Get in and get out: Remodeling of the cellular actin cytoskeleton upon HIV-1 infection

The human immunodeficiency virus type 1 (HIV-1) is an intracellular pathogen whose replication cycle strictly depends on the host cell molecular machinery. HIV-1 crosses twice the plasma membrane, to get in and to get out of the cell. Therefore, the first and the last line of intracellular component encountered by the virus is the cortical actin network. Here, we review the role of actin and actin-related proteins in HIV-1 entry, assembly, budding, and release. We first highlight the mechanisms controlling actin polymerization at the entry site that promote the clustering of HIV-1 receptors, a crucial step for the virus to fuse with the plasma membrane. Then, we describe how actin is transiently depolymerized locally to allow the capsid to cross the actin cortex, before migrating towards the nucleus. Finally, we review the role of several actin-binding proteins in actin remodeling events required for membrane deformation and curvature at the viral assembly site as well as for virus release. Strikingly, it appears that common actin-regulating pathways are involved in viral entry and exit. However, while the role of actin remodeling during entry is well understood, this is not the case during exit. We discuss remaining challenges regarding the actin-dependent mechanisms involved in HIV-1 entry and exit, and how they could be overcome.

Oxidation and reduction of actin: Origin, impact in vitro and functional consequences in vivo

Actin is among the most abundant proteins in eukaryotic cells and assembles into dynamic filamentous networks regulated by many actin binding proteins. The actin cytoskeleton must be finely tuned, both in space and time, to fulfill key cellular functions such as cell division, cell shape changes, phagocytosis and cell migration. While actin oxidation by reactive oxygen species (ROS) at non-physiological levels are known for long to impact on actin polymerization and on the cellular actin cytoskeleton, growing evidence shows that direct and reversible oxidation/reduction of specific actin amino acids plays an important and physiological role in regulating the actin cytoskeleton. In this review, we describe which actin amino acid residues can be selectively oxidized and reduced in many different ways (e.g. disulfide bond formation, glutathionylation, carbonylation, nitration, nitrosylation and other oxidations), the cellular enzymes at the origin of these post-translational modifications, and the impact of actin redox modifications both in vitro and in vivo. We show that the regulated balance of oxidation and reduction of key actin amino acid residues contributes to the control of actin filament polymerization and disassembly at the subcellular scale and highlight how improper redox modifications of actin can lead to pathological conditions.

Usefulness of Plasma SARS-CoV-2 RNA Quantification by Droplet-based Digital PCR to Monitor Treatment Against COVID-19 in a B-cell Lymphoma Patient

We report the case of an HIV-1-infected patient, treated with anti-CD20 monoclonal antibody for a B-cell lymphoma previously treated by autologous stem cell transplant. He suffered from chronic COVID19 and we monitored by plasma SARS-CoV-2 RNA by highly sensitive droplet-based digital PCR technology (ddPCR). Under tocilizumab therapy and despite a first clinical improvement biologically associated with decreasing inflammatory markers, a slight increase of SARS-CoV-2 RNAaemia quantified by ddPCR was highlighted, confirming the absence of viral efficacy of this treatment and predicting the subsequent observed deterioration. As expected, his complete recovery, finally achieved after COVID-19 convalescent plasmatherapy, strictly paralleled plasma SARS-CoV-2 RNA clearance. With these results, we confirmed the interest of SARS-CoV-2 RNAaemia monitoring by ddPCR in COVID-19 patients, particularly during treatment, and firstly showed that this new and specific biomarker could be helpful to select eligible patient for anti-IL6 receptors therapy considering the variable levels of efficacy recently observed with such therapy.

Multidisciplinary consensus statement on the clinical management of patients with pancreatic cancer

Pancreatic cancer (PC) remains one of the most aggressive tumors with an increasing incidence rate and reduced survival. Although surgical resection is the only potentially curative treatment for PC, only 15–20% of patients are resectable at diagnosis. To select the most appropriate treatment and thus improve outcomes, the diagnostic and therapeutic strategy for each patient with PC should be discussed within a multidisciplinary expert team. Clinical decision-making should be evidence-based, considering the staging of the tumor, the performance status and preferences of the patient. The aim of this guideline is to provide practical and evidence-based recommendations for the management of PC.

Influence of EDTA on the Electrochemical Removal of Mercury (II) in Soil from San Joaquín, Querétaro, México

<p>The removal of mercury from soil and Ca-bentonite was performed using electrochemical treatment adding ethylendiaminetetra acetic acid (EDTA) as a complexing agent to improve the electrochemical removal of Hg (II) in soil from San Joaquín, Querétaro, México. During the electrokinetic treatment in the presence of 0.1 M EDTA, most of Hg (II) migrates toward the anode obtaining the highest removal efficiencies close to 70 % in bentonite after 9 h. Using 0.1M HCl only 65 % efficiency was attained after 13 h in the cathodic side. EDTA formed a negatively charged stable complex that migrates to the cathode by the application of the electrokinetic treatment across Hg – EDTA synthesized complex.</p>

Isolation of Campylobacter spp. from Three Species of Antarctic Penguins in Different Geographic Locations

The presence of Campylobacter species was studied in three Antarctic penguin species, Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarctica) and gentoo (Pygoscelis papua). A total of 390 penguins were captured in 12 different rookeries along the Antarctic Peninsula with differences in the amount of human visitation: six colonies were highly visited [Stranger Point, King George Island (P. papua and P. adeliae); Hannah Point, Livingston Island (P. papua and P. antarctica); Deception Island (P. antarctica); and Paradise Bay, Antarctic Peninsula (P. papua)], and six colonies were rarely visited [Devil's Point, Byers Peninsula, Livingston Island (P. papua); Cierva Cove, Antarctic Peninsula (P. papua); Rongé Island (P. papua and P. antarctica); Yalour Island (P. adeliae); and Avian Island (P. adeliae)]. A total of 23 strains were isolated from penguins from nine different rookeries. Campylobacter lari subsp. lari was isolated from eight samples (seven from P. papua and one from P. adeliae); C. lari subsp. concheus from 13 (ten from P. adeliae and three from P. antarctica) and C. volucris from two samples (both from P. papua). We did not find any significant differences in the prevalence of Campylobacter spp. between the populations in highly and rarely visited areas. This is the first report of C. lari subsp. concheus and C. volucris isolation from penguins in the Antarctic region.

Measuring biological responses at different levels of organisation to assess the effects of diffuse contamination derived from harbour and industrial activities in estuarine areas

To evaluate the effects of diffuse contamination, biological measurements were applied in a scrap cargo harbour, a marina and an industrial area. Metal accumulation and biomarkers (survival in air, digestive gland and gonad histopathology, lysosomal membrane stability, intralysosomal metal accumulation, transcription of vitellogenin and MT20, peroxisome proliferation and micronuclei formation) were measured in transplanted mussels, together with metrics of benthic invertebrates. Benthic species were classified into ecological groups and univariate indexes were calculated. The marina showed high richness (16) and percentage of opportunistic species (55.1%) and low metal accumulation. Mussels in the scrap cargo harbour showed high metal accumulation, up-regulation of MT20 transcription, reduced health status (LP<6 min) and increased micronuclei frequencies (up to 11.3‰). At the industrial area, low species richness (4) and badly organised assemblages were detected and chemical analyses indicated significant amounts of bioavailable metals. Overall, selected biological measurements showed potential for the assessment of diffuse contamination.

Assessing the effects of treated and untreated urban discharges to estuarine and coastal waters applying selected biomarkers on caged mussels

To assess effects of urban discharges, biomarkers were measured in caged mussels in northern Iberian Peninsula. Lysosomal membrane stability and histopathology of gonad and digestive gland were analysed as general effect biomarkers. Exposure to specific pollutants was evaluated by autometallographical detection of metals, peroxisomal acyl-CoA oxidase activity, micronucleus test and transcription levels of vitellogenin and MT20 genes. Health status of mussels was impaired after 3 days of caging at the untreated outfall discharge and at the waste water treatment plant effluent discharge to the estuary. The most relevant finding was the significant up-regulation of vitellogenin gene transcription in male mussels exposed to the untreated outfall discharge. Metals and xenoestrogenic endocrine disruptors were bioavailable in some discharges and disturbed the health status of mussels. Biomarkers were effective in the assessment of effects of urban discharges and could be implemented in operative controls required to assess the risks associated to effluent discharges.

Liver transplanted patients with donors older than 60 years require more hospital resources

BACKGROUND

The increasing utilization of organs from older donors to fulfill the increasing demand for transplantation has been associated with an increased complication rate and shorter graft survival. Nevertheless, few studies have evaluated the impact of these donors on resource utilization. We sought to evaluate hospital resource utilization during the first year after liver transplantation among patients receiving a liver from a donor >60 years versus a younger donor.

METHODS

This prospective study evaluated 149 consecutive liver transplantations performed in our center between 2000 and 2005. We divided the patients into 2 groups according to the donor's age; group A <60 and group B, ≥ 60 years. The follow-up was for the first year. Herein we have reported data related to resource utilization, such as number and length of stay hospitalizations, length of ICU stay; surgical and diagnostic procedures including ultrasounds, cholangiography, computed tomography or magnetic resonance imaging, as well as external consultations.

RESULT

Group B patient required a greater number of hospitalizations (2.7 ± 2.4 vs 1.7 ± 1.5; P = .006), and a longer length of initial stay (37.5 ± 20.9 vs 27.8 ± 17.5 days; P = .012). There were no differences between groups concerning diagnostic and surgical procedures or external consultations.

CONCLUSION

Patients transplanted from donors >60 years required more hospital resources in the first year after transplantation.

Definitive diagnosis of neuroendocrine tumors using fine-needle aspiration-puncture guided by endoscopic ultrasonography

BACKGROUND

The detection and diagnosis of neuroendocrine tumors (NETs) is challenging. Endoscopic ultrasonography (EUS) has a significant role in the detection of NETs suspected from clinical manifestations or imaging techniques, as well as in their precise localization and cytological confirmation using EUS-Fine-needle aspiration-puncture (FNA).

OBJECTIVE

To assess the usefulness and precision of EUS-FNAP in the differential diagnosis and confirmation of NETs, in a retrospective review of our experience.

PATIENTS AND METHODS

in a total of 55 patients with suspected NETs who underwent radial or sectorial EUS, 42 tumors were detected in 40 cases. EUS-FNA using a 22G needle was performed for 16 cases with suspected functional (hormonal disorders: 6 cases) and non-functional NETs (10 cases). Ki 67 or immunocytochemistry (ICC) testing was performed for all.There was confirmation in 9 cases (5 female and 4 male) with a mean age of 51 years (range: 41-81 years).All tumors were located in the pancreas except for one in the mediastinum and one in the rectum, with a mean size of 19 mm (range: 10-40 mm).

RESULTS

There were no complications attributable to FNA. Sensitivity was 100% and both precision and PPV were 89%, as a false positive result suggested a diagnosis with NET during cytology that surgery finally revealed to be a pancreatic pseudopapillary solid tumor.

CONCLUSIONS

EUS-FNA with a 22G needle for NETs has high sensitivity and PPV at cytological confirmation with few complications.

[Encephalopathy by hyperammonemia in teenagers]

BACKGROUND

Hyperammonemia causes several alterations, mainly in the central nervous system. If hepatic failure is not its etiology, other less frequent causes must be investigated in the search for a definitive diagnosis.

CLINICAL CASE

We report the case of a 16 year old patient admitted for acute encephalopathy and hyperammonemia. After analysis, brain CT, ultrasound and abdominal Doppler, we began empirical treatment of hyperammonemia secondary to disorders of the urea cycle. We treated the brain edema and eliminated ammonia but we did not obtain favourable results and the patient died four days later.

CONCLUSIONS

The complex management of hyperammonemia and the high morbidity and mortality involved require a multidisciplinary approach. Only early treatment and identification of the hyperammonemia's etiology can avoid high morbidity and mortality in these patients.

Gastrointestinal complications in liver transplant recipients: MITOS study

INTRODUCTION

Liver transplant recipients frequently suffer gastrointestinal (GI) complications but their prevalence and their influence on quality of life remain unknown.

OBJECTIVE

The objective of this study was to asses the prevalence, impact on quality of life, and management of GI complications in liver transplant recipients.

PATIENTS AND METHODS

This was an epidemiologic, cross-sectional, multicenter study. Four hundred seventeen liver recipients were recruited in 14 centers. A questionnaire was filled for every patient.

RESULTS

The median age of the patients was 55 years. The median time since transplantation was 4.1 +/- 4 years. Whereas 19.2% presented some GI disease before transplantation, 49.4% showed this type of complication after transplantation. Diarrhea was the most prevalent GI complication, and anorexia was the GI disorder that affected patients daily activities the most frequently. GI complications were more frequent among female patients, subjects with pretransplantation hiatal hernia, and those readmitted after transplantation. Of the patients with GI complications, 70.9% received pharmacological treatment (89.7% with gastric protectors). Immunosuppressive therapy was also modified because of GI complications. Immunosuppressive drug dose was reduced in 18.1%, transiently stopped in 3.4%, and definitively stopped in 3.4% of cases. The drug most frequently changed was mycophenolate mofetil: dose reduction, 23.6%; transient withdrawal, 5.7%; and definitive withdrawal, 6.6%.

CONCLUSIONS

The prevalence of GI complications in the liver transplant population was approximately 50%. GI complications showed a significant impact on the quality of life of the patients. They were related to female gender, to pretransplantation GI pathology, and posttransplantation hospital admission. These complications were frequently managed with pharmacological therapy or with changes in immunosuppressive therapy.

Preliminary Results of Treatment With Pegylated Interferon Alpha 2A for Chronic Hepatitis C Virus in Kidney Transplant Candidates on Hemodialysis

INTRODUCTION

At present, there is little published information on the outcome of treatment with pegylated interferon (Peg-IF alpha 2a) in hepatitis C virus (HCV)-infected hemodialysis patients awaiting renal transplantation. The objective of this study was to assess the efficacy and tolerance of Peg-IF alpha 2a in this population.

PATIENTS AND METHODS

Twelve noncirrhotic HCV-infected patients (10 men, 50 +/- 8 years of age, genotype 1b 84%), were prescribed Peg-IF alpha 2a, at 135 microg/wk for 48 weeks. Liver biopsy was performed in 11 of 12 cases.

RESULTS

Six patients completed 48 weeks of treatment, with one end of treatment response (ETR), two sustained viral responses (SVRs), and three HCV relapses. Treatment was shorter in the six remaining patients: two cases 24 weeks (one due to medical reasons with relapse, one due to nonresponse), one patient chose to discontinue at 14 weeks (with relapse), one patient died of stroke at 10 weeks, and in two additional patients interferon was withdrawn at 18 weeks because of severe anemia (SVR) and at 26 weeks due to prolonged fever (relapse). Other secondary treatment-related events included anemia (requiring transfusion in two patients and major erythropoietin administration in six), and fever in four patients.

CONCLUSIONS

Peg-IF had limited efficacy in this group, with ETR in 83%, SVR in only 25%, and recurrence in 50%. Tolerance was moderate, with 4/12 (33%) discontinuing treatment due to adverse events, personal decision, or death. Large randomized controlled studies are needed to determine the role of Peg-IF treatment in this population.

Kinetics of antibodies in sera, saliva, and urine samples from adult patients with primary or secondary dengue 3 virus infections

OBJECTIVES

The kinetics of three serological markers (IgM, IgA, and IgG) in serum, saliva, and urine samples from adult patients with primary or secondary dengue infection were studied.

DESIGN

Serum, saliva, and urine samples were collected from 22 patients with clinical and confirmed dengue 3 virus infection during the outbreak in Havana City in 2001. They were tested by capture IgM (MAC-ELISA), IgA (AAC-ELISA), and IgE (EAC-ELISA) and IgG ELISA inhibition method (EIM) to detect specific dengue antibodies.

RESULTS

Similar kinetics were observed in IgM, IgA, and IgG antibodies in saliva and IgA and IgG in urine samples from secondary cases compared with kinetics in serum samples, although the values were lower. No IgG antibody was detected in saliva and urine samples in primary cases and IgM antibody was not detected in urine samples from either primary or secondary infection. All secondary cases were positive for IgG in saliva and urine samples at day 7. The kinetics of specific IgE antibodies in primary and secondary cases were different.

CONCLUSIONS

The kinetics of three serological markers (IgM, IgA, and IgG) in serum, saliva, and urine samples from adult patients with primary or secondary dengue 3 virus infection were studied for the first time, showing its behavior and usefulness in dengue virus diagnosis. The specific IgE could play a role as a serological marker in secondary infections.

TP53 status is an important prognostic marker for patients with hepatic metastases from colorectal carcinoma

10092

Background: The aim of this study was to analyze the value of TP53 gene mutations as a prognostic marker to improve the selection of patients candidates to surgery in a consecutive series of liver metastases from colorectal cancer patients. Methods: 91 patients with liver metastases from colorectal carcinoma (CRC) were included. Mutational study of TP53 gene, exons 4 to 10, was assessed both in paraffin-embedded hepatic metastasis and normal liver parenchyma by SSCP (Single Strand Chain Polymorphism) followed by sequencing of abnormal electrophoretic mobility patterns. Immunostaining of P53 and P21 proteins were assessed in the same group of patients. Results: Forty-eight out 91 (50.05%) metastases showed mutation in TP53. Higher incidence of mutations was detected in exons 5–8, although exons 9 and 10 were mutated in 28.26% of metastases. Protein-truncating mutations (nonsense and frameshift) occur in 47.8% of metastasis harboring TP53 mutations. TP53 mutation was associated with poor prognosis in univariate (P=0.0062) and multivariate Cox proportional hazard model (P=0.012) analysis. Prognosis association was maintained in the group of patients undergoing radical resection, named R0 series (n=79; P=0.008). High prevalence of TP53 mutations happen in patients with >3 metastases (65.6%; P=0.034), primary tumors Duke’s C-D stages (57.4%; 63.0%; respectively; p=0.026) and patients with age <57 years at resection. Interestingly, patients with TP53 mutations in their metastases relapsed earlier after the resection of the primary tumor (P=0.026). Postoperative 5-FU-based chemotherapy showed a better survival outcome in patients with wild-type TP53 hepatic metastases (HR: 2.92; 95% CI: 1.32–6.46; P=0.006). Conclusions: TP53 mutational status seems to be an important prognostic factor in patients with hepatic metastases from CRC.

No significant financial relationships to disclose.

Clinical and virological effects during two years of ongoing adefovir dipivoxil in the treatment of lamivudine-resistant chronic hepatitis B infection

OBJECTIVE

Our aim was to evaluate the efficacy and safety of adding adefovir to lamivudine therapy for hepatitis B virus (HBV)-infected patients resistant to Ramivudine.

PATIENTS AND METHODS

Among 17 studied patients, 7 had chronic active HBV infection and 10 were posttransplant with HBV infection (9 with de novo HBV). They received lamivudine plus adefovir therapy for 2 years. We assessed reductions in serum HBV-DNA and alanine aminotransferase (ALT) levels, loss of HBeAg (in HBeAg+ cases), and HBsAg clearance.

RESULTS

A virological response, as defined by HBV-DNA below the cut off by hybridization, was observed in 12 (70.6%) patients and loss of HBeAg in 4 (44.4%) of the 9 initially HBeAg-positive cases. A biochemical response, defined as a decreased serum ALT to the normal range, occurred in 4 (26.7%) patients. Median serum creatinine increased in 3 of 15 (20%) patients, excluding those on hemodialysis. There were two noteworthy cases of sustained HBsAg seroconversion with adefovir (11.8%): one patient with de novo HBV infection posttransplantation and positive hepatitis C virus-RNA serology, and one patient with decompensated HBV cirrhosis in whom viral replication ceased, making him eligible for transplantation.

CONCLUSIONS

Currently, adefovir is an effective rescue therapy that broadens the existing range of options for patients with lamivudine-resistant chronic hepatitis B infection, particularly those with decompensated cirrhosis awaiting a liver graft, and those with recurrent posttransplantation HBV. The relatively small biochemical response seen in these patients may be attributable to the high prevalence of concomitant hepatitis C virus infection (41%).

Serological markers during dengue 3 primary and secondary infections

BACKGROUND

The detection of the IgM antibody for the dengue virus in serum by ELISA has become one of the most important and useful methods for diagnosis of dengue using a single acute-phase serum sample. Currently, this system is an invaluable tool for the surveillance of dengue fever (DF) and dengue hemorrhagic fever (DHF). The usefulness of other serological markers such as IgA and IgE have been less studied.

OBJECTIVE

To study the IgM, IgA and IgE specific antibody response in dengue 3 infected patients with different clinical picture and type of infection.

STUDY DESIGN

One hundred and twenty-seven serum samples collected on days 5-7 at the onset of fever from clinically and serologically confirmed dengue cases were studied. Forty-two were classified as primary dengue fever cases, 48 as secondary dengue fever cases and 37 as secondary dengue hemorrhagic fever cases. All samples were tested by capture ELISA in order to detect dengue IgM, IgA and IgE antibodies.

RESULTS AND CONCLUSIONS

In this study, significant differences were observed in the IgM, IgA and IgE response between the study groups. High IgA and IgE OD ratios in secondary dengue cases were found. The usefulness of serotype specific IgM antibody detection is also analyzed and discussed. A priority for future dengue research in terms of protection, recovery of infection and immunopathogenesis is to elucidate the role of these immunoglobulins. The cross reactivity response to IgM between dengue virus serotypes in primary and secondary cases should also be more studied.

Risk factors for development of de novo neoplasia after liver transplantation

Liver transplant recipients are at greater risk for de novo neoplasia, especially lymphoma and nonmelanoma skin cancer; however, risk factors for this complication have not been well studied. Clinical and pathological records of 137 consecutive liver transplant recipients who had survived for at least 1 year were reviewed to register de novo neoplasia. Ten variables were analyzed for their association with the development of de novo malignancies by means of a log-rank test and stepwise selection in a multivariate analysis using the Cox proportional hazard model. Thirty de novo neoplasias appeared in 22 of 137 transplant recipients between 12 and 104 months after orthotopic liver transplantation (OLT; median follow-up, 69 months): 14 patients had 21 skin cancers, 6 patients had solid-organ cancer, and 3 patients developed a lymphoproliferative disease. Probabilities of de novo neoplasia were 13% at 5 years post-OLT and 26% at 8 years post-OLT. The only associated risk factor for any neoplasia was age. Age and hepatocarcinoma were independent risk factors associated with skin cancer. That hepatocarcinoma in the explanted liver is an independent risk factor for skin cancer suggests there is individual susceptibility to both neoplasias.

Safety and preliminary immunogenicity of the recombinant outer membrane protein P64k of Neisseria meningitidis in human volunteers

P64k is a meningococcal protein from Neisseria meningitidis that has been obtained by recombinant DNA technology. Recombinant P64k has been extensively characterized by physicochemical and immunological methods. Lately this protein has been found to act as a versatile immunological carrier for weak antigens in mice. In the present work, a Phase I clinical trial was carried out in healthy volunteers who received three inoculations of either placebo or recombinant P64k (20 or 50 microg). No severe adverse events occurred during the trial. Only mild adverse events in ten volunteers were observed. At 1 month after the third dose, 15 out of 18 volunteers (83.3%) who received the recombinant antigen had a P64k-specific antibody titre > or =1:100, as detected by ELISA. A fourth dose, given 9 months after the third one, elicited a potent booster immune response in P64k vaccinees. Accordingly, these P64k formulations were considered safe and immunogenic in healthy human volunteers.

[Changes in nerve growth factor levels related to age and neurotrophic treatment in non-human primate]

INTRODUCTION

To examine the amounts and role of growth factors in different tissues and corporal fluid, new sensitive techniques have to be developed. A major problem is that the normal concentration of trophic substances, such as nerve growth factor (NGF), in central and peripheral nervous system and in fluids is very low (ng pg/ml). A valuable method of research is the sensitive two site enzyme immunoassay using the monoclonal antibody 27/21 to mouse NGF. Materials and methods. The present work applied this enzyme immunoassay to examine the NGF levels in normal non human primate sera (n= 94) and applied this assay to study of NGF levels in two non human primate receiving NGF infusion: one young and one aged. Two groups of non human primate sera were studied one young adult (n= 69) and one aged (n= 25). The serum samples NGF treated non human primate were taken before the infusion and at the 1st week and 1st, 3rd, 6th and 12th month after infusion.

RESULTS

To further test the specificity of conjugate binding, dilutions of the non human primate sera were preincubated with an excess of monoclonal NGF antibody 27/21 in solution. With this strategy it was possible to completely block the signal obtained using the enzyme immunoassay. We found very low levels of NGF in aged monkeys (0.054 ng/ml) when compared with young adult group (0.152 ng/ml) (p> 0.01). The NGF levels in aged non human primate treatment with NGF was very low before (0.50 ng/ml) and during NGF treatment evolution time, whereas at the the 12th month showed an increase in NGF levels (0.180 ng/ml). We found normal values of NGF in the young monkey before and during the first year after NGF infusion.

CONCLUSIONS

Using the enzyme immunoassay described it is possible to know the serum concentration of NGF immunoreactive in non human primate and this assay is able to detect peripheral changes in NGF levels after intracerebral infusion of NGF.

A phase I clinical trial of a multi-epitope polypeptide TAB9 combined with Montanide ISA 720 adjuvant in non-HIV-1 infected human volunteers

A phase I clinical trial was performed to examine the safety and immunogenicity of a multi-epitope polypeptide comprising the central 15 amino acids of the V3 loop from six HIV-1 isolates. This protein called TAB9 was emulsified in Montanide ISA720 (Seppic, Paris) and administered intramuscularly at doses of 0, 0.2 and 1 mg to 24 healthy, HIV-1 seronegative adult males. Three immunisations were given at months 0, 1 and 6 in a randomised, double blind, placebo controlled clinical trial. The placebo was generally well tolerated. However, severe local reactions were observed in TAB9 vaccinated subjects after the second and third inoculations. Seven out of eight volunteers from the lower dose group showed moderate or severe local inflammation, while four out of eight subjects from the higher dose group developed granulomas and sterile abscesses. In general, the reactogenicity depended on the number of inoculations given and the dose of TAB9. Both doses were immunogenic, all immunised volunteers seroconverted and antibodies were broadly reactive against the V3 peptides included in the protein. All vaccine's sera reacted against gp120 in Western blot and 50% of them also neutralised at least one out of five laboratory isolates tested. No differences between doses were found. Anti TAB9 lymphoproliferative responses were observed, being more intense in the high dose group. Due to the strong local reactions that were found in this study, a change in the formulation will be required for further trials with this vaccine candidate in humans.

Postreperfusion biopsies are useful in predicting complications after liver transplantation

Biliary complications after orthotopic liver transplantation (OLT) may occur because of preservation injury (PI). In this study, we examine findings on routine reperfusion biopsy specimens in relation to the occurrence of biliary complications and graft outcome. From 1997 to 2000, a total of 193 OLTs were performed in our center. Postreperfusion biopsy specimens were analyzed and histological lesions were graded. For analysis, grafts were grouped into 2 categories: the presence or absence of PI (severe to moderate lesions versus mild or no lesions). Histological evidence of PI was present in 17% of the biopsy specimens. The incidence of grafts with PI and ischemia time longer than 12 hours was 38% compared with 14% in PI and short ischemia time (P =.02). Biliary complications were also more frequent in the PI group (28% v 14%; P =.03). Study of risk factors by means of logistic regression analysis confirmed that the PI group had a greater risk for biliary complications (relative risk, 2.8; 95% confidence interval, 1 to 7.4; P =.03). Moreover, moderate macrovesicular steatosis was found in 6% of the grafts, resulting in a 40% graft loss rate. We found that an increased presence of neutrophilic infiltrates in the postreperfusion biopsy specimen, indicating PI, was related to an increased incidence of biliary complications. Moreover, moderate macrovesicular steatosis was associated with increased graft loss. Therefore, postreperfusion biopsies are useful in anticipating post-OLT complications.

Heart and liver xenotransplantation under low-dose tacrolimus: graft survival after withdrawal of immunosuppression

BACKGROUND

The hamster-to-rat xenotransplantation model is a useful model to investigate the features of extended host response to long-surviving xenografts. Early xenoantibody responses are T-cell independent and resistant to tacrolimus. Treatment with the combination of mofetil mycophenolate plus FK506 avoids acute xenograft rejection completely, but after withdrawal of immunosuppression hamster grafts are rejected by a process called late xenograft rejection (LXR).

METHODS

Hamster hearts and livers were transplanted into Lewis rats. Grafted rats were treated with mofetil mycophenolate (25 mg/kg/day) for 8 days and FK506 (0.2 mg/kg/day) for 31 days. Serum IgM and IgG levels were determined by flow cytometry and interferon-gamma levels by ELISA. IgM, IgG, and C3 deposits were measured in tissue by immunofluorescence, and leukocyte infiltration was measured by immunoperoxidase staining. Results. Survival of heart and liver xenografts in the rats was 48+/-4 days and 63+/-8 days, respectively. After cessation of all immunosuppression, hearts were rejected in 18+/-4 days and livers in 33+/-8 days. Production sequences of xenoantibodies in the two organs differed substantially, especially 7 days after transplantation and at the moment of rejection. Quantification of interferon-gamma levels indicated that there were no significant changes after transplantation. Histological and immunohistochemical studies showed signs of humoral mechanism of LXR in rats undergoing heart transplantation and cellular mechanism of LXR in those that received a liver transplant. Conclusions. These observations suggest that rejection in the hamster-to-rat heart xenotransplantation model is mediated by a T cell-independent B-cell response to which a T cell-dependent B-cell response is added in LXR. In the liver xenotransplantation model, our hypothesis is that LXR is mediated by a mixed cell mechanism, involving lymphocytes CD4+ CD45RC+, macrophages, and cytotoxic T lymphocytes. In summary, we have demonstrated and compared the peculiar features of LXR in two different organs.

Influence of donor post-reperfusion changes on graft evolution after liver transplant

INTRODUCTION

The increase in indications for liver transplantation has meant that waiting lists are growing ever longer. For this reason, broadening the donor pool is a priority for most groups.

OBJECTIVE

The objective of this study was to analyze the predictive value of post-reperfusion biopsy in the evolution of graft function after liver transplantation.

PATIENTS

One hundred and forty-eight liver biopsies, obtained after graft reperfusion, were analyzed. Eight pathological variables and thirty-seven clinical variables of the donors were recorded. Risk factors for presenting primary graft non-function or dysfunction were studied with logistic regression models. Factors associated to the long-term graft failure were studied using Cox analysis and actuarial survival curves.

RESULTS

Microvesicular steatosis greater than 50% was the only risk factor associated to graft dysfunction in the multivariate logistic regression model. Microvesicular steatosis greater than 30%, severe hepatocyte necrosis and presence of abundant neutrophilic leukocytes were risk factors associated to graft failure in the univariate study. Only steatosis remained as an independent risk factor in the multivariate study. These grafts also presented poorer long-term survival. Abundant polymorphonuclear infiltrate was associated to a higher frequency of biliary complications.

CONCLUSIONS

Microvesicular steatosis implies a better evolution than macrovesicular steatosis. Neutrophilic infiltrate and hepatocellular necrosis lead to poorer initial graft function and reduced long-term survival.

Hepatic metastases from colorectal cancer: preoperative detection and assessment of resectability with helical CT

PURPOSE

To prospectively evaluate helical computed tomography (CT) in the preoperative detection of hepatic metastases and assessment of resectability with surgical, intraoperative ultrasonographic (US), and histopathologic correlation.

MATERIALS AND METHODS

Between October 1995 and December 1998, preoperative staging with helical CT (5-mm collimation; reconstruction interval, 5 mm) was performed in 157 patients with hepatic metastases. Iodinated contrast material was injected intravenously (160-170 mL; rate, 2.5-3.0 mL/sec); acquisition began at 60-70 seconds. Four radiologists prospectively assessed the metastatic involvement of the liver by indicating the number and location of the lesions; resection was indicated in 113 patients (119 instances). Helical CT findings were correlated with pathologic and surgical findings on a lesion-by-lesion basis.

RESULTS

Intraoperative US, palpation, and histopathologic examination revealed 290 liver metastases; helical CT correctly depicted 247. Helical CT results were the following: overall detection rate, 85.1% (95% CI: 80.8%, 89.3%); positive predictive value, 96.1% (95% CI: 92.9%, 98.1%); and false-positive rate, 3.9% (10 of 257 findings; 95% CI: 1.9%, 7.1%). False-positive findings were related to hemangioendothelioma, hemangioma, hepatic peliosis, biliary adenoma, centrilobar hemorrhage, biliary hamartoma, periportal fibrosis, and normal liver parenchyma. Curative resection was performed in 112 instances with a resectability rate of 94.1%. Four-year patient survival rate was 58.6%.

CONCLUSION

Helical CT is a noninvasive, reliable, and accurate technique for imaging the liver and should be considered as the standard preoperative work-up of hepatic metastases from colorectal cancer.

Changing strategies in diagnosis and management of hilar cholangiocarcinoma

Hilar cholangiocarcinoma is one of the most difficult tumors to stage and treat. This study aims to evaluate (1) the best diagnostic imaging, (2) the usefulness of preoperative biliary drainage, (3) the resectability rate, and (4) the results of palliative treatments and surgical resection. Seventy-six patients with hilar cholangiocarcinoma with a mean age of 64 +/- 11 years were treated at our institution from 1989 to 1999. Patients were studied preoperatively using ultrasound, computed tomography (CT), and percutaneous cholangiography or magnetic resonance cholangiography. Forty-eight patients (63%) underwent palliative treatment. Twenty-eight patients underwent surgical curative therapy; 20 resections and 8 orthotopic liver transplantations (OLTs). Percutaneous transhepatic cholangiography was performed in 18 of 28 patients (64%), and magnetic resonance cholangiography in 5 patients; both methods were equally effective in establishing tumoral invasion of the biliary ducts. Five patients did not undergo either diagnostic modality. Excluding the patients who underwent OLT, no significant differences were found in surgical mortality (1 v 2 patients) or postoperative morbidity (100% v 66%) for patients with and without preoperative biliary drainage. The postoperative mortality rate was 11% (3 of 28 patients). The overall resectability rate was 37%. Mean survival in the surgical and palliative groups was 35 and 6 months, respectively (P <.0001). Patients who underwent OLT had a better 5-year survival rate than those treated by tumor resection (36% v 21%; P =.02). Combined chemotherapy and radiotherapy apparently did not provide a significant survival benefit. Helical CT and magnetic resonance cholangiography are useful techniques to delineate tumor extent and rule out vascular invasion and lymph node or liver metastases. No clear conclusions regarding preoperative drainage can be drawn from this study. A high resectability rate (37%) is feasible with major hepatectomy.

[Analysis of 500 liver transplantations at Bellvitge Hospital, Spain]

BACKGROUND

We present the experience of the liver transplantation program at the Hospital of Bellvitge with 500 transplantations performed during 15 years, to describe changes in liver transplantation observed throughout the time and to analyze the long term results.

PATIENTS AND METHOD

Five groups each one including 100 consecutive transplantations are studied.

RESULTS

The main indications were hepatocellular carcinoma (23%), alcoholic cirrhosis (22.8%), and post-hepatitis C cirrhosis (18.8%). Sixty-five retransplantations were performed in 59 patients (13%), being the more frequent indications arterial thrombosis (13 patients) and primary nonfunction of graft (10 patients). In 10 patients a hepatorenal transplantation was performed. In group I, the most frequent donor cause of death was cranial traumatism (80%), while in group V it was the vascular pathology (52%). There were other significative differences between these groups of patients (I vs V): patients with stage 2 or 3 from UNOS status (45 vs 19%), blood use (29.6 [26] vs 4.6 [5.3] PRBC), ICU stay (13 [13] vs 7.4 [11] days), hospital stay (40 [52] vs 23.7 [17] days), rejection rate (46 vs 20%) and primary graft nonfunction (9 vs 3%). However, the infection rates (48 vs 54.5%) and biliary tract complications (26 vs 20%) have not shown statistically significant differences. Actuarial one and 5-year survival are 83 and 70% respectively.

CONCLUSIONS

An important and progressive improvement of liver transplantation results has been observed. However, de novo tumours, hepatitis C virus recurrence and chronic rejection can limit long term results.

Intrahepatic peripheral cholangiocarcinoma: CT evaluation

BACKGROUND

The purpose of our study was to evaluate the imaging features and patterns of contrast enhancement in peripheral cholangiocarcinomas with computed tomography (CT) and correlate these features with histologic findings when available.

METHODS

We reviewed the CT scans of 24 patients with 25 peripheral cholangiocarcinomas proved by orthotopic liver transplantation (n = 1), liver resection (n = 7), percutaneous needle biopsy (n = 10), and fine needle aspiration biopsy (n = 6). Incremental dynamic nonhelical CT was performed in four cases and helical CT in 21 cases. Portal venous phase images were obtained in all 25 cases. Fourteen patients underwent helical CT during arterial and portal phases. Delayed images were obtained in 20 patients.

RESULTS

The size of the tumors ranged from 1.2 to 17 cm. Bile duct dilatation was present in 13 patients (52%), and regional lymph node enlargement was observed in six patients (24%). Retraction of the liver capsule was present in nine patients (36%). In eight patients (32%), satellite nodules were also detected. All tumors were globally hypodense during the portal phase. In 14 patients (70%), delayed images disclosed hyperattenuating tumors. Rimlike contrast enhancement was the most frequent pattern observed in either arterial (57% of patients) or portal (60% of patients) phase imaging. Portal venous encasement was seen in 10 patients (40%).

CONCLUSION

In the proper clinical setting, detection of a hypodense hepatic lesion with peripheral enhancement, biliary dilatation, and contrast enhancement on delayed images are highly suggestive of peripheral intrahepatic cholangiocarcinoma.

Resection or transplantation for hepatocellular carcinoma in cirrhotic patients: outcomes based on indicated treatment strategy

BACKGROUND

Surgical resection has been the treatment of choice for hepatocellular carcinoma (HCC), but the resection rate remains low in cirrhotic patients and recurrence is common. Unfavorable results compared with benign disease and the shortage of organ donors have led to a restricted indication for orthotopic liver transplantation (OLT) for HCC.

STUDY DESIGN

The aim of this study was to analyze the results of our surgical approach to HCC in patients with cirrhosis. The first treatment strategy indicated in these patients was OLT. From January 1990 to May 1999, 85 patients underwent OLT and the remaining 35 had surgical resection.

RESULTS

One-, 3-, and 5-year survival rates were 84%, 74%, and 60% versus 83%, 57%, and 51%, respectively, in the OLT and resection groups (p = 0.34). Hepatic tumor recurrence was much less frequent in the OLT group than in the resection group. The 1-, 3-, and 5-year disease-free survival rates were 83%, 72%, and 60% versus 70%, 44%, and 31%, respectively (p = 0.027). In the multivariate Cox regression analysis, macroscopic vascular invasion was the only factor independently associated with death or recurrence after OLT (p = 0.006). After partial liver resection, the tumors significantly associated with mortality and recurrence in the multivariate analysis were solitary or multiple tumors greater than 2cm with microscopic vascular invasion (pathologic pT3) (p = 0.01).

CONCLUSIONS

Our results confirm that in cirrhotic patients, OLT may provide better outcomes than liver resection in carefully selected HCC and that longterm survival is similar to the results of OLT in cirrhotic patients without tumors.

Liver xenotransplantation: changes in lipid and lipoprotein concentration after long-term graft survival

BACKGROUND/AIMS

Today, scientists devote considerable effort to the study of mechanisms of xenograft rejection, but with liver xenotransplantation (XTx) researchers face the added problem of metabolic incompatibility between species. To date, there have been few studies of molecular xenogeneic interactions, perhaps because little progress has been made in solving immunological problems. This study is an initial analysis of lipoprotein metabolism in a hamster-to-rat hepatic xenotransplantation model.

METHODS

There were 6 experimental groups (n=8): (1) male Sprague-Dawley (S.D.) rats (220-280 g); (2) male Golden Syrian hamsters (100-150 g); (3) S.D. rats, "sham" operation with immunosuppression; (4) S.D. rat-to-S.D. rat alloTx; (5) S.D. rat-to-S.D. rat alloTx with immunosuppression; (6) XTx hamster G.S-to-S.D. rat with immunosuppression. Mofetil mycophenolate (25 mg/kg/d) was administered for 14 days and FK506 (0.2 mg/kg/d) for 45 days (groups 3, 5 and 6). After 24 h fasting, animals were sacrificed (day +50 postransplantation) and a complete lipoprotein profile was determined. Serum lipoproteins were subfractioned by ultracentrifugation in density gradient.

RESULTS

There was a large increase in serum lipid levels in xenografted rats compared with control rats and allografted rats. Xenografted rats presented a severely altered lipoprotein profile compared with normal rats. Surprisingly, the characterisation of lipoproteins in xenografted rats displayed the same composition as donor animals. Histological study did not show signs of alteration of the hepatic architecture.

CONCLUSIONS

Since the liver is the main solid organ co-ordinator of metabolic pathways, such as lipid metabolism, hepatic xenotransplantation makes changes in lipid concentrations in the recipient and also changes in lipid compositions of lipoproteins. Hepatic xenotransplantation is not a feasible solution given the organ's metabolic complexity.