The importance of evaluating specific myeloid malignancies in epidemiological studies of environmental carcinogens

INTRODUCTION

Although myelodysplastic syndrome (MDS), acute myeloid leukemia (AML), myeloproliferative neoplasms (MPN) - including chronic myeloid leukemia (CML) - and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are largely clinically distinct myeloid malignancies, epidemiological studies rarely examine them separately and often combine them with lymphoid malignancies, limiting possible etiological interpretations for specific myeloid malignancies.

METHODS

We systematically evaluated the epidemiological literature on the four chemical agents (1,3-butadiene, formaldehyde, benzene, and tobacco smoking, excluding pharmaceutical, microbial and radioactive agents, and pesticides) classified by the International Agency for Research on Cancer as having sufficient epidemiological evidence to conclude that each causes "myeloid malignancies." Literature searches of IARC Monographs and PubMed identified 85 studies that we critically assessed, and for appropriate subsets, summarized results using meta-analysis.

RESULTS

Only two epidemiological studies on 1,3-butadiene were identified, but reported findings were inadequate to evaluate specific myeloid malignancies. Studies on formaldehyde reported results for AML and CML - and not for MDS or MPN - but reported no increased risks. For benzene, several specific myeloid malignancies were evaluated, with consistent associations reported with AML and MDS and mixed results for CML. Studies of tobacco smoking examined all major myeloid malignancies, demonstrating consistent relationships with AML, MDS and MPN, but not with CML.

CONCLUSIONS

Surprisingly few epidemiological studies present results for specific myeloid malignancies, and those identified were inconsistent across studies of the same exposure, as well as across chemical agents. This exercise illustrates that even for agents classified as having sufficient evidence of causing "myeloid malignancies," the epidemiological evidence for specific myeloid malignancies is generally limited and inconsistent. Future epidemiological studies should report findings for the specific myeloid malignancies, as combining them post hoc - where appropriate - always remains possible, whereas disaggregation may not. Furthermore, combining results across possibly discrete diseases reduces the chances of identifying important malignancy-specific causal associations.

First-principles computation of electron transfer and reaction rate at a perovskite cathode for hydrogen production

The focus of this research is on the electron transfer and its reaction rate at the perovskite cathode of a photoelectrochemical cell for hydrogen production. By employing the density functional theory (DFT), the electron density, projected density of states (PDOS), electron distribution and electron transfer path between [Fe-Fe] hydrogenase and the perovskite cathode can be obtained. Simulation results show that the perovskite cathode is better than traditional cathodes for hydrogen production. Before transmission to the [Fe-Fe] hydrogenase, electron clouds mainly aggregate at the periphery of amine molecules. Simulations also show that the key to hydrogen production at the perovskite structure lies in the organic molecules. Electrons are transferred to the hydrocarbon structural chain before reaching the Fe atoms. The Rice, Ramsperger, Kassel and Marcus (RRKM) theory was used to predict the reaction rates at different temperatures. It was found that the reaction rates are in good agreement with the experimental results. This research provides more physical insight into the electron transfer mechanism during the hydrogen production process.

Attitudes about Organ and Tissue Donation among the General Public and Blood Donors in Hong Kong

Context

The cadaveric organ and tissue donation rate in Hong Kong is not satisfactory; 1 million blood donors are registered and more than 300 000 are active. However, the current attitudes toward organ and tissue donation in the general public and blood donors of Hong Kong are unknown.

Methods

Random general public (n = 1018) and blood donors (n = 1227) of Chinese origin, with age ranging from 16 to 60 years, were interviewed using a standard verified questionnaire that examines attitudes and knowledge of organ and tissue donation.

Results

The mean age of the general public and blood donors were 32.6 and 28.9 years, respectively. Of the general public, 44.4% were men and among blood donors, 60% were men. About 56% of both groups thought that organ donation is an obligation of citizens. Blood donors were more aware than the general public about the types of organs that can be donated. When compared with the general public, a significantly higher percentage of blood donors were willing to donate their organs (81% vs 53%), had heard about organ donation cards (98.3% vs 89.5%), and had signed the cards (49.9% vs 22.6%). About 70% of both groups who had signed a card were carrying it. Thirty-nine percent of the general public and 17% of blood donors had not decided whether they would donate. For blood donors, 49.7% were willing to donate their relatives' organs, compared with 41.8% of the general public. Most individuals in both groups would not object to their relatives' decision to donate. About two thirds of individuals in both groups disagreed with the concept of an opt-out law, though only 20% of the general public and 14.4% of blood donors would refuse donation if an opt-out law were in practice.

Conclusions

This study shows that blood donors have better knowledge of organ donation and are more willing to donate their organs and sign an organ donation card than the general public. However, a substantial proportion of blood donors have not signed a donor card. It would be useful to design promotion programs to facilitate blood donors' participation in organ donation.

Loss of speech after living-related donor liver transplantation: detection of the lesion by diffusion tensor image

INTRODUCTION

Loss of speech after living-related liver transplantation is uncommon. Either immunosuppressive agents, related sequelae, or a neurological event may cause it.

CASE REPORT

A 46-year-old man developed dysarthria and dysphagia on the 10th day after living-related donor liver transplantation for alcoholic cirrhosis with Child-Pugh class C. Brain magnetic resonance images and electroencephalograms could not detect any lesion, but the diffusion tensor image showed a subacute lacunar infarction at right midbrain. The patient's speech improved 1 month after rehabilitation.

CONCLUSIONS

Some unexpected neurological events, such as loss of speech, may occur after liver transplantation. The differential diagnosis becomes very important before active treatment. Magnetic resonance imaging supplemented with diffusion tensor imaging is an effective imaging study in establishing the diagnosis.

A study of the predonation hemoglobin and iron status among Hong Kong Chinese blood donors

BACKGROUND

Predonation hemoglobin (PDH) is used to safeguard donors' welfare, and low hemoglobin (Hb) is known to be the most frequent reason for donor deferral. A study was initiated to assess the PDH and iron status of blood donors in Hong Kong.

STUDY DESIGN AND METHODS

This observational study was designed with four groups of whole blood donors invited (group 1-eligible first time donors, group 2-eligible repeat donors with zero or one donation in preceding 12 months, group 3-eligible repeat donors with at least two donations in preceding 12 months, group 4-repeat donors being deferred for low PDH). Predonation blood samples were obtained for blood counts and iron status. Mann-Whitney test, Kruskal-Wallis test, and chi-square test for trend were applied for statistical analysis.

RESULTS

A total of 836 donors were recruited, of which 35 were excluded because of hemoglobinopathy. An inverse relationship between serum ferritin level and number of donations in the preceding 12 months was observed in both sexes. Iron deficiency was significantly seen in 35.1% of male and 65.3% of female deferred donors. More importantly, up to 7.2, 5.8, and 29.5% of the female donors in groups 1, 2, and 3 were found to be iron deficient despite having a high enough PDH.

CONCLUSION

This is the first study to assess PDH and iron status in Chinese blood donors. Iron depletion is noted with increasing number of blood donations in the preceding 12 months. Advice on iron repletion is a necessary step for donor welfare and strategies should be developed to ensure that donors have adequate PDH.

Clinically significant red blood cell antibodies in chronically transfused patients: a survey of Chinese thalassemia major patients and literature review

BACKGROUND

Red blood cell (RBC) alloimmunization is reported to occur at an incidence of 5.2% to 23.5% among patients with thalassemia requiring chronic transfusion. With very limited data on alloimmunization among the Chinese population, a territory-wide study has been performed to look at its prevalence among Chinese thalassemia major patients.

STUDY DESIGN AND METHODS

A retrospective study was conducted by reviewing RBC request records for patients with thalassemia major in Hong Kong from 2006 to 2009. Demographic information and serologic data were retrieved for analysis.

RESULTS

A total of 382 patients were identified and consisted of 190 males and 192 females with a median age of 23 ± 10.4 (range, 0.25 to 52) years. Eighty-eight patients (23.0%) were reported to have RBC antibodies. Of them, 114 alloantibodies, 18 autoantibodies, and 19 unidentified antibodies were identified. Anti-E (42, 39.3%), anti-Mi(a)/Mur (33, 30.85%), anti-c (14, 13.1%), and anti-Jk(a) (seven, 6.55%) were the commonest antibodies reported. However, one case of anti-K (0.9%) and two cases of anti-Fy(b) (1.9%) were reported. Seven of the 18 patients with autoantibodies contained a total of 13 alloantibodies. They were anti-E (five, 38.4%), anti-Mi(a)/Mur (four, 30.8%), anti-Jk(a) (two, 15.4%), anti-c (one, 7.7%), and anti-Fy(b) (one, 7.7%).

CONCLUSION

It is the first comprehensive study on Chinese thalassemia major patients. Clinically significant alloantibodies are different from those observed in the Western population, although antibodies developed against Rh antigens are still common. Chinese patients are less likely to have antibodies against Kell and Duffy blood group antigens, but are more prone to develop antibodies against the Miltenberger antigens.

Risk factor analysis of hepatitis C virus infection among Chinese blood donors in Hong Kong

BACKGROUND

Hepatitis C virus (HCV) infection can result in serious hepatic complications and hence potentially significant burden to the society. Despite advances in technology, transfusion-transmitted HCV infection still exists. To further minimise the risk, a review on the epidemiology of HCV infection among Chinese blood donors in Hong Kong was conducted.

METHODS

All donations associated with HCV infection confirmed by positive serologic diagnosis with or without molecular confirmation during the period from 2003 to 2010 were studied. Demographic data were retrieved and risk factors were identified.

RESULTS

HCV infection was more commonly seen in first time donors and donors with blood transfusion history before the availability of HCV testing, whereas its association with intravenous drug use was noted to be decreasing. Interestingly, half of the HCV positive donors in 2008-2010 were young donors aged below 21, which was also the group with the highest rate of no known source of infection.

CONCLUSION

A subgroup of younger age donors was found to have no known risk factor. To develop better screening strategy, it is recommended that a more detailed analysis of this group of donors is required.

Halogenated POPs and PAHs in blood plasma of Hong Kong residents

The objective of this study was to quantify organic chlorinated pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs) in blood plasma collected from 111 healthy residents in Hong Kong to assess the levels of these pollutants in the general population during the period of March to April, 2008. Concentrations of these residues in blood plasma obtained from the Hong Kong Red Cross Blood Transfusion Service were determined by gas chromatography-mass spectrometry. Naphthalene, phenanthrene, p,p'-DDE, PCB-180, and PBDE-47 were detected in 100% of the participants. Females had significantly greater concentrations of acenaphthylene (female: 93.3 ng/g lipid; male: 39.8, p < 0.05), anthracene (22.3; 15.3, p < 0.05), fluoranthene (138; 125, p < 0.05), p,p'-DDE, p,p'-DDT, PCB-183, BDE-99 than males. Blood of smokers contained significantly greater (p < 0.05) concentrations of acenaphthene, benzo(a)pyrene, p,p'-DDE, p,p'-DDT, PCB-138, BDE-47, and BDE-99 than did blood of nonsmokers. Positive correlations were found between concentrations of each class of pollutant, with respect to seafood diet habit, Body Mass Index (BMI), and age. Concentrations of HCHs and DDTs in blood plasma of healthy Hong Kong residents were greater than those of other countries, and it was found that smoking, consumption of a seafood diet, BMI, and age could influence concentrations in human blood.

Inventory management

A critical aspect of blood transfusion is the timely provision of high quality blood products. This task remains a significant challenge for many blood services and blood systems reflecting the difficulty of balancing the recruitment of sufficient donors, the optimal utilization of the donor's gift, the increasing safety related restrictions on blood donation, a growing menu of specialized blood products and an ever-growing imperative to increase the efficiency of blood product provision from a cost perspective. As our industry now faces questions about our standard practices including whether or not the age of blood has a negative impact on recipients, it is timely to take a look at our collective inventory management practices. This International Forum represents an effort to get a snap shot of inventory management practices around the world, and to understand the range of different products provided for patients. In addition to sharing current inventory management practices, this Forum is intended to foster an exchange of ideas around where we see our field moving with respect to various issues including specialty products, new technologies, and reducing recipient risk from blood transfusion products.

Development of a fully implantable wireless pressure monitoring system

A fully implantable wireless pressure sensor system was developed to monitor bladder pressures in vivo. The system comprises a small commercial pressure die connected via catheter to amplifying electronics, a microcontroller, wireless transmitter, battery, and a personal digital assistant (PDA) or computer to receive the wireless data. The sensor is fully implantable and transmits pressure data once every second with a pressure detection range of 1.5 psi gauge and a resolution of 0.02 psi. In vitro calibration measurements of the device showed a high degree of linearity and excellent temporal response. The implanted device performed continuously in vivo in several porcine studies lasting over 3 days. This system can be adapted for other pressure readings, as well as other vital sign measurements; it represents the first step in developing a ubiquitous sensing platform for telemedicine and remote patient monitoring.

A telehealth architecture for networked embedded systems: a case study in in vivo health monitoring

The improvement in processor performance through continuous breakthroughs in transistor technology has resulted in the proliferation of lightweight embedded systems. Advances in wireless technology and embedded systems have enabled remote healthcare and telemedicine. While medical examinations could previously extract only localized symptoms through snapshots, now continuous monitoring can discretely analyze how a patient's lifestyle affects his/her physiological conditions and if additional symptoms occur under various stimuli. We demonstrate how medical applications in particular benefit from a hierarchical networking scheme that will improve the quantity and quality of ubiquitous data collection. Our Telehealth networking infrastructure provides flexibility in terms of functionality and the type of applications that it supports. We specifically present a case study that demonstrates the effectiveness of our networked embedded infrastructure in an in vivo pressure application. Experimental results of the in vivo system demonstrate how it can wirelessly transmit pressure readings measuring from 0 to 1.5 lbf/in (2) with an accuracy of 0.02 lbf/in (2). The challenges in biocompatible packaging, transducer drift, power management, and in vivo signal transmission are also discussed. This research brings researchers a step closer to continuous, real-time systemic monitoring that will allow one to analyze the dynamic human physiology.

Clinical trial: percutaneous acetic acid injection vs. percutaneous ethanol injection for small hepatocellular carcinoma--a long-term follow-up study

BACKGROUND

The long-term outcome of percutaneous acetic acid injection (PAI) and percutaneous ethanol injection (PEI) for treating small hepatocellular carcinoma (HCC) remains unclear.

AIM

To compare the long-term outcome of PAI vs. PEI for treating small HCC.

METHODS

From July 1998 to July 2004, 125 patients with small HCC were enrolled. Seventy patients receiving PAI and 55 patients receiving PEI were enrolled. There were no significant differences in the clinical characteristics between the two groups. Tumour recurrence and survival rates were assessed.

RESULTS

Mean follow-up time was 43 months. The local recurrence rate and new tumour recurrence rate were similar between the PAI and PEI groups. The PAI group had significantly better survival than the PEI group (P = 0.027). Multivariate analysis revealed that PAI was the significant factor associated with overall survival [PAI vs. PEI, RR: 0.639, 95% CI: (0.419-1.975), P = 0.038]. The treatment sessions required to achieve complete tumour necrosis were significantly fewer in the PAI group than in the PEI group (2.4 +/- 1.0 vs. 2.9 +/- 1.3, P = 0.018).

CONCLUSION

Percutaneous acetic acid injection required fewer treatment sessions than PEI and provided better survival after long-term follow-up.

Efficacy of a modified improved technique for detecting red cell haemoglobin H inclusions

Alpha-thalassaemia is a common disease in Taiwan. A feature useful in diagnosis is the excess of of beta-chains that result from impaired alpha-chain production. These excess chains assemble into beta 4 tetramers (i.e. Hb H) which can be detected by its rapid anodal migration on alkaline electrophoretic media as seen in Hb H disease. However, this technique cannot, and conventional Hb H inclusion staining rarely can visualize alpha-thalassaemic traits due to small quantities of Hb H formed in these patients. The staining for Hb H inclusion bodies uses brilliant cresyl blue (BCB) or methylene blue (MB) as an oxidant to denature Hb H as intracellular inclusions. We have improved the technique of Jones (who modified the original method in order to obtain enriched young red cells) by prolonging the incubation time from 30 min to 3 h. The sensitivity of this modified improved method was 91% for detecting obligatory alpha-thalassaemic traits as shown in table. No false positive results were seen in beta-thalassaemia or in others. We believe this can be used as a confirmatory test in heterozygous alpha 1-thalassaemia and homozygous alpha 2-thalassaemia.

HLA-DQB1 polymorphisms and risk for cervical cancer: A case-control study in a southern Chinese population

OBJECTIVES AND METHODS

HLA II DQB1 polymorphisms have been shown to associate with cervical cancer risk, but results varied among different populations. In this study, the HLA DQB1 alleles among 221 southern Chinese women with cervical intraepithelial neoplasia grade III (CIN III)/invasive cervical carcinoma (ICC) were compared to 191 controls.

RESULTS

The frequency of DQB1*03 was significantly lower among ICC overall as compared to controls (65.4% vs. 79.1%, odds ratio [95% confidence interval]: 0.50 [0.28-0.88], corrected p-value: 0.04). The protective association of DQB1*03 remained significant for human papillomavirus (HPV) 16-positive ICC, but not for HPV16-negative cases. This is in contrast to studies on European populations where DQB1*03 was associated with an increased risk for ICC. In the current study, 70.1% of the HPV16 isolates were Asian variants, and 28.0% were European variants. However, no significant association between HPV16 variant and DQB1*03 distribution was observed. HPV52 and HPV58 were found respectively in 16.3% and 10.0% of CIN III/ICC, which were higher compared to that of Europe and North America. Further analyses revealed a positive risk association between DQB1*06 and HPV58-positive CIN III/ICC (3.68 [1.37-9.92], corrected p-value: 0.012).

CONCLUSION

The host genetics and the distribution of HPV types/variants may account for the observed differences among southern Chinese and other populations.

Predicting potential drop-out and future commitment for first-time donors based on first 1·5-year donation patterns: the case in Hong Kong Chinese donors

BACKGROUND AND OBJECTIVES

Adequate blood supply is crucial to the health-care system. To maintain a stable donor pool, donation-promotion strategies should not only be targeted in recruitment but also focus on retaining donors to give blood regularly. A study using statistical modelling is conducted to understand the first 4-year donation patterns for drop-out and committed first-time blood donors and to build model for the donor-type identification based on their first 1.5-year donation patterns.

SUBJECTS AND METHODS

First-time whole blood (n= 20 631) adult donors recruited in year 2000 and 2001 in Hong Kong were observed for more than 4 years. Cluster analysis was first applied to group donor type by their similarities in donation behaviour under the surveillance period. A decision tree model based on a shorter surveillance period (1.5 years) is then built to predict the donor type.

RESULTS

Three donation patterns - one-time, drop-out, and committed donor behaviour - were identified in cluster analysis. Three variables - donation frequencies in the first-year and in the half-year period after first year, and the number of donation centre visits in the following half year after first year, were able to predict drop-out donors with potential to become committed and committed donors with relatively lower donation frequency.

CONCLUSIONS

The present statistical modelling is able to identify those donors with potential to become committed donors and those committed donors who can donate more frequently. This information is useful for development of targeted donor retention strategies.

Patients with malignant or pre-malignant cervical lesion have increased risk of becoming hepatitis B carrier

Human Papillomavirus (HPV) and Hepatitis B virus (HBV) are known aetiology of cervical and hepatocellular carcinoma, respectively. Both diseases share a similar clinical course, that is, the vast majority of those infected by these two viruses can eradicate the viruses spontaneously. A small sub-group who fails to clear the virus becomes chronic carrier and can progress to carcinoma many years later. We postulated that patients with pre-malignant or malignant cervical lesion are at increased risk of becoming chronic HBV carrier if infected, which may be attributed to inherent immunological deficiency against viral infection. We tested HBV carrier status from 288 patients with cervical carcinoma, 242 patients with high grade cervical intra-epithelial neoplasia (CIN) and 311 women with neither of the above conditions as control subjects. The HBV carrier rate in the Cancer Group, CIN Group and Control Group was 21.4%, 24.1% and 10.6%. The carrier rate was significantly higher in both the Cancer Group (p<0.01) and the CIN Group (p<0.01), compared to the Control Group. Our study suggests that a common immunological mechanism is involved in eradication of HBV and HPV infections and inherent immuno-deficiency might lead to an association of HBV carrier status with cervical carcinoma. Further studies are needed to confirm our findings and delineate the mechanism involved.

Biofunctionalization of CeF(3):Tb(3+) nanoparticles

CeF(3):Tb(3+) nanoparticles (short pillar-like morphology with an average length and width of 11 and 5 nm, respectively) were successfully prepared by a polyol process using diethyleneglycol (DEG) as solvent. After being functionalized with a SiO(2)-NH(2) layer, these CeF(3):Tb(3+) nanoparticles can be conjugated with biotin molecules (activated by thionyl chloride) and further with avidin. The as-formed CeF(3):Tb(3+) nanoparticles, CeF(3):Tb(3+) nanoparticles functionalized with amino groups, biotin conjugated amino-functionalized CeF(3):Tb(3+) nanoparticles and biotinylated CeF(3):Tb(3+) nanoparticles bonded with avidin were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), UV/vis absorption spectra and luminescence spectra, respectively. The biofunctionalization of the CeF(3):Tb(3+) nanoparticles has less effect on their luminescence properties, i.e. they still show strong green emission (from Tb(3+), with (5)D(4)-(7)F(5) at 543 nm as the most prominent group), indicative of the great potential for these CeF(3):Tb(3+) nanoparticles to be used as biological fluorescence probes.

Association Between HLA-DRB1 polymorphism, high-risk HPV infection and cervical neoplasia in southern Chinese

Multiple determinants are involved in the progression of human papillomavirus (HPV)-infected cervical lesion to invasive cancer. Human leukocyte antigen (HLA) polymorphism seems to play a role. This study examined the association between HLA-DRB1 polymorphism, high-risk HPV infection, and the development of cervical neoplasia in southern Chinese. Three hundred and seventy women with cervical neoplasia (43 cervical intraepithelial neoplasia grade II, 154 grade III, and 173 invasive cancers) and 323 controls were recruited for HLA-DRB1 typing by a sequence-based approach. Cervical specimens were collected for HPV detection by a consensus primer-based polymerase chain reaction, and with the type of HPV identified by hybridization with type-specific oligonucleotide probes. A protective effect of HLA-DRB1*12 for cervical neoplasia was observed, and with stronger associations when subgroup analyses were carried out for patients infected with HPV16 and HPV58. The protective effect of HLA-DRB1*13 that had been reported from other populations was not observed. The data obtained in this study showed that HLA-DRB1*03 conferred a higher risk for HPV18-infected, but not for HPV16-, HPV52-, or HPV58-infected cervical lesions. Although, HPV52 was reported as uncommon worldwide, it was found to be the second most prevalent type in the southern Chinese population. However, no additional risk association was observed when subgroup analyses were performed for HPV52-infected patients. The current study shows that, among southern Chinese, the outcome of HPV-infected cervical lesions is associated with HLA-DRB1 polymorphism. These associations often vary with the type of HPV infection.

CD4+ T-cell responses to Epstein-Barr virus nuclear antigen EBNA1 in Chinese populations are highly focused on novel C-terminal domain-derived epitopes

Epstein-Barr virus nuclear antigen EBNA1, the one viral protein uniformly expressed in nasopharyngeal carcinoma (NPC), represents a prime target for T-cell-based immunotherapy. However, little is known about the EBNA1 epitopes, particularly CD4 epitopes, presented by HLA alleles in Chinese people, the group at highest risk for NPC. We analyzed the CD4+ T-cell responses to EBNA1 in 78 healthy Chinese donors and found marked focusing on a small number of epitopes in the EBNA1 C-terminal region, including a DP5-restricted epitope that was recognized by almost half of the donors tested and elicited responses able to recognize EBNA1-expressing, DP5-positive target cells.

Core-shell structured SiO2@YVO4:Dy3+/Sm3+ phosphor particles: sol-gel preparation and characterization

Spherical SiO(2) particles have been coated with YVO(4):Dy(3+)/Sm(3+) phosphor layers by a Pechini sol-gel process, leading to the formation of core-shell structured SiO(2)@YVO(4):Dy(3+)/Sm(3+) particles. X-ray diffraction (XRD), Fourier-transform IR spectroscopy, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), photoluminescence (PL) spectra as well as lifetimes were used to characterize the resulting SiO(2)@YVO(4):Dy(3+)/Sm(3+) core-shell phosphors. The obtained core-shell phosphors have perfect spherical shape with narrow size distribution (average size ca. 300 nm), smooth surface and non-agglomeration. The thickness of shells could be easily controlled by changing the number of deposition cycles (20 nm for one deposition cycle). The core-shell particles show strong characteristic emission from Dy(3+) for SiO(2)@YVO(4):Dy(3+) and from Sm(3+) for SiO(2)@YVO(4):Sm(3+) due to an efficient energy transfer from YVO(4) host to them. The PL intensity of Dy(3+) and Sm(3+) increases with raising the annealing temperature and the number of coating cycles.

Prevention of transfusion-transmitted hepatitis E by donor-initiated self exclusion

Safety in blood transfusion has all along been focused on blood borne viruses like HIV, hepatitis B and C. However, infective agents that are not usually transmitted through blood may also pose risk to transfusion if the donor gives blood in the early-viraemic phase. A case report of potential transfusion-transmitted hepatitis E (HEV) is described. It shows the virus can be transmissible via blood because of the presence of HEV RNA in the blood donated. Pre-donation health screening was unable to exclude this asymptomatic donor. But donor-initiated call back system which acts as an additional safety net prevented the release of the potential infective blood products.

Unrelated umbilical cord blood transplantation in children: experience of the Hong Kong Red Cross Blood Transfusion Service

OBJECTIVE

To review the outcome of unrelated umbilical cord blood transplantation in children using cord blood from the Hong Kong Red Cross Blood Transfusion Service.

DESIGN

Retrospective study.

PATIENTS

Records of eight patients who received unrelated umbilical cord blood transplants between 1999 and 2003 were reviewed.

MAIN OUTCOME MEASURES

Engraftment of haematopoietic cells and graft-versus-host disease after transplantation.

RESULTS

The median age of the patients was 4.9 years (range, 1.0-9.4 years). Five patients had acute leukaemia, one had non-Hodgkin's lymphoma, one had X-linked adrenoleukodystrophy, and one had mucolipidosis. The infused umbilical cord blood units contained a median of 6.7 x 10(7) /kg nucleated cells and 4.0 x 10(5) /kg CD34-positive cells. Neutrophil engraftment was achieved at a median of 13 days (range, 11-19 days) and, for seven patients, platelet engraftment was achieved at a median of 39 days (range, 24-98 days). Acute graft-versus-host disease occurred in all patients (grades I to III). One of the patients died because of encephalitis; of the other seven, five developed chronic graft-versus-host disease of the skin. At a median follow-up of 2 years, the four patients with leukaemia and the one with non-Hodgkin's lymphoma remained in continuous complete remission; the patient with adrenoleukodystrophy showed stabilisation of neurological condition.

CONCLUSION

The Hong Kong Red Cross Blood Transfusion Service Cord Blood Bank stored cord blood units of good quality for transplantation, the outcome of which was comparable to that of bone marrow transplantation.

Endoscopic balloon dilatation is a safe method in the management of common bile duct stones

BACKGROUNDS AND AIMS

Endoscopic sphincterotomy is a widely accepted treatment for patients with common bile duct stones. Despite improvement in this technique, endoscopic sphincterotomy is still associated with some biliary complications. Endoscopic balloon dilatation is a less traumatic and sphincter preserving method for removal of common bile duct stones. However, the results of controlled studies in comparison with these two methods are contradictory. The aim of this study is to compare the safety and efficacy of endoscopic balloon dilatation and endoscopic sphincterotomy in Chinese patients.

PATIENTS AND METHODS

A total of 104 patients with common bile duct stones on endoscopic retrograde cholangiopancreatography were enrolled. They were randomly assigned to endoscopic balloon dilatation or endoscopic sphincterotomy. Endoscopic balloon dilatation was performed by using a balloon dilator to dilate the sphincter for 5 min. The common bile duct stones were then removed by a Dormia basket after endoscopic balloon dilatation or endoscopic sphincterotomy. Mechanical lithotripsy was performed if the stones were difficult to remove by Dormia basket. After discharge, patients were regularly followed up for biliary complications.

RESULTS

The successful bile duct stone clearance rate was 94.1% in endoscopic balloon dilatation group and 100% in endoscopic sphincterotomy group. Post-procedural significant haemorrhage was higher in endoscopic sphincterotomy group than in endoscopic balloon dilatation group (14/53 versus 1/48, P < 0.001). The bleeding patient from endoscopic balloon dilatation group was a case of uremia and bleeding occurred 48 h after endoscopic balloon dilatation. All the patients with post-procedural haemorrhage were controlled endoscopically. The post-procedural serum amylase level showed no significant difference in both groups and none of them developed clinical pancreatitis. After a mean 16 months follow-up, three patients (6.3%) in endoscopic balloon dilatation group and four patients (7.5%) in endoscopic sphincterotomy group developed recurrent common bile duct stones. The recurrent common bile duct stones were multiple and muddy in consistency. They were successfully removed endoscopically.

CONCLUSION

Both endoscopic balloon dilatation and endoscopic sphincterotomy are safe and effective techniques for the treatment of common bile duct stones. Endoscopic balloon dilatation can be safely applied in patients with coagulopathy and does not increase the incidence of pancreatitis or bleeding.

Prevalence and specificity of clinically significant red cell alloantibodies in Chinese women during pregnancy--a review of cases from 1997 to 2001

Guidelines for the prevention and management of red cell alloantibodies during pregnancy, related to anti-D in particular, are well established in Caucasian populations. However, because of the racial difference of the blood group distribution, applicability to Chinese is unknown as a result of insufficient data on the prevalence and their outcome. In a retrospective review of 28,303 (21,327 Chinese) antenatal attendances from 1997 to 2001, 213 (0.79%) women were found to have a total of 230 irregular antibodies. About 137 (0.64%) were ethnic Chinese, and a total of 160 irregular antibodies were identified in their blood samples. About 58 of these Chinese women (0.27%) were found to have 66 clinically significant antibodies. There was only one case of anti-D detected in an Rh(D)-negative subject. Our study shows the overall prevalence of clinically significant antibodies in Chinese women, which was not different from that of the Western population. However, the specificities of the antibodies differ with the commonest antibodies encountered; these being anti-Mi (57.6%), anti-E (19.7%), anti-S (10.6%) and anti-c (7.6%). Neonatal jaundice was observed in 37 babies and 10 of them required phototherapy. The findings support the previous recommendation that routine antenatal antibody screening for Chinese women may not be worthwhile except in Rh(D)-negative subjects or those with an antecedent history of haemolytic disease of the newborn (HDN). The relative high incidence of anti-Mi in the present study and the local population, in general, may warrant a large-scale prospective study of pregnancy outcome in these subjects, especially in the light of the previous case reports of HDN because of anti-Mi.

Estimation of bacterial risk in extending the shelf life of PLT concentrates from 5 to 7 days

BACKGROUND

The use of bacterial culture to prevent bacterial contamination of blood components has renewed interest for extending the shelf life of PLT concentrates to 7 days after collection.

STUDY DESIGN AND METHODS

This study was therefore conducted to determine the residual risk of bacterial contamination in PLT concentrates at the end of 5 and 7 days after collection in a center where all PLT concentrates are routinely screened by taking samples on Day 2 for culture. PLT units with no growth after 48 hours were sampled a second time on Day 5 or Day 7 after collection, followed by inoculation into aerobic culture bottles. The inoculated bottles were then monitored for up to 7 days at 35 degrees C in an automatic monitoring and detection system.

RESULTS

During a 16-month study period, a total of 6020 PLT concentrates were tested 5 days (Group A, n=3010) and 7 days (Group B, n=3010) after collection. Four units in each group (0.133%) were found to be contaminated. In 6 units, bacteria were seen on direct Gram stain. In addition, 5 of the associated RBC units grew the same organisms on culture. The organisms include three coagulase-negative staphylococci and five Propionibacterium acnes. The positive rate of routine short-term bacterial culture was 0.035 percent during the same study period.

CONCLUSION

Despite routine short-term bacterial culture, a significant risk of bacterial contamination remains at 5 and 7 days after collection. For now, the shelf life of PLT concentrates should remain 5 days.