Alloimmunization among patients with transfusion-dependent thalassemia in Taiwan

The development of erythrocyte alloantibodies complicates transfusion therapy in patients with thalassemia. However, no data are available on the frequency of erythrocyte alloimmunization in patients with transfusion-dependent thalassemia in Taiwan. We analysed the clinical and transfusion records of 30 individuals (15 females and 15 males; mean age, 20 years; range, 4-31 years) with thalassemia who had regular transfusions for periods ranging from 0.5 to 20 years. Of the 30 patients, 28 who had beta-thalassemia major and two who had Hb H disease (alpha thalassemia), 11 (37%) were found to carry alloantibodies. All alloantibodies were clinically significant specificities, including four cases of anti-E, two of anti-E + c, two of anti-'Mi(a)', one of anti-'Mi(a)' + E, one of anti-D and one of anti-S. Alloimmunization to erythrocyte antigens is a frequent complication in transfusion-dependent thalassemia.

A novel HLA-B allele, B*5612, identified by sequence-based typing method

HLA-B*5612, found in Taiwan using sequence-based typing method, was identical to HLA-B*5502 in exon 2 but differed in exon 3 by 10 nucleotide substitutions at positions 353-420 leading to five amino acid change at codon 94, 95, 97, 103 and 116. As this sequence motif was not found in the Asian population, it is likely that HLA-B*5612 is the product of a complex mechanism of implying a dual gene conversion event.

A high yield robotic synthesis of 9-(4-[18F]-fluoro-3-hydroxymethylbutyl)guanine ([18F]FHBG) and 9-[3-[18F]fluoro-1-hydroxy-2-propoxy)methyl]guanine([18F] FHPG) for gene expression imaging

The aim of this study was to develop an automated synthesis of 9-(4-[(18)F]-fluoro-3-hydroxymethylbutyl)guanine ([(18)F]FHBG) and 9-[(3-[(18)F]fluoro-1-hydroxy-2-propoxy)methyl]guanine ([(18)F]FHPG) using a Scanditronix Anatech RB III robotic system. [(18)F]HF was produced via (18)O(p, n)(18)F using a Scanditronix MC17F cyclotron. On average, a typical run produced [(18)F]FHBG and [(18)F]FHPG with an uncorrected radiochemical yield of 19% and 16%, respectively, at end of synthesis (EOS) from irradiation of 95% enriched [(18)O]water. The total synthesis time was 80 min. The retention time of [(18)F]FHBG and [(18)F]FHPG (the radio-peak) was 3.9 and 4.0 min, respectively, which was consistent with the [(19)F]FHBG and [(19)F]FHPG ultraviolet peak. The radiochemical purity was greater than 97%. A robotic, automated method for [(18)F]FHBG and [(18)F]FHPG radiosynthesis is therefore feasible. The radiation burden for the operator can be reduced as much as possible. Sufficient radioactivities of [(18)F]FHBG and [(18)F]FHPG could be obtained for non-invasive monitoring the expression of transfected gene in vivo with positron emission tomography (PET).

Association between diabetes and depression: Sex and age differences

OBJECTIVE

To examine the association between diabetes and the prevalence of depression in different sex and age groups by analysing the cross-sectional data from the National Population Health Survey, conducted in Canada in 1996-1997.

STUDY DESIGN

A total of 53072 people aged 20-64 years were included in the analysis. Depression was defined as depression scale 5, based on the Composite International Diagnostic Interview Short-Form (CIDI-SF). Respondents who answered the following question affirmatively were considered to have diabetes: 'do you have diabetes diagnosed by a health professional?'.

METHODS

A multiple logistic regression model was used to adjust for potential confounding effects, and a bootstrap procedure was used to take sampling weights and design effects into account.

RESULTS

The prevalence of diabetes was much higher in people aged 40-64 years than in people aged 20-39 years (men: 4.7% vs. 0.5%; women: 3.5% vs. 0.8%, respectively). In contrast, people aged 20-39 years had a slightly higher prevalence of depression than those aged 40-64 years (men: 3.1% vs. 2.9%; women: 6.6% vs. 5.4%, respectively). Diabetes was significantly associated with depression in women aged 20-39 years (odds ratio [OR]=2.52, 95% confidence interval [CI]=1.19, 5.32), but not in women aged 40-64 years (OR=1.62, and 95% CI=0.65, 4.06). The association was not significant in both age groups in men, but it tended to be stronger in the younger age group.

CONCLUSIONS

The data suggest that diabetes is significantly associated with depression, particularly in young adults.

Inhibition of Listeria innocua in hummus by a combination of nisin and citric acid

The effect of nisin or citric acid or combinations of these two inhibitors on the inactivation of a cocktail of three Listeria innocua strains was investigated in a model brain heart infusion (BHI) broth and hummus (chickpea dip). In BHI broth, citric acid had a limited ability to inhibit L. innocua growth. Nisin initially reduced L. innocua concentrations by about 3 log cycles; however, L. innocua reached concentrations similar to those of the control after 5 days at 22 degrees C. In combination, the effects of 500 IU/ml nisin and 0.2% citric acid were synergistic and resulted in complete elimination of L. innocua in the BHI broth. The inhibition of L. innocua by nisin (500 or 1,000 IU/g), citric acid (0.1, 0.2, or 0.3%), or their combinations also was evaluated in hummus. Citric acid alone did not affect L. innocua growth or the aerobic bacterial plate count. A combination of 1,000 IU/g nisin and 0.3% citric acid was somewhat effective (approximately 1.5-log reduction) in controlling the concentration of L. innocua and the aerobic plate count for up to 6 days. This combination also may be useful, in addition to proper hygienic practices, for minimizing the growth of the pathogen Listeria monocytogenes in hummus.

DNA copy number gains in head and neck squamous cell carcinoma

Gene amplification, a common mechanism for oncogene activation in cancer, has been used as a tag for the identification of novel oncogenes. DNA amplification is frequently observed in head and neck squamous cell carcinoma (HNSCC) and potential oncogenes have already been reported. We applied restriction landmark genome scanning (RLGS) to study gene amplifications and low-level copy number changes in HNSCC in order to locate previously uncharacterized regions with copy number gains in primary tumor samples. A total of 63 enhanced RLGS fragments, indicative of DNA copy number changes, including gains of single alleles, were scored. Enhanced sequences were identified from 33 different chromosomal regions including those previously reported (e.g. 3q26.3 and 11q13.3) as well as novel regions (e.g. 3q29, 8q13.1, 8q22.3, 9q32, 10q24.32, 14q32.32, 17q25.1 and 20q13.33). Furthermore, our data suggest that amplicons 11q13.3 and 3q26.3-q29 may be divided into possibly two and three independent amplicons, respectively, an observation supported by published microarray expression data.

Creatine in Huntington disease is safe, tolerable, bioavailable in brain and reduces serum 8OH2'dG

In a randomized, double-blind, placebo-controlled study in 64 subjects with Huntington disease (HD), 8 g/day of creatine administered for 16 weeks was well tolerated and safe. Serum and brain creatine concentrations increased in the creatine-treated group and returned to baseline after washout. Serum 8-hydroxy-2'-deoxyguanosine (8OH2'dG) levels, an indicator of oxidative injury to DNA, were markedly elevated in HD and reduced by creatine treatment.

Soluble, dimeric HLA DR4-peptide chimeras: an approach for detection and immunoregulation of human type-1 diabetes

Still there are no effective methods to predict or cure type 1 diabetes (T1D) in humans. Soluble, dimeric MHC class II-peptide (DEF) chimeras have potential for both early diagnosis and immunospecific therapy. DEF chimeras prevent and reverse diabetes in mice by stimulating antigen-specific type 1 T regulatory cell (Tr1)-like cells. We also showed that diabetes could be predicted by changes in the phenotype of autoreactive CD4 T cells in peripheral blood. Herein, we demonstrated that human DEF (HLA-DR*0401/Fcgamma1) chimeras expressing peptides of beta-cell antigens stimulate Tr1-like cells in blood of patients with T1D, non-diabetic relatives, and controls. Furthermore, the specific and stable binding of DEF chimeras to cognate TCR and CD4 coreceptor allowed quantification and phenotyping of autoreactive CD4 T cells in non-stimulated blood by FACS. Our results indicate that (1) autoreactive CD4 T cells to GAD65 autoantigen are commonly present in humans expressing diabetes-susceptible HLA-DR*0401 molecules; (2) these autoreactive T cells undergo avidity maturation upon encountering the self antigen early in life; (3) the disease is associated with an imbalance between autoreactive CD4+CD25+ and CD4+CD69+ T cells specific for GAD65. Based on this, we propose a model to explain the kinetics of autoreactive CD4 T cells in blood during the natural history of T1D.

Treatment of volatile organic compounds from polyurethane and epoxy manufacture by a trickle-bed air biofilter

The objective of this study was to evaluate the performance of a trickle-bed air biofilter (TBAB) for the removal of volatile organic compound (VOC) produced during polyurethane (PU) and epoxy manufacture. The major VOCs emitted are ethyl acetate (EA) for PU and EA and xylene for epoxy production. For the treatment of VOCs emitted during PU production, the employed coal carbon appears to be efficient as a VOC concentration buffer in the biofiltration of waste gases. Based on the results of EA and total hydrocarbon (THC) removal, it was concluded that the TBAB is suitable for controlling VOC emission during PU manufacture. For the treatment of VOCs emitted during epoxy production, it was found that the performance of the TBAB is relatively poor due to the lack of VOC sources. However, this problem could be easily solved by mixing the VOCs emitted during PU and epoxy manufacture.

MHC Class II–Mediated Apoptosis by a Nonpolymorphic MHC Class II Peptide Proceeds by Activation of Protein Kinase C

It was demonstrated previously that a peptide derived from a conserved region of MHC class II, HLA-DQA1, inhibits proliferation of allogeneic T cells in vitro. Administration of HLA-DQA1 in conjunction with allogeneic cells at the time of priming or at the time of rechallenge prevented the development of the delayed type hypersensitivity response in vivo. The immunomodulatory effects of HLA-DQA1 were associated with the induction of apoptosis in B cells, macrophages, and dendritic cells via a caspase-independent pathway. This study investigated the binding site and mechanism that mediates cell death induced by HLA-DQA1. It was demonstrated that HLA-DQA1 binds to MHC class II on the cell surface, causing MHC class II signaling, initiation of protein kinase C signaling, and mitochondrial membrane depolarization with resultant apoptosis. The data indicate that HLA-DQA1 binds to MHC class II outside the groove, in a manner similar to superantigen. These results suggest that HLA-DQA1 is a novel immunotherapy that may provide an effective means of targeting professional antigen-presenting cells, in particular B cells.

Sequencing drug response with HapMap

The information about how DNA sequence varies across the human genome is crucial for unravelling the genetic basis of drug response. A haplotype map, or HapMap, intended to reveal such a variation pattern, has been recently developed by the International HapMap Consortium. Here, we present a conceptual model for directly characterizing specific DNA sequence variants that are responsible for drug response based on the haplotype structure provided by HapMap. Our model is developed in the maximum likelihood context, incorporated by clinically meaningful mathematical functions that model drug response and implemented with the EM algorithm. Our model is employed to a pharmacogenetic study of cardiovascular disease with 107 patients. We found that the haplotype constituted by allele Gly16 (G) at codon 16 and allele Glu27 (G) at codon 27 genotyped within the beta2AR candidate gene exhibits a different effect on heart rate curve from the rest haplotypes. Parents with the diplotype consisting of two copies of haplotype GG are more sensitive in heart rate to increasing dosages of dobutamine than those with other haplotypes. This model provides a powerful tool for elucidating the genetic variants of drug response and ultimately designing personalized medications based on each patient's genetic constitution.

A newly identified HLA-C allele: Cw*1210, and confirmation of HLA-Cw*080102

HLA-Cw*1210 and -Cw*080102 were identified in Taiwan populations using reverse-line SSO typing method. Sequencing showed that HLA-Cw*1210 and -Cw*120201/02 were identical at exon 2 but differed at exon 3 with three nucleotide substitutions at codons 99 and 105 and an amino acid change from tyrosine to phenylalanine at codon 99. Also, allele HLA-Cw*080102 differed from HLA-Cw*080101 in exon 3 by a single synonymous nucleotide transition at codon 99. HLA-Cw*080102 was found only in the Puyuma indigenous tribe of Taiwan and had a frequency of 5%. Interestingly, nucleotide substitutions of HLA-Cw*1210 and -Cw*080102 were located in a noticeably heterogeneous region of the 5' end of exon 3, where similar substitution motifs are frequently found in other HLA-C alleles, therefore suggesting preferential gene conversion in this region.

Neonatal alloimmune thrombocytopenia due to an antibody against a labile component of human platelet antigen-3b (Bak b)

We report the second case of neonatal alloimmune thrombocytopenia due to anti-human platelet antigen (HPA)-3b (Bak(b)) antibody. The infant was severely affected with intracranial haemorrhage. Most importantly, we were able to detect this antibody only by using fresh, unfixed platelets as antigen. This antibody was detectable neither by conventional mixed passive haemagglutination, platelet immunofluorescence test using fixed platelets, nor by monoclonal antigen immobilization of platelet antigen assay using solubilized platelets. We assume that this antibody reacts only with fresh platelets and that the antigen is a labile component of HPA-3b (Bak(b)).