Limits on light-speed anisotropies from Compton scattering of high-energy electrons

The possibility of anisotropies in the speed of light relative to the limiting speed of electrons is considered. The absence of sidereal variations in the energy of Compton-edge photons at the European Synchrotron Radiation Facility's GRAAL facility constrains such anisotropies representing the first nonthreshold collision-kinematics study of Lorentz violation. When interpreted within the minimal standard-model extension, this result yields the two-sided limit of 1.6×10(-14) at 95% confidence level on a combination of the parity-violating photon and electron coefficients (κ(o+))(YZ), (κ(o+))(ZX), c(TX), and c(TY). This new constraint provides an improvement over previous bounds by 1 order of magnitude.

[Appendiceal mucoceles, pseudomyxoma peritonei and appendiceal mucinous neoplasms: update on the contribution of imaging to choice of surgical approach]

INTRODUCTION

The treatment of pseudomyxoma peritonei (PMPs) and appendiceal mucocele (AM) has changed radically. To assess the contribution of preoperative imaging to the treatment strategy and choice of approach, a surgeon and a radiologist different from the initial radiologist examined the files of all patients treated for PMP or AM in four facilities in one district from January 1, 1996, through December 31, 2008.

PATIENTS AND METHODS

The study included 27 patients (20 men and seven women, mean age: 63+/-13 years). Eleven patients had an intact AM, seven synchronous PMP (malignant appendiceal lesion in two of seven), six metachronous PMP (five with peritoneal mucinous carcinomatosis and one with diffuse peritoneal adenomucinosis) and three a ruptured AM but not PMP. The incidence of mucin-secreting tumors observed (27 cases in 12 years in a region of 500 000 inhabitants) corresponds to a prevalence of approximately five cases per year per million inhabitants. Acute clinical pictures (7/27) were significantly more frequent for the malignant forms (5/7) (p<0,02).

RESULTS AND DISCUSSION

The overall sensitivity of computed tomography (CT) for all the criteria studied was 93%. The predictive value for AM rupture of visualization of thick calcifications was 100%. On the other hand, rupture never occurred when the CT showed an AM under pressure, with thin walls and septa. The predictive value for PMP of "scalloping" was 100%. The diagnostic accuracy of the initial reading was 25/27 for the imaging overall and 25/25 for the CT. Preoperative visualization of the exact size of the intact AM or of diagnostic information about ruptured AM and PMP helped to select an appropriate approach in 25 of 27 cases.

Direct measurement of the 7Be solar neutrino flux with 192 days of borexino data

We report the direct measurement of the 7Be solar neutrino signal rate performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso. The interaction rate of the 0.862 MeV 7Be neutrinos is 49+/-3stat+/-4syst counts/(day.100 ton). The hypothesis of no oscillation for 7Be solar neutrinos is inconsistent with our measurement at the 4sigma C.L. Our result is the first direct measurement of the survival probability for solar nu(e) in the transition region between matter-enhanced and vacuum-driven oscillations. The measurement improves the experimental determination of the flux of 7Be, pp, and CNO solar nu(e), and the limit on the effective neutrino magnetic moment using solar neutrinos.

Impact of antibiotic treatment on bacterial resistance rates from patients with hospital-acquired infection

We assessed the impact of antibiotic administration prior to sample collection on the bacterial resistance rates from patients with nosocomial infection. Every individual susceptibility report was assessed in real time at the bedside of the patient by a team composed of infectious diseases and internal medicine specialists as well as clinical microbiologists for clinical significance and appropriateness of the specimen. The report also stated the kind, source and origin of the infection, history of administration of any antibiotic during the last month prior to sample collection. To evaluate the impact of previous antibiotic administration, resistance rates were calculated separately among the group of patients with and without history of antibiotic treatment. A crude univariate analysis was performed to assess the significance of the differences between groups for every species-antibiotic pair. Patients who had received ciprofloxacin showed significantly higher rates of Escherichia coli resistant to ciprofloxacin, broad-spectrum cephalosporins and gentamicin. A higher rate of methicillin-resistant Staphylococcus aureus was observed in patients who were given gentamicin. A stratified analysis showed that the previous antibiotic administration continued to be a risk factor for increased resistance rates regardless of the hospital ward or the source of the infection. This study demonstrates the influence of previous antibiotic administration on bacterial resistance rates although this fact is barely taken into account by the laboratory when constructing the cumulative susceptibility data. Real time clinical validation of the individual susceptibility reports, performed by a multidisciplinary team prior to the data entering, might be a suitable approach to get more reliable susceptibility rates to guide the rational selection of antimicrobial empirical therapy in patients with hospital-acquired infections who have been given antimicrobial treatment prior to specimen collection.

Non-resident stem cell populations in regenerative cardiac medicine

The adult heart displays a low proliferation capacity, compromising its function if exposed to distinct biological insults. Interestingly, the observation that an increasing number of cell types display an unpredicted cellular plasticity has opened new therapeutical avenues. In this review we will summarize the current knowledge of non-resident stem cells that can be putatively used for cardiac regeneration. At present, bone marrow stem cells have been extensively studied as a cellular source to heal the heart; however, their myocardial contribution is highly limited. Experimental studies have demonstrated that skeletal myoblasts can engraft into the heart, although, unfortunately, they lead to myocardial uncoupling. Embryonic stem cells can spontaneously generate cardiomyocytes that exhibit a variety of electrophysiological phenotypes. Several constrains should nonetheless be overcome before entering the clinical arena, such as the ability to direct and control the generation of cardiomyocytes into a single myocardial lineage.

Treatment of tumour recurrence after resection of hepatocellular carcinoma. Analysis of 97 consecutive patients

OBJECTIVE

To evaluate the long-term results of aggressive treatment of HCC recurrence.

METHODS

Two hundred and nine consecutive patients underwent hepatic resection for HCC in our hospital. Tumour recurrence was diagnosed in 97 (51%) of the 190 patients with curative resection. Sixteen underwent hepatic resection: two right hepatectomies, one three-segmentectomy, one left hepatectomy, five two-segmentectomies, six segmental resections and one subsegmentectomy. Two patients with metastasis in the spine were submitted to a vertebral body resection. Twenty-five patients were treated with percutaneous ethanol injection or intra-arterial chemoembolization. Fifty-four patients with a poor performance status and liver function or multiple extra hepatic recurrences did not receive any treatment.

RESULTS

There were no operative deaths. The postoperative mortality rate was 5.5% (one patient). The cumulative overall survival after the second resection was respectively 89%, 46% and 31% at 1, 3 and 5 years. There was a significant difference in survival between patients treated with repeat resection and those submitted to a non-surgical or conservative treatment (p<0.0001). There were no differences in operative deaths, postoperative mortality and morbidity between the first and second hepatic resection.

CONCLUSIONS

Aggressive management with combined resection or loco regional therapy for intrahepatic recurrence and resection of isolated extra-hepatic recurrence may offer long-term survival in selected patients. Second liver resection for recurrence of HCC can be safely performed.

Resection of hepatocellular carcinoma: the effect of surgical margin and blood transfusion on long-term survival. Analysis of 209 consecutive patients

BACKGROUND/AIMS

Certain prognostic factors affect the postoperative mortality and long-term survival of patients following hepatic resection for hepatocellular carcinoma (HCC) and may change the surgical strategy.

METHODOLOGY

209 consecutive patients underwent hepatic resection for HCC in our hospital. Seventy-three patients underwent major resection and 136 underwent minor resections. We looked for correlations between clinical, biological, surgical and pathological factors and postoperative mortality, disease-free survival and overall survival.

RESULTS

The postoperative mortality rate was 7.7% (it fell to 0% in the last two years). The cumulative overall five-year survival rate was 27% and the overall disease-free survival rate was 7.3%. Multivariate analysis identified: (1) two independent prognostic factors for postoperative mortality: age and tumor size; (2) one risk factor for tumor recurrence: intraoperative blood transfusion, and (3) three independent prognostic factors for overall survival: infiltrative tumor type, surgical margin <10 mm and intraoperative blood transfusion.

CONCLUSIONS

In addition to routine staging of the tumor, the preoperative evaluation of HCC patients should include tests to determine whether the tumor is infiltrative or expansive and whether it will be possible to obtain a surgical margin (>10 mm). This procedure should make it possible to propose an appropriate neoadjuvant treatment only to these patients. The prevention of intraoperative bleeding or blood transfusion should improve the disease-free and overall survival rates in HCC patients.

Laparoscopic liver resection: results for 70 patients

BACKGROUND

Laparoscopy is slowly becoming an established technique for liver resection. This procedure still is limited to centers with experience in both hepatic and laparoscopic surgery. Preliminary reports include mainly minor resections for benign liver conditions and show some advantage in terms of postoperative recovery. The authors report their experience with laparoscopic liver resection, the evolution of the technique, and the results.

METHODS

From 1999 to 2006, 70 laparoscopic liver resections were performed using a procedure similar to resection by laparotomy.

RESULTS

There were 38 malignant tumors (54%) and 32 benign lesions (46%). The malignant tumors were mainly hepatocellular carcinomas (19 of 24 patients had cirrhosis). The tumor mean size was 3.8 +/- 1.9 cm (range, 2.2-8 cm). There were 19 major hepatectomies, 34 uni- or bisegmentomies, and 17 atypical resections. The operative time was 227 +/- 109 min. Conversion to laparotomy was required for seven patients (10%), mainly for continuous bleeding during transection. Nine patients (13%) required blood transfusion. One patient had both brisk bleeding and gas embolism from a tear in the section line of the right hepatic vein requiring laparoscopic suture. Blood loss and transfusion requirements were significantly lower in recent than in early cases and in resections with prior vascular control than in those without such control. Postoperative complications were experienced by 11 patients (16%), including one bleed from the hepatic stump requiring hemostasis and two subphrenic collections requiring percutaneous drainage. One cirrhotic patient died of liver failure after resection of a partially ruptured tumor. No ascites was observed in other cirrhotic patients. The mean hospital stay was 5.9 days.

CONCLUSION

The study results confirm that laparoscopic liver resection, including major hepatectomies, can be safely performed by laparoscopy.

Alternative Indicators for Monitoring the Quality of a Continuous Intervention Program on Antibiotic Prescribing during Changing Healthcare Conditions

We recently published on the impact of a four-phase hospital-wide intervention program designed to optimize the quality of antibiotic use, where a multidisciplinary team (MDT) could modify prescription at the last phase. Because health care quality was changing during the last 5 years (late 1999 to early 2004), we developed certain indicators to monitor the quality of our intervention over time. Different periods were defined as baseline (pre-intervention), initial intervention-active control, pre-crisis control, crisis control, post-crisis control and end of crisis control. Major indicators were rates of prescription modification by the MDT; prescription for an uncertain infection and a novel index formula (RIcarb) to estimate the rationale for carbapenem use. We assessed 2115 antimicrobial prescriptions. Modification of prescription rate was 30% at the beginning and decreased thereafter up to stable levels. Rate of prescriptions ordered for cases of both uncertain infection and unknown source of infection decreased significantly after intervention (i.e. from baseline to active control). In contrast, a doubling of culture-directed prescriptions was observed between these periods. RIcarb values lower and higher than 60% (modal, cut-off) were assumed as carbapenem overuse and underuse, respectively. Overuse was observed at the pre-intervention, while pronounced underuse was shown during the crisis (RIcarb, 45% and 87%, respectively). The present study demonstrates that certain indicators, other than the widely adopted impact outcomes, are a suitable tool for monitoring the quality of a continuous, long-term, active intervention on antimicrobial prescribing practice, especially when applied in a changing healthcare setting.

Low-cost laparoscopic cholecystectomy

BACKGROUND

Hospital managers are continually trying to decrease the cost of patient care. The aim of this prospective study was to propose changes that would decrease the operating room costs of laparoscopic cholecystectomy without affecting clinical results.

METHODS

The study included 112 consecutive patients who underwent an elective cholecystectomy between January 1997 and December 2000. The procedure was changed in eight ways: the American position, open laparoscopy, reusable trocars, reusable instruments, bipolar coagulation of the cystic artery, intracorporeal ligature of the cystic duct, no use of suction lavage apparatus, and use of a surgical glove as a bag to extract the gallbladder. Complete compliance with the procedure, whether any abnormal operative events or complications occurred, the duration of hospitalization, and the material and labour costs of the procedure were recorded.

RESULTS

There were no abnormal operative events. Only two patients suffered from postoperative complications. The mean duration of hospitalization was 55.8 h. Fifteen patients (13.4 per cent) were not hospitalized overnight. The operating costs fell from 560 euros before the study to 330 euros in 2000.

CONCLUSION

By applying simple measures, it is possible to decrease the operating room cost of laparoscopic cholecystectomy whilst maintaining good results. Such measures should be applied to other laparoscopic procedures.

Efficacy of amoxicillin-sulbactam, given twice-a-day, for the treatment of community-acquired pneumonia: a clinical trial based on a pharmacodynamic model

The present multicenter study reports the results of a clinical trial, designed on the basis of a pharmacodynamic study published previously (Bantar et al., J. Chemother 2000; 12: 223-227) to assess the efficacy of amoxicillin/sulbactam (875 mg/125 mg), given orally twice-a-day for 7 days in the treatment of patients with community-acquired pneumonia (CAP). Eighty-four evaluable subjects older than 19 years with clinical symptoms and features suggestive of CAP, consulting from June 2000 to March 2002 and meeting the PORT risk class I through III, were enrolled in the study. Mean age (y +/- standard deviation) was 46.7 +/- 16.3 and 62% of the patients had some co-morbidity predisposing for CAP. Several individuals (77.4%) fell into a low-risk class (i.e. PORT I or II) and 22.6% of patients belonged to a moderate-risk class at the start of treatment. Six patients (6.45%) had pneumococcal bacteremia. Streptococcus pneumoniae was the organism most frequently isolated (61.9% of all the patients in whom an etiologic diagnosis was made), followed by Haemophilus influenzae. Clinical success was observed in 97.6% of the patients (confidence interval 95%, 94.3%-100%). Almost all the individuals with clinical success became afebrile within the first 3 days of therapy. Ten patients (11.8%) reported mild or moderate adverse events (especially diarrhea) possibly related to the antimicrobial therapy, but this did not lead to withdrawal from the trial. The results of this study suggest that amoxicillin/sulbactam (875 mg/125 mg) is an efficacious and well tolerated option for treating patients with CAP belonging to a low-moderate risk class and support the use of a short, oral (7-day) b.i.d. regimen.

[Peri-hepatitis abscess secondary to pelvic peritonitis]

OBJECTIVE

To report the case of a 42-year-old patient referred for exploration of a tumor of the right flank and evidence of inflammation.

MATERIAL

and methods. Ultrasonography and computed tomography showed a liver mass associated with a heterogeneous adnexal mass. Serum CA-125 was elevated and ovarian cancer with liver metastasis was suspected. An alternative diagnosis was salpingitis complicated by Fitz-Hugh-Curtis syndrome in this patient wearing an intra-uterine contraceptive device.

RESULTS

Exploratory laparoscopy was performed and confirmed the diagnosis of salpingitis complicated by an ovarian abscess and Fitz-Hugh-Curtis syndrome with rare abscess formation. Outcome was favorable after adapted antibiotic treatment.

CONCLUSION

Fitz-Hugh-Curtis syndrome can take on an atypical aspect and should be entertained as a possible diagnosis in young women presenting pain of the right flank and fever.

[Allotransplantation in utero and immortalization of primate fetal hepatocytes]

We are developing cell therapy approaches on non-human primates as a preclinical model for the treatment of hepatic metabolic diseases. In foetuses, the tissues, including liver, are in expansion, which should facilitate hepatocytes engraftment, and the immune system becomes fully mature only after birth. We have set out conditions for isolation of fetal hepatocytes from macaca mulatta at the end of the 2nd trimester of gestation (90-100 days), their cryopreservation and retroviral transduction. Two different routes of administration of hepatocytes were evaluated: the umbilical vein which was deleterious for the foetuses, and the intraparenchymatous injection which was well tolerated by the animals. Administration of hepatocytes into the hepatic parenchyma resulted in microchimerism and allogenic cells were visualized 9 days after transplantation. Another approach has been to immortalize simian foetal hepatocytes using a retroviral vector expressing SV40 Large T flanked by lox sites. A cell line has been established for 2 years, which is not tumorigenic when injected subcutaneously into nude mice and display characteristics of bipotent hepatoblasts, precursors of hepatocytes and biliary cells. After orthotopic transplantation into nude mice via the portal vein, these cells expressed albumin until the sacrifice of the animals (17 days). The next steps will be to define conditions for transplantation of retrovirally transduced fetal primary and/or immortalized hepatocytes into young foetuses (60 days of gestation) and post-natally.

Divergent expression of delayed rectifier K(+) channel subunits during mouse heart development

The repolarization phase of the cardiac action potential is dependent on transmembrane K(+) currents. The slow (I(Ks)) and fast (I(Kr)) components of the delayed-rectifier cardiac K(+) current are generated by pore-forming alpha subunits KCNQ1 and KCNH2, respectively, in association with regulatory beta-subunit KCNE1, KCNE2 and perphaps KCNE3. In the present study we have investigated the distribution of transcripts encoding these five potassium channel-forming subunits during mouse heart development as well as the protein distribution of KCNQ1 and KCNH2. KCNQ1 and KCNH2 mRNAs (and protein) are first expressed at embryonic day (E) 9.5, showing comparable levels of expression within the atrial and ventricular myocardium during the embryonic and fetal stages. In contrast, the beta-subunits display a more dynamic pattern of expression during development. KCNE1 expression is first observed at E9.5 throughout the entire myocardium and progressively is confined to the ventricular myocardium. With further development (E16.5), KCNE1 expression is mainly confined to the compact ventricular myocardium. KCNE2 is first expressed at E9.5 and it is restricted already to the atrial myocardium. KCNE3 is first expressed at E8.5 throughout the myocardium and with further development, it becomes restricted to the atrial myocardium. The fact that alpha subunits are homogeneously distributed within the myocardium, whereas the beta subunits display a regionalized expression profile during cardiac development, suggest that differences in the slow and fast component of the delayed-rectifier cardiac K(+) currents between the atrial and the ventricular cardiomyocytes are mainly determined by differential beta-subunit distribution.

Transplantation of hepatocytes in nonhuman primates: a preclinical model for the treatment of hepatic metabolic diseases

BACKGROUND

The transplantation of isolated hepatocytes in large animals, including nonhuman primates, must be evaluated before clinical trials are performed. However, in the absence of large transgenic animals and large-animal (as opposed to small-animal) models of genetic deficiencies, it is difficult to evaluate the fate of transplanted hepatocytes, their localization, survival, and function within the parenchyma of the host liver. In this work, we aimed to develop a technique for delivering hepatocytes to the liver of a nonhuman primate and to evaluate their localization and functionality in the short term.

METHODS

A 20% hepatectomy was performed in 34 cynomolgus monkeys (Macaca fascicularis) and hepatocytes were isolated. Hepatocytes were labeled in vitro with a recombinant retrovirus expressing the beta-galactosidase gene and returned to the liver by infusion through a portal catheter left in place. Liver biopsies were performed 4 and 7 d after transplantation.

RESULTS

Twenty-four monkeys underwent surgery to define the necessary technical adjustments and to optimize conditions. Six monkeys died. The whole protocol, including the transplantation of genetically marked hepatocytes and procurement of liver biopsies, was performed in the remaining 10 monkeys. In eight monkeys, transplanted hepatocytes expressing the beta-galactosidase gene were widely distributed in the portal tracts, sinusoids, and hepatocyte plates of the host liver 4 and 7 d after transplantation.

CONCLUSIONS

We have developed an experimental nonhuman primate model for the evaluation of hepatocyte transplantation. We demonstrated the engraftment and functioning of transplanted hepatocytes in the host liver 4 and 7 d after transplantation.

Genetic alterations associated with hepatocellular carcinomas define distinct pathways of hepatocarcinogenesis

BACKGROUND & AIMS

To evaluate how characterization of genetic alterations can help in the elucidation of liver carcinogenesis pathways, 137 tumors were analyzed.

METHODS

High-density allelotype, p53, Axin1, and beta-catenin gene mutations were determined. Alterations were analyzed according to clinical parameters.

RESULTS

Tumors could be divided into 2 groups according to chromosome stability status. In the first group, demonstrating a chromosome stability, beta-catenin mutation associated with chromosome 8p losses were frequently found as the single genetic alterations. beta-catenin mutations were associated with large tumor size and with negative hepatitis B virus status. In the second group, demonstrating a chromosome instability, the most frequent allelic losses were on chromosome 1p, 4q, 6q, 9p, 13q, 16p, 16q, and 17p; Axin1 and p53 were frequently mutated. All of these alterations, except losses on 6q and 9p, were associated with hepatitis B virus infection. P53 mutations, 17p, 13q losses, and a high value of the fractional allelic loss index were associated with poor differentiated tumors, independently of risk factors. Finally, in the whole series, chromosome 9p and 6q losses were associated with poor prognosis.

CONCLUSIONS

Two main pathways defined by genetic alterations show different risk factors and clinical characteristics. Furthermore, loss of chromosome 9p or 6q is an independent prognostic indicator.

Pitx2 expression defines a left cardiac lineage of cells: evidence for atrial and ventricular molecular isomerism in the iv/iv mice

The homeobox gene Pitx2 has been characterized as a mediator of left-right signaling in heart, gut, and lung morphogenesis. However, the relationship between the developmental role of Pitx2 and its expression pattern at the organ level has not been explored. In this study we focus on the role of Pitx2 in heart morphogenesis. Chicken Pitx2 transcripts are present in the left portion of the cardiac crescent and in the left side of the heart tube. Through looping Pitx2 is present in the left atrium, in the ventral portion of the ventricles and in the left-ventral part of the outflow tract. Mouse Pitx2 shows a similar developmental profile of expression. To test whether Pitx2 represents a lineage marker we have tagged the left portion of the chicken cardiac tube with fluorescent DiD. Labeled cells were found at HH16 in the left atrium and in the ventral region of the ventricles and the outflow tract. In the iv/iv mouse model of cardiac heterotaxia Pitx2 was abnormally expressed in the atrial and in the ventricular chambers. Furthermore, altered Pitx2 expression correlated with the occurrence of DORV. Our data reveal the existence of molecular isomerism not only in the atrial, but also in the ventricular compartment of the heart.

Differential expression of KvLQT1 and its regulator IsK in mouse epithelia

KCNQ1 is the human gene responsible in most cases for the long QT syndrome, a genetic disorder characterized by anomalies in cardiac repolarization leading to arrhythmias and sudden death. KCNQ1 encodes a pore-forming K+ channel subunit termed KvLQT1 which, in association with its regulatory beta-subunit IsK (also called minK), produces the slow component of the delayed-rectifier cardiac K+ current. We used in situ hybridization to localize KvLQT1 and IsK mRNAs in various tissues from adult mice. We showed that KvLQT1 mRNA expression is widely distributed in epithelial tissues, in the absence (small intestine, lung, liver, thymus) or presence (kidney, stomach, exocrine pancreas) of its regulator IsK. In the kidney and the stomach, however, the expression patterns of KvLQT1 and IsK do not coincide. In many tissues, in situ data obtained with the IsK probe coincide with beta-galactosidase expression in IsK-deficient mice in which the bacterial lacZ gene has been substituted for the IsK coding region. Because expression of KvLQT1 in the presence or absence of its regulator generates a K+ current with different biophysical characteristics, the role of KvLQT1 in epithelial cells may vary depending on the expression of its regulator IsK. The high level of KvLQT1 expression in epithelial tissues is consistent with its potential role in K+ secretion and recycling, in maintaining the resting potential, and in regulating Cl- secretion and/or Na+ absorption.

Molecular characterization of the ventricular conduction system in the developing mouse heart: topographical correlation in normal and congenitally malformed hearts

OBJECTIVES

Within the adult heart, it is convention to distinguish the conduction system and working (atrial and ventricular) myocardium. The adult conduction system (CS) comprises the sinoatrial (SAN), and atrioventricular (AVN) nodes, the atrioventricular bundle (AVB), the bundle branches and the peripheral Purkinje fibers, each of which display distinct functional properties and distinct profile of gene expression. Characterization of the mouse cardiac conduction system during development is rudimentary at present, even though genetically-modified mice are an increasing source of information regarding cardiac function and embryonic heart development.

METHODS

We have performed a detailed study of the pattern of expression of myosin heavy chain (MHC), myosin light chain (MLC), troponin I (TnI) isoforms, connexin 43 (Cx43), desmin and alpha-smooth muscle actin (alpha-SMA), in the ventricular conduction system of normal and congenitally malformed mouse hearts (iv background) from embryonic day 14.5 to 19.5.

RESULTS

The AVN is characterized by co-expression of MHC and MLC isoforms and no detectable expression of Cx43, desmin or alpha-SMA. The AVB expresses betaMHC and MLC2v, but no alphaMHC, MLC2a, Cx43, desmin or alpha-SMA. The right and left bundle branches display enhanced expression of desmin and alpha-SMA but no Cx43. The normal expression profile is maintained in congenitally malformed hearts such as double-outlet right ventricle and common atrioventricular canal. Three-dimensional reconstruction of the conduction system shows normal arrangement of the bundle branches in congenitally malformed hearts, but abnormal location and/or extension of the AVN.

CONCLUSIONS

Molecular characterization allows to follow the development of the CS in both, normal and malformed mouse hearts. Normal phenotypic expression of the CS is independent of heart situs but shows minor modifications in the presence of heart malformations. It is concluded that the AVN derives from the atrioventricular canal myocardium, the bundle of His from the ventricular myocardium, and the bundle branches from the ventricular trabeculations. Our results do not provide evidence to support an extra-cardiac origin of the ventricular CS.

Engraftment of autologous retrovirally transduced hepatocytes after intraportal transplantation into nonhuman primates: implication for ex vivo gene therapy

The main impediment to effective ex vivo liver gene therapy of metabolic diseases is the lack of experimental work on large animals to resolve such important issues as effective gene delivery, cell-processing techniques, and the development of appropriate vectors. We have used a nonhuman primate, as a preclinical model, to analyze the limiting steps of this approach using recombinant retroviruses. Seven monkeys (Macaca fascicularis) underwent the complete protocol: their left liver lobe was resected, a catheter was placed in the inferior mesenteric vein and connected to an infusion chamber, and the hepatocytes were isolated, cultured, and transduced with a retroviral vector containing the beta-galactosidase gene. The hepatocytes were harvested and returned to the host via the infusion chamber. Biopsies were taken 4-40 days later. No animal was killed in the course of the experiments. They all tolerated the procedure well. We have developed and defined conditions that permit the proliferation and transduction of up to 90% of the plated hepatocytes. A significant proportion of genetically modified cells, representing up to 3% of the liver mass, were safely delivered to the liver via the chamber. Polymerase chain reaction analysis detected integrated viral DNA sequences and quantitative analysis of the in situ beta-Gal-expressing hepatocytes indicated that a significant amount of transduced hepatocytes, up to 2%, had become integrated into the liver and were functional. These results represent substantial advances in the development of the ex vivo approach and suggest that this approach is of clinical relevance for liver-directed gene therapy.

Resection of hepatocellular carcinoma

The majority of hepatocellular carcinoma occurs in patients with liver cirrhosis. Although the tumors are often discovered at an early stage during surveillance of these patients, the underlying cirrhosis renders the surgery more difficult and exposes the patients to higher rates of postoperative morbidity and mortality than occurs in other types of liver surgery. Over the past 20 years surgeons have developed new surgical procedures and techniques to firstly reduce the unnecessary resection of liver parenchyma and to decrease intraoperative blood loss. Better patient selection and understanding of prognostic factors will hopefully result in a further decrease in operative risk and postoperative recurrence. Adjuvant chemotherapy may prove effective in reducing the postoperative recurrence but at this stage surgery still remains as the best treatment for patients with recurrent tumor which is accessible to resection.

Surgery for cholangiocarcinoma

Cholangiocarcinoma is a cancer arising from bile duct epithelium and commonly occurs in the main bile duct or at the bile duct confluence. The patients present obstructive jaundice and often have advanced disease. Treatment in the past has frequently consisted of palliative measures aimed at relieving jaundice either by surgical bypass or by endoscopic or percutaneous drainage usually in combination with stenting. A better understanding of the ways of invasion of the pathology of cholangiocarcinoma together with improvements in surgical techniques and perioperative management have lead to an increase in the number of patients in whom resection may be contemplated. Resection offers the only chance of cure and the best chance of long-term survival. Current problems associated with resection of hilar cholangiocarcinoma are discussed in this review article.

MLC3F transgene expression iniv mutant mice reveals the importance of left-right signalling pathways for the acquisition of left and right atrial but not ventricular compartment identity

Abstract Transcriptional differences between left and right cardiac chambers are revealed by an nlacZ reporter transgene controlled by regulatory sequences of the MLC3F gene, which is expressed in the left ventricle (LV), atrioventricular canal (AVC), and right atrium (RA). To examine the role of left-right signalling in the acquisition of left and right chamber identity, we have investigated MLC3F transgene expression in iv mutant mice. iv/iv mice exhibit randomised direction of heart looping and an elevated frequency of associated laterality defects, including atrial isomerism. At fetal stages, 3F-nlacZ-2E transgene expression remains confined to the morphological LV, AVC, and RA in L-loop hearts, although these appear on the opposite side of the body. In cases of morphologically distinguishable right atrial appendage isomerism, both atrial appendages show strong transgene expression. Conversely, specimens with morphological left atrial appendage isomerism show only weak expression in both atrial appendages. The earliest left-right atrial differences in the expression of the 3F-nlacZ-2E transgene are observed at E8.5. DiI labelling experiments confirmed that transcriptional regionalisation of the 3F-nlacZ-2E transgene at this stage reflects future atrial chamber identity. In some iv/iv embryos at E8.5, the asymmetry of 3F-nlacZ-2E expression was lost, suggesting atrial isomerism at the transcriptional level prior to chamber formation. These data suggest that molecular specification of left and right atrial but not ventricular chambers is dependent on left-right axial cues.

[Gallstones and their complications]

Gallbladder stones are present in more than 10% of the population in Europe, particularly in women. Most patients are and will remain asymptomatic. No treatment is required. Patients with gallstones and biliary colics should have elective laparoscopic cholecystectomy which can be performed in almost every case. Acute gall-stone cholecystitis is the most severe complication. It should prompt urgent cholecystecomy that can be done by laparoscopy. Other complications such as biliobiliary fistulas have become unfrequent.

Multiple transcriptional domains, with distinct left and right components, in the atrial chambers of the developing heart

During heart development, 2 fast-conducting regions of working myocardium balloon out from the slow-conducting primary myocardium of the tubular heart. Three regions of primary myocardium persist: the outflow tract, atrioventricular canal, and inflow tract, which are contiguous throughout the inner curvature of the heart. The contribution of the inflow tract to the definitive atrial chambers has remained enigmatic largely because of the lack of molecular markers that permit unambiguous identification of this myocardial domain. We now report that the genes encoding atrial natriuretic factor, myosin light chain (MLC) 3F, MLC2V, and Pitx-2, and transgenic mouse lines expressing nlacZ under the control of regulatory sequences of the mouse MLC1F/3F gene, display regionalized patterns of expression in the atrial component of the developing mouse heart. These data distinguish 4 broad transcriptional domains in the atrial myocardium: (1) the atrioventricular canal that will form the smooth-walled lower atrial rim proximal to the ventricles; (2) the atrial appendages; (3) the caval vein myocardium (systemic inlet); and (4) the mediastinal myocardium (pulmonary inlet), including the atrial septa. The pattern of expression of Pitx-2 reveals that each of these transcriptional domains has a distinct left and right component. This study reveals for the first time differential gene expression in the systemic and pulmonary inlets, which is not shared by the contiguous atrial appendages and provides evidence for multiple molecular compartments within the atrial chambers. Furthermore, this work will allow the contribution of each of these myocardial components to be studied in congenitally malformed hearts, such as those with abnormal venous return.

Activation of V(D)J recombination induces the formation of interlocus joints and hybrid joints in scid pre-B-cell lines

V(D)J recombination is the mechanism by which antigen receptor genes are assembled. The site-specific cleavage mediated by RAG1 and RAG2 proteins generates two types of double-strand DNA breaks: blunt signal ends and covalently sealed hairpin coding ends. Although these DNA breaks are mainly resolved into coding joints and signal joints, they can participate in a nonstandard joining process, forming hybrid and open/shut joints that link coding ends to signal ends. In addition, the broken DNA molecules excised from different receptor gene loci could potentially be joined to generate interlocus joints. The interlocus recombination process may contribute to the translocation between antigen receptor genes and oncogenes, leading to malignant transformation of lymphocytes. To investigate the underlying mechanisms of these nonstandard recombination events, we took advantage of recombination-inducible cell lines derived from scid homozygous (s/s) and scid heterozygous (s/+) mice by transforming B-cell precursors with a temperature-sensitive Abelson murine leukemia virus mutant (ts-Ab-MLV). We can manipulate the level of recombination cleavage and end resolution by altering the cell culture temperature. By analyzing various recombination products in scid and s/+ ts-Ab-MLV transformants, we report in this study that scid cells make higher levels of interlocus and hybrid joints than their normal counterparts. These joints arise concurrently with the formation of intralocus joints, as well as with the appearance of opened coding ends. The junctions of these joining products exhibit excessive nucleotide deletions, a characteristic of scid coding joints. These data suggest that an inability of scid cells to promptly resolve their recombination ends exposes the ends to a random joining process, which can conceivably lead to chromosomal translocations.

Evaluation of extracts from Gevuina avellana hulls as antioxidants

The antioxidant activity of the extracts from Gevuina avellana hulls was evaluated and compared with that of BHT (butylated hydroxytoluene) and BHA (butylated hydroxyanisole), using the beta-carotene bleaching assay, the accelerated oxidation of crude soybean oil, and the 2,2-diphenyl-beta-picrylhydrazyl (DPPH) radical scavenging method. Solvents of different polarity were used to obtain the extracts. Both the extraction yield and the antioxidant activity were strongly dependent on the solvent. The ethanol and diethyl ether soluble fractions were the most active with the beta-carotene assay. Ethanol and methanol extracts were the most active in hydrogen radical scavenging activity. Water and methanol inhibited more efficiently the oxidation of soybean oil at 70 and 80 degrees C, respectively. As a general trend, increased antioxidant activity was observed for increased extract concentration. Except the acetone extracts, all were stable after 6 months storage at 4 degrees C. The ethanol solubles from G. avellana hulls present antioxidant activity similar to that of synthetic antioxidants and to other reported residual agroindustrial materials.

An atrioventricular canal domain defined by cardiac troponin I transgene expression in the embryonic myocardium

During early cardiac development the atrial myocardium is continuous with the ventricular myocardium throughout the atrioventricular canal. The atrioventricular canal undergoes complex remodelling involving septation, formation of atrioventricular valves and insulation between atria and ventricles except at the level of the atrioventricular node. Understanding of these processes has been hampered by the lack of markers specific for this heart region. We have generated transgenic mice expressing beta-galactosidase under the control of the cardiac troponin I gene that show transgene expression mainly confined to the atrioventricular canal myocardium during early embryonic development. With further development beta-galactosidase positive cells are observed in the atrioventricular node and in the lower rim of both right and left atria, supporting the view that atrioventricular canal myocardium contributes to the atrioventricular node and is in part incorporated into the lower rim of the atria. These results identify the atrioventricular canal myocardium as a distinct transcriptional domain.

Chamber formation and morphogenesis in the developing mammalian heart

In this study we challenge the generally accepted view that cardiac chambers form from an array of segmental primordia arranged along the anteroposterior axis of the linear and looping heart tube. We traced the spatial pattern of expression of genes encoding atrial natriuretic factor, sarcoplasmic reticulum calcium ATPase, Chisel, Irx5, Irx4, myosin light chain 2v, and beta-myosin heavy chain and related these to morphogenesis. Based on the patterns we propose a two-step model for chamber formation in the embryonic heart. First, a linear heart forms, which is composed of "primary" myocardium that nonetheless shows polarity in phenotype and gene expression along its anteroposterior and dorsoventral axes. Second, specialized ventricular chamber myocardium is specified at the ventral surface of the linear heart tube, while distinct left and right atrial myocardium forms more caudally on laterodorsal surfaces. The process of looping aligns these primordial chambers such that they face the outer curvature. Myocardium of the inner curvature, as well as that of inflow tract, atrioventricular canal, and outflow tract, retains the molecular signature originally found in linear heart tube myocardium. Evidence for distinct transcriptional programs which govern compartmentalization in the forming heart is seen in the patterns of expression of Hand1 for the dorsoventral axis, Irx4 and Tbx5 for the anteroposterior axis, and Irx5 for the distinction between primary and chamber myocardium.

Analgesic effect of low-dose intrathecal morphine and bupivacaine in laparoscopic cholecystectomy

We assessed the peri-operative analgesic efficiency of low-dose intrathecal morphine combined with a low dose of bupivacaine after elective laparoscopic cholecystectomy since postoperative pain in such procedures, although less than after a conventional open technique, may be significant, particularly during the first 12-24 h. After informed consent, 34 ASA I or II patients were randomly allocated to one of two groups to receive either a lumbar intrathecal injection of morphine (75 or 100 microg) combined with 5 mg of isobaric bupivacaine (spinal group) or a subcutaneous injection of a saline solution (control group). Intra-operatively, opioid requirements, blood pressure response and heart rate changes after insufflation were recorded. Postoperatively, morphine requirements, pain scores and opioid-related side-effects were assessed by a physician blinded to the randomisation. Intra-operative opioid requirements did not differ significantly between groups. Mean (SD) postoperative morphine requirements were significantly lower in the spinal group [13 (10) vs. 23 (10) mg; p = 0.04] as were postoperative pain scores (p < 0.001). Side-effects were of comparable incidence and severity between groups. Low-dose intrathecal morphine combined with low-dose bupivacaine provided effective postoperative analgesia for elective laparoscopic cholecystectomy.