5T4 oncofetal antigen is expressed in high risk of relapse childhood pre-B acute lymphoblastic leukemia and is associated with a more invasive and chemotactic phenotype

Although the overall prognosis in childhood acute lymphoblastic leukemia (ALL) is good, outcome after relapse is poor. Recurrence is frequently characterized by the occurrence of disease at extramedullary sites, such as the central nervous system and testes. Subpopulations of blasts able to migrate to such areas may have a survival advantage and give rise to disease recurrence. Gene expression profiling of 85 diagnostic pre-B-ALL bone marrow samples revealed higher 5T4 oncofetal antigen transcript levels in cytogenetic high-risk subgroups of patients (P<0.001). Flow cytometric analysis determined that bone marrow from relapse patients have a significantly higher percentage of 5T4-positive leukemic blasts than healthy donors (P=0.005). The high-risk Sup-B15 pre-B-ALL line showed heterogeneity in 5T4 expression, and the derived, 5T4(+) (Sup5T4) and 5T4(-) (Sup) subline cells, displayed differential spread to the omentum and ovaries following intraperitoneal inoculation of immunocompromised mice. Consistent with this, Sup5T4 compared with Sup cells show increased invasion in vitro concordant with increased LFA-1 and VLA-4 integrin expression, adhesion to extracellular matrix and secretion of matrix metalloproteases (MMP-2/-9). We also show that 5T4-positive Sup-B15 cells are susceptible to 5T4-specific superantigen antibody-dependent cellular toxicity providing support for targeted immunotherapy in high-risk pre-B-ALL.

Diet and feeding niches of juvenile Gadus morhua, Melanogrammus aeglefinus and Merlangius merlangus during the settlement transition in the northern North Sea

A study on the feeding ecology of juvenile cod Gadus morhua, haddock Melanogrammus aeglefinus and whiting Merlangius merlangus during the pelagic to demersal transition was carried out on fishes sampled throughout their settlement season at a local nursery ground in the north-western North Sea, off the Scottish east coast. A comprehensive quantitative taxonomic analysis of the diets, as described in the paper, showed the emergence of distinctive feeding niches, minimizing the potential for competition between species and size categories. The diet of the juveniles changed with fish size, water depth, time of year and distance offshore. Small G. morhua were present in the study area earlier in the season, settled further inshore and ate a higher proportion of pelagic prey (copepods) and as size increased they moved into deeper waters and targeted larger, more benthic prey. As M. aeglefinus grew larger and moved into deeper waters, a diet of largely copepods, amphipods, pelagic Ammodytes spp., cyprids and pelagic gastropods evolved to one dominated predominantly by fishes and benthic invertebrates. In the case of M. merlangus, widespread ages and sizes throughout the sampling season, a consequence of their more protracted spawning season, resulted in dietary changes which were more likely to be influenced by seasonal changes in the prey field, in addition to developmental (size) changes, than the diets of the other two species.

The potential role of T-cell memory distribution as predisposing factor for rejection in heart transplant recipients

CD4 T cells play a significant role in the pathogenesis of rejection, providing help to alloreactive CD8 and B cells, however, the exact contribution of each memory compartment in vivo has not been defined. They are also important for the maintenance of tolerance due to regulatory activity of specialized subsets. In this study, we assessed changes in frequencies of functionally distinct lymphocyte subsets of peripheral blood (PBLs) in 26 heart transplant recipients (HT) in association with rejection episodes. Patients who developed rejection (n = 7), namely Grade 3B (n = 1), 3A (n = 4), or 2 (n = 2), in comparison with those with stable graft function displayed at baseline (pre-HT) higher percentages of naive (CCR7+CD45RA+) CD4 T cells (median 48 vs 36.6%; P = .035) and lower percentages of central memory (CCR7+CD45RA-) CD4 T cells (33.3 vs 46.5%; P = .035). At 30 days post-HT, CD4/CD127(low)FoxP3+ T cells were significantly reduced among patients with rejection episodes (0.84 vs 2.15%; P = .042). CD8 final effector T cells were increased at 90 days post-HT among those patients who experienced rejection (TEM2: 60.8 vs 31.9%; P < .1), at the expense of shrinking CD8 central memory compartment (TCM: 8.6 vs 12.9%; P = .046). The potential role of T-cell memory distribution should be further evaluated in HT patients as possible markers to discriminate patients at risk for rejection.

Evaluation of initial virological response to adefovir and development of adefovir-resistant mutations in patients with chronic hepatitis B

The aims of the present study were to assess initial virological response (IVR) to adefovir (ADV) treatment for chronic hepatitis B, to identify patients with suboptimal response and to determine the incidence of ADV-resistant mutants. All patients treated with ADV for at least 12 months were evaluated for virological response and ADV resistance. IVR was defined as a reduction > or = 4 log10 IU/mL in hepatitis B virus (HBV)-DNA at month 6. Forty-two patients were analysed. Mean treatment duration was 23 +/- 7 months; 50% had prior lamivudine (LAM) therapy (LAM resistance 62%); 88% were hepatitis B e antigen (HBeAg)-negative; and 76% carried genotype D. IVR was seen in 40.5% of patients. Higher baseline ALT level was the only factor associated with IVR (P = 0.043). Patients with IVR achieved undetectable HBV-DNA at month 12 in 77% of cases compared with only 5% of those without IVR (P < 0.001). Five (12%) patients developed ADV-resistant mutations: rtN236T in four cases and one case with an rtV207L change, which has not been previously reported. This mutation was accompanied by viral rebound and alanine aminotransferase (ALT) flare. The cumulative probability of ADV-resistant mutations at 12 and 24 months was 5% and 17% respectively. IVR defined as a reduction > or = 4 log10 IU/mL in HBV-DNA at month 6 is a useful tool to predict virological response at month 12 and to identify patients with suboptimal response to ADV. Cumulative probability of ADV resistance is higher than previously reported for nucleos(t)ide-naïve patients.

Evaluation of initial virological response to adefovir and development of adefovir-resistant mutations in patients with chronic hepatitis B

The aims of the present study were to assess initial virological response (IVR) to adefovir (ADV) treatment for chronic hepatitis B, to identify patients with suboptimal response and to determine the incidence of ADV-resistant mutants. All patients treated with ADV for at least 12 months were evaluated for virological response and ADV resistance. IVR was defined as a reduction > or = 4 log10 IU/mL in hepatitis B virus (HBV)-DNA at month 6. Forty-two patients were analysed. Mean treatment duration was 23 +/- 7 months; 50% had prior lamivudine (LAM) therapy (LAM resistance 62%); 88% were hepatitis B e antigen (HBeAg)-negative; and 76% carried genotype D. IVR was seen in 40.5% of patients. Higher baseline ALT level was the only factor associated with IVR (P = 0.043). Patients with IVR achieved undetectable HBV-DNA at month 12 in 77% of cases compared with only 5% of those without IVR (P < 0.001). Five (12%) patients developed ADV-resistant mutations: rtN236T in four cases and one case with an rtV207L change, which has not been previously reported. This mutation was accompanied by viral rebound and alanine aminotransferase (ALT) flare. The cumulative probability of ADV-resistant mutations at 12 and 24 months was 5% and 17% respectively. IVR defined as a reduction > or = 4 log10 IU/mL in HBV-DNA at month 6 is a useful tool to predict virological response at month 12 and to identify patients with suboptimal response to ADV. Cumulative probability of ADV resistance is higher than previously reported for nucleos(t)ide-naïve patients.

Production of intracellular IL-2, TNF-alpha, and IFN-gamma by T cells in B-CLL

BACKGROUND

Recent evidence indicates that the slowly expanding population of CD5(+) B cells that characterizes B-cell chronic lymphocytic leukemia (B-CLL) could be related to defects in the response to cytokine produced by T cells that regulate apoptosis. We studied the intracellular expressions of interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma) in T-helper 1 cells (Th1 response) of B-CLL.

METHODS

Peripheral blood mononuclear cells from 21 healthy individuals and purified T cells from 21 early-stage and 15 late-stage B-CLL patients were activated with phorbol myristate acetate and ionomycin. The Th1 cytoplasmic cytokines were evaluated in CD4(+) and CD8(+) T cells by flow cytometry.

RESULTS

The percentages of CD4(+) and CD8(+) T cells positive for IL-2 were significantly lower in B-CLL patients than in healthy individuals (P = 0.030 and 0.049, respectively). No significant differences in TNF-alpha or IFN-gamma intracellular expressions were found between patients and healthy individuals. TNF-alpha- and IFN-gamma-expressing CD8 T cells were disease stage dependent, being significantly higher in late-stage patients (P < 0.001 for both cytokines).

CONCLUSIONS

Our present observations suggested that Th1 cytokines may be of major importance in the pathogenesis of B-CLL.

Endoscopic ligation compared with combined treatment with nadolol and isosorbide mononitrate to prevent recurrent variceal bleeding

BACKGROUND

After an episode of acute bleeding from esophageal varices, patients are at high risk for recurrent bleeding and death. We compared two treatments to prevent recurrent bleeding--endoscopic ligation and combined medical therapy with nadolol and isosorbide mononitrate.

METHODS

We randomly assigned 144 patients with cirrhosis who were hospitalized with esophageal variceal bleeding to receive treatment with endoscopic ligation (72 patients) or the combined medical therapy (72 patients). Sessions of ligation were repeated every two to three weeks until the varices were eradicated. The initial dose of nadolol was 80 mg orally once daily, with adjustment according to the resting heart rate; isosorbide mononitrate was given in increasing doses, beginning at 20 mg once a day at bed time and rising over the course of one week to 40 mg orally twice a day, unless side effects occurred. The primary end points were recurrent bleeding, complications, and death.

RESULTS

The median follow-up period was 21 months. A total of 35 patients in the ligation group and 24 in the medication group had recurrent bleeding. The probability of recurrence was lower in the medication group, both for all episodes related to portal hypertension (P=0.04) and for recurrent variceal bleeding (P=0.04). There were major complications in nine patients treated with ligation (seven had bleeding esophageal ulcers and two had aspiration pneumonia) and two treated with medication (both had bradycardia and dyspnea) (P=0.05). Thirty patients in the ligation group died, as did 23 patients in the medication group (P=0.52). The probability of recurrent bleeding was lower for patients with a hemodynamic response to therapy, defined as a decrease in the hepatic venous pressure gradient of more than 20 percent from the base-line value or to less than 12 mm Hg (18 percent, vs. 54 percent in patients with no hemodynamic response at one year; P<0.001), and the probability of survival was higher (94 percent vs. 78 percent at one year, P=0.02).

CONCLUSIONS

Combined therapy with nadolol and isosorbide mononitrate is more effective than endoscopic ligation for the prevention of recurrent bleeding and is associated with a lower rate of major complications. A hemodynamic response to treatment is associated with a better long-term prognosis.

Prognosis of patients with acute renal failure without cardiopathy

BACKGROUND

The outcome for children with acute renal failure (ARF) may be poor. However, relatively few published studies have considered prognosis of these patients.

METHODS

We prospectively studied, from 1978 to 1998, 92 such children without heart disease to try to identify risk factors for mortality.

RESULTS

Forty five per cent of children with tumours, shock, and other causes died compared with none of those with a primary urinary tract related problem. ARF did not seem to be the cause of death in any case. Univariate analysis showed that in the non-primary urinary problem group (55 cases), patients with hypotension, high values of BUN or creatinine, or who needed mechanical ventilation or dialysis, had a poor outcome. Multivariate analysis showed that probability of death can be estimated using the following score: -0.02 + 0.28 (hypotension) + 0.19 (ventilation) + 0.27 (dialysis) + 0.01 (BUN).

CONCLUSIONS

Mortality of patients with ARF was related to aetiology, the need for dialysis and/or ventilator use, hypotension, and BUN values.

Factors affecting biodegradation of 2-chlorophenol by Alcaligenes sp. in aerobic reactors

The influence of variations in carbon source concentration, cell inocula, pH, presence of other substrates, and other organisms on the biodegradation of 2-chlorophenol (2-CP) was studied for Alcaligenes sp. isolated from natural sources. Assays of biodegradation were performed in batch and continuous-flow fluidized-bed aerobic reactors. Evaluation of biodegradation was performed by determining total phenols, chemical oxygen demand (COD), and 2-CP by ultraviolet (UV) spectrophotometry. Measurement of microbial growth was carried out by the plate count method. Bioassays of acute toxicity were performed to evaluate detoxification by using Daphnia magna. Results obtained show that under batch conditions with initial inocula of 10(6) cells/mL the strain grew exponentially with 100, 200, and 300 mg/L of 2-CP within 48 hr. A lag period was observed with low cell density inocula (10(5) cells/mL). The strain showed marked delay in the biodegradation of 2-CP at pH 5. Removal of target substrate from mixtures containing other carbon sources demonstrated the possibility of concurrent growth. Mineralization of 2-CP was assessed by gas chromatography carried out at the end of the batch assays and at the exit of the continuous-flow reactor. The presence of other organisms (bacteria, rotifers, ciliate, and algae) that developed in the fluidized-bed reactor did not affect the efficacy of the biodegradation of 2-CP. The removal of 2-CP in the two assayed systems was over 97% in all cases. Toxicity was not detected at the exit of the continuous reactor.

Retreatment for 24 vs 48 weeks with interferon-alpha2b plus ribavirin of chronic hepatitis C patients who relapsed or did not respond to interferon alone

We assessed the efficacy of interferon (IFN) plus ribavirin over 24 or 48 weeks for the retreatment of patients with chronic hepatitis C who had relapsed or did not respond to a previous course of IFN. One-hundred and twenty patients (69 non-responders and 51 relapsers) were randomly assigned to receive IFN-alpha2b (3 million units thrice weekly) plus ribavirin (1,000-1,200 mg per day) for 24 weeks (group A: 58 patients) or 48 weeks (group B: 62 patients). Treatment was discontinued at week 12 if the alanine aminotransferase (ALT) level remained elevated. The rate of sustained response was 15.5% in group A and 37.1% in group B (P = 0.013). Relapsers treated for 48 weeks had a sustained response rate of 66.6% compared with a sustained response rate of only 25% in those treated for 24 weeks (P = 0.004). Moreover, a sustained response was seen in 14.3% of non-responders treated for 48 weeks and in 8.8% of those treated for 24 weeks (P = 0.71). Fifty-three per cent of patients with a normal ALT level and undetectable hepatitis C virus (HCV) RNA at week 12 had a sustained response compared with 14% of those who were HCV RNA positive at week 12 (P < 0.001). Independent predictive factors of sustained response were: therapy for 48 weeks (P = 0.0026), relapse after IFN treatment (P = 0.0006), loss of HCV RNA at week 12 (P = 0.0008) and HCV genotype non-1 (P = 0.024). Hence, in patients with chronic hepatitis C who failed to respond to a previous course of IFN monotherapy, combination therapy with IFN plus ribavirin for 48 weeks seems to be more effective than IFN plus ribavirin for 24 weeks.