Salmonella contamination in non-UK produced shell eggs on retail sale in some regions of England.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
C H Chan
Publications and source records attributed to C H Chan.
Efficient calculation of electron diffraction for the structural determination of nanomaterials.
A critical advance in the technique of low-energy electron diffraction is presented and shown to enable determining detailed structures of nanomaterials, based on experimental methods that already exist or have been proposed. Our new cluster approach speeds up the computation to scale as n logn, rather than the current n3 or n2, with n the number of atoms, for example. Applications are illustrated for C60 molecules adsorbed on a Cu(111) surface, with and without coadsorbed metal atoms, exhibiting sensitivity to important structural features such as buckyball size and deformation.
Journal Article↗
A comparison of European and North American atmospheric deposition networks: polycyclic aromatic hydrocarbons and lindane.
A comparison between the sampling and analytical methods used by Canadian (IADN) and German (OSPAR) regional monitoring networks for persistent organic pollutants was conducted from September 2002 to October 2003 at a rural site in Ontario, Canada. Polycyclic aromatic hydrocarbons (PAHs) and the currently-used pesticide lindane were measured in precipitation and ambient air samples. Overall the two networks sampling and analytical methods agreed well in their results of deposition (wet and dry particulate). Lindane concentrations between the two networks agreed well in the air samples while too few precipitation samples could be compared to conclude on agreement. The lindane seasonal profile with a peak in spring-early summer was consistent with previous results pointing to the continued use of this pesticide in 2002-2003 in Canada. Annual lindane wet depositions were comparable between the two network methodologies. PAHs concentrations in precipitation and in gas phase agreed well while there was a discrepancy for particulate PAHs in air. This study confirmed that the use of data from the two regional POPs monitoring networks for hemispherical modelling studies is warranted.
Air Pollutants↗
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.
Adult↗
Non-contact infrared thermal imagers may still be useful for mass fever screening.
Explore the source record for details and available documents.
Fever↗
Obstructive sleep apnoea in children with Down syndrome.
INTRODUCTION: Children with Down syndrome (DS) are prone to develop obstructive sleep apnoea (OSA) for a combination of reasons, including small upper airway, midfacial hypoplasia, micrognathia and muscular hypotonia. The objective of this study was to compare the prevalence of OSA in DS children, with or without snoring, with snoring children matched for gender, age and weight for height. METHODS: DS children were prospectively recruited from the Hong Kong Down Syndrome Association. All recruited DS children underwent a sleep polysomnography (PSG) in our sleep laboratory. The same number of patients without DS who underwent sleep PSG in the same period were enrolled as controls after they were matched for gender, age and weight for height. OSA was defined as apnoea-hypopnoea index (AHI) greater than 1.5. RESULTS: 22 DS patients and 22 snoring controls completed the overnight PSG. The mean age of DS children and snoring controls was 10.82 +/- 5.93 and 10.27 +/- 5.68 years, respectively. The prevalence of OSA was 59 percent in DS children and 32 percent in snoring controls. Median and interquartile range (IQR) of AHI of DS children (median 1.80, IQR is 0.40 to 7.10) were significantly higher than those of controls (median 0.50, IQR is 0.00 to 2.03, p-value equals 0.041). Out of 13 DS children with OSA, eight of them (61.5 percent) had no habitual snoring. CONCLUSION: 59 percent of DS children in the current series were found to have OSA and they were more likely to develop OSA than controls. Nearly 40 percent of DS children with OSA did not have habitual snoring.
Adolescent↗
Application of artificial neural networks to establish a predictive mortality risk model in children admitted to a paediatric intensive care unit.
INTRODUCTION: Paediatric risk of mortality and paediatric index of mortality (PIM) are the commonly-used mortality prediction models (MPM) in children admitted to paediatric intensive care unit (PICU). The current study was undertaken to develop a better MPM using artificial neural network, a domain of artificial intelligence. METHODS: The purpose of this retrospective case series was to compare an artificial neural network (ANN) model and PIM with the observed mortality in a cohort of patients admitted to a five-bed PICU in a Hong Kong non-teaching general hospital. The patients were under the age of 17 years and admitted to our PICU from April 2001 to December 2004. Data were collected from each patient admitted to our PICU. All data were randomly allocated to either the training or validation set. The data from the training set were used to construct a series of ANN models. The data from the validation set were used to validate the ANN and PIM models. The accuracy of ANN models and PIM was assessed by area under the receiver operator characteristics (ROC) curve and calibration. RESULTS: All data were randomly allocated to either the training (n=274) or validation set (n=273). Three ANN models were developed using the data from the training set, namely ANN8 (trained with variables required for PIM), ANN9 (trained with variables required for PIM and pre-ICU intubation) and ANN23 (trained with variables required for ANN9 and 14 principal ICU diagnoses). Three ANN models and PIM were used to predict mortality in the validation set. We found that PIM and ANN9 had a high ROC curve (PIM: 0.808, 95 percent confidence interval 0.552 to 1.000, ANN9: 0.957, 95 percent confidence interval 0.915 to 1.000), whereas ANN8 and ANN23 gave a suboptimal area under the ROC curve. ANN8 required only five variables for the calculation of risk, compared with eight for PIM. CONCLUSION: The current study demonstrated the process of predictive mortality risk model development using ANN. Further multicentre studies are required to produce a representative ANN-based mortality prediction model for use in different PICUs.
Adolescent↗
Assessment of the Pediatric Index of Mortality (PIM) and the Pediatric Risk of Mortality (PRISM) III score for prediction of mortality in a paediatric intensive care unit in Hong Kong.
OBJECTIVE: To compare two models (The Pediatric Risk of Mortality III score and Pediatric Index of Mortality) for prediction of mortality in a paediatric intensive care unit in Hong Kong. DESIGN: Prospective case series. SETTING: A five-bed paediatric intensive care unit in a general hospital in Hong Kong. PATIENTS: All patients consecutively admitted to the unit between April 2001 and March 2003. MAIN OUTCOME MEASURES: Scores for both models compared with observed mortality. RESULTS: A total of 303 patients were admitted to the paediatric intensive care unit during the study period. The median age was 2 years, with an interquartile range of 7 months to 7 years. The male to female ratio was 169:134 (55.8%:44.2%). The median length of hospital stay was 3 days. The overall predicted number of deaths using The Pediatric Risk of Mortality III score was 10.2 patients whereas that by Pediatric Index of Mortality was 13.2 patients. The observed mortality was eight patients. The area under the receiver operating characteristics curve for the two models was 0.910 and 0.912, respectively. CONCLUSION: The predicted mortality using both prediction models correlated well with the observed mortality.
Child↗
Improvement of adenoidectomy for childhood snoring.
Explore the source record for details and available documents.
Adenoidectomy↗
Prescription of codeine in young infants.
Explore the source record for details and available documents.
Antitussive Agents↗
Consolidation therapy with autologous blood stem cell transplantation in a patient with primary plasma cell leukaemia.
Primary plasma cell leukaemia (PPCL) is a rare form of plasma cell dyscrasia. Conventional melphalan-based treatment is often ineffective, with a reported median survival of 2-7 months only. We report a 53-year-old man with PPCL who was treated with four cycles of combination chemotherapy including vincristine, adriamycin and dexamethasone that resulted in a good partial remission. High-dose melphalan 200 mg/m2 and autologous peripheral blood stem cell (PBSC) rescue was then given 6 months after diagnosis. Maintenance interferon-alpha was started 8 weeks after transplantation with good drug compliance. Complete remission was achieved and molecular remission was documented 11 months after autologous PBSC transplantation. In conclusion, high-dose therapy followed by autologous stem cell rescue is a feasible option for PPCL that can result in a reasonably sustained remission.
Antineoplastic Combined Chemotherapy Protocols↗
[Severe acute respiratory syndrome (SARS)].
The severe acute respiratory syndrome (SARS) is a highly infectious respiratory disease, to the best of our knowledge caused by a hitherto unknown corona virus. The virus has spread from South East Asia to many countries of the world. Three case reports of patients from the Prince of Wales Hospital of The Chinese University of Hong Kong demonstrate typical clinical courses. Fever, cough, in most cases non-productive, myalgia, chills, and rigor are the leading symptoms. Leucopenia and thrombocytopenia are the most prominent laboratory parameters, increased values for lactatedehydrogenase (LDH) reflect a more severe clinical course. Advanced age and coexisting conditions seem to influence the prognosis unfavourably. The chest roentgenogram may be normal initially but at a later stage progressive consolidations in the majority of peripheral parts of the lung are observed, which cannot be differentiated from pneumonias of other origin. Even young patients can enter a stage of respiratory compromise rather fast. A therapy against the cause of the disease is not known. Empirical therapy with ribavirin in combination with high dose corticosteroids have proved successful. The disease may progress into respiratory failure comparable with an acute respiratory distress syndrome (ARDS). Mortality is around five to ten per cent. Stringent hygiene and quarantine measures are mandatory to prevent the further spread of this threatening disease.
Adult↗
Arsenic trioxide in comparison with chemotherapy and bone marrow transplantation for the treatment of relapsed acute promyelocytic leukaemia.
BACKGROUND: The best overall treatment strategy for patients with acute promyelocytic leukaemia (APL) in relapse with chemotherapy, bone marrow transplantation (BMT) or arsenic trioxide (As(2)O(3)) based therapy remains undefined. PATIENTS AND METHODS: We reviewed the clinical course and treatment outcome of 143 APL cases seen in four major hospitals in Hong Kong over a 10-year period. RESULTS: Complete remission (CR) was attained in 113 cases (79%) with all-trans retinoic acid (ATRA) and chemotherapy. Relapse occurred at a median of 16 months in 54 cases, with a 3-year disease free survival of 56%. Post-relapse treatment was successful in 41 cases (76%), giving an actuarial 3-year overall survival (OS) of 81% from CR1. Three different protocols were used: chemotherapy alone (n = 19), allogeneic BMT (n = 14) and an As(2)O(3)-based regimen (n = 21). Chemotherapy was associated with the highest treatment-related mortality (TRM) at 53%, giving a CR2 rate of 47%. TRM was 36% for BMT. The CR2 rate for the As(2)O(3)-based regimen was 100%, with no TRM. However, 38% of As(2)O(3) treated patients had subsequent relapses, which were further salvaged in 75% by combined As(2)O(3) plus ATRA. The actuarial OS for the three protocols leveled off by 2 years at 82% for As(2)O(3), 43% for BMT and 23% for chemotherapy (P = 0.0004). CONCLUSIONS: Our results suggest that As(2)O(3) may be superior to chemotherapy and BMT for the treatment of APL in relapse.
Adolescent↗
Clinical profiles of human immunodeficiency virus-associated lymphoma in Hong Kong.
OBJECTIVE: To identify the clinical and prognostic features of human immunodeficiency virus-associated lymphoma in the local population with a view to designing more effective treatment strategies. DESIGN: Retrospective review. SETTING: Referral hospital, Hong Kong. SUBJECTS AND METHODS: All patients (n=10) with human immunodeficiency virus-associated lymphoma managed at Queen Elizabeth Hospital from January 1995 to December 2001. RESULTS: All patients were men with a median age of 39 years. The median CD4 cell count at the time of diagnosis of lymphoma was 0.056 x 10(9)/L. All tumours were diffuse large B-cell lymphomas, with the exception of one systemic Burkittlike lymphoma. Systemic lymphoma was diagnosed in seven patients and three had primary central nervous system lymphoma. Combined antiretroviral therapy was continued or given to five of the six patients who received some form of chemotherapy or radiotherapy treatment. Of the two patients with primary central nervous system lymphoma who received whole brain irradiation therapy, one patient survived 41 months in clinical remission after diagnosis and the other patient died of sepsis while in partial remission 19 months after diagnosis. The four patients with systemic lymphoma who received standard- or reduced-dose chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone had a median survival of 3 months. CONCLUSION: The clinical profiles of these patients were similar to those of patients with human immunodeficiency virus-associated lymphoma in western countries. The overall survival of patients was poor with conventional chemoradiotherapy. Other innovative treatment approaches should be investigated to prolong the survival of this patient group.
Adolescent↗
Idiopathic myelofibrosis with extramedullary haemopoiesis involving the urinary bladder in a Chinese lady.
Extramedullary haemopoiesis (EMH) associated with idiopathic myelofibrosis most commonly involves the reticuloendothelial organs, such as the spleen and liver, although ectopic haemopoietic tissue has also been described rarely in the lymph nodes, skin, gastrointestinal tract, pleura, peritoneum, central nervous system, and genital and urinary tracts. We report on a 54-year-old Chinese lady with a long history of idiopathic myelofibrosis who presented with gross haematuria and left hydronephrosis due to EMH in the bladder trigone. Cystoscopic examination revealed a sessile necrotic papillary growth at the trigone, obstructing the left ureteric orifice. Transurethral resection of the bladder tumour was performed, and microscopic examination of the tumour chips demonstrated atypical megakaryocytes, immature granulocytes and normoblasts, confirming the presence of EMH. The residual bladder tumour responded well to low dose radiotherapy, with subsequent disappearance of haematuria and normalization of ultrasonogram findings.
Cell Lineage↗
The B-cell receptor of a hepatitis C virus (HCV)-associated non-Hodgkin lymphoma binds the viral E2 envelope protein, implicating HCV in lymphomagenesis.
Hepatitis C virus (HCV) infection is associated with extrahepatic B-cell lymphoproliferative disorders. To determine whether a viral antigen drives this B-cell expansion, the B-cell receptors were cloned from HCV-associated lymphomas and were expressed as soluble immunoglobulins. The rescued immunoglobulins were then tested for their ability to bind the HCV-E2 envelope glycoprotein, an antigen that was previously implicated in the pathogenesis of HCV-associated B-cell diseases. One of 2 lymphoma immunoglobulin test cases bound the E2 protein in a manner identical to a bona fide human anti-E2 antibody. Moreover, it bound E2 from multiple viral genotypes, suggesting reactivity with a conserved E2 epitope. These findings support the hypothesis that some HCV-associated lymphomas originate from B cells that were initially activated by the HCV-E2 protein and might explain the association between HCV infection and some B-cell lymphoproliferative disorders.
Amino Acid Sequence↗
Chondroblastoma of the lumbar vertebra.
Chondroblastoma of the vertebra is a very rare condition. To our knowledge fewer than 20 cases have been reported in the world literature. We report a 54-year-old man with chondroblastoma of the fifth lumbar vertebra. The clinical and radiological aspects of the tumor are discussed, emphasizing the presence of an extraosseous mass suggestive of locally aggressive behavior.
Chondroblastoma↗
V(H)1-69 gene is preferentially used by hepatitis C virus-associated B cell lymphomas and by normal B cells responding to the E2 viral antigen.
Hepatitis C virus (HCV)-associated B cell lymphomas were previously shown to express a restricted repertoire of immunoglobulin V(H) and V(L) genes, V(H)1-69 and VkappaA27, respectively. Although this suggests a role for antigen selection in the pathogenesis of these lymphomas, the driving antigen involved in the clonal expansion has not been identified. B cell response to a viral antigen, the HCV envelope glycoprotein 2 (E2), was analyzed in an asymptomatic HCV-infected patient. Single B cells, immortalized as hybridomas and selected for binding E2, were analyzed for their V gene usage. Sequences of these V region genes demonstrated that each hybridoma expressed unique V(H) and V(L) genes. Remarkably, these anti-E2 hybridomas preferentially used the V(H)1-69 gene. Analysis of replacement to silent mutation ratios indicated that the genes underwent somatic mutation and antigenic selection. In a separate report, human anti-E2 antibodies were also shown to express the same V(H) gene. These data strengthen the hypothesis that the HCV-associated lymphomas are derived from clonally expanded B cells stimulated by HCV.
Amino Acid Sequence↗