Serum antibody response against Helicobacter pylori NCTC 11637 smooth- and rough-lipopolysaccharide phenotypes in patients with H. pylori-related gastropathy

The antigenicity of the Helicobacter pylori lipopolysaccharide (LPS) molecule during the course of natural H. pylori infection in humans was investigated. The IgG and IgA responses against smooth (S)- and rough (R)-form LPS were evaluated in H. pylori positive patients with chronic gastritis (CG, n = 30) and duodenal ulcer disease (DU, n = 16), and in 15 H. pylori-negative dyspeptic subjects. The results demonstrated that anti H. pylori LPS IgG and IgA antibody levels were significantly enhanced in both groups of H. pylori-positive patients compared with H. pylori-negative subjects, thus confirming that H. pylori LPS is part of the immunogenic antigen profile of the bacterium. In addition, a marked response against R-LPS, which significantly correlated with that observed against S-LPS, was found for both IgG and IgA, thus indicating that core oligosaccharide plays a powerful immunogenic role. Since the O-side chain of LPS from H. pylori NCTC 11637 contains epitopes which mimic Lewis x (Lex) antigens, the presence of antibodies to monomeric, trimeric, and polymeric Lex was also investigated. Antibodies against polymeric Lex were detected in two patients suffering from chronic atrophic gastritis and active chronic gastritis, respectively.

A Bayesian methodology to improve prediction of early graft loss after liver transplantation derived from the liver match study

BACKGROUND

To generate a robust predictive model of Early (3 months) Graft Loss after liver transplantation, we used a Bayesian approach to combine evidence from a prospective European cohort (Liver-Match) and the United Network for Organ Sharing registry.

METHODS

Liver-Match included 1480 consecutive primary liver transplants performed from 2007 to 2009 and the United Network for Organ Sharing a time-matched series of 9740 transplants. There were 173 and 706 Early Graft Loss, respectively. Multivariate analysis identified as significant predictors of Early Graft Loss: donor age, donation after cardiac death, cold ischaemia time, donor body mass index and height, recipient creatinine, bilirubin, disease aetiology, prior upper abdominal surgery and portal thrombosis.

RESULTS

A Bayesian Cox model was fitted to Liver-Match data using the United Network for Organ Sharing findings as prior information, allowing to generate an Early Graft Loss-Donor Risk Index and an Early Graft Loss-Recipient Risk Index. A Donor-Recipient Allocation Model, obtained by adding Early Graft Loss-Donor Risk Index to Early Graft Loss-Recipient Risk Index, was then validated in a distinct United Network for Organ Sharing (year 2010) cohort including 2964 transplants. Donor-Recipient Allocation Model updating using the independent Turin Transplant Centre dataset, allowed to predict Early Graft Loss with good accuracy (c-statistic: 0.76).

CONCLUSION

Donor-Recipient Allocation Model allows a reliable donor and recipient-based Early Graft Loss prediction. The Bayesian approach permits to adapt the original Donor-Recipient Allocation Model by incorporating evidence from other cohorts, resulting in significantly improved predictive capability.

Conversion from twice-daily to once-daily Tacrolimus administration in liver transplant patient: results of long term follow-up

OBJECTIVES

The aim of this study was to assess the long term effects of once-daily tacrolimus (OD-TAC) in a cohort of stable liver recipients converted from the twice daily tacrolimus (TD TAC), with a particular attention on the possible effects on renal function.

PATIENTS AND METHODS

Between September 2008 and September 2010 conversion from TD-TAC to OD-TAC was proposed in adult stable liver transplant recipients who were followed as outpatients in our Transplant centre. Conversion from TC-TAC to OD-TAC was based on a 1 mg: 1 mg proportion. Tacrolimus through levels, laboratory parameters, metabolic disorders and any adverse events were evaluated at 1, 3, 6, 12 and 24 months after conversion. Renal function was evaluated using creatinine plasma levels and estimated glomerular filtration rate (GFR) derived from the Modification of Diet in Renal Disease (MDRD). Analysis of variance and t test for paired data were utilised for the comparison of the results obtained at the scheduled controls.

RESULTS

Sixty-five patients were enrolled in the study (50 males, 15 females, mean age 59±8 years). Median time since liver transplant (LT) was 39 months (range: 6 to 83 months). All patients were followed for a minimum of 12 months. Ninety per cent of patients stabilized their blood levels within 45 days. Liver function, glucose and plasma lipids concentration and arterial blood pressure remained stable during the study. Renal function improved during the 24 months of follow-up. No adverse events or acute rejection episodes were recorded during the study.

CONCLUSIONS

Considering the advantage on patient compliance, the equivalent efficacy and the adequate safety of OD-TAC formulation may represent a useful option in liver transplant patients, with a possible advantage on renal function.

Bone disorders in patients with chronic liver disease awaiting liver transplantation

BACKGROUND

An important complication of chronic liver disease is osteodystrophy, which includes osteoporosis and the much rarer osteomalacia. Both conditions are associated with significant morbidity through fractures resulting in pain, deformity, and immobility. Liver transplantation may further deteriorate bone metabolism. The aim of the present study was to investigate the frequency and severity of hepatic osteodystrophy among patients with liver cirrhosis who were referred for liver transplantation. We also evaluated modifications in bone metabolism after liver transplantation.

MATERIALS AND METHODS

We recruited 35 consecutive patients with chronic liver disease who were undergoing assessment for transplantation over a 1-year period. Bone mass in the total skeleton and proximal hip was evaluated using a dual-energy X-ray absorptiometry device (Lunar Prodigy Advance, GE Healthcare, USA). According to World Health Organization recommendations, osteoporosis was defined as a T score < -2.5 and osteopenia as T score between -1 and -2.5.

RESULTS

We enrolled in the study 35 patients, including 8 females and 27 males of overall mean age of 57 +/- 7, who showed a viral etiology (57%) or alcohol etiology (28%), Child-Pugh 8.7 +/- 2.3. The overall prevalence of osteodystrophy was 40% (26% osteopenia and 14% osteoporosis). No difference was evident according to gender, severity of liver disease (Child-Pugh, Model for End-stage Liver Disease), or origin of liver disease. A subgroup of 10 transplanted patients reached 3-month follow-up, showing total body T score with a significant decrease after 3 months while femoral T scores tended to decrease insignificantly.

CONCLUSIONS

This study revealed a high prevalence of low bone mineral density among cirrhotic patients before liver transplantation. We suggest that both bone mineral density and biochemical examinations should be considered to be routine tests to identify the status of bone mass and bone metabolism among recipients prior to liver transplantation.

Alloantibodies and outcomes of deceased donor kidney allografts

Analysis of the anti-HLA antibody status of 100 recipients of kidneys from deceased donors demonstrated that presensitization and the development of alloantibodies after transplantation are associated with the development of antibody mediated as well as cellular rejection. This finding indicates that the humoral arm of the immune response is also involved in cell-mediated rejection and/or that there may be a continuum between these two forms of rejection. Most episodes of rejection were successfully reversed in our population, as shown by the overall 3-year actuarial survival of 98% in nonsensitized and 91% in sensitized recipients, emphasizing the importance of comprehensive antibody studies.

Preliminary Evaluation of the New TACR Flex Method Versus MEIA Method in the Therapeutic Monitoring of Tacrolimus in Organ Transplantation

Tacrolimus (FK506) is an effective macrolide immunosuppressant widely used to prevent organ rejection following transplantation. Monitoring blood levels of tacrolimus is essential to assess organ rejection versus toxicity, because of the narrow therapeutic range and pharmacokinetic variability. The increased request for therapeutic drug monitoring is an interesting challenge for clinical laboratories. The automated immunoassay methods provide correct results and a turnaround time considerably reduced compared to HPLC and HPLC-MS which remain the gold standard for accuracy and economical advantages. A new immunoassay method, TACR Flex Dimension, is a commercially available, automated pretreatment test. The purpose of this study was to compare two analytical methods: the MEIA II tacrolimus immunoassay using the IMx analyzer and the new TACR Flex tacrolimus immunoassay on the Dimension system. Tacrolimus results obtained using the two methods were compared using European control and 93 whole blood samples from kidney and liver transplant patients. The tacrolimus concentrations measured by Flex Dimension for all samples were higher (0.7 to 16.1 ng/mL) than results obtained with MEIA (0.2 to 13.4 ng/mL), a mean difference expressed in percentage of 31.7%, and a correlation coefficient of 0.85. The data obtained by both methods using three European controls showed similar concentrations. The TACR Flex Dimension method provided a higher automation level and therefore a lower incidence of preanalytical errors and a lower turnaround time.

Fertility Following Solid Organ Transplantation

Fertility is usually restored in women after solid organ transplantation, and successful pregnancies have been reported in female recipients of kidney, liver, heart, pancreas-liver, and lung transplants. However, women with solid organ allografts have higher incidence of pregnancy complications like hypertension, preeclampsia, preterm delivery. Hypertension appears to be dependent on the type of immunosuppressive agents. The influence of pregnancy on the risk of rejection is poorly known on the basis of available data. Rejection rate appears to be at least similar to the nonpregnant population. In some cases, such as in liver transplant pregnant women, even higher as compared to the nonpregnant population. Maintaining appropriate blood levels of immunosuppressive drugs is currently recommended. Malformation rate in the offsprings of transplanted women appears to not be increased; long-term follow- up of children born to allograft recipients is necessary to investigate possible developmental, immunological, or oncological disorders. We followed 70 pregnancies after kidney transplantation and nine after liver transplantation. All recipients were maintained on immunosuppressive therapy during pregnancy, except one mother who refused immunosuppression and experienced transplant rejection. Hypertension was the most frequent complication during pregnancy: in 23% of kidney transplantated mothers and in one out of nine liver transplant recipients. The only malformation observed in the newborns was the dislocation of the hip in the child of a kidney transplant recipient.

Giant hemangiomas of the liver: surgical strategies and technical aspects

The incidence of hemangiomas is 2-7% in the general population. We evaluated more than 300 patients with hepatic hemangiomas. Surgical removal of hepatic hemangiomas was performed in 48 cases due to uncertain diagnosis (2 cases), intractable symptoms (26 cases), size increase (18 cases), and liver failure in 2 cases that were treated by hepatic transplantation. In all, 26 patients underwent enucleation of hemangiomas or segmentectomies, while the remaining 20 patients underwent right lobectomies or left lateral segmentectomies. Blood transfusions were required in four cases (including two liver transplants); mean post-resection hospital stay was 6.3 days. We observed no perioperative mortality and only two cases of major morbidity (bile leaks not requiring reoperation). Our experience confirms that, after adequate patient selection, surgical treatment of hepatic hemangiomas is a very effective therapeutic choice with no mortality and low morbidity.

Changes in coagulation-fibrinolysis balance in blood mononuclear cells and in gastric mucosa from patients with Helicobacter pylori infection

INTRODUCTION

Helicobacter pylori and some of its virulence factors stimulate human blood mononuclear cells (MNC) in vitro to produce tissue factor (TF) and plasminogen activator inhibitor-2 (PAI-2). In this study we investigated the procoagulant-fibrinolytic potential of blood MNC in patients with H. pylori infection. In the same patients we also evaluated the coagulation-fibrinolysis profile in gastric tissue and in plasma.

METHODS AND RESULTS

The production of TF and PAI-2 was evaluated in 61 patients with dyspepsia, 31 positive and 30 negative for H. pylori infection. TF expressed by MNC and PAI-2 accumulation in cell culture medium after incubation for 20 h at 37 degrees C were significantly higher in H. pylori(+) than in H. pylori(-) patients and were significantly correlated. TF and PAI-2 content in extracts of gastric mucosa was similar in the two groups whereas lower levels of tissue plasminogen activator (t-PA) and thrombomodulin (TM) antigens were found in the antrum of H. pylori(+) patients. No difference between the groups was observed in plasma thrombus precursor protein, prothrombin fragment 1+2, D-dimer, t-PA, PAI-1, TM and thrombin activatable fibrinolysis inhibitor.

CONCLUSIONS

H. pylori infection is associated with functional abnormalities of blood MNC resulting in the coordinate expression of TF and antifibrinolytic activity. Changes in cell coagulation-fibrinolysis balance may represent a link between H. pylori infection and ischemic heart disease.

Predictive Factors of Outcome After Liver Transplantation in Patients With Cirrhosis and Hepatocellular Carcinoma

Studies to define the optimal upper limits of tumor size and number as predictors of outcome after orthotopic liver transplantation (OLT) have yielded conflicting results. We analyzed 72 patients with cirrhosis and hepatocellular carcinoma (HCC) who underwent OLT over a 12-year period in a single center. Predictive factors for survival and tumor recurrence, according to the Milan criteria, were also examined. Our cohort included 60 men and 12 women of mean age 54 +/- 8 years and mean follow-up of 40 +/- 39 months. Origin of cirrhosis was postviral in 70% and Child class B or C in two thirds of patients. HCC was multifocal in 61%; about one fifth of patients had micro- or macrovascular involvement or positive nodes upon histologic examination. The cumulative size of the lesions was <3 cm in 17 patients; >3 to < or =5 cm in 28 patients; >5 to < or =8 cm in 14 patients; and >8 cm in 13 patients. According to the number and size of tumor nodules, 49 patients met the Milan criteria. During follow-up 25 patients died, 13 due to tumor recurrence. The 1- and 2-year survivals were 90% and 85% for patients who met the Milan criteria versus 57% and 51% for patients exceeding those limits (P = .006). A cumulative tumor size >8 cm was predictive of survival and tumor recurrence upon multivariate analysis. The adoption of Milan criteria for selection of cirrhotic patients has improved survival and reduced the rate of tumor recurrence. The evaluation of cumulative tumor size might further improve patient selection.

Alpha-SMA expression in hepatic stellate cells and quantitative analysis of hepatic fibrosis in cirrhosis and in recurrent chronic hepatitis after liver transplantation

BACKGROUND

The alpha isotype of actin expressed by hepatic stellate cells reflects their activation to myofibroblast-like cell and has been directly related to experimental liver fibrogenesis, and indirectly to human fibrosis in chronic liver disease.

AIMS

To evaluate the changes in distribution and percentage of alpha-smooth muscle actin-positive hepatic stellate cells and the correlation with the degree of the fibrosis in cirrhotic livers, as well as in patients with recurrent HCV chronic hepatitis after liver transplantation.

METHODS

Human liver biopsies were divided in four groups: (1) normal livers obtained from cadaveric liver donors (n=35), (2) cirrhosis post-HBV hepatitis (n=11), (3) cirrhosis post-HCV hepatitis (n=10), and (4) post-transplant recurrent HCV chronic hepatitis (n=13). Samples were stained with anti-alpha-smooth muscle actin antibody by immunoperoxidase method and semi-quantitatively evaluated. Liver fibrosis was assessed from specimens stained with Masson's trichrome and quantified by computer image analysis.

RESULTS

The percentage of alpha-smooth muscle actin-positive hepatic stellate cells was significantly higher in the HBV cirrhosis, HCV cirrhosis and post-transplant HCV recurrent hepatitis groups (36.1+/-15.2, 23.8+/-19.7 and 27.8+/-16.4%, respectively) compared to the liver donor group (2.9+/-4.0%). The alpha-smooth muscle actin-positive hepatic stellate cells to fibrous tissue ratio were significantly higher in the post-transplant recurrent HCV hepatitis group (2.36+/-1.12) compared to both the donor livers and the HCV cirrhosis groups (0.74+/-1.09 and 1.03+/-0.91, respectively). The alpha-smooth muscle actin-positive hepatic stellate cell percentage and fibrosis correlated positively in the post-transplant recurrent HCV hepatitis group and negatively in the HCV cirrhosis group. No difference in the immunohistochemical and morphometrical variables was found between the HCV cirrhosis and HBV cirrhosis groups.

CONCLUSIONS

These results indirectly confirm that, in vivo, alpha-smooth muscle actin expression is a reliable marker of hepatic stellate cells activation which precedes fibrous tissue deposition even in the setting of recurrent HCV chronic hepatitis after liver transplantation, and it could be useful to identify the earliest stages of hepatic fibrosis and monitoring the efficacy of the therapy. In the presence of advanced cirrhosis other factors, rather than alpha-smooth muscle actin-positive hepatic stellate cells, may sustain fibrosis deposition.

Cardiovascular and thrombophilic risk factors for idiopathic sudden sensorineural hearing loss

BACKGROUND

In recent years there has been a significant increase in the diagnosis of sudden sensorineural hearing loss (SSHL) in western, countries with an incidence of 20 of 100,000 people affected every year. No clear causes for this disease have been found thus far, but cochlear ischemia has been hypothesized in patients in whom an infectious episode or acoustic neurinoma have been excluded.

OBJECTIVES

The aim of this case-control study was to investigate a number of acquired and inherited thrombophilic risk factors [antithrombin, protein C and S; factor V (FV) Leiden, FII polymorphism; lupus anticoagulant (LA); anticardiolipin (aCL) antibodies; fasting homocysteine (Hcy); lipoprotein(a) (Lp(a)); plasminogen activator inhibitor-1 (PAI-1)] in addition to cardiovascular risk factors in patients with idiopathic SSHL (ISSHL).

PATIENTS AND METHODS

We investigated 155 patients (67 male/88 female; age: 55 (range 19-79 years) with a diagnosis of ISSHL within 30 days from the onset of symptoms, and 155 controls (67 male/88 female; age 54 (range 19-78 years). Fasting Hcy levels were significantly higher in patients than in controls [11.6 (6.7-60) micromol/L vs. 8.7 (5.0-24) micromol/L] as well as PAI-1 levels [19 (2-95) mg/dL vs. 14.5 (4.0-87) mg/dL]. Lupus anticoagulant was present in 13 of 155 (8.4%) patients; 20 patients (12.9%) had positivity of aCL (four IgM and 16 IgG). In no patient was a deficiency of physiological clotting inhibitors antithrombin, protein C and protein S found. No significant differences between patients and controls were observed for Lp(a) plasma levels [111 (1-1146) mg/L vs. 103 (11-695) mg/L] and for the presence of FV Leiden (4.5% vs. 4.5%) and FII variant G20210A (3.8% vs. 3.2%).

RESULTS AND CONCLUSIONS

Independent risk factors for ISSHL at the multivariate analysis (adjusted for age, sex and the traditional cardiovascular risk factors) were the positivity of aCL: OR 5.6 (95% CI 2.0-15.3); cholesterol levels within the second and third tertiles (with respect to the first tertile): T2 = OR 4.8 (95% CI 1.9-12.6)/T3 = OR 19 (95% CI 7-50.1); PAI-1 and Hcy levels within the third tertile (with respect to the first tertile): OR 20 (95% CI 7.8-78) and OR 4.0 (95% CI 2.0-8.1), respectively. These preliminary data suggest that hypercholesterolemia, hyperhomocysteinemia, elevated PAI-1 levels and anticardiolipin antibodies are associated with ISSHL, so indirectly supporting the hypothesis of a vascular occlusion in the pathogenesis of the disease.

A Randomized Trial of Steroid Avoidance in Renal Transplant Patients Treated with Everolimus and Cyclosporine

In this randomized trial renal transplant recipients were treated with basiliximab, everolimus 3 mg/day, low-dose CsA. At transplantation, patients were randomized to stop steroids at the seventh day (group A) or to continue oral steroids in low doses (group B). Of the 113 patients enrolled, 65 were randomized to group A and 68 to group B. All patients were followed for 2 years. During the study 28 (43%) group A patients required reintroduced corticosteroids. One patient died, in group B. The Graft survival rate was 97% in group A and 90% in group B. There were more biopsy-proven rejections in group A (32% vs 16%; P = .044). The mean creatinine clearance was 54 +/- 21 mL/min in group A vs 56 +/- 22 mL/min in group B. Mean levels of serum cholesterol tended to be lower in group A, but the difference was of borderline significance (191 +/- 91 vs 251 +/- 188 mg/dL; P = .07). Vascular thrombosis (0 vs 5) and pneumonia requiring hospitalization (2 vs 7) tended to be more frequent in group B. Only three cases of CMV infection (1 vs 2) occurred. An immunosuppressive therapy with everolimus and low-dose CsA allows one to obtain excellent renal graft survival and stable graft function at 2 years. Early interruption of steroids in patients treated with this regimen may increase the risk of acute rejection, but neither affects graft survival nor graft function, while possibly reducing the risk of hyperlipemia and vascular thrombosis. About 60% of patients given everolimus and low-dose CsA can definitively stop steroids after 1 week.

Low-dose intramuscular hepatitis B immune globulin and lamivudine for long-term prophylaxis of hepatitis B recurrence after liver transplantation

The combination of lamivudine and hepatitis B immunoglobulins (HBIg) to prevent recurrence of HBV hepatitis has significantly improved the survival of patients transplanted for HBV-related end-stage liver disease. Generally, HBIg are administered intravenously. We evaluated the efficacy, tolerability, and cost savings of long-term intramuscular HBIg and lamivudine in 28 patients (23 men and 5 women), who received liver transplants for acute or chronic HBV-related liver disease. Twelve patients started lamivudine before and 16 at the time of liver transplantation. HBIg were administered intravenously during the first week (50 to 70,000 IU) and intramuscularly thereafter (1200 IU every 3 to 6 weeks) to maintain an HbsAb titer >100 IU/L. Mean follow-up was 20 +/- 13 months. Only one patient experienced HBV recurrence (9 months after transplantation). This patient had failed to follow the scheduled prophylaxis. Cumulative survival at 3 years was 83%. Intramuscular HBIg were well tolerated in all cases. Cost analysis comparing intramuscular vs intravenous HBIg administration showed that 39,490 Euros were saved per patient per year. These preliminary results show that low-dose intramuscular HBIg and lamivudine are efficacious and cost-effective for long-term prophylaxis of hepatitis B recurrence after liver transplantation.

Sequential treatment for Helicobacter pylori does not share the risk factors of triple therapy failure

BACKGROUND

Predicting factors for the outcome of conventional Helicobacter pylori triple therapy have been identified. Of these, the presence of the CagA gene is a strong predictor of successful treatment. Our preliminary data show that this factor becomes irrelevant when sequential therapy is used.

AIM

To identify predicting factors for the outcome of H. pylori eradication using two therapeutic schemes (triple and sequential) of equal duration (10 days).

METHODS

Ninety-six patients with H. pylori infection were randomly assigned to receive one of the following therapeutic schemes: group A: rabeprazole (20 mg b.d.) plus amoxicillin (1 g b.d.) for 5 days, followed by rabeprazole (20 mg b.d.) plus tinidazole (500 mg b.d.) and clarithromycin (500 mg b.d.) for a further 5 days; group B: rabeprazole (20 mg b.d.) plus amoxicillin (1 g b.d.) and clarithromycin (500 mg b.d.) for 10 days. Age, sex, smoking, endoscopic and histological findings, and CagA and VacA status were considered as candidates for a model of multivariate analysis which used therapeutic outcome as the dependent variable. CagA and VacA status were assessed by polymerase chain reaction on DNA isolated from gastric antral specimens.

RESULTS

The sequential scheme was significantly more effective than prolonged triple therapy (P < 0.05). Smoking (P < 0.001) and the absence of the CagA gene (P < 0.05) were significantly associated with the failure of triple therapy, but the effectiveness of sequential treatment was not predicted by these factors.

CONCLUSION

Our data suggest that sequential therapy is not affected by bacterial and host factors which have, until now, predicted the outcome of conventional eradication treatments.

Helicobacter pylori strains and histologically-related lesions affect the outcome of triple eradication therapy: a study from southern Italy

BACKGROUND

Certain evidence suggests that Helicobacter pylori strains expressing genes for cytotoxin production show a higher sensitivity than non-cytotoxic organisms to eradication treatment. No data are available on the involvement of bacterium-related lesions in different therapeutic outcomes.

AIMS

(i) To investigate whether differences in eradication rates may be related to the different expression of virulent strains (cagA, vacA, iceA) in patients undergoing proton pump inhibitor-based triple therapy, and (ii) to evaluate whether therapeutic outcome may be affected by bacterium-induced gastric lesions.

METHODS

One hundred and ten H. pylori-positive subjects were enrolled. H. pylori was genotyped by polymerase chain reaction. Treatment consisted of lansoprazole-amoxicillin-clarithromycin, twice daily for 1 week. Eradication was checked by urea breath test.

RESULTS

The eradication rate was 70%, and the absence of cagA was associated with unsuccessful treatment. No difference between the groups with successful and unsuccessful eradication was found with regard to vacA and iceA. Lympho-epithelial lesions and fibrosis were associated with unsuccessful treatment.

CONCLUSIONS

The present data confirm the importance of cagA (but not vacA and iceA) as a predictor of successful eradication. When fibrosis and lympho-epithelial lesions are present, therapy appears to be less effective. Therefore, these histological features may be involved in an unsuccessful therapeutic outcome.

Demonstration of a direct stimulatory effect of bile salts on rat colonic epithelial cell proliferation

BACKGROUND

Despite the clear demonstration that an increase in faecal bile salt concentration can augment colonocyte proliferation, it is still controversial whether bile salts act on these cells as direct mitogens or by inducing a damage-related proliferative response. The goal of this study was to define the mechanism mediating the proliferative effect of bile salts on rat colonocytes.

METHODS

Faecal bile salt concentration was increased by feeding rats on diets enriched with either bile salts or fats. Colonic mucosa proliferating cell nuclear antigen (PCNA) expression, histology and apoptosis, and faecal water cytolytic activity were evaluated to assess proliferation and direct or indirect signs of mucosal damage.

RESULTS

Compared to standard diet, chenodeoxycholate-, deoxycholate- and fat-enriched diets produced a significant increase in both faecal water total bile salt concentration (46.0 versus 124.1, 145.9 and 498.5 micromol/L, respectively) and percentage of PCNA-positive nuclei (30.5, versus 37.7, 33.9 and 47.1, respectively) that appeared significantly correlated (r = 0.8; P < 0.001). Chenodeoxycholate and deoxycholate fed animals showed colonic mucosa histology and faecal water cytolytic activity similar to controls, with a significantly reduced apoptotic index. Rats fed on high fat diet, however, showed a mild inflammatory infiltrate associated with an increased apoptosis and faecal water cytolytic activity, all conditions not apparently determined by the increased faecal water total bile salt concentration.

CONCLUSIONS

The results obtained in this study demonstrate that bile salts act as direct mitogens on colonic epithelial cells.

Living kidney transplantation between spouses: results in 100 cases

The use of unrelated living donors in kidney transplantation is still controversial but many transplant centres have accepted this procedure. The main argument against this approach is usually an ethical one. Because of this, at our institution we accept biologically unrelated donors only if they have an emotional closeness to the recipient. From January 1983 to October 1993, out of 654 kidney transplantations we performed at our institution, 364 kidney allografts were from living donors. Of these living donors, 245 were first-degree relatives of the recipient (LRD) while 119 were unrelated (LURD); 100 cases were spouses--wife to husband in 76 cases and husband to wife in 24 cases. Statistical analysis of the results (chi-square) revealed actuarial patient and graft survival rates of 89.8% and 86.8% at 1 year, 82.9% and 72.3% at 5 years and 72.3% and 60.3% at 9 years, respectively. In our series, the result of living donor kidney transplantation in this group were similar to those obtained in the LRD group, while they were significantly better than those from cadaver donors (P = 0.003). In conclusion, cadaver organs given the shortage of kidney transplantation between spouses may be a good alternative and can be performed successfully, providing a "gift of life" for both the patient and the family.

Detection of T suppressor cells in patients with organ allografts

Specific immunosuppression of host's immune response to donor HLA antigens has been a major goal to clinical transplantation. Recent evidence has been accumulating to show that a distinct population of T cells expressing the CD8(+) CD28(-) phenotype display suppressor function and inhibit Th activation and proliferation by modulating the APC function. To assess the presence of Ts in transplant recipient's circulation, we have developed a flow cytometry method that measures the expression of costimulatory molecules on donor APC exposed to recipient Th and Ts. Our results demonstrate that quantitation of the capacity of CD8(+) CD28(-) T cells from patient circulation to suppress the activation of costimulatory molecules (CD80, CD86) on donor APC offers a reliable tool for monitoring specific immunosuppression against the graft in solid organ transplantation.

Duodenogastric reflux and gastric mucosal polyamines in the non-operated stomach and in the gastric remnant after Billroth II gastric resection. A role in gastric carcinogenesis?

BACKGROUND

The relationship between bile reflux and gastric cancer is not defined. In order to verify whether a relationship exists, we evaluated the duodenogastric reflux and the mucosal polyamines concentration, polycation compounds actively involved in cell proliferation, in the non-operated stomach and in gastric remnant after Billroth II gastric resection, a precancerous condition.

MATERIALS AND METHODS

The study was performed on three groups of subjects: A) 43 subjects with slight dispeptic symptoms, never operated on; B) 54 cholecystectomized subjects; C) 38 subjects operated on Billroth II gastric resection for duodenal ulcer. Duodenogastric reflux was assessed by measuring the concentration of bile acids in gastric juice and expressed as Fasting Bile Reflux in micromol/hour. Gastric mucosal polyamine concentration was assessed by High Performance Liquid Chromatography and expressed in nmol/mg of proteins.

RESULTS

The lowest levels of Fasting Bile Reflux (7.95 micromol/hour) and polyamines (7.09 nmol/mg proteins) were observed in subjects never operated on. The middle values were present after cholecystectomy (Fasting Bile Reflux = 18 micromol/hour; polyamines = 8.14 nmol/mg proteins). The highest values were observed after Billroth II gastric resection (Fasting Bile Reflux = 830 micromol/hour; polyamines 11.74 nmol/mg proteins) (Kruskal-Wallis test, p = 0.0001). There was a positive correlation between Fasting Bile Reflux and polyamines (Spearman's rank = 0.33; p = 0.0008).

CONCLUSIONS

High levels of duodenogastric reflux observed after Billroth II gastric resection are associated with high polyamine concentration in the gastric mucosa. Bile reflux can be considered an important causal factor of the increased risk of gastric stump cancer after Billroth II gastric resection.

Use of macroporous polypropylene filter to allow identification of bacteria by PCR in human fecal samples

The detection of pathogenic bacteria directly in human fecal specimens by PCR, requires removal of PCR-inhibitory substances. To investigate whether five different macroporous filters (polypropylene, nylon, polyester, polyethylene, fluorocarbon) could retain polysaccharides, major PCR inhibitors, an in vitro model and human fecal samples were used. The in vitro model consisted of Xanthum gum solutions (3 mg/ml PBS), a bacterial polysaccharide, to which Helicobacter pylori cells were added. Fecal samples from healthy volunteers were spiked with H. pylori and Mycobacterium paratuberculosis cells. Polysaccharide concentrations were significantly reduced only by the polypropylene but not by the other filters. Accordingly, both Xanthum gum solutions and spiked fecal specimens became PCR positive only after filtration with the polypropylene filter. We conclude that this filter can be used to prepare a bacterial DNA template suitable for PCR analysis from human feces.

Antioxidant effect of short-term hormonal treatment in postmenopausal women

OBJECTIVES

Recent studies have shown that estrogens alone or in association with progestins can exert an antioxidant effect on Low-Density Lipoprotein (LDL) and lipids of platelet membranes. It has been demonstrated that the oxidative modification of LDLs also involving the formation of lipid peroxides, exerts several biological effects that may contribute to the onset and progression of cardiovascular diseases. Therefore, the aim of our study was to evaluate the effect of short-term treatment with oral estrogens alone and estrogens plus progestin on endogenous and copper-induced serum levels of lipid peroxides in postmenopausal women.

METHODS

Thirty-nine postmenopausal women were randomly divided into three groups: group I was treated with oral conjugated equine estrogens (CEE) for 21 days; group II received oral CEE for 21 days and, after 14 days of this treatment, 5 mg/day of medrogestone was added for 7 days; group III did not receive any therapy (controls). Endogenous and copper-induced serum levels of lipid peroxides were determined before and after 21 days of treatment in the two treated groups and in the control group.

RESULTS

The serum endogenous levels of lipid peroxides in postmenopausal women did not change after short-term treatment with hormone replacement therapy. Moreover, copper-induced serum levels of lipid peroxides significantly decreased after therapy in both groups I and II.

CONCLUSIONS

Our data show that hormone replacement therapy (HRT) inhibits lipid peroxidation and may play a role in preventing cardiovascular diseases.

Polyamine profile in human gastric mucosa infected by Helicobacter pylori

BACKGROUND

Several studies have demonstrated increased gastric epithelial cell proliferation associated with Helicobacter pylori infection, which is reversed after bacterium eradication. Among the substances involved in cell proliferation and differentiation, polyamines are a group of polycations found in high concentrations both in normal and neoplastic cells.

AIMS

Of the study were: a) to examine the influence of Helicobacter pylori infection on the polyamine profile in the gastric antrum and body, by comparing infected, to uninfected, patients, b) to evaluate the effect of successful and unsuccessful bacterium eradication on polyamine levels.

PATIENTS AND METHODS

Twenty-six consecutive dyspeptic patients (20 Helicobacter pylori positive and 6 Helicobacter pylori negative) undergoing gastroscopy were enrolled. Polyamines were evaluated in antral and body biopsies by High Performance Liquid Chromatography.

RESULTS

Antral and body biopsies from Helicobacter pylori positive patients contained higher polyamine levels than those from Helicobacter pylori negative subjects. In Helicobacter pylori positive patients, the baseline polyamine levels were higher in the antrum than in the body. In Helicobacter pylori negative subjects, levels in the two stomach regions were similar. After therapy, polyamine levels decreased in patients with successful eradication, whereas these levels remained unchanged in patients in whom infection persisted.

CONCLUSIONS

These findings indicate enhanced antral cellular proliferation linked to the presence of Helicobacter pylori and add weight to the postulation of an association between Helicobacter pylori infection and increased risk of neoplastic changes in gastric antral mucosa. Differences in antral and body levels of polyamines may also be considered as a further indication of the different mucosal reactivity between the two regions of the stomach towards bacterial invasion.

Prognostic value of low density lipoprotein receptor expression in colorectal carcinoma

Cancer cells require more cholesterol than normal cells. This requirement seems to be satisfied by a higher HMG-CoA reductase activity or a higher activity of low density lipoprotein receptor (LDLR). We investigated the prognostic value of LDLR in colorectal carcinoma (CRC) patients. The LDLR was evaluated in 90 patients with CRC by ELISA. The survival time and the relative risk of prognostic factors were analyzed by Kaplan-Meier estimates and Cox proportional hazard model. Thirty three cases were LDLR positive (+), while 57 LDLR negative (-). The survival of LDLR(-) patients was shorter than that of LDLR(+). By Cox model, the absence of LDLR and time until metastasis resulted significantly associated with the CRC-related survival. The absence of LDLR in CRC predicts a shorter survival.

[Multifocal inflammatory pseudotumor of the liver]

Inflammatory pseudotumor of the liver is a rare entity of unknown etiology; fewer than 80 cases have been reported in the world literature. Its appearance on the computerized tomography, ultrasound and magnetic resonance have been previously described as nonspecific, and clinical presentation is not helpful in the diagnosis. This is why the diagnosis usually is made after laparotomy and often after the excision of the tumor. Several recent reports show that drug therapy is effective and lead to tumor regression, while other authors believe that an aggressive approach should be taken, due to the potential adverse impact of its vascular invasive and biliary obstructive nature. Herein we describe a case of this clinical entity, which occurred in a 52 years old patient, where the operative examination showed bilobar involvement, treated with right hepatectomy and contra-lateral tumor excision in the clinical suspect of hepatocellular carcinoma. The detailed clinical, radiological and pathological picture is described. At 6 months follow-up the patient conditions are excellent. On the basis of the available literature, we discuss the clinical features and the therapeutical problems of such rare clinical entity, and propose a selected use of liver biopsy when the clinical suspicion of pseudotumor can be considered, in order to achieve a preoperative diagnosis and therefore to avoid surgery.

[A case of multifocal inflammatory pseudotumor of the liver]

INTRODUCTION

The inflammatory pseudotumor (IPT) of the liver is a tumor-like lesion of unknown etiology and pathogenesis. Non infectious by definition the lesion is considered to be a long-lasting inflammatory process.

CASE

In this report we describe a multifocal liver pseudotumor of a 52 year man who underwent a selective hepatectomy for a clinical and radiological suspicion of a liver cell carcinoma.

RESULTS

Grossly the masses consisted of rubbery grey-yellowish nodules well-circumscribed from the liver parenchyma. Histologic examination revealed a double shaped cellular population surrounded by a thin rim of collagen fibres. The main population consisted of fibroblasts and histiocytes with no atypias or mitoses, arranged in a storiform or fascicular pattern; the second population consisted of a mixed population of lymphocytes, plasma cells, neutrophils and monocytes. Fibroblasts and histiocytes revealed diffuse positive immunostaining for vimentin and focal immunostaining for cytokeratin and desmin. The histiocytes were also CD68, CD18, CD14 and CD4 positive.

CONCLUSIONS

Our case reveals same histological and immunohistochemical features already reported in literature. Primary and metastatic tumors involving the liver need to enter in the differential diagnosis but IPT lacks features of malignancy and the cell population is mixed. Although there is no specific marker for this lesion in cases featuring malignancy immunohistochemistry may be useful for a differential diagnosis: S-100 in cases of neurofibrosarcomas, actin and myosin for rhabdomyosarcomas, cytokeratin for epithelial tumors.

alpha-Tocopherol and beta-carotene serum levels in post-menopausal women treated with transdermal estradiol and oral medroxyprogesterone acetate

Estrogens exert a protective effect against atherosclerosis. It is well known that hormone replacement therapy (HRT) can effectively decrease LDL-cholesterol and increase HDL-cholesterol and Apo-Al serum levels. Some recent studies have suggested that estrogens alone or in association with progestins may exert an antioxidant effect on lipids. Besides sex steroids, also vitamins exert an antioxidant effect on LDL and may preserve the endogenous antioxidants of LDL. The aim of our study was to evaluate whether HRT can improve alpha-tocopherol and beta-carotene serum levels in post-menopausal women. Fifteen postmenopausal women with climacteric symptoms were treated with 50 micrograms/24 h estradiol transdermally applied twice a week for 21 days. A daily dose of 10 mg oral medroxyprogesterone acetate was added for 12 days in each treatment cycle. This therapy lasted 6 months. A significant reduction was found in total cholesterol and LDL-cholesterol after treatment. Besides, our study has shown that alpha-toc/LDL and beta-car/LDL ratios significatively increased after treatment, while alpha-tocopherol and beta-carotene serum levels did not change significantly after therapy. These preliminary findings suggest that HRT can preserve the content of alpha-tocopherol and beta-carotene in LDL particles and keep the LDL in a reduced antioxidant state.