[Effect of portal branch ligation on liver regeneration in the rat]

GOAL

The aim of this study was to assess liver regeneration after partial portal ligation.

METHODS

70% partial portal occlusion was obtained by ligation of the left portal vein branch. Total liver weight ratio were measured 96 hours after partial portal occlusion and in sham operated animals. The kinetics of hepatocytes division was evaluated by measuring the incorporation of 5-bromo-21-deoxyuridine into replicating cells at various time points by immunohistochemistry.

RESULTS

Partial portal occlusion did not alter the total liver weight 96 hours after surgery. It resulted in atrophy of the ligated lobes and hypertrophy of the lobes with preserved portal flow. Hypertrophy was associated to an increase of the percentage of replicating hepatocytes. The replication rate was maximum at 28 hours with a peak at 12.5% and was prolonged beyond the 48th hour.

CONCLUSIONS

Partial portal occlusion results in major and prolonged regeneration process in the liver lobes with preserved portal flow.

Suppression of atrial myosin gene expression occurs independently in the left and right ventricles of the developing mouse heart

Many cardiac genes are broadly expressed in the early heart and become restricted to the atria or ventricles as development proceeds. Additional transcriptional differences between left and right compartments of the embryonic heart have been described recently, in particular for a number of transgenes containing cardiac regulatory elements. We now demonstrate that three myosin genes which become transcriptionally restricted to the atria between embryonic day (E) 12.5 and birth, alpha-myosin heavy chain (MHC), myosin light chain (MLC) 1A and MLC2A, are coordinately downregulated in the compact myocardium of the left ventricle before that of the right ventricle. alpha-MHC protein also accumulates in the right, but not left, compact ventricular myocardium during this period, suggesting that this transient regionalization contributes to fktal heart function. dHAND and eHAND, basic helix-loop-helix transcription factors known to be expressed in the right and left ventricles respectively at E10. 5, remain regionalized between E12.5 and E14.5. Downregulation of alpha-MHC, MLC1A, and MLC2A in iv/iv embryos, which have defective left/right patterning, initiates in the morphological left (systemic) ventricle regardless of its anatomical position on the right or left hand side of the heart. This points to the importance of left/right ventricular differences in sarcomeric gene expression patterns during fktal cardiogenesis and indicates that these differences originate in the embryo in response to anterior-posterior patterning of the heart tube rather than as a result of cardiac looping. Dev Dyn 2000;217:75-85.

Laparoscopic cystogastrostomy for pancreatic pseudocyst is safe and effective

Between March 1997 and March 1998, three consecutive patients underwent laparoscopic cystogastrostomy for persistent giant retrogastric pancreatic pseudocyst complicating an attack of acute pancreatitis. The mean cyst diameter was 15 +/- 1 cm (range 14-16). The procedure was performed with four trocars. The anterior wall of the stomach was opened longitudinally. The pseudocyst was entered through the posterior wall of the stomach. A cystogastrostomy was created by suturing the margins of the communication by interrupted nonabsorbable sutures. The mean operative time was 123 +/- 15 min, and there were no postoperative complications. The mean postoperative hospital stay was 4 +/- 1 days. Computed tomography demonstrated complete resolution of the pseudocyst. Laparoscopic cystogastrostomy represents a good therapeutic option for persistent retrogastric pancreatic pseudocyst.

RNA content differs in slow and fast muscle fibers: implications for interpretation of changes in muscle gene expression

Quantification of a specific muscle mRNA per total RNA (e.g., by Northern blot analysis) plays a crucial role in assessment of developmental, experimental, or pathological changes in gene expression. However, total RNA content per gram of a particular fiber type may differ as well. We have tested this possibility in the distinct fiber types of adult rat skeletal muscle. Sections of single fibers were hybridized against 28S rRNA as a marker for RNA content. Quantification of the hybridization showed that the 28S rRNA content decreases in the order I>IIA>IIX>IIB, where Type I fibers show a five- to sixfold higher expression level compared to Type IIB fibers. Results were verified with an independent biochemical determination of total RNA content performed on pools of histochemically defined freeze-dried single fibers. In addition, the proportion of myosin heavy chain (MHC) mRNA per microgram of total RNA was similar in slow and fast fibers, as demonstrated by Northern blot analysis. Consequently, Type I fibers contain five- to sixfold more MHC mRNA per microgram of tissue than IIB fibers. These differences are not reflected in the total fiber protein content. This study implies that proper assessment of mRNA levels in skeletal muscle requires evaluation of total RNA levels according to fiber type composition.

Beta-catenin mutations in hepatocellular carcinoma correlate with a low rate of loss of heterozygosity

To determine the frequency of Wnt/Wingless beta catenin pathway alteration in human hepatocellular carcinoma, a beta catenin and APC gene mutation screening was performed in a series of 119 tumors. An activating beta catenin mutation in exon 3 was found in 18% of the cases. Among tumors lacking beta catenin mutation, no APC mutation has been evidenced in a subset of 30 cases tested. The correlation between beta catenin mutation status and chromosome segment deletions was studied on a set of 48 hyperploid tumors. Chromosome 1p, 4q and 16p deletions were significantly associated with the absence of beta catenin mutation (P<0.05). Furthermore the Fractional Allelic Loss was significantly smaller in the beta catenin mutated tumors than in the non-mutated tumors (0.12 versus 022). Taken together, these results suggest, the existence of two carcinogenesis mechanisms. The first mechanism implies a beta catenin activating mutation associated with a low rate of loss of heterozygosity. The second mechanism, operating in a context of chromosomal instability, would involve tumor suppressor genes.

Elective laparoscopic sigmoid colectomy for diverticulitis. Results of a prospective study

BACKGROUND

We undertook a prospective evaluation of elective laparoscopic sigmoid colectomy for diverticulitis in order to assess the risks and benefits of this approach.

METHODS

Between November 1992 and November 1996, 54 consecutive patients were included in this study. Their mean age was 59 +/- 13 years (range, 36-81). The number of attacks of diverticulitis before colectomy ranged from one to four (mean, 2.2 +/- 0.7). The operative technique consisted of elective division of the inferior mesenteric vessels, left colonic flexure mobilization, and colorectal anastomosis using the cross-stapling technique.

RESULTS

Five procedures (9.2%) were converted. The primary cause for conversion was obesity. These patients had a simple postoperative course. There were no postoperative deaths. Three patients (6.1%) developed abdominal complications, and four patients (8.2%) had abdominal wall complications. Postoperative paralytic ileus lasted only 2.3 +/- 0.7 days (range, 1-6), allowing for a rapid reintroduction of regular diet. The mean postoperative hospital stay was 6.4 +/- 2.7 days (range, 4-15).

CONCLUSIONS

Elective laparoscopic colectomy for diverticulitis is feasible in most cases. In most cases, the operative risk is low and the postoperative course is uneventful. Elective sigmoid laparoscopic colectomy should be considered a good therapeutic option for symptomatic diverticulitis.

Treatment with temozolomide and poly(ADP-ribose) polymerase inhibitors induces early apoptosis and increases base excision repair gene transcripts in leukemic cells resistant to triazene compounds

Methylating triazenes have shown marked antileukemic effects, possibly through generation of a variety of DNA adducts. Cells tolerant to O6-methylguanine due to a defect in the mismatch repair system (MRS), might become sensitive to other methyl adducts, by inhibiting the N-methylpurine repair, which requires base excision repair (BER) and poly(ADP-ribose) polymerase (PADPRP). Therefore, MRS-deficient Jurkat leukemic cells resistant to methylating triazenes, have been treated with temozolomide (TZM) and PADPRP inhibitors. Expression of PADPRP or molecules involved in the BER system [3-methylpurine-DNA glycosylase (MPG) and X-ray repair cross-complementing 1 (XRCC1)], have been explored. Cytotoxic effects of TZM associated with PADPRP inhibitors are evident shortly after treatment, suggesting that completion of cell division is not required for the lethal effect of the drug combination. Increase of PADPRP or MPG transcripts was found after treatment with TZM alone or combined with PADPRP inhibitor. XRCC1 transcript was positively modulated only in the case of drug combination. This could suggest that in the presence of PADPRP inhibitor, persistence of DNA damage triggers XRCC1 transcription. Our results suggest that association of TZM and PADPRP inhibitors might be of benefit for MRS-deficient malignancies unresponsive to the methylating agent.

Haemodynamic changes associated with portal triad clamping are suppressed by prior hepatic pedicle infiltration with lidocaine in humans

Portal triad clamping (PTC) reduces venous return of blood to the heart. However, the decrease in cardiac index (CI) is associated with an unexpected increase in mean arterial pressure (MAP) and the 40% increase in systemic vascular resistance is greater than anticipated in compensation for the 10% decrease in CI. We hypothesized that a reflex elicited in the peritoneum accounted for this unanticipated haemodynamic response. Twenty patients undergoing liver resection were allocated randomly to have hepatic pedicle infiltration before PTC with either lidocaine 200 mg or placebo. MAP was recorded, and plasma osmolality and plasma concentrations of vasopressin, epinephrine, norepinephrine, dopamine, renin and endothelin were measured. After PTC, MAP increased significantly in the placebo group but decreased significantly in the lidocaine group. Plasma concentrations of vasopressin, epinephrine and norepinephrine increased significantly in the placebo group. Plasma concentrations of vasopressin decreased significantly in the lidocaine group, while plasma concentrations of epinephrine and norepinephrine were unchanged. A subsequent study in eight patients found that neither haemodynamic nor hormonal changes associated with PTC in the placebo group were altered by administration of lidocaine 200 mg i.m. before PTC.

Permissiveness of human biliary epithelial cells to infection by hepatitis C virus

The cellular tropism of hepatitis C virus (HCV) is an important but much debated issue. Permissivity to HCV of biliary cells has never been demonstrated. In this context, we used gallbladder epithelial cells (GBEC) as a model of the more proximal biliary epithelium. These cells were isolated from HCV-positive and -negative individuals and cultured for up to 40 days. Biliary cells from HCV-negative subjects were infected in vitro with various inocula. The retention of GBEC functional characteristics was assessed by the expression of cystic fibrosis transmembrane conductance regulator (CFTR). All 12 GBEC tested from HCV-negative patients were successfully infected by HCV. This was assessed by: 1) the detection of HCV-RNA positive and negative strands; 2) the detection of the viral capsid by immunofluorescence; and 3) the combination of single-strand conformation polymorphism (SSCP) and HVR1 sequence analysis demonstrating the distinct majoritary HCV genomes in serum and in GBEC. The level of HCV RNA in cell extracts and supernatants was low, but HCV infection was highly reproducible. Our results expand those showing the cellular tropism of HCV, and demonstrate the sensitivity of biliary cells to HCV infection. This might have an important impact in terms of pathogenesis and pathological features of HCV infection. In addition, given the easy access to these cells and the high reproducibility of in vitro infection, they should constitute an important tool for studies aimed at analyzing the issue of HCV penetration and neutralizing antibodies.

[Laparoscopic cholecystectomy in acute cholecystitis]

PURPOSE

To determine the feasibility, operative risk and patients' benefit of laparoscopy in emergency cholecystectomy for acute calculous cholecystitis.

PATIENTS AND METHODS

From January 1991 to December 1998, 234 patients with acute calculous cholecystitis were operated on by emergency laparoscopic cholecystectomy. There were 131 women and 103 men (mean age: 57 years), (Asa 2: 48%, Asa 3: 10%). In seven patients, choledocolithiasis was detected by endoscopic ultrasonography and preoperatively treated by endoscopic sphincterotomy. The mean delay between in-hospital admission and cholecystectomy was 20 hours (2-160). Cholecystectomy was performed with primary approach of Calot's triangle. Intraoperative cholangiography, selectively performed (n = 70), detected choledocolithiasis in three patients.

RESULTS

The mean duration of surgery was 149 minutes (62-313). The conversion rate was 13% and decreased through the years. The postoperative complication rate was 18%. Eight patients (3.4%) had an abdominal complication. One patient (0.4%) died of bile peritonitis after intraoperative undetected main bile duct injury. The mean postoperative hospital stay was 6.04 days. It was 3.5 days only, very old patients and those with severe associated disease being excluded.

CONCLUSION

Laparoscopy appears to be a good approach for emergency cholecystectomy in patients with acute calculous cholecystitis.

Liver resection and needle liver biopsy cause hematogenous dissemination of liver cells

We have investigated whether liver resection and needle liver biopsy cause dissemination of liver cells into peripheral blood circulation, using a reverse-transcription polymerase chain reaction (RT-PCR)-based assay targeted against alpha-fetoprotein (AFP) mRNA. Twelve patients with and 16 without primary liver cancer (PLC) undergoing liver resection were tested before skin incision, after liver mobilization, after hepatic parenchyma transection, after abdominal wall suture, and 4 days after surgery. Two patients with and 20 without PLC were tested before, 20 minutes after, and 24 hours after needle liver biopsy. Six of 14 patients with and 0 of 36 patients without PLC scored positive before intervention (P <.001). Liver cell spreading was induced at different times after surgery and liver biopsy in 14 of 14 patients with but also 23 of 36 without PLC (P <.05). We conclude that liver resection and needle liver biopsy induce release of cells from the liver, which are not necessarily liver tumor cells, into the peripheral blood circulation. This may be, however, an important mechanism of liver cancer cell dissemination deserving further investigations.

Neoomphaloplasty: An old and new technique

The authors review several proposed approaches to neoomphaloplasty, with emphasis on the use of three flaps anchored to the fascia, allowing the exposed central area to heal unaided. The procedure is straightforward and can be performed singly or during abdominoplasty. Results are both cosmetic and natural-looking.

Expression of mutated hepatitis B virus X genes in human hepatocellular carcinomas

To explore the role of hepatitis B virus (HBV) X protein in liver carcinogenesis, independently from its role in viral replication, we have analyzed X gene structure and expression in tumorous and non-tumorous tissues obtained from 9 hepatitis B surface antigen (HBsAg)-negative, HBV DNA-positive patients. HBV replication was undetectable in tumorous tissues. HBV X gene was truncated at its 3' end in 5 of 9 tumorous tissues and 1 of 8 non-tumorous livers. Sequence analysis performed on uninterrupted X genes from 3 tumors and 3 surrounding non-tumorous tissues showed a high rate of mutations, selectively in the tumorous livers. In 1 of the 3 tumors, a frameshift mutation induced a new stop at codon 129. HBV RNAs were tested by reverse transcriptase-polymerase chain reaction (RT-PCR) with surface (S), core (C) and X specific primers. X, but not S and C, RNA expression was found in 6 of 8 tumors and in 6 of 7 non-tumorous tissues. This finding was consistent with immunohistochemical detection of X, but not S and C, antigens in all tumors also expressing X RNA. Our results provide evidence for selective expression of HBV X, but not S and C, RNA and protein in the tumorous and non-tumorous tissue of HBsAg-negative, HBV DNA-positive patients. It also shows that the structure of the X gene is modified (interrupted or highly mutated) in the majority of tumorous livers. Taken together, our findings are consistent with a potential role of mutated X proteins in HBV-related liver oncogenesis.

Expression of mutated hepatitis B virus X genes in human hepatocellular carcinomas

To explore the role of hepatitis B virus (HBV) X protein in liver carcinogenesis, independently from its role in viral replication, we have analyzed X gene structure and expression in tumorous and non-tumorous tissues obtained from 9 hepatitis B surface antigen (HBsAg)-negative, HBV DNA-positive patients. HBV replication was undetectable in tumorous tissues. HBV X gene was truncated at its 3' end in 5 of 9 tumorous tissues and 1 of 8 non-tumorous livers. Sequence analysis performed on uninterrupted X genes from 3 tumors and 3 surrounding non-tumorous tissues showed a high rate of mutations, selectively in the tumorous livers. In 1 of the 3 tumors, a frameshift mutation induced a new stop at codon 129. HBV RNAs were tested by reverse transcriptase-polymerase chain reaction (RT-PCR) with surface (S), core (C) and X specific primers. X, but not S and C, RNA expression was found in 6 of 8 tumors and in 6 of 7 non-tumorous tissues. This finding was consistent with immunohistochemical detection of X, but not S and C, antigens in all tumors also expressing X RNA. Our results provide evidence for selective expression of HBV X, but not S and C, RNA and protein in the tumorous and non-tumorous tissue of HBsAg-negative, HBV DNA-positive patients. It also shows that the structure of the X gene is modified (interrupted or highly mutated) in the majority of tumorous livers. Taken together, our findings are consistent with a potential role of mutated X proteins in HBV-related liver oncogenesis.

Expression of mutated hepatitis B virus X genes in human hepatocellular carcinomas

To explore the role of hepatitis B virus (HBV) X protein in liver carcinogenesis, independently from its role in viral replication, we have analyzed X gene structure and expression in tumorous and non-tumorous tissues obtained from 9 hepatitis B surface antigen (HBsAg)-negative, HBV DNA-positive patients. HBV replication was undetectable in tumorous tissues. HBV X gene was truncated at its 3' end in 5 of 9 tumorous tissues and 1 of 8 non-tumorous livers. Sequence analysis performed on uninterrupted X genes from 3 tumors and 3 surrounding non-tumorous tissues showed a high rate of mutations, selectively in the tumorous livers. In 1 of the 3 tumors, a frameshift mutation induced a new stop at codon 129. HBV RNAs were tested by reverse transcriptase-polymerase chain reaction (RT-PCR) with surface (S), core (C) and X specific primers. X, but not S and C, RNA expression was found in 6 of 8 tumors and in 6 of 7 non-tumorous tissues. This finding was consistent with immunohistochemical detection of X, but not S and C, antigens in all tumors also expressing X RNA. Our results provide evidence for selective expression of HBV X, but not S and C, RNA and protein in the tumorous and non-tumorous tissue of HBsAg-negative, HBV DNA-positive patients. It also shows that the structure of the X gene is modified (interrupted or highly mutated) in the majority of tumorous livers. Taken together, our findings are consistent with a potential role of mutated X proteins in HBV-related liver oncogenesis.

Myosin light chain 2a and 2v identifies the embryonic outflow tract myocardium in the developing rodent heart

The embryonic heart consists of five segments comprising the fast-conducting atrial and ventricular segments flanked by slow-conducting segments, i.e. inflow tract, atrioventricular canal and outflow tract. Although the incorporation of the flanking segments into the definitive atrial and ventricular chambers with development is generally accepted now, the contribution of the outflow tract myocardium to the definitive ventricles remained controversial mainly due to the lack of appropriate markers. For that reason we performed a detailed study of the pattern of expression of myosin light chain (MLC) 2a and 2v by in situ hybridization and immunohistochemistry during rat and mouse heart development. Expression of MLC2a mRNA displays a postero-anterior gradient in the tubular heart. In the embryonic heart it is down-regulated in the ventricular compartment and remains high in the outflow tract, atrioventricular canal, atria and inflow tract myocardium. MLC2v is strongly expressed in the ventricular myocardium and distinctly lower in the outflow tract and atrioventricular canal. The co-expression of MLC2a and MLC2v in the outflow tract and atrioventricular canal, together with the single expression in the atrial (MLC2a) and ventricular (MLC2v) myocardium, permits the delineation of their boundaries. With development, myocardial cells are observed in the lower endocardial ridges that share MLC2a and MLC2v expression with the myocardial cells of the outflow tract. In neonates, MLC2a continues to be expressed around both right and left semilunar valves, the outlet septum and the non-trabeculated right ventricular outlet. These findings demonstrate the contribution of the outflow tract to the definitive ventricles and demonstrate that the outlet septum is derived from outflow tract myocardium.

In utero allotransplantation of retrovirally transduced fetal hepatocytes in primates: feasibility and short-term follow-up

In utero allotransplantation of fetal hepatocytes into a preimmune fetus could be used in early treatment of many inherited hepatic metabolic diseases. This study was designed to assess the tolerance to hepatocyte transplantation and to test the feasability and toxicity of such an injection in a primate model. Fetal hepatocytes were obtained from two 120-day-old Macaca mulatta fetuses and cryopreserved. They were thawed, cultured in vitro, and transduced with a recombinant retrovirus expressing beta-galactosidase. Transduction efficiency was 75-85%. Three unrelated fetuses (90, 100, and 104 days old) were each given 1-2 x 10(7) transduced cells via the umbilical vein. This caused vasospasm and severe bradycardia. Two fetuses died in the 48 hours after transplantation; the third survived and was killed at the end of gestation. No evidence of the infused cells was found. Three fetuses (90 days old) were, therefore, given 3-4 10(7) hepatocytes by direct intrahepatic injection. All the fetuses survived without side effect. Donor cells were not apparent from histochemical staining and PCR reactions. There was no evidence of inflammatory reaction. These findings indicate that the protocole could be improved by increasing the number of transplanted cells and using specific hepatic promoters in the retroviral vectors to achieve an effective postnatal chimerism.

[Treatment of hepatic recurrence after resection of hepatocellular carcinomas]

Between October 1990 and December 1995, 86 patients underwent hepatic resection for hepatocellular carcinoma (HCC). All resections were carried out with the aim of achieving complete cure. Fifty one (60%) of these patients subsequently developed recurrent HCC. Only twenty patients could be treated in our hospital. There were 18 men and 2 women, with a mean age of 61 years at the time of recurrence. Six patients had a normal liver. Fourteen patients had associated liver cirrhosis. using Pugh's classification, 7 patients were Pugh A, 6 Pugh B and 1 Pugh C. The initial hepatic resection had consisted of major hepatectomy in 9 cases and segmentectomy in the remaining 11 patients. The mean time to recurrence was 17 months. There were 3 recurrences on the resection margin and 17 recurrences away from the hepatic stump. The therapeutic choice after hepatic recurrence was based on the number of tumors, hepatic function and the size of the liver remnant. Six patients were treated by tamoxifen due to poor hepatic function; median survival after recurrence was 6 months. Four patients with a single recurrent tumor on an atrophied liver remnant were treated by percutaneous ethanol injection with a median survival after recurrence of 15 months. Five patients with multiple diffuse lesions and good hepatic function were treated by transarterial chemoembolisation with a median survival after recurrence of 30 months. Five patients with a solitary tumor and good hepatic function underwent a second hepatic resection with a median survival after recurrence of 35 months. The overall median survival after diagnosis of recurrence was 20 months. These results suggest that an active treatment should be carried out in cases of recurrence of HCC. A second resection, if technically possible, offers the best chance of survival.

[Results of laparoscopic treatment of abdominal emergencies]

The purpose of this retrospective study was to evaluate the results of the laparoscopic surgical treatment of abdominal emergencies. From May 1991 to September 1995, 200 patients operated by laparoscopy for an acute abdomen were included in this study. The decision to treat the patient by laparoscopy was taken by the surgeon on duty. There were 101 males and 99 females with a mean age of 41 +/- 20 years (range 11-90 years). The main indications for operation were: acute appendicitis (109 patients), acute cholecystitis (52 patients), small bowel obstruction (14 patients) and perforated duodenal ulcer (14 patients). There was no hospital mortality. One per cent of patients experienced an operative complication which was treated by laparotomy. Conversion to laparotomy was needed in 13% of cases. The morbidity rate was 9% and reoperation by laparotomy for acute generalized peritonitis secondary to small bowel perforation was necessary in two cases. Mean postoperative hospital stay ranged from 4 to 7 days. The authors conclude that surgical laparoscopic treatment of the common abdominal emergencies is safe. The conversion rate is low as is the complication rate. These conclusions should be confirmed by a prospective study.

Jaundice following laparoscopic cholecystectomy. An unusual complication of spilled stones

We report the first case of obstructive cholangitis after laparoscopic cholecystectomy, related to intraperitoneal retained gallstones.

Role of wild-type p53 on the antineoplastic activity of temozolomide alone or combined with inhibitors of poly(ADP-ribose) polymerase

The DNA repair enzyme O6-alkylguanine DNA-alkyltransferase (OGAT) and a deficient mismatch repair system play a critical role in the resistance to chemotherapeutic agents that generate adducts at the O6-position of guanine. However, DNA adducts different from O6-methylguanine might be also involved in cytotoxicity induced by methylating agents. Because the loss of p53 function is generally associated with tumor cell resistance to anticancer chemotherapy, we have investigated whether wild-type p53 might affect chemosensitivity of leukemia cells endowed with high OGAT levels to the methylating agent temozolomide (TZM). The effect of poly(ADP-ribose) polymerase (PADPRP) inhibition, which potentiates the cytotoxic effects of N7-methylguanine and N3-methylguanine, was also assessed in OGAT-proficient cells, either susceptible or tolerant to O6-methylguanine. OGAT-proficient and p53 null HL60 cells were transfected with the human p53 cDNA (p53+ cells). Treatment with TZM concentrations not toxic for the cells transduced with the control vector (p53-cells), induced apoptosis in p53+ cells. These cells were characterized by a lower level of bcl-2 protein than p53- cells, whereas bax and OGAT expression was comparable in both lines. Inhibition of PADPRP potentiated the cytotoxic and apoptotic effects of TZM in either p53- or p53+ HL60 cells. Furthermore, PADPRP inhibitors potentiated apoptosis induced by TZM in Jurkat cells, which possess a mutated p53 gene and are tolerant to O6-methylguanine adducts. The analysis of cell cycle indicated that the drug combination of TZM and PADPRP inhibitors provoked G1 arrest only in p53+ cells. Conversely, G1 arrest was not observed in p53+ cells exposed to TZM alone. It is possible to speculate that PADPRP inhibitors might affect the repair of DNA adducts that are processed differently from O6 methylguanine and induce a different pattern of cell cycle distribution. In conclusion, the results show that p53 increases apoptosis by TZM in OGAT-proficient cells and suggest the potential role of PADPRP inhibitors in enhancing TZM activity against leukemias independently of DNA repair systems.

Normal development of the outflow tract in the rat

The outflow tract (OFT) provides the structural components forming the ventriculoarterial connection. The prevailing concept that this junction "rotates" to acquire its definitive topography also requires a concept of "counterrotation" and is difficult to reconcile with cell-marking studies. Rats between 10 embryonic days (EDs) and 2 postnatal days were stained immunohistochemically and by in situ hybridization. DNA replication was determined by incorporation of bromodeoxyuridine and apoptosis by the annexin V binding and terminal deoxynucleotidyl transferase-mediated dUTP-X nick end labeling (TUNEL) assays. Starting at ED12, cardiomyocytes in the distal (truncal) part of the OFT begin to shed their myocardial phenotype without proceeding into apoptosis, suggesting transdifferentiation. Myocardial regression is most pronounced on the dextroposterior side and continues until after birth, as revealed by the disappearance of the myocardial cuff surrounding the coronary roots and semilunar sinuses and by the establishment of fibrous continuity between mitral and aortic semilunar valves. Fusion of the endocardial ridges of the truncus on late ED13 is accompanied by the organization of alpha-smooth muscle actin-and nonmuscle myosin heavy chain-positive myofibroblasts into a central whorl and the appearance of the semilunar valve anlagen at their definitive topographical position within the proximal portion of the truncus. After fusion of the proximal (conal) portion of the endocardial ridges, many of the resident myofibroblasts undergo apoptosis and are replaced by cardiomyocytes. The distal myocardial boundary of the OFT is not a stable landmark but moves proximally over the spiraling course of the aortic and pulmonary routes, so that the semilunar valves develop at their definitive topographic position. After septation, the distal boundary of the OFT continues to regress, particularly in its subaortic portion. The myocardializing conus septum, on the other hand, becomes largely incorporated into the right ventricle. These opposite developments account for the pronounced asymmetry of the subaortic and subpulmonary outlets in the formed heart.

[Characterization of liver regeneration in the albumin-urokinase transgenic mouse]

Models of liver regeneration are essential to understand mechanisms of hepatic carcinogenesis, correct genetic diseases by gene transfer or hepatocyte transplantation. The expression in the liver of transgenic mice of a gene coding for a urokinase-type plasminogen activator (uPA mouse) induces hepatotoxicity and prolonged post-native liver regeneration from cellular clones which have inactivated the transgene. This model may have major applications but it remains necessary to characterize the liver regeneration pattern.

METHODS

Histological and immunohistochemical studies of the liver of uPA and non-transgenic mice, 3, 7, 14, 21, 28, 42 and 56 days-old. Markers of cellular proliferation: 5-bromo-2'deoxyuridine (BrdU) and proliferating cell nuclear antigen (PCNA).

RESULTS

Regenerative nodules were seen from day 14. These nodules then grew, became confluent and by 8 weeks constituted the entire liver mass. A semi-quantitative study of BrdU and PCNA showed a maximal labeling at day 7 (300 to 350 labeled cells/10 microscopic fields, mag 400). When the nodules appeared, 60 to 80% of the cells were labeled. The proportion of labeled cells decreased but was still greater than that observed in non transgenic mice up to day 56 (92 to 106 labeled cells vs 10 to 28, on day 28).

CONCLUSIONS

In uPA mouse liver regeneration is significantly expanded, as compared to the regeneration following partial hepatectom. This study therefore has allowed to determine the best conditions for using this model.

[Liver resection in patients with polycystic liver disease]

OBJECTIVES

Polycystic liver disease is sometimes responsible for chronic symptoms linked to hepatomegaly which can result in acute complications such hemorrhage or infection of cysts. The aim of this retrospective study was to evaluate the results of partial hepatic resection in patients with symptomatic or complicated polycystic liver disease.

METHODS

Twelve patients (11 women and one man, mean age 49) with diffuse polycystic liver disease were treated by partial liver resection (left lateral lobectomy in 7, left hepatectomy in 4, and extended right hepatectomy in 1). Four patients had terminal renal failures and three had chronic haemodialysis. Median follow-up was 34 months.

RESULTS

Ascites occurred postoperatively in 10 patients (83%) and was long-lasting (> 2 weeks) in 5; all patients with end-stage renal failure had long-lasting ascites. One of them died on the 40th postoperative day of ascites infection. Another patient with end-stage renal failure died two years postoperatively from chronic disabling ascites and malnutrition while awaiting kidney transplantation. The 10 other patients were markedly improved after partial liver resection, including a marked decrease in hepatomegaly, and the disappearance of chronic symptoms and cystic complications. This beneficial effect was incomplete in the two surviving patients with end-stage renal failure until kidney transplantation was performed.

CONCLUSION

These results suggest that partial liver resection is a highly effective treatment in patients with symptomatic polycystic liver disease, preferably before the onset of end-stage renal failure.

Chromosomal aberrations in hepatocellular carcinomas: relationship with pathological features

Fluorescence in situ hybridization performed on tissue sections can reveal chromosomal abnormalities related to histopathological features. This technique was performed on serial frozen sections from seven normal livers and 29 hepatocellular carcinomas (HCCs) using pericentromeric repeat-specific probes for chromosomes 1, 4, 6, 7, 8, 16, and 17. For each HCC and each probe, the percentage of cells showing one, two, or more than two signals was counted and compared with the distribution in the normal liver. According to these results, HCCs were categorized as monosomic, disomic, or polysomic (more than two signals) for the chromosome tested. These data were compared with the main histopathological characteristics of HCC. Chromosome gains were very common, preferentially affecting chromosome 1 (23 of 27 cases, 85%), chromosome 16 (16 of 27 cases, 59%), chromosome 7 (16 of 29 cases, 55%), chromosome 6 (15 of 29 cases, 52%) and chromosome 8 (14 of 29 cases, 48%). Monosomy was seen more rarely, affecting preferentially chromosome 16 (19%), chromosome 17 (14%), and chromosome 4 (10%). A significant correlation was observed between aneusomy of chromosome 4 and tumor size (P < .05) or the presence of vascular embolism (P < .05). In conclusion, chromosomal gains are frequent genetic events in human HCC. A significant association between a gain in chromosome 4 and large tumor size or vascular embolism suggests that this genetic abnormality is a late event in liver carcinogenesis.

Turcot syndrome: case report and nosological aspects

The Turcot syndrome has been defined as the simultaneous presence of multiple polyposis of the colon and a malignant brain tumor. This association is supposed to be genetically transmitted, even though we still do not exactly know whether this occurs in a dominant or recessive way. The case of a 47-year-old man submitted to a right hemicolectomy for cancer and polyposis, following a series of endoscopic polypectomies and, finally, removal of left temporal glioma is here presented.

Spontaneous and iatrogenic spreading of liver-derived cells into peripheral blood of patients with primary liver cancer

The prognosis for patients with primary liver cancer (PLC) often depends on tumor recurrence and the development of extrahepatic metastases, particularly after liver transplantation. We have developed a sensitive test to detect both spontaneous circulation of tumor cells and the spread of liver cells due to chemoembolization and alcoholization. Reverse-transcription polymerase chain reaction was used to search for cells expressing alpha-fetoprotein (AFP) messenger RNA in the peripheral blood of 84 patients with PLC and 102 controls (55 patients with chronic hepatitis and/or cirrhosis, 10 patients with benign liver tumors or liver metastases from intestinal cancers, and 37 healthy individuals). By spiking the blood of healthy volunteers with HepG2 cells, we assessed the sensitivity limit: one HepG2 cell mixed with 10(7) leukocytes. All 102 controls tested negative. In contrast, 28 patients (33.3%) with PLC tested positive. Positivity for the test was significantly associated with portal thrombosis, tumor size, intravascular tumor emboli, serum AFP level, and extrahepatic metastases. Patients were followed up for a mean period of 39 +/- 51 weeks: the probability of developing extrahepatic metastases was significantly higher in positive than in negative patients. Eighteen negative patients with PLC were tested before, 1 hour after, and 24 hours after locoregional therapy: 9 tested positive either 1 or 24 hours after alcoholization or chemoembolization. In conclusion, we have developed a highly specific and sensitive test to detect circulating tumor cells in patients with PLC. This test is likely to be clinically useful in evaluating the risk of developing extrahepatic metastases and the possibility of iatrogenic spreading of liver-derived, possibly tumorous, cells.

Regionalized transcriptional domains of myosin light chain 3f transgenes in the embryonic mouse heart: morphogenetic implications

Within the embryonic heart, five segments can be distinguished: two fast-conducting atrial and ventricular compartments flanked by slow-conducting segments, the inflow tract, the atrioventricular canal, and the outflow tract. These compartments assume morphological identity as a result of looping of the linear heart tube. Subsequently, the formation of interatrial, interventricular, and outflow tract septa generates a four-chambered heart. The lack of markers that distinguish right and left compartments within the heart has prevented a precise understanding of these processes. Transgenic mice carrying an nlacZ reporter gene under transcriptional control of regulatory sequences from the MLC1F/3F gene provide specific markers to investigate such regionalization. Our results show that transgene expression is restricted to distinct regions of the myocardium: beta-galactosidase activity in 3F-nlacZ-2E mice is confined predominantly to the embryonic right atrium, atrioventricular canal, and left ventricle, whereas, in 3F-nlacZ-9 mice, the transgene is expressed in both atrial and ventricular segments (right/left) and in the atrioventricular canal, but not in the inflow and outflow tracts. These lines of mice illustrate that distinct embryonic cardiac regions have different transcriptional specificities and provide early markers of myocardial subdivisions. Regional differences in transgene expression are not detected in the linear heart tube but become apparent as the heart begins to loop. Subsequent regionalization of transgene expression provides new insights into later morphogenetic events, including the development of the atrioventricular canal and the fate of the outflow tract.

Expression of the cholinergic signal-transduction pathway components during embryonic rat heart development

BACKGROUND

Previous studies showed that acetylcholinesterase (AChE) activity is present in the downstream (arterial) part of the embryonic chick and rat heart, but its functional significance was unclear. To establish whether other components of a cholinergic signal-transduction pathway are present in the embryonic heart, we localised the mRNAs encoding choline acetyltransferase (ChAT), acetylcholinesterase (AChE), and the muscarinic receptor isoforms (mAChRs; m1-m5).

METHODS

Messenger RNA detection and localisation by in situ hybridisation and reverse transcriptase-polymerase chain reaction were employed.

RESULTS

Expression of ChAT and AChE mRNAs was observed from 15 embryonic days onward in the neural tissue covering the dorsocranial wall of the atria. Muscarinic receptors (m1, m2, m4) were observed at the same localisation as AChE and ChAT mRNAs, both during embryogenesis and after birth. In addition, m1 and m4 mAChRs showed a low level of expression in the atrial myocardium during the fetal period. No expression of the m3 or the m5 mAChRs was observed in or near the embryonic hearts. ChAT, AChE, and mAChRs (m1, m2, m4) mRNAs always colocalised in the cardiac ganglia. However, none of these mRNAs was found at a detectable level in the outflow tract and/or the ventricular trabeculations.

CONCLUSIONS

The AChE activity in the arterial part of the embryonic heart is probably synthesised elsewhere and subserves a function different from the hydrolysis of locally produced acetylcholine.

Aprotinin reduces blood loss in patients undergoing elective liver resection

Ninety-seven patients undergoing elective liver resection through a subcostal incision were assigned to large-dose aprotinin treatment or placebo in a double-blind, prospective, randomized fashion. Randomization was stratified by diagnosis: (a) cancer in cirrhosis, (b) cancer in healthy liver, and (c) benign tumor in healthy liver. Intraoperative blood loss, percentage of transfused patients, and total transfusion requirement per group were significantly lower in the aprotinin group than in the placebo group (1217 +/- 966 mL vs 1653 +/- 1221 mL, P = 0.048; 17% vs 39%, P = 0.02; 30 vs 77 red blood cell packs, P = 0.015, respectively). Assessment of hematological markers (a) prior to surgery, (b) at the end of surgery, and (c) 24 h after surgery showed an identical intraoperative increase in thrombin-antithrombin III complexes in patients of both groups (P = 0.86), which indicates a similar activation of coagulation. Intraoperative hyperfibrinolysis was significantly less pronounced in the aprotinin group than in the placebo group (P = 0.0002 and P = 0.004 for D-dimers and fibrinogen, respectively). No adverse drug effects were detected (circulatory disturbances, deep venous thrombosis, increase in serum creatinine). These results suggest that aprotinin significantly reduces blood loss and transfusion requirement in patients undergoing elective liver resection through a subcostal incision.

Preoperative predictors of blood transfusion in liver resection for tumor

BACKGROUND

Hepatic resection remains a hemorrhagic procedure. The purpose of this study was to investigate the preoperative predictive factors of intraoperative blood transfusion.

METHODS

One hundred consecutive patients who underwent hepatic resection for tumor were included in this retrospective study. Resection was performed for primary malignancies (n = 52), metastases (n = 18), and benign tumors (n = 30). Liver resection was performed under intermittent clamping of the portal triad. Seventeen variables were analyzed.

RESULTS

The operative blood loss was 1,872 mL (mean 1,104; range 650 to 4500) for the 22 transfused patients. The mean blood transfusion was 5.5 units (mean 3.2; range 2 to 12) of packed red cells. Multivariate analysis demonstrated that the size of liver resection (P <0.001) and the prothrombin rate (P <0.001) were independently correlated with blood transfusion.

CONCLUSIONS

Patients undergoing extended resection or with abnormal coagulation could be considered for autologous blood transfusion.

Is hepatectomy necessary in dealing with left hepatolithiasis with intrahepatic duct stricture?

Background: Hepatolithiasis with intrahepatic biliary strictures, more common in Southeast Asia than elsewhere, remains a difficult problem to manage. Hepatic resection has recently been advocated as one of the treatment modalities for hepatolithiasis; however, this procedure is not without risk. This study was designed to achieve complete clearance of the stones, eliminate bile stasis, and avoid the potential risks of hepatic resection in the patient with hepatolithiasis and intrahepatic biliary stricture.

Methods: In this prospective clinical trial 13 patients with retained left hepatolithiasis and intrahepatic biliary strictures were included. All the patients met the following criteria: (1) initial surgical procedure for hepatolithiasis, (2) normal gross findings of the left liver, and (3) no obvious clinical evidence of an associated intrahepatic cholangiocarcinoma. After the operation they underwent matured T-tube tract ductal dilatation with percutaneous transhepatic cholangioscopy tube stenting. Choledoschoscopic electrohydraulic lithotripsy was used in five patients after dilatation when impacted or large stones were encountered.

Results: Complete clearance of the stones was achieved in these 13 patients. One patient had fevers develop after ductal dilatation, and another patient had mild hemobilia after electrohydraulic lithotripsy. Both recovered uneventfully with conservative treatment. These successfully treated patients remain well, with a mean follow-up period of 20 months.

Conclusions: Postoperative matured T-tube tract ductal dilatation and stenting, combined with endoscopic electrohydraulic lithotripsy when indicated, is an effective and safe alternative to hepatic resection for selected left hepatolithiasis with intrahepatic biliary stricture.

Expression of a recombinant kringle V of human apolipoprotein(a): antibody characterization and species specificity

Lipoprotein(a) is a macromolecular complex consisting of a low-density lipoprotein-like particle with an additional glycoprotein, apolipoprotein(a) [apo(a)], linked to apolipoprotein B-100 via a disulfide bond. Apo(a) is highly homologous to plasminogen. We have cloned the sequence corresponding to the kringle V domain of apo(a) from human liver cDNA using an experimental approach involving use of the polymerase chain reaction. The protein product of this clone was expressed in the cytoplasmic compartment of Escherichia coli as a MalE fusion protein. Fusion apo(a) Kr V was isolated from cytoplasmic extracts and purified by amylose-agarose affinity chromatography by eluting with 10 mM maltose. The fusion protein was injected into sheep in order to generate a polyclonal anti-apo(a) Kr V antibody. The antibody raised reacted against both reduced Lp(a) and the C-terminal domain of apo(a), corresponding to a sequence extending from Kr 33 to the C-terminal residue, but did not react with the N-terminal domain containing the repeated Kr IV sequences. The presence of the Kr V sequence was detected in every human apo(a) size isoform tested but only in apo(a) from human and chimpanzee among a panel of apo(a) proteins derived from different animal species.

A case-control study of Salmonella gastrointestinal infection in Italian children

A case-control study of 85 cases with non-typhoid Salmonella gastroenteritis, 85 outpatient controls and 79 inpatient controls was conducted among children in Monfalcone, north-east Italy, between June 1989 and June 1994. Logistic regression was used to evaluate the effect of demographic and socio-economic characteristics, duration of breastfeeding, history of intestinal illnesses and household diarrhoea, and the recent use of antimicrobials. Breastfeeding was the single most important factor associated with a 5-fold decreased risk of Salmonella infection. In addition, children who were treated with antimicrobials before onset of gastroenteritis had a 3-fold increased risk. Low social class and history of other chronic non-infectious intestinal diseases were also directly associated with illness.

Hepatocyte growth factor expressed by a retrovirus-producing cell line enhances retroviral transduction of primary hepatocytes: implications for in vivo gene transfer

Hepatocyte Growth Factor (HGF) is the more potent mitogen of mature hepatocytes. We have examined the effect of human HGF expression by a recombinant retroviral cell line (MFG-LacZ) on retroviral transduction of primary mouse and human hepatocytes. The HGF in the supernatant of MFG-LacZ cell line was correctly processed and biologically active. Transduction of mouse and human hepatocytes with the supernatant of transfected cells was increased 5-fold, as determined by beta-galactosidase activity. The production of HGF was stable and did not interfere with the viral titers of the producer cells. This study provides evidence that expression of HGF within a retrovirus-producer cell line increases the transduction rate of primary hepatocytes. Since the number of corrected cells is a limiting step for phenotypic correction of liver deficiencies, our approach should improve hepatic gene therapy efficiency. Furthermore this cell line should be useful for in vivo liver gene therapy.

Primary cultured normal human hepatocytes for hepatitis B virus receptor studies

BACKGROUND/AIMS

We analyzed the hepatitis B virus envelope specificities (HBs, preS2 and preS1) involved in virus attachment to normal human hepatocytes, and we performed in vitro hepatitis B virus infection experiments without addition of dimethyl sulfoxide and polyethylene glycol, which may affect cell membrane integrity, in order to study further the early steps of the life cycle of the hepatitis B virus.

METHODS

Primary normal human hepatocytes were prepared from surgical biopsies by the two-step collagenase perfusion technique, and cultured in a fetal calf serum-free medium supplemented with 10(-6) M dexamethasone. Cell-binding assays, ligand blotting and immunohistochemistry experiments were carried out using our anti-idiotypic (Ab2) antibodies (Ab2s/preS1, Ab2s/preS2 and Ab2s/HBs).

RESULTS

Probing primary normal human hepatocytes, the 35-kDa major preS1-binding protein (preS1-BP35) we have previously identified in human hepatoma HepG2 cells was recognized in blotting, whereas both HBs- and preS1-specificities of the hepatitis B virus envelope interacted strongly with normal human hepatocyte cell membrane in cell-binding assays and immunohistochemistry experiments. Hepatitis B virus infectivity studies confirmed a great inter-experimental variability depending on donors and liver perfusion, and demonstrated a great intra-experimental variability depending on the serum-derived hepatitis B virus isolate used for the inoculation. In our culture conditions, only increased detection of the RC and CCC DNA forms of hepatitis B virus in cells and of hepatitis B virus surface antigens in medium was observed 4 to 8 days after exposure of cells to hepatitis B virus.

CONCLUSION

These findings support a potential role for preS1-BP35 as a receptor protein for hepatitis B virus. In our hands, limitation(s) in the hepatitis B virus life cycle may occur at some step after virion binding, and likely result from complex regulation of reverse transcription of the RNA and translation of core protein by extrahepatic host factors or/and by the virus itself. However, the normal human hepatocyte model developed here is available for studying the initial steps in hepatitis B virus entry into cells.

Comparison of a modified Sugiura procedure with portal systemic shunt for prevention of recurrent variceal bleeding in cirrhosis

BACKGROUND

There is no agreement on the management of patients with cirrhosis and recurrent variceal bleeding after failure of medical or endoscopic treatments or both. Portal systemic shunts are highly effective in preventing rebleeding but are associated with a high incidence of chronic encephalopathy. This study compared the results of a slightly modified Sugiura procedure (esophageal transection plus esophagogastric devascularization plus splenectomy) with those of nonselective portal systemic shunts in patients with previous variceal bleeding.

METHODS

Fifty-four patients were included in this randomized controlled study between January 1984 and April 1989. The major end point was chronic encephalopathy. Secondary end points were recurrent variceal bleeding, survival, ascites, and hepatocellular carcinoma.

RESULTS

Twenty-seven patients were assigned to each group. The rate of chronic encephalopathy was significantly (p = 0.002) lower after modified Sugiura procedure than after portal systemic shunt. Recurrent variceal bleeding was more frequent after modified Sugiura procedure than after portal systemic shunt, but the difference is not significant. One-, two-, and three-year survival rates were 93%, 81%, and 67%, respectively, in the modified Sugiura group and 78%, 66%, and 39%, respectively, in the portal systemic shunt group (p = 0.044).

CONCLUSIONS

These results suggest that the modified Sugiura procedure is better overall than the nonselective portal systemic shunt in the management of patients with cirrhosis and recurrent variceal bleeding. Although the rebleeding rate is higher after the modified Sugiura procedure, this does not seem to affect mortality in these patients.

Carcinosarcoma of the liver with mesenchymal differentiation: a case report

Carcinosarcoma of the liver with mesenchymal differentiation are very rare in adult patients. A case is reported with an exhaustive pathologic examination and review of the literature. A 61-year old man presented with general fatigue and dull abdominal pain. Two liver masses were diagnosed and resected by a right hepatectomy. Specimen pathology revealed that the tumor and lymph node consisted of two cancerous components. One carcinomatous component corresponding to a hepatocellular carcinoma and a sarcomatous component characterized by a diffuse proliferation of spindle shaped cells with chondrosarcomatous and osteosarcomatous changes. Patient died 9 months later of a diffusion of the tumor. For the first time, to our knowledge, a mesenchymal differentiation is demonstrated in liver carcinosarcoma.

An unusual cause for lumbar radiculopathy: a synovial facet joint cyst of the right L5 joint

OBJECTIVE

To report a rare cause of lumbar radiculopathy.

CLINICAL FEATURES

A 72-yr-old man suffered from pain that radiated down the posterior thigh and calf for 3 wk. The right foot and first toe extensors were weak and sensation was decreased over the dorsum of the foot. Straight leg raising was positive at 50 degrees on the right. Computed tomography with contrast revealed a large cyst with focal vacuum change with displacement of the dural sac at the L4-5 level.

INTERVENTION AND OUTCOME

An L4-5 laminectomy and facetectomy was performed with relief of the patient's complaint. The patient resumed full activity at 3 months.

CONCLUSION

An unusual cause of an L5 radiculopathy is discussed. Of the reported cases, surgical intervention has been the treatment of choice. Conservative treatment, including injections with corticosteroids and chiropractic management, have been reported to be successful. Further investigations using controls are needed to determine if conservative care is more cost-effective than surgical intervention.