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M Deschênes

Publications and source records attributed to M Deschênes.

At least 19 recordsLinked to original sources
PubMed2004

[Rapid antigen detection tests for diagnosis of group A streptococcal pharyngitis: comparative evaluation of sensitivity and practicability of 16 in vitro diagnostics medical devices performed in July 2002 by the French health products safety agency (Afssaps) as part of its market control mission].

Within the scope of its health products control mission, the French Health Products Safety Agency (Afssaps) collaborating with two expert's sites, has assessed the 16 tests available on the French market in 2002 for rapid diagnosis of the Streptococcus A tonsillitis. The purpose of this study was to verify the reliability and rapidity of these tests and to give some information to the users about their analytical criteria and practicability characteristics. The analytical study has been performed on a same panel of four reference strains of Streptococcus pyogenes dilutions to determine the limit of detection of all the reagents in the same condition of methodology. The limit of detection has been calculated with the results expressed in colony forming unit by ml (CFU/ml). The practicability study has permitted to analyze the quality of the presentation, the easiness of the final reading and of performing tests. A score has been established for each rapid test. A classification of the analytical sensitivity (limit of detection) and practicability (score) of these 16 devices has been established. The limit of detection of the reagents giving the best results allows the detection of the lowest bacterial concentration of the panel which is 10(5) CFU/ml. Regarding practicability, the results suggest that, the immunochromatographic strip methods have the best score in a view with the use by a non medical laboratory.

Antigens, Bacterial↗
PubMed2003

Efficacy of mycophenolate mofetil combined with very low-dose cyclosporine microemulsion in long-term liver-transplant patients with renal dysfunction.

BACKGROUND: Cyclosporine (CsA)-induced renal dysfunction is common after liver transplantation. We evaluated the efficacy of tapering CsA to a very low dose and introducing mycophenolate mofetil (MMF) in long-term liver-transplant recipients with renal dysfunction. In addition, we assessed the impact of this strategy on calcineurin inhibition and on transforming growth factor (TGF)-beta levels. METHODS: We prospectively enrolled 19 adult, long-term (>1 year) liver-transplant recipients with a decreased creatinine clearance greater than 25% compared with the first month posttransplant. MMF was introduced, and CsA was tapered to 25 mg twice daily. Calcineurin inhibition and TGF-beta were measured at baseline and 3 months thereafter. RESULTS: The CsA dose was tapered over 13+/-3 weeks. At 1-year follow-up, serum creatinine decreased from 141+/-24 to 105+/-22 micromol/L (P=0.002), creatinine clearance increased from 53+/-9 to 71+/-19 ml/min (P=0.02), and glomerular filtration rate increased from 40+/-13 to 64+/-18 mL/min (P=0.002). The incidence of acute rejection was 29%. Antihypertensive medications were discontinued in 71% of the patients. Although CsA levels decreased significantly, serum TGF-beta did not differ from normal controls, and calcineurin inhibition remained stable. The incidence of gastrointestinal side-effects and leukopenia was 18% and 24%, respectively. CONCLUSION: In long-term liver-transplant recipients with renal dysfunction, the introduction of MMF followed by tapering of CsA to a very low dose resulted in a significant improvement in renal function. However, this strategy maybe associated with a risk of acute rejection. The clinical pertinence of measuring serum TGF-beta levels and calcineurin inhibition remains to be determined.

Creatinine↗
PubMed2003

Do biliary endoprostheses decrease biliary complications after liver transplantation?

AIM: Most technical complications after orthotopic liver transplantation (OLT) are related to the biliary tree. This report reviews the role of routine intraoperative placement of stents to reduce biliary complications. METHODS: We retrospectively analyzed 396 consecutive OLTs. We reviewed rates of biliary complications after hepaticojejunostomy (HJA) as well as following choledochocholedochostomy (CCA) groups: "experimental" group (routine intraoperative biliary stenting, last 10 months), "recent" control group (nonstented, previous 10 months), "historical" control group (prior to that period of time). RESULTS: All groups were matched for donor/recipient characteristics and for graft cold/warm ischemia time. The overall prevalence of biliary complications was 30.7% after CCA versus 35% after HJA. In the experimental group 21 patients had a 4.8% biliary complication rate compared to the recent control and historical groups, where biliary complication rates were 30% and 32.6%, respectively (P <.05). CONCLUSIONS: The intraoperative use of biliary stents is feasible and appears to decrease the rate of biliary complications. These results support the need for a prospective randomized trial.

Choledochostomy↗
PubMed2001

Elevation of CA-125 level is due to abdominal distension in liver transplantation candidates.

BACKGROUND: CA (cancer antigen) 125 is a serologic marker used in the monitoring of ovarian cancer. Elevated levels are also reported in cirrhosis. We evaluated the range of serum CA 125 levels seen before and after liver transplantation, and examined possible factors associated with CA 125 elevation. METHODS: We examined prospectively 57 consecutive patients with cirrhosis who underwent liver transplantation. CA 125 levels were also measured in two patients with polycystic liver disease. RESULTS: The mean serum CA 125 level before transplantation was 352+/-549 u/ml, compared with 46+/-49 u/ml after transplantation (P<0.001). Multivariate analysis identified the degree of ascites as the only significant predictive variable of preoperative CA 125 level. In five patients who underwent abdominal paracentesis, the mean ascites CA 125 level (951+/-322 u/ml) was higher than that of the serum (619+/-290 u/ml) (P<0.003). In 16 hepatectomy specimens, the grade of staining for CA 125 was 0.8+/-1.4 for the mesothelium of patients with a normal serum CA 125 level, compared with 1.5+/-1.1 in patients with elevated serum levels (P=0.37). Two patients with severe abdominal distension due to polycystic liver disease but without ascites had elevated serum CA 125 levels. DISCUSSION: CA 125 concentration is elevated in the majority of patients with cirrhosis and normalizes after liver transplantation. It is a reflection of the abdominal distention seen in these patients. Therefore, an elevation in CA 125 should not be considered a contraindication to liver transplantation in the absence of evidence of malignancy.

Ascites↗
PubMed2001

Relationship between pre-TIPS liver perfusion by the portal vein and the incidence of post-TIPS chronic hepatic encephalopathy.

OBJECTIVE: In the present study we evaluated the predictive value of pretransjugular intrahepatic portosystemic shunt (TIPS) portal perfusion as assessed by Doppler ultrasonography for the onset of chronic encephalopathy after TIPS. METHODS: A total of 231 cirrhotic patients were followed-up prospectively after TIPS placement. The pattern of intrahepatic portal flow was assessed before TIPS. Patients were divided into two groups according to Doppler findings. Group 1 comprised patients with prograde portal flow (n = 200), whereas group 2 comprised those with loss of portal perfusion (hepatofugal or back-and-forth flow or portal vein thrombosis; n = 31). The presence of chronic encephalopathy during a median follow-up of 32 months was prospectively recorded. The prognostic value of the following parameters for the onset of chronic recurrent encephalopathy after TIPS was evaluated: age, presence of encephalopathy before TIPS, alcoholism, Pugh score, and loss of portal perfusion before TIPS. The independent prognostic value of each variable was tested with a multiple logistic regression analysis. RESULTS: The two groups were comparable in terms of age, incidence of prior episodes of hepatic encephalopathy, and portacaval gradient before and after the procedure; however, liver failure was more severe in patients in group 2 (Pugh score: 9.2 +/- 1.9 vs 10.3 +/- 1.7). The 3-yr survival was identical for both groups; 25% of the 200 patients in group 1 developed chronic encephalopathy as compared to 6% of the 31 patients in group 2 (p = 0.03). Multiple logistic regression analysis demonstrated that loss of portal perfusion and age >65 yr were the only independent predictors of the onset of post-TIPS chronic encephalopathy (odds ratios 0.24 and 1.98, respectively). CONCLUSIONS: Cirrhotic patients with loss of portal perfusion before TIPS were protected against post-TIPS chronic hepatic encephalopathy despite a more severe liver dysfunction at baseline. The only other independent predictive factor for the onset of this complication was age.

Adult↗
PubMed2001

Transjugular intrahepatic portosystemic shunt (TIPS) versus endoscopic variceal ligation in the prevention of variceal rebleeding in patients with cirrhosis: a randomised trial.

BACKGROUND AND AIMS: The transjugular intrahepatic portosystemic shunt (TIPS) is a new therapeutic modality for variceal bleeding. In this study we compared the two year survival and rebleeding rates in cirrhotic patients treated by either variceal band ligation or TIPS for variceal bleeding. METHODS: Eighty cirrhotic patients (Pugh score 7-12) with variceal bleeding were randomly allocated to TIPS (n=41) or ligation (n=39), 24 hours after control of bleeding. RESULTS: Mean follow up was 581 days in the ligation group and 678 days in the TIPS group. The two year survival rate was 57% in the TIPS group and 56% in the ligation group (NS); the incidence of variceal rebleeding after two years was 18% in the TIPS group and 66% in the ligation group (p<0.001). Uncontrolled rebleeding occurred in 11 patients in the ligation group (eight were rescued by emergency TIPS) but in none of the TIPS group. The incidence of encephalopathy at two years was 47% in the TIPS group and 44% in the ligation group (NS). CONCLUSIONS: TIPS did not increase the two year survival rate compared with variceal band ligation after variceal bleeding in cirrhotic patients with moderate or severe liver failure. It significantly reduced the incidence of variceal rebleeding without increasing the rate of encephalopathy.

Adolescent↗
PubMed2000

Parallel streams for the relay of vibrissal information through thalamic barreloids.

This study investigated the organization of a vibrissal pathway that arises from the interpolar division of the spinal trigeminal complex (SP5i), transits through the ventral posterior medial nucleus (VPM), and innervates the somatosensory cortical areas in the rat. Using Fluoro-Gold and biotinylated dextran amine, respectively, as retrograde and anterograde tracers, the following organization plan was disclosed. The SP5i projection arises from a population of small-sized neurons that selectively innervate the ventral lateral part of VPM. In cytochrome oxidase-stained material, this region does not display any barreloid arrangement, but Fluoro-Gold injections in single barrel columns labeled rods of cells that extend caudally into the ventral lateral division of VPM. Thus, on the basis of retrograde labeling, barreloids were divided into core and tail compartments, which correspond to the rod segments running across the dorsal and ventral lateral parts of VPM, respectively. Double-labeling experiments revealed that SP5i afferents innervate the tail of barreloids. The anterograde labeling of thalamocortical axons show that most "core cells" project to a single barrel column, whereas some "tail cells" give rise to branching axons that innervate the second somatosensory area and the dysgranular zone of the barrel field. Injections that straddled the transition zone between the core and tail regions disclosed cells projecting to a single barrel column and to the surrounding dysgranular zone. These results suggest that the projection of "barreloids cells" to the granular and/or dysgranular zones relates to the class of prethalamic input(s) they receive.

Afferent Pathways↗
PubMed2000

Corticothalamic projections from layer 5 of the vibrissal barrel cortex in the rat.

This study bears on the projections of layer 5 cells of the vibrissal sensory cortex to the somatosensory thalamus in rats. Small groups of cells were labeled with biotinylated dextran amine (BDA), and their axonal arborizations were individually reconstructed from horizontal sections counterstained for cytochrome oxidase. Results show that the vast majority ( approximately 95%) of layer 5 axons that innervate the somatosensory thalamus are collaterals of corticofugal fibers that project to the brainstem. The anterior pretectal nucleus, the deep layers of the superior colliculus, and the pontine nuclei are among the structures most often coinnervated. In the thalamus, layer 5 axons terminate exclusively in the dorsal part of the posterior group (Po), where they form clusters of large terminations. Because dorsal Po projects to multiple cortical areas, we sought to determine whether all recipient areas return a layer 5 projection to this part of the thalamus. Additional experiments using fluoro-gold and BDA injections provided evidence that the primary somatosensory area is the sole source of layer 5 projections to dorsal Po but that this thalamic region receives convergent layer 6 projections from the primary and second somatosensory areas and from the motor and insular cortices. These results show that layer 5 projections do not overlap in associative thalamic nuclei, thus defining area-related subdivisions. Furthermore, the coinnervation of brainstem nuclei by layer 5 CT axons suggests that this pathway conveys to the thalamus a copy of the cortical output aimed at brainstem structures.

Animals↗
PubMed2000

Thalamic projections from the whisker-sensitive regions of the spinal trigeminal complex in the rat.

This study investigated the axonal projections of whisker-sensitive cells of the spinal trigeminal subnuclei (SP5) in rat oral, interpolar, and caudal divisions (SP5o, SP5i, and SP5c, respectively). The labeling of small groups of trigeminothalamic axons with biotinylated dextran amine disclosed the following classes of axons. 1) Few SP5o cells project to the thalamus: They innervate the caudal part of the posterior group (Po) and the region intercalated between the anterior pretectal and the medial geniculate nuclei. These fibers also branch profusely in the tectum. 2) Two types of ascending fibers arise from SP5i: Type I fibers are thick and distribute to the Po and to other regions of the midbrain, i.e., the prerubral field, the deep layers of the superior colliculus, the anterior pretectal nucleus, and the ventral part of the zona incerta. Type II fibers are thin; branch sparsely in the tectum; and form small-sized, bushy arbors in the ventral posterior medial nucleus (VPM). Accordingly, a statistical analysis of the distribution of antidromic invasion latencies of 96 SP5i cells to thalamic stimulation disclosed two populations of neurons: fast-conducting cells, which invaded at a mean latency of 1.23 +/- 0. 62 msec, and slow-conducting cells, which invaded at a mean latency of 2.97 +/- 0.62 msec. 3) The rostral part of SP5c contains cells with thalamic projections similar to that of type II SP5i neurons, whereas the caudal part did not label thalamic fibers in this study. A comparison of SP5i projections and PR5 projections in the VPM revealed that the former are restricted to ventral-lateral tier of the nucleus, whereas the latter terminate principally in the upper two tiers of the VPM. These results suggest a functional compartmentation of thalamic barreloids that is defined by the topographic distribution of PR5 and type II SP5i afferents.

Animals↗
PubMed1999

Single- and multi-whisker channels in the ascending projections from the principal trigeminal nucleus in the rat.

This study investigated the relationship between axonal projections and receptive field properties of whisker-sensitive cells in the principal trigeminal sensory nucleus of the rat. The labeling of small groups of trigeminothalamic axons with biotinylated dextran amine disclosed two broad classes of axons; a majority of fibers (68%; n = 107) project to a single barreloid of the ventral posteromedial nucleus, and the remaining group includes axons that innervate both the posterior group of the thalamus and the tectum. Additional terminal sites for axons of this latter group may include the pretectum, the zona incerta, the medial part of the medial geniculate nucleus, and the ventral posteromedial nucleus. Corresponding to these two classes of fibers, 67% of the cells in the principal trigeminal nucleus (n = 313) have single-whisker receptive fields, whereas the rest of the population have receptive fields composed of multiple whiskers. The tonic or phasic properties of the responses apparently bear no relation to the axonal projection patterns. Solid retrograde labeling of cells that project to the ventral posteromedial nucleus and intracellular staining revealed that single-whisker cells have small somata and narrow, barrelette-bounded dendritic trees. In contrast, multi-whisker neurons have large multipolar somata, expansive dendritic trees, and many respond antidromically to stimulation of the superior colliculus. Together, these results provide evidence for two main channels of vibrissal information: a single-whisker channel that links trigeminal barrelettes to their corresponding barreloids, and a multi-whisker channel that distributes principally in the posterior group and tectum.

Animals↗
PubMed1999

Use of older donor livers is associated with more extensive ischemic damage on intraoperative biopsies during liver transplantation.

Initial poor graft function is associated with increased morbidity and graft loss after liver transplantation. Donor age is a risk factor for the development of initial poor function. The severity of ischemic damage on intraoperative postreperfusion (0Post) allograft biopsy specimens is predictive of subsequent initial poor function. This study was performed to assess whether donor age is a risk factor for the development of ischemic damage on 0Post biopsy specimens. The records of 94 liver transplantations were reviewed. 0Post biopsy specimens were obtained after complete allograft revascularization. The severity of ischemic damage was graded as follows: 0, none; 1, minimal; 2, mild; 3, moderate; and 4, severe. Grafts were defined as older when donor age was 50 years or older. Other independent variables examined included donor cause of death, length of hospital stay, acidosis, serum alanine aminotransferase level, graft cold ischemia time, and degree of steatosis. Older grafts were associated with higher grades of ischemic damage than younger grafts (2.3 +/- 1.0 v 1.3 +/- 1.1; P =.003). Univariate and multivariate analysis identified donor age of 50 years or older as the only significant predictive variable of the severity of ischemic damage. In 16 transplantations involving older grafts, there was no statistically significant association between the severity of ischemic damage and incidence of initial poor function and graft loss. The use of older liver grafts is associated with more extensive ischemic damage immediately after graft reperfusion. Whether this early lesion identifies among older graft recipients those at risk for a worst outcome remains to be determined.

Adult↗
PubMed1999

Hepatitis C virus is related to progressive liver disease in human immunodeficiency virus-positive hemophiliacs and should be treated as an opportunistic infection.

The hypothesis was investigated that hepatitis C virus (HCV) infection behaves like an opportunistic infection in which progressive liver disease (PLD) is the principal manifestation. PLD in 81 hemophiliacs coinfected with HCV and human immunodeficiency virus (HIV) was compared with 53 HIV-seronegative HCV-infected hemophiliacs. Progression to AIDS and death in 22 HCV/HIV-coinfected hemophiliacs with PLD was also compared with 59 coinfected hemophiliacs who did not develop PLD. The risk of PLD occurrence associated with an HIV-positive status was 7.4 (95% confidence interval [CI], 2.2-25.5; Cox model). In the coinfected group, the risk of PLD occurrence was higher in subjects with severe AIDS-defining immunodeficiency than in those without (odds ratio, 3. 6; 95% CI, 1.3-10). Persons with PLD also had a faster progression to AIDS (P=.03, log rank test) than those without PLD. Thus, as with other chronic resident human viruses, HCV should be considered another opportunistic pathogen in HIV disease.

AIDS-Related Opportunistic Infections↗
PubMed1999

Predictors of clinical response to transjugular intrahepatic portosystemic shunt (TIPS) in cirrhotic patients with refractory ascites.

OBJECTIVE: Transjugular intrahepatic portosystemic shunt (TIPS) is used increasingly as a treatment for refractory ascites. The aim of the present study was to determine the prognostic value of different parameters in predicting a favorable evolution following TIPS in a cohort of 53 cirrhotic patients without organic renal disease and with refractory ascites. METHODS: Patients were classified as good responders if they survived more than 6 months, without severe chronic hepatic encephalopathy and with good control of ascites. The prognostic value for a good outcome was evaluated using age, creatinine clearance, plasma renin activity, plasma aldosterone, and Pugh score. RESULTS: Good control of ascites was obtained in 90%. The cumulative survival rate was 54% at 6 months, 48% at 1 yr, and 39% at 2 yr. The vast majority of patients died of complications of hepatic insufficiency. Severe chronic hepatic encephalopathy developed in 26%. Overall, a good clinical response was observed in 47%. Creatinine clearance was identified as the only pre-TIPS factor to be significantly and independently associated with a good clinical response to TIPS for refractory ascites. A good clinical response was observed in 57% of patients with a creatinine clearance >36 ml/min compared to 9% of those with a clearance <36 ml/min (p < 0.01). This cutoff point in creatinine clearance had a sensitivity of 96% and a specificity of 36%; positive predictive and negative predictive values were 57% and 90%, respectively. CONCLUSIONS: TIPS might be useful for the treatment of refractory ascites in cirrhotic patients without severe renal function impairment. However, the TIPS usefulness still has to be demonstrated compared to large volume paracentesis or Leveen shunt. In patients with poor renal function or with liver failure after TIPS, liver transplantation should be considered.

Adult↗