HLA associations, microsatellite instability and epigenetic changes in thyroid lymphoma in Chinese

In Chinese, autoimmune thyroid disease (AITD) is very common but lymphoma of the thyroid is a rare disease. Southern Chinese AITD is common in females and is strongly linked to the HLA haplotype A2B46DR9. We studied the HLA association, aberration p15, p16 and p73 promoter methylation and microsatellite instability in Chinese primary thyroid lymphoma patients to elucidate their relationship with AITD and the relationship between thyroid diffuse large cell lymphoma (DLCL) and marginal zone lymphomas (MZL). Despite a female preponderance (8:1) and the finding of cases with histological and immunological evidence of AITD, a significant HLA association was not found. MSI was absent, but aberrant promoter methylation was found in both thyroid MZL and DLCL and p73 methylation was unexpectedly common.

Tumor necrosis factor alpha promoter polymorphism and the risk of chronic lymphocytic leukemia and myeloma in the Chinese population

The -308 GA promoter polymorphism of tumor necrosis factor alpha (TNFalpha) has been reported to be associated with an increased risk of lymphoid malignancies in Caucasians. We studied the incidence and prognostic significance of this polymorphism in Chinese patients with plasma cell myeloma (PCM), chronic lymphocytic leukemia (CLL) and lymphomas. Despite a far lower incidence of PCM and CLL in the Chinese population compared with Caucasians, the rates of TNFalpha-308A were similar to those in Caucasians, both in the study and control populations. Similarly, there was no increased rate of TNFalpha-308A in all the lymphomas studied, irrespective of lineage. However, TNFalpha-308A is significantly associated with female CLL cases and confers a strong negative prognostic impact for Chinese CLL. These argue for a possible biological role for increased TNFalpha production in CLL progression in low-risk individuals.

[Rosiglitazone and all-trans retinoic acid inhibit human myeloma cell proliferation via apoptosis signaling pathway modulation]

OBJECTIVE

To investigate the effects of artificial ligand of peroxisome proliferators activated receptors (PPARs), rosiglitazone (RGZ) and all trans-retinoic acid (ATRA) on human myeloma cell line growth in vitro and in vivo.

METHODS

U266 and RPMI 8226 cells were treated with different concentration of RGZ in the presence or absence of ATRA and the results were studied by 3H-TdR thymidine incorporation (for cells proliferation), Annexin V-PI staining and caspase-3 activity assay (for cells apoptosis), RT-PCR (for FLIP, XIAP and survivin mRNA expression), and tumor formation test in BALB/c nude mice.

RESULTS

Exposure to RGZ induced proliferation inhibition in a dose-dependent manner in both U266 (r = 0.991, P < 0.01) and RPMI 8226 cells (r = 0.961, P < 0.01). A combination of RGZ with ATRA could enhance the inhibition effect (P < 0.001 in U266, P < 0.01 in RPMI8226). 10 micromol/L of RGZ induced apoptosis of (9.8 +/- 1.7)% in U266 cells and (10.7 +/- 3.3)% in RPMI8226 cells, in a time and dose dependent manner and combined with ATRA intensified the apoptosis induction effects (P < 0.01 in both cell lines). The FLIP, XIAP and survivin mRNAs were expressed in both cell lines and their levels decreased significantly after cultured with RGZ. The addition of RGZ + ATRA in the culture further decreased the levels. Caspase-3 activity increased substantially with the increase of RGZ concentration and the addition of RGZ + ATRA in the culture medium showed similar synergism effect on caspase-3 activation (P < 0.01). The xenograft of U266 cells in BALB/c nude mice were inhibited by RGZ and so did more by the combination of RGZ and ATRA (P < 0.01).

CONCLUSION

The down-regulation of FLIP, XIAP and Survivin induced by RGZ can activate caspase-3, whereby induced apoptosis and proliferation inhibition in myeloma cells. ATRA can enhance these effects of RGZ.

Organ-specific hemosiderosis and functional correlation in Chinese patients with thalassemia intermedia and hemoglobin H disease

We performed MRI assessment in 37 adult Chinese patients with thalassemia intermedia and hemoglobin H disease. Despite abnormal ferritin and liver T2*, only 5% of patients had cardiac hemosiderosis. The two patients with reduced ejection fraction had normal cardiac T2*. Half of the cases showed pituitary and pancreatic iron loading. Subclinical endocrine abnormalities (HOMA, insulin growth factor) showed correlation with pancreatic, pituitary, and cardiac MRI values. Prospective data with serial functional and imaging monitoring is needed to verify the utility for chelation to improve cardiac and endocrine function in this group of patients.

Inhomogeneous magnetic-field response of YBa2Cu3Oy and La2-xSrxCuO4 persisting above the bulk superconducting transition temperature

We report that in YBa2Cu3Oy and La2-xSrxCuO4 there is a spatially inhomogeneous response to the magnetic field for temperatures T extending well above the bulk-superconducting transition temperature Tc. An inhomogeneous magnetic response is observed above Tc even in ortho-II YBa2Cu3O6.50, which has highly ordered doping. The degree of the field inhomogeneity above Tc tracks the hole-doping dependences of both Tc and the density of the superconducting carriers below Tc, and therefore is apparently coupled to superconductivity.

Epigenetic dysregulation of the Wnt signalling pathway in chronic lymphocytic leukaemia

Background:

Wnt signalling has recently been implicated in the pathogenesis of cancer.

Methods:

This study investigated the activity of Wnt signalling in peripheral blood chronic lymphocytic leukaemia (CLL) lymphocytes, and the methylation status of seven soluble Wnt antagonist genes, including WIF1, DKK3, APC, SFRP1, SFRP2, SFRP4 and SFRP5, by using methylation-specific PCR in the peripheral blood CLL lymphocytes and bone marrow samples of patients with CLL at diagnosis.

Results:

In the peripheral blood CLL lymphocytes, constitutive activation of Wnt signalling was detected, associated with hypermethylation of the soluble Wnt inhibitor genes. In the diagnostic CLL marrow samples, methylation of the seven genes was detected in up to 36.4% of samples. Moreover, 23 (52.3%) patients had methylation of at least one of the seven genes, of whom 14 (60.8%) had methylation of two or more Wnt inhibitor genes. Apart from an association of advanced age with DKK3 methylation, there was no association of gene hypermethylation with either clinical characteristics (including age, gender, lymphocyte count at diagnosis, Rai stage and poor-risk karyotype) or survival.

Conclusion:

Wnt signalling is constitutively activated in CLL B lymphocytes in association with methylation of multiple soluble Wnt antagonist genes. Methylation of these soluble Wnt antagonist genes, occasionally multiple genes, in primary CLL marrow samples suggests an important role in CLL pathogenesis. Moreover, this study underscored the importance of studying methylation of a panel of, but not individual, genes regulating a cellular pathway.

Review article: current management of metastatic colorectal cancer - the evolving impact of targeted drug therapies

BACKGROUND

The field of colorectal cancer chemotherapy has been transformed by the advent of molecule-specific drugs. Combined use of such drugs enhances tumour response rates, but controlled data quantifying the relative efficacy and cost-effectiveness of different drug combinations on overall survival remain scarce.

AIM

To conduct an overview of published clinical trials in advanced colorectal cancer, with the objective of framing provisional approaches to current management.

METHODS

An NCBI/PubMed search was performed using the strings, 'colorectal cancer' ('metastatic' or 'advanced' or 'palliative') and ('chemotherapy' or 'drug therapy' or 'targeted' or 'target-specific' or 'molecularly-targeted').

RESULTS

Combinations of target-specific drugs (with or without the DNA-alkylating agent oxaliplatin) have substantially enhanced colorectal cancer time to progression over the last decade and have also expedited surgical resection of liver metastases. Disease-free survival, overall survival and quality of life are favourably influenced.

CONCLUSIONS

Target-specific drugs improve palliative efficacy in the setting of advanced colorectal cancer. However, key issues persist as to the cost-effectiveness of these newer drug treatments, and further controlled trials are needed to resolve this important debate.

de Haas-van Alphen oscillations in the underdoped high-temperature superconductor YBa2Cu3O6.5

The de Haas-van Alphen effect was observed in the underdoped cuprate YBa2Cu3O6.5 via a torque technique in pulsed magnetic fields up to 59 T. Above a field of approximately 30 T the magnetization exhibits clear quantum oscillations with a single frequency of 540 T and a cyclotron mass of 1.76 times the free electron mass, in excellent agreement with previously observed Shubnikov-de Haas oscillations. The oscillations obey the standard Lifshitz-Kosevich formula of Fermi-liquid theory. This thermodynamic observation of quantum oscillations confirms the existence of a well-defined, closed, and coherent, Fermi surface in the pseudogap phase of cuprates.

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.

Superfluid density in a highly underdoped YBa_{2}Cu_{3}O_{6+y} superconductor

The superfluid density rho_{s}(T) identical with1/lambda;{2}(T) has been measured at 2.64 GHz in highly underdoped YBa_{2}Cu_{3}O_{6+y}, at 37 dopings with T_{c} between 3 and 17 K. Within limits set by the transition width DeltaT_{c} approximately 0.4 K, rho_{s}(T) shows no evidence of critical fluctuations as T-->T_{c}, with a mean-field-like transition and no indication of vortex unbinding. Instead, we propose that rho_{s} displays the behavior expected for a quantum phase transition in the (3+1)-dimensional XY universality class, with rho_{s0} proportional, variant(p-p_{c}), T_{c} proportional, variant(p-p_{c});{1/2}, and rho_{s}(T) proportional, variant(T_{c}-T);{1} as T-->T_{c}.

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.

Quantum oscillations and the Fermi surface in an underdoped high-Tc superconductor

Despite twenty years of research, the phase diagram of high-transition-temperature superconductors remains enigmatic. A central issue is the origin of the differences in the physical properties of these copper oxides doped to opposite sides of the superconducting region. In the overdoped regime, the material behaves as a reasonably conventional metal, with a large Fermi surface. The underdoped regime, however, is highly anomalous and appears to have no coherent Fermi surface, but only disconnected 'Fermi arcs'. The fundamental question, then, is whether underdoped copper oxides have a Fermi surface, and if so, whether it is topologically different from that seen in the overdoped regime. Here we report the observation of quantum oscillations in the electrical resistance of the oxygen-ordered copper oxide YBa2Cu3O6.5, establishing the existence of a well-defined Fermi surface in the ground state of underdoped copper oxides, once superconductivity is suppressed by a magnetic field. The low oscillation frequency reveals a Fermi surface made of small pockets, in contrast to the large cylinder characteristic of the overdoped regime. Two possible interpretations are discussed: either a small pocket is part of the band structure specific to YBa2Cu3O6.5 or small pockets arise from a topological change at a critical point in the phase diagram. Our understanding of high-transition-temperature (high-T(c)) superconductors will depend critically on which of these two interpretations proves to be correct.

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.