The reassertion profiles of long acting ß2-adrenoceptor agonists in the guinea pig isolated trachea and human recombinant ß2-adrenoceptor.

Long acting ß(2)-adrenoceptor agonists as exemplified by salmeterol and formoterol, exhibit reassertion behaviour in isolated airway preparations. This phenomenon is the inhibition of relaxation by a ß(2)-antagonist (e.g. sotalol), followed by the re-establishment of the relaxation when all drugs have been washed out and in the absence of any further agonist addition to the bathing solution. In this study we have compared the reassertion behaviour of salmeterol and formoterol with the new long acting ß(2)-adrenoceptor agonists indacaterol, carmoterol and three Pfizer agonists (PF610,355, PF613,322, UK503590) in the guinea pig isolated trachea and in a novel assay developed in CHO cells expressing the recombinant human ß(2)-adrenoceptor. The results obtained can be divided into two groups: salmeterol-like (persistent duration of action following agonist removal--coupled with reassertion behaviour), as exemplified by indacaterol, PF610,355, PF613,322 and UK503,590 and, formoterol-like (short duration of agonist action and little reassertion behaviour unless supramaximal concentrations are used), as exemplified by carmoterol. Results are discussed in the context of the two theories proposed to explain the long duration of action of salmeterol (binding to a specific 'exosite' of the ß(2)-adrenoceptor) and formoterol (membrane deposition: micro-kinetic theory). Our data suggest that the micro-kinetic theory is an adequate explanation to explain the long duration of action of the ß(2)-adrenoceptor agonists studied in these two assays, although with the current data set we cannot definitively exclude the 'exosite' theory.

Rel/NF-kappa B transcription factors and I kappa B inhibitors: evolution from a unique common ancestor.

From the sequences of Rel/NF-kappa B and I kappa B proteins, we constructed an alignment of their Rel Homology Domain (RHD) and ankyrin repeat domain. Using this alignment, we performed tree reconstruction with both distance matrix and parsimony analysis and estimated the branching robustness using bootstrap resampling methods. We defined four subfamilies of Rel/NF-kappa B transcription factors: (i) cRel, RelA, RelB, Dorsal and Dif; (ii) NF-kappa B1 and NF-kappa B2; (iii) Relish and (iv) NF-AT factors, the most divergent members. Subfamilies I and II are clustered together whereas Relish diverged earlier than other Rel/NF-kappa B proteins. Three subfamilies of I kappa B inhibitors were also defined: (i) NF-kappa B1 and NF-kappa B2; (ii) close to subfamily I, the short I kappa B proteins I kappa B alpha, I kappa B beta and Bcl-3; (iii) Relish that diverged earlier than other I kappa B inhibitors. Our definition of groups and subfamilies fits to structural and functional features of the Rel/NF-kappa B and I kappa B proteins. We also showed that ankyrin repeats of NF-kappa B1, NF-kappa B2 and Relish are short I kappa B-specific ankyrin motifs. These proteins defining a link between Rel/NF-kappa B and I kappa B families, we propose that all these factors evolved from a common ancestral RHD-ankyrin structure within a unique superfamily, explaining the specificities of interaction between the different Rel/NF-kappa B dimers and the various I kappa B inhibitors.

Isolation and characterization of a chicken homologue of the Spi-1/PU.1 transcription factor.

Spi-1/PU.1 is a member of the Ets family of transcription factors important in regulation of hematopoiesis. We have isolated a chicken cDNA homologuous to the mammalian Spi-1/PU.1 gene with an open reading frame of 250 amino acids (aa). The chicken Spi-1/PU.1 protein is 14 aa and 16 aa shorter than its human and mouse counterparts but is extremely well conserved with 78.8% and 75.2% identity respectively. The carboxy terminal DNA binding region, or ETS binding domain, is 100% identical to that of human and mouse. Some differences with the mammalian homologues are seen in the N-terminal part of the protein and in the PEST connecting domain. However, the differences are mainly conservative and all the features underlying functional aspects seem preserved. The major discrepancy lies in a 12 aa deletion in an already poorly conserved part of the PEST sequence. Spi-1/PU.1 transcripts were detected at high levels in spleen and Fabricius bursa of chick embryos by Northern blot and in situ hybridization. Our results show that the chicken Spi-1/PU.1 protein behaves like a bonafide Spi-1/PU.1 transcription factor in its DNA binding and transactivating properties.

Constitutive expression of the DNA-binding domain of Ets1 increases endothelial cell adhesion and stimulates their organization into capillary-like structures.

We previously reported that the Ets1 transcription factor is expressed in endothelial cells during angiogenesis both in normal and pathological development. We analyse here the effects of the stable expression of an Ets transdominant negative mutant (Ets1-DB), consisting in an Ets1 protein lacking its transactivation domain. A retrovirus containing the Ets1-DB sequence fused to an IRES-Neo sequence was designed and used to infect brain capillary (IBE) and aorta (MAE) mouse endothelial cell lines. Cells expressing this Ets1 mutant were examined for proliferation, migration and adhesion. Consistent changes were observed on cell morphology, with increased spreading and modifications in the organization of the cytoskeleton, and increased cell adhesion. We investigated the ability of endothelial cells to organise into capillary-like structures using three-dimensional gels. On Matrigel, all endothelial cell lines formed a cord-like network within 24 h, with an increased ability of Ets1-DB cells to spread on this substrate. In long term cultures, IBE cells expressing Ets1-DB showed a higher capacity to form branched structures; this effect was potentiated by FGF2. These results demonstrate a role of the Ets transcription factors in the regulation of the adhesive and morphogenetic properties of endothelial cells.

The avian transcription factor c-Rel is induced and translocates into the nucleus of thymocytes undergoing apoptosis.

This study investigates the involvement of the avian transcription factor c-Rel in thymocyte apoptosis occurring either in vivo or in organotypic culture. In vivo, only a few cortical thymocytes express the c-Rel protein. Their number, localization and morphology resemble that of apoptotic cells evidenced by TUNEL staining. In organotypic culture, the expression of c-Rel is induced in medullary thymocytes as apoptosis is triggered. This induction would be post-transcriptional since no increase in the c-rel gene expression is detected. Moreover, c-Rel translocates into the nucleus of medullary thymocytes during the time course of apoptosis. This translocation is preceded by a decrease in ikba expression, the gene which encodes the avian homologue of IkappaBalpha. Altogether these results suggest that the proto-oncogene c-rel could take an active part in apoptosis of cortical thymocytes occurring in vivo during T-cell selection as well as in experimentally-induced apoptosis of medullary thymocytes.

Budd-Chiari syndrome with thrombosis of the inferior vena cava: long-term patency of meso-caval and cavoatrial prosthetic bypass.

Portacaval or mesocaval shunts may relieve ascites that is caused by chronic forms of primary Budd-Chiari syndrome. When inferior vena cava stenosis is severe or is the site of thrombosis, another procedure has to be used. Portoatrial or cavoatrial shunting has been suggested, and a few reports have been made after only a short follow-up period. The case of a young woman with long-standing ascites caused by primary occlusion of the hepatic veins illustrates the incomplete relief of ascites after mesocaval shunt, which was caused by severe stenosis of the inferior vena cava. At 2 1/2-year follow-up, thrombosis of the retrohepatic inferior vena cava was documented and the mesocaval shunt remained patent. Cavoatrial bypass performed with the use of a long Dacron graft was successful as noted at a 4 1/2-year postoperative follow-up, and there was angiographic proof of patency. Budd-Chiari syndrome with stenosis or thrombosis of the inferior vena cava may be cured by prosthetic bypasses to the right atrium. Combined mesocaval and cavoatrial shunt should be encouraged in this specific situation.

Hemodynamic and biochemical monitoring during major liver resection with use of hepatic vascular exclusion.

Twenty-four resections under hepatic vascular exclusion (HVE) have been performed in patients with massive liver tumors. The procedure of HVE was used to minimize blood loss and the chance of gas embolism; it included clamping of the portal triad and occlusion of the inferior vena cava above and below the liver. In 12 of these patients the HVE was associated with clamping of the abdominal aorta above the celiac axis (AoC). During the "anhepatic" phase, which lasted 24 to 65 minutes (mean 39 minutes), neither venous shunt nor refrigeration was used. When HVE was associated with AoC, the circulation to the lower part of the body was completely excluded so that the systemic circulation was reduced to a small upper compartment in which the mean arterial pressure increased by 33% while the cardiac index decreased by 40%. The diastolic pulmonary arterial pressure remained unchanged. When HVE was not associated with AoC, the body was divided into an upper vascular compartment with normal venous resistance and a lower vascular compartment with increased resistance to the venous return and increased blood volume. The cardiac index, which was distributed to these two compartments, decreased by 40% to 50% but the mean arterial pressure decreased by only 14%. The good hemodynamic tolerance to HVE without AoC that was observed in these patients confirms the efficiency of collateral venous channels in the circumstances reported. AoC appears to be unnecessary in most patients if accurate fluid volume loading has been achieved before HVE. The study of acid-base balance demonstrates the ability of the human body to correct spontaneously the acidosis that follows the release of the clamps, provided a stable hemodynamic state is maintained. Only minor disorders of coagulation, without abnormal bleeding, were observed, and no prophylactic treatment was necessary. There were no deaths during operation, but a 25% postoperative mortality rate was observed mainly related to the underlying disease and the status of the remnant liver parenchyma. Despite its apparent sophistication, HVE is a simple and safe procedure for performing otherwise hazardous liver resections for tumors of large size or that are located close to the inferior vena cava and the suprahepatic veins. Its hemodynamic and metabolic consequences appear to be moderate.

Liver ischemia for hepatic resection: where is the limit?

BACKGROUND: A consecutive series of 50 patients who submitted to 53 hepatic resections with use of continuous normothermic liver ischemia is reported. METHODS: Portal triad clamping has been used in 28 cases, with associated inferior vena caval clamping above and below the liver (hepatic vascular exclusion) in 25 patients. The size of the tumor required major hepatic resection in 38 cases (71.7%). Malignant tumors (83%) were the most common indication for liver resection. Patients were placed in three groups according to the duration of liver ischemia: group A, less than 30 minutes (9 patients); group B, 30 to 60 minutes (29 patients); and group C, 60 or more (15 patients). RESULTS: No differences in mortality rates (5.7% in the entire series and 0% in group C) and morbidity rate could be shown. No significant difference was found in postoperative liver test results, and no persistent alteration remained thereafter. Liver biopsy at 6 and 12 months after operation did not reveal any chronic damage. Liver capability to regenerate was maintained as documented by postoperative computerized tomography scan or magnetic resonance imaging. CONCLUSIONS: Because interruption of hepatic blood flow in normothermia is safe for at least 60 minutes (up to 85 minutes in this study), vascular clamping is recommended for hazardous liver resections to minimize blood loss, which appears to be the main factor of death and morbidity.

Resection of the suprarenal inferior vena cava. The role of prosthetic replacement.

OBJECTIVE: To review the role of prosthetic replacement after resection of the suprarenal portion of the inferior vena cava (IVC). DESIGN: Retrospective review of a series of six patients with malignant infiltration of the suprarenal IVC undergoing operation in the last 11 years. SETTING: Multispecialty referral center. PATIENTS: One primary leiomyosarcoma and five involvements of the IVC by liver carcinoma (n = 2), adrenal carcinoma (n = 2), and recurrent renal carcinoma (n = 1). INTERVENTIONS: En bloc resection of the tumor with the IVC under total vascular exclusion of the liver in four cases, combined major liver resection in four cases, venous resection including the renal confluence in four cases, prosthetic venous replacement in four cases, and no venous replacement in two cases. MAIN OUTCOME MEASURES: Mortality, venous patency, clinical assessment, and malignant recurrence. RESULTS: One postoperative death (renal failure) following extended resection with right nephrectomy and ligature of the left renal vein. Graft patency was controlled in survivors, with good functional result. Among two patients without venous replacement, one with complete caval obstruction and marked collateral circulation has had a good result, and one with partial caval obstruction experienced transient symptoms of venous insufficiency. Malignant recurrence led to death in four patients (4, 6, 37, and 42 months after surgery). CONCLUSIONS: Suprarenal IVC reconstruction is justified in selected cases, with good functional results. When the renal confluence is resected along with the IVC, renal vein reconstruction may be needed to avoid acute renal failure. The oncologic results of such extensive resections are poor. Adjuvant therapy should be evaluated.

Tolerance of the human liver to prolonged normothermic ischemia. A biological study of 20 patients submitted to extensive hepatectomy.

To evaluate the biological tolerance of the human liver to prolonged warm ischemia, two groups of extensive hepatic resection for tumor were compared. Group 1 (11 patients) performed with short hepatic inflow occlusion (7 [mean] +/- 2 [SEM] minutes), and group 2 (nine patients) operated with use of complete hepatic vascular exclusion and prolonged warm liver ischemia (38 [mean] +/- 5 [SEM] minutes). Comparison of biological values, such as transaminase, bilirubin, total protein, albumin, and fibrinogen levels, the platelet count, prothrombin complex, and proaccelerin level, did not show statistically significant differences between the two groups. Therefore, the hepatic warm ischemia period may be, if needed, safely extended beyond the classical 15 minutes. It lasted 65 minutes in one case without adverse effect. These clinical observations parallel recent experimental work and should destroy the myth of the high sensitivity of the liver to warm ischemia.

Bacterial translocation during portal clamping for liver resection. A clinical study.

OBJECTIVE: To determine the incidence and the clinical importance of gut-bacterial translocation after portal triad clamping for liver resection. DESIGN: Cohort study. SETTING: Multispecialty referral center. PATIENTS: Five cirrhotic and 10 noncirrhotic patients requiring liver resection. INTERVENTIONS: Elective liver resection under normothermic ischemic conditions (mean +/- SD duration, 40.2 +/- 13.1 minutes). Simultaneous sampling for qualitative culture of the systemic and portal blood, the upper gastrointestinal tract fluid, and a mesenteric lymph node (MLN) before and after liver resection. MAIN OUTCOME MEASURES: Positive culture rate, type of organism isolated, and septic complications rate. RESULTS: Before resection, blood cultures and MLNs were sterile in all but 1 patient; this culture-positive patient had had a recent colon resection for occlusive carcinoma and was excluded from further analysis. After resection, systemic and portal blood cultures were sterile in all cases. Conversely, the MNLs were culture positive in 6 (43%) of 14 patients. Coagulase-negative staphylococci were the most common isolates. A weak correlation was observed between the organisms isolated from the MLNs and those simultaneously present in the upper gastrointestinal tract fluid. There was no relationship between bacterial translocation and the outcome as patients with culture-positive MLNs showed no evidence of intraperitoneal septic complications and the only patient with a septic complication (a subphrenic abscess) had negative cultures after resection. CONCLUSION: A significant bacterial translocation in the MLNs occurs after portal triad clamping and liver resection, although not clinically relevant.

Transjugular intrahepatic portosystemic shunt for Budd-Chiari syndrome after failure of surgical shunting.

A case of acute Budd-Chiari syndrome in a 26-year-old woman is reported. After a mesocaval shunt, the patient remained asymptomatic for 21 months, but ascites and hepatomegaly reappeared due to inferior vena cava stenosis subsequently treated by balloon dilation. Recurrence of stenosis indicated the need for a cavoatrial shunt with an expanded polytetrafluoroethylene prosthesis, which was followed by a complete recovery during the next 29 months. Radiological follow-up with magnetic resonance imaging demonstrated progressive hepatomegaly, thrombosis of the cavoatrial shunt, and stenosis of the mesocaval shunt. A transjugular intrahepatic portosystemic shunt was carried out, despite the absence of any patent residual hepatic vein at the usual level, by perforating the inferior vena cava and liver up to the right portal vein. An expandable 12-mm stent was successful in decreasing liver congestion. Dilation of the transjugular intrahepatic portosystemic shunt was done 15 months later, and the patient remains asymptomatic after a follow-up of 18 months.

Hepatic resection with ischemia of the liver exceeding one hour.

Twenty-six hepatic resections were performed using vascular clamping lasting more than one hour. The average duration of continuous normothermic ischemia was 67.0 +/- 7.5 minutes (plus or minus standard error of the mean) (range of 60 to 85 minutes). Vascular occlusion consisted of simple portal triad clamping in 14 patients and of hepatic vascular exclusion in 12. Extensive hepatectomy was performed upon more than 80 percent of the patients. One postoperative death was recorded. Extensive complications occurred in eight patients, including one case of hepatic failure. Postoperative changes in hepatic function tests were mild and transient. The rate of postoperative complications was higher in the group of patients with chronic hepatic disease (77.8 versus 11.8 percent, p < 0.005). Prolonged hepatic ischemia should not be considered a risk factor in patients with normal livers, whereas morbidity and mortality rates are seriously affected by the presence of chronic hepatic disease.

Extended left hepatectomy with vascular exclusion.

Extended left hepatectomy represents the most extensive and difficult type of hepatic resection. The risk of hemorrhage during transection of the hepatic parenchyma and subsequently the risk of biliary complications may be minimized with use of hepatic vascular exclusion.

The role of abdominal drainage after major hepatic resection.

The authors reviewed their recent experience with major hepatic resection in order to evaluate the role of abdominal drainage in the development and treatment of postoperative complications. Fifty-one patients underwent major hepatectomy with abdominal drainage; 44 of these patients (86%) for malignancy (average age at operation: 59 years). Drains were removed after a median period of 4 days. Major complications occurred in 16 patients (31%), and 3 patients (6%) had a fatal outcome. Twenty patients (39%) experienced minor complications, including 6 cases (12%) of ascitic leak from the insertion site. Considering the type and extent of liver resections reported in this series, these results suggest that abdominal drainage, if technically adequate and maintained for a short period, is not responsible for a high rate of postoperative complications. Its use, although questionable after limited resections, is, therefore, still recommended after difficult and extended hepatectomies.

Technique of hepatic vascular exclusion for extensive liver resection.

Hepatic vascular exclusion, which includes clamping of the portal pedicle along with the inferior vena cava below and above the liver, may be a useful procedure for resection of liver tumors close to the hepatic veins or the vena cava that are usually considered unresectable by conventional techniques. Since complete caval exclusion is the key to good hemodynamic tolerance and a bloodless transection of the liver parenchyma, several technical aspects of the procedure must be accomplished and are detailed.

Hepatic vascular exclusion (HVE) for major liver resections.

One hundred fifty-three patients underwent hepatic resection. Hepatic venous exclusion (HVE) was utilized in 23%. Aortic clamping was used in 20% of cases with hepatic venous exclusion. The mean duration of liver ischemia was 33 minutes. HVE increases the resectability of massive posterior or hypervascular liver tumors and prevents the risk of massive bleeding or air embolism. The only counterindication is the presence of severe preexisting cardiac dysfunction.

Surgical resection of liver metastases from colo-rectal cancers.

Surgical resection is currently the only potentially curative treatment in some selected patients with colo-rectal liver metastases (LM). Unfortunately only a minority of patients are candidates for resection. Only solitary or unilobar LM that can be removed by partial liver resection, are considered to be resectable. The second condition for the resection of LM is that the primary cancer must be resected. The third condition for resection is that the patient must be able to undergo a major liver resection if it is necessary. Small metastases which do not exceed 5 cm, and appear on the surface of the liver can be removed by a simple wedge resection. If the tumor is larger than 5 cm, or if multiple unilobar nodules are discovered, a major liver resection becomes necessary. Hospital mortality does not exceed 5% in most published series. Five year survivals are very rare when histologically proven colo-rectal LM are left in place. After surgical resection of LM, five year survival rates are close to 25% and range from 18% to 52%. Surgical resection is of benefit to approximately one fourth of the patients, who survive five years or more, but three fourths of the patients have early recurrences. None of the studied criteria can predict which patients will benefit from surgical resection of LM. In order to try to reduce the rate of early recurrences adjuvant chemotherapy has been proposed. No positive data have yet been obtained.

[Leiomyosarcoma of the inferior vena cava invading into the liver. Complete resection with venous reconstruction]. / Léiomyosarcome de la veine cave inférieure étendu au foie Résection complète avec reconstruction veineuse.

A case of leiomyosarcoma of the retrohepatic inferior vena cava associated with metastasis in the right liver lobe is reported. Resection included extended right hepatectomy, right nephrectomy, and tumor--containing inferior vena cava resection followed by polytetrafluoroethylene tube reconstruction. A comfortable survival was obtained before multifocal malignant spread led to death 42 months after surgery.

[Results of choledoco-duodenostomy for common bile duct lithiasis]. / Résultats de la cholédoco-duodénostomie pour lithiase de la voie biliaire principale.

One hundred and sixty-seven choledoco-duodenostomies for lithiasis of the common bile duct (CBD) were performed. The mean age of the patients was 74 +/- 1 years. Sixty p. 100 of the patients presented with at least one operative risk factor, usually related to their general condition. An anastomosis of at least 20 mm in diameter was possible as the diameter of the CBC was always larger than 10 mm. Immediate postoperative complications (within one month) were observed in 29 cases (17 p. 100). In 14 cases (8 p. 100), these complications were directly related to the operative procedure and, in 15 cases (9 p. 100), bronchopulmonary or cardiovascular complications occurred. Operative mortality was 4 p. 100 (7 cases); in 2 cases, death was directly related to the operative procedure, and in 5 cases, death was not directly due to surgery. Operative complications were significantly higher in the case of emergency procedures, impaction of the CBD by multiple stones, and associated acute cholecystitis. One hundred and thirty-four of the 160 survivors (84 p. 100) have been followed for a mean duration of 5 years (63 +/- 7 months); 115 (86 p. 100) have remained asymptomatic. Eleven patients had non specific findings; 8 (6 p. 100) had cholangitis, half of them having suffered from only one episode. The first (or only) episode occurred during the first postoperative year in 7 out of 8 patients. No cholangitis developed after the second postoperative year in patients still asymptomatic. No anastomotic stenosis was found in any of these cases. One case of stump syndrome was observed. These results suggest that choledocoduodenostomy is a reliable procedure for treatment of choledocolithiasis and related late complications are rare.