Photorefractive keratectomy for myopia.
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Animals↗
Biomedical subjects
H K Wu
Publications and source records attributed to H K Wu.
Glaucoma with inflammatory precipitates on the trabecular meshwork: a report of Grant's syndrome with ultrasound biomicroscopy of precipitates.
BACKGROUND: The syndrome of inflammatory precipitates on the trabecular meshwork is a rare form of inflammatory glaucoma that was described by Chandler and Grant in 1968 and subsequently given the eponym Grant's syndrome. METHODS: We present two cases of elevated intraocular pressure associated with inflammatory precipitates on the trabecular meshwork in otherwise relatively quiet eyes, consistent with Grant's syndrome. We review the epidemiology, clinical features, and mechanism of this syndrome. In addition, we demonstrate the use of ultrasound biomicroscopy for imaging angle inflammatory precipitates. RESULTS: Our patients demonstrate the cardinal features of Grant's syndrome, including acute onset, significant elevation of tension, trabecular meshwork precipitates in an otherwise quiet eye, limited response to typical pressure lowering agents, excellent response to topical steroids, evidence of recurrence with bilaterality, and systemic association with sarcoidosis. Ultrasound biomicroscopy proves to be a useful adjunct for pathologic imaging. CONCLUSIONS: The syndrome of glaucoma with inflammatory precipitates on the trabecular meshwork is a rare entity that should be considered as a possible diagnosis of elevated intraocular pressures in otherwise apparently quiet eyes.
Female↗
A structurally abnormal breakpoint cluster region gene in a transcription factor, hLH-2-negative human leukemia cell line.
hLH-2, a transcription factor that contains double cysteine rich regions (LIM motifs) and a homeobox (Hox) DNA-binding domain shows aberrant high expression in all cases of chronic myelogenous leukemia (CML). This gene has been mapped to the chromosome 9q33-34.1, the same region as the reciprocal translocation that creates the breakpoint cluster region (BCR)-ABL chimera of the Philadelphia chromosome (Ph'). To investigate the possible involvement between the BCR-ABL fusion gene and hLH-2 in the pathogenesis of CML, an hLH-2-negative CML cell line, JK-1 that carries double Ph' chromosomes, was examined. Like other CML cells, high BCR-ABL fusion mRNA levels are expressed, but no transcript of hLH-2 was detected in JK-1 cells as determined by reverse transcriptase-polymerase chain reaction (RT-PCR). Compared with the CML cell line, K-562, an additional rearrangement of the BCR gene was observed in JK-1 as determined by Southern blot hybridization; however, the hLH-2 gene was normal. These findings raise interesting questions about the possible roles of either the abnormal BCR gene or other genetic events such as the complex chromosomal abnormalities that result in hLH-2 being turned off in JK-1 cells.
Base Sequence↗
BamHI and HindIII repetitive DNA families in the rice genome.
In this paper we describe a novel method of cloning representative members of different repetitive DNA families based on the screening of a rice (Oryza sativa) genomic library using DNA from different C0t fractions as probes. Two genomic clones, which represent two different repetitive DNA families in rice, were isolated by this method and have been characterized. Their nucleotide sequences, copy numbers, distributions in major rice genome types, methylation patterns, and chromosomal localizations were determined.
Base Sequence↗
Differential expression of a basic helix-loop-helix phosphoprotein gene, G0S8, in acute leukemia and localization to human chromosome 1q31.
A basic helix-loop-helix phosphoprotein gene, G0S8, was recently isolated by differential screening of cDNA from human blood mononuclear cells stimulated with a T cell mitogen and cycloheximide. In this study, G0S8 expression was examined in normal and malignant hematopoietic cells by Northern blot analysis and reverse transcription-polymerase chain reaction (RT-PCR). G0S8 expression was observed in most fresh samples of acute myelogenous leukemia (AML) (28/30) and most cases of adult acute lymphoblastic leukemia (ALL) (9/11) regardless of clinical classification. G0S8 mRNA was also detected in all cases tested of chronic myelogenous leukemia (CML) in blast crisis. However, G0S8 expression was not detected in CML patients in chronic phase, nor in normal bone marrow or other hematopoietic cells. G0S8 has been mapped using fluorescence in situ hybridization (FISH) to human chromosome 1q31, the same site reported for the B cell homolog BL34/1R20 and within a region implicated in the development of hematological malignancies. The consistent observation of G0S8 mRNA in patient samples of acute leukemia suggests that G0S8 expression may either play a role in leukemogenesis or represent a common consequence of dysregulated growth.
Amino Acid Sequence↗
Circulating late-stage erythroid progenitors in a patient with agnogenic myeloid metaplasia.
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Erythroid Precursor Cells↗
Effect of stem cell factor (c-kit ligand) on clonogenic leukemic precursor cells: synergy with other hematopoietic growth factors.
Using clonogenic assay we investigated the effect of stem cell factor (SCF) on the in vitro growth of clonogenic precursor cells from acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) in the presence or absence of recombinant human erythropoietin (rhEpo) or recombinant human granulocyte colony-stimulating factor (rhG-CSF). SCF as a single factor did not induce significant colony formation, and even in the presence of rhEPO or rhG-CSF it very weakly stimulated erythroid colony formation and was rarely capable of inducing myeloid colony formation by clonogenic leukemic cells. In culture dishes supplemented with SCF, both myeloid and erythroid colony formations were dramatically enhanced in MDS, regarding both colony number and size. Colony-formation abilities by MDS progenitors were improved following costimulation with SCF and rhEpo. These results suggest that SCF may have a therapeutic role in restoring hematopoiesis in patients with MDS.
Acute Disease↗
Expression of alpha-amylases, carbohydrate metabolism, and autophagy in cultured rice cells is coordinately regulated by sugar nutrient.
A rice suspension cell culture system has been established to study how sugar depletion regulates alpha-amylase expression, carbohydrate metabolism, and other physiological and cellular changes. It is shown here that a group of 44 kDa alpha-amylases are constitutively expressed whether or not the cells are starved of sucrose. However, expression of a new group of alpha-amylases of 46 kDa is dramatically induced when cells are starved of sucrose. Cellular sugar and starch were rapidly consumed and metabolic activity was decreased in the starved cells. Extensive autophagy also occurred in the starved cells, which caused an increase in vacuolar volume and degradation of cytoplasmic constituents including amyloplasts. Immunocytochemical studies revealed that alpha-amylases are localized in starch granules within amyloplasts, in cell walls, and in some of the vacuoles. The presence of putative signal sequences in the N-termini of nine rice alpha-amylases suggests hitherto unidentified pathways for import of alpha-amylases into amyloplasts. The studies show that differential alpha-amylase expression, carbohydrate metabolism, metabolic activity, and vacuolar autophagy are coordinately regulated by the sugar level in the medium. As the starved suspension cells exhibit some sugar-regulated characteristics of alpha-amylase expression in germinating rice embryos as well as physiological changes similar to those in senescing cells, this system represents an ideal tool for studying cellular, biochemical, and molecular biological aspects of alpha-amylase gene regulation, carbohydrate metabolism, senescence, and protein targeting in plants.
Amino Acid Sequence↗
Systemic (serum) soluble interleukin-2 receptor levels in corneal transplant recipients.
Elevated soluble interleukin-2 receptor levels (sIL-2R), a measure of T cell activation, have been used as a serum marker for early rejection in solid organ transplant patients. In this preliminary study, we measured sequential sIL-2R levels of 53 otherwise immunologically normal corneal transplant recipients. Eleven of these transplants rejected; sIL-2R was significantly elevated during the acute rejection episode, compared to pre-rejection and post-rejection levels (p = 0.01). Five patients' sIL-2R rose one to nine months prior to rejection. These data indicate that sIL-2R levels may correlate with corneal graft rejection and may be predictive of impending rejection. A larger prospective study with many immunologically normal patients and careful monitoring of sIL-2R levels prior to and during the acute rejection episode will be necessary to determine the value of sIL-2R monitoring as a predictive tool for corneal graft rejection.
Acute Disease↗
Anti-tumor effects of interleukin-4 and interleukin-5 against mouse B cell lymphoma and possible mechanisms of their action.
We investigated the anti-tumor effects of recombinant mouse interleukin (IL)-4 and IL-5 by using a transplantable B cell lymphoma 38C13 cell line as a model. Daily local administration of either IL-4 or IL-5 produced moderate but significant inhibition of the rate of local tumor growth and prolongation of mean survival time (MST) in syngeneic C3H/HeJ mice; these anti-tumor effects appeared to plateau at low doses. Histopathologic and immuno-histochemical examination revealed necrotic changes in the cytokine-treated tumors, associated with infiltration of inflammatory cells such as eosinophils, macrophages, and lymphocytes. The infiltrating lymphocytes were found to be Thy-1.2+ T cells. To elucidate the importance of T cells, the rate of tumor growth and the MSTs were compared between athymic T cell-deficient BALB/c nude mice and immunocompetent C3H/HeJ mice. In the nude mice the transplanted tumor grew more rapidly and the MST was shorter than in the normal mice, suggesting a significant contribution of infiltrating T cells in the anti-tumor effects of the interleukins. Lastly, in vitro, growth inhibition of the 38C13 cells was observed in a dose-dependent manner at relatively high concentrations of either cytokine. Therefore, we conclude that both IL-4 and IL-5 have moderate anti-tumor effects against 38C13 B cell lymphoma both in vivo and in vitro, and that the observed in vivo anti-tumor effects are probably mediated both by tumoristatic action of infiltrating cells, such as eosinophils, macrophages and T lymphocytes, and by direct anti-proliferative action of the recombinant cytokines.
Animals↗
Cytogenetic analysis of bone marrow from patients with primary myelodysplastic syndrome.
Of 34 patients with primary myelodysplastic syndrome (MDS), 26 (76.5%) were found to have chromosome defects using an improved bone marrow culture method and high-resolution G-banding technique induced by actinomycin D. The frequency of abnormalities varied among the subtypes: 1/2 in refractory anaemia with ringed sideroblasts; 18/24 in refractory anaemia; 5/6 in refractory anaemia with excess of blasts (RAEB); and 2/2 in refractory anaemia with excess of blasts in transformation. The most frequent abnormalities, either single, double or complex defects, were -5/5q-, -7, +8 and +21; 16q-/16p-, +19 and -X were also common. The percentage of aneuploid cells, in particular hypodiploid cells, was increased. The abnormalities were detected more frequently in complex aberrations associated with RAEB and RAEB in transformation. The presence of -5/5q- as a sole aberration was associated with longer mean survival time (greater than 18 months) but multiple (more than two) chromosomal abnormalities were associated with a poorer prognosis and a mean survival time of only 7.5 months. Chromosome follow-up studies indicated that patients with -7, +8, +21, -X and complex defects, increased hypodiploid cells and karyotpic evolution were likely to have a high risk of transformation to leukaemia or to a more severe subtype of MDS with a short overall mean survival time. These defects, mostly of the deleted type, are assumed to play a specific role in the pathogenesis of myelodysplasia. Repeated chromosomal analyses during the clinical course convey more accurate prognostic criteria for patients.
Adolescent↗
Localization of specific repetitive DNA sequences in individual rice chromosomes.
This paper describes the characterization and chromosomal distribution of three different rice (Oryza sativa) repetitive DNA sequences. The three sequences were characterized by sequence analysis, which gave 355, 498 and 756 bp for the length of the repeat unit in Os48, OsG3-498 and OsG5-756, respectively. Copy number determination by quantitative DNA slot-blot hybridization analysis showed 4000, 1080 and 920 copies, respectively, per haploid rice genome for the three sequences. In situ DNA hybridization analysis revealed that 95% of the silver grains detected with the Os48 probe were localized to euchromatic ends of seven long arms and one short arm out of the 12 rice chromosomes. For the OsG3-498 repetitive sequence, the majority of silver grains (58%) were also clustered at the same chromosomal ends as that of Os48. The minority (28%) of silver grains were located at heterochromatic short arms and centromeric regions. For the OsG5-756 repetitive sequence, 81% of the silver grains labeled the heterochromatic short arms and regions flanking all of the 12 centromeres. Thus, each of these three repetitive sequences was distributed at specific defined chromosomal locations rather than randomly at many chromosomal locations. The approximate copy number of a given repetitive DNA sequence at any specific chromosomal location was calculated by combining the information from in situ DNA hybridization analysis and the total copy number as determined by DNA slot-blot hybridization.
Base Sequence↗
Significance of liver biopsy in the diagnosis of infectious hepatitis in children.
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Biopsy↗
A case of extra-hepatic portal vein aneurysm: evaluation by 3-dimensional computerized tomography angiogram.
Portal vein aneurysms (PVAs) are rare lesions associated with congenital vascular anomalies or chronic portal hypertension. Although usually benign, they occasionally lead to complications such as aneurysmal rupture, porto-systemic shunts, mural thrombosis in the portal vein, and compression of the biliary tract. So far, the diagnosis of these lesions has been dependent on 2-dimensional imaging modalities such as computed tomography (CT) or magnetic resonance imaging (MRI), or invasive procedures such as percutaneous transhepatic portography. Here we present the first documented case of an extra-hepatic portal vein aneurysm evaluated by 3-dimensional CT angiography. This easily performed and accurate imaging technique may obviate the need for invasive angiographic procedures in the future for the 3-dimensional characterization of deep vascular malformations in the portal circulation.
Adult↗