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Biomedical subjects

Y Lajat

Publications and source records attributed to Y Lajat.

At least 37 records · Page 2Linked to original sources
PubMed1992

Photodynamic treatment of normal endothelial cells or glioma cells in vitro.

Photodynamic therapy is based on the interaction of a sensitizer (hematoporphyrin derivative) selectively retained by tumor cells, which becomes toxic after light exposure. We studied the influence of exogenous prostaglandins and indomethacin on photodynamic therapy of normal human endothelial cells and glioma cells. Although differing in origin and kinetic properties, endothelial cells exhibited photodynamic therapy sensitivity quite comparable to that of C6 cells. However, in contrast to studies performed using radiotherapy, exogenous prostaglandins decreased rather than protected the surviving fraction of both cell types treated by photodynamic therapy. Indomethacin, a potent inhibitor of endogenous prostaglandin synthesis, increased the surviving fraction of C6 glioma cells but not that of endothelial cells. Exogenous or endogenous prostaglandins seem to influence in vitro photodynamic therapy in a different way than does radiotherapy.

Animals↗
PubMed1992

[Intracerebral morphine therapy in cancer patients].

An overview of recent studies concerning opioids and their pharmacokinetics is presented. In the light of these findings it is shown that intracerebral administration may be justified. The authors experience with 63 cases is detailed: all cancer patients in the final stage. Initial dosage by the intraventricular route was 500 to 700 microgram-day but in one case twice daily injections of 1.200 microgram were needed. The dosage needed doubled over the observation period of 2 to 3 months. The mean length of survival was 75 days. Among complications nausea and vomiting were observed in 15 to 35% of the cases, sweating and pruritus in 15%, urinary retention in 15 to 20%. In some cases euphoria, motor excitement and hallucinations occurred. Chronic constipation was present in all cases. Two cases of meningitis were successfully treated by antibiotics. Pain relief was judged excellent or good in 75% of the cases. In 20% other analgesics had to be added to the treatment. In 5% the method failed.

Humans↗
PubMed1991

[Perineal pain and involvement of the internal pudendal nerves].

A number of chronic pain syndromes in the perineal area can be related to pudental nerves suffering. The constancy of symptoms among various patients, and in duration for a particular one, alterations revealed by electrophysiologic studies, pain relief by diagnostic blocks, data from anatomic studies, preliminary results of medical and surgical applied therapies, give consistent arguments for possible organic lesions of pudental nerves.

Chronic Disease↗
PubMed1989

Cerebral blood flow and cerebral oxygen consumption during nitroprusside-induced hypotension to less than 50 mmHg.

The authors determined the effect of profound induced hypotension (i.e., mean arterial blood pressure less than 50 mmHg) during craniotomy for cerebral aneurysm on cerebral blood flow and cerebral metabolic rate for oxygen before, during, and after (20 min and 40 min after) the hypotensive period. The study was performed on nine adults (mean age, 29.2 yr) who were awake and conscious without peripheral neurologic deficits at the time of surgery. The study was conducted with the dura open with the use of a radial artery cannula, a 7-Fr thermodilution flow-directed pulmonary artery catheter, and an internal jugular vein catheter. The 133xenon intraarterial injection technique was used to determine regional cerebral blood flow (rCBF) in the nonoperated hemisphere. rCBF remained unchanged (from 22.8 +/- 4.1 ml.100 g-1.min-1 to 23.8 +/- 4.6 ml.100 g-1.min-1) during the hypotensive period (MAP from 87.8 +/- 10.4 mmHg to 40.0 +/- 4.4 mmHg; P less than 0.001) despite an increase in cardiac index since cerebral perfusion pressure and cerebrovascular resistance decreased to a similar degree. No gross cerebral metabolic disturbances were observed. A period of decreased cerebrovascular resistance and increased rCBF followed induced hypotension. rCBF increased from 23.8 +/- 4.6 ml.100 g-1.min-1 to 30.0 +/- 5.8 ml.100 g-1.min-1 (P less than 0.001) 20 min after sodium nitroprusside (SNP) was stopped without rebound hypertension. These modifications disappeared 20 min later. Reduction of mean arterial blood pressure to 40 mmHg by SNP was apparently safe for the brain, although the possibility of low perfused regions and local brain and cerebrospinal fluid lactoacidosis, particularly in the retracted hemisphere, cannot be excluded.

Adult↗
PubMed1989

[Bone integration within calcium phosphate ceramic by creation of posterior inter-articular lumbar spine fusions in dogs].

Following earlier experiments in which several calcium phosphate ceramics were tested, the aim of this study was to evaluate bone integration within a macroporous biphasic calcium ceramic (M.B.C.P.) in comparison to autologous bone grafts, by producing posterior lumbar spine fusions in dogs. Five dogs were used. 40 posterior lumbar joints were exposed; 38 articular surfaces were removed, 27 M.B.C.P. and 5 autologous bone grafts were implanted; 6 joints were kept free of implant for control purposes. Fixation with a metal rod was performed using Luque's method. Tetracycline was used for a double marking of bone growth. Joints were removed at 4 weeks in 1 dog, 8 weeks in two and 13 weeks in the remaining 2 dogs. Demineralized and non demineralized sections were examined. After 1 month, sections with M.B.C.P. showed early signs of mineralization of the scar tissue between the biomaterial and one of the facets of the joint. Fluoroscopy revealed an absence of bone growth in the pores at the center of the ceramic implant. After 3 months, a number of M.B.C.P. blocks had become integrated into both sides of the joint; however some microfractures in the biomaterial with discontinuity between the mineralized areas was seen. Macroporous calcium phosphate ceramic leads to revascularization allowing bone reconstruction. Similarities in the kinetics and mechanisms of bone integration between the ceramic and autologous bone grafts are demonstrated.

Animals↗
PubMed1985

[Stereotaxic treatment of expanding cysts in craniopharyngiomas by endocavitary beta-irradiation (Re-186; Au-198; Y-90)].

The authors report the results of 17 intracystic injection of colloidal 186 rhenium, 2 colloidal 198 gold, and 1 colloidal 90 yttrium for endocavitary treatment of 18 cystic craniopharyngiomas (16 pts during a period ranging from January 1975 till July 1982. Follow-up studies ranging from 12 to 72 months (m: 36 m) revealed that all craniopharyngiomas cysts were effectively treated with cessation of fluid formation, progressive shrinkage of the formerly expansive cysts, and finally cyst obliteration in 75% of the cases. No early or late side-effects were observed during the entire observation period. Late reexpansion of one craniopharyngioma cyst, observed at 11 months, was successfully treated by a second injection. Leakage of colloid isotope into the CSF spaces during the "test" or "therapeutic" injections occurred in 18% of the global number of injections, however no clinical complications were observed. On the basis of a clinical dosimetric study a 30 000 rads wall-dose, not exceeding 40 000 rads is actually considered as the safer dose for endocavitary treatment of craniopharyngioma.

Adolescent↗
PubMed1984

[Facial vascular pain and sympathalgia. Therapeutic trial].

After a brief historical review of non-symptomatic pain, the authors describe the typical form of vascular pain in the face, a definite clinical entity. As is in the case in other specialties, they now prefer the term vascular pain to that of sympathalgia, still often used in our own discipline. Vascular pain occurs by paroxysmal attacks centred upon the orbit, accompanied by typical vasomotors signs. The treatment proposed is based upon the use alone or in association of dihydroergotamine, methysergide and beta-blockers.

Face↗
PubMed1983

[Localized fast rhythms in EEG tracings following surgery for intracranial meningioma].

Forty-six patients were followed up after removal of an intracranial meningioma. Nine of the 46 patients in their 3rd month postoperative EEG had localised fast rhythms which remained stable. The fast rhythms appeared in small 20-25 Hz and 20-40 microV bursts; they were localised over the craniotomy flap as shown by the control X-ray of the sites of the electrodes; they were unaffected by eye-opening and slightly reduced by fist-clenching. These fast rhythms were sometimes mixed with sharp waves and theta activity and seemed to be equivalent to the 'breach rhythm' described first by Fischgold et al. (1952) and then by Cobb et al. (1979). In our study, these rhythms were more frequently observed in patients with an olfactory or sphenoidal meningioma, in patients with pre-operative seizure and in patients with an extensive post-operative intracranial atrophy (as shown by the scanner). On the other hand, incomplete removal or recurrence of the tumour or post-operative epilepsy did not seem to play a role in the appearance of these rhythms.

Adult↗
PubMed1983

[Use of stereotaxic neurosurgery in the treatment of pain in cervicofacial cancers].

Mesencephalic tractotomy employing the stereotaxic method was conducted 12 times in 11 patients with pain due to cervicofacial cancer only partially relieved by high doses of opiates. Immediate results were spectacular in 10 cases and partial on the other 2 occasions. However, relief was not permanent even in patients in whom the greatest improvement was obtained, and the usual analgesics had to be prescribed after 3 months. The operation, which requires only a short period of anesthesia, was always well supported, complications being anesthesia of one side of the body in 2 patients and convergence paralysis in two cases, one of which was transient. Mesencephalic tractotomy constitutes a new weapon for the treatment of diffuse cervicofacial cancer pain not responding to major medical treatment. Elective thermocoagulation of the Vth and IXth nerves was also successfully employed for systematized pains.

Adult↗
PubMed1982

[Sequential scintiscans. An easy method for testing C.S.F. shunts].

Different procedures have been since 1965 by the authors to test with isotopes the patency of shunts for hydrocephalus. The authors now measure the time 99m Technetium takes to appear in the thyroid gland after injection in the flushing device. This method shows easily and very quickly, with no computing, the dynamics of C.S.F. shunts. No hospitalisation is necessary and it is often possible to determine the cause of the disturbance in the shunt.

Cerebrospinal Fluid Shunts↗
PubMed1981

Sacral intraspinal lipoma associated with congenital iliac anomaly.

2 cases of a peculiar unilateral protuberance near the iliac bone with intraspinal abnormalities are reported. 8 cases have been described in the literature with this characteristic congenital association; they indicate the frequency of an occult spinal dysraphism which must be proved by myelography. In each case, surgical treatment of bone abnormality or of intraspinal lesions, or of both, should be discussed.

Adolescent↗
PubMed1981

[Contribution of arteriography to the investigation of peripheral nerve tumours (author's transl)].

Based on their personal experience of the use of arteriography in 11 patients, the authors describe the angiographic appearances of both benign and malignant peripheral nerve tumours. They emphasise the reasons for errors, and the criteria enabling the precise nature of the lesion to be determined pre-operatively in the majority of cases. Other contributions supplied by angiography are discussed.

Angiography↗
PubMed1980

[Surgical management of primary peripheral nerve tumours (author's transl)].

A rational approach to the surgical treatment of peripheral nerve tumours can be determined by a knowledge of current concepts concerning their pathology and by clinical and arteriographic preoperative findings, and guided by extemporaneous histological examination results. It can be modified by the presence of metastases or associated phakomatosis.

Extremities↗
PubMed1980

[Intraneural synovial cyst in the peroneal nerve. Case report (author's transl)].

The authors report one case of paralysis of the peroneal nerve due to an intraneural synovial cyst, in connection with the superior tibio-fibular joint. After an anatomic work and a complete revue of the literature, etiopathogenic and diagnostic problems seem to be resolved, and this justifies their terminologic choice.

Adult↗