DNA prime protein boost strategies protect cattle from bovine viral diarrhea virus type 2 challenge

At present, infections with bovine viral diarrhea virus (BVDV) type 2 occur nearly as frequently as those with BVDV type 1, so development of vaccines that protect cattle from both type 1 and type 2 BVDV has become critical. In this study, we compared various DNA prime-protein boost vaccination strategies to protect cattle from challenge with BVDV-2 using the major protective antigen of BVDV, glycoprotein E2. Calves were immunized with a plasmid encoding either type 1 E2 (E2.1) or type 2 E2 (E2.2) or with both plasmids (E2.1+E2.2). This was followed by a heterologous boost with E2.1, E2.2 or E2.1 and E2.2 protein formulated with Emulsigen and a CpG oligodeoxynucleotide. Subsequently, the calves were challenged with BVDV-2 strain 1373. All vaccinated calves developed both humoral and cell-mediated immune responses, including virus-neutralizing antibodies and IFN-gamma-secreting cells in the peripheral blood. Depletion studies showed that CD4+ T cells were responsible for IFN-gamma production. Furthermore, the calves vaccinated with either the E2.2 or the E2.1+E2.2 vaccines were very well protected from challenge with BVDV-2, having little leukopenia and showing no weight loss or temperature response. In addition, the animals vaccinated with the E2.1 vaccine were partially protected, so there was a certain level of cross-protection. These data demonstrate that a vaccination strategy consisting of priming with E2.2 or E2.1+E2.2 DNA and boosting with E2.2 or E2.1+E2.2 protein fully protects cattle from BVDV-2 challenge.

Polar Kerr-effect measurements of the high-temperature YBa2Cu3O6+x superconductor: evidence for broken symmetry near the pseudogap temperature

The polar Kerr effect in the high-T_(c) superconductor YBa2Cu3O6+x was measured at zero magnetic field with high precision using a cyogenic Sagnac fiber interferometer. We observed nonzero Kerr rotations of order approximately 1 microrad appearing near the pseudogap temperature T(*) and marking what appears to be a true phase transition. Anomalous magnetic behavior in magnetic-field training of the effect suggests that time reversal symmetry is already broken above room temperature.

A magnetic resonance imaging study of iron overload in hemopoietic stem cell transplant recipients with increased ferritin levels

We performed a study of magnetic resonance imaging (MRI) assessment of hemosiderosis in the heart (T2/T2*), liver (T2*), pancreas (T2*), and pituitary gland (T2/T2*/SIR) in 20 hemopoietic stem cell transplant (HSCT) recipients (median peak ferritin levels 7615 pmol/L, range 3411 to 33000 pmol/L). MRI reading was abnormal in the heart (5%), liver (85%), pancreas (40%), and pituitary gland (55%). The heart T2 correlated with peak ferritin levels (P=.024), while the liver T2* correlated with current ferritin (P=.038) values only. Pancreatic T2* values correlated with pituitary T2 and signal intensity ratio values. The ejection fraction was abnormal in 10% of cases and did not correlate with ferritin level or heart T2. The peak liver enzymes correlated with peak ferritin (P=.025), but the current liver enzymes were mostly normal. Pancreatic assessments (fasting glucose, insulin, beta cell function, insulin reserve, and C-peptide) and pituitary growth hormone axis assessments (growth hormone, insulin growth factor-1, and insulin growth factor binding protein-3) were abnormal in 40% to 70% of cases. They were unrelated to pancreas or pituitary MRI values. Interestingly, endocrine assessments correlated with heart T2 values and peak (but not current) ferritin levels. We concluded that iron overload may contribute to organ damage after HSCT, and MRI assessment may be useful in its detection and treatment monitoring.

Epigenetic dysregulation of Wnt signaling pathway in multiple myeloma

Wnt signaling has recently been implicated in carcinogenesis. We studied the activity of Wnt signaling and the methylation status of WIF1, DKK3, APC, SFRP1, SFRP2, SFRP4 and SFRP5 by methylation-specific PCR in myeloma cell lines and primary myeloma samples. Of the four cell lines, Wnt signaling was constitutively activated in LP1 and WL2, correlating with hypermethylation and hence silencing. Moreover, 5-aza-2'-deoxycytidine treatment of these two cell lines showed progressive demethylation of methylated Wnt inhibitors, re-expression of transcripts and downregulation of Wnt signaling. In both LP1 and WL2 cells, multiple Wnts and Fzs were simultaneously expressed. Treatment of WL2, in which SFRP1 was completely methylated, with recombinant secreted Frizzled-related protein 1 (SFRP1) induced downregulation of Wnt signaling and inhibition of proliferation. In primary myeloma samples, 42% patients had methylation of at least one of these seven genes, of which 61.9% had > or = 2 genes methylated. In conclusion, Wnt signaling is constitutively activated in myeloma, associated with methylation silencing of one or multiple soluble Wnt antagonists. An autocrine loop regulating Wnt signaling was demonstrated in the myeloma plasma cells, in which cellular proliferation was efficiently inhibited by recombinant SFRP1. Methylation study of a panel of genes, regulating a cellular pathway instead of isolated genes, is important.

XELOX causes less disabling peripheral neuropathy than FOLFOX 4 for Chinese colorectal cancer patients

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Background: Infusional 5-FU plus leucovorin and oxaliplatin (FOLFOX4) is an efficacious treatment for colorectal cancer patients in both the adjuvant and metastatic settings. However, around 10% of FOLFOX4 patients will develop with disabling grade 3–4 neuropathy. Recent phase II studies have demonstrated that oral capecitabine in combination with oxaliplatin (XELOX) is as least as effective as FOLFOX4 for colorectal cancer. In this study, we assessed the toxicities of XELOX in Chinese colorectal cancer patients. Methods: Patients who received XELOX at Queen Mary Hospital, Hong Kong between November 2004 and November, 2006 were analyzed. Toxicities were graded by the National Cancer Institute common toxicity system. Results: Thirty-five patients received XELOX on an outpatient basis during the study period: Twenty-four as adjuvant therapy and 11 as treatment for metastatic disease. The most common side effect was grade 1–2 peripheral neuropathy which occurred in 77% of patients. No grade 3–4 neuropathy was reported. Grade 1–2 diarrhea and palmar-plantar erythrodysesthesia (PPE) also occurred in 40 % and 37 % of patients, respectively. The commonest grade 3 toxicities was diarrhea which occurred in 17% of the patients followed by 9% of patients experienced grade 3 PPE. No grade 4 toxicities were reported in our patient’s cohort. Overall, only one (3%) patient had neutropenic sepsis and 36% of patients required 20% reduction in drug dosage. No treatment related death was reported. Conclusions: Our study suggests that XELOX is a well-tolerated and convenient treatment regime. Although mild neuropathy is common in patients receiving XELOX, it causes far less disabling neuropathy than FOLFOX4 in Chinese metastatic colorectal cancer patients.

No significant financial relationships to disclose.

Treatment outcomes in anaplastic thyroid carcinoma from 1966–2006: Failure of overall survival enhancement despite four decades of progress in surgery, radiotherapy and chemoradiation

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Introduction: Anaplastic thyroid carcinoma (ATC) is a notoriously aggressive malignancy associated with a highly lethal clinical course despite therapeutic intervention. To identify factors that could suggest improved therapeutic strategies, we have analysed the clinicopathological features, treatment and outcome of all patients with ATC treated over the past four decades in our institution. Methods: Fifty patients presenting with biopsy-proven ATC to our centre between 1966 and 2006 were studied. All patients were managed with surgery, radiotherapy, chemotherapy, and/or chemoradiation. Survival was calculated using the Kaplan-Meier method. Potential factors affecting survival were compared using the log-rank test. Results: Most patients (88%) presented with a neck mass, while 17 (34%) patients also had cervical lymphadenopathy. Distant metastases at diagnosis were present in 9 (18%) of patients. Median survival was 97 days, while the 1- and 3-year survival was 14 % and 8% respectively. On univariate analysis, patients aged ≤65 years (p=0.04), undergoing surgical resection (p<0.01), receiving RT to the neck (p<0.01) and without metastatic disease on presentation (p<0.01) enjoyed longer survival. Cytotoxic chemotherapy was not associated with survival enhancement (p = 0.4). Moreover, no change in survival was evident as a function of treatment era (p = 0.5). Conclusions: ATC remains a uniformly lethal disease despite numerous technical advances in surgery, radiotherapy and chemotherapy over the last forty years. Nonetheless, our results indicate that younger patients with localized ATC be treated aggressively in a multimodality manner. Identification of signalling pathways that can be medically blocked to reduce ATC metastatic/invasive potential and enhance apoptotic sensitivity should now be the main priority for multicentre collaborative clinical research.

No significant financial relationships to disclose.

Long-term results of allogeneic bone marrow transplantation for 108 adult patients with acute lymphoblastic leukemia: favorable outcome with BMT at first remission and HLA-matched unrelated donor

We analyzed the outcome of 108 adult acute lymphoblastic leukemia patients undergoing allogeneic bone marrow transplantation (BMT). Philadelphia (Ph) chromosome occurred in 35.2% patients at diagnosis. Two-thirds of patients received allogeneic BMT in first complete remission (CR1) BMT. Salvage BMT was performed in 21 and 16 patients at second complete remission (CR2) and beyond CR2. Donors were human leukocyte antigen-identical siblings in 87 patients, and match-unrelated donors in 21 patients. Conditioning contained total body irradiation (TBI) in 92.6% patients. Overall survival (OS) for BMT at CR1 and BMT beyond CR1 were 46.2 and 20.3% at 15 years. Multivariate analyses (including age, sex, disease status, donor type, acute graft-versus-host disease (aGVHD), stem cell source, cytogenetics, grade 1/2 aGVHD and TBI-containing conditioning regimen) identified age<35, BMT at CR1 and grade 1/2 aGVHD as favorable factors for OS. Disease-free survival (DFS) for BMT at CR1 and beyond CR1 were 45.8 and 15.9% at 15 years, respectively, with BMT at CR1, age<35 and grade 1/2 aGVHD being favorable factors for DFS. Importantly, conventional adverse risk factors such as the Ph chromosome, B-cell phenotype and high leukocyte count were not associated with inferior survivals. In summary, the adverse impact of Ph chromosome, B-cell phenotype and high leukocyte count was overcome by allogeneic BMT. Matched unrelated donor transplantation appears promising.

Taurine protects from liver injury after warm ischemia in rats: the role of kupffer cells

BACKGROUND/AIMS

Warm ischemia to liver with subsequent Kupffer cell-dependent pathology is associated with many clinical conditions. Taurine prevents Kupffer cell activation and improves graft survival after experimental cold ischemia and liver transplantation. Thus this study was designed to assess its effects after warm hepatic ischemia.

METHODS

The left liver lobe of female Sprague-Dawley rats (170-210 g) underwent 60 min of warm ischemia. Animals were given either intravenous taurine or Ringer's solution 10 min prior to warm ischemia. Transaminases, histology, in vivo microscopy, intercellular adhesion molecules-1 (ICAM-1) expression, TNF-alpha and tissue hydroperoxide were compared between groups using analysis of variance (ANOVA) or ANOVA on ranks as appropriate.

RESULTS

Taurine significantly decreased transaminases and improved histologic outcome. Phagocytosis of latex beads, serum TNF-alpha levels and tissue hydroperoxide concentrations were also significantly reduced. Stickers in sinusoids and post-sinusoidal venules significantly decreased. In parallel, both leukocyte infiltration and ICAM-1 expression decreased (p < 0.05), while flow velocity of red blood cells as well as sinusoidal perfusion rate were improved (p < 0.05).

CONCLUSION

This study demonstrates that taurine blunts Kupffer cell-dependent hepatic pathology after warm ischemia in vivo via mechanisms including leukocyte-endothelial interaction, microcirculation disturbances and protection against lipid peroxidation.

Aldehyde dehydrogenase activity in leukemic blasts defines a subgroup of acute myeloid leukemia with adverse prognosis and superior NOD/SCID engrafting potential

Aldehyde dehydrogenase (ALDH) activity is used to define normal hematopoietic stem cell (HSC), but its link to leukemic stem cells (LSC) in acute myeloid leukemia (AML) is currently unknown. We hypothesize that ALDH activity in AML might be correlated with the presence of LSC. Fifty-eight bone marrow (BM) samples were collected from AML (n=43), acute lymphoblastic leukemia (ALL) (n=8) and normal cases (n=7). In 14 AML cases, a high SSC(lo)ALDH(br) cell population was identified (ALDH(+)AML) (median: 14.89%, range: 5.65-48.01%), with the majority of the SSC(lo)ALDH(br) cells coexpressing CD34(+). In another 29 cases, there was undetectable (n=23) or rare (< or =5%) (n=6) SSC(lo)ALDH(br) population (ALDH(-)AML). Among other clinicopathologic variables, ALDH(+)AML was significantly associated with adverse cytogenetic abnormalities. CD34(+) BM cells from ALDH(+)AML engrafted significantly better in NOD/SCID mice (ALDH(+)AML: injected bone 21.11+/-9.07%; uninjected bone 1.52+/-0.75% vs ALDH(-)AML: injected bone 1.77+/-1.66% (P=0.05); uninjected bone 0.23+/-0.23% (P=0.03)) with the engrafting cells showing molecular and cytogenetic aberrations identical to the original clones. Normal BM contained a small SSC(lo)ALDH(br) population (median: 2.92%, range: 0.92-5.79%), but none of the ALL cases showed this fraction. In conclusion, SSC(lo)ALDH(br) cells in ALDH(+)AML might denote primitive LSC and confer an inferior prognosis in patients.

Safety of vaccinating sibling donors with live-attenuated varicella zoster vaccine before hematopoietic stem cell transplantation

Reactivation of varicella zoster virus (VZV), clinically manifested as herpes zoster (HZ) is a common complication after hematopoietic stem cell transplantation (HSCT). The optimum prophylaxis for this disease has not been defined. In this study, we examined the effects of vaccinating donors with a live-attenuated vaccine with particular reference to their immune responses and the outcome of HSCT patients. Forty prospective HLA-matched sibling donors were vaccinated before HSCT. There were humoral immune responses in both sero-positive (P<0.01) and sero-negative (P=0.058) donors. Cellular immune response was assayed in 26 donors. Significant correlation was observed between cellular immune responses as enumerated by thymidine incorporation and interferon gamma secretion (P<0.001) and the latter was used in subsequent analyses. Significant response was observed in sero-negative (6/26) and a group of sero-positive (13/26) donors while 7/26 sero-positive donors showed no response. Thirty-four HSCT were performed. These patients have a lower, albeit insignificant, risk of HZ compared with historical controls and only 3/34 patients developed single dermatomal HZ at 6, 9 and 28 months after HSCT. No patients developed VZV-related mortality. Vaccinating donors with live-attenuated VZV vaccine was safe, but whether it confers a significant protection to the patients would require further study.

Magnetizing oxides by substituting nitrogen for oxygen

We describe a possible pathway to new magnetic materials with no conventional magnetic elements present. The substitution of nitrogen for oxygen in simple nonmagnetic oxides leads to holes in N 2p states which form local magnetic moments. Because of the very large Hund's rule coupling of Nitrogen and O 2p electrons and the rather extended spatial extent of the wave functions these materials are predicted to be ferromagnetic metals or small band gap insulators. Experimental studies support the theoretical calculations with regard to the basic electronic structure and the formation of local magnetic moments. It remains to be seen if these materials are magnetically ordered and, if so, below what temperature.

Serial analysis of JAK2 mutation in a patient who developed essential thrombocythemia after orthotopic liver transplantation

A 52-year-old man developed essential thrombocythemia (ET) with JAK2 V617F mutation after orthotopic liver transplantation (OLT). Retrospective analysis showed that, despite a low platelet count, the JAK2 mutation was already found at presentation 14 months before OLT. The high platelet count that would have been typical of ET might be masked by the cirrhosis-related hypersplenism. Thrombocythemia became obvious after OLT. The patient subsequently developed blastic transformation 12 months afterward, a process probably accelerated by the immunosuppression required for the OLT.

A prospective study of respiratory ciliary structure and function after stem cell transplantation

We prospectively investigated the morphological and ciliary function abnormalities in 19 consecutive Chinese patients undergoing hemopoietic stem cell transplantation (HSCT) and studied their relationship with pulmonary complications. The percentage of structural ciliary abnormalities preceding HSCT was comparable to normal controls, but increased up to 1-year post-HSCT. However, the abnormalities did not correlate with ciliary or pulmonary function. Ciliary beat frequency (CBF) for patients undergoing autologous and allogeneic SCT was lower than that of matched controls, with a further decline at one year. There was, however, no significant change in pulmonary function for the whole cohort. There was considerable variation in CBF and ciliary abnormalities in all cases during 3-month interval assessments. Regular ciliary assessment did not predict the only two patients who eventually suffered from bronchiolitis obliterans (BO). We conclude that structural and functional ciliary abnormalities are common in recipients of HSCT, and predict post-HSCT deterioration. However, there is no evidence to show that CBF monitoring may be of prospective benefit.

Frequent DAP kinase but not p14 or Apaf-1 hypermethylation in B-cell chronic lymphocytic leukemia

Dysregulation of apoptosis, and thus the p14/DAP kinase/HDM2/p53/Apaf-1 pathway, is potentially important in carcinogenesis. Chronic lymphocytic leukemia (CLL), uncommon in the Chinese, is a disease characterized by impaired apoptosis, of the neoplastic lymphocytes. Hypermethylation of p14, DAP kinase and Apaf-1 was studied by methylation-specific polymerase chain reaction (MSP) with primers for methylated (M-MSP) and unmethylated (U-MSP) alleles in 50 diagnostic marrow samples from patients with CLL. Chinese CLL patients had an indolent course similar to Caucasians with median overall survival (OS) of 96 months, which was adversely affected by advanced Rai stage (projected 5-year OS = 72% and 39% for Rai < or = 2 and Rai > 2; P = 0.01). DAP kinase was methylated in 18 (36%) patients while p14 and Apaf-1 were completely unmethylated in all the primary CLL samples. There was no correlation between DAP kinase hypermethylation and age, sex, poor-risk karyotype, lymphocyte count and Rai stage at diagnosis. Projected OS for patients with and without DAP kinase hypermethylation were 59 and 57% (P = 0.91). DAP kinase, but not p14 and Apaf-1, of the DAP kinase/p14/HDM2/p53/Apaf-1 pathway is frequently hypermethylated in CLL, but not of prognostic significance. Moreover Chinese patients with CLL share a similarly indolent clinical course, and this is the first comprehensive study on p14, DAP kinase and Apaf-1 hypermethylation in CLL.

Methylation of INK4 and CIP/KIP families of cyclin-dependent kinase inhibitor in chronic lymphocytic leukaemia in Chinese patients

BACKGROUND

INK4 (p15, p16, p18 and p19) and CIP/KIP (p21, p27 and p57) are two families of cyclin-dependent kinase inhibitors (CKI) targeting CDK4/6 and CDK2, respectively.

AIM

To study the role of methylation in the inactivation of CKI in chronic lymphocytic leukaemia (CLL).

MATERIALS AND METHODS

Methylation-specific polymerase chain reaction was carried out on DNA obtained from the bone marrow of 56 newly diagnosed patients with CLL.

RESULTS

Similar demographic features and clinical outcome were observed in our patients when compared with Caucasian patients, including an indolent clinical course (10-year overall survival 51%) and advanced Rai stage (p = 0.006), and a high-risk karyotype such as trisomy 12 and complex aberrations (p = 0.03). In the INK4 family, methylation in p15 and p16 occurred in 20 (35.7%) and 8 (14.3%) patients, respectively. In all, 5 (8.9%) CLL samples harboured concurrent methylation of both p15 and p16. Apart from an association of p16 methylation with higher presenting leucocyte count (64.5 x 10(9)/l in methylated p16 and 16.0 x 10(9)/l in unmethylated p16 patients; p = 0.016), there was no association between p15 and p16 methylation and age, sex and Rai stage. No difference was observed in the overall survival for patients with and without p15 and p16 methylation. By contrast, p18 and Rb were unmethylated in all samples. In the CIP/KIP family, apart from infrequent methylation of p57 in 4 (7.1%) patients, methylation of p21 and p27 was uniformly absent.

CONCLUSION

p15 and, less frequently, p16 of the INK4 family of CKI, instead of the CIP or KIP family, were targeted by methylation in CLL. p16 methylation was associated with a higher lymphocyte count at presentation. This is the first comprehensive study of the epigenetic dysregulation of the INK4 and CIP/KIP families of CKI in Chinese patients with CLL.

Infrequent Wnt inhibitory factor-1 (Wif-1) methylation in chronic lymphocytic leukemia

The Wnt pathway has been shown recently, to be activated in patients with chronic lymphocytic leukemia (CLL). This is the first study to examine the role of Wnt inhibitory factor-1 (Wif-1) methylation in the pathogenesis of haematolymphoid malignancies. Wif-1, a putative tumor suppressor, is a soluble negative regulator of the Wnt pathway activated in CLL. We studied the role of methylation of Wif-1 in 43 Chinese patients with CLL. At diagnosis, Wif-1 methylation was detected in 5/43 (11.6%) CLL marrow samples. Wif-1 methylation occurred more frequently in patients with advanced age (p = 0.059) but there was no correlation between Wif-1 methylation and sex, lymphocyte count and Rai stage at diagnosis. In conclusion, Wif-1 is infrequently methylated in CLL. Other factors leading to activation of the Wnt pathway warrant further study.

Long-term donor health and its relationship with outcome of allogeneic hematopoietic stem cell transplantation

Data on long-term follow-up of donors for hematopoietic stem cell transplantation (HSCT) are limited. Donors of 612 adult allogeneic HSCT were studied, at a median of 81 (14-181) months post-HSC donation. Nine donors had severe health problems. Five donors died from aggressive malignancies or terminal illness, at a median of 41 (16-57) months post-donation. Notably, all their recipients had leukemic relapses. In contrast, donors of recipients in remission were all living. This observation might be due to an inherent depressed immunosurveillance in the donors, or selection of donors with suboptimal health for desperate patients with poor risks pre-HSCT.

Hepatitis B reactivation after withdrawal of pre-emptive lamivudine in patients with haematological malignancy on completion of cytotoxic chemotherapy

BACKGROUND

The hepatic outcome of hepatitis B surface antigen (HBsAg) positive patients undergoing chemotherapy after withdrawal of pre-emptive lamivudine is unknown.

AIMS

To examine the occurrence of hepatitis B virus (HBV) reactivation after withdrawal of pre-emptive lamivudine.

METHODS

Pre-emptive lamivudine was started one week before initiation of chemotherapy in 46 consecutive HBsAg positive patients and continued for the entire duration of chemotherapy. Pre-emptive lamivudine was stopped at a median 3.1 (range 3.0-3.4) months after completion of chemotherapy. Patients were longitudinally followed up after withdrawal of pre-emptive lamivudine.

RESULTS

Median time of follow up after withdrawal of lamivudine was 25.7 (range 5.7-75.7) months. Eleven of the 46 patients (23.9%) developed HBV reactivation after withdrawal of pre-emptive lamivudine. Eight of the 16 patients with high pre-chemotherapy HBV DNA (> or =10(4) copies/ml) compared with three of the 30 patients with low pre-chemotherapy HBV DNA (<10(4) copies/ml) developed HBV reactivation (50.0% v 10.0%, respectively; p<0.001). Hepatitis B e antigen positive patients were also more likely to develop HBV reactivation (5/11 (45.5%) v 6/35 (17.1%), respectively; p = 0.041). A high pre-chemotherapy HBV DNA (> or =10(4) copies/ml) was the most important risk factor for HBV reactivation after withdrawal of pre-emptive lamivudine on Cox proportional hazards analysis (relative risk 16.13, (95% confidence interval 2.99-87.01; p = 0.001).

CONCLUSIONS

HBV reactivation is more likely to occur in patients with high pre-chemotherapy HBV DNA after withdrawal of pre-emptive lamivudine. A more prolonged course of antiviral therapy may be necessary in these patients after completion of chemotherapy in order to reduce post-chemotherapy HBV reactivation.