples obtained simultaneously from haematoma fluid and venous blood during surgery. The colloid osmotic pressure in haematoma fluid varied considerably between patients (lowest: 11.8 mm Hg, highest: 60 mm Hg), and thus the difference between colloid osmotic pressures in haematoma fluid and plasma also varied considerably. We suggest that the increased ICP in patients with CSH is the consequence of an increased resistance to absorption of cerebrospinal fluid due to compression of the underlying subarachnoid space. The findings with regard to colloid osmotic pressures suggest that osmotic gradients may be maintained across the boundaries of a chronic subdural haematoma.

Adult↗
PubMed1979

Calcification in a pineal tumour studied by transmission electron microscopy, electron diffraction and x-ray microanalysis.

The calcification in a totally calcified pineal tumour was studied. Transmission electron microscopy indicated that the tumour was a pinealoma. The type of calcification was investigated by bright-field and dark-field transmission electron microscopy in addition to electron diffraction and electron-induced x-ray fluorescence. The calcified material consisted predominantly of amorphous calcium phosphate. The type of calcification differs from the normal calcification present in pineal acervuli which consists of crystalline hydroxypatite.

Brain Neoplasms↗