Laser oscillation with low quantum defect in Yb:GdVO4, a crystal with high thermal conductivity

A Yb:GdVO4 single crystal was grown by the Czochralski process. Its thermal conductivity was measured by photothermal analysis and reached 8.1 and 7.1 W m(-1) K(-1) along and perpendicular to the c axis, respectively. These values are in good agreement with the predicted ones. The optical spectroscopy of the crystal, such as its absorption and emission cross sections under the two polarizations, its fluorescence lifetime, and its laser parameters, is investigated. Cw laser oscillation is obtained for what is to our knowledge the first time in this material under titanium sapphire pumping at 984 nm. We obtain 420 mW of output power for a 2% output coupler at 1029 nm. With a thin sample, the laser wavelength decreases to 1015 nm. In this case the quantum defect is as small as 2.9%. The weak heat release of the material suggests good prospects for its use in high-power applications.

Is surgical intervention still indicated in recurrent aortic arch obstruction?

BACKGROUND

Introduction of balloon dilatation has become the standard treatment for recurrent aortic arch obstruction and has changed the therapeutic approach to patients with this disorder.

OBJECTIVES

Whether all patients with recurrent aortic arch obstruction are candidates for balloon dilatation remains unanswered. In addition, only few reports have tried to compare the results between patients undergoing balloon dilatation or redo operations.

METHODS

Since 1983, 97 patients underwent reintervention for recurrent aortic arch obstruction (42 dilations and 55 reoperations). Eight had immediate unsuccessful dilatation and were shifted to the surgical group (n = 63). The median age at reintervention was 21.7 months (10 days-45 years), and the median delay was 13.6 months (7 days-17 years). Anatomy of the aortic arch oriented the surgical approach to treat arch hypoplasia. It could be performed through a left thoracotomy in 52 patients, with extended end-to-end anastomosis in 34 patients, subclavian flap repair in 9 patients, conduit insertion in 6 patients, and patch enlargement in 3 patients. More recently, an anterior approach with cardiopulmonary bypass without circulatory arrest was applied to enlarge the patch in all the aortic arches.

RESULTS

There was one early death in the surgical intervention group and 2 late deaths in the dilation group. Major complications and recurrence were higher in the dilated group (4 vs 0, P <.01, and 14 vs 5, P <.0004, respectively). At a mean follow-up of 11.8 +/- 4.1 years in the surgical intervention group and 7.5 +/- 2.5 years in the dilated group, systemic hypertension was normalized in all but 5 patients in the surgical intervention group and 6 patients in the dilated group.

CONCLUSION

Reoperation for recurrent aortic arch obstruction can be performed safely, with low rates of mortality and morbidity. This approach should be considered versus balloon angioplasty, especially in patients older than 4 years and in the presence of aortic arch hypoplasia.

Autologous stem cell transplantation for primary refractory Hodgkin's disease: results and clinical variables affecting outcome

BACKGROUND

Patients with primary refractory Hodgkin's disease (PR-HD) have a dismal prognosis when treated with conventional salvage chemotherapy. We analyzed time to treatment failure (TTF), overall survival (OS) and clinical variables influencing the outcome in patients undergoing autologous stem cell transplantation (ASCT) for PR-HD and reported to the Grupo Español de Linfomas/Trasplante Autólogo de Médula Osea (GEL/TAMO).

PATIENTS AND METHODS

Sixty-two patients, 41 males and 21 females with a median age of 27 years (range 13-55) were analyzed. Forty-two patients (68%) had advanced stage at diagnosis, 47 (76%) presented with B symptoms and 29 (47%) with a bulky mediastinal mass. Seventy-five percent of the patients had received more than one line of therapy before ASCT. Thirty-three patients received bone marrow as a source of hematopoietic progenitors, and 29 peripheral blood. Six patients were conditioned with high-dose chemotherapy plus total-body irradiation and 56 received chemotherapy-based protocols.

RESULTS

One-year transplantation-related mortality was 14% [95% confidence interval (CI) 6% to 23%]. Response rate at 3 months after ASCT was 52% [complete remission in 21 patients (34%), partial remission in 11 patients (18%)]. Actuarial 5-year TTF and OS were 15% (95% CI 5% to 24%) and 26% (95% CI 13% to 39%), respectively. The presence of B symptoms at ASCT was the only adverse prognostic factor significantly influencing TTF [relative risk (RR) 1.75, 95% CI 0.92-3.35, P = 0.08]. The presence of B symptoms at diagnosis (RR 2.08, 95% CI 0.90-4.79, P = 0.08), MOPP-like regimens as first-line therapy (RR 3.84, 95% CI 1.69-9.09, P = 0.001), bulky disease at ASCT (RR 2.79, 95% CI 0.29-6.03, P = 0.009) and two or more lines of therapy before ASCT (RR 2.24, 95% CI 0.95-5.27, P = 0.06) adversely influenced OS.

CONCLUSIONS

In our experience, although overall results of ASCT in PR-HD patients are poor, one-quarter of the patients remain alive at 5 years. Despite this, other therapeutic strategies should be investigated in this group of patients to improve the outcome.

[Neonatal cardiac transplantation. Long-term results]

The pioneering work of Bailey since 1985 has made cardiac transplantation an effective treatment of left heart hypoplasia in the neonatal period. At the Marie-Lannelongue surgical centre, 5 neonates with hypoplastic left hearts or an equivalent cardiac malformation, underwent cardiac transplantation between 1993 and 1998. There were no operative deaths. At the end of the follow-up, all children were treated with cyclosporine, without steroids. One child died of a secondary acute rejection resistant to treatment 7 years after the transplantation, 1 has a severe coronary problem 13 years after the transplantation, and three children (including the diseased child) have psychomotor development abnormalities. These results and those of the literature together with the psychological problems encountered by the children and their families, do not incite in the pursuit of the neonatal transplantation program until the introduction of new drugs for the treatment of chronic rejection which should prevent the programmed death of these children.

[Pediatric cardiac transplantation. Long-term results and problems]

The aim of this study was to establish an assessment for cardiac transplantation by retrospective analysis of data from two French centres. Screening for acute rejection was ensured by systematic myocardial biopsies for patients aged over 10 years, and by clinical non-invasive follow up, ECG and Doppler echo in the younger ones. Coronaropathy was screened for by coronarography or stress echography. Eighty three cardiac transplantations were performed in 82 patients aged 9.2 +/- 6 years. The follow up was 5.8 +/- 4.8 years. Survival was 86% at 1 month, 76% at 1 year, 73% at 5 years and 60% at 10 years and did not differ for age at transplantation (p = 0.88) or the initial pathology (p = 0.25). Twenty-nine patients died in the period between 3 days to 11 years, of which 13 were during the first month and 9 after one year (of which 4 were acute rejections and 2 coronaropathies). The incidence of acute rejection was 1.8 episodes per patient; 42% were late rejections, through non-compliance for half of them. Systematic biopsy was useful in the first 3 months post transplant. Eight patients (9.6%) presented with coronaropathy of the graft, progressive for 5 of them. Renal function was altered in 12% of cases, especially in the patients transplanted before the age of 2 years. The results of paediatric cardiac transplantation are satisfactory. Acute rejection and therapeutic compliance for adolescents, graft coronaropathy, and renal function of infants remain the principal elements for the long term prognosis.

Central and extrapontine myelinolysis following allogeneic peripheral haematopoietic progenitor cell transplantation. Favourable outcome in a patient with chronic myeloid leukaemia

A 48-year-old-man in the first chronic phase of chronic myeloid leukaemia developed a central nervous system complication on day +57 after HLA-identical peripheral blood progenitor cell (PBPC) transplantation. The clinical picture evolved to a reversible pseudobulbar palsy requiring mechanical ventilation. MRI examination disclosed lesions typical of central and extrapontine myelinolysis (CEPM), which disappeared on a repeat examination 20 days later. The patient had received cyclosporine A (CsA) as GVHD prophylaxis and severe hyponatremia was detected 7 days after the first neurological sign. CEPM has been described in alcohol-induced liver disease, following rapidly corrected hyponatremia and associated with CsA in orthotopic liver transplantation. This is the first reported case of CEPM in PBPC transplantation, and CsA seems to have played a role in the development of this very serious complication.

Application of a Kohonen neural network to the analysis of data regarding the alkylation of toluene with methanol catalyzed by ZSM-5 type zeolites

para-Xylene is widely used in chemical industry. It can be synthesized by alkylation of toluene with methanol using zeolite ZSM-5 as catalyst. The proportion of para-xylene, among its other isomers and other reaction byproducts, depends on the reaction conditions. As this process still remains largely empirical, we attempted to build a theoretical model able to predict the para-xylene yield under specific reaction conditions. We have consequently collected data regarding this reaction from the literature and exploited the potency of a particular artificial neural network (ANN), the counter-propagation ANN based on the Kohonen technique. The results show that such an approach is suitable to establish a predictive model of the yield in para-xylene on the basis of reaction parameters. The quality of the model could be further improved by considering a larger valuable data set, e.g. including experiments characterized by a low yield in para-xylene.

[Atrial septal defects: problems in adults]

The clinical features of atrial septal defects in adults have changed due to the generalisation of surgery of the anomaly in childhood and the widespread use of transoesophageal echocardiography. Rare complications, such as paradoxical embolism or cerebral abscess, can now be more reliably attributed. Pulmonary hypertension, a feared traditional complication, is better understood: the severe form with right-to-left shunting (Eisen-menger's syndrome) occurs rarely in young adults, with a probable genetic predisposition; the less severe form, with persistence of a large left-to-right shunt is observed more often in adults over 50 years of age, and closure of the atrial septal defect remains beneficial over a long period of time. It has now been shown that this repair, even when performed late, improves symptoms but with less effect on atrial arrhythmias. Percutaneous closure is the treatment of choice and surgery is only considered after failure of endocavitary closure. The indication for closure of small atrial septal defects remains the subject of controversy.

[Three-dimensional multislice CT scanner: value in patients with pulmonary atresia with septal defect]

The aim of this study was to evaluate the interest of multislice CT scanning using three-dimensional reconstructions for pre- or postoperative management of patients with pulmonary atresia with ventricular septal defect. Twenty-one consecutive patients (median age: 8 months, median weight: 5.6 kg) with pulmonary atresia with ventricular septal defect were explored by multislice CT. Standard protocol consisted in one helical thoracic acquisition, associated with an injection of 2 to 3 mL/kg of iodinated contrast medium at a flow rate from 0.5 to 1 mL/s. Three-dimensionnal reconstructions were systematically performed. Before operation, status and size of central pulmonary arteries, major aorto-pulmonary collateral arteries, and associated anomalies were analyzed. In 13 operated patients, the permeability of palliative anastomosis and postoperative anatomical changes were studied. The status of central pulmonary arteries was assessed in all cases and the sizes found were in agreement to surgical findings. Main aorto-pulmonary collateral arteries were depicted and their relative position to central airways was assessed. Various associated anomalies were found: right aortic arch, anomalous coronary artery, abnormal pulmonary venous return, left superior vena cava. The anastomosis and the surgical connections (unifocalization, complete repair) were clearly analyzed. The multislice CT with three-dimensional reconstructions is a complementary imaging technique, reliable, useful to pre-operative management and postoperative follow-up of patients with pulmonary atresia with ventricular septal defect.

CsA-based post-graft immunosuppression: the main factor for improving outcome of allografted patients with acquired aplastic anemia. A retrospective survey by the Spanish Group of Hematopoietic Transplantation

A retrospective multicenter study was performed to assess the clinical results in patients with acquired aplastic anemia (AA) allografted over a 19 year period and to identify prognostic factors influencing survival. From April 1978 to December 1997, 176 patients were transplanted. Records from 160 receiving related matched bone marrow transplantation (BMT) were reviewed. Fifty-two percent of the patients were older than 20 years, 5% older than 40; 6.3% were untransfused at BMT and 56.2% had received prior treatments. Conditioning regimens were with chemotherapy in 43.7% of the procedures and with additional irradiation in 56.3%. Graft-versus-host disease (GVHD) prophylaxis was based on cyclosporin A (CsA) in 58.1% of the patients while methotrexate (MTX) was administered to 41.9%. Transplantation earlier on, a longer interval from diagnosis to BMT, GVHD prophylaxis with MTX, graft failure/rejection and acute severe GVHD were adverse factors for survival. The use of CsA emerged as the main factor for the improvement, inducing a significant decrease in graft failure/rejection rate and severe acute GVHD when compared with MTX alone. Radiation-containing regimens decreased the graft failure/rejection rate without improving survival due to the increased risk of acute GVHD. Age and number of transfusions pretransplant did not influence outcome. Survival achieved since 1991 is 79.79%, and graft failure and acute severe GVHD rates are 6.0% and 11.8%, respectively. In conclusion, CsA-based post-graft immunosuppression has been crucial in achieving improved survival in patients with acquired AA up to 40 years of age. Regardless of CsA use, further improvement in survival was apparent with time, probably due to better skills in patient care.

Importance of radiotherapy in the outcome of patients with primary CNS lymphoma: an analysis of the CHOD/BVAM regimen followed by two different radiotherapy treatments

PURPOSE

To assess the effect of a reduced dose of radiotherapy (RT) in patients with primary CNS lymphoma (PCNSL) responding to the cyclophosphamide, doxorubicin, vincristine, and dexamethasone (CHOD)/carmustine, vincristine, methotrexate, and cytarabine (BVAM) regimen.

PATIENTS AND METHODS

Patients received one cycle of CHOD and two of BVAM. In the first trial, all 31 patients received 45-Gy whole-brain RT (CHOD/BVAM I). In the second, with 26 patients, RT dose was reduced to 30.6 Gy if there was a complete response (CR) after chemotherapy (CHOD/BVAM II).

RESULTS

Age, performance status, and chemotherapy received were similar in both protocols. CR rate at the end of all treatment was 68% for CHOD/BVAM I and 77% and for CHOD/BVAM II. Treatment modality was the only predictor of relapse, with 3-year relapse risks of 29% and 70% for CHOD/BVAM I and II, respectively. This was specifically important in the 25 patients less than 60 years old (3-year relapse risk, 25% v 83%; P =.01). The 5-year overall survival (OS) was 36%. Age (< 60 v > or = 60 years) was the only predictor for OS in the multivariate analysis (relative risk, 2.1; 95% confidence interval, 1.4 to 2.8). RT dose was the only predictor of OS in patients younger than 60 years old who achieved CR at the end of all treatment (3-year OS, 92% v 60% for patients receiving 45 or 30.6 Gy, respectively; P =.04).

CONCLUSION

Reduction of the RT dose from 45 Gy to 30.6 Gy in patients younger than 60 years old with PCNSL who achieved CR resulted in an increased risk of relapse and lower OS.

Waldenström macroglobulinaemia: presenting features and outcome in a series with 217 cases

In this report we analyse the presenting features of a series of patients diagnosed with Waldenström macroglobulinaemia (WM) in Spain over the last 10 years. Criteria for diagnosis required a serum monoclonal IgM protein > or = 30 g/l and > 20% bone marrow lymphocytes. Two hundred and seventeen patients were included in the study, with a median age of 69 years and male/female ratio of 2:1. The most common symptoms at diagnosis were anaemia (38%), hyperviscosity (31%), B symptoms (23%), bleeding (23%) and neurological symptoms (22%). Sixty-one patients (27%) were asymptomatic at diagnosis and, to date, 32 of them have not received chemotherapy. Variables predicting a shorter survival free of therapy were haemoglobin < 12.5 g/dl and high beta2microglobulin (beta2M). The 83% of patients who did receive treatment were distributed as follows: chlorambucil/prednisone (43%), intermittent chlorambucil (11%), continuous chlorambucil (26%), cyclophosphamide/vincristine/prednisone (COP, 13.5%) and other (6.5%). Response to therapy was complete in 2%, partial in 48% and minor in 10%. Finally, 28% and 13% of patients presented stable and progressive disease, respectively, which was more common among patients treated with COP. Progression-free survival was 43% at 5 years, with three independent predictors for shorter progression-free survival (PFS): COP treatment, age > 65 and B symptoms at diagnosis. The 10-year projected overall survival (OS) was 55%. The two most frequent causes of death were development of second malignancies (31%), or infections (19%). The two main variables predicting a poor OS were hyperviscosity and high beta2M. In summary, this study favours the use of chlorambucil-based therapy as the standard treatment for WM, and describes a subset of patients who should be considered as suffering a smouldering form and who therefore do not require treatment for a long period of time.

[Percutaneous closure of ostium secundum atrial septal defect using an Amplazter device. Report of the first 5 Tunisian cases]

We report our initial expérience with percutaneous closure of ostium secundum atrial septal defect using Amplatzer device. Between september 2000 and july 2001, five devices were implanted in 5 patients, 4 female and 1 male. Age ranged from 18 to 66 years. A large atrial septal defect with significant shunting was diagnosed by trans thoracic echocardiography. Procedures were performed under general anesthesia with trans esophageal echocardiography guidance. Stretched diameter of atrial septal defects was determined by balloon sizing, ranged from 21 to 32 mm. Amplatzer devices of 20 to 32 mm were respectively deployed. No complications occurred during the procedure. Total occlusion of interatrial communication, was observed in one patient, immediately after the procedure, and in 3 patients 24 hours later. First 3 patients were controlled at months follow up were free of complications. Closure of atrial septal defect with Amplatzer device appears feasible and safe. However, long term results in comparison to surgery remain to be determined before definite conclusion regarding its use can be made.

[History of a wholesaler: CERP-Rouen]

MCPR (Mutuelle cooperative pharmaceutique rouennaise) was created in November 1919 and furnished specialities to pharmacists in Haute-Normandie. It moved to various places and finally was situated in 1939 rue des Augustins, where its central office is still nowadays. During World-War II, many difficulties occurred: fire in 1940, bombing in 1944, great lack of possibilities. After peace, it took benefit of the great increase of its market. It worked for the grouping of wholesalers companies and became in 1965 CERP-Rouen. It strenghtened its internal growth by creating new sites and introducing new techniques: teletransmission computer networks, officinal PC. Since 1969 to 1986, nine wholesalers were partially or totally incorporated in the group and CERP got to a national position: 34 agencies, 6,000 members, 1010 FF. Since 1986, it reached the European level (Belgium, Spain, Poland) and overseas departments (Martinique-Guyane).

Percutaneous closure with Amplatzer device is a safe and efficient alternative to surgery in adults with large atrial septal defects

BACKGROUND

In adults with atrial septal defect (ASD) and large right-to-left shunt, closure of the defect is recommended. Percutaneous closure is still rarely used in this population. This study presents the results of transcatheter closure with the Amplatzer occluder in such patients.

METHODS AND RESULTS

We studied 44 consecutive adult patients with a secundum ASD and 2 of the 3 following criteria: QP/QS >/=2 by oximetry, echocardiographic right ventricle overload, and ASD size >20 mm. Forty-two patients had a successful implantation. In 1 patient an unstable device was withdrawn; in another one, the device embolized in the pulmonary artery. At 6-month median follow-up, 95% had a complete closure; 2 patients with an additional defect had a small residual shunt. Major complications were the aforementioned embolization and a cerebrovascular accident in a patient with atrial fibrillation treated with aspirin. Others were minor and transitory: premature atrial beats in 3 patients, and paroxysmal atrial fibrillation and pulmonary edema in 1 patient each.

CONCLUSIONS

Transcatheter closure of large ASDs with the Amplatzer device is efficient with less morbidity than surgical closure.

Comparison of the effects of stimulating groups of static gamma axons with different conduction velocity ranges on cat spindles

In cat peroneus tertius muscles, static gamma axons were prepared in groups of three to four according to the conduction velocity of their axons (fast, intermediate, or slow). Effects of stimulating these groups (at 20, 30, and 50 Hz) on spindle ensemble discharges during sinusoidal stretch (peak-to-peak amplitude, 0.5 mm; frequency linearly increasing from 0.5 to 8 Hz in 10 s) were compared. Ensemble discharges were obtained by digital treatment of the discharges in afferent fibers from all the spindles in peroneus tertius as recorded from the muscle nerve. Stimulation of each group prevented ensemble discharges from falling to very low levels during shortening phases. However, this effect was clearly larger when the group of fast-conducting axons was stimulated. In view of the known effects of the activation of bag(2) and chain fibers (either separately or together) on single primary ending discharges during comparable sinusoidal stretches, this stronger effect supports the view that static gamma axons with faster conduction velocities are more likely to supply more bag(2) fibers than slower ones. Possibly the proportions of bag(2) and chain fibers activated during motor activity are determined by a recruitment of static gamma motoneurons related to their size.

New anti-inflammatory N-pyridinyl(alkyl)phthalimides acting as tumour necrosis factor-alpha production inhibitors

This paper describes the synthesis of N-pyridinyl(alkyl)phthalimides related to N-phenyl-4,5,6,7-tetrafluorophthalimides known to be inhibitors of tumour necrosis factor-alpha (TNFalpha) production. Pharmacomodulation at the phthalimidic nitrogen led to the selection of two pharmacophoric fragments (2,4-lutidinyl and beta-picolyl), allowing significant inhibition of TNFalpha production (compounds 12 and 17). Variation of the substituents linked to the homocycle of their phthalimide scaffold indicated that high (TNFalpha production) inhibitory potency could be achieved, notably by 5-fluoro, 4- or 5-nitro, 5-amino and especially tetrafluoro substitution. The most active compound, N-(pyridin-3-ylmethyl)-4,5,6,7-tetrafluorophthalimide (32) (84% inhibition at 10 microM), also produced an anti-oedematous effect in the PMA-induced mouse-ear swelling test. Although less active than dexamethasone, it exerted a marked reduction in ear thickness after oral administration (63% vs. 85% for dexamethasone at 0.2 mMkg(-1)) and remained efficient after topical application (46% vs. 96% for the dexamethasone). It also induced potent inhibition in the rat carrageenan foot oedema test with an ID(50) (0.14 microMkg(-1)) comparable with that of N-(2,6-diisopropylphenyl)phthalimide (4) (0.15 microMkg(-1)).

Post-transplant lymphomas: a 20-year epidemiologic, clinical and pathologic study in a single center

BACKGROUND AND OBJECTIVES

To study the incidence, clinical presentation, pathologic features and outcome of post-transplant lymphomas (PTL) during the past 20 years.

DESIGN AND METHODS

We undertook a descriptive study of all biopsy-proven cases of PTL diagnosed in our hospital from 1979 through 1999. The average annual incidence rate of PTL was analyzed at 5-year intervals from 1979 to 1999. Risk ratios were estimated by comparing the incidence of PTL among transplanted patients with that of lymphoma observed in the general population of the region. Survival analysis was performed at the univariate level using the Kaplan Meier technique and at the multivariate level by Cox hazard models.

RESULTS

Seventeen of 1,860 transplanted patients developed a PTL (0.9%). The risk of PTL was calculated to be almost 8-fold higher than the risk of lymphoma in the general population. The risk was highest among those who had received a heart transplant (RR=35.6). The mean time between transplant and the diagnosis of PTL was 31 +/- 29 months. Of all PTL, 88% were of B-cell origin and 53% of the cases tested were Epstein-Barr virus (EBV)-positive. The median survival was 24 months. The majority of patients with allograft involvement died within the 2 months following diagnosis (hazard ratio 5.3; 95% CI 1.4-20.7).

INTERPRETATION AND CONCLUSIONS

Organ transplantation is a major risk factor for the development of lymphoma, a disease with a particularly bad prognosis when it develops at the site of the allograft. Early diagnosis and more specific treatment may improve PTL survival.

Predictive elements in ocular interception and tracking of a moving target by untrained cats

We presented a mechanical target moving at constant velocity to awake, nontrained, head-restrained cats, in order to study how naive animals pursue objects moving at a high speed with their gaze. Eye movements were recorded while the target was moving in different directions at a constant velocity (20-80 degrees/s) through the center of the visual field. We observed two oculomotor strategies: cats either made an interception saccade (IS) toward the target but opposite to its motion, or tracked it in the direction of motion. They used the interception strategy more frequently when the gaze position error at the onset of target motion was large, and the tracking strategy when it was small. Interception was always achieved by single saccades, which were faster than tracking saccades (TS). During tracking, cats generated sequences of two to six saccades separated by "smooth" eye movements. Tracking quality varied considerably from trial to trial. When the level of motivation was high, cats would track the target at 80 degrees/s over up to 75% of the oculomotor range, with relatively small position errors. We compared ISs and TSs with respect to their metric properties and timing. The amplitudes of ISs positively correlated with position error existing 100 ms before saccade onset, but saccade vectors were directed to a point ahead of the target along the target's track. We conclude that, in programming the ISs, target motion is used to predict the future target position so as to assure a spatial lead of the gaze at the saccade end, instead of attempting a precise capture of the target. The amplitude of TSs did not depend on preceding position errors. TSs were usually small at the onset of the first saccade, as if cats would wait till the target arrived near the line of sight. A majority of primary TSs were initiated before the target arrived near the direction of gaze. Thus they had a direction, opposite to the position error sampled 100 ms before the saccade, but the same as the direction of target motion. Prediction of the future target position from its velocity vector should therefore contribute to the programming of TSs. In addition, we observed that TSs were faster when they were initiated with a spatial lag relative to the target and they were slower if there was a spatial lead or target velocity was reduced. Such a modulation appears to be analogous to the predictive correction of the saccade amplitude during smooth pursuit in primates. Considering strong visual motion sensitivity and motor properties of output neurons of the superior colliculus, it is likely that, in cats, the colliculus makes a major contribution to the integration of eye movement-related and target motion-related signals.

[Report of 2 cases of arterio-ureteral fistula]

Uretero-arterial fistulas are exceptional complications: only about forty cases have been reported in the literature. The authors report new two cases of fistula between the common iliac artery and the ureter. One fistula occurred in a context of prolonged ureteric stenting after radiotherapy and pelvic surgery for cancer of the uterus, and the other occurred after an aorto-bifemoral allograft. These fistulas generally occur in a particular clinical context, associating several aetiological factors. The clinical presentation is dominated by often massive and intermittent haematuria. The most useful diagnostic examinations are retrograde ureteropyelography and arteriography. The proposed treatment options (nephrectomy, vascular bypass graft and even embolization) depend on the urgency of the situation and involve both the blood vessel and the urinary tract. The prognosis depends on early diagnosis, but preventive measures can be envisaged to decrease the risk of appearance of these fistulas in high-risk patients.

CHOD/BVAM regimen plus radiotherapy in patients with primary CNS non-Hodgkin's lymphoma

PURPOSE

To assess the efficacy and toxicity, including long-term neurotoxicity, of combined therapy with the CHOD/BVAM regimen given before cranial radiotherapy in the treatment of primary CNS lymphoma (PCNSL).

METHODS AND MATERIALS

Thirty-one consecutive patients with PCNSL were treated with one cycle of cyclophosphamide, doxorubicin, vincristine, and dexamethasone (CHOD) and two of carmustine (BCNU), vincristine, cytosine arabinoside, and methotrexate (BVAM), followed by cranial radiotherapy (45 Gy whole brain plus a 10-Gy boost for single lesions). The median age was 59 years (range 21-70) and 39% had poor performance status. The median follow-up of patients was 4.1 years (range 2.7-9.0).

RESULTS

Twenty-one patients had no PCNSL at the end of treatment. The 5-year actuarial probability of survival was 31% (95% confidence interval [CI]: 11%-57%), with a median survival of 38 months. Patients < 60 years had a survival significantly longer than those > or = 60 years (4-year survival: 58% (95% CI: 34-82%) vs. 29% (95% CI: 5-53%), respectively; p = 0.04). Two patients died during chemotherapy from pulmonary embolism and bronchopneumonia, respectively, with no evidence of PCNSL at the autopsy. Dementia probably related to treatment occurred in 5 (62%) of the 8 patients 60 years and older, and 4 of them died without evidence of relapse of PCNSL. Dementia correlated with developing brain atrophy and leuco-encephalopathy on serial CT or MR scans.

CONCLUSION

This regimen can be given with the planned dose intensity to patients aged less than 70 years, and produces better survival than that reported with radiotherapy alone; however, dementia occurs in the majority of patients aged 60 years of age or more.

Breast reconstructive techniques in cancer patients: which ones, when to apply, which immediate and long term risks?

Breast reconstruction is considered as part of the breast cancer treatment when a mastectomy is required. The techniques available today, allow reconstruction of the breast even in almost all the cases even in poor local conditions. In 60-70% of the cases, the reconstruction can be performed with an implant inserted behind the pectoralis muscle. Special implants called expanders, are inflatable progressively in the postoperative course thanks to a reservoir located subcutaneously. They provide a progressive distention of the teguments and a more natural shape after substitution of the expander with a definitive implant. The symmetry is usually obtained thanks to a contralateral plastic surgery, which allows at the same time histological check up of the glandular tissue of the opposite breast. The nipple areolar complex is usually reconstructed in a second stage under local anesthesia, using local flaps for the nipple and a tattoo for the colour of the areola. In 30% of the cases, especially after radiotherapy when a salvage mastectomy is required, a flap reconstruction is preferred. The autologous tissue reconstruction with the rectus myocutaneous flap gives excellent cosmetic results and the most natural shape for the breast. But it is a more demanding technique requiring a good experience. In some occasions, the reconstruction with the latissimus flap can also be autologous but usually requires the addition of prosthesis. In most cases, the reconstruction can be performed immediately. The delayed reconstruction is usually preferred when the adjuvant chemotherapy should be delivered as soon as possible after the mastectomy. Complications of the reconstruction such as local necrosis or infections, leading to implant removal or revision of the flap could be detrimental to the patient in delaying the start of the chemotherapy. It is not recommended to reconstruct the breast immediately in case of locally advanced breast cancer. Partial breast reconstruction using plastic surgery procedures can also be performed in case of quadrantectomy in order to obtain a better cosmetic result. Local glandular flaps, as well as specific incisions according to the location of the tumor in the breast allow the reshaping of the breast even in case of large resection and, therefore, provide an opportunity to increase the number of conservative treatment indications, especially in case of in-situ carcinomas.

[The legislator's position regarding research perspectives (concerning xenografts and the development of stem cell banks]

Analysis of the legislation concerning xenotransplantation and constitution of stem cell banks reveals an absence of status common to embryos and animals. They do not have any legal status, they are not assimilated to objects, but benefit from protective measures. Xenotransplantation is regulated by a set of rules, while embryo research is currently prohibited in France, but is regulated in other countries. Bioethical legislation raises difficulties related to the early stage of its development and its perverse effects. The consultation process prior to defining legislation must take into account the international dimension and the necessary progress of scientific research.

Autologous stem cell transplantation (ASCT) with immunologically purged progenitor cells in patients with advanced stage follicular lymphoma after early partial or complete remission: toxicity, follow-up of minimal residual disease and survival

The role of autologous stem cell transplant (ASCT) in indolent lymphomas is a controversial issue. From 1994 to 1999, we performed ASCT with immunologically purged progenitor cells in 15 patients with advanced stage follicular lymphoma (FL) after early partial or complete remission. Results of the purging strategy and follow-up of minimal residual disease after transplant were analyzed with PCR amplification of bcl-2/IgH rearrangement for the t(14;18) translocation. A comparison of transplanted patients with a group of controls was carried out to evaluate differences in progression-free survival and overall survival. Eighty percent of patients received one chemotherapy regimen before ASCT and were in first remission. All the patients received cyclophosphamide plus hyperfractionated total body irradiation as the conditioning regimen. Nine patients were transplanted with bone marrow (BM) and six with peripheral blood progenitor cells (PBPC). Engraftment was delayed in one patient transplanted with BM. Two patients died during the transplant procedure. Ten of 12 evaluable patients were PCR positive in the BM for bcl-2 rearrangement at diagnosis. Six of them (60%) were still positive after chemotherapy, and one patient was transplanted with a positive hematopoietic product after purging. With a median follow-up of 27 months, six of eight evaluable patients still remain PCR negative in the BM. With a median follow-up of 4.7 years from diagnosis, progression-free survival was 83% (95% CI: 63-100). The risk of disease progression of non-transplanted patients was 19.2 times higher than that of transplanted patients (P = 0.01), but no differences were found in overall survival. Regarding patients in first remission, the risk of relapse was 12.6 times higher in non-transplanted than in transplanted patients (P = 0.04). This procedure seems to offer a good chance to achieve a PCR-negative state and prolonged freedom from recurrence. According to these results, prospective randomized trials are warranted.

Mapping, characterization, and expression analysis of the SM-20 human homologue, c1orf12, and identification of a novel related gene, SCAND2

Major psychosis was shown to segregate with a balanced translocation (1q42.1; 11q14.3) in a multigenerational family. This study describes the identification of a human SM-20 homologue gene that lies at about 400 kb on the centromeric side of the 1q42.1 breakpoint. The full-length cDNA sequence and gene structure were determined. Expression analysis was performed, showing high expression levels in skeletal and cardiac muscles; in the central nervous system, expression was restricted to dopaminergic neurons and spinal motoneurons. A second gene displaying high sequence similarity with SM-20 was also identified by BLAST. This gene, located on chromosome 15, is likely to have evolved by retroposition of SM-20 mRNA and an exon-shuffling mechanism. It encodes a 306-amino-acid protein harboring strong homology with an N-terminal motif found in some zinc-finger proteins. This gene was named SCAND2 (SCAN domain-containing 2).

Cyclosporine bone remodeling effect prevents steroid osteopenia after kidney transplantation

BACKGROUND

It is well established that prednisone above 7.5 mg/day may induce osteopenia in association with decreased bone formation. In contrast, the effect of cyclosporine on bone remodeling and bone mineral density (BMD) is controversial. Multiple confounding factors explain this controversy, especially after renal transplantation.

METHODS

Fifty-two renal transplanted patients never exposed to aluminum while on dialysis were selected because they had no rejection and no hypercalcemia for 24 months while being treated with low dose prednisone/cyclosporine A (daily dose at 10 mg and 4.8 mg/kg, respectively, beyond 3 months). Bone remodeling markers (BRMs; plasma osteocalcin, bone and total alkaline phosphatases for formation, and urinary pyridinolines for resorption) were sequentially measured together with plasma creatinine, intact parathyroid hormone (PTH) and 25 OH vitamin D and cyclosporine from day 0 to 24 months. BMD was measured at 3, 6, 12, and 24 months by quantitative computerized tomography (QCT) at the lumbar spine and by double-energy x-ray absorptiometry (DEXA) at this site, as well as at the femoral neck, radius shaft, and ultradistal (UD) radius.

RESULTS

Plasma concentrations of creatinine, PTH, and 25 OH vitamin D initially decreased and stabilized beyond three months at 137 micromol/L, 1.5 the upper limit of normal (ULN) and 11 ng/mL, respectively. All BRM increased significantly above the ULN at six months and then decreased. The BMD Z score at three months was low at all sites measured by DEXA and QCT. Follow-up measurements showed stability of absolute value and of Z score at all sites measured by DEXA. A comparison of the lumbar QCT Z score, which was available in 42 patients at 3 and 24 months, showed an increase in 28 and a decrease in 14, so that the increase for the whole group was significant (P < 0.04). Compared with patients with a decreased Z score, those with an increased Z score had significantly higher cyclosporine and lower prednisone dosages and a greater BRM increase at six months, whereas age, sex ratio, and plasma creatinine, PTH and 25 OH vitamin D were comparable and stable from months 3 through 24. The mean trough level of cyclosporine for the first six months was positively correlated to osteocalcin and total alkaline phosphatase increase at six months, and both bone formation and resorption marker increases were significantly correlated to the lumbar QCT Z score increase at 24 months.

CONCLUSIONS

Combined low-dose prednisone and cyclosporine immunosuppression are associated with a stabilization of BMD measured at all sites with DEXA 3 to 24 months after renal transplantation and with a prevention of age-related loss of vertebral trabecular bone, as shown by the significant increase in lumbar spine QCT Z score. It is suggested that cyclosporine, together with the decrease of prednisone dosage but independent of renal function, PTH, and vitamin D status, contributes to a transient stimulation of bone remodeling at six months, which counterbalances the deleterious effect of prednisone on bone formation and BMD.

[Mesothelial cyst of the adrenal gland]

We report a case of a mesothelial adrenal cyst which was incidentally discovered in a 38-year old woman. The diagnosis was confirmed by an immunohistochemistry study. Adrenal cysts are rare. They occur more commonly in female patients during the 4th and 5th decades and are usually asymptomatic. Adrenal cysts are divided into four groups : parasitic, epithelial, endothelial cysts and pseudocysts. The management is still discussed : follow-up, surgical resection or fine-needle aspiration.

The violent patient

Encounters with violent behavior are an inevitable part of working in emergency departments. By adoption of a cohesive, multidisciplinary approach to behavioral decompensation, as is done in preparation for airway compromise, the risk for injury to patients and staff is minimized. As with airway compromise, anticipation of and preparation for deterioration can avoid the necessity of the most invasive measures and can ensure a calm, positive outcome. With the appropriate knowledge, teamwork, and skills, even patients requiring the most intensive intervention can be treated safely and professionally.

High-performance liquid chromatographic determination of phenylephrine and tropicamide in human aqueous humor

A high-performance liquid chromatographic method for the simultaneous determination of phenylephrine and tropicamide in human aqueous humor was developed. After centrifugation, an aliquot of the supernatant was injected onto the column and the eluent was monitored at 280 nm then 254 nm after 5 min. Separation was performed on a CN column with 0.01 M Pic B8 (octane sulfonic acid)-acetonitrile (65:35, v/v) as mobile phase. The standard curves were linear in the detection range. The precision of the method (expressed by relative standard deviation) and the accuracy (mean error in per cent) were <5% for both intra- and interassays.

Transaortic closure of residual intramural ventricular septal defect

BACKGROUND

Residual intramural ventricular septal defect is an unusual cause of left-to-right shunt after biventricular repair of conotruncal anomalies. It results from the insertion of the patch within the trabeculated right ventricular free wall related to the ventriculoinfundibular fold creating a communication through the intertrabeculated spaces to the right ventricular cavity. This complication often leads to unsuccessful reoperations unless the exact mechanism of the shunt has been identified.

METHODS AND RESULTS

Five patients presented with residual intramural ventricular septal defects. Three had double outlet right ventricle, one pulmonary atresia with ventricular septal defect, and one tetralogy of Fallot. One patient was unsuccessfully reoperated on for closure of the residual ventricular septal defect through the right ventricular approach. The surgical treatment, which consisted of patch closure of the residual intramural ventricular septal defect through aortotomy, was successful in 3 patients. In the 2 remaining patients the hemodynamically insignificant residual intramural ventricular septal defect remained untouched. No mortality or morbidity occurred.

CONCLUSIONS

Residual intramural ventricular septal defect should be suspected in presence of a residual ventricular septal defect after biventricular repair of conotruncal anomalies. It is not accessible through either atriotomy or right ventriculotomy. The transaortic approach allows an easy treatment of this rare complication.

High prevalence of hepatitis C virus infection in Belgian intravenous drug users and potential role of the "cotton-filter" in transmission: the GEMT Study

AIMS

To estimate viral seroprevalences for HCV, HBV and HIV among belgian intravenous (IVDU) and non intravenous (non-IVDU) drug users; to assess risk factors for HCV infection in IVDU; to assess feasibility of chronic hepatitis C follow-up in this population.

DESIGN

Cross-sectional study. Demographic and behavioural characteristics were obtained by a standardized questionnaire. Serum samples were tested for HCV, HBV and HIV.

SUBJECTS AND SETTING

329 patients (244 IVDU and 85 non-IVDU) attending ten general practitioners in 1995.

RESULTS

HCV seroprevalence was 78.3%; it was 35.7% for HBV and 0.9% for HIV in IVDU, vs 2.4%, 8.3% and 0%, respectively, in non-IVDU. In logistic regression analysis, independent risk factors for HCV infection were: 1/sharing of syringes and/or of "cottons" used as filters (adjusted prevalence odds ratio [POR] = 31.7; 95% confidence interval [CI] = 9.8-102.5), 2/duration of injecting upper than one month (adjusted POR = 8.6; CI = 3.0-24.7) and 3/age (adjusted POR = 1.2 by year of difference; CI = 1.0-1.3). A biochemical follow-up was obtained in 70% of HCV seropositive users; 79.5% of them had chronic hepatitis C (mean value of ALT = 3.5 times upper normal value, range 1.1-23.0). Among these, 24.7% went through liver biopsy during the three years follow-up period of the study.

CONCLUSIONS

HCV seroprevalence is very high among belgian IVDU. Prevention strategies have to focus on neophytes injectors. They must be urgently revisited for what concern needles/syringes exchange programs: "cottons" must be included. Follow-up and treatment of chronic hepatitis C seem to be poorly effective among drug users.

[Ring chromosome 20: an identifiable epileptic syndrome]

Ring chromosome 20 (RC20) is a rare chromosomopathy characterized by slight mental deficiency, behavioral disorders and epilepsy. We report two cases of ring chromosome 20, who exhibited non convulsive status epilepticus lasting minutes to hours, often triggered by emotional events, with associated typical electroencephalographic features. Our report highlights the features of the electroclinical epilepsy syndrome associated with RC20, which represents a distinct and recognizable entity. The genetic basis of this disorder is discussed.

Mini-ICE regimen as mobilization therapy for chronic myelogenous leukaemia patients at diagnosis

Between April 1996 and May 1998, 20 consecutive patients with Ph chromosome-positive CML in first chronic phase without an HLA-identical sibling received the mini-ICE regimen shortly after diagnosis to mobilize progenitor cells into the peripheral blood (PBPCs). The sex distribution was 12 males and eight females and the median (range) age 48.5 (22-62) years. The time interval between diagnosis and mobilization was a median (range) of 2 (0-5) months. Leukaphereses were initiated during recovery from chemotherapy-induced aplasia. A median number of 3 (1-7) aphereses per patient were performed to collect >/=2.0 x 106 CD34+cells/kg. Cytogenetic analysis was performed on the aphereses products of 18 patients. Complete cytogenetic Ph chromosome negativity was observed in four patients, nine had a partial negativity, three a minimal negativity and two no negative cells. Southern blot for bcr-abl was negative in the remaining two patients but the polymerase chain reaction analysis was positive. Following reinfusion, severe neutropenia was present for a median of 8.5 (3-19) days and severe thrombocytopenia lasted a median of 8 (3-18) days. Ten patients did not develop febrile neutropenia with four of them being treated on an outpatient basis. Treatment-related mortality was not observed. In conclusion, our experience demonstrates the feasibility of mobilizing PBPCs shortly after the diagnosis of CML with a safe regimen. Of note, mini-ICE allowed the collection of apheresis products with at least a major component of Ph-negative cells in almost 75% of the patients.

Non-convulsive status in the ring chromosome 20 syndrome: a video illustration of 3 cases

We report the clinical history and the video-EEG recordings of three young adults with r(20), who exhibited repeated episodes of non-convulsive status epilepticus, often triggered by emotional events. This recognizable clinical entity associates a slight mental deficiency, behavioural disorder and epilepsy, often resistant to treatment and with a particular clinical presentation. We demonstrate with video EEG recording, atypical absence status triggered by emotional behaviour with ictal EEG characterized by bifrontal slow waves, often rhythmic, or sharp waves. Our report highlights the characteristic features of non-convulsive status in this electro-clinical syndrome.

Administration of recombinant human granulocyte colony-stimulating factor to normal donors: results of the Spanish National Donor Registry. Spanish Group of Allo-PBT

A Spanish National PBPC Donor Registry has recently been established for short- and long-term safety data collection in normal donors receiving rhG-CSF. To date, 466 donors have been included in the Registry. Median (range) dose and duration of rhG-CSF administration was 10 microg/kg/day (4-20) and 5 days (4-8), respectively. Donors underwent a median of two aphereses (range, 1-5). Adverse effects consisted mainly of bone pain (90.2%), headache (16.9%) and fever (6. 1%), but no donor discontinued rhG-CSF prematurely due to toxicity. Side-effects were more frequent in donors receiving >10 microg/kg/day than in those with lower doses (82.8% vs 61.8%; P = 0. 004). A significant decrease between baseline and post-apheresis platelet counts was the most important analytical finding (229 x 10(9)/l vs 140 x 10(9)/l; P < 0.0001), with a progressive reduction in platelet count with each apheresis procedure. One donor developed pneumothorax that required hospitalization due to central venous line placement. The mean CD34+ cell dose collected was 6.9 x 10(6)/kg (range, 1.3-36), with only 14 donors (2.9%) not achieving a minimum target of CD34+ cells of 2 x 10(6)/kg. No definitive information about potential long-term side effects is yet available. However, we hope this National Registry will serve as a useful basis for better monitoring of the efficiency and side-effects of cytokine administration in healthy people.

Testing the classification of static gamma axons using different patterns of random stimulation

The possibility of using randomly generated stimulus intervals (with a Poisson distribution) to identify the type(s) of intrafusal fiber activated by the stimulation of single static gamma axons was tested in Peroneus tertius muscle spindles of anesthetized cats. Three patterns of random stimulation with different values of mean intervals [20 +/- 4. 47, 30 +/- 8.94, and 40 +/- 8.94 (SD) ms] were used. Single static gamma axons activating, in single spindles, either the bag2 fiber alone or the chain fibers alone or both types of intrafusal fiber were prepared. Responses of spindle primary endings elicited by the stimulation of gamma axons were recorded from Ia fibers in cut dorsal root filaments. Cross-correlograms between stimuli and spikes of the primary ending responses, autocorrelograms, interval histograms of responses, and stimulations were built. The characteristics of cross-correlograms were found to be related not only to the type of intrafusal muscle fibers activated but also to the parameters of the stimulation. Moreover some cross-correlograms with similar characteristics were produced by the activation of different intrafusal muscle fibers. It also was observed that, whatever the type of intrafusal muscle fiber activated, cross-correlograms could exhibit oscillations after an initial peak, provided the extent in frequency of the primary ending response was small; these oscillations arise in part from the autocorrelation of the primary ending responses. Therefore, cross-correlograms obtained during random stimulation of static gamma axons cannot be used for unequivocally identifying the type(s) of intrafusal muscle fiber these axons supply.

Feasibility of ESHAP + G-CSF as peripheral blood hematopoietic progenitor cell mobilisation regimen in resistant and relapsed lymphoma: a single-center study of 22 patients

The purpose was study the feasibility of ESHAP + G-CSF for peripheral blood hematopoietic progenitor cell (PBPC) mobilisation in resistant/relapsed Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL). Twenty-two consecutive patients with HD (8) and N-HL (14) received ESHAP chemotherapy and G-CSF (5 microg/Kg/d). When a minimum number of 10,000 peripheral blood CD34+ cells/mL was observed patients underwent leukapheresis until a CD34+ cell dose > or = 2.5x10(6)/Kg was collected or the PBPC peak was lost. Blood cells kinetics and toxicity were analysed. Data concerning the day of first apheresis, number of procedures per patient, and cellular yield of the aphereses were recorded. Correlation between the CD34+ cell content in the apheresis product and the two diagnosis groups was attempted. Twelve patients (54%) developed short-lived severe neutropenia (<0.5x10(9)/L). Thrombocytopenia (<25x10(9)/L) had a median duration of 1 day. Fever appeared in 4 patients and CN Staph bacteriemia in 2 cases. Bleeding events did not supervene and no deaths occurred. Aphereses started at day +15 (median) and the median number of apheresis/patient was 2. Seventeen patients underwent 1 or 2 leukaphereses. Thirteen patients (59%) achieved the CD34+ cell target in the first apheresis. NHL patients obtained statistically significant better CD34+ cell collections than HD. Only 2 HD patients failed to mobilise, 1 previously treated with high-dose therapy and autologous bone marrow transplantation. ESHAP + G-CSF has been shown to be feasible for PBPC mobilisation in resistant/relapsed lymphoma. Toxicity was low and CD34+ cell yield high, especially in N-HL. This mobilisation regimen should be further explored in a larger patient population.

[Right postero-lateral thoracotomy for open heart surgery in infants and children. Indications and results]

In order to avoid the aesthetic prejudice of median sternotomy in young children undergoing open heart surgery for isolated congenital heart disease, a right posterolateral thoracotomy was performed in 146 children aged 5 months to 14 years. The large majority (140/146, 96%) were atrial septal defects: 130 ostium secundum, 5 sinus venosus, 1 low septal defect and 4 ostium primum (partial endocardial cushion defect). Six children had isolated perimembranous ventricular septal defects. One patient died of a probable lesional pulmonary oedema. Minor complications were observed in 15 cases and one had to be reoperated for a residual shunt. With an average follow-up of 2.6 years, all survivors are asymptomatic. The scar is normal, without cheloid or thoracic deformation, invisible to the patient when he looks in a mirror. The use of this approach requires a very accurate anatomical diagnosis, especially with regards to systemic and pulmonary drainage. The presence of a left superior vena cava draining into the coronary sinus is a contra-indication. The right posterolateral thoracotomy is now the approach of choice in its standard indication, the repair of ostium secundum atrial septal defects with large shunts, in young girls under 10 years of age.

[Interpretation of standard chest x-rays in thoracic trauma: influence of the experience of the interpreter]

OBJECTIVE

To compare the quality of interpretation of chest radiographs (CRs) by physicians of different levels of experience, with reference to data obtained from helicoidal computed tomography (HCT).

STUDY DESIGN

Prospective observational study.

MATERIAL

CRs of 50 thorax trauma patients as recent to HCTs as possible obtained within the 48 h following admission to the intensive therapy unit.

METHOD

CRs were analyzed according to a grid by observers included in one of the four groups: residents in anaesthesiology (n = 6), residents in radiology (n = 3), senior anaesthesiologists (n = 5), and senior radiologists (n = 3). The inter-observer agreements, the specificity and sensibility of each group with reference to HCT, and their global performances were assessed.

RESULTS

Inter-observer agreements were poor and sensitivities low in comparison to specificities. No group of observers performed better than another one. These data substantiate the low sensitivity of CRs in comparison to HCT and show that the quality of interpretation of CRs of thorax trauma patients is not influenced by physicians' experience.

Transepithelial transport of bepridil in the human intestinal cell line, Caco-2, using two media, DMEMc and HBSS

The purpose of this work was to study transepithelial transport of bepridil, an anticalcic agent, through monolayer cells Caco-2, using two experimental media with different chemical components. For experimentation, the measure of the transepithelial electrical resistance (TEER) allowed us to evaluate the state of cells; and the quantities of bepridil have been quantified using a gas chromatography/mass spectrometry system. First, when using the medium alone, without bepridil, Caco-2 cell integrity is, at least, maintained for 8 h using both media. However, for 24-h studies, only the DMEMc medium, rich in essential nutriments, allowed cell integrity to be maintained. Then, with bepridil in HBSS medium, the TEER measurement showed a dose-dependent toxic effect of bepridil, whereas in the DMEMc medium, the toxic effect was only found for the highest dose (12 microg). This difference is probably related to the high binding of bepridil to proteins of the DMEMc medium, therefore minimising the concentration of the free compound. The kinetics of bepridil result from two phenomena: first, an immediate passage of a slight part of bepridil through the cell barrier and second, a high retention of most of the bepridil dose in the cell level. The transfer of bepridil from the apical to the basolateral compartment appears quantitatively and kinetically different using DMEMc or HBSS medium. The retention of the compound in the 'filter with Caco-2 cells' compartment is higher in DMEMc medium (60% at 3 microg) than in HBSS medium (46% at 3 microg), and bepridil entering the basolateral compartment is delayed in the DMEMc medium. This study exhibits the importance of the selected medium on results and interpretation of data and the predominance of DMEMc to study the transport of lipophilic compounds highly retained in cells.

Saccades and multisaccadic gaze shifts are gated by different pontine omnipause neurons in head-fixed cats

Pontine omnipause neurons (OPNs) have so far been considered as forming a homogeneous group of neurons whose tonic firing stops during the duration of saccades, when the head is immobilized. In cats, they pause for the total duration of gaze shifts, when the head is free to move. In the present study, carried out on alert cats with fixed heads, we present observations made during self-initiated saccades and during tracking of a moving target which show that the OPN population is not homogeneous. Of the 76 OPNs we identified, 39 were found to have characteristics similar to those of previously described neurons, "saccade" (S-) OPNs: (1) the durations of their pauses were significantly correlated with the durations of saccades; (2) the discharge ceased shortly before saccade onset and resumed before saccade end; (3) visual responses to target motion were excitatory; and (4) during tracking, S-OPNs interrupted the discharge for the duration of saccades and resumed firing during perisaccadic "drifts". However, the characteristics of 37 neurons ("complex" (C-) OPNs) were different: (1) the pause duration was not correlated with the duration of self-initiated saccades; (2) time lead of pause onsets relative to saccades was, on average, longer than in the group of S-OPNs, and firing resumed after the saccade end; (3) visual target motion suppressed tonic discharges; and (4) during tracking, firing was interrupted for the total duration of gaze shifts, including not only saccades but also perisaccadic "drifts". We conclude that cat OPNs can be subdivided into two main groups. The first comprises neurons whose firing patterns are compatible with gating individual saccades ("saccade" OPNs). The second group consists of "complex" OPNs whose firing characteristics are appropriate to gate total gaze displacements rather than individual saccades. The function of these neurons may be to disinhibit pontobulbar circuits participating in the generation of saccade sequences and associated perisaccadic drifts.

[Paraneoplastic opsoclonus-myoclonus syndrome revealing T-cell lymphoma]

BACKGROUND

Nonrhythmic involuntary ocular oscillations and axial and segmentary myoclonia are associated in the opsoclonus-myoclonus syndrome. In adults, a paraneoplastic origin is generally found. We report the first of opsoclonus-myoclonus associated with non-Hodgkin's lymphoma.

CASE REPORT

A 66-year-old woman rapidly developed a typical opsoclonus-myoclonus syndrome within a few hours, presenting vertigo, cerebellous ataxia, multidirectional involuntary ocular movements and non-rhythmic axial and segmentary myoclonia. Brain computed tomography and magnetic resonance imaging demonstrated discrete diffuse anomalies of the white substance predominating in the pons. The cerebrospinal fluid showed discrete lymphocytosis. Antineuron antibodies were negative. No cause could be identified until the development 11 months later of pleomorphic T-cell mediastino-cervical lymphoma. The patient responded moderately to a CHOP regimen which had no effect on the opsoclonus-myoclonus syndrome. Death occurred after a 16-month course due to pulmonary complications.

DISCUSSION

Neuroblastoma and infectious causes predominate in opsoclonus-myoclonus syndromes observed in children; in adults, the predominant cause is cancer. Antineuron, anti-Ri and anti-Hu antibodies can be evidenced in some cases, arguing in favor of a paraneoplastic mechanism. Recent reports have evidenced MRI anomalies in the pons and the cerebellum, anatomically well correlated with the opsoclonus-myoclonus syndrome. Besides small-cell bronchogenic anaplastic cancer, the possibility of cancer of the breast and uterus, and both non-Hodgkin and Hodgkin lymphoma should be explored, knowing the cancer develops several month after the opsoclonus-myoclonus syndrome.

Simple and sensitive method for determination of metronidazole in human serum by high-performance liquid chromatography

A simple and sensitive HPLC method for determination of metronidazole in human plasma has been developed. A step of freezing the protein precipitate allowed an efficient separation of aqueous and organic phases minimizing the noise level and improved therefore the limit of quantitation (10 ng ml(-1) using 1 ml of plasma sample). The separation of compounds was performed on a RP 18 column with acetonitrile-aqueous 0.01 M phosphate solution (15:85, v/v) as mobile phase. Detection was performed by UV absorbance at 318 nm. Metronidazole was well resolved from the plasma constituents and internal standard. An excellent linearity was observed between peak-height ratios plasma concentrations over a concentration range of 0.01 to 10 microg ml(-1). Within-day and between-day precision (expressed by relative standard deviation) and accuracy (mean error in per cent) did not exceed 4% between 1 and 10 microg ml(-1) and 8.3 and 7.2% respectively for the limit of quantitation. The method is suitable for bioavailability and pharmacokinetic studies in humans.