Accessory liver lobes: anatomical description and clinical implications

Accessory liver lobes are a rare condition and appear to be due to excessive development of the liver. The presence of an accessory hepatic lobe is often diagnosed incidentally and sometimes revealed if it develops torsion, especially in pedunculated forms. In most cases, the accessory lobe is located below the liver, i.e., infrahepatic. Riedel's lobe is the best-known example of an accessory lobe, corresponding to hypertrophy of segments V and VI. While accessories lobes can simulate tumors, there have also been reports of hepatocellular tumor(s) that developed in these accessory lobes. Based on a review of the literature, this update focuses on accessory hepatic lobes.

Randomized clinical trial of ischaemic preconditioning in major liver resection with intermittent Pringle manoeuvre

BACKGROUND

Vascular inflow occlusion is effective in avoiding excessive blood loss during hepatic parenchymal transection but may cause ischaemic damage to the remnant liver. Intermittent portal triad clamping (IPTC) is superior to continuous hepatic pedicle clamping as it avoids severe ischaemia-reperfusion (IR) injury in the liver remnant. Ischaemic preconditioning (IPC) before continuous Pringle manoeuvre may protect against IR during major liver resection.

METHODS

This RCT assessed the impact of IPC in major liver resection with intermittent vascular inflow occlusion. Patients undergoing major liver resection with intermittent vascular inflow occlusion were randomized, during surgery, to receive IPC (10 min inflow occlusion followed by 10 min reperfusion) or no IPC (control group). Data analysis was on an intention-to-treat basis. The primary endpoint was serum alanine aminotransferase (ALT) level on the day after surgery.

RESULTS

Eighty four patients were enrolled and randomized to IPC (n = 41) and no IPC (n = 43). The groups were comparable in terms of demographic data, preoperative American Society of Anesthesiologists grade and extent of liver resection. Intraoperative morbidity and postoperative outcomes were also similar. ALT levels on the day after operation were not decreased by IPC (mean(s.d.) 537·6(358·5) versus 525·0(400·6) units/ml in IPC and control group respectively; P = 0·881). Liver biochemistry tests in the week after operation showed the same pattern in both groups.

CONCLUSION

IPC did not reduce liver damage in patients undergoing major liver resection with IPTC.

REGISTRATION NUMBER

NCT00908245 (http://www.clinicaltrials.gov).

Reduced-dose tacrolimus with mycophenolate mofetil vs. standard-dose tacrolimus in liver transplantation: a randomized study

We conducted a multicenter randomized study in liver transplantation to compare standard-dose tacrolimus to reduced-dose tacrolimus with mycophenolate mofetil to reduce the occurrence of tacrolimus side effects. Two primary outcomes (censored criteria) were monitored during 48 weeks post-transplantation: occurrence of renal dysfunction or arterial hypertension or diabetes (evaluating benefit) and occurrence of acute graft rejection (evaluating risk). Interim analyses were performed every 40 patients to stop the study in the case of increased risk of graft rejection. One hundred and ninety-five patients (control: 100; experimental: 95) had been included when the study was stopped. Acute graft rejection occurred in 46 (46%) and 28 (30%) patients in control and experimental groups, respectively (HR = 0.59; 95% CI: [0.37-0.94]; p = 0.024). Renal dysfunction or arterial hypertension or diabetes occurred in 80 (80%) and 61 (64%) patients in control and experimental groups, respectively (HR = 0.68; 95% CI: [0.49-0.95]; p = 0.021). Renal dysfunction occurred in 42 (42%) and 23 (24%) patients in control and experimental groups, respectively (HR = 0.49; 95% CI: [0.29-0.81]; p = 0.004). Leucopoenia (p = 0.001), thrombocytopenia (p = 0.017) and diarrhea (p = 0.002) occurred more frequently in the experimental group. Reduced-dose tacrolimus with mycophenolate mofetil reduces the occurrence of renal dysfunction and the risk of graft rejection. This immunosuppressive regimen could replace full-dose tacrolimus in adult liver transplantation.

Development of a Bayesian estimator for the therapeutic drug monitoring of mycophenolate mofetil in children with idiopathic nephrotic syndrome

The use of mycophenolate mofetil (MMF) in children with idiopathic nephrotic syndrome (INS) is increasing. However, the clinical benefit of its monitoring has been scarcely studied, and little is known about its pharmacokinetics in this context. The objectives of the present study were: (i) to study and model the pharmacokinetics of mycophenolic acid (MPA; the active moiety of MMF) in paediatric patients with INS given MMF, at all stages of the disease; (ii) to develop a Bayesian estimator (MAP-BE) for individual inter-dose area under the concentration-time curve (AUC) prediction in this population, using a limited blood sampling strategy (LSS). Full-pharmacokinetic (PK) profiles of MPA collected in paediatric inpatients with INS already treated with a maintenance immunosuppressive therapy based on MMF (with no calcineurin inhibitors; CNI) were studied. A classical iterative two-stage (ITS) method was applied to model the data and develop MAP-BEs using a one-compartment open model where the absorption is described by a double gamma law allowing the description of a potential enterohepatic recirculation. The performance of the MAP-BE developed for individual exposure assessment was evaluated by the bias and precision of predicted AUCs with respect to measured, trapezoidal AUCs (reference value), and by the proportion of predicted AUCs with absolute error >20%. These PK tools were tested in an independent group of patients. Sixty PK profiles of MPA from children receiving MMF in association to corticosteroids or given alone were included in the study. Forty-five of these PK profiles were used to develop a PK model and a MAP-BE, and 15 for their validation. In the building group, the PK model fitted accurately the PK profiles of MPA: mean residual error of modelled vs. reference AUC was m±SD=-0.015±0.092 (range: -0.153 to 0.204). The MAP-BE which allowed the estimation of MPA AUC on the basis of a 20 min-60 min-180 min LSS was then developed. In the independent group of patients, its mean residual error vs. reference AUCs was m±SD=-0.036±0.145 (range: -0.205 to 0.189). Thus, a PK model and its derived MAP-BE for MMF (without any associated CNI) when given to children with INS have been developed. Clinical trials using these PK tools could test the potential impact of the therapeutic drug monitoring of MMF based on the AUC on the clinical evolution of INS.

C4d: a marker for hepatic transplant rejection

BACKGROUND

Acute rejection is still a common complication of hepatic transplantation. The diagnosis, based on the histological examination of the graft, may be difficult to confirm in the setting of combined hepatitis C virus infection. The presence of C4d in the portal capillaries could facilitate differentiation between acute rejection and relapsed hepatitis C. The deposit of C4d provides evidence of activation of humoral immunity. To attempt to confirm this hypothesis, we searched for the presence of C4d in posttransplant hepatic biopsies.

METHODS

Thirty-six biopsies from 34 patients were analyzed retrospectively. The samples had been requested for one of the following reasons: suspected rejection, relapsed hepatitis C infection, or systematic check-up 1 year after the transplant.

RESULTS

C4d expression was common in biopsies classified as acute rejection (33%) and chronic rejection (100%). C4d was never detected in the event of recurrent hepatitis C infection without rejection.

CONCLUSION

These results, which are comparable to recently published data, give credence to the theory that C4d could be used as a marker for rejection following hepatic transplantation.

Improved Liver Function and Decreased Hepatitis C Viral Load After Tacrolimus Was Replaced by Cyclosporine

Potential antiviral properties of cyclosporine against hepatitis C virus have been highlighted in several publications. Therefore, we investigated the effect of a switch from tacrolimus to cyclosporine in a liver transplant recipient with recurrent hepatitis C who did not respond to antiviral therapy. The patient received a liver transplant for hepatitis C cirrhosis. Initial immunosuppressive treatment was based on tacrolimus. Because of viral activity, a combined therapy was initiated 20 months later including interferon and ribavirine. Then, due to a lack of virological and biochemical response, tacrolimus was replaced by cyclosporine (Neoral), while maintaining the same antiviral therapy. Decreases in the viral load and transaminases levels were observed.

Technique du prélèvement « multiorganes » : cœur–foie–reins

The goal of multiple organ procurement is to retrieve intact organs fully. This goal can only be reached if the organ dissection and preservation are optimal.

[Roux-en-Y limb anastomosed to small biliary duct]

We describe a simple and safe technique of cholédocho-jejunostomy using a Roux-en-Y jéjunal limb, to repair immediately biliary tract injuries, even when the conduits are thin.

Production and metabolism of serotonin (5-HT) by the human adrenal cortex: paracrine stimulation of aldosterone secretion by 5-HT

In the human adrenal cortex, serotonin (5-HT) is contained in mast-like cells, and we have shown that 5-HT stimulates aldosterone secretion, suggesting that 5-HT may control glomerulosa cells through a paracrine mechanism. Concurrently, the presence of 5-hydroxyindolacetic acid in human adrenocortical extracts indicates that 5-HT may be metabolized after local release by mast cells. The aim of the present study was to investigate in vitro the production and metabolism of 5-HT by the human adrenal cortex. Perifused adrenal slices released spontaneously detectable amounts of 5-HT (0.74 +/- 0.38 fmol/mg wet tissue.min). The mast cell-depleting drug compound 48/80 induced a burst of 5-HT secretion followed by a gradual increase in aldosterone production. Administration of the specific 5-HT(4) receptor antagonist GR 113808 (10(-6) M) did not affect compound 48/80-induced 5-HT release but abolished the stimulatory effect of compound 48/80 on aldosterone secretion, indicating that 5-HT released locally is responsible for a paracrine control of steroidogenesis. Incubation of cells from the human adrenal cortex with 5-HT (10(-5) M) provoked the formation of the 5-HT metabolite 5-hydroxytryptophol. The type A monoamine oxidase (MAO) inhibitor clorgyline (10(-6) M) suppressed the metabolism of 5-HT into 5-hydroxytryptophol. Immunocytochemical staining of cultured cells revealed the presence of a subpopulation of MAO-A-positive cells. Double labeling with an antiserum against chromogranin A showed that MAO-A was actually contained in chromaffin cells. Similarly, immunohistochemical staining of adrenal slices showed that MAO-A was expressed in chromaffin cells located both in the medulla and in intracortical rays. In conclusion, the present study shows that, in the human adrenal cortex, 5-HT, released by mast-cells, may stimulate aldosterone secretion in a paracrine manner. Our data also indicate that 5-HT is metabolized by MAO-A located in intracortical chromaffin cells.

Effects of hypothermic machine perfusion on rat liver function depending on the route of perfusion

BACKGROUND AND METHODS

The aim of this study was to evaluate the efficacy of hypothermic machine perfusion (HMP) to preserve rat livers according to the route of perfusion, i.e., via portal vein, hepatic veins (retrograde), or hepatic artery. Livers were preserved for 24 or 48 hr by simple cold storage (SCS) or by HMP. Preservation solution was supplemented with (HMP) or without (SCS) hydroxyethyl starch. After preservation, grafts were reperfused for 2 hr with an oxygenated Krebs-Henseleit bicarbonate buffer.

RESULTS

After 24 hr of preservation, total glutathione concentrations in HMP livers were similar (1287+/-37, 1418+/-118, and 1471+/-62 nmol/g in hepatic artery, portal vein, and hepatic vein HMP livers, respectively) and higher than in the SCS (833+/-118 nmol/g, P<0.05) group. These higher total glutathione values were due to higher reduced glutathione concentrations. ATP concentrations in the liver tissue were similar in HMP groups (0.75+/-0.4, 0.64+/-0.1, and 0.77+/-0.1 micromol/g in hepatic artery, portal vein, and hepatic vein HMP livers, respectively) and higher than in SCS (0.32+/-0.06 micromol/g, P<0.05). After 2 hr of normothermic reperfusion, bile production in the HMP portal and HMP retrograde groups were similar (391+/-29 ml and 372+/-25 ml) and higher than in the HMP artery or SCS groups (275+/-25 ml and 277+/-32 ml, respectively; P<0.05). Aspartate transaminase, alanine transaminase, lactate dehydrogenase, and purine nucleoside phosphorylase release into the perfusate of HMP portal and HMP retrograde perfused livers was similar and significantly lower compared to the HMP artery and SCS groups. At the end of reperfusion, no statistical differences were found for glutathione concentration and energetic reserves in the livers of each group. After 48 hr of preservation, livers from the HMP portal and HMP retrograde groups did significantly better than livers from the HMP artery or SCS groups.

CONCLUSIONS

This study confirms the superiority of HMP over SCS to preserve the liver graft. It shows that retrograde perfusion is similar to PV perfusion and that perfusion by HA is less beneficial.

Divergent effects of verapamil and amlodipine at rest and during exercise

OBJECTIVE

To evaluate, in healthy volunteers, the effects of acute administration of two calcium antagonists with different pharmacological profiles, verapamil and amlodipine, on haemodynamics at rest and during exercise.

SUBJECTS AND METHODS

Six healthy volunteers (aged 20-29 years) were randomly assigned to receive single oral doses of amlodipine (5 mg), slow-release verapamil (240 mg) or a placebo during a double-blind cross-over study. Systolic (SAP), diastolic and mean arterial pressures (measured using a cuff sphygmomanometer), heart rate (HR), cardiac index (CI, bioimpedance), rate-pressure product (SAP x HR), and noradrenaline and adrenaline plasma levels were measured at rest before drug administration, and at rest and during graded bicycle exercise (steps of 50, 100 and 150 W during 3, 3 and 4 min, respectively) started 3 h after drug administration.

RESULTS

At rest arterial pressure, HR, rate-pressure product and catecholamine plasma levels did not change after verapamil or amlodipine administration, whereas CI significantly decreased after verapamil (from 3.9 +/- 0.4 to 3.3 +/- 0.4 l/min per m2) but not after amlodipine (3.9 +/- 0.3 and 4.1 +/- 0.5 l/m per m2) administration. During exercise the increases in SAP and HR were slightly but not significantly higher after amlodipine than after verapamil administration, rate-pressure product and CI were higher after amlodipine (22 +/- 1 x 10(3) mmHg x beats/min and 13 +/- 2 l/min per m2, respectively) than after verapamil (20 +/- 1 x 10(3) mmHg x beats/min and 10 +/- 2 l/min per m2, respectively) administration. Plasma levels of noradrenaline and adrenaline were similar at rest after each treatment and were slightly more increased after amlodipine administration during exercise.

CONCLUSIONS

In contrast to amlodipine, verapamil induced a slight myocardial depressive effect at rest and did not potentiate the myocardial effects of the sympathetic stimulation induced by exercise. The myocardial action of verapamil is such as to induce some decrease in myocardial oxygen demand, both at rest and during exercise.

Role of endogenous endothelin in chronic heart failure: effect of long-term treatment with an endothelin antagonist on survival, hemodynamics, and cardiac remodeling

BACKGROUND

Plasma levels of the vasoconstrictor peptide endothelin (ET) are increased in chronic heart failure (CHF), and ET levels are a major predictor of mortality in this disease. Thus, ET may play a deleterious role in CHF. The purpose of this study was to assess the effects of chronic treatment with the ET receptor antagonist bosentan in a rat model of CHF.

METHODS AND RESULTS

Rats were subjected to coronary artery ligation and were treated for 2 or 9 months with placebo or bosentan (30 or 100 mg x kg(-1) x d(-1)). Bosentan 100 mg x kg(-1) markedly increased survival (after 9 months: untreated, 47%; bosentan, 65%; P<.01). Throughout the 9-month treatment period, bosentan significantly reduced arterial pressure and heart rate. After 2 or 9 months of treatment, the ET antagonist reduced central venous pressure and left ventricular (LV) end-diastolic pressure as well as plasma catecholamines, urinary cGMP, and LV ventricular collagen density. Bosentan also reduced LV dilatation (evidenced at 2 months by a shift in the pressure/volume relationship ex vivo). Echocardiographic studies performed after 2 months showed that the ET antagonist reduced hypertrophy and increased contractility of the noninfarcted LV wall. The lower dose of bosentan (30 mg x kg(-1)), which had no major hemodynamic or structural effects, also had no effect on survival.

CONCLUSIONS

Long-term treatment with an ET antagonist markedly increases survival in this rat model of CHF. This increase in survival is associated with decreases in both preload and afterload and an increase in cardiac output as well as decreased LV hypertrophy, LV dilatation, and cardiac fibrosis. Thus, chronic treatment with ET antagonists such as bosentan might be beneficial in human CHF and might increase long-term survival in this disease.

Increased survival after long-term treatment with mibefradil, a selective T-channel calcium antagonist, in heart failure

OBJECTIVES

We sought to investigate the effects of mibefradil on survival, hemodynamic variables and cardiac remodeling in a rat model of chronic heart failure (HF) and to compare these effects with those of the angiotensin-converting enzyme (ACE) inhibitor cilazapril.

BACKGROUND

The use of calcium channel blocking agents in chronic HF has been disappointing. Most studies have shown that these drugs have either no or even detrimental effects due in part to the negative inotropic effects they induce. Mibefradil is a calcium channel blocker that selectively blocks T channels and displays moderately negative inotropic properties only at high doses. Because T channels are upregulated in the hypertrophied heart and could mediate hypertrophic signals and increase arrhythmogenicity, blockade of these channels might be beneficial in chronic HF.

METHODS

Rats were subjected to coronary artery ligation and 9 months of treatment with mibefradil (15 mg/kg body weight per day) or cilazapril (10 mg/kg per day) or no treatment. Survival and systolic blood pressure were assessed over the 9-month treatment period, after which cardiac hemodynamic variables and structure were determined.

RESULTS

Mibefradil increased survival rate to the same extent as cilazapril (71% for mibefradil vs. 75% for cilazapril and 44% for no treatment). Mibefradil decreased systolic blood pressure, although to a lesser extent than cilazapril. Both treatments decreased left ventricular (LV) end-diastolic and central venous pressures, without any change in the first derivative of LV pressure over time or heart rate. Mibefradil decreased LV weight (although less than cilazapril) without affecting right ventricular weight. Finally, both drugs normalized LV collagen density.

CONCLUSIONS

Mibefradil in a rat model improved survival to the same extent as an ACE inhibitor, without impairing LV function, and was associated with a reduction in LV weight and fibrosis. Thus, mibefradil might be beneficial in the treatment of chronic HF.

Response of large and small vessels to alpha and beta adrenoceptor stimulation in heart failure: effect of angiotensin converting enzyme inhibition

The increased sympathetic drive in chronic heart failure (CHF) might provoke vascular adrenoceptor desensitization, which, together with endothelial dysfunction, could contribute to the altered vasomotor tone seen in CHF. We investigated 1) whether CHF alters the responses mediated by alpha and beta adrenoceptors in small and large peripheral arteries, and 2) the effect of angiotensin-converting enzyme (ACE) inhibition. Rats with CHF (coronary artery ligation) were treated with placebo or the ACE inhibitor lisinopril (10 mg/kg/d) starting 7 days after ligation. Responses to phenylephrine (alpha 1 agonist), salbutamol (beta 2 agonist) as well as acetylcholine (endothelium-dependent), were assessed after 3 months in isolated and pressurized segments of the abdominal aorta, the femoral and the mesenteric arteries. In animals with hemodynamic signs of CHF, neither the vasoconstrictor responses to phenylephrine nor the vasodilator response to salbutamol were affected. In contrast, the dilator response to acetylcholine of both small arteries, but not that of the aorta, was impaired. Furthermore, CHF did not modify vessel structure. While lisinopril did not modify the responses to adrenergic agonists, it normalized the response to acetylcholine. Furthermore, ACE inhibition reduced vascular media cross sectional area and collagen density. Thus, the unchanged arterial responsiveness to adrenoceptor agonists does not indicate any vascular adrenoceptor desensitization, while endothelial dependent vasodilation of small arteries is impaired in CHF. ACE inhibition does not modify the response to adrenergic stimuli, prevents endothelial dysfunction and induces both cardiac and vascular remodeling, which probably contribute to the effect ACE inhibitors have on exercise tolerance and survival.

Peripheral artery structure and endothelial function in heart failure: effect of ACE inhibition

Chronic heart failure (CHF) induces peripheral vasoconstriction and impairs endothelium-dependent relaxation of large arteries. We investigated in a rat model of CHF (coronary artery ligation) 1) whether endothelial dysfunction also exists in resistance arteries, 2) whether this is associated with vascular morphological changes, and 3) the effect of angiotensin-converting enzyme (ACE) inhibition on these parameters. After 1 mo or 1 yr, CHF reduced the vasodilatory response to acetylcholine of isolated, perfused femoral and mesenteric artery segments. This impairment was more marked in femoral than in mesenteric arteries. However, CHF did not induce any arterial remodeling. Chronic treatment with the ACE inhibitor perindopril improved the response to acetylcholine and reduced media cross-sectional area and collagen density. Thus at the level of small peripheral arteries, CHF induces an endothelial dysfunction but does not affect vascular structure. ACE inhibition prevents the CHF-induced endothelial dysfunction and induces vascular remodeling. These changes could contribute to the observed beneficial effects of ACE inhibitors on hemodynamics and survival in CHF.

Simple high-performance liquid chromatographic method for the quantitation of 5-fluorouracil in human plasma

A simple, rapid, specific and sensitive high-performance liquid chromatography method has been developed for quantitation of 5-fluorouracil (5-FU) in human plasma. The method involves deproteinization of a small sample volume of plasma (150 microliters) followed by HPLC on a cation-exchange resin column, Aminex HPX-87H (300 x 7.8 mm I.D.), preceded by a similar guard cartridge with UV detection at 265 nm. This method allows a good separation of 5-FU with a retention time of 24 min and a detection limit at 25 ng/ml. The calibration curve was linear from 25 to 2000 ng/ml. The coefficient of variation was < or = 4.4% for within-day reproducibility and < or = 9.5% for day-to-day reproducibility.

Liver grafts can be preserved overnight

The introduction of University of Wisconsin solution has made liver transplantation a semi-elective procedure. However, many studies have suggested that cold storage must not exceed 12 hours to avoid ischemic-type biliary complications, to reduce the incidence of primary nonfunction and to improve graft and patient survival. The aim of this study was to compare the function of livers transplanted as soon as possible after the liver was harvested and those preserved overnight. Over a 42-month period, we studied 133 elective orthotopic liver transplantation procedures. When cold ischemia started after 6 PM, patients underwent transplantation the following morning (group A), whereas the remainder underwent transplantation immediately (group B). Cold ischemia lasted 13.7 hours and 9.5 hours in groups A and B, respectively (P < .001). The two groups were comparable in terms of initial and late biochemical liver function, the rates of primary nonfunction (6.5% in group A, 6.8% in group B), acute rejection (45.6% in group A, 45.7% in group B), and vascular and infectious complications. No ischemic-type biliary complications were observed. Graft and patient survival were similar in both groups (72.4% v 75.4% and 72.9% v 75.8% in groups A and B, respectively). These results suggest that having taken a cut off at 6 PM to divide the groups into those that underwent transplantation consecutively and those deferred to the morning, the difference between the two groups in terms of storage is relatively modest. Elective liver transplantation can be performed after overnight graft storage without increasing short-term or long-term morbidity or mortality rates.

Vascular and myocardial protective effects of converting enzyme inhibition in experimental heart failure

Systemic vasoconstriction due to stimulation of the sympathetic and renin-angiotensin-aldosterone systems is a hallmark of heart failure and this is accompanied by impaired endothelium-dependent relaxations at the level of large arteries. This study investigated, in a rat model of heart failure, whether such an endothelial dysfunction also exists at the level of the resistance artery, and whether this is associated with morphologic changes, as well as the effects of chronic treatment with the angiotensin-converting enzyme inhibitor perindopril (2 mg/kg/day). After 12 months, arterial pressure, left ventricular (LV) end diastolic pressure (LVEDP), and LV dP/dt were measured in anesthetized rats. Responses to acetylcholine and nitroprusside were determined in isolated and perfused mesenteric artery segments (diameter: 280 +/- 15 microns). After fixation, vessel diameter, media cross-sectional area, and media collagen and elastin densities were measured by image analysis. After 12 months, untreated rats showed signs of heart failure, i.e., reduced LV dP/dt, and increased LVEDP, heart weight/body weight, LV cavity circumference, and myocardial collagen density. In mesenteric vessels the endothelium-dependent vasodilator response to acetylcholine was impaired, whereas the response to the nitric oxide donor nitroprusside was unaffected. Heart failure did not affect vascular morphological parameters. Perindopril decreased blood pressure and LVEDP without any modification of LV dP/dt, and prevented cardiac remodeling. At the vascular level, perindopril improved the response to acetylcholine and reduced media cross-sectional area and collagen density without affecting internal vessel diameter or elastin density. Thus, heart failure decreases endothelium-dependent vasodilator response to acetylcholine without modification of vessel structure.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of metformin accumulation in metformin-associated lactic acidosis

OBJECTIVE

To investigate the role of metformin accumulation in the pathophysiology of metformin-associated lactic acidosis.

RESEARCH DESIGN AND METHODS

We used high-performance liquid chromatography to measure plasma metformin concentrations in 14 patients who experienced lactic acidosis (pH < 7.35 and lactate concentration 5 > mmol/l) while receiving chronic metformin treatment. Their treatment was generally based on alkalinization and dialysis therapy.

RESULTS

Clinical shock and/or evidence of tissue hypoxia was found in all patients with the exception of one who had a nonsteroidal anti-inflammatory drug-induced anuria. Ten patients had significant metformin accumulation (plasma metformin concentrations 4.1-84.9 mg/l, normal value 0.6 +/- 0.5 mg/l before drug intake), generally because of failure to withdraw metformin despite intercurrent pathological conditions affecting its renal elimination (serum creatinine concentrations ranging from 269 to 1,091 mumol/l). There was no metformin accumulation (plasma metformin 0.03-0.7 mg/l) in the four other patients, who had less severe renal failure (serum creatinine 140-349 mumol/l). The severity of the patient's general condition did not predict early hospital mortality (death before discharge from the intensive care unit) even in patients in shock. Whereas it was high in those without metformin accumulation (only 1 of 4 patients recovered), early hospital mortality was low in the 10 patients with metformin accumulation and was not related to its extent (3 patients died with end-stage hepatic failure or cardiac failure). Correlation studies showed a positive correlation between serum creatinine and plasma metformin and between plasma metformin and arterial lactate but, for the latter correlation, only in patients with metformin accumulation.

CONCLUSION

Metformin-associated lactic acidosis is not necessarily due to metformin accumulation; true type B (aerobic) lactic acidosis, i.e., without an apparent associated hypoxic factor, seems exceptional. Neither the severity of the clinical picture nor the degree of metformin accumulation predicted survival; rather, the prognosis was dependent upon the severity of the associated pathological conditions.

Prevention of endothelial dysfunction in small and large arteries in a model of chronic heart failure. Effect of angiotensin converting enzyme inhibition

Chronic heart failure (CHF) impairs endothelium-dependent vasodilatation of large conductance arteries. We investigated whether a similar reduction also occurs in small arteries, and whether such a reduction can be prevented by the angiotensin converting enzyme inhibitor perindopril (P) in a rat model of CHF (left coronary artery ligation). After 1 month treatment with placebo or P (2 mg/kg/day), rats were anesthetized and arterial pressure, left ventricular end-diastolic pressure, and central venous pressure were measured with a micromanometer. Segments of aorta and mesenteric artery (mean diameter, 281 +/- 8 microns) were then isolated, cannulated, and perfused at constant pressure using an arteriograph. Responses to increasing concentrations of acetylcholine (Ach), nitroprusside, and to 10(-4) mol/L NG-nitro-L-arginine methyl ester (L-NAME) were studied after preconstriction by phenylephrine. Heart failure resulted in a decrease in systolic and diastolic pressures, an increase in left ventricular end-diastolic and central venous pressures, and a significant depression of Ach-induced dilatation of the mesenteric artery (maximal dilatation, from 90 +/- 4% to 63 +/- 4%, P < .05) but not of the aorta (from 56 +/- 8% to 45 +/- 5%, NS) without any modification in the endothelium-independent vasodilatation induced by nitroprusside. In the group treated by the angiotensin converting enzyme (ACE) inhibitor perindopril, systolic and diastolic pressures were slightly decreased, whereas left ventricular end diastolic, central venous pressures, and the endothelium-dependent vasodilating response to Ach were normalized. Responses to L-NAME were not affected by CHF or perindopril. Perindopril also decreased hypertrophy, as evidenced by a significantly lower heart weight in treated rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma 5-fluorouracil and alpha-fluoro-beta-alanin accumulation in lung cancer patients treated with continuous infusion of cisplatin and 5-fluorouracil

This study was undertaken to investigate the day-to-day pharmacokinetic variability of 5-fluorouracil (5FU) given as a continuous i.v. infusion concomitantly with cisplatin. Ten lung cancer patients were investigated during the first course of chemotherapy. All patients had advanced, previously untreated, inoperable non-small-cell lung cancer. They received continuous infusions of cisplatin given at 100 mg/m2 over 5 days and of 5FU given at 1 g/m2 daily from day 2 to day 5. Both drugs were infused i.v. for 24 h/day at a constant rate with a volumetric pump. Blood samples were drawn from day 2 to day 5, every 4 h from 8 a.m. to 8 p.m. and every 2 h during the night (8 p.m. to 8 a.m.). Plasma 5FU and FBAL concentrations were determined simultaneously by gas chromatography-mass spectrometry. Plasma 5FU concentrations varied widely over the 4-day treatment course for each patient. Despite continuous constant-rate 5FU administration, plasma 5FU concentrations were significantly lower between 8 a.m. and 8 p.m. than during the night. Mean plasma concentrations of 5FU and FBAL increased significantly from the 1st day (0.42 and 1.19 micrograms/ml for 5FU and FBAL, respectively) to the 4th day of 5FU infusion (0.67 and 1.78 micrograms/ml for 5FU and FBAL, respectively). Further study is warranted to elucidate the mechanisms of the observed increase in plasma 5FU concentrations as well as its relationship with cisplatin coadministration and to assess the clinical relevance of this plasma 5FU accumulation.

Platelets 3H 5-HT uptake in descendants from alcoholic patients: a potential risk factor for alcohol dependence?

We studied platelet 3H-serotonin uptake in 32 former alcoholics, withdrawn for from 1 month to 22 years, in their descendants (21.7 +/- 1.6 years old, n = 17; 10.9 +/- 0.7 years old; n = 19), and in respective control groups, paired in age and sex. All of the alcoholics presented high 3H-serotonin uptake (Vmax = 10.88 +/- 4.23 pmoles/10(8)pl/30 sec., vs. 0.93 +/- 0.15 pmole/10(8)pl/30 sec. Their descendants also showed high platelet serotonin uptake: 3.94 +/- 1.44 pmoles/10(8)pl/30 sec., vs. 0.93 +/- 0.15 pmoles/10(8)pl/30 sec. for adult descendants, and 5.99 +/- 2.23 vs. 0.84 +/- 0.15 pmole/10(8)pl/30 sec. for young descendants. All subjects were free of alcoholisation (biological parameters studied were blood ethanol concentration, gamma glutamyl transferase and mean corpuscular volume), and dependence of former alcoholics was evaluate by using, a posteriori, the CAGE test. In descendants, 28% of the subjects have Vmax values higher than the highest of the control group. Alcohol, in vitro, (54 mM) did not affect serotonin uptake in any group. These results indicate that in descendants of alcoholics, platelet serotonin uptake is altered, without modification of sensitivity to ethanol. The genetic basis of alcohol dependence could be linked with the platelet serotonin transport.

Tianeptine, a specific serotonin uptake enhancer, decreases ethanol intake in rats

The effect on ethanol intake of the selective 5-HT uptake enhancer tianeptine was examined in rats and compared with that of fluoxetine, a specific 5-HT uptake inhibitor. Both treatments significantly decreased ethanol intake (54% by tianeptine and 57% by fluoxetine). Fluoxetine also decreased food intake whereas tianeptine did not. Body weight was decreased by 12.5% in fluoxetine-treated rats but was not modified by tianeptine. It is proposed that tianeptine has a specific action on ethanol intake, possibly related to its effect on serotonin function.

Ethanol intake and 3H-serotonin uptake I: A study in Fawn-Hooded rats

Ethanol intake and synaptosomal 3H-serotonin uptake were studied in male Fawn-Hooded and Sprague-Dawley rats. Fawn-Hooded rats consumed more alcohol and more water than Sprague-Dawley rats. Plasma alcohol levels of Sprague-Dawley rats were not detectable but were about 5 mg/dl in Fawn-Hooded rats. Ethanol intake increased the Vmax of serotonin uptake in Fawn-Hooded rats in hippocampus and cortex, but not in thalamus. In Fawn-Hooded rats, serotonin uptake (Vmax) was higher than in Sprague-Dawley rats cortex. Ethanol intake reduced the Vmax of serotonin uptake in Fawn-Hooded rats in hippocampus and cortex. In cortex, the carrier affinity for serotonin was increased in alcoholized Fawn-Hooded rats. These results indicate that synaptosomal 3H-serotonin uptake is affected by ethanol intake. In Fawn-Hooded rats, high ethanol consumption is associated with high serotonin uptake. In rats presenting high serotonin uptake, alcoholisation reduces 3H-serotonin internalisation in synaptosomes, indicating a specific sensitivity to alcohol intake of serotonin uptake system.

[Rett syndrome. A report of fifteen cases]

In its typical form, Rett syndrome is characterized by the development, towards the end of the first year of life, of neurologic abnormalities in a formerly healthy girl. Our analysis of 13 observations of "classical" Rett syndrome shows that the most common findings include cognitive regression, autistic behavior, hypotonia, apraxia, and very suggestive stereotyped movements. Two other cases emphasize the problems raised by mild, atypical or incomplete forms. At present, there is no biological or morphological marker for this syndrome whose pathophysiology is unknown. Increased levels of beta-endorphins in the cerebrospinal fluid may prove to be a marker and suggests therapeutic possibilities.