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Liu YY, Han TY, Giuliano AE, Ichikawa S, Hirabayashi Y, Cabot MC. Glycosylation of ceramide potentiates cellular resistance to tumor necrosis factor-alpha-induced apoptosis. Exp Cell Res 1999; 252:464-70. [PMID: 10527636 DOI: 10.1006/excr.1999.4649] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ceramide, as a second messenger, initiates one of the major signal transduction pathways in tumor necrosis factor-alpha (TNF-alpha)-induced apoptosis. Glucosylceramide synthase (GCS) catalyzes glycosylation of ceramide and produces glucosylceramide. By introduction of the GCS gene, cytotoxic resistance to TNF-alpha has been conferred in human breast cancer cells. MCF-7/GCS-transfected cells expressed 4.1-fold higher levels of GCS activity and exhibited a 15-fold (P < 0.0005) greater EC(50) for TNF-alpha, compared with the parental MCF-7 cell line. DNA fragmentation and DNA synthesis studies showed that TNF-alpha had little influence on the induction of apoptosis or on growth arrest in MCF-7/GCS cells, compared to MCF-7 cells. These studies reveal that TNF-alpha resistance in MCF-7/GCS cells is closely related to ceramide hyperglycosylation, a hallmark of this transfected cell line, and resistance was not aligned with changes in TNF receptor 1 expression. This work demonstrates that GCS, which catalyzes ceramide glycosylation, potentiates cytotoxic resistance to TNF-alpha.
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Liu YY, Lee YC, Chou TY, Perng RP. Pulmonary alveolar-septal amyloidosis presenting as heart failure with unilateral pleural effusion: a case report. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1999; 62:838-43. [PMID: 10575815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
We report a case of pulmonary alveolar-septal amyloidosis associated with chylothorax and paraproteinemia initially presenting as congestive heart failure with unilateral pleural effusion. A 72-year-old man was initially diagnosed with congestive heart failure based on the correlation of clinical manifestation and chest radiography. Concentric left ventricular hypertrophy with mild hypokinesis of the left ventricle was found on cardiac echography. Thoracocentesis was performed for right-sided pleural effusion, which persisted despite medical treatment; chylous exudate was aspirated. Because the etiology of the exudative pleural effusion was undetermined, the patient underwent a thoracotomy that showed pulmonary alveolar-septal amyloidosis. Immunoglobulin M paraproteinemia was identified by serum immunoelectrophoresis. We conclude that it is imperative to search for the cause of an undetermined exudative pleural effusion, with particular attention to chylothorax and amyloidosis as the differential diagnoses.
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Lucci A, Giuliano AE, Han TY, Dinur T, Liu YY, Senchenkov A, Cabot MC. Ceramide toxicity and metabolism differ in wild-type and multidrug-resistant cancer cells. Int J Oncol 1999; 15:535-40. [PMID: 10427136 DOI: 10.3892/ijo.15.3.535] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Previously we demonstrated that multidrug-resistant (MDR) cancer cells have elevated levels of a glycosylated form of ceramide, glucosylceramide. Here we compared ceramide metabolism and ceramide toxicity in MCF-7 and in adriamycin-resistant (MCF-7-AdrR) human breast cancer cells. MCF-7-AdrR cells were resistant to C6-ceramide (1-10 microM); however, in MCF-7 cells treated with C6-ceramide, viability dropped sharply. Ceramide, when supplemented, was not metabolized by MCF-7 cells. In contrast, ceramide was efficiently converted to glucosylceramide by MCF-7-AdrR cells. Analysis of extracellular [3H]ceramide in radiolabeled cells showed that MCF-7-AdrR cells do not have an enhanced capacity to efflux ceramide compared with MCF-7 cells. Triphenylethylene anti-estrogens, known modulators of drug resistance, were effective inhibitors of ceramide conversion to glucosylceramide, suggesting that blocking ceramide metabolism plays a role in chemosensitization. The anti-progestine, RU486, also blocked glucosylceramide synthesis in cells; however, LY117018, a raloxifene analog, was without influence. We propose that an enhanced capacity to glycosylate ceramide as evidenced in MCF-7-AdrR cells, is a molecular determinant of drug resistance, particularly as regards resistance to ceramide-enhancing agents such as anthracyclines, ionizing radiation, and tumor necrosis factor-alpha.
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Lucci A, Han TY, Liu YY, Giuliano AE, Cabot MC. Modification of ceramide metabolism increases cancer cell sensitivity to cytotoxics. Int J Oncol 1999; 15:541-6. [PMID: 10427137 DOI: 10.3892/ijo.15.3.541] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the preceding report we demonstrated that MCF-7-AdrR cells (adriamycin resistant) were insensitive to ceramide, whereas MCF-7 wild-type cells were sensitive. It was also shown that the drug resistant cells had an increased capacity to convert ceramide to glucosylceramide. Here we demonstrate that blocking the conversion of ceramide to glucosylceramide increases MCF-7-AdrR cell sensitivity to ceramide as well as to antitumor agents. Treatment of MCF-7 cells with adriamycin elicited a 5-fold increase in ceramide, and caused oligonucleosomal fragmentation, characteristic to apoptosis. Under similar treatment conditions, ceramide was not generated in MCF-7-AdrR cells. In MCF-7-AdrR cells neither C6-ceramide nor tamoxifen was cytotoxic; however, the addition of tamoxifen to the C6-ceramide treatment regimen reduced cell viability to 42% and elicited apoptosis. Treatment of MCF-7-AdrR cells with Adriamycin promoted an increase in ceramide only if tamoxifen was present, in which case ceramide increased 7-fold, and cell viability decreased to 50%. The employment of another agent, RU486 (Mifepristone), which blocks ceramide glycosylation, increased MCF-7-AdrR cell sensitivity to adriamycin in a dose-dependent manner. Our data show that agents that block ceramide glycosylation potentiate cellular sensitivity to ceramide and to chemotherapeutic drugs, and suggest that the ceramide metabolic pathway is an important target for anticancer drug development.
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Lucci A, Han TY, Liu YY, Giuliano AE, Cabot MC. Multidrug resistance modulators and doxorubicin synergize to elevate ceramide levels and elicit apoptosis in drug-resistant cancer cells. Cancer 1999; 86:300-11. [PMID: 10421266 DOI: 10.1002/(sici)1097-0142(19990715)86:2<300::aid-cncr14>3.0.co;2-h] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND To provide insight for the development of more effective clinical agents, the authors attempted to elucidate the mechanisms of action of multidrug resistance (MDR) modulators. Previously, the authors found that MDR modulators blocked the conversion of ceramide to glucosylceramide in MDR cells, thereby enhancing cytotoxicity. Because ceramide is a critical component of the apoptosis signaling cascade, the current study examined the impact of therapy using agents that elicit ceramide formation combined with agents that block ceramide glycosylation. METHODS Doxorubicin-resistant human breast carcinoma cells (MCF-7-AdrR) were treated with either doxorubicin, tamoxifen, cyclosporine A, or the cyclosporine A analog SDZ PSC 833 (PSC 833) or with combinations thereof, and ceramide and glucosylceramide metabolisms were measured by cell radiolabeling. Cell viability was quantitated spectrophotometrically and apoptosis was evaluated analyzing DNA integrity by gel electrophoresis. RESULTS Whereas cyclosporine A blocked the generation of glucosylceramide in MCF-7-AdrR cells, a chemical cousin, PSC 833, elicited a 3-fold increase in glucosylceramide and a 5-fold increase in ceramide levels at 24 hours. The PSC 833 response was time-dependent(as early as 30 minutes) and dose-dependent (as low as 0.1 microM). The appearance of ceramide foreran the generation of glucosylceramide. Sphingomyelin levels were not decreased in response to PSC 833; however, Fumonisin B1, a ceramide synthase inhibitor, blocked PSC 833-induced ceramide generation. Adding tamoxifen, which blocks ceramide glycosylation, to the PSC 833 regimen boosted ceramide levels 11-fold over controls and caused DNA fragmentation. A 3-component regimen comprised of tamoxifen, doxorubicin, and PSC 833 increased ceramide levels 26-fold and brought cell viability to zero. CONCLUSIONS These results demonstrate that MDR modulators can be used separately, in combination, or in conjunction with chemotherapy at clinically relevant concentrations to manipulate cellular ceramide levels and restore sensitivity in the drug resistant setting. As such, this represents a new direction in the treatment of cancer.
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Abstract
BACKGROUND/AIMS Partial hepatectomy results in activation of genes in the residual liver tissue which serve to restore glucose homeostasis and regenerate liver mass. Expression of insulin-like growth factor binding protein-1 (IGFBP-1) is up-regulated following partial hepatectomy and IGFBP-1 can modulate both the metabolic and mitogenic effects of insulin-like growth factor-1 (IGF-I). The aim of the study was to compare the effects of partial hepatectomy on blood glucose levels and hepatic regeneration in wild-type and transgenic mice which constitutively overexpress IGFBP-1. METHODS Hepatic IGFBP-1 mRNA, blood glucose concentrations, liver mass and hepatic DNA synthesis were compared in sham-operated and partially hepatectomized transgenic and wild-type mice. RESULTS Hepatic IGFBP-1 mRNA was higher in sham-operated transgenic than wild-type mice, but in both groups of mice, partial hepatectomy was associated with a significant rise in IGFBP-1 mRNA. The absolute decline in blood glucose levels following partial hepatectomy was greater in transgenic mice. Basal DNA synthesis and the response to IGF-I in isolated hepatocytes from both groups of mice were similar, and DNA synthesis in the regenerating liver in vivo was not significantly different in transgenic as compared to wild-type mice: 449.3 +/- 63.9 vs. 321.6 +/- 52.3 cpm/microgram DNA. Hepatic regeneration as measured by liver weight after hepatectomy was not different between transgenic and wild-type mice. CONCLUSIONS Constitutive overexpression of IGFBP-1 does not enhance hepatic regeneration and does not prevent the decline in blood glucose following partial hepatectomy.
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Cabot MC, Giuliano AE, Han TY, Liu YY. SDZ PSC 833, the cyclosporine A analogue and multidrug resistance modulator, activates ceramide synthesis and increases vinblastine sensitivity in drug-sensitive and drug-resistant cancer cells. Cancer Res 1999; 59:880-5. [PMID: 10029079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Resistance to chemotherapy is the major cause of cancer treatment failure. Insight into the mechanism of action of agents that modulate multidrug resistance (MDR) is instrumental for the design of more effective treatment modalities. Here we show, using KB-V-1 MDR human epidermoid carcinoma cells and [3H]palmitic acid as metabolic tracer, that the MDR modulator SDZ PSC 833 (PSC 833) activates ceramide synthesis. In a short time course experiment, ceramide was generated as early as 15 min (40% increase) after the addition of PSC 833 (5.0 microM), and by 3 h, [3H]ceramide was >3-fold that of control cells. A 24-h dose-response experiment showed that at 1.0 and 10 microM PSC 833, ceramide levels were 2.5- and 13.6-fold higher, respectively, than in untreated cells. Concomitant with the increase in cellular ceramide was a progressive decrease in cell survival, suggesting that ceramide elicited a cytotoxic response. Analysis of DNA in cells treated with PSC 833 showed oligonucleosomal DNA fragmentation, characteristic of apoptosis. The inclusion of fumonisin B1, a ceramide synthase inhibitor, blocked PSC 833-induced ceramide generation. Assessment of ceramide mass by TLC lipid charring confirmed that PSC 833 markedly enhanced ceramide synthesis, not only in KB-V-1 cells but also in wild-type KB-3-1 cells. The capacity of PSC 833 to reverse drug resistance was demonstrated with vinblastine. Whereas each agent at a concentration of 1.0 microM reduced cell survival by approximately 20%, when PSC 833 and vinblastine were coadministered, cell viability fell to zero. In parallel experiments measuring ceramide metabolism, it was shown that the PSC 833/vinblastine combination synergistically increased cellular ceramide levels. Vinblastine toxicity, also intensified by PSC 833 in wild-type KB-3-1 cells, was as well accompanied by enhanced ceramide formation. These data demonstrate that PSC 833 has mechanisms of action in addition to P-glycoprotein chemotherapy efflux pumping.
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Liu YY, Han TY, Giuliano AE, Cabot MC. Expression of glucosylceramide synthase, converting ceramide to glucosylceramide, confers adriamycin resistance in human breast cancer cells. J Biol Chem 1999; 274:1140-6. [PMID: 9873062 DOI: 10.1074/jbc.274.2.1140] [Citation(s) in RCA: 210] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Multidrug-resistant cancer cells display elevated levels of glucosylceramide (Lavie, Y., Cao, H. T., Volner, A., Lucci, A., Han, T. Y., Geffen, V., Giuliano, A. E., and Cabot, M. C. (1997) J. Biol. Chem. 272, 1682-1687). In this study, we have introduced glucosylceramide synthase (GCS) into wild type MCF-7 breast cancer cells using a retroviral tetracycline-on expression system, and we developed a cell line, MCF-7/GCS. MCF-7/GCS cells expressed an 11-fold higher level of GCS activity compared with the parental cell line. Interestingly, the transfected cells demonstrated strong resistance to adriamycin and to ceramide, whereas both agents were highly cytotoxic to MCF-7 cells. The EC50 values of adriamycin and ceramide were 11-fold (p < 0.0005) and 5-fold (p < 0.005) higher, respectively, in MCF-7/GCS cells compared with MCF-7 cells. Ceramide resistance displayed by MCF-7/GCS cells closely paralleled the activity of expressed GCS with a correlation coefficient of 0.99. In turn, cellular resistance and GCS activity were dependent upon the concentration of the expression mediator doxycycline. Adriamycin resistance in MCF-7/GCS cells was related to the hyperglycosylation of ceramide and was not related to shifts in the levels of either P-glycoprotein or Bcl-2. This work demonstrates that overexpression of GCS, which catalyzes ceramide glycosylation, induces resistance to adriamycin and ceramide in MCF-7 breast cancer cells.
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Lavie Y, Zhang ZC, Cao HT, Han TY, Jones RC, Liu YY, Jarman M, Hardcastle IR, Giuliano AE, Cabot MC. Tamoxifen induces selective membrane association of protein kinase C epsilon in MCF-7 human breast cancer cells. Int J Cancer 1998; 77:928-32. [PMID: 9714066 DOI: 10.1002/(sici)1097-0215(19980911)77:6<928::aid-ijc22>3.0.co;2-w] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Tamoxifen, a synthetic antiestrogen, is known for its antitumoral action in vivo; however, it is well accepted that many tamoxifen effects are elicited via estrogen receptor-independent routes. Previously, we reported that tamoxifen induces PKC translocation in fibroblasts. In the present study, we investigated the influence of tamoxifen, and several triphenylethylene derivatives, on protein kinase C (PKC) in MCF-7 human breast cancer cells. As measured by Western blot analysis, tamoxifen elicited isozyme-specific membrane association of PKC-epsilon, which was time-dependent (as early as 5 min post-treatment) and dose-dependent (5.0-20 microM). Tamoxifen did not influence translocation of alpha, beta, gamma, delta or zeta PKC isoforms. Structure-activity relationship studies demonstrated chemical requirements for PKC-epsilon translocation, with tamoxifen, 3-OH-tamoxifen and clomiphene being active. Compounds without the basic amino side chain, such as triphenylethylene, or minus a phenyl group, such as N,N-dimethyl-2-[(4-phenylmethyl)phenoxy]ethanamine, were not active. In vitro cell growth assays showed a correlation between agent-induced PKC-epsilon translocation and inhibition of cell growth. Exposure of cells to clomiphene resulted in apoptosis. Since PKC-epsilon has been associated with cell differentiation and cellular growth-related processes, the antiproliferative influence of tamoxifen on MCF-7 cells may be related to the interaction with PKC-epsilon.
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Abstract
BACKGROUND There is evidence suggesting cross-talk among gland cells of the anterior pituitary. We had reported a rare form of synaptoid contact between corticotrophs in the anterior pituitary of the dog. We then found similar synaptoid contacts with different characteristics in the rat, as described in the present article. METHODS Male Sprague-Dawley rats were used. The anterior pituitaries were prepared for ultrastructural study of substance P immunoreactivity of the anterior pituitary. Routine preembedding immunohistochemical staining was conducted, the sections were embedded in Epon 812 (Serva Feinbiochemica, Heidelberg, New York), and ultrathin sections were prepared. RESULTS In the anterior pituitary of the rat, synaptoid contacts were found between corticotrophs and lactotrophs. They appeared very close to typical synapses in the central nervous system, aside from evident weakness of presynaptic density. CONCLUSIONS The presence of synaptoid contacts suggests a form of cross-talk between the gland cells in the anterior pituitary of the rat.
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Liu YY, Ju G. Galanin-like immunoreactive nerve fibres in the anterior pituitary of the normal and adrenalectomized rat. Acta Histochem 1998; 100:149-56. [PMID: 9587626 DOI: 10.1016/s0065-1281(98)80023-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Our previous studies have shown the presence of substantial amounts of substance P and calcitonin gene-related peptide-like immunoreactive nerve fibres in the anterior pituitary of the monkey, dog and rat. Furthermore, synaptic relationships have been demonstrated between these nerve fibres and the gland cells in the dog and rat. The substance P and calcitonin gene-related nerve fibres increase in number following adrenalectomy and ovariectomy, respectively. The present study was aimed to investigate the galanin-containing nerve fibres in the anterior pituitary of normal and adrenalectomized rats. The results showed only a small amount of galanin-like immunoreactive nerve fibres in the normal anterior pituitary, which were present among the gland cells as well as along the blood vessels. Following adrenalectomy, the number of galanin-like immunoreactive nerve fibres increased and ramification appeared more frequently. The results substantiate our hypothesis of a dual neural-humoral regulation of the mammalian anterior pituitary gland.
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Liu YY, Collins ED, Norman AW, Peleg S. Differential interaction of 1alpha,25-dihydroxyvitamin D3 analogues and their 20-epi homologues with the vitamin D receptor. J Biol Chem 1997; 272:3336-45. [PMID: 9013574 DOI: 10.1074/jbc.272.6.3336] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
An important focus of structure-function studies of synthetic ligands for the vitamin D receptor (VDR) concerns the chiral center at carbon 20 of the steroid side chain; 20-epi analogues are 100-10, 000 times more potent transcriptionally than the natural hormone 1alpha,25-dihydroxyvitamin D3 (1alpha,25-(OH)2D3). We have compared the binding properties of three pairs of analogues either with a natural (N) or 20-epi (E) orientation. In intact cells, 45-60% of VDR.N-analogue complexes, but only 5-20% of VDR.E-analogue complexes, dissociated over a 3-h interval. The two groups of ligands induced distinct changes in VDR conformation as revealed by protease clipping assays. Mapping of ligand-VDR binding activity by deletions indicated that amino acids 420-427 were important for high affinity of VDR.N-analogue complexes, but not for VDR.E-analogue complexes. Site-directed mutagenesis revealed that residues 421 and 422 were essential for 1alpha,25-(OH)2D3-induced conformational changes, high affinity of 1alpha,25-(OH)2D3 for VDR, and transcriptional activity, but not for binding of its 20-epi analogue. In contrast, deletion of residues 396-427 abolished binding of 1alpha,25-(OH)2D3, but binding of its 20-epi analogue was still detectable. The results suggest that the ligand-binding domain of VDR has multiple and different contact sites for the two families of side chain-modified ligands, resulting in VDR.ligand complexes with different half-lives and transcriptional activities.
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Siu-Caldera ML, Clark JW, Santos-Moore A, Peleg S, Liu YY, Uskoković MR, Sharma S, Reddy GS. 1alpha,25-dihydroxy-24-oxo-16-ene vitamin D3, a metabolite of a synthetic vitamin D3 analog, 1alpha,25-dihydroxy-16-ene vitamin D3, is equipotent to its parent in modulating growth and differentiation of human leukemic cells. J Steroid Biochem Mol Biol 1996; 59:405-12. [PMID: 9010346 DOI: 10.1016/s0960-0760(96)00134-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
1alpha,25(OH)2-16-ene-D3, a synthetic analog of the steroid hormone, 1alpha,25(OH)2D3, has great potential to become a drug in the treatment of leukemia and other proliferative disorders, because of its minimal in vivo calcemic activity associated with a potent inhibitory effect on cell growth. However, at present, the mechanisms through which 1alpha,25(OH)2-16-ene-D3 expresses its biological activities are still not completely understood. Our previous in vitro study in a perfused rat kidney indicated for the first time that 1alpha,25(OH)2-16-ene-D3 and 1alpha,25(OH)2D3 are metabolized differently. 1alpha,25(OH)2-24-oxo-16-ene-D3, an intermediary metabolite of 1alpha,25(OH)2-16-ene-D3 formed through the C-24 oxidation pathway, accumulated significantly in the perfusate when compared to 1alpha,25(OH)2-24-oxo-D3, the corresponding intermediary metabolite of 1alpha,25(OH)2D3. In a subsequent in vivo study, we also reported that 1alpha,25(OH)2-24-oxo-16-ene-D3 exerted immunosuppressive activity equal to its parent, without causing significant hypercalcemia. In order to establish further the critical role of 1alpha,25(OH)2-24-oxo-16-ene-D3, in generating some of the key biological activities ascribed to its parent, we performed the present in vitro study using a human myeloid leukemic cell line (RWLeu-4) as a model. Comparative target tissue metabolism studies indicated that 1alpha,25(OH)2-16-ene-D3 and 1alpha,25(OH)2D3 are metabolized differently in RWLeu-4 cells, and the differences were similar to the ones we previously observed in the rat kidney. The significant finding was the accumulation of 1alpha,25(OH)2-24-oxo-16-ene-D3 in RWLeu-4 cells because of its resistance to further metabolism. Biological activity studies indicated that both 1alpha,25(OH)2-16-ene-D3 and its 24-oxo metabolite produced growth inhibition and promoted differentiation of RWLeu-4 cells to the same extent, and these activities were several fold higher than those exerted by 1alpha,25(OH)2D3. In addition, the genomic action of each vitamin D compound was assessed in a rat osteosarcoma cell line (ROS 17/2.8) by measuring its ability to transactivate a gene construct containing the vitamin D response element of the osteocalcin gene linked to the growth hormone reporter gene. In these studies, both 1alpha,25(OH)2-16-ene-D3 and its 24-oxo metabolite exerted similar but potent transactivation activity which was several fold greater than that exerted by 1alpha,25(OH)2D3 itself. In summary, our results indicate that the production and slow clearance of the bioactive intermediary metabolite, 1alpha,25(OH)2-24-oxo-16-ene-D3, in RWLeu-4 cells contributes significantly to the final expression of the enhanced biological activities ascribed to its parent analog, 1alpha,25(OH)2-16-ene-D3.
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Peleg S, Liu YY, Reddy S, Horst RL, White MC, Posner GH. A 20-epi side chain restores growth-regulatory and transcriptional activities of an A ring-modified hybrid analog of 1 alpha, 25-dihydroxyvitamin D3 without increasing its affinity to the vitamin D receptor. J Cell Biochem 1996; 63:149-61. [PMID: 8913867 DOI: 10.1002/(sici)1097-4644(19961101)63:2<149::aid-jcb3>3.0.co;2-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
1 alpha-hydroxymethyl-25-hydroxyvitamin D3 and 1 beta-hydroxymethyl -3 alpha,25-hydroxyvitamin D3, two analogs with modifications restricted to the A ring, bind poorly to vitamin D receptor (VDR). The effective doses required for 50% of maximal binding activity (ED50) are 7 x 10(-7) M for the former and 8 x 10(-8) M for the latter, and the ED50 for their growth-inhibitory activities is greater than 10(-6) M. Unexpectedly, a hybrid analog with 20-epi configuration at its side chain and a 1 beta-hydroxymethyl group but not a 1 alpha-hydroxymethyl group inhibits malignant cell growth with an ED50 of 7 x 10(-9) M. To determine if the restored biological activity of the hybrid analog is associated with better binding to VDR, we performed competitive binding assays in vitro with calf thymus VDR and in vivo with recombinant human VDR. We found that the 20 epi side chain reduced the affinity of the 1 beta- and the 1 alpha-hydroxymethyl hybrid analogs for VDR in vitro and in vivo fourfold to tenfold. To determine whether the 1 beta-hydroxymethyl analogs induced a VDR-mediated transcription, we tested the induction of reporter gene expression through the osteocalcin vitamin D response element (VDRE) in ROS 17/2.8 cells and the induction of binding activity of VDR to VDRE in COS-1 cells. We found that the ED50 for transcriptional activity of 1 beta-hydroxymethyl-3 alpha,25-hydroxyvitamin D3 was greater than 10(-6) M, but its 1 alpha diastereomer had barely detectable transcriptional activity. The 20-epi side chain preferentially increased the transcriptional activity of the 1 beta-hydroxymethyl hybrid analog to an ED50 of 10(-8) M, but the 1 alpha-hydroxymethyl hybrid analog remained inactive. To confirm that this transcriptional activity was dependent on the VDR, we repeated the assay in VDR-negative CV-1 cells and compared ligand-dependent expression of the VDRE/growth hormone reporter in the presence of either wild-type or transcriptionally inactive mutant VDR expression vectors. Transcription was induced by the 1 beta-hydroxymethyl compounds only in the presence of wild-type VDR. Thus, we conclude that it is possible, by adding a 20 epi side chain, to restore growth-inhibitory and VDR-mediated transcriptional activities without increasing binding to the VDR of A ring-modified analogs.
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Sun LZ, Liu YY. Studying Higgs pair production in the process gamma gamma -->H0H0 in the two-Higgs-doublet model. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1996; 54:3563-3569. [PMID: 10021028 DOI: 10.1103/physrevd.54.3563] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Valensise H, Liu YY, Federici M, Lauro D, Dell'anna D, Romanini C, Sesti G. Increased expression of low-affinity insulin receptor isoform and insulin/insulin-like growth factor-I hybrid receptors in term placenta from insulin-resistant women with gestational hypertension. Diabetologia 1996; 39:952-60. [PMID: 8858218 DOI: 10.1007/bf00403915] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Gestational hypertension is associated with insulin-resistance; insulin and insulin-like growth factor-1 (IGF-1), acting through their receptors, play a role in the growth of the feto-placental unit. Since both receptors are exposed to the maternal circulation, it has been suggested that maternal metabolic abnormalities might affect placental insulin (HIR) and IGF-1 (IGF-1R) receptors. To clarify this issue, we characterized HIR and IGF-1R in placenta at term from normal women, normoinsulinaemic women with gestational hypertension (NGH), and hyperinsulinaemic women with gestational hypertension (HGH). Insulin binding was decreased in HGH women (B/T 0.12 +/- 0.03) compared to control and NGH women (B/T 0.18 +/- 0.07, p < 0.036; and 0.22 +/- 0.5, p < 0.009 respectively). Receptor affinity was lower in HGH women (ED50 0.95 +/- 0.32 nmol/l) than control and NGH women (ED50 0.42 +/- 0.19 nmol/l, p < 0.01; and 0.40 +/- 0.1 nmol/l, p < 0.007, respectively), whereas low-affinity Ex11+ isoform was higher in HGH women (Ex11+ 50 +/- 7, %) than in control and NGH women (Ex11+ 34 +/- 9%, p < 0.001; and 39 +/- 4%, p < 0.01, respectively). Increased expression of Ex11+ isoform was correlated with ED50 (r = 0.71; p < 0.002) and insulinaemia (r = 0.70, p < 0.002). IGF-I binding was increased in HGH women (B/T 0.17 +/- 0.03) compared to control and NGH women (B/T 0.09 +/- 0.05, p < 0.002; and 0.11 +/- 0.03, p < 0.002, respectively). IGF-IR affinity was similar in the three groups. The percentage of insulin/IGF-I hybrid receptors was increased in HGH women (85 +/- 3%) compared to control and NGH women (68 +/- 7%, p < 0.001; and 63 +/- 9%, p < 0.001, respectively), and was positively correlated with insulinaemia (r = 0.62, p < 0.018), ED50 of insulin binding (r = 0.62, p < 0.05), and maximal IGF-I binding (r = 0.69, p < 0.004); whereas it was inversely correlated with maximal insulin binding (r = -0.69, p < 0.004). Results provide the first evidence for altered expression of insulin/IGF-I hybrids found in insulin-resistance states.
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Sabbioni G, Wei J, Liu YY. Determination of hemoglobin adducts in workers exposed to 2,4, 6-trinitrotoluene. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1996; 682:243-8. [PMID: 8844416 DOI: 10.1016/0378-4347(96)00083-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
2,4,6-Trinitrotoluene (TNT) is an important occupational and environmental pollutant. TNT can be taken up through the skin and by inhalation. It is therefore essential to have fast and reliable methods to monitor human exposure. In rat experiments, it has been shown that TNT binds covalently to blood proteins and to tissue proteins. Hemoglobin (Hb) adducts of TNT are markers for the internal dose and possibly for the toxic effects of TNT, e.g. cataracts. In the present paper we introduce a new efficient method to quantify Hb adducts of TNT. Precipitated Hb was hydrolyzed with base in the presence of the surrogate internal standard 3,5-dinitroaniline (35DNA). The released 2-amino-4,6-dinitrotoluene (2ADNT) and 4-amino-2,6-dinitrotoluene (4ADNT) were quantified against 35DNA by gas chromatography-mass spectrometry with negative-ion chemical ionization. Hb of 50 workers and controls from a Chinese munition factory were investigated. The Hb adduct levels ranged from 3.7 to 522 ng for 4ADNT and from 0 to 14.7 ng for 2ADNT per gram of Hb. However, in control samples from Germany no Hb adducts of 4ADNT or 2ADNT could be found.
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218
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Fischman AJ, Livni E, Babich JW, Alpert NM, Bonab A, Chodosh S, McGovern F, Kamitsuka P, Liu YY, Cleeland R, Prosser BL, Correia JA, Rubin RH. Pharmacokinetics of [18F]fleroxacin in patients with acute exacerbations of chronic bronchitis and complicated urinary tract infection studied by positron emission tomography. Antimicrob Agents Chemother 1996; 40:659-64. [PMID: 8851589 PMCID: PMC163176 DOI: 10.1128/aac.40.3.659] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The pharmacokinetics of fleroxacin, a new broad-spectrum fluoroquinolone, were measured by positron emission tomography (PET) with [18F]fleroxacin in five patients with acute bacterial exacerbations of chronic bronchitis and in five patients with symptomatic, complicated urinary tract infection. Two studies were performed with each patient, one within 24 h of the initiation and one within 24 h of the completion of a 7-day course of fleroxacin, 400 mg/day. For each study, the patient received an infusion of that day's therapeutic dose of fleroxacin (400 mg) supplemented with approximately 740 MBq of [18F]fleroxacin, and serial PET images and blood samples were collected for 6 to 8 h starting at the initiation of the infusion. Between studies, the drug was administered orally. In all infected tissues, there was rapid accumulation of radiolabeled drug, with stable levels achieved within 1 h after completion of the infusion. In kidneys, accumulation was greater in the presence of active infection (P < 0.01), while in lungs, accumulation was lower (P < 0.02). Infection of the lung or urinary tract had no effect on drug delivery to uninvolved tissues. Also, there was no difference between the results obtained at the beginning and the end of therapy. Overall, peak concentrations of drug many times the MIC at which 90% of the infecting organisms are inhibited (MIC90) were achieved in the kidneys (> 30 micrograms/g), prostate glands (> 11 micrograms/g), and lungs (> 14 micrograms/g). Plateau concentrations (2 to 8 h; given as mean micrograms per gram +/- standard error of the mean) of drug in kidneys (15.11 +/- 0.55), prostate glands (5.08 +/- 0.19), and lungs (5.75 +/- 0.22) were also well above the MIC90 for most relevant pathogens. All patients had a good therapeutic response to fleroxacin.
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219
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Sun LZ, Liu YY. Electroweak radiative corrections to tt-bar-->H0H0 in the two-Higgs-doublet model. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1996; 53:2411-2420. [PMID: 10020238 DOI: 10.1103/physrevd.53.2411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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220
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Sesti G, D'Alfonso R, Vargas Punti MD, Tullio AN, Liu YY, Federici M, Borboni P, Marini MA, Lauro R, Fusco A. Delayed intracellular dissociation of the insulin-receptor complex impairs receptor recycling and insulin processing in cultured Epstein-Barr virus-transformed lymphocytes from insulin-resistant subjects. Diabetologia 1996; 39:289-95. [PMID: 8721774 DOI: 10.1007/bf00418344] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Insulin-receptor internalization and processing are defective in insulin-resistant subjects. To assess the reversibility of these defects, we cultured Epstein-Barr virus-transformed-lymphoblasts from six normal, six obese, and six non-insulin-dependent diabetic (NIDDM) subjects in media containing low (5 mmol/l) or high (25 mmol/l) glucose concentrations, and studied the insulin-receptor internalization and processing in vitro. In cells from normal, obese, and NIDDM subjects cultured in low glucose concentrations, exposure to 100 nmol/l insulin for 30 min at 37 degrees C reduced cell-surface 125I-insulin binding to a similar extent (82 +/- 2, 77 +/- 5, and 82 +/- 5% of initial values, respectively). The same results were obtained with cells cultured in high glucose concentrations. In cells cultured under both glucose conditions, and exposed to 100 nmol/l insulin for 30 min at 37 degrees C, a complete recovery of the initial 125I-insulin binding was observed in normal but not in obese and NIDDM subjects. Release of intracellular insulin and its degradation in vitro was determined by incubating cells with 600 pmol/l of 125I-insulin for 60 min at 37 degrees C, acid washing cells, and re-incubating in insulin-free buffer at 37 degrees C. The radioactivity released by cells was characterized by trichloroacetic acid precipitability, Sephadex G-50 column chromatography, and re-binding to fresh cells. Rates of release of internalized radioactivity were reduced in obese and NIDDM subjects (t1/2 = 61 +/- 9 min, p < 0.02; 58 +/- 10 min, p < 0.05; and 38 +/- 4 min in obese, NIDDM, and normal subjects, respectively). The percentage of intact insulin released from cells was significantly higher in obese and NIDDM subjects than in the normal subjects. The t1/2 of intracellular dissociation of insulin-receptor complexes measured by a polyethylene glycol assay was lower in normal (6 +/- 1 min) than in obese (12 +/- 2 min, p < 0.03) and NIDDM subjects (14 +/- 3 min, p < 0.02). The results suggest that in insulin-resistant subjects a primary defect in intracellular dissociation of insulin is responsible for alterations of receptor recycling and insulin processing.
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221
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Tan S, Liu YY, Nielsen VG, Skinner K, Kirk KA, Baldwin ST, Parks DA. Maternal infusion of antioxidants (Trolox and ascorbic acid) protects the fetal heart in rabbit fetal hypoxia. Pediatr Res 1996; 39:499-503. [PMID: 8929872 DOI: 10.1203/00006450-199603000-00019] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The antioxidants, Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid, a water soluble analog of vitamin E) and ascorbic acid (AA), protect the heart from ischemia-reperfusion injury. We hypothesized that maternal infusion of Trolox and AA, would reduce the fetal bradycardia and myocardial damage observed in fetal hypoxia and increase the total antioxidant activity in fetal plasma. Either i.v. saline (control group) or Trolox + AA (drug group) was randomly administered to 29-d-old pregnant rabbits. Fetal hypoxia was induced by uterine ischemia. Fetal heart rate, plasma CK-MB activity, and plasma total radical antioxidant potential (TRAP) were measured in different sets of animals. Fetal heart rate in the drug group was higher than in the control group for the first 35 min (p < 0.05 at every 5-min interval). Fetal bradycardia (<60 beats/min) occurred after 39 min (median) in the drug group, and 29 min in the control group (p < 0.05). After 50 min of hypoxia, plasma CK-MB was lower in the drug group, 1204 +/- 132 U/L (mean +/- SEM), than in the control group, 2633 +/- 233 U/L (p < 0.05). TRAP was higher in the drug group, 3.01 +/- 0.15 mM (Trolox equivalent concentration), than in the control group, 1.48 +/- 0.27 mM (p < 0.05). Higher TRAP levels (> or = 2.0 mM) were associated with lower CK-MB levels (<2500 U/L) (p < 0.05). Administration of Trolox and AA to the mother has a beneficial effect on fetal myocardial damage after fetal hypoxia, and a small beneficial effect on fetal bradycardia during hypoxia. The beneficial effect may be due to the augmentation of fetal plasma antioxidants from maternal antioxidant pretreatment.
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222
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Rao CN, Ladin DA, Liu YY, Chilukuri K, Hou ZZ, Woodley DT. Alpha 1-antitrypsin is degraded and non-functional in chronic wounds but intact and functional in acute wounds: the inhibitor protects fibronectin from degradation by chronic wound fluid enzymes. J Invest Dermatol 1995; 105:572-8. [PMID: 7561161 DOI: 10.1111/1523-1747.ep12323503] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Fluid obtained from chronic and acute wounds were examined for the presence of fibronectin, alpha 1-antitrypsin, and proteinases capable of degrading both proteins. Immunoblot analysis of fluids from ten chronic wounds revealed that fibronectin and alpha 1-antitrypsin were degraded in nine of ten samples. In contrast, both fibronectin and alpha 1-antitrypsin were intact in acute wound fluids. The degradation of the inhibitor and fibronectin occurred in the same wound fluids, and these two events correlated perfectly. Chronic or acute wound fluid proteins were coupled to benzamidine Sepharose 6B beads and incubated with fibronectin or alpha 1-antitrypsin. Chronic wound fluid proteins degraded fibronectin in the presence of ethylenediaminetetraacetate, leupeptin, cystatin, and pepstatin but not in the presence of phenylmethylsulfonyl fluoride. Acute wound fluids and normal human serum did not contain enzymes capable of degrading fibronectin. These data suggest that serine proteinases are responsible for fibronectin degradation in chronic wound fluids. Chronic wound fluids that contained degraded alpha 1-antitrypsin also contain proteinases capable of degrading alpha 1-antitrypsin from human serum. Acute wound fluids and normal human serum did not contain enzymes capable of degrading alpha 1-antitrypsin. The inhibitor from acute wound fluids bound to one of its targets, trypsin. In contrast, the fragment(s) of alpha 1-antitrypsin from chronic wound fluids did not bind trypsin. Chronic wounds associated with degraded fibronectin and the inhibitor contained ten- to forty-fold more elastase activity than acute wounds. The degradation of fibronectin by chronic wound fluid enzymes was inhibited by alpha 1-antitrypsin in a dose-dependent manner. Collectively, these results demonstrate that there are enzymes in chronic wounds that perturb the function of alpha 1-antitrypsin and allow fibronectin degradation by uninhibited serine proteinases.
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223
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Liu BC, You BR, Liu YY, Wang GF, Miao Q, Li YR. Ceruloplasmin or fibronectin synergism with quartz dust on stimulating collagen gene transcription in human 2BS fibroblast. BIOMEDICAL AND ENVIRONMENTAL SCIENCES : BES 1995; 8:246-253. [PMID: 8561925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Human alpha 1(I), alpha 2(I) and alpha 1(III) cDNA probes and RNA dot hybridization were employed to quantitate collagen mRNA changes after adding silica dust into the media of human 2BS fibroblasts. At all dosages used (100, 200, 500 and 1000 micrograms), the alpha 1(I), alpha 2(I) and alpha 1(III) mRNA levels increased one day after dusting. At the same dosage of silica (100 micrograms), alpha 1(III) mRNA increased earlier than type I collagen mRNA did. The type I and type III collagen mRNA contents in the experimental groups were higher than those in control on days 3, 5, 7 and 9. The effect of ceruloplasmin (Cp) and fibronectin (Fn) on collagen mRNA synthesis was also studied, after adding silica dust, Cp or Fn into the media of human 2BS fibroblast. The results showed that Cp and Fn have stimulating effect on collagen mRNA production. When both Cp and silica dust were added into cell culture media, the collagen mRNA level was increased more than those of adding either Cp or silica dust alone. Similar situations were found for Fn. Cp (or Fn) synergism with silica dust on stimulating transcription of human collagen gene was suggested.
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224
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Iwasaki T, Olivry T, Lapiere JC, Chan LS, Peavey C, Liu YY, Jones JC, Ihrke PJ, Woodley DT. Canine bullous pemphigoid (BP): identification of the 180-kd canine BP antigen by circulating autoantibodies. Vet Pathol 1995; 32:387-93. [PMID: 7483213 DOI: 10.1177/030098589503200407] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Human bullous pemphigoid (BP) is an immune-mediated blistering disease characterized by autoantibodies against BP antigens (230/180 kd), which are constitutive glycoproteins of hemidesmosomes found in basal keratinocytes. Blistering diseases similar to human BP have been reported in dogs. IgG deposits at the basement membrane zone (BMZ) are a common feature of canine BP. Although circulating anti-BMZ IgG autoantibodies have been demonstrated in some cases of canine BP, the specific skin protein targeted by these autoantibodies has not been identified. In this study, we characterized the antigenic target of the autoantibodies in the serum from a 3-year-old castrated male Pit Bull Terrier with BP. Direct immunofluorescence of the patient's skin demonstrated IgG deposits at the dermal-epidermal junction. Indirect immunofluorescence demonstrated autoantibodies in the patient's serum that stained the epidermal roof of salt-split canine skin and left the dermal floor unstained. These serum autoantibodies did not stain normal intact dog skin but labeled intact bovine tongue. Direct immunoelectron microscopy of the dog's skin revealed IgG deposits within the hemidesmosomes of the basal keratinocytes. Western immunoblotting experiments showed that canine keratinocytes express both the 230-kd and 180-kd bullous pemphigoid antigens, and the autoantibodies from the patient's serum recognized the 180-kd bullous pemphigoid antigen in proteins extracted from canine and human keratinocytes. Canine BP has many parallel features with human BP including similar immune deposition of IgG within hemidesmosomes and a hemidesmosome-associated 180-kd glycoprotein target for circulating autoantibodies.
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225
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Lian QL, Hang RC, Yan HF, Chen T, Ni GT, Lu HQ, Liu YY, Liu XQ. Effects of hyperbaric oxygen on S-180 sarcoma in mice. Undersea Hyperb Med 1995; 22:153-160. [PMID: 7633277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The contents of oxygen free radicals (OFRs) and malondialdehyde (MDA) in S-180 sarcoma tissues were measured in four groups of mice: an untreated normoxic group, a normoxic hyperbaric group, a hyperbaric oxygen group, and an HBO group treated with superoxide dismutase (SOD). Measurements were done by electron resonance and spectrophotometry, and observations were made on the volume, weight, necrosis incidence rate of sarcoma tissues, and mortality in all groups. The OFR and MDA content in sarcoma tissues in the HBO group was significantly higher than those of the control groups (P < 0.001); necrosis incidence of sarcoma tissues and the survival rate of mice were higher; the time required for necrosis was shorter, and the volume and weight of sarcoma tissues were smaller and lighter than those of the control groups (P < 0.01). The results suggest that SOD cannot completely eliminate OFRs produced by hyperbaric exposure, although the role of HBO in producing more OFRs can be counterbalanced by SOD to a certain degree. Apparently HBO can check the growth rate of sarcoma and accelerate the necrosis of S-180 sarcoma cells.
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226
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Liu YY, Yao M, Fang JL, Wang YW. Monitoring human risk and exposure to trinitrotoluene (TNT) using haemoglobin adducts as biomarkers. Toxicol Lett 1995; 77:281-7. [PMID: 7618152 DOI: 10.1016/0378-4274(95)03308-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Two studies were carried out in a trinitrotoluene (TNT) plant using TNT haemoglobin (TNT-Hb) adduct as a biomarker to study dose-adduct and adduct-response relationships. In the first study, TNT-Hb adduct levels were determined in 117 TNT-exposed workers in different working sites with different exposure conditions. External exposure was calculated from the inhaled air concentration plus skin contamination. TNT-Hb adduct levels in blood were significantly correlated with their external exposure to TNT. Two methods, HPLC-UV and CI-ELISA, were developed for measuring TNT-Hb adduct: good correlations (r = 0.77 and 0.86) were found between these 2 methods. In the second study, TNT cataract was used as an indicator of health effects. The prevalence of cataract and the degree of lenticular damage increased with the increase of blood TNT-Hb level.
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227
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Sesti G, D'Alfonso R, Vargas Punti MD, Frittitta L, Trischitta V, Liu YY, Borboni P, Longhi R, Montemurro A, Lauro R. Peptide-based radioimmunoassay for the two isoforms of the human insulin receptor. Diabetologia 1995; 38:445-53. [PMID: 7796985 DOI: 10.1007/bf00410282] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The insulin receptor exists in two isoforms differing by the absence (HIR-A) or presence (HIR-B) of 12 amino acids in the COOH-terminus of the alpha-subunit as a consequence of alternative splicing of exon 11. In this study, we developed a radioimmunoassay for the two isoforms employing antibodies raised against two peptides, one (Pep-12) corresponding to residues encoded by exon 11, and the other (Pep-13) corresponding to a COOH-terminal domain of the alpha-subunit which is common to both HIR-A and HIR-B isoforms. These peptides were iodinated and used as both ligands and standards. The assay is specific, highly reproducible, and sensitive with a detection limit of 10 fmol of receptor. One mole of purified insulin receptor, measured by Scatchard analysis, is read as one mole of receptor in the radioimmunoassay with either Pep-12 or Pep-13 as standards. The radioimmunoassay is applicable to the measurement of total content and relative abundance of the two isoforms in extracts from various tissues. We applied the radioimmunoassay to measure the relative abundance of the two isoforms in fat and muscle from normal, obese non-diabetic and non-insulin-dependent diabetic (NIDDM) subjects. Results demonstrate that expression of the low-affinity HIR-B form is significantly increased in obese and NIDDM subjects compared with control subjects. In addition, the increased expression of the HIR-B isoform was significantly correlated with both body mass index (r = 0.52; p = 0.006) and fasting glucose levels (r = 0.59; p = 0.001).
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228
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Ruan WY, Liu YY, Bao CG, Zhang ZQ. Origin of magic angular momenta in few-electron quantum dots. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:7942-7945. [PMID: 9977395 DOI: 10.1103/physrevb.51.7942] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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229
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Rao CN, Peavey CL, Liu YY, Lapiere JC, Woodley DT. Partial characterization of matrix-associated serine protease inhibitors from human skin cells. J Invest Dermatol 1995; 104:379-83. [PMID: 7861006 DOI: 10.1111/1523-1747.ep12665851] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Serine protease inhibitors have important regulatory roles in angiogenesis, intravascular fibrinolysis, wound healing, and cell migration. In this study, the extracellular matrix secreted by cultured human keratinocytes, foreskin fibroblasts, and SV-40-transformed human skin fibroblasts was analyzed for serine protease inhibitors by substrate reverse zymography. We found that the extracellular matrix deposited by these cells contained three inhibitors (M(r) 33,000, 31,000, and 27,000). These inhibitors protected the degradation of gelatin by trypsin and elastase, and of casein by plasmin. In contrast, the gelatinolytic activities of thermolysin and papain were not inhibited. Compared to untreated cells, cells treated with phorbol 12-myristate 13-acetate showed a two- to 10-fold increase in the expression of these inhibitors. Cycloheximide and actinomycin D decreased the cellular expression of these inhibitors, suggesting the involvement of de novo protein and mRNA synthesis. Antitrypsin activity of these inhibitors was resistant to heat and sodium dodecylsulfate, but was lost after reduction of disulfide bonds. The inhibitors bound specifically to trypsin and could be eluted from a trypsin column in active form. Collectively, these data suggest that the extracellular matrix deposited by keratinocytes and dermal fibroblasts contains active serine protease inhibitors.
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230
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Rao CN, Liu YY, Peavey CL, Woodley DT. Novel extracellular matrix-associated serine proteinase inhibitors from human skin fibroblasts. Arch Biochem Biophys 1995; 317:311-4. [PMID: 7872799 DOI: 10.1006/abbi.1995.1168] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Serine proteinase inhibitors play a major role in the turnover of connective tissues. In this study, we isolated and determined partial amino-terminal amino acid sequence of trypsin/elastase/plasmin inhibitors (M(r) 33,000 and 31,000) from the extracellular matrix of SV40-transformed human skin fibroblasts. The antitrypsin activity of the inhibitors was monitored by substrate reverse zymography. Polyclonal antisera to alpha 1-antitrypsin, alpha 1-antichymotrypsin, alpha 2-antiplasmin, inter-alpha-trypsin inhibitor, plasminogen activator inhibitors-1 and -2, and a monoclonal antibody to protease nexin-1 did not label the 33-, 31-, and 27-kDa inhibitors. A computer search for amino acid sequence homology indicated that the 31-kDa inhibitor is novel. In contrast, the sequence of the 33-kDa inhibitor shared 70 to 90% homology with the amino-terminal sequence of a recently characterized 32-kDa trypsin/tissue factor inhibitor called tissue factor pathway inhibitor-2. The 33- and 31-kDa inhibitors bind to heparin-Sepharose and were recovered from the affinity beads as well as from the t12 FB extracellular matrix with 1 M NaCl. Based on these results, we propose that the extracellular matrix of human mesenchymal cells sequester a family of novel serine proteinase inhibitors.
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231
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Liu YY, Karim A, Kaderbhai MA. A chloroplast envelope-transfer transit peptide is export competent in Escherichia coli. Biochem Soc Trans 1995; 23:72S. [PMID: 7758790 DOI: 10.1042/bst023072s] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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232
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Suzuki H, Miura S, Liu YY, Tsuchiya M, Ishii H. Substance P induces degranulation of mast cells and leukocyte adhesion to venular endothelium. Peptides 1995; 16:1447-52. [PMID: 8745057 DOI: 10.1016/0196-9781(95)02050-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Substance P (SP), one of the established neurotransmitters, evokes an immunoinflammatory response involving leukocyte adhesion to venular endothelium and the degranulation of mast cells. The pathogenetic relationship between these responses, however, remains unresolved. In this study, we propose to examine the changes associated with the activation of mast cells, as well as leukocyte adhesion to venular endothelium by in vivo observation of the rat mesentery. The use of an in vitro assay for intracellular Ca2+ mobilization and the degranulation of mast cells demonstrated the significant upper shift of concentration response to SP (10(-4)-10(-5) M). In vivo experiments on the mesenteric microcirculation also showed that SP induced a significant increase in the number of degranulated mast cells as well as in the number of leukocytes adherent to the venular wall. Tranilast, a mast cell stabilizer, as well as SP antagonist (CP-96,345) significantly attenuated the extent of mast cell degranulation and leukocyte adhesion elicited by SP. Although an immunoneutralization against CD18 by WT-3 significantly attenuated the leukocyte adhesion, it had no influence on the mast cell degranulation after SP superfusion. These separate in vivo observations show that SP induces leukocyte adhesion to the venular endothelium, possibly through the degranulation of mast cells.
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Davis GM, Chen CE, Kang ZB, Liu YY. Snail hosts of Paragonimus in Asia and the Americas. BIOMEDICAL AND ENVIRONMENTAL SCIENCES : BES 1994; 7:369-382. [PMID: 7535537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We have undertaken a comprehensive review of snail hosts of Paragonimus world-wide exclusive of Africa based on modern malacological data, where available, and with consideration of the phylogeny of the snail groups involved. This is the first comprehensive review since those made by Chen (1979) and Chen et al. (1983), and there have been considerable taxonomic changes over the past decade. A number of names and concepts found in the medical malacological and parasitological literature up to the present time require revision or correction. There are vast radiations of snails of the superfamilies Cerithiacea and Rissoacea involved in the transmission of Paragonimus in China. We list 54 species world-wide of which 35(65%) occur in China. Revisions and corrections pertaining to China include: (i) The family Hydrobiidae does not occur in China or S.E. Asia, and the Pomatiopsidae should be used. (ii) The genus Bythinella is entirely European (Hydrobiidae: Amnicolinae). The so-called Bythinella of China belongs to the genus Erhaia (Pomatiopsidae). (iii) The generic name Pseudobythinella described from China is preoccupied, a junior synonym of Pseudobythinella Melville 1956, a fossil from England. All Chinese Pseudobythinella are now classified as Erhaia. (iv) Akiyoshia has been used as a generic name for some snails in Hunan transmitting Paragonimus. Akiyoshia is from Japan and biological/ecological data indicate that the Chinese taxon is not Akiyoshia. (v) The genus Tricula in recent Chinese literature is comprised of four genera determined by detailed comparative anatomical data: Tricula, Neotricula, Gammatricula, and Jinhongia. Shells cannot be used to discriminate among them. (vi) Tricula cristella has been consistently misidentified in collections in China and literature. However, genuine T. cristella does transmit Paragonimus skrjabini. (vii) Tricula minutoides in the Chinese literature has been misidentified, and specimens are T. cristella. (viii) The genus Melania and the family Melaniidae are used in the Chinese literature. The so-called melaniidae snails belong to the families Thiaridae, Pleuroceridae, and Melanopsidae. Asian Semisulcospira is pleurocerid while Melanoides and Tarebia are thiarid (ix) Semisulcospira libertina is correctly identified for populations ranging throughout Japan to Taiwan. This species is most probably not distributed throughout all south China, and intense systematic research on Semisulcospira is needed. A modern classification is given for snails transmitting Paragonimus.
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Liu YY. [Experience in nursing 16 cases of alcoholism delirium tremens]. ZHONGHUA HU LI ZA ZHI = CHINESE JOURNAL OF NURSING 1994; 29:525-7. [PMID: 7614627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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235
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Zhang XR, Sun Y, Liu YY. [Response rate of small cell lung cancer treated with CE-CAP alternating chemotherapy]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 1994; 16:302-5. [PMID: 7805563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
From Sep. 1989 to Dec. 1992, 122 evaluable patients with small cell lung cancer (SCLC) treated with chemotherapy combined with radiotherapy in our hospital were analysed. There were 95 men and 27 women. The age ranged from 20 to 70 years. All were proven by pathology or cytology. They all did not receive previous treatment and had a measurable mass. Of them, 83 patients had limited disease (LD) and 39 extensive disease (ED). Using CE-CAP alternating chemotherapy, 48 LD and 27 ED were given two cycles, 35 LD and 12 ED four cycles. In this series, remission time was not evaluated because all patients received radiotherapy shortly after chemotherapy. Of 122 patients, 10 patients (8.2%) achieved CR, 89 (72.9%) PR, 18 (14.7%) S and 5 (4%) P. The total response rate was 81.1% (99/122), which is higher than that of COMVP and PE-CAV regimens. The response rates were 80.0% and 82.9% in two and four cycle groups, respectively. There was no significant difference between the two groups. The main toxicity observed was nausea, vomiting and bone marrow suppression, but were tolerated by the patients. In conclusion, CE-CAP regimen can be recommended as the treatment of choice in SCLC.
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Liu YF, Yang SJ, Yan PS, Liu YY. Characteristics of immunocomplex in autopsy tissues of hemorrhagic fever with renal syndrome. Chin Med J (Engl) 1994; 107:444-9. [PMID: 7956485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Using repeated PAP or repeated PAP and ABC immunocytochemical methods, we were able to demonstrate viral antigens, Ig and Clq in the tissues of 20 autopsy materials that had been preserved for 3-30 years. Serial paraffin sections were stained with the first antibodies against both viral antigens (G2 and Np) and human IgG, IgM, C3 and Clq. Immunocomplex, composed of viral antigen, IgG and Clq were found diffusely in the cells of each organ and extracellularly in the sera, various secretions and exudates. When stained by A25 etc, coarse granular antigen or inclusion bodies were found without demonstrable Ig and Clq. It was concluded that the immunocomplex in tissues of epidemic hemorrhagic fever in Shaanxi Province, China was both intracellular and extracellular and was perhaps soluble due to antigens in excess, with characteristics quite different from that of other immune diseases.
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Liu YY, Shigematsu Y, Bykov I, Nakai A, Kikawa Y, Fukui T, Sudo M. Abnormal fatty acid composition of lymphocytes of biotin-deficient rats. J Nutr Sci Vitaminol (Tokyo) 1994; 40:283-8. [PMID: 7965217 DOI: 10.3177/jnsv.40.283] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The relative proportions (% of total fatty acids) of odd-chain (15:0-29:0) and long-chain (22:0-30:0) saturated fatty acids in phospholipids of biotin-deficient rat lymphocytes were significantly increased as compared with biotin-supplemented rats, and the ratio of unsaturated fatty acids to saturated fatty acids in the former was significantly decreased mainly due to the reduced composition of polyunsaturated fatty acids in the omega-3, omega-6, and omega-9 pathway. The ratio of cis-vaccenic acid to palmitoleic acid in biotin-deficient rats was significantly lower than that in control rats, and was thought to be another important, but previously unreported indicator of biotin deficiency. These changes imply that the elongation and desaturation of unsaturated fatty acids are depressed in lymphocytes of biotin-deficient rats, and may contribute to the associated immunological dysfunction in biotin deficiency through abnormal prostaglandin metabolism and/or cell membrane functions.
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238
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Suzuki H, Suematsu M, Miura S, Liu YY, Watanabe K, Miyasaka M, Tsurufuji S, Tsuchiya M. Rat CINC/gro: a novel mediator for locomotive and secretagogue activation of neutrophils in vivo. J Leukoc Biol 1994; 55:652-7. [PMID: 8182343 DOI: 10.1002/jlb.55.5.652] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The effects of rat CINC/gro, a member of the interleukin-8 family, on the endothelium-neutrophil interaction and transendothelial macromolecular leakage were studied in rat mesenteric microcirculation. Thirty minutes after superfusion with 10 nM CINC/gro, the number of neutrophils adherent to the venular endothelium and those migrated across the venules were significantly increased with a concomitant elevation of luminol-dependent chemiluminescence at the site of adhesion. Transendothelial macromolecular leakage as assessed by the relative length of venular wall stained with monastral blue B was also increased at 30 min after the start of CINC/gro superfusion. Pretreatments with a CD18-directed monoclonal antibody, WT-3 (1 mg/kg), significantly attenuated the increase in number of adherent and migrated neutrophils, the increase in luminol-dependent chemiluminescence, and the venular macromolecular leakage after the application of CINC/gro. These data suggest that CINC/gro is a novel stimulator that evokes not only locomotive but also secretagogue activation of neutrophils via a CD18-dependent mechanism in vivo.
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239
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Haruki M, Noguchi E, Nakai C, Liu YY, Oobatake M, Itaya M, Kanaya S. Investigating the role of conserved residue Asp134 in Escherichia coli ribonuclease HI by site-directed random mutagenesis. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 220:623-31. [PMID: 8125123 DOI: 10.1111/j.1432-1033.1994.tb18664.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The role of the conserved Asp134 residue in Escherichia coli ribonuclease HI, which is located at the center of the alpha V helix and lies close to the active site, was analyzed by means of site-directed random mutagenesis. Mutant rnhA genes encoding proteins with ribonuclease H activities were screened by their ability to suppress the ribonuclease-H-dependent, temperature-sensitive growth phenotype of E. coli strain MIC3001. Based on the DNA sequences, nine mutant proteins were predicted to have ribonuclease H activity in vivo. All of these mutant proteins were purified to homogeneity and examined for enzymic activity and protein stability. Among them, only the mutant proteins [D134H]RNase H and [D134N]RNase H were shown to have considerable ribonuclease H activities. Determination of the kinetic parameters revealed that replacement of Asp134 by amino acid residues other than asparagine and histidine dramatically decreased the enzymic activity without seriously affecting the substrate binding. Determination of the CD spectra indicated that none of the mutations seriously affected secondary and tertiary structure. The protein stability was determined from the thermal denaturation curves. All mutant proteins were more stable than the wild-type protein. Such stabilization effects would be a result of a reduction in the negative charge repulsion between Asp134 and the active-site residues, and/or an enhancement of the stability of the alpha V helix. These results strongly suggest that Asp134 does not contribute to the maintenance of the molecular architecture but the carboxyl oxygen at its delta 1 position impacts catalysis.
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240
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Zhou JG, Miao YG, Liu YY. New geometrical insight into the anomalies in string theory. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1994; 49:2129-2132. [PMID: 10017199 DOI: 10.1103/physrevd.49.2129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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241
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Shigematsu Y, Nakai A, Liu YY, Kikawa Y, Sudo M, Fujioka M. Free carnitine and short-chain acylcarnitines in cerebrospinal fluid of patients with disorders of propionate metabolism determined by fast atom bombardment and tandem mass spectrometry. ACTA PAEDIATRICA JAPONICA : OVERSEAS EDITION 1994; 36:112-5. [PMID: 8165900 DOI: 10.1111/j.1442-200x.1994.tb03143.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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242
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Hu JF, Liu YY, Yu YK. [Estimation of latency period of lung cancer]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 1994; 16:18-21. [PMID: 8033741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A case-control study with time-related factors was conducted to estimate the latency period of lung cancer. This study included 168 incident male cases of lung cancer histologically confirmed and 336 control patients with non-neoplastic diseases. All patients were interviewed in the hospital wards from May 1987 to May 1990. Data concerning smoking, occupation, method of house heating and cooking fuel used from twelve time windows of looking forward and diet were obtained for three periods of time. A synthetical analysis of forward measures and backward measures were applied. By means of calculating accumulated effective exposure score and excess exposure fraction, the latency period of lung cancer was estimated using multivariate model. Latency of lung cancer is 54.48 years for indoor air pollution, and 56.17 years for total smoking. From estimating latency period of lung cancer from multivariate analysis, it was found that the latency of lung cancer could be affected by the effects of other factors. Therefore, measures which prolong latency period may be of use in the prevention of lung cancer.
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Shigematsu Y, Bykov IL, Liu YY, Nakai A, Kikawa Y, Sudo M, Fujioka M. Acylcarnitine profile in tissues and body fluids of biotin-deficient rats with and without L-carnitine supplementation. J Inherit Metab Dis 1994; 17:678-90. [PMID: 7707691 DOI: 10.1007/bf00712010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Since biotin-deficient (BD) rats are a good animal model for human multiple carboxylase deficiency and have low plasma free carnitine levels, short-chain acylcarnitine profiles in biotin-deficient rats with L-carnitine supplementation (BDC rats) and BD rats were investigated by fast-atom bombardment and tandem mass spectrometry and gas chromatography/mass spectrometry. By the latter method, 3-hydroxyisovalerylcarnitine was identified in BD rats, and showed the greatest accumulation among short-chain acylcarnitines in tissues of BD rats, while the tissue levels of propionic acid were more markedly elevated than those of 3-hydroxyisovaleric acid. The tissue levels of 3-hydroxyisovaleryl-carnitine were significantly lower and those of propionyl-carnitine were somewhat higher in BDC rats than in BD rats, while the tissue levels of propionic acid and 3-hydroxyisovaleric acid in BDC rats were lower than those in BD rats. These changes were more apparent in kidney than in other tissues. The amounts of urinary excretion of acylcarnitines were markedly larger, and those of 3-hydroxyisovaleric acid were somewhat smaller in BDC rats than in BD rats, while those of propionic acid were very low in BD and BDC rats as compared with those of 3-hydroxyisovaleric acid. It seems that the relationship between the concentrations of 3-hydroxyisovalerylcarnitine and those of propionylcarnitine reflects the unique metabolism of the related metabolites in tissues, especially in kidney, which may be influenced by their urinary excretion and the availability of free carnitine. These data in biotin deficiency suggest that carnitine supplementation is possibly beneficial for patients with holocarboxylase synthetase deficiency who respond incompletely to biotin therapy.
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Liu YY, Shigematsu Y, Nakai A, Kikawa Y, Saito M, Fukui T, Hayakawa K, Oizumi J, Sudo M. The effects of biotin deficiency on organic acid metabolism: increase in propionyl coenzyme A-related organic acids in biotin-deficient rats. Metabolism 1993; 42:1392-7. [PMID: 8231832 DOI: 10.1016/0026-0495(93)90188-t] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Volatile organic acid levels in plasma and tissues and nonvolatile organic acid levels in urine of biotin-deficient (BD) rats were measured and compared with other factors of biotin deficiency. Biotin levels and the activities of propionyl coenzyme A (CoA) carboxylase (PCC) in the livers of these rats were decreased, respectively, to 22% +/- 3% and 3.6% +/- 0.3% of the average values of pair-fed controls. Plasma concentrations of propionate were higher (15 to 223 micrograms/mL) than those of controls (5 to 7 micrograms/mL), whereas plasma levels of 3-methylcrotonate were only minimally increased as compared with those of controls. Concentrations of these volatile acids in the tissues were similarly increased, although those in brain showed less remarkable increases as compared with levels in other tissues. In the urine of BD rats, large amounts of organic acids derived from propionyl CoA, as well as those from 3-methylcrotonyl CoA, were excreted. Plasma propionate levels were not apparently related to the severity of clinical symptoms, biotin levels, or carboxylase activities, but were related to the amounts of urinary ketone bodies, lactate, and some of the organic acids derived from branched-chain amino acids, including those from propionyl CoA.
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Fischman AJ, Livni E, Babich J, Alpert NM, Liu YY, Thom E, Cleeland R, Prosser BL, Correia JA, Strauss HW. Pharmacokinetics of [18F]fleroxacin in healthy human subjects studied by using positron emission tomography. Antimicrob Agents Chemother 1993; 37:2144-52. [PMID: 8257137 PMCID: PMC192242 DOI: 10.1128/aac.37.10.2144] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Positron emission tomography (PET) with [18F]fleroxacin was used to study the pharmacokinetics of fleroxacin, a new broad-spectrum fluoroquinolone, in 12 healthy volunteers (9 men and 3 women). The subjects were infused with a standard therapeutic dose of fleroxacin (400 mg) supplemented with approximately 20 mCi of [18F]fleroxacin. Serial PET images were made and blood samples were collected for 8 h, starting at the initiation of the infusion. The subjects were then treated with unlabeled drug for 3 days (400 mg/day). On the fifth day, infusion of radiolabeled drug, PET imaging, and blood collection were repeated. In most organs, there was rapid accumulation of radiolabeled drug, with stable levels achieved within 1 h after completion of the infusion. Especially high peak concentrations (in micrograms per gram) were achieved in the kidney (> 34), liver (> 25), lung (> 20), myocardium (> 19), and spleen (> 18). Peak concentrations of drug more than two times the MIC for 90% of Enterobacteriaceae strains tested (> 10-fold for most organisms) were achieved in all tissues except the brain and remained above this level for more than 6 to 8 h. The plateau concentrations in tissues (2 to 8 h, in micrograms per gram +/- standard error of the mean) of drug were as follows: brain, 0.83 +/- 0.032; myocardium, 4.53 +/- 0.24; lung, 5.80 +/- 0.48; liver, 7.31 +/- 0.33; spleen, 6.00 +/- 0.47; bowel, 3.53 +/- 0.74; kidney, 8.85 +/- 0.64; bone, 2.87 +/- 0.29; muscle, 4.60 +/- 0.33; prostate, 4.65 +/- 0.48; uterus, 3.87 +/- 0.39; breast, 2.68 +/- 0.11; and blood, 2.35 +/- 0.09. Concentrations of fleroxacin in tissue were similar in males and females, before and after pretreatment with unlabeled drug.
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Zhou JG, Li SM, Liu YY. Dependence of the Gauss-law constraints on the regularization scheme in non-Abelian chiral gauge theory. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1993; 48:961-963. [PMID: 10016331 DOI: 10.1103/physrevd.48.961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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247
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Itoh M, Nakayama S, Liu YY, Kawaguchi Y. Building areas of hospitals in Japan and distribution of areas by department--1980's. JAPAN-HOSPITALS : THE JOURNAL OF THE JAPAN HOSPITAL ASSOCIATION 1993; 12:9-22. [PMID: 10128171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
(1) Areas of entire hospitals which have been continuously increasing in the past 30 years are finally showing signs for slowing down. The areas of the hospitals completed in the 1980's were generally 50 to 80 m2 per bed. (2) The distribution of the nursing department to the entire hospitals in area ratio ranges from 30 to slightly more than 40%, or higher than 35% in most cases. The actual areas of the nursing department has surpassed 20 m2 per bed in a considerably large number of hospitals. (3) The area ratio of the outpatient department tends to concentrate to about 12%. Of this percentage, in almost all hospitals, the proportion of the emergency division was less than 2%. (4) As in the 1970's, the diagnostic and treatment facilities were within the range of 18 to 22% in the majority of the hospitals. The distribution shifted to ratios higher than the previous survey. The distributions for the various sections are as follows: 1) Specimen test rooms 3 to 5% 2) Physiological examination rooms slightly below 1% to slightly above 2% 3) X-ray diagnosis rooms about 4% 4) Radiation therapy rooms about 1% 5) Nuclear medicine rooms about 1% 6) Operating department 3 to 5%, 2 to 3 m2/bed 7) Delivery suite less than 1% 8) Rehabilitation department 1 to 4% 9) Hemodialysis suite about 1% (5) The area ratios of the supply department dispersed substantially between 12 and 25%. About 70% of the hospitals remained in the range of 15 to 20%. The ratios of the various sections in the department are as follows: 1) Pharmacy: slightly less than 2% to slightly less than 3% 2) Central sterile and supply department: about 2% 3) Blood bank: installed in hospitals with more than 500 beds 4) Kitchen: slightly more than 2% to slightly more than 3%, 1.5 to 2.5 m2/bed 5) Laundry: less than 1% 6) Central storage and material hundling unit: about 1% 7) Mechanical plant: 5 to 13% (6) The administration department allocates 7 to 14% of its area to the management division and 2 to 6% to the welfare division.
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Liu YY, Cooper JI. The multiplication in plants of arabis mosaic virus satellite RNA requires the encoded protein. J Gen Virol 1993; 74 ( Pt 7):1471-4. [PMID: 7687652 DOI: 10.1099/0022-1317-74-7-1471] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Oligonucleotide-directed mutagenesis was used to create two mutations at each of three positions within the open reading frame (ORF) of a cDNA clone representing a satellite RNA from a lilac isolate of arabis mosaic nepovirus (ArMV). Three of the six mutants, in which stop codons were introduced at three different sites, did not direct synthesis of a translation product. The other three mutants, in which stop codons were not introduced, directed synthesis of a translation product (39K) although, in two of these, the mutation led to a single amino acid substitution. When Chenopodium quinoa plants were inoculated with in vitro transcripts from each of the six mutants together with the genomic RNA molecules (RNA-1 and RNA-2) of ArMV, progeny RNA was detected only with two of the three mutants in which the nucleotide changes did not introduce a stop codon to the coding region. To look for complementation, two deletion mutants were made. In these, 113 or 117 nucleotides were removed from two consecutive regions within the ORF. Two insertion mutants (in which the deleted sequences were replaced with a 130 nucleotide sequence from RNA-2 of cherry leaf roll nepovirus) were also made. Transcripts from none of these mutants retained messenger activity and none was detected either in C. quinoa plants or in virions, even in the presence of wild-type satellite RNA.
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Henry JP, Liu YY, Nadra WE, Qian CG, Mormede P, Lemaire V, Ely D, Hendley ED. Psychosocial stress can induce chronic hypertension in normotensive strains of rats. Hypertension 1993; 21:714-23. [PMID: 8491506 DOI: 10.1161/01.hyp.21.5.714] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We report on five 6-month experiments during which five colonies of four male and four female rats were exposed to psychosocial stress. Monthly blood pressure measurements by a tail-cuff method showed a modest (10 mm Hg) increase in two studies using Sprague-Dawley rats. In two further studies using the more aggressive Long-Evans strain, terminal direct carotid arterial pressures were taken as well, and in one study the differences exceeded 20 mm Hg. A fifth study used the Wistar-Kyoto, hyperactive (WKHA) strain developed by Hendley, and no differences were observed. Heart and adrenal weights; adrenal catecholamine synthetic enzymes; and heart, aortic, and kidney histology were measured and showed significant changes, which for the most part paralleled blood pressure changes. Social instability and the associated blood pressure changes were made more severe by periodic mixing of males from different colonies. This had no effect on the peaceable WKHA rats, some effect on the Sprague-Dawley rats, and a severe effect on the Long-Evans rats. The WKHA rats failed to show blood pressure changes despite stress-induced increases in heart and adrenal weights. Thus, different types of psychosocial stress and different genetics combine to induce a variety of neuroendocrine changes, not all of which necessarily lead to increased blood pressure.
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Rubin RH, Livni E, Babich J, Alpert NM, Liu YY, Tham E, Prosser B, Cleeland R, Callahan RJ, Correia JA. Pharmacokinetics of fleroxacin as studied by positron emission tomography and [18F]fleroxacin. Am J Med 1993; 94:31S-37S. [PMID: 8452183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A new method of tracing the disposition of fleroxacin was tested in infected and noninfected animals in an effort to develop a technique that might be applicable in humans. [18F]fleroxacin was synthesized and shown to be identical physically, chemically, and in its antimicrobial activity to the commercially produced product. Tracer amounts of [18F]fleroxacin were coinjected with a pharmacologic dose of unlabeled drug (10 mg/kg) into normal mice, rats with focal thigh infection due to Escherichia coli, and normal and infected rabbits. The rats and mice were killed at fixed time intervals after injection, and the concentration of drug was determined by radioactive counting in a well-type counter; the rabbits were studied both by this method and by positron emission tomographic (PET) imaging. These studies validated the reliability of the new approach and suggested that it could be applied safely to humans. In all three animal species studied, delivery of [18F]fleroxacin to most tissues was rapid, with the notable exception of the brain. Accumulation of drug in infected thigh muscle was similar to that in normal muscle. The concentrations of drug reached in various tissues suggest that fleroxacin will be particularly useful in the treatment of gastrointestinal, urinary tract, hepatobiliary, and skeletal infections and that it shows promise for the treatment of lung and soft tissue infection. The minimal concentrations of drug delivered to the brain should decrease the occurrence of central nervous system toxicity with this particular fluoroquinolone.
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