1476
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Zhang J, Weng XZ, Ma L. [Changes of immunologic function in patients with COPD induced chronic cor pulmonale]. ZHONGHUA NEI KE ZA ZHI 1993; 32:746-9. [PMID: 8137654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We determined the counts of lymphocyte subpopulation CD3+, CD4+, CD8+ and CD16+ in PBL by using APAAP method and some humoral immunological parameters (HIP) in patients with COPD induced chronic cor pulmonale. The results showed: (1) In cases during exacerbation stage, the counts of CD3+, CD4+, CD16+ and the CD4+:CD8+ ratio decreased remarkably (P < 0.001). There was significant correlation between the counts of CD3+, CD4+, the CD4+:CD8+ ratio and PaO2 (P < 0.01). No marked change in serum IgG, IgA and IgM level was observed. Serum IgE and CIC level was significantly higher and C3 level lower than those in controls (P < 0.01). After treatment the counts of CD3+, CD4+, CD16+ and the CD4+:CD8= ratio went up notably (P < 0.01), but no significant change was found in the HIP. (2) In cases during remission stage only the CD4+ level was low (P < 0.05) and no remarkable difference was observed in the HIP. After treatment with thymopeptide the counts of CD4+ increased (P < 0.05), CD8+ decreased (P < 0.01) and the CD4+:CD8+ ratio increased (P < 0.01). The serum IgA and CIC level also went up significantly (P < 0.05). This indicated that thymopeptide played a role in regulating the immunologic function.
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1477
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Chan AC, Lorentz TG, Ma L, Cheung AN, Tse SK. Fine-needle aspiration of cutaneous malakoplakia. Diagn Cytopathol 1993; 9:576-80. [PMID: 8287771 DOI: 10.1002/dc.2840090522] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A 99-yr-old Chinese woman with cutaneous malakoplakia and concomitant urinary tract infection was reported. The patient presented with an ulcerated right lower quadrant mass and computerized tomography showed that it was limited to the skin and subcutaneous tissue with no extension to the pelvic or abdominal structures. The patient also suffered from urinary tract infection and was treated with oral norfloxacin. The ulcerated subcutaneous mass disappeared on follow-up visit 6 months after presentation. The cytologic (fine-needle aspiration), histologic (trucut biopsy) and ultrastructural features of cutaneous malakoplakia were described. The possible usefulness of fine-needle aspiration in the diagnosis of this condition was discussed.
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1478
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Lee AC, Kwong YI, Fu KH, Chan GC, Ma L, Lau YL. Disseminated mediastinal carcinoma with chromosomal translocation (15;19). A distinctive clinicopathologic syndrome. Cancer 1993; 72:2273-6. [PMID: 8374886 DOI: 10.1002/1097-0142(19931001)72:7<2273::aid-cncr2820720735>3.0.co;2-u] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND A case of disseminated mediastinal carcinoma probably of thymic origin is reported in a 5-year-old boy with an anterior mediastinal mass associated with superior vena cava obstruction, tracheal deviation, right malignant pleural effusion, and evidence of bone metastasis. The diagnosis was based on findings of radiologic localization, light and electron microscopic study, and immunohistochemistry. The patient received combination chemotherapy but died of progressive disease. METHODS Cytogenic study on the pleural fluid was attempted, and a literature search for similar chromosomal aberration was performed. RESULTS Cytogenetic study of tumor cells from the pleural fluid revealed a clonal chromosomal abnormality of t(15;19)(q12;p13.1). Two patients with similar disease were reported in the English literature; their clinical courses, immunohistochemical findings, and t(15;19) were almost identical to those of the patient reported in this study. CONCLUSION The authors suggest that this translocation may be specific to thymic carcinoma and may indicate a particularly aggressive form of the disease. Carcinomas are rare in children, so the chromosomal translocation may serve as a helpful marker for the diagnosis.
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1479
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Ma L. Evidence for nitric oxide-generator cells in the brain. THE BULLETIN OF TOKYO MEDICAL AND DENTAL UNIVERSITY 1993; 40:125-34. [PMID: 7691425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Nitric oxide (NO) is a free radical that has been recently recognized as a neuronal messenger molecule. In order to understand the way in which NO functions in the central nervous system (CNS), it is important to identify the NO-generator and NO-target cells in the brain. I measured firstly the distribution of NO synthase in the brain, which catalyzes L-arginine to form NO, by the measurement of citrulline formation that is also synthesized from L-arginine together with NO in equal molar bass. In the brain of adult rat, the most potent activity of NOS was apparent in the cerebellum, next in the olfactory bulb and medium in the cerebrum. Further, in the presence of NADPH and Ca2+, NOS activity was detected in the neuron cultures derived from the cerebrum of fetal rat. Astrocytes, one type of glia, prepared also from the cerebrum of fetal rat, appeared to have a small but significant NOS activity. As astrocytes possess a high amount of cytosolic guanylate cyclase that is known to be activated by NO, the changes in the intracellular cGMP levels in the astrocytes were measured as another index of NO formation. The treatment of astrocytes with NOS inhibitor caused the suppression of the intracellular cGMP levels. These results indicate that NO is definitely produced by astrocytes. In addition, in the blood vessel system of the brain, although NOS has been thought to be localized in the endothelial cells of only larger vessels, NOS activity was also observed in the microvessel endothelial cells of the cerebrum of both adult and fetal pig. These data suggest that neuronal cells may be the major site of NO generation in the brain, and that the NOS is a constitutive type. The data also suggest that astrocytes can also express constitutive NOS, although the potency is not so large. Microvessel endothelial cells of the brain are also one of the sources of NO. The NO produced by these cells increases the cGMP levels in the astrocytes and may affect some physiological and/or pathophysiological events in the brain.
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1480
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Gan L, Chew C, Lye I, Ma L, Li G. Effect of water-soluble cosurfactants on microemulsion polymerization of styrene. POLYMER 1993. [DOI: 10.1016/0032-3861(93)90511-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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1481
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Guo JX, Pan J, Ma L, Chen MZ, Xu H, Shi AY. Experimental studies of laser myocardial revascularization in rats. Chin Med J (Engl) 1993; 106:665-7. [PMID: 8287700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Myocardial revascularization by Nd: YAG laser used in rats with myocardial infarction was studied. The left coronary artery was ligated and the laser channels with a diameter of 300 microns were made immediately by 2.5-4.2 W lasersonics YAG unit. After 24 hours, the rats were killed. Evaluation included hemodynamics, lactate dehydrogenase of myocardium and myocardial infarct size. The results showed that laser myocardial revascularization reduced myocardial infarct size and enzyme leakage, and improved left ventricular function. The study may provide theoretical basis for the clinical applications of this new technique in the treatment of ischemic heart disease.
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1482
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Bell JR, Noveen A, Liu YH, Ma L, Dobias S, Kundu R, Luo W, Xia Y, Lusis AJ, Snead ML. Genomic structure, chromosomal location, and evolution of the mouse Hox 8 gene. Genomics 1993; 17:800. [PMID: 7902329 DOI: 10.1006/geno.1993.1417] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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1483
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Allen RD, Ma L, Fok AK. Acidosomes: recipients of multiple sources of membrane and cargo during development and maturation. J Cell Sci 1993; 106 ( Pt 1):411-22. [PMID: 8270639 DOI: 10.1242/jcs.106.1.411] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acidosomes are organelles that in Paramecium are responsible for the acidification of phagosomes before phagosomes fuse with lysosomes. Using a combination of (a) the quick-freeze deep-etch (QF-DE) technique, (b) monoclonal antibodies (mAbs) that label specific membrane pools including those of the acidosomes, and (c) horseradish peroxidase (HRP)-uptake studies, we followed the development of acidosomes from the Golgi complex as well as the rapid transfer of HRP into the acidosomes. We also studied some of the characteristics of the involved membrane pools. Morphologically, acidosomes were first detected in the cytosol near the ER and Golgi stacks as clumps of tubules and vesicles, which apparently coalesced to form larger spherical or elongated preacidosomes. These clumped vesicles and preacidosomes had a QF-DE morphology resembling that of the mature acidosomes and were specifically labeled with mAbs that also labeled mature acidosomes. Within 10 s HRP cargo could be internalized by acidosomes while they were docked at the nascent vacuole membrane. This rapid uptake of HRP along with membrane occurs by vesicle fusion, a conclusion supported by QF-DE images. Thus the acidosome obtains its membrane from at least two sources, from the trans-Golgi network, and from the small HRP-containing vesicles. Cargo can also be acquired from two sources, the Golgi apparatus and the transport vesicles. Since it acquires non-particulate exogenous marker we conclude that the acidosome is linked to the endocytic pathway.
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1484
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Yuan J, Angelucci E, Lucarelli G, Aljurf M, Snyder LM, Kiefer CR, Ma L, Schrier SL. Accelerated programmed cell death (apoptosis) in erythroid precursors of patients with severe beta-thalassemia (Cooley's anemia). Blood 1993; 82:374-7. [PMID: 8329696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The profound and life-threatening anemia in patients with Cooley's anemia is ascribed primarily to intramedullary hemolysis (ineffective erythropoiesis), the cause of which is obscure. Based on prior morphologic data showing nuclear abnormalities, we hypothesized that accelerated apoptosis could occur in these erythroid precursors. The highly successful bone marrow (BM) transplantation program for patients with Cooley's anemia provided us with a unique opportunity to test this hypothesis. We obtained pretransplantation BM aspiration samples from patients undergoing BM transplantation in Pesaro, Italy and from their allogeneic donors. The erythroid precursors were isolated using ficoll sedimentation and then panning selecting fro CD45- cells. Cytospin and Giemsa staining showed that the separation provided greater than 90% erythroblasts. Five million of these erythroblasts were lysed and their DNA was isolated. There were obvious ladder patterns of DNA breakdown products in beta-thalassemia major samples, with less occurring in beta-thalassemia trait. Normal individuals showed only a slight smear of breakdown of DNA. These results indicate there is enhanced apoptosis in the erythroblasts in the BMs of Cooley's anemia patients. This finding might partially explain why most of these erythroblasts never survive to become mature erythrocytes.
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1485
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Cao X, Ben K, Ma L, Wang Y, Chen Y, Zhou H. Secretory monoclonal IgA antibody to human sperm produced by gastrointestinal immunization inhibits human sperm activity and mouse in vitro fertilization. J Reprod Immunol 1993; 24:13-28. [PMID: 8350303 DOI: 10.1016/0165-0378(93)90033-e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BALB/c mice were immunized intragastrically with human sperm. Cells from the Peyer's patches and spleens of the immunized mice were for the preparation of hybridomas secreting antisperm monoclonal IgA (mcIgA). The specific ratio of IgA-secreting cells in Peyer's patches was much higher than that in spleen. The binding site on human sperm of 9 of 19 mcIgA was in the post-acrosomal region using an immunofluorescent assay. Two of eight selected mcIgA caused strong human sperm agglutination and three of them produced significant inhibition of mouse in vitro fertilization. No mcIgA tested caused obvious human sperm immobilization or inhibited mouse in vivo fertilization. In vitro assembly of selected mcIgA in ascites with mouse secretory component (SC) caused no significant changes in effects on sperm function and in vitro fertilization. By use of Western blotting, dimer or higher polymers were demonstrated in all selected mcIgAs and corresponding protein antigens in 6 of 8 selected mcIgAs. These results suggest that human sperm function may be inhibited and fertilization rate reduced by specific secretory IgA to human sperm and that secretory immunity to protein antigens of human sperm could be induced by intragastrointestinal immunization.
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1486
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Bell JR, Noveen A, Liu YH, Ma L, Dobias S, Kundu R, Luo W, Xia Y, Lusis AJ, Snead ML. Genomic structure, chromosomal location, and evolution of the mouse Hox 8 gene. Genomics 1993; 16:123-31. [PMID: 8098007 DOI: 10.1006/geno.1993.1149] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We isolated genomic clones containing the mouse Hox 8 gene, a member of the msh gene family. We show that Hox 8 comprises two exons of approximately 600 and 691 bp separated by a 3.5-kb intron, and that it cosegregates with previously mapped markers in the distal region of mouse chromosome 13. In midgestation embryos, the Hox 8 gene produces transcripts of 1.4 and 2.2 kb. Both transcripts are present in facial tissues of the newborn mouse, though the ratio of the 2.2-kb transcript to the 1.4-kb transcript is reduced relative to the ratio observed for midgestation embryos. An alignment of the homeobox sequences of previously characterized members of the msh family revealed three subclasses: Hox 7-like genes, Hox 8-like genes, and msh-like genes. Both the Hox 7-like genes and Hox 8-like genes are present throughout the vertebrates. Representatives of the third subclass, the msh-like genes, are found in a protostome (Drosophila) and a deuterostome (Ciona) and are thus likely to be phylogenetically widespread. To investigate the distribution of Hox 8-like genes outside the chordates, we used the polymerase chain reaction and degenerate Hox 8 primers to screen genomic DNA of the purple sea urchin (Strongylocentrotus purpuratus, Phylum Echinodermata). We isolated a gene with greater sequence similarity to mouse Hox 8 than to members of the Hox 7 or msh subfamilies, demonstrating that the Hox 8 subfamily has been in existence at least since the echinoderms diverged from the lineage that gave rise to the chordates.(ABSTRACT TRUNCATED AT 250 WORDS)
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1487
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Yuen KY, Ma L, Wong SS, Ng WF. Fatal necrotizing fasciitis due to Vibrio damsela. SCANDINAVIAN JOURNAL OF INFECTIOUS DISEASES 1993; 25:659-61. [PMID: 8284652 DOI: 10.3109/00365549309008557] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A patient who succumbed to fulminant necrotizing fasciitis due to Vibrio damsela after injury by a rabbitfish is described. Despite the absence of any known underlying illness, he did not respond to appropriate antibiotic therapy and radical surgical intervention. This represents the first documented case of necrotizing fasciitis due to this organism, and is also the first reported case in Southeast Asia inflicted by rabbitfish.
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1488
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Ma L, Cao SG, Yan BX, Zuo HT, Ding ZT, Meng QF, Cheng YH. Induced rebuilding of aspartase conformation. Ann N Y Acad Sci 1992; 672:60-5. [PMID: 1476390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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1489
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Pittaluga S, Loke SL, So KC, Cheung KN, Ma L. Clonal Epstein-Barr virus in lymphoepithelioma-like carcinoma of the stomach: demonstration of viral genome by in situ hybridization and Southern blot analysis. Mod Pathol 1992; 5:661-4. [PMID: 1369803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
Lymphoepithelioma (LE), originally described in the nasopharynx, is an undifferentiated carcinoma with heavy lymphocytic infiltrate. The tumor is common in Southeast Asia, particularly in southern China, where the Epstein-Barr virus (EBV) association has been documented more consistently than in Western countries. Tumors histologically similar to LE have been described also in other anatomical sites, mostly of fore-gut origin, such as salivary gland, tonsil, lung, thymus, and more recently stomach. We are reporting a case of poorly differentiated gastric adenocarcinoma with marked lymphocytic infiltrate resembling LE (LE-like carcinoma) in a Chinese without evidence of nasopharyngeal carcinoma. In situ hybridization for EBV revealed that the tumor cells but not the lymphoid cells harbored the virus. Tumor cells both in syncytial and glandular areas were positive for EBV. By Southern blot analysis EBV was demonstrated in the DNA extracted from the tumor, while the adjacent normal gastric tissue was negative. Moreover, analysis of the EBV termini revealed a clonal episomal form of the virus. Our case further supports the hypothesis that EBV is associated with LE-like gastric carcinoma. It also strongly suggests that EBV infection has preceded, and thus most likely contributed to, the clonal expansion in this tumor.
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1490
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Abstract
The purpose of this paper is to examine critically the evidence that atypical hyperplasia (AH) is a risk factor for breast cancer. First, we appraised studies that have examined the association between AH and breast cancer risk for their adherence to widely accepted standards for the conduct of research. Second, we examined the available evidence to determine the plausibility of an association between AH and breast cancer risk using the guidelines proposed by Bradford Hill. A total of 18 studies (11 cohort studies, two case-control studies, and five cross-sectional studies) were found that were published in the English language from January 1960 to March 1992 that examined the association of AH as a distinct entity and breast cancer risk. A systematic approach was adopted to examine the collected studies for their adherence to methodologic standards, which showed wide variation among studies. A meta-analysis was carried out, based on a total sample size of 182,980 women. Of 16 studies that gave point estimates of risk, 14 exceeded unity and 12 were significantly different from unity. The pooled estimate from all studies of the association between AH and breast cancer, gave an overall odds ratio (OR) of 3.67 (95 percent confidence interval = 3.16-4.26). The test of the hypothesis of homogeneous association was rejected (chi 2 = 151.6, df = 14, P < 0.0001), indicating significant variability among the ORs of individual studies. The conclusions from the application of the Bradford Hill criteria indicated strongly that AH is a risk factor for breast cancer.
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1491
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Ma L, Ramachandran C, Weiner ND. Bulk organic solvent-water systems as a possible model to predict alkyl p-aminobenzoate partitioning in liposomes. J Pharm Sci 1992; 81:1104-8. [PMID: 1447714 DOI: 10.1002/jps.2600811113] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This study compares the bilayer-water distribution coefficients of a homologous series of n-alkyl p-aminobenzoates in liposomes with their respective distribution coefficients in octanol-water, oleyl alcohol-water, and hexane-water systems. The data indicate that the bilayer-water distribution coefficient is quite sensitive to changes in solute structure and to the structural organization of the bilayer and that octanol, oleyl alcohol, and hexane are able to reflect the partitioning changes that occur in the liposomal bilayer with respect to increasing the alkyl chain length of n-alkyl p-aminobenzoates. For this particular homologous series, the hexane-water system tended to underestimate the bilayer-water distribution coefficients, whereas octanol-water and oleyl alcohol-water systems overestimated solute partitioning into the bilayer. The similarity of the lipid environment, with respect to solute partitioning, in the organic solvent system and that in liposomes can be ascertained by using the Collander relationship.
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1492
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Ma L, Spremulli LL. Immunological characterization of the complex forms of chloroplast translational initiation factor 2 from Euglena gracilis. J Biol Chem 1992; 267:18356-60. [PMID: 1526976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Euglena gracilis chloroplast translational initiation factor 2 (IF-2chl) occurs in several complex forms ranging in molecular mass from 200 to 800 kDa. Subunits of 97 to greater than 200 kDa have been observed in these preparations. Two monoclonal antibodies were prepared against the 97-kDa subunits of IF-2chl. Both of these antibodies recognize all of the higher molecular mass forms of this factor, suggesting that these subunits are closely related. Gel filtration chromatography indicates that the higher molecular mass subunits of IF-2chl are present in the higher molecular mass complexes, whereas the smaller subunits are present in the 200-400 kDa forms of IF-2chl. Probing extracts of light-induced and dark-grown cells with the antibodies indicates that the light induction of this chloroplast factor results from the synthesis of new polypeptide rather than from the activation of an inactive precursor form of the protein. Both the higher and lower molecular mass subunits of IF-2chl are present in 30 S initiation complexes as indicated by Western analysis. The binding of IF-2chl to chloroplast 30 S ribosomal subunits requires the presence of GTP, but does not require fMet-tRNA, messenger RNA, or other initiation factors. Neither polyclonal nor monoclonal antibodies against E. gracilis IF-2chl cross-react with Escherichia coli IF-2 or with animal mitochondrial IF-2.
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1493
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Beaty JA, Jones MM, Ma L. The reactions of cis-[Pt(NH3)2(H2O)2]2+ with L-(+)-cystathionine and seleno-L-methionine: potential relevance to the molecular basis of cisplatin toxicity. Chem Res Toxicol 1992; 5:647-53. [PMID: 1446004 DOI: 10.1021/tx00029a009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
NMR spectroscopic studies indicate that the hydrolysis product of cisplatin, cis-[Pt(NH3)2-(H2O)2]2+, reacts readily with the important intracellular thiol L-(+)-cystathionine and the amino acid derivative seleno-L-methionine. In both cases, the formation of six-membered mononuclear S,N- or Se, N-chelate rings was established on the basis of [1H], [13C], [77Se], [195Pt], and [13C]-(1H) DEPT (distortionless enhancement by polarization transfer), COSY (correlation spectroscopy), heterocorrelation, and NOE (nuclear Overhauser effect) difference NMR experiments. The formation of these products suggests that related in vivo processes may play a significant role in the toxicity of cisplatin. The potential loss of NH3 in such platinum complexes may lead to additional products over time.
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1494
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Ma L, Spremulli L. Immunological characterization of the complex forms of chloroplast translational initiation factor 2 from Euglena gracilis. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)36968-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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1495
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Beaty JA, Jones MM, Wilson DJ, Ma L. An in vitro model for the in vivo mobilization of cadmium by chelating agents using 113Cd-NMR spectroscopy. Chem Res Toxicol 1992; 5:568-75. [PMID: 1391624 DOI: 10.1021/tx00028a017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
An in vitro method, based on 113Cd-NMR spectroscopy, that provides an alternative to the use of animals for an initial screening of cadmium antagonists is presented. The relative values of the effective stability constants of potential chelating antagonists for cadmium are estimated by using 113Cd-NMR spectroscopy to determine the concentrations of the cadmium species involved in appropriate competitive equilibria. This is accomplished via an examination of the competition between the proposed antagonist and EDTA (ethylenediaminetetraacetic acid) for cadmium-113; previously, EDTA has been shown to be capable of removing cadmium from such in vivo binding sites as metallothionein. The reactions proceed via the stepwise addition of three dithiocarbamate groups to the cadmium accompanied by the concurrent stepwise release of donor groups from the EDTA. The resulting 113Cd-NMR data allow for the determination of the overall stability constant for the complex formed between cadmium and N-methyl-D-glucamine dithiocarbamate, iminodiacetic acid dithiocarbamate, proline dithiocarbamate, sarcosine dithiocarbamate. The use of 113Cd-NMR spectroscopy has the potential for providing direct evidence on the effectiveness of chelate antagonists to compete with endogenous ligands for other toxic metal ions. This technique could prove very useful for other compounds that are not stable enough toward acid and/or base to be examined by standard titrimetric methods.
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1496
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Yuen ST, Ng IO, Ho J, Ma L. Mesocolonic lymphangioma: a case report with immunoperoxidase and electron microscopic studies. Pathology 1992; 24:221-3. [PMID: 1437300 DOI: 10.3109/00313029209063179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A 14 yr old girl presented with a large cystic mass in the transverse mesocolon which was completely excised. Cystic lymphangioma was diagnosed, based on the specific histologic, immunoperoxidase and ultrastructural findings.
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1497
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Ma L, Fishell E, Wright B, Hanna W, Allan S, Boyd NF. Case-control study of factors associated with failure to detect breast cancer by mammography. J Natl Cancer Inst 1992; 84:781-5. [PMID: 1573665 DOI: 10.1093/jnci/84.10.781] [Citation(s) in RCA: 148] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Although mammography is widely used to detect breast cancer, it is recognized that not all cancers can be seen on mammographic images. PURPOSE Our purpose was to examine factors associated with failure to detect breast cancer by mammography. METHODS A case-control study was carried out in which subjects in whom histologically verified breast cancer was not detected by mammography (false negatives) were contrasted with subjects in whom breast cancer had been detected by mammography (true positives). Mammograms from individuals with histologically confirmed breast cancer were classified independently by two radiologists who were unaware of the clinical or other characteristics of the subjects. Histologic slides of all tumors were reviewed by one pathologist. RESULTS Three variables were found to be independently and significantly associated with failure to detect breast cancer by mammography. Breast cancer was less likely to be detected by mammography in the presence of extensive parenchymal densities (odds ratio [OR] = 9; 95% confidence interval [CI] = 1.8-44.3), a tumor of lobular histology (OR = 7; 95% CI = 2.2-22.1), and tumors of small size (OR = 0.10; 95% CI = 0.0-0.9). CONCLUSION Our results indicate that biologic factors are associated with failure to detect some breast cancers by mammography and indicate directions for future research in breast imaging.
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1498
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Brenner MC, Ma L, Johnson MK, Scott RA. Spectroscopic characterization of the alternate form of S-methylcoenzyme M reductase from Methanobacterium thermoautotrophicum (strain delta H). BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1120:160-6. [PMID: 1314088 DOI: 10.1016/0167-4838(92)90264-e] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Two forms (MR1 and MR2) of S-methylcoenzyme M reductase were purified from Methanobacterium thermoautotrophicum (strain delta H) as recently described (Rospert, S., Linder, D., Ellerman, J. and Thauer, R.K. (1990) Eur. J. Biochem. 194, 871-877). MR2 was at least 50-fold more active than MR1, independent of assay conditions. The two forms are spectroscopically similar, but not identical, by UV-visible, magnetic circular dichroism and resonance Raman spectroscopies. MR2 exhibited an EPR signal corresponding to 20% of the enzyme-bound nickel. Strong EPR signals similar to those previously assigned to Ni(I)F430 bound to methylreductase in Methanobacterium thermoautotrophicum (strain Marburg) (Albracht, S.P.J., Ankel-Fuchs, D., Bocher, R., Ellerman, J., Moll, J., Van der Zwann, J.W. and Thauer, R.K. (1988) Biochim. Biophys. Acta 955, 86-102) were observed in MR2-rich, log-phase, as well as in MR1-rich, slow-growing bacteria. Log-phase cells had dramatically different EPR spectra depending on whether they were removed from the fermenter (under gas flow) before or after cooling to 10 degrees C. EPR spectra of slow-growing cells were insensitive to harvesting conditions. The possible biological significance of the alternate form of methylreductase is discussed.
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1499
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He Y, Li R, Chen Q, Lin Z, Xia D, Ma L. [Chemical studies on immunologically active polysaccharides of Ganoderma lucidum(Leyss. ex Fr.) Karst]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1992; 17:226-8, 256. [PMID: 1418551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BN3B, the polysaccharide component of the fruit of Ganoderma lucidum, has been shown to have immune activity. From BN3B four homogeneous polysaccharides were separated and purified. Chemical studies on the main components BN3B1 and BN3B3 indicated that BM3B1 contained only glucose and should be a glucan containing beta-(1----6) and (1----3)glycoside bonds and that BN3B3 was an arabinogalactan containing beta-(1----6) and (1----3)glycoside bonds.
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1500
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Ma L. [Magnesium sulfate in prevention of preterm labor]. ZHONGHUA YI XUE ZA ZHI 1992; 72:158-61, 191. [PMID: 1319808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
To observe the efficacy of magnesium sulfate in the treatment of preterm labor, 65 uncomplicated cases of preterm labor between 28 and 36 weeks of gestation were studied prospectively during Sep. 1988-May 1991. They were divided into two groups randomly. 30 cases were treated with magnesium sulfate and 35 cases with barbiturates or bed rest. The prevention of delivery for at least 48 hours after the initiation of therapy was achieved in 23 of the 30 cases (76.67%) of the magnesium sulfate group and in 3 of the 35 cases (8.57%) in the control group. Delay of more than 7 days was achieved in 17 of the 30 cases (56.67%) and in 2 of the 35 cases (5.71%). The postponement of delivery between the two groups. There was highly significantly difference (P less than 0.01). There was a significant correlation of cervical dilation at the onset of treatment to success of controlling preterm labor. In the magnesium sulfate group, the mean magnesium level to achieve tocolysis was 2.8 +/- 0.35 mmol/L (mean +/- s). The side effects to the mothers, fetus, and the neonates were mild and not prominent.(ABSTRACT TRUNCATED AT 250 WORDS)
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