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1.
BMC Ophthalmol ; 23(1): 392, 2023 Sep 26.
Article in English | MEDLINE | ID: mdl-37752479

ABSTRACT

BACKGROUND: To evaluate the feasibility of creating flanges using an optic piercing technique with a 6 - 0 polypropylene monofilament for scleral fixation of dislocated one-piece diffractive multifocal intraocular lenses (IOLs). STUDY DESIGN: Experimental study and case series. SUBJECTS: Optical bench test and eyes with IOL dislocation. METHODS: Two separate 6 - 0 polypropylenes were penetrated twice at the opposite peripheral optic of the TECNIS Synergy IOL (Johnson & Johnson Vision). The root mean square of the modulation transfer function (MTFRMS), at between + 1.00 and - 4.00 D of defocus, was measured in the TECNIS Synergy IOL both with and without optic piercing in the optical bench study. This case series included three eyes from two patients who underwent scleral-fixation of multifocal IOLs using the four-flanged polypropylene optic piercing technique. The postoperative corrected distance visual acuity (CDVA) at 4 m, the uncorrected near visual acuity (UNVA) at 40 cm, and IOL centration were evaluated. RESULTS: The optical bench test showed no differences in MTFRMS values measured in the TECNIS Synergy IOL, either with or without optic piercing at all defocuses. In all three case series, the postoperative CDVA at 4 m was 20/20 and UNVA at 40 cm was J1. Postoperative anterior segment photographs showed good centration of IOLs in all cases. CONCLUSION: The four-flanged polypropylene optic piercing technique for multifocal IOL scleral fixation can provide excellent clinical outcomes and IOL stability after surgery without diminishing the performance of the multifocal IOLs.


Subject(s)
Lenses, Intraocular , Multifocal Intraocular Lenses , Humans , Polypropylenes , Lens Implantation, Intraocular/methods , Visual Acuity
2.
Pediatr Transplant ; 26(5): e14278, 2022 08.
Article in English | MEDLINE | ID: mdl-35396908

ABSTRACT

BACKGROUND: Hemoglobin (Hb) Hammersmith is a rare form of unstable ß-chain hemoglobinopathy causing hemolytic anemia. This rare event led to a more serious transfusion-dependent phenotype in a patient. It was successfully cured by haploidentical hematopoietic stem cell transplantation (HSCT). METHODS AND RESULTS: A 9-year-old mainland Chinese male with a history of neonatal unconjugated hyperbilirubinemia was diagnosed to have hemoglobin (Hb) Hammersmith. He required regular blood transfusion but was unable to be transfused to desired parameters for 8 years prior to transplant due to social and geographical reasons. He subsequently developed marrow hyperplasia and progressive splenomegaly (down to umbilicus level), suggestive of extramedullary hematopoiesis. Eventually, the family came to Hong Kong and complied to a more intensive transfusion regimen and preconditioning chemotherapy 3 months prior to transplant. He underwent haploidentical HSCT using paternal TCRαß/CD45RA-depleted graft but suffered from graft rejection, despite splenic irradiation for massive splenomegaly. It was successfully salvaged with second HSCT with unmanipulated graft from the same donor with additional serotherapy and donor lymphocyte infusions. CONCLUSION: Allogenic haploidentical HSCT for hemoglobin Hammersmith is feasible but adequate immunosuppression during conditioning is crucial. Precise adoptive cell therapy can promote durable engraftment.


Subject(s)
Hematopoietic Stem Cell Transplantation , Splenomegaly , Transfusion Reaction , Asian People , Child , Haploidy , Hemoglobins, Abnormal , Humans , Living Donors , Lymphocyte Transfusion , Lymphocytes , Male , Splenomegaly/etiology , Splenomegaly/therapy
3.
Ann Hematol ; 98(4): 869-879, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30515541

ABSTRACT

Current prognostication in myelofibrosis (MF) is based on clinicopathological features and mutations in a limited number of driver genes. The impact of other genetic mutations remains unclear. We evaluated for mutations in a myeloid panel of 54 genes using next-generation sequencing. Multivariate Cox regression analysis was used to determine prognostic factors for overall survival (OS) and leukaemia-free survival (LFS), based on mutations of these genes and relevant clinical and haematological features. One hundred and one patients (primary MF, N = 70; secondary MF, N = 31) with a median follow-up of 49 (1-256) months were studied. For the entire cohort, inferior OS was associated with male gender (P = 0.04), age > 65 years (P = 0.04), haemoglobin < 10 g/dL (P = 0.001), CUX1 mutation (P = 0.003) and TP53 mutation (P = 0.049); and inferior LFS was associated with male gender (P = 0.03), haemoglobin < 10 g/dL (P = 0.04) and SRSF2 mutations (P = 0.008). In primary MF, inferior OS was associated with male gender (P = 0.03), haemoglobin < 10 g/dL (P = 0.002), platelet count < 100 × 109/L (P = 0.02), TET2 mutation (P = 0.01) and CUX1 mutation (P = 0.01); and inferior LFS was associated with haemoglobin < 10 g/dL (P = 0.02), platelet count < 100 × 109/L (P = 0.02), TET2 mutations (P = 0.01) and CUX1 mutations (P = 0.04). These results showed that clinical and haematological features and genetic mutations should be considered in MF prognostication.


Subject(s)
High-Throughput Nucleotide Sequencing , Mutation , Primary Myelofibrosis , Adult , Aged , Aged, 80 and over , Asian People , China/epidemiology , DNA Mutational Analysis , Disease-Free Survival , Female , Follow-Up Studies , Humans , Male , Middle Aged , Platelet Count , Primary Myelofibrosis/blood , Primary Myelofibrosis/genetics , Primary Myelofibrosis/mortality , Sex Factors , Survival Rate
4.
Am J Hematol ; 94(6): 650-657, 2019 06.
Article in English | MEDLINE | ID: mdl-30900772

ABSTRACT

The present study aimed to define a subtype of complex/monosomal karyotype (CK/MK) acute myeloid leukemia (AML) by its distinct clinical features, p53 signaling and responses to p53 targeting agents. Ninety-eight young adults (range: 21-60 years; median: 49 years) with CK/MK AML were studied. They received standard induction, consolidation and allogeneic hematopoietic stem cell transplantation from siblings or matched unrelated donors if available. Chromosomal abnormalities most commonly affected chromosome 5 (30%), 7 (22%) and 17 (21%). Next generation sequencing of a 54-myeloid gene panel were available in 76 patients. Tumor protein 53 (TP53) mutations were most common (49%) and associated with the presence of -5/5q- (P < .001) and -17/17p- (P < .001), but not -7/7q- (P = .370). This "typical" CK/MK AML subtype was associated with significantly lower presenting white cell counts, higher number of karyotypic abnormalities, and inferior leukemia-free and overall survivals, compared with CK/MK AML without the typical features. Blood or bone marrow samples from typical CK/MK AML patients showed defective p53 signaling upon induction by etoposide. In vitro drug sensitivity analysis showed that they were sensitive to APR-246 that targeted mutant p53, but resistant to MDM2 antagonist MI-77301. Novel therapeutic strategies targeting TP53 mutations in CK/MK AML should be developed and tested in clinical trials.


Subject(s)
Abnormal Karyotype , Antineoplastic Agents/administration & dosage , Chromosomes, Human , Drug Resistance, Neoplasm , Leukemia, Myeloid, Acute , Monosomy , Tumor Suppressor Protein p53 , Adolescent , Adult , Chromosomes, Human/genetics , Chromosomes, Human/metabolism , Drug Resistance, Neoplasm/drug effects , Drug Resistance, Neoplasm/genetics , Female , Humans , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/metabolism , Leukemia, Myeloid, Acute/pathology , Male , Middle Aged , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
6.
Tob Control ; 25(6): 685-691, 2016 11.
Article in English | MEDLINE | ID: mdl-26585706

ABSTRACT

OBJECTIVES: To examine trends in deaths for conditions associated with secondhand smoke exposure over the years prior to and following the implementation of a smoke-free policy in Hong Kong. DESIGN: Time-series study. SETTING: Death registration data from Hong Kong Special Administrative Region (SAR) Government Census and Statistics Department. PARTICIPANTS: All deaths registered from 1 January 2001 to 31 December 2011. MAIN OUTCOME MEASURES: Deaths for conditions associated with passive smoking include cardiovascular disease (CVD), respiratory disease and other causes. RESULTS: There was a decline in the annual proportional change for ischaemic heart disease (IHD), acute myocardial infarction (AMI) and CVD mortality in the year after the intervention for all ages and those aged 65 years or older. There were also clear declines in the cool season peaks for these three conditions in the first postintervention year. There was a further drop in the cool season peak for AMI among all ages in the year after the exemptions ceased. No declines in annual proportional change or changes in seasonal peaks of mortality were found for any of the control conditions. CONCLUSIONS: The findings in this study add to the evidence base, as summarised in the Surgeon General's report, extending the impact of effective smoke-free legislation to those aged 65 years or older and to cerebrovascular events in younger age groups. They also reinforced the need for comprehensive, enforced and effective smoke-free laws if the full extent of the health gains are to be achieved.


Subject(s)
Cardiovascular Diseases/epidemiology , Smoke-Free Policy , Smoking Prevention/legislation & jurisprudence , Tobacco Smoke Pollution/prevention & control , Adult , Age Factors , Aged , Cardiovascular Diseases/mortality , Female , Hong Kong/epidemiology , Humans , Male , Middle Aged , Myocardial Infarction/epidemiology , Myocardial Infarction/mortality , Myocardial Ischemia/epidemiology , Myocardial Ischemia/mortality , Respiratory Tract Diseases/epidemiology , Respiratory Tract Diseases/mortality , Seasons , Time Factors , Tobacco Smoke Pollution/adverse effects
7.
Hemoglobin ; 40(4): 260-3, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27240426

ABSTRACT

Hb Tarrant [α126(H9)Asp→Asn; HBA2: c.379G > A (or HBA1)], is a rare high oxygen affinity hemoglobin (Hb) variant that causes erythrocytosis, previously described in a few Mexican-American families. Here we report the first Chinese family with this Hb variant presenting with unexplained familial erythrocytosis. No evidence of hemolysis was seen. A locally adapted approach to the diagnostic process in clinical laboratories is discussed. Molecular analysis has an important role in confirmation of the diagnosis. Proper identification of this rare but clinically significant Hb variant is helpful for family counseling and will help to guide appropriate management of absolute erythrocytosis.


Subject(s)
Hemoglobins, Abnormal , Polycythemia/congenital , Polycythemia/genetics , Asian People , Clinical Laboratory Techniques/methods , Humans , Molecular Diagnostic Techniques , Pedigree , Polycythemia/etiology
9.
Front Oncol ; 14: 1364199, 2024.
Article in English | MEDLINE | ID: mdl-38595820

ABSTRACT

Introduction: Medulloblastoma is the most common malignant brain tumor in children, often requiring intensive multimodal therapy, including chemotherapy with alkylating agents. However, therapy-related complications, such as therapy-related myeloid neoplasms (t-MNs), can arise, particularly in patients with genetic predisposition syndromes. This case report presents three pediatric cases of medulloblastoma with subsequent development of t-MNs, highlighting the potential role of genetic predisposition and the importance of surveillance for hematological abnormalities in long-term survivors. Case presentation: We describe three cases of pediatric medulloblastoma who developed t-MNs after receiving chemotherapy, including alkylating agents. Two of the patients had underlying genetic predisposition syndromes (TP53 pathologic variants). The latency period between initial diagnosis of medulloblastoma and the development of secondary cancer varied among the cases, ranging from 17 to 65 months. The three cases eventually succumbed from secondary malignancy, therapy-related complications and progression of primary disease, respectively. Conclusions: This report highlights the potential association between genetic predisposition syndromes and the development of therapy-related myeloid neoplasms in pediatric medulloblastoma survivors. It underscores the importance of surveillance for hematological abnormalities among such patients.

10.
Blood ; 117(18): 4935-45, 2011 May 05.
Article in English | MEDLINE | ID: mdl-21385855

ABSTRACT

Fetal hemoglobin (HbF) is regulated as a multigenic trait. By genome-wide association study, we confirmed that HBS1L-MYB intergenic polymorphisms (HMIP) and BCL11A polymorphisms are highly associated with HbF in Chinese ß-thalassemia heterozygotes. In this population, the variance in HbF resulting from the HMIP is 13.5%; that resulting from the BCL11A polymorphism is 6.4%. To identify the functional variant in HMIP, we used 1000 Genomes Project data, single nucleotide polymorphism imputation, comparisons of association results across populations, potential transcription factor binding sites, and analysis of phylogenetic conservation. Based on these studies, a hitherto unreported association between HbF expression and a 3-bp deletion, between 135 460 326 and 135 460 328 bp on chromosome 6q23 was found. This 3-bp deletion is in complete linkage disequilibrium with rs9399137, which is the single nucleotide polymorphism in HMIP most significantly associated with HbF among Chinese, Europeans, and Africans. Chromatin immunoprecipitation assays confirmed erythropoiesis-related transcription factors binding to this region in K562 cells. Based on transient expression of a luciferase reporter plasmid, the DNA fragment encompassing the 3-bp deletion polymorphism has enhancer-like activity that is further augmented by the introduction of the 3-bp deletion. This 3-bp deletion polymorphism is probably the most significant functional motif accounting for HMIP modulation of HbF in all 3 populations.


Subject(s)
Chromosomes, Human, Pair 6/genetics , Fetal Hemoglobin/genetics , Genes, myb , Sequence Deletion , Adult , Asian People/genetics , Base Sequence , Cohort Studies , DNA Mutational Analysis , DNA Primers/genetics , DNA, Intergenic , Enhancer Elements, Genetic , Female , Gene Expression , Genome-Wide Association Study , Heterozygote , Hong Kong , Humans , K562 Cells , Linkage Disequilibrium , Male , Molecular Sequence Data , Polymorphism, Single Nucleotide , Quantitative Trait Loci , beta-Thalassemia/blood , beta-Thalassemia/genetics
11.
Article in English | MEDLINE | ID: mdl-36767942

ABSTRACT

Iron deficiency (ID) is a prevalent nutritional deficiency affecting children/adolescents worldwide. We reported (1) the prevalence of ID and ID with anemia (IDA) among Chinese school-aged adolescents, (2) clinical and dietary predictors of iron status, and (3) its impact on health-related qualities of life (HRQoL). This cross-sectional study recruited 183 boys and 340 girls (mean age = 17.55) from 16 schools in Hong Kong. ID is defined as serum ferritin <15 µg/L. The participants reported their dietary habits, menstrual patterns (girls), and HRQoL using structured questionnaires. The overall prevalence of ID was 11.1%. None of the boys had ID or IDA. Among girls, the rate of ID was 17.1% and IDA was 10.9%. One-third (36.3%) reported a regular habit of skipping ≥1 meal/day. Lower ferritin was found in adolescents who skipped meals (Est = -35.1, p = 0.017). Lower ferritin is correlated with poorer school functioning (Est = 0.81, p = 0.045) and fatigue (Est = 0.92, p = 0.016). Skipping meals is associated with poorer physical (p = 0.0017) and school functioning (p = 0.027). To conclude, 1 in 10 school-aged adolescents in Hong Kong are iron-deficient. The ID rate in girls (17.1%) is similar to that in other industrialized countries (5.2-16.6%). Future work should promote awareness on the potential health consequences of poor dietary habits on ID and the well-being of adolescents.


Subject(s)
Anemia, Iron-Deficiency , Iron Deficiencies , Male , Child , Female , Humans , Adolescent , Anemia, Iron-Deficiency/epidemiology , Hong Kong/epidemiology , Quality of Life , Prevalence , Cross-Sectional Studies , Iron , Ferritins
12.
Stem Cells ; 27(6): 1463-8, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19492298

ABSTRACT

This study characterized the contribution of bone marrow-derived cells to human neoplasia and the perineoplastic stroma. The Australasian Bone Marrow Transplant Recipient Registry was used to identify solid organ neoplasia that developed in female recipients of male allogeneic stem cell transplants. Eighteen suitable cases were identified including several skin cancers, two gastric cancers, and one rectal adenoma. Light microscopy, fluorescence and chromogenic in situ hybridization, and immunohistochemistry were performed to determine the nature and origin of the neoplastic and stromal cells. In contrast to recent reports, donor-derived neoplastic cells were not detected. Bone marrow-derived neoplasia-associated myofibroblasts, however, were identified in the rectal adenoma and in a gastric cancer. Bone marrow-derived cells can generate myofibroblasts in the setting of human gastrointestinal neoplasia.


Subject(s)
Fibroblasts/pathology , Gastrointestinal Neoplasms/pathology , Hematopoietic Stem Cell Transplantation/adverse effects , Neoplasms, Second Primary/pathology , Bone Marrow Transplantation/adverse effects , Female , Humans , Immunohistochemistry , In Situ Hybridization, Fluorescence , Male , Stromal Cells/pathology , Transplantation, Homologous
14.
Am J Hematol ; 84(9): 603-6, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19650141

ABSTRACT

The b-globin gene LCR is located approximately 6 kb upstream of the embryonic epsilon-globin gene, and is made up of five DNase I hypersensitive sites (HSs), HS 1-5. LCR plays a pivotal role in regulating the expression of downstream epsilon-, (G)gamma-, (A)gamma-, delta-, and beta-globin genes in cis [1]. Deletions removing the LCR and parts of the downstream beta-globin gene cluster in patients have been described [2]. These individuals present with a (gammadeltabeta)0-thalassemia carrier phenotype. We now report two patients with severe sickle cell disease who were compound heterozygous for Hb S mutation and novel LCR deletion. In one case, HS 1-3 were deleted; in the other, HS 1-5 were deleted. In both cases, the b-like globin genes in cis to the LCR deletions were intact. Genotypically, both patients appeared to have sickle cell trait. Coinherited with either LCR deletion, these individuals presented as sickle cell disease patients. The breakpoints of these LCR deletions were defined. These results affirm that HS 2 and 3 are primarily responsible for conferring erythroid specific high-level expression of cis-linked beta-like globin genes. Furthermore, LCR deletions might cause hemolytic disease of newborns.


Subject(s)
Anemia, Sickle Cell/genetics , Hemoglobin, Sickle/genetics , beta-Globins/genetics , Adolescent , Child , Female , Heterozygote , Humans , Male , Multigene Family , Sequence Deletion
15.
Blood Cells Mol Dis ; 41(3): 255-258, 2008.
Article in English | MEDLINE | ID: mdl-18691915

ABSTRACT

Increased HbF levels or F-cell (HbF containing erythrocyte) numbers can ameliorate the disease severity of beta-thalassemia major and sickle cell anemia. Recent genome-wide association studies reported that single nucleotide polymorphisms (SNPs) in BCL11A gene on chromosome 2p16.1 were correlated with F-cells among healthy northern Europeans, and HbF among Sardinians with beta-thalassemias. In this study, we showed that SNPs in BCL11A were associated with F-cell numbers in Chinese with beta-thalassemia trait, and with HbF levels in Thais with either beta-thalassemia or HbE trait and in African Americans with sickle cell anemia. Taken together, the data suggest that the functional motifs responsible for modulating F-cells and HbF levels reside within a 3 kb region in the second intron of BCL11A.


Subject(s)
Carrier Proteins/genetics , Fetal Hemoglobin/genetics , Hemoglobinopathies/genetics , Nuclear Proteins/genetics , Quantitative Trait Loci , Black or African American/genetics , Anemia, Sickle Cell/genetics , Anemia, Sickle Cell/metabolism , Asian People/genetics , Fetal Hemoglobin/metabolism , Hemoglobinopathies/metabolism , Humans , Introns , Polymorphism, Single Nucleotide , Repressor Proteins , Thailand , beta-Thalassemia/genetics , beta-Thalassemia/metabolism
17.
Am J Hematol ; 83(6): 458-64, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18266208

ABSTRACT

Enhanced fetal hemoglobin (Hb F) production can partially compensate for the lack of adult hemoglobin (Hb A) in patients with beta-thalassemia major or intermedia, and ameliorate the clinical severity of these diseases. To further elucidate factors governing Hb F levels, we evaluated demographic, clinical, laboratory, and genetic characteristics in 241 unrelated adult beta-thalassemia carriers in Hong Kong. They had wide variations in Hb F and F-cell numbers skewing toward higher levels. Individuals who coinherited the Xmn IT-allele in the (G)gamma-globin gene promoter had higher Hb F and more F-cells compared with those lacking the Xmn I T-allele. However, both groups exhibited a similarly wide spread of Hb F and F-cells. The correlation of Hb F and F-cells corresponded well to both linear and exponential models, suggesting multiple mechanisms for Hb F augmentation. The heritabilities of Hb F and F-cells were calculated in 66 families (111 parents who were beta-thalassemia carriers and 82 asymptomatic offspring) to be 0.7 to 0.9. The Xmn I polymorphism accounted for 9% of the Hb F and 13% of the F-cell heritabilities. These results suggest that these family members are well suited for genome wide association studies that will identify genetic loci regulating Hb F production, and likely novel pharmacological targets for reactivating Hb F production in adults.


Subject(s)
Fetal Hemoglobin/analysis , beta-Thalassemia/genetics , Deoxyribonucleases, Type II Site-Specific , Family Health , Heterozygote , Hong Kong/epidemiology , Humans , Inheritance Patterns , Middle Aged , Mutation , Polymorphism, Genetic , Promoter Regions, Genetic , beta-Thalassemia/blood , beta-Thalassemia/epidemiology
20.
Sci Adv ; 1(8): e1500221, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26601252

ABSTRACT

Fms-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD) is frequently detected in acute myeloid leukemia (AML) patients and is associated with a dismal long-term prognosis. FLT3 tyrosine kinase inhibitors provide short-term disease control, but relapse invariably occurs within months. Pim protein kinases are oncogenic FLT3-ITD targets expressed in AML cells. We show that increased Pim kinase expression is found in relapse samples from AML patients treated with FLT3 inhibitors. Ectopic Pim-2 expression induces resistance to FLT3 inhibition in both FLT3-ITD-induced myeloproliferative neoplasm and AML models in mice. Strikingly, we found that Pim kinases govern FLT3-ITD signaling and that their pharmacological or genetic inhibition restores cell sensitivity to FLT3 inhibitors. Finally, dual inhibition of FLT3 and Pim kinases eradicates FLT3-ITD(+) cells including primary AML cells. Concomitant Pim and FLT3 inhibition represents a promising new avenue for AML therapy.

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