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Biomedical subjects

R E Gonsette

Publications and source records attributed to R E Gonsette.

At least 37 records · Page 2Linked to original sources
PubMed1978

Complement system activation by contrast media in neuroradiology.

Complement system activation was studied in six series of 12 patients undergoing routine contrast study following IV injection of five recently developed contrast media. The decreasing order of effectiveness on the complement system was as follows: ioxaglic acid, metrizamide, iodamidol. Metrizoic and ioxithalamic acids did not provoke any complement depletion at the doses used in this study. Both pathways of activating the complement system were involved. We could not find any definite correlation with osmolarity, ionic or nonionic formulation, protein binding, or hydrophobicity.

Complement Activation↗
PubMed1977

Potentiation of Amipaque epileptogenic activity by neuroleptics.

Experiments conducted on rabbits confirmed that chlorpromazine potentiates the weak epileptogenic action of Amipaque (metrizamide). Chlorpromazine withdrawal for a period of 48 h suppresses this potentiating effect in the rabbit. Neuroleptic drugs should therefore be avoided in patients examined with Amipaque. In patients under chronic treatment, neuroleptics ought to be discontinued at least 48 h before examination with Amipaque. With the doses and methods used in the present study, diazepam was not as effective as phenobarbital in preventing epilepsy produced by Amipaque. When premidication is needed or when convulsions occur after Amipaque examinations, combined diazepam and phenobarbital therapy ought to be instituted in order to achieve the best control of epileptic reactions.

Animals↗
PubMed1977

Intensive immunosuppression with cyclophosphamide in multiple sclerosis. Follow up of 110 patients for 2-6 years.

140 MS patients were treated with intensive I.V. cyclophosphamide immunotherapy and 110 were followed over 2-4 years. Annual relapse rate incidence was calculated over a period of 2 years before and after treatment and repeated neurological scores were made during this period. The conclusions are that 62% of the patients were stabilized during 2-4 years and that clinical improvement of the neurological signs was observed in most of the cases. It is concluded that intensive immunosuppression is able to interfere with the pathological processes involved in the pathogenesis of disseminated sclerosis.

Adult↗
PubMed1977

Cervical myelography with metrizamide by suboccipital puncture.

Cervical myelography with metrizamide (Amipaque) by suboccipital puncture was performed in 125 patients. Side effects were insignificant and there was no discomfort for the patient. The maximum amount to be injected is 3.75 g metrizamide (1.5 g iodine), and care must be taken in order to keep the contrast medium out of the basal cisterns. No premedication was used and no signs of irritation of the central nervous system were observed. With this technique the spinal cord and the nerve-roots are well demonstrated.

Humans↗
PubMed1977

Ventriculography with metrizamide.

Ventriculography with metrizamide (Amipaque) was performed in 150 patients. Side effects were mild and no severe reactions were observed. The low toxicity and the low epileptogenic activity of this contrast medium make positive contrast ventriculography a safe neuroradiologic procedure.

Cerebral Ventriculography↗
PubMed1976

Cervical myelography with a new resorbable contrast medium: Amipaque.

Cervical myelography with Amipaque was carried out on 1000 patients using the suboccipital puncture. The quality of the films is excellent and provides detailed informations on the spinal cord pathology and the cervical rootlets as well. Side effects are trivial and no case of epilepsy was observed in our group of patients.

Contrast Media↗
PubMedDate not supplied

In vivo activation of serum complement by contrast media: a clinical study.

The study was designed to confirm complement system activation in vivo in man after intravenous injection of contrast media for brain CT scan enhancement. Four currently available components were tested: C1q, C3 activator, C3c, and C4 after intravenous injection of seven different contrast media: diatrizoate, metrizoate, iothalamate, ioxithalamate, ioxaglate, metrizamide, iopamidol. The complement system was indeed activated by certain control media, but no correlation with clinical reactions or with hypertonicity, ionic or nonionic formulation, or protein binding could be found. However, a correlation was found to some extent between the lipid solubility and the activity on the complement system. Addition of calcium salts definitely inhibited the complement system activation induced by metrizoate and ioxaglate.

Brain↗
PubMedDate not supplied

New contrast media in cerebral angiography: animal experiments and preliminary clinical studies.

The cerebrovascular toxicity of three water-soluble contrast agents with a low hypertonicity (metrizamide, ioxaglate, iopamidol) was tested. Blood-brain barrier damage after carotid injection was assessed using 32P autoradiography and fluorescent microscopy after Evans blue staining. The damage to carotid endothelium was determined using a silver staining method. Brain tissue was studied by light and electron microscopy. The studied contrast media did not damage either the blood-brain barrier or the carotid endothelium at clinical doses. Nonionic metrizamide and iopamidol have a very low brain tissue toxicity. Preliminary clinical experience indicates that the incidence of adverse reactions (pain, feeling of heat) is low. No severe adverse reactions were observed. No improvement of the radiologic information compared with the current contrast agents was observed.

Animals↗