Construction of enantioenriched polysubstituted hexahydropyridazines via a sequential multicatalytic process merging palladium catalysis and aminocatalysis.

An efficient multicatalytic strategy for the construction of nitrogen-containing heterocycles has been reported. The powerful combination of organic and metal catalysis in a single vessel allowed the formation of enantioenriched polysubstituted cyclic 6-membered hydrazines bearing a quaternary stereocenter in good yields and selectivities.

Increasing mean arterial pressure during cardiac surgery does not reduce the rate of postoperative acute kidney injury.

INTRODUCTION: We hypothesized that the optimization of renal haemodynamics by maintaining a high level of mean arterial blood pressure (MAP) during cardiopulmonary bypass (CPB) could reduce the rate of acute kidney injury (AKI) in high-risk patients. METHODS: In this randomized, controlled study, we enrolled 300 patients scheduled for elective cardiac surgery under cardiopulmonary bypass. All had known risk factors of AKI: serum creatinine clearance between 30 and 60 ml/min for 1.73 m(2) or two factors among the following: age >60 years, diabetes mellitus, diffuse atherosclerosis. After a standardized fluid loading, the MAP was maintained between 75-85 mmHg during CPB with norepinephrine (High Pressure, n=147) versus 50-60 mmHg in the Control (n=145). AKI was defined by a 30% increased of serum creatinine (sCr). We further tested others definitions for AKI: RIFLE classification, 50% rise of sCr and the need for haemodialysis. RESULTS: The pressure endpoints were achieved in both the High Pressure (79 ± 6 mmHg) and the Control groups (60 ± 6 mmHg; p<0.001). The rate of AKI did not differ by group (17% vs. 17%; p=1), whatever the criteria used for AKI. The length of stay in hospital (9.5 days [7.9-11.2] vs. 8.2 [7.1-9.4]) and the rate of death at day 28 (2.1% vs. 3.4%) and at six months (3.4% vs. 4.8%) did not differ between the groups. CONCLUSION: Maintaining a high level of MAP (on average) during normothermic CPB does not reduce the risk of postoperative AKI. It does not alter the length of hospital stay or the mortality rate.

A national survey of acute hepatitis E in France.

BACKGROUND: Few data are available on the incidence, risk factors and contamination pathways involved in acute indigenous hepatitis E in developed countries. AIMS: To draw up an overall picture of hepatitis E cases, to confirm whether or not the majority of the cases were indigenous and to attempt to identify the risk factors and contamination pathways involved in hepatitis E. METHODS: This study was performed in the framework of a national network (ANGH) including 96 participating centres. The 19 centres with at least one case of acute HEV reported a total number of 53 cases. RESULTS: A decreasing South-to-North geographic gradient was observed. A nonspecific clinical profile was observed in many cases. Acute hepatitis E was of indigenous origin in 90% of the patients. The most relevant and/or frequent possible risk factors among the 47 indigenous metropolitan cases were water consumption from a personal water supply, uncooked shellfish consumption and the recent acquisition of a pet pig. CONCLUSIONS: This national survey confirmed that acute indigenous hepatitis E is an emerging disease in developed countries such as France, and suggests that various risk factors are responsible for acute indigenous hepatitis E contamination in non-endemic countries.

Evaluation of pollutant exposure by chemical and biological markers in a Mediterranean French urban stream: a step for in situ calibration of multixenobiotic resistance transporter expression as biomarker in Chironomidae larvae.

This study was aimed at semi-quantifying the membrane density of multixenobiotic resistance (MXR) transporters in Chironomidae Orthocladiinae larvae from an urban stream by ELISA assay. The relationships between the MXR transporter membrane density and limnological parameters and pollutant concentrations, 16 priority polycyclic aromatic hydrocarbons (PAHs), as per the US Environmental Protection Agency (EPA) and seven polychlorobiphenyl congeners (PCBs), were assessed. Midge larvae were collected, and limnological parameters and pollutant concentrations were measured in three sites of a French Mediterranean urban stream, two located after sewage treatment plants, and one closed to the river mouth, and in two additional sites, one on the stream tributary, and one in a non-urbanized stream located in the same region. Results show that the PAH and PCB contamination levels are different between sites and that some congener concentrations are above their threshold toxic effect level (TEL). The MXR transporter membrane density was significantly higher in larvae from the tributary, the most polluted site, as compared with larvae from the non-urbanized stream. The MXR transporter density was positively correlated with 10 of the 16 US-EPA PAH concentrations and the increase in the MXR transporter density seems to be due to the US-EPA PAH concentrations that were above their TEL. No relations with PCB concentrations or limnological parameters were found. The results suggest that the MXR transporter membrane density in Chironomidae larvae could be an interesting biological marker of PAH exposure in freshwater ecosystems.

ELISA detection of multixenobiotic resistance transporter induction in indigenous freshwater Chironomidae larvae (Diptera): A biomarker calibration step for in situ monitoring of xenobiotic exposure.

A new simple and sensitive method to distinguish chemically polluted from unpolluted situations in freshwater ecosystems is reported. For this purpose, Chironomus gr thumni larvae were collected from a polluted urban river downstream a sewage treatment plant. For the first time, ELISA assay was used to semi-quantify the multixenobiotic resistance transporters (MXR) in these small pertinent bioindicators. The use of samples immediately fixed in the field gives a delay to isolate larvae and allows multi-sampling along a longitudinal transect in a river at a given time. Results exhibit an induction of MXR proteins in larvae from the polluted river and a deinduction in larvae maintained 11days in unpolluted water. They show new evidences to use midge larvae in biomonitoring environmental programs. They answer to first biomarker calibration steps for the ongoing development of MXR transporters as a detection tool of xenobiotic impacts on bioindicator invertebrates in their freshwater habitats.

Retreatment with interferon and ribavirin vs interferon alone according to viraemia in interferon responder-relapser hepatitis C patients: a prospective multicentre randomized controlled study.

Low pretreatment viral load has consistently been shown to be an independent predictor of sustained response (SR) in patients with chronic hepatitis C infection. We assessed the efficacy of interferon (IFN) plus ribavirin vs IFN alone in low viraemic patients (<2 millions copies/mL) who had relapsed to a previous course of IFN and the efficacy of 24 vs 48 week combination therapy in high viraemic patients. Two hundred and ninety-seven patients were randomly assigned to one of the four regimens after stratification on pretreatment viral load. All patients received IFN-alpha2b (6 million units thrice weekly for 24 weeks and 3 million units thrice weekly for 24 weeks). Patients with low viraemia received either IFN-alpha2b alone for 48 weeks (R1: 42 patients) or IFN-alpha2b plus ribavirin (600 mg/day) for 24 weeks and IFN-alpha2b alone for the next 24 weeks (R2: 48 patients). Patients with high viral load received either IFN-alpha2b plus ribavirin for 24 weeks and then IFN-alpha2b alone for the next 24 weeks (R3: 104 patients) or IFN-alpha2b plus ribavirin for 48 weeks (R4: 103 patients). In low viraemic patients the rate of SR was 37.7% in group R1 and 59.6% in group R2 (P < 0.05). In high viraemic patients, the rate of SR was 44.7% in group R3 and 51.4% in group R4 (P: NS). Thirty-one patients discontinued treatment (10.4%) without difference regarding treatment regimen. In the regimen using ribavirin we found no difference in terms of SR between patients receiving a dose of ribavirin below 10.6 mg/kg/day (55%) or over 10.6 mg/kg/day (58%). Histological improvement occurred in 70.2% of patients regardless of the regimen. Logistic regression showed that genotype 2 and 3, Knodell score <6 and alanine aminotransferase pretreatment level >3 x upper limit of normal were significantly and independently correlated with SR. In low viraemic patients who relapsed to a previous IFN treatment, combination therapy using high-dose IFN and low-dose ribavirin is better than high-dose IFN alone. In high viraemic patients there was no benefit in increasing the duration of combination therapy from 24 to 48 weeks. In this study, it was found that low dose of ribavirin can be used safely and there is no effect of ribavirin dose on SR.

Evidence for the presence of serotonin in Mysidacea (Crustacea, Peracarida) as revealed by fluorescence immunohistochemistry.

In crustaceans, serotonin (5-HT) exerts a wide range of physiological actions on many tissues. However, 5-HT has not been detected to date in Mysidacea (Crustacea, Peracarida). We have investigated the presence of 5-HT in the brain and the eyestalks of two Mysida (Leptomysis lingvura, Hemimysis margalefi) and one Lophogastrida (Lophogaster typicus) species by using the immunohistofluorescence technique. 5-HT-like immunopositive areas exhibit a similar pattern in the three species. 5-HT-like immunostaining is present in the retinular photosensitive cells, except in the deep-living species L. typicus. 5-HT-like cell bodies and fibres are observed in the lamina ganglionaris and in the three medullae. In the sinus gland, only 5-HT-like endings are detected. In the eyestalks, 5-HT-like fibres detected in the optic tract link with the protocerebrum, in which 5-HT-like somata and their extensions are found. Some neurones are detected in the anterior median cell cluster, in the protocerebral bridge and in the central body. In the deutocerebrum, the paracentral lobes are connected by immunoreactive fibres that run along the deutocerebral commissure. The glomeruli of the olfactory lobes exhibit strong diffuse immunostaining. Beside and in the median part of the deutocerebrum, at least two large serotoninergic neurones project their axons into the olfactory lobe cell cluster. Immunoreactive fibres are also found in the antennular neuropiles. Our results demonstrate the presence of 5-HT-like cell bodies and fibres in Mysidacea. The distribution patterns of the 5-HT immunoreactivity found herein are compared with those of other peracarids and decapods.

Chronic effects of triiodothyronine in combination with imipramine on 5-HT transporter, 5-HT(1A) and 5-HT(2A) receptors in adult rat brain.

Triiodothyronine (T3) has been shown to accelerate and potentiate the clinical response to tricyclic antidepressant (TCA) treatment in depressive disorders. The neurobiological mechanisms underlying these therapeutic effects of T3 are still unknown. Since brain serotonin (5-HT) changes have been implicated in the mode of action of TCA drugs, the effects of a chronic (7 or 21 days) administration of imipramine (10 mg/kg/day) and of a low dose of T3 (4 microg/kg/day), given alone or in combination, were investigated on the density of midbrain 5-HT transporters and of hippocampal 5-HT(1A) and cortical 5-HT(2A) receptors in adult Wistar rats. Neither single nor combined administration of imipramine and T3 for 7 days modified the density of 5-HT transporters and of 5-HT(1A) receptors. On day 21, the combination did not change imipramine- or T3-induced decrease in 5-HT transporter density whereas it prevented imipramine-induced increase in 5-HT(1A) receptor density. Whatever the treatment duration, imipramine-T3 combination potentiated imipramine-induced decrease in 5-HT(2A) receptor density. On both day 7 and day 21, T3 given alone had no effects on the density of 5-HT(1A) and 5-HT(2A) receptors. These data indicate that T3 is able to modulate the long-term adaptive changes which occur at the postsynaptic level of 5-HT neurotransmission after antidepressant treatment.

Red blood cell triiodothyronine uptake in unipolar major depression: effect of a chronic antidepressant treatment.

The evolution of kinetic parameters (Vmax, maximal velocity, and Km, Michaelis constant) of red blood cell (RBC) triiodothyronine (L-T3) initial uptake was followed in 19 inpatients suffering from unipolar depression after 1 week (D7) and 4 weeks (D28) of a chronic administration of fluvoxamine, in relation with the clinical efficacy of the drug. In a drug-free state (DO), Vmax (in pmol/min/10(8) cells) and Km (in nM) were significantly increased in depressed patients (Vmax +/- S.D.= 1.02 +/- 0.29, p< 0.01 and Km +/- S.D.= 68.8 +/-15.4, p< 0.05; n=19) compared to healthy volunteers matched for age and sex (Vmax +/- S.D.= 0.82 +/- 0.15 and Km S.D.= 58.8 +/- 9.0; n= 19). When patients were dichotomized on the basis of their treatment response, responders had kinetic parameters significantly increased (Vmax +/-S.D.= 1.03 +/- 0.26, p< 0.01 and Km +/- S.D.= 71.7 +/- 18.7, p< 0.05, n= 10) compared to controls, whereas non-responders had not (Vmax +/- S.D.= 1.00 +/- 0.33, NS and Km +/- S.D.= 65.7 +/- 10.9, NS, n= 9). At D7, Vmax differed from the one of controls only in the responders (Vmax +/- S.D.= 1.03 +/-0.26, p< 0.01). In addition, the percentage of variation of the individual Vmax values during the first week of treatment was significantly lower in responders than in non-responders (deltaVmax(D7-D0) +/- S.D. in % = 10.7 +/- 6.0 and 22.0 +/- 11. 1, p< 0.05, respectively). At D28, kinetics of L-T3 uptake normalized only in the responders (Vmax +/- S.D.= 0.91 +/- 0.13, NS; Km+/-S.D.= 65.7 +/- 7.4, NS). The results indicate that both RBC L-T3 uptake at the pretreatment level and its change during the first week of fluvoxamine treatment were related to the further clinical response to the antidepressant. RBC L-T3 uptake seems to be a biological correlate of the depressive symptomatology since the disturbances disappear only with the clinical remission.

Effects of experimental hypothyroidism on 5-HT1A, 5-HT2A receptors, 5-HT uptake sites and tryptophan hydroxylase activity in mature rat brain1.

The study was aimed at investigating the repercussions of deficiency in thyroid function with and without thyroid hormone (TH) replacement on the neurochemical entities which underly serotonin (5-HT) neutrotransmission, namely 5-HT1A, 5-HT2A receptors, 5-HT transporter and tryptophan hydroxylase (TPH) in the mature brain. Surgically thyroidectomized male Wistar rats received: (1) an iodine-free diet to produce severe hypothyroidism; (2) hormonal replacement with 15 microgram/kg/day of thyroxine (T4) for 21 days to normalize serum TH levels, or (3) hormonal replacement with 200 microgram/kg/day of T4 for 14 days to produce an excess of circulating THs. Sham-operated rats were used as controls. Neither hypothyroidism nor an excess in serum TH levels affected 3H-8-OH-DPAT binding to 5-HT1A receptors, 3H-citalopram binding to 5-HT transporter and TPH activity in various brain structures indicating that, in the mature brain, the presynaptic entities of 5-HT neurotransmission are resistant to large variations in TH levels. By contrast, hypothyroid rats had a significant decrease in Bmax of 3H-ketanserin binding to cortical 5-HT2A receptors compared to controls. Cortical 3H-ketanserin binding in thyroidectomized rats was normalized after replacement with low-dose T4. Excess serum TH levels in thyroidectomized rats did not produce any changes in cortical 5-HT2A receptors when compared to thyroidectomized rats with normalized TH levels. The present data suggest that the decrease in cortical 5-HT2A receptors is the main neurochemical event underlying the impairing effect of hypothyroidism on 5-HT neurotransmission.

Kinetics of red blood cell T3 uptake in hypothyroidism with or without hormonal replacement, in the rat.

L-triiodothyronine (L-T3) is taken up and accumulated into red blood cells (RBC) by means of a specific carrier-mediated system. The aim of this study was to evaluate the reactivity of this system in relation to induced alterations in thyroid hormone (TH) supply. We investigated the kinetic parameters (Vmax, maximal velocity and Km, Michaelis constant) of washed-RBC L-T3 uptake 1) in thyroidectomized (TXT) rats, 2) in TXT rats administered with low doses of L-T4 (15 microg/kg/day x 14) to restore normal serum TH levels (REPL), 3) in TXT rats administered with high doses of L-T4 (200 microg/kg/day x 14) to achieve a large increase in serum TH levels (HIGH). Serum free T3 and T4 levels were significantly decreased in TXT rats (2.4 and 8.8 fold, respectively), not different in REPL rats and significantly increased in HIGH rats (2.4 and 3 fold, respectively) compared to sham-operated rats (SHAM). Both kinetics of RBC L-T3 uptake were significantly increased in TXT rats (Vmax+/-SE in pmol/min/10(8) cells=235.1+/-11.1, p<0.05 and Km+/-SE in nM=190.1+/-9.0, p<0.05), not different in REPL rats (Vmax=1 84.8+/-7.6 and Km=151.9+/-7.1) and significantly decreased in HIGH rats (Vmax=168.0+/-4.1, p<0.01 and Km=131.9+/-4.6, p<0.01) compared to SHAM rats (Vmax=197.7+/-5.8 and Km=160.9+/-6.1). These results show that kinetics of RBC L-T3 uptake are modified in response to defect or excess in circulating TH levels. Since RBC play likely a role of a buffer system, the changes in carrier-mediated influx of L-T3 could be seen as a compensatory mechanism that counteract the disturbances in the TH availability for the target tissues.

Increase in red blood cell triiodothyronine uptake in untreated unipolar major depressed patients compared to healthy volunteers.

1. Kinetic parameters of red blood cell (RBC) L-triiodothyronine (T3) initial uptake (Vmax, maximal velocity and Km, Michaelis constant) were determined in 34 untreated inpatients suffering from unipolar depression and in 40 healthy volunteers. 2. Both Vmax and Km were significantly increased in depressed patients as compared to controls. The alterations in kinetic parameters were not associated with the severity of depression. 3. Out of the 19 depressed patients who were submitted to TRH test, 7 of them (36%) showed a blunted TRH-induced TSH response associated with a Vmax situated outside the control mean value +/- 1 S.D. 4. The authors found a significant positive correlation between Vmax of RBC L-T3 and L-tryptophan (TRP) uptakes which is in agreement with the assumption that L-T3 and L-TRP share a common carrier system at the erythrocyte level. 5. The results indicate that the uptake of L-T3 by RBC is increased in major depression. These transport perturbations might reflect alterations in the plasmatic metabolism of L-T3. Evaluation of RBC L-T3 uptake could be useful in a best biological characterization of the depressed patients with regard to their thyroid function.

[Hemodynamic effects of intravenous diltiazem after immediate coronary revascularization]. / Effets hémodynamiques du diltiazem intraveineux au décours immédiat d'une revascularisation coronaire.

Perioperative spasm of the internal mammary artery (IMA) may occur after coronary artery bypass surgery. Diltiazem is often used to prevent it. We studied the haemodynamic tolerance of this drug just after coronary artery bypass surgery, using an intravenous injection of 0.3 mg.kg-1 in 2 minutes. Fifteen patients were studied and the injection was performed less than one hour after the arrival of the patient in the intensive care unit. A reduction in systemic arterial blood pressure and a negative chronotropic effect was observed. There was no significant modification of cardiac output. Diltiazem used in that context has no myocardial depressant effect.

[Comparison of vascular effects of magnesium sulfate and nicardipine during extracorporeal circulation]. / Comparaison des effets vasculaires du sulfate de magnésium et de la nicardipine pendant la circulation extracorporelle.

OBJECTIVE: To evaluate the hypothesis that magnesium sulphate (SO4Mg), usually administered for protecting the myocardium and decreasing the rate of arrhythmias in cardiac surgery, was able to control the hypertensive peaks occurring during cardiopulmonary bypass (CPB), as efficiently as nicardipine (N). STUDY DESIGN: Randomized controlled trial. PATIENTS: Forty patients were allocated into two groups when hypertensive peaks occurred during CPB. The patients of the N group were then given nicardipine 0.016 mg.kg-1 and those of the SO4Mg group received magnesium sulphate 50 mg.kg-1. METHODS: Anaesthesia technique was identical and during normothermic CPB the flow remained constant at 2.4 L.min-1, during the 10 min following N or SO4Mg administration. The usual haemodynamic variables were monitored. RESULTS: Both N and SO4Mg decreased significantly the MAP and the SVR over the 9 min following their administration. The decrease was more marked after SO4Mg. As the flow of the pump was unchanged after their injection the decrease can be attributed to the relaxing effect of these agents on the smooth vascular muscles. CONCLUSIONS: SO4Mg permits to treat hypertensive peaks occurring during CPB as efficiently as N. Three grammes of SO4Mg have an hypotensive effect equivalent to that of 1 mg of nicardipine. However repetitive injections of SO4Mg cannot be recommended because of the risk for hypermagnesemia.

[Comparison of effects of aprotinin and tranexamic acid on blood loss in heart surgery]. / Comparaison des effets de l'aprotinine et de l'acide tranexamique sur le saignement en chirurgie cardiaque.

OBJECTIVES: To compare the efficacy of aprotinin (APR) and tranexamic acid (TRA) in reducing blood loss and transfusion requirements after cardiac surgery under extracorporeal circulation (ECC). STUDY DESIGN: Randomized controlled trial. PATIENTS: One hundred and four adults undergoing either coronary artery bypass grafting (CABG) (n = 55), or aortic valve replacement (AVR) (n = 49), allocated into three groups. METHODS: a) APR group (23 CABG and 20 AVR) received aprotinin, 2 x 10(6) KIU (280 mg) after induction, followed by an infusion of 0.5 x 106 KIU.h-1 (70 mg.h-1) until chest closure, with a supplement to the oxygenator prime of 2 x 10(6) KIU; b) TRA group (22 CABG and 19 AVR) received tranexamic acid, 15 mg.kg-1 between the injection of heparin (400 IU.kg-1) and the beginning of ECC, 15 mg.kg-1 after protamin injection (1.3 mg/100 IU of heparin); c) CTR group (10 CABG and 10 AVR), the control group, was not treated with an antifibrinolytic agent. The amount of blood collected from the chest tube drainage was measured at admission to ICU, as well as 4, 8 and 18 h after the insertion of drains and at the time of their removal. Packed red cells where given when the haematocrit was under 20% during ECC, 25% at the end of surgery and 30% after extubation. RESULTS: The blood loss was lower in APR group (834 +/- 448 mL) than in TRA group (1015 +/- 409 mL) (P = 0.009), and in CTR group (1416 +/- 559 ML) (P = 0.004). The rates of transfused patients in groups APR, ATR and CTR were 35, 37 and 60% respectively and the numbers of units administered per patient were 0.8, 0.8 and 1.7 respectively. In AVR cases, APR and TRA had a similar efficacy. In CABG cases, only aprotinin decreased postoperative bleeding. However there was no difference between APR and TRA concerning the transfusion requirements. In CABG cases the ECC was of shorter duration and blood loss was 1127 +/- 540 mL vs 894 +/- 422 mL in AVR cases (P = 0.03). CONCLUSIONS: Both APR and TRA decrease blood loss. APR is more efficient after CABG than TRA as far as blood loss is concerned, whereas the transfusion requirements are similar. As APR is about 100 times more expensive and carries a risk for allergic reactions, its use in a high dose regimen is only recommended for reoperations, in patients treated with salicylates and in case of sepsis.

[Cardiac surgery in aged patients; immediate and medium-term results in 100 patients over 75 years of age]. / Chirurgie cardiaque chez les patients âgés; résultats immédiats et à moyen terme chez 100 patients âgés de 75 ans et plus.

With improved operative technique and postoperative care, progressively older patients are being referred for cardiac surgery. One hundred out of 633 patients operated between September 1990 and December 1992, were over 75 years of age (Group I). These patients were compared with the last 100 patients under 75 years of age (Group II). Both groups were operated by the same surgical team with the same anaesthetic, cardiopulmonary bypass and myocardial protection techniques. The average age of the groups was 79.5 +/- 3.1 and 62.1 +/- 9.2 years, respectively. The procedures performed were: myocardial revascularisation (Group I, 28 cases; Group II, 59 cases), aortic valve surgery alone or associated with coronary bypass (56 and 22 cases respectively), and mitral valve surgery alone or associated with another procedure (11 and 12 cases). There were no significant differences between the two groups with respect to true low output state, the duration of mechanical ventilation and of intensive care and hospital stay. On the other hand, there were significant differences in: the number of blood transfusions (44 cases versus 20, p < 0.001), the occurrence of atrial fibrillation (52 cases versus 29, p < 0.001) and neuropsychiatric disturbances (27 cases versus 5, p < 0.0001). There were no cases of mediastinitis in either group. The hospital mortality was 6% in Group I and 5% in Group II (NS). The medium-term mortality after an interval of 5 to 32 months in the over 75 age group was 7 cases, including 4 cases of cerebrovascular accident. An enquiry was performed in the 87 survivors of Group I.(ABSTRACT TRUNCATED AT 250 WORDS)

[Retrograde cerebral perfusion for replacement of the aortic arch. Apropos of a case]. / Perfusion cérébrale rétrograde pour remplacement de la crosse aortique. A propos d'un cas.

The authors report a case of cerebral protection with retrograde cerebral perfusion during aortic arch surgery. The duration of retrograde cerebral perfusion and the favorable neurological outcome seem to confirm the promising results of this technique developed in Japan.