Biomedical subjects

P Adeleine

Publications and source records attributed to P Adeleine.

At least 37 records · Page 2Linked to original sources

PubMed2000

Venous allografts preserved at 4 degrees C for infrainguinal bypass: long-term results from 170 procedures.

From April 21, 1982 to December 31, 1997, we performed 170 infrainguinal bypass procedures using isolated (n = 35) or composite (n = 135) venous allografts preserved at 4 degrees C as a substitute for saphenous autografts in 146 patients. The mean age of the patient population was 74 years. The indication was critical lower limb ischemia in 71% of cases. Seventy-five percent of procedures were below the knee and 26% were infrapopliteal. Mean length and diameter were 19.5 +/- 0.5 cm and 4.8 +/- 0.5 mm, respectively. After December 8, 1993, a reinforcement net was placed over the graft to prevent expansion in 71% of cases. Primary and secondary 5-year patency, calculated according to the Kaplan-Meier method, were 33 +/- 6% and 43 +/- 6%, respectively. Factors correlated with secondary patency were studied using the log-rank test. Previous ipsilateral infrainguinal revascularization was associated with a 40% decrease in secondary patency at 2 years (71% vs. 31%). Patency at 5 years was correlated with the level of anastomosis (47% for low popliteal anastomosis vs. 30% for infrapopliteal anastomosis). The likelihood of stenosis or dilatation of the allograft was 8% and 29.5%, respectively, at 5 years. The 5-year limb salvage and survival rates were 84% and 57%, respectively. The encouraging results of this series suggest that venous allografts provide a useful alternative for infrainguinal bypass when autologous grafts or other more reliable conduits are unavailable.

Adult↗

PubMed2000

Heparins and blood polymorphonuclear stimulation in haemodialysis: an expansion of the biocompatibility concept.

BACKGROUND: At the concentrations used in haemodialysis and in a dose-dependent way, unfractionated heparin (UFH) and, to a lesser degree, a low-molecular-weight heparin (LMWH) stimulate polymorphonuclear cells (PMN) in vitro, and could act in synergy with the stimulatory effect of dialysis membranes in vivo. To examine this hypothesis, we studied the effects of different heparin types and regimens on blood PMNs during haemodialysis sessions. METHODS: Ten haemodialysed patients were studied during regular dialysis sessions on a cellulose triacetate membrane (CT 110 G; 1.10 m(2); Baxter), with four different random heparin protocols: one high-UFH regimen (HHR) at 90 IU/kg body-weight (b.w.) and one low-UFH regimen (LHR) at 50 IU/kg b.w., and with a LMWH (nadroparin calcium) at 85 (HHR) or 45 (LHR) IU/kg b.w. Blood granulocytes, platelet counts, and plasma granulocyte degranulation products (elastase, lactoferrin) were measured serially during 4 h dialysis sessions. RESULTS: After 10 min, the reduction in PMNs with UFH was 29.5% for HHR (P<0.01) and 28.5% for LHR (P<0.01), and only 16.8 and 18.6% with LMWH (NS), significantly higher for HHR with UFH than with LMWH (P<0.01). At 60 min, the elastase increase with HHR was greater, 61% with UFH (P<0.01) and 37.8% with LMWH (P<0.01), significantly higher than LHR for UFH (P<0.05) or LMWH (P<0.05). The overall decrease in platelets (with LMWH P<0.01) and the overall increase in lactoferrin (P<0.001) were not different between heparinization procedures. CONCLUSION: Under a conventional heparin regimen, the PMN variation during the course of the dialysis session suggests a more biocompatible effect of LMWH over UFH. In addition, the variation of elastase favours the lower dose, whatever the type of heparin. Heparin type and dose should therefore be considered in studies addressing biocompatibility in haemodialysis: a low dose of LMWH may be viewed as a better biocompatible treatment with regard to leukocyte stimulation.

Adult↗

PubMed2000

Vasodilatory response of border zones to acetazolamide before and after endarterectomy : an echo planar imaging-dynamic susceptibility contrast-enhanced MRI study in patients with high-grade unilateral internal carotid artery stenosis.

BACKGROUND AND PURPOSE: The importance of hemodynamic changes related to a high-grade internal carotid artery (ICA) stenosis remains a matter of controversy. Areas between the vascular territories of major cerebral arteries, namely, the border zones, may be selectively vulnerable to hemodynamic alteration. The aim of this study was to search for any hemodynamic impact of carotid endarterectomy (CEA) on vasodilatory response, in particular, within the border zones, by means of multislice dynamic susceptibility contrast MRI. METHODS: Thirteen patients with a high-grade unilateral ICA stenosis (>80%) were examined. Relative regional cerebral blood volume (rrCBV) was determined separately for white matter, gray matter, and anterior and posterior border zones by the acetazolamide test. A vasomotor reactivity index was evaluated from the rrCBV values. Values from the ipsilateral hemisphere were compared with contralateral ones, before and after CEA. RESULTS: Before CEA, rrCBV values in the anterior border zones were significantly (P<0.05) higher in the ipsilateral hemisphere than in the contralateral hemisphere. A decrease in vasomotor reactivity indexes was also observed in the lesion side, but the difference from the contralateral side was not statistically significant. In posterior border zones, no differences in rrCBV or vasomotor reactivity were found between the ipsilateral and the contralateral hemispheres. After CEA, the rrCBV asymmetry in the anterior border zones cleared. CONCLUSIONS: High-grade ICA stenosis with efficient primary collateral pathways may have an early limited hemodynamic impact within border-zone areas. The favorable course of these abnormalities after surgery suggests an additional benefit of CEA at this stage.

Acetazolamide↗

PubMed1999

Intraocular foreign bodies. Factors influencing final visual outcome.

PURPOSE: To identify the prognostic factors of poor visual outcome (visual acuity < or =6/240) in eyes with intraocular foreign bodies. METHODS: The records of 95 consecutive patients were retrospectively reviewed for 6 years (1990-1995). All eyes underwent a primary surgical repair and foreign-body removal (electromagnet or vitrectomy). The mean follow-up period was 25 months (6-72 months). Single analysis and multiple logistic stepwise regression analysis were performed to determine predictors of poor vision. RESULTS: Thirty patients (31.6%) showed 6/240 or worse vision at the end of their follow-up period. Three significant predictive factors had independent and combined effects on post-operative visual outcome: a corneo-scleral entry wound (odds ratio (OR)=14.5, p=0.001), largest diameter of IOFB (OR=1.21, p=0.01) and the presence of secondary retinal detachment (OR=9.48, p=0.0002). Post-operative complications included traumatic cataracts (51%), retinal detachments (28%) and phthisis bulbi (8%). CONCLUSION: Using multivariate analysis, corneo-scleral entry wound, largest diameter of foreign body and secondary retinal detachment were found to be predictors of poor visual outcome after intraocular foreign body removal. Our results suggest that patients with high-risk intraocular foreign body trauma should be candidates for pars plana vitrectomy rather than electromagnet procedure.

Adolescent↗

PubMed1999

Influence of the interval between preoperative radiation therapy and surgery on downstaging and on the rate of sphincter-sparing surgery for rectal cancer: the Lyon R90-01 randomized trial.

PURPOSE: The optimal timing of surgery after preoperative radiotherapy in rectal cancer is unknown. The aim of this trial was to evaluate the role of the interval between preoperative radiotherapy and surgery. PATIENTS AND METHODS: Patients with rectal carcinoma accessible to rectal digital examination, staged T2 to T3, NX, M0, were randomized before radiotherapy (39 Gy in 13 fractions) into two groups: in the short interval (SI) group, surgery had to be performed within 2 weeks after completion of radiation therapy, compared with 6 to 8 weeks in the long interval (LI) group. Between 1991 and 1995, 201 patients were enrolled onto the study. RESULTS: A long interval between preoperative radiotherapy and surgery was associated with a significantly better clinical tumor response (53. 1% in the SI group v 71.7% in the LI group, P =.007) and pathologic downstaging (10.3% in the SI group v 26% in the LI group, P =.005). At a median follow-up of 33 months, there were no differences in morbidity, local relapse, and short-term survival between the two groups. Sphincter-preserving surgery was performed in 76% of cases in the LI group versus 68% in the SI group (P = 0.27). CONCLUSION: A long interval between preoperative irradiation and surgery provides increased tumor downstaging with no detrimental effect on toxicity and early clinical results. When sphincter preservation is questionable, a long interval may increase the chance of a successful sphincter-saving surgery.

Adenocarcinoma↗

PubMed1998

Can cerebrovascular reactivity be assessed by dynamic susceptibility contrast-enhanced MRI?

The acetazolamide (ACZ) test is performed to evaluate the decrease in cerebral perfusion pressure (CPP) by investigation of vasomotor reactivity (VMR). Our aim was to study cerebral blood flow and blood volume changes induced by the ACZ test in healthy control subjects using dynamic susceptibility contrast-enhanced gradient-echo MRI (DSC-MRI). A FLASH sequence was used to produce susceptibility-weighted images during an intravenous injection of 0.1 mmol/kg gadopentetate dimeglumine (Gd-DTPA). After the first dynamic study, 1 g acetazolamide was given intravenously and 10 min later a second bolus of Gd-DTPA was injected. Using the indicator-dilution theory, relative cerebral blood volume and relative cerebral blood flow were estimated. In healthy subjects the ACZ test induced a significant increase in relative blood volume (from 80.5 +/- 10.7 to 113.4 +/- 11.9) and relative blood flow (from 5.73 +/- 0.96 to 7.5 +/- 0.97), symmetrically in the cerebral hemispheres. This approach might be promising in the understanding of cerebral haemodynamics in patients with vascular disorders.

Acetazolamide↗

PubMed1998

Course of valvular strands in patients with stroke: cooperative study with transesophageal echocardiography.

BACKGROUND: Native valve strands might be related to the acute stage of thrombosis or might suggest a long-term valvular change. We aimed to estimate changes in the strands in patients with stroke through a serial transesophageal echocardiographic (TEE) study. METHODS AND RESULTS: A study was conducted among patients who were referred for TEE for stroke or cardiac pathology. Patients had TEE examinations with a 5-MHz multiplane TEE probe. Echocardiography was repeated 3 months later in patients with stroke. TEE was performed in 180 patients admitted to cardiology units and in 160 patients referred to neurology units. Among 34 patients with valvular strands, 30 were referred to neurology for stroke, whereas 4 patients were admitted to cardiology (18.8% versus 2.2%, difference 16.5%, 95% confidence interval 10% to 22.9%, P =.001). Strands were located on the mitral valve in 16 patients, the aortic valve in 6 patients, and both left heart valves in 8 patients. Among the 38 valves with strands, 17 (44. 7%) were morphologically normal, 4 (10.5%) were thickened, 7 (18.4%) were redundant, and 10 (26.3%) had both abnormalities. TEE showed other abnormalities in 16 (53.3%) patients, whereas 14 patients had only strands. Twenty-six (86.6%) patients had a second TEE study 3 months later. Strands were not found in 4 (15.4%) patients (95% confidence interval 4.3% to 34.9%). CONCLUSIONS: Valvular thickening or redundancy may predispose valves to strand formation. Native valve strands usually persist and thus reflect a chronic valvular change.

Adolescent↗

PubMed1998

Visual outcome and prognostic factors after magnetic extraction of posterior segment foreign bodies in 40 cases.

AIMS: To evaluate the clinical features as well as the visual and anatomical outcome in eyes with magnetic posterior segment foreign bodies, to identify prognostic factors after removal using an electromagnet. METHODS: The records of 40 patients with posterior segment foreign bodies were retrospectively reviewed for 6 years (1989-94). Post-traumatic cataracts and secondary retinal detachments were treated using conventional surgical techniques. Pars plana vitrectomy was used only for late complications. The mean follow up was 30 months (6-71). Clinical factors were studied using univariate analysis. RESULTS: The most common findings before treatment of these 40 eyes were lens wound, hyphaema, vitreous haemorrhage, and retinal impairment. The foreign body was in the vitreous (85%) or minimally embedded in the retina (15%). Initial visual acuity was worse or equal to 20/40 in 70% of the cases. Subsequent to surgical treatment, a cataract was reported in 60% of the patients. Postoperative complications included retinal detachment (15%) and phthysis (5%). The prognosis was worse in cases with intraocular foreign body of largest diameter > or = 3 mm, an initial visual acuity less than 20/200, or the presence of post-traumatic retinal detachment. Presence of initial intravitreous haemorrhage, hyphaema, or intraocular tissue prolapse did not appear to affect the prognosis. CONCLUSION: The long term visual acuity results indicated that wound repair associated with conventional magnet extraction in an emergency is a viable treatment for posterior segment magnetic foreign bodies in this selected group. At the time of diagnosis, size of foreign body (< 3 mm) and initial visual acuity > or = 20/200 were predictors of good visual outcome after primary magnetic extraction.

Accidents, Occupational↗

PubMed1998

Thrombolysis with intravenous rtPA in a series of 100 cases of acute carotid territory stroke: determination of etiological, topographic, and radiological outcome factors.

BACKGROUND AND PURPOSE: Although new, large, double-blind, randomized studies are needed to establish the efficiency of intravenous thrombolysis, open trials of sufficient size may also provide novel data concerning specific outcomes after thrombolysis. METHODS: An open study of intravenous rtPA in 100 patients with internal carotid artery (ICA) territory strokes between 20 and 81 years of age, with a baseline Scandinavian Stroke Scale (SSS) score of <48 at entry was conducted. Inclusion time was within 7 hours after stroke onset. rtPA (0.8 mg/kg) was infused for 90 minutes, with an initial 10% bolus. Heparin was given according to 3 consecutive protocols. The SSS evaluation was done on days 0, 1, 7, 30, and 90. CT scan was performed before treatment, on days 1 and 7. Etiological investigations included echocardiography and carotid Doppler sonography and/or angiography. Outcome at 1 year was documented by SSS score, the modified Rankin Scale (mRS) score, and a 10-point invalidity scale. Multivariate logistic regression was used to identify predictors of poor versus good outcome. RESULTS: At day 90, 45 patients (45%) had a good result, defined as complete regression or slight neurological sequelae (mRS score of 0-1), 18 patients had a moderate outcome (mRS 2-3), and 31 patients had serious neurological sequelae (mRS 4-5). Six patients died, 2 with intracerebral hematoma after immediate heparin. Five of 11 patients (45.5%) treated between 6 and 7 hours had a good result. The overall intracerebral hematoma rate was 7%. Higher values of fibrin degradation products at 2 hours were observed in the subgroup with intracerebral hematomas. Significant predictors of poor outcome on multivariate logistic regression analysis were baseline SSS score of <15 (odds ratio [OR], 3.38; 95% confidence interval [CI], 1.07 to 10. 74; P=0.04), indistinction between white and gray matter on CT scan (OR, 6.59; 95% CI, 2.19 to 19.79; P=0.0008), and proximal internal carotid thrombosis (OR, 3.29; 95% CI, 0.99 to 10.95; P=0.05). CONCLUSIONS: Our study confirms the safety of intravenous rtPA at a dose of 0.8 mg/kg and suggests efficacy for this drug even within 7 hours. Outcome and hematoma rates were at least as favorable as for trials of therapy with a 3-hour time window. Subgroups with a poor prognosis include low baseline neurological score, baseline CT changes, and proximal ICA thrombosis. However, approximately 30% of patients with each of these characteristics show a good outcome, so their inclusion in future routine rtPA protocols is still justified.

Adult↗

PubMed1998

Influence of malignant cell clonogenic capacities and position along the maturation pathway on their susceptibility to lymphokine-activated killer cell cytotoxicity.

In order to investigate the sensitivity of malignant target cells to lysis by LAK cells according to their clonogenic capacities and their position along the maturation pathway, we compared clonogenic and chromium release cytotoxicity assays performed on human hematopoietic cell lines using Effector: Target ratios of 1:1, 3:1, 6:1, 12:1, 24:1, 48:1 and 96:1, and studied the sensitivity of HL-60 and U937 human cell lines after exposure to different factors including GM-CSF, SCF, IFN, Retinoic acid (RA), DMSO, and TPA which are able to recruit cells into the cell cycle or to induce cell differentiation. There was a good correlation between the lysis of the target cells using 51Cr release and the growth inhibition in semisolid medium. The degree of inhibition was significantly higher using the colony growth assay (p = 0.006). Regarding the effects of culturing cell lines with proliferating and differentiating agents on the sensitivity of these cell lines to LAK cytolysis, a correlation was noted between the proliferative response of the U937 cell line and susceptibility to LAK cell lysis (p = 0.01), while results appeared close to significance with HL-60. The most significant effects were a decreased sensitivity of HL-60 to LAK lysis with RA (p < 0.001) and TPA (p < 0.001), and an increased susceptibility of U937 to LAK lysis with GM-CSF (p < 0.0001). In studies planned to investigate whether susceptibility of treated cells to LAK activity was a consequence of a downregulation of adhesion molecules expressed on target cell surface, the proportion of cells expressing adhesion molecules was not significantly changed, except for CD54 expression on HL-60 cells which showed a higher expression, after cells were treated with RA or DMSO. We conclude that clonogenic cells are more sensitive to LAK cell lysis and that cell line sensitivity to LAK cytolysis can be modulated by a variety of agents of potential therapeutic use. The poor correlation between adhesion molecules expression and sensitivity to LAK lysis suggests that molecules other than CD54, CD56, CD58, and CD106 may possibly be more central to the processes involved.

Cell Adhesion Molecules↗

PubMed1998

[The results after 10-16 years of the treatment of chronic anterior laxity of the knee using reconstruction of the anterior cruciate ligament with a patellar tendon graft combined with an external extra-articular reconstruction].

PURPOSE OF THE STUDY: The aim of this prospective study was to evaluate the objective postoperative laxity and functional results with a minimum follow-up of 10 years (mean 11.7 +/- 2 years) in chronic anterior knee instability treated by ACL reconstruction associated to a lateral extra-articular plasty. MATERIAL AND METHODS: 138 patients of a mean age of 27.8 +/- 8.5 years had been operated. Delay between injury and operation was 4 +/- 4.8 years. The surgical "Mac Injones" procedure used a free autologous patellar tendon graft with a bone-to-bone fixation, supplemented by a lateral extra-articular plasty using a strip of quadriceps tendon as a direct prolongation of the graft of the patellar tendon and patella itself. A rehabilitation program aimed to an early recovery of a complete range of motion. Anterior laxity had been measured before and after operation using two instrumented methods, KT-1000 and stress-radiography (at 20 degrees of flexion with a 9 kg load applied at the distal part of the thigh) with measurements of the displacement in medial and lateral compartments. Tunnel positioning was appreciated radiologically. Function was evaluated using the International Knee Documentation Committee score (I.K.D.C.). RESULTS: Elongation of the reconstructed ligament occurred mainly during the first 6 month, but was independent from early full range of motion recovery. Laxity was stabilized after one year. The final laxity gain of the medial compartment was 62 per cent and for the lateral compartment 77 per cent. The pivot shift test was negative in 66 per cent, grade 2 in 4 per cent, grade 1 in 30 per cent. Functional results were excellent and good (A and B) in 60.4 per cent and 76.7 per cent returned to sports activity. 12 reconstructed ligaments reruptured. Arthritis was the cause of poor results in other cases (13.8 per cent). DISCUSSION: Lateral extra-articular plasty is unable to better control translation of the medial compartment than isolated anterior cruciate ligament reconstruction, but laxity of the lateral compartment was minimized and the pivot shift test also. Incorrect position of the anterior cruciate ligament was correlated with poor results. CONCLUSION: This documented study on laxity of the two compartments confirms the interest of each type of reconstruction, in particular extra-articular plasty when made with quadriceps tendon and so doing, preserving the iliotibial-band for the control of varus stability.

Adolescent↗

PubMed1998

[Sarcoma of the pulmonary artery].

Two cases of pulmonary artery angiosarcomas are reported. Pulmonary artery tumor was diagnosed during exploratory thoracotomy in the first case. It was suspected on magnetic resonance imaging and confirmed by surgery in the second case. The therapeutic was a right pneumonectomy for the first patient and a tumor resection followed by chemotherapy and radiotherapy on cerebral metastases for the second patient. Both our patients died, 13 and 44 months after surgery. On the basis of histological and immunohistochemical findings both tumors were angiosarcomas. Ultrastructural examination in the second case revealed an endothelial differentiation. The review of 142 previously reported cases of pulmonary artery sarcomas and these ultrastructural findings suggest that pulmonary artery sarcomas may have multiple origins; leiomyosarcomas deriving from arterial smooth muscle; angiosarcomas deriving from the endothelium and undifferentiated sarcomas or "myointimal sarcomas" deriving from myointimal cells.

Brain Neoplasms↗

PubMed1997

Buspirone, a 5-hydroxytryptamine1A agonist, is active in cerebellar ataxia. Results of a double-blind drug placebo study in patients with cerebellar cortical atrophy.

OBJECTIVE: To establish the antiataxic effect of buspirone hydrochloride, a serotonergic 5-hydroxytryptamine1A (5-HT1A) agonist, in a homogenous group of patients characterized by the same well-defined single condition, cerebellar cortical atrophy. SETTING: University ataxia research center. METHODS: Double-blind randomized study of buspirone vs placebo during a 4-month period. PATIENTS: Nineteen patients met the inclusion criteria; all completed the study. Of these 19 patients, 9 were treated with placebo and 10 were treated with the drug. MAIN OUTCOME MEASURES: A semiquantitative scale for kinetic and static ("postural") cerebellar functions; quantitative clinical measurements measuring time in standard tests that evaluated stance, speech, writing, and drawing; and posturographic analysis of the sway path and sway area of the center-of-foot pressure. The primary end point was improvement of the posttherapeutic change of one of the semiquantitative ataxic scores. The secondary end points were modification of the changes of quantitative measures--clinical or posturographic. RESULTS: In intention-to-treat analysis, a significant improvement of the primary end point, ie, the posttherapeutic change of the ataxic kinetic score, was shown. Among secondary end points, the maximum time of standing with feet together also was significantly improved. CONCLUSIONS: Buspirone is active in cerebellar ataxia of patients with cerebellar atrophy. These results confirm the data suggested by open-label studies with buspirone. However, the effect is partial and not clinically major. These pharmacological results might be due to serotonergic mechanisms and confirm a possible link between cerebellar ataxia and the metabolism of serotonin.

Adult↗

PubMed1997

Activation of a distributed somatosensory cortical network in the human brain. A dipole modelling study of magnetic fields evoked by median nerve stimulation. Part I: Location and activation timing of SEF sources.

Cortical areas responsive to somatosensory inputs were assessed by recording somatosensory evoked magnetic fields (SEF) to electrical stimulation of the left median nerve at wrist, using a 122-SQUID neuromagnetometer in various conditions of stimulus rate, attentional demand and detection task. Source modelling combined with magnetic resonance imaging (MRI) allowed localisation of six SEF sources on the outer aspect of the hemispheres located respectively: (1) in the posterior bank of the rolandic fissure (area SI), the upper bank of the sylvian fissure (parietal opercular area SII) and the banks of the intraparietal fissure contralateral to stimulation, (2) in the SII area ipsilateral to stimulation and (3) in the mid-frontal or inferior frontal gyri on both sides. All source areas were found to be simultaneously active at 70-140 ms after the stimulus, the SI source was the only one active already at 20-60 ms. The observed activation timing suggests that somatosensory input from SI is processed to higher-order areas through serial feedforward projections. However the long-lasting activations of all sources and their overlap in time is also compatible with a top-down control mediated via backward projections.

Adult↗

PubMed1997

Activation of a distributed somatosensory cortical network in the human brain: a dipole modelling study of magnetic fields evoked by median nerve stimulation. Part II: Effects of stimulus rate, attention and stimulus detection.

In this study we used a repeated measures design and univariate analysis of variance to study the respective effects of ISI, spatial attention and stimulus detection on the strengths of the sources previously identified by modelling SEFs during the 200 ms following mentally counted left median nerve stimuli delivered at long and random ISIs (Part I). We compared the SEF source strengths in response to frequent and rare stimuli, both in detection and ignoring conditions. This permitted us to establish a hierarchy in the effects of ISI, attention and stimulus detection on the activation of the cortical network of SEF sources distributed in SI and posterior parietal cortex contralateral to stimulation, and in the parietal operculum (SII) and premotor frontal cortex of both hemispheres. In all experimental conditions the SI and parietal opercular sources were the most active. All sources were more active in response to stimuli delivered at long and random ISIs and the frontal sources were activated only in this condition of stimulation. Driving the subject's attention toward the side stimulated had no detectable effect on the activity of SEF sources at short ISI. At long ISIs mental counting of the stimuli increased the responses of all sources except SI. These results suggest that activation of frontal sources during mental counting could reflect a working memory process, and that of posterior parietal sources a spatial attention effect detectable only at long ISIs.

Adult↗

PubMed1997

Assessment of cerebrovascular reactivity by dynamic susceptibility contrast-enhanced MR imaging.

In patients with cerebrovascular disease the acetazolamide (ACZ) test is performed to evaluate the decrease in cerebral perfusion pressure (CPP) through the investigation of the vasomotor reactivity (VMR). This latter is currently assessed with ACZ with several methods. Recently, magnetic resonance imaging (MRI) techniques have been developed that are sensitive to stimulus-induced changes in blood flow. Dynamic susceptibility contrast material-enhanced gradient-echo MRI techniques (DSC-MRI) might be an attractive tool to assess VMR. We aimed to test the ability of DSC-MRI in the assessment of VMR. Relative hemodynamic parameters rCBV, MTT, and rCBF were evaluated at baseline after the first injection of gadopentetate dimeglumine and 10 min after the intravenous administration of ACZ (1 g) with a second bolus of contrast agent. Assessment of hemodynamic parameters was performed over the whole hemisphere and also within regions of interest. The significances of the mean differences, before and after ACZ, were assessed with repeated-measures ANOVA with two within factors: laterality (right-left) and ACZ. DSC-MRI with ACZ test was performed in ten healthy controls (aged 51.4+/-16.2 years). The cerebral hemispheric ratio for the three parameters (cerebral blood volume (CBV), mean transit time (MTT), and cerebral blood flow (CBF)) ranged between 1.01 and 1.03. The mean gray matter-to-white matter ratio for CBV, CBF and MTT were 2.44, 2.41 and 1.05, respectively. As the laterality effect was not significant, left and right hemispheric values were averaged. A significant increase of all hemodynamic parameters was observed after ACZ (P<0.01-0.001). The same changes for CBV, CBF and MTT were observed after ACZ according to the regions of interest (P<0.006-0.015). DSC-MRI is a non-invasive method which enables the assessment of VMR. This technique may be added to any conventional MRI in order to detect a hemodynamic impact of an ICA stenosis. Therefore, it might be useful in determining the appropriate management when the indication for surgical versus medical therapy is in question.

Acetazolamide↗

PubMed1997

Buspirone, a serotonergic 5-HT1A agonist, is active in cerebellar ataxia. A new fact in favor of the serotonergic theory of ataxia.

We have previously proposed a serotonergic hypothesis for cerebellar ataxia and mentioned that the levorotatory form of 5-hydroxytryptophan, a serotonin precursor, is partially active in subtypes of cerebellar ataxia, including cerebellar cortical atrophy (CCA). It has been demonstrated that 5-HT1A serotonergic receptors play an important role in the control of Purkinje cells discharges and in the inhibition of the release of glutamate by cerebellar glutamatergic terminals. To test further the serotonergic hypothesis of cerebellar ataxia, we administered buspirone, a 5-HT1A agonist usable in human medicine, in a randomized double blind drug placebo trial for 4 months. Nineteen patients with CCA were included; nine patients were given placebo and 10 Buspirone, at the mean dose of 0.69 mg/kg. The evaluation of ataxia was based on a static and a kinetic ataxia scale, fully quantitative measures and the evaluation of the sway path and area at posturography. At 4 months, a significant effect of buspirone was observed for drug induced gains of the kinetic score, two items of the static score, and the maximum duration of standing upright with feet together. These results indicate that a novel chemical therapeutic approach is possible for cerebellar ataxia; moreover, they support the existence of a link between cerebellar ataxia and disturbances of the serotonergic cerebellar system, especially a serotonergic deficit.

Anxiety↗

PubMed1997

Granulocyte colony-stimulating factor given in addition to interferon-alpha to mobilize peripheral blood stem cells for autologous transplantation in chronic myeloid leukaemia.

In order to potentially mobilize and harvest the Ph cells observed in most patients with chronic myeloid leukaemia (CML) during interferon-alpha (IF-alpha) therapy, G-CSF (filgrastim), 5 microg/kg/d, was administered subcutaneously together with IF-alpha to 30 CML patients in haematological remission but with various degrees of cytogenetic remission, after IF-alpha therapy. Peripheral blood stem cells (PBSC) were harvested using standard aphereses from day 5 of G-CSF Patients underwent one to four (median three) aphereses. Median total yields/kg were 7.6 (range 3.8-25) x 10(8) MNC, 3.4 (0-140) x 10(6) CD34+ cells, and 17 (1.1-107) x 10(4) CFU-GM. No patient had a significant increase in the percentage of Ph+ cells in the bone marrow under G-CSF therapy. The percentage of Ph+ cells in apheresis products tended to decrease between the first and the last apheresis (P = 0.05). 14 patients who were not responsive to IF-alpha were transplanted after conditioning with busulphan 16 mg/kg and melphalan 140 mg/m2. Median time to neutrophils > 0.5 x 10(9)/l was 20 d (16-114 d) and to platelets > 50 x 10(9)/l 18 d (12-149 d). Nine patients had a major cytogenetic response post graft, which correlated with the amount of Ph+ cells reinfused with the graft (P = 0.02). We conclude that this procedure is feasible, allowing the harvest of enough PBSC, some of them Ph- in patients who responded to IF-alpha, to allow autologous transplantation.

Adult↗