PubMed Health⌕ Search

Biomedical subjects

M Lebel

Publications and source records attributed to M Lebel.

106 records · Page 6Linked to original sources
PubMed1975

[Pure (dynamic ?) agraphia of frontal origin. Apropos of one case].

A case of pure graphic disorder without any disorder of speech, reading or praxis is described. The conditions under which it occurred after surgery for frontal oligodendroglioma would seem to confirm that a single frontal lesion is involve affecting in particular the foot of F2. This case is compared with similar ones which have appeared in the literature and are classified within the wider category of kinesthetic disorders caused by frontal lobe lesion.

Agraphia↗
PubMedDate not supplied

Effect of initial blood pressure level on cardiovascular reflexes caused by intraperitoneal neurotensin.

The reflex changes of systemic blood pressure (BP) and heart rate (HR) induced by intraperitoneal (IP) injections of neurotensin-containing solutions (NTCS) were measured in anesthetized guinea pigs whose BP was raised up by intravenous (IV) infusions of either angiotensin II (ATII) or noradrenaline (NA), and compared to those observed in control animals (i.e., saline-infused guinea pigs with low initial BP level). The amplitudes of reflex pressor and tachycardic responses to IP NTCS were either not affected or reduced in animals whose BP was raised with ATII or NA. However, no hypotensive effect was observed, following IP NTCS, in any of the animals tested. The results indicate that high initial BP levels tend to attenuate the reflex increases of BP and HR caused by IP NTCS, the level of inhibition being largely determined by the type of vasopressor agent utilized to raise up the BP. They also suggest that the initial BP level is unlikely to be an important factor in determining whether the activation of capsaicin-sensitive visceral afferents will produce hypotensive or hypertensive effects in this animal model.

Angiotensin II↗
PubMedDate not supplied

Further observations on the mechanism of the cardiovascular reflexes caused by exposure of the peritoneum to neurotensin.

Intraperitoneal (IP) injections of either 1, 3 or 9 ml of neurotensin-containing solutions (NTCS) with 5.4, 54, 540 or 5400 nM of neurotensin (NT) were found to cause concentration-dependent, but volume-independent, increases of blood pressure (BP) and heart rate (HR) in anesthetized, close-abdomen guinea pigs. The duration of both effects varied between 15 to 30 min depending both on the NT concentration and volume of NTCS utilized. Indirect evidence suggested that NT inactivation within the peritoneal cavity contributed to shorten the duration of NT effects. Animal pretreatment with a ganglion blocker, adrenoceptor antagonists, clonidine or capsaicin, reduced the BP and HR increases caused by IP injection of NTCS whereas both effects were either unaffected or slightly potentiated by animal pretreatment with atropine, morphine or captopril. Addition of a local anesthetic to NTCS inhibited the hemodynamic effects of NT whereas acute bilateral cervical vagotomy was without significant effect. These results suggest that NT has the ability to trigger cardiovascular reflexes following its IP injection in guinea pigs. The activation of peritoneal, sympathetic, capsaicin-sensitive primary afferents appears to be at the basis of these reflexes, the amplitudes of which seem poorly related to the volume of NTCS utilized (at least within the range of volume examined).

Animals↗
PubMedDate not supplied

Chronic nitric oxide inhibition aggravates hypertension in erythropoietin-treated renal failure rats.

Alterations in nitric oxide (NO) and endothelin-1 (ET-1) production have recently been reported in erythropoietin (r-HuEPO)-induced hypertension in renal failure rats. The present study was designed to evaluate the effect of NO synthase inhibition with the L-arginine analog NG-nitro-L-arginine methyl ester (L-NAME) on blood pressure (BP) and ET-1 production in control and in uremic rats treated or not treated with r-HuEPO. Renal failure was induced by a two-stage 5/6 nephrectomy. Control and uremic rats were studied separately and subdivided into four groups: vehicle, r-HuEPO, L-NAME + vehicle and L-NAME + r-HuEPO. L-NAME (100 mg/kg/day), r-HuEPO (100 U/kg, subcutaneously, three times per week), the vehicle or both were administered during 4 weeks in control rats and during 2 weeks in uremic rats. Systolic BP was recorded before and after the onset of treatment at weeks 2 and 4 in control rats and at weeks 1 and 2 in uremic rats. Hematocrit, serum creatinine, plasma, blood vessel (thoracic aorta and mesenteric artery bed) and renal cortex immunoreactive (ir) ET-1 concentrations were measured at the end of the protocol. L-NAME enhanced BP in control and uremic rats and the increase was significantly higher in uremic rats under r-HuEPO therapy (222 +/- 7 mmHg vs 198 +/- 6 mmHg, p<0.05). L-NAME induced an increase in thoracic aorta ir-ET-1 concentrations in control and uremic rats. In contrast, ir-ET-1 concentrations were unchanged in the mesenteric arterial bed and the renal cortex of control and uremic animals. R-HuEPO increased thoracic aorta ir-ET-1 contents in L-NAME treated control and uremic rats. These results underline the important role of NO release in opposing the action of vasopressors on blood vessel tone which appears more important in uremic rats treated with r-HuEPO. L-NAME treatment increased large vessel, but not small resistance artery ir-ET-1 concentrations, suggesting differential regulation of ET-1 production in different vascular beds under chronic NO synthase inhibition.

Animals↗
PubMedDate not supplied

[Treatment of idiopathic scoliosis by the Harrington technique. Experience from the Ste-Justine Hospital, Montreal].

The purpose of this study was to evaluate the first seven hundred and fifty cases of scoliosis treated surgically by the harrington technique at Ste-Justine Hospital for Children in Montreal since 1964, in regards to modifications of original technique. Five surgeons were involved in the treatment. The mean presurgical angulation was 57.9 degrees; the mean post-surgical angulation was 20 degrees representing an immediate gain of 37.9 degrees. Average loss of correction three years after surgery was 13.3 degrees. Hibbs and Moe type of posterior spine fusion with fresh autogenous iliac bone appears to be the best procedure for maintenance of initial correction, together with early ambulation in a well-molded Risser-Cotrel type of plaster jacket. Prognosis as related to percentage of retained correction is better in girls than boys and also when fused after the age of thirteen years. More correction was obtained and maintained in curves between 30 degrees and 50 degrees. Rate of neurological complications was 0.4%. There was no mortality. There were 3% rod fractures, 5% pseudarthrosis proven at surgery and 5% acute or subacute infections.

Adolescent↗