701
|
Pappo AS, Bowman LC, Furman WL, Rao BN, Kun LE, Jenkins JJ, Crom WR, Luo X, Kaste SC, Avery L, Meyer WH, Shapiro DN, Crist WM. A phase II trial of high-dose methotrexate in previously untreated children and adolescents with high-risk unresectable or metastatic rhabdomyosarcoma. J Pediatr Hematol Oncol 1997; 19:438-42. [PMID: 9329466 DOI: 10.1097/00043426-199709000-00006] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE The outcome for children with advanced-stage rhabdomyosarcoma remains poor with contemporary treatment regimens. Evaluation of new drugs is important to improve clinical outcome. Because methotrexate has shown promising activity in the treatment of patients with recurrent rhabdomyosarcoma, we conducted a phase II trial in untreated children with advanced-stage disease to evaluate the efficacy and safety of this agent. PATIENTS AND METHODS Fifteen patients received 1 to 4 courses of high-dose methotrexate (HDMTX, 12 g/m2). Patients then received standard multiagent chemotherapy (vincristine, dactinomycin, cyclophosphamide, ifosfamide, mesna) with cytokine support and local radiotherapy. Patients who responded to HDMTX received four additional courses of this drug during continuation therapy. RESULTS Twelve patients were evaluable for response after 2 or more courses of HDMTX; 4 achieved a partial response (33.3%). After administration of standard chemotherapy and radiation, the estimated 2-year progression-free survival for all patients was 56% (SD 15%). The drug was well-tolerated and the most common side effects included mucositis, transient elevation of transaminases, and neutropenia. The four patients who received additional courses of HDMTX during continuation therapy had limited toxicity which included mucositis, anemia, and thrombocytopenia. CONCLUSIONS About one-third of children with previously untreated advanced-stage rhabdomyosarcoma responded to HDMTX. Its different mechanism of action and non-overlapping toxicity with other agents make HDMTX an attractive candidate for incorporation into front-line treatment regimens for rhabdomyosarcoma.
Collapse
|
702
|
Michalkiewicz EL, Rao BN, Gross E, Luo X, Bowman LC, Pappo AS, Kaste SC, Hudson MM, Greenwald CA, Jenkins JJ, Pratt CB. Complications of pelvic exenteration in children who have genitourinary rhabdomyosarcoma. J Pediatr Surg 1997; 32:1277-82. [PMID: 9314242 DOI: 10.1016/s0022-3468(97)90301-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Rhabdomyosarcoma is the most frequently encountered soft tissue sarcoma in children younger than 15 years of age. METHODS The authors reviewed the early and long-term morbidity rate and clinical outcome of pelvic exenteration for genitourinary rhabdomyosarcoma (GU-RMS) in children. Of 43 patients with this diagnosis who were seen at St Jude Children's Research Hospital between 1963 and 1994, 17 underwent pelvic exenteration. These 13 boys and four girls ranged in age from 6 months to 15 years (median, 3.5 years). Their primary sites included prostate (n = 12), bladder (n = 4), and uterus (n = 1). All patients received multiagent chemotherapy and either preoperative or postoperative radiation therapy. Anterior exenteration was performed in 15 patients and total exenteration in two. The complications were classified as early or late (occurring within or after 30 days from the date of surgery) and as major or minor (depending on the risk of death or physical or functional disability). RESULTS Thirteen of the 17 patients (76%) had 49 surgery-related complications. Wound infection (24%), fistula, abscess, and malnourishment (12% each) were the most common early major complications, with hydronephrosis (35%), bowel obstruction (24%), acute pyelonephritis, fistula, lymphedema, and ureter stenosis (12% each) making up the majority of late complications in this category. Relatively frequent minor complications included protracted paralytic ileus and hematuria (18%), cholelithiasis, chronic diarrhea and, peristoma skin irritation (12%). Disease-free survival was associated with the timing of surgery (P = .002). All but one of the 12 patients who underwent surgery within 6 months of diagnosis are alive, compared with only one of five whose surgery was performed after a longer interval. Pelvic exenteration for GU-RMS was associated with a high rate of serious complications in this series of patients treated over 31 years. CONCLUSION With recent advances in surgical techniques, as well as improvements in preoperative and postoperative care, this procedure should continue to be applied in cases resistant to conventional therapy.
Collapse
|
703
|
Zhang H, Luo X, Wang Z. [Limb salvage and amputation in osteosarcoma: report of 31 cases]. ZHONGHUA WAI KE ZA ZHI [CHINESE JOURNAL OF SURGERY] 1997; 35:556-7. [PMID: 10678034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Three different types of operation were performed in 31 osteosarcoma patients, and some cases received chemotherapy. It revealed, wide resection of tumor supplemented with chemotherapy improved the survival and limb salvage rate enormously. Chemotherapy and wide resection were all absolutely essential. The life of prosthesis was long and most patients were satisfied with it. Chemotherapy and limb salvage can enhance the survival and life quality in patients with osteosarcoma.
Collapse
|
704
|
Luo X, Wei H, Liu S. [Cell culture of human lamina cribrosa in vitro]. [ZHONGHUA YAN KE ZA ZHI] CHINESE JOURNAL OF OPHTHALMOLOGY 1997; 33:357-9. [PMID: 10451981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
OBJECTIVE To investigate the physiology and pathology of the biosynthesis of extracellular matrix (ECM) by lamina cribrosa cells (LCC) and to establish a model of cultured LCC. METHODS The LCC of 10 human dead fetal eyes were cultured with enzyme digestion procedures in vitro. The cultured cells were identified by immunohistochemistry assays and electron microscopy. RESULTS The cultured cells were flat, polygonal in shape, and their cytoplasm contained abundant perinuclear granules. The nuclei were relatively transparent and nucleoli were clear, there were basement membrane-like material and ECM surrounding the cell membrane. The immunofluorescent staining was positive for collagen type I, III, IV, fibronectin and laminin, negative for glial fibrillar acid protein and factor-VIII. The characteristics mentioned above were coincident with the morphology of LCC. This cell line has been cultured to its fourth generation. CONCLUSION We have successfully cultured a cell line of LCC, and it may be utilized in the study of pathogenesis of glaucoma.
Collapse
|
705
|
Luo X, Jia A, Ma G. [Fabrication and use of two kinds of overdenture attachments]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 1997; 15:233-5. [PMID: 11480007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
The authors introduced the fabrication of stud attachment and bar attachment used to increase the stability and retention of overdenture. During two years' periods, the results of the clinical practice indicated: the retention of overdenture was increased and patients' masticator function was improved when attachments were used, and then the fabrications of two kinds of attachments were simple and value of attachments is cheap. The technique was popularized and used easily.
Collapse
|
706
|
Johnson SM, Luo X, Bywood PT. Neurotoxic effects of kainic acid on substantia nigra neurons in rat brain slices. Exp Neurol 1997; 146:546-52. [PMID: 9270066 DOI: 10.1006/exnr.1997.6578] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Excitatory amino acids (EAAs) have been implicated as mediators of cell death in neurodegenerative diseases involving catecholamine neurons. Few studies, however, have examined the toxic effects of EAAs on identified catecholamine neurons in vitro. We have investigated the neurotoxic effects of kainic acid in a rat brain substantia nigra (SN) slice preparation. Rats (60-80 g) were anesthetised with halothane and killed by cervical dislocation. SN slices, 300 microm thick, were incubated at 35 degrees C in a modified Krebs solution in the presence or absence of kainic acid and then fixed and processed for either immunohistochemistry (IHC) or electron microscopy (EM). In IHC experiments, SN neurons were labeled using antibody to tyrosine hydroxylase (TH) coupled to diaminobenzidine. In control slices, the antibody labeled not only the cell body but also the prolific dendritic arbor of SN neurons. Treatment with 50 microM kainic acid for 15 min or 2 h resulted in loss of TH staining and apparent fragmentation of the dendrites. EM provided ultrastructural evidence for kainic acid-induced degeneration of the dendritic arbor of SN neurons. Typically, the dendritic membrane was broken, or diffuse and collapsed. Ultrastructural damage, including clumping and marginalization of chromatin and vacuolation of the cytoplasm, was also observed in cell bodies. Damage to the dendritic arbor may occur early in the neurotoxic events leading to cell death, preceding the loss of the cell body. Our observations are consistent with the postulated role of EAAs as mediators of catecholamine neuron death.
Collapse
|
707
|
Wang QM, Luo X, Studzinski GP. Cyclin-dependent kinase 6 is the principal target of p27/Kip1 regulation of the G1-phase traverse in 1,25-dihydroxyvitamin D3-treated HL60 cells. Cancer Res 1997; 57:2851-5. [PMID: 9230188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Control of cell proliferation remains of intense interest in cancer research. In the 1,25-dihydroxyvitamin D3 HL60 cell system, G1 arrest has been shown to be mediated by elevated levels of p27/Kip1 protein. We show here that the main target of the elevated p27/Kip1 in this system is cyclin-dependent kinase (Cdk) 6. The activity of Cdk2 is also down-regulated, and this is associated with altered and reduced levels of cyclin E in the kinase complex. Paradoxically, the kinase activity of Cdk4 is elevated, in spite of an almost complete G1 block. These data show that the functions of Cdk4 and Cdk6 are not redundant and that Cdk6 and Cdk2 activities are regulated by 1,25-dihydroxyvitamin D3.
Collapse
|
708
|
Tan X, Li S, Luo X, Zhou Y. [Molecular mechanism of mutagenesis induced by aflatoxin B1 using a shuttle vector pSP189/mammalian cell system]. WEI SHENG YAN JIU = JOURNAL OF HYGIENE RESEARCH 1997; 26:271-7. [PMID: 10325601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
AFB1 is one of the most potent carcinogenic mycotoxins, naturally occurred in foods. We applied a new SV40-based shuttle vector pSP189 and African Green kidney cells (VeroE6 cell line), which constitute shuttle vector/mammalian cell system to detect mutagenesis induced by AFB1 and to study the effects of AFB1 on the mutation site, type and sequence specificity of DNA molecular level through sequence analysis of pSP189 target gene SupF TRNA. The results indicated that through various time treatment of AFB1 and rat liver microsome, the mutants were obtained by transformation of E. Coli MBM 7070 with progeny of pSP189 generated during replication in veroE6 cells, which increased gradually with the lapse of time, and this experiment showed a significant dose-response relationship. Most detected mutants were point mutations evidenced by agarose gel electrophoresis analysis. The results of direct sequencing SupF TRNA of 53 independent mutants showed that most mutations (about 84.9%) were single base substitutions, among which 95.2% of base substitutions happened on the site of G:C base pair, the predominant mutation was G:C-->T:A transversion, accounting for 53.3%, followed by G:C-->A:T transition, accounting for 35.6%. AFB1-induced mutations did not distributed randomly, and had mutation hot spots and sequence specificity, which contained 5 base pair sequence 5'-NNTTC-3'. The mutations on the SupF shuttle vector were consistent with the results from studies of oncogene tumor suppressor genes and DNA adduct.
Collapse
|
709
|
Wilimas JA, Kaste SC, Kauffman WM, Winer-Muram H, Morris R, Luo X, Boyett JM. Use of chest computed tomography in the staging of pediatric Wilms' tumor: interobserver variability and prognostic significance. J Clin Oncol 1997; 15:2631-5. [PMID: 9215834 DOI: 10.1200/jco.1997.15.7.2631] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
PURPOSE To determine the specificity and prognostic significance of computed tomography (CT) of the chest in pediatric Wilms' tumor. PATIENTS AND METHODS Patients treated for newly diagnosed Wilms' tumor at St Jude Children's Research Hospital between December 1978 and July 1995 were included in the study if an initial chest radiograph and CT were available and if pulmonary involvement (determined by chest radiographs) was absent. For the 202 patients studied, radiographs and CT scans were reviewed blindly and independently by three experienced radiologists for the presence of pulmonary nodules. Outcome variables consisted of intraobserver variability (in a subsample of 40 cases) and concordance between ratings on radiographs and CT scans (both by McNemar's test), interrater variability (by logistic regression), and the cumulative incidence of pulmonary relapse for patients with and without positive CT scans, by reviewer. RESULTS As expected, ratings of pulmonary involvement on radiographs were discordant with CT ratings. There was marked variability among reviewers in CT ratings (P = .0001). Of 202 CT scans, 78 were read as positive by at least one reviewer, 41 were rated positive by only one reviewer, 18 by two reviewers, and 19 by all three. Intrarater variability on repeat reviews was not significant. Patients with nodules identified on CT had a significantly higher pulmonary relapse rate when analyzed separately by reviewer. However, for the 14 patients who had pulmonary relapse, CT scans were rated positive by all three reviewers in only five cases and as negative by all three in another five cases. CONCLUSION The variability in interpretation of chest CT scans in patients with Wilms' tumor limits the predictive utility of these studies. Optimal, standardized techniques and central review are essential if chest CT is to be used for staging in cooperative studies.
Collapse
|
710
|
Luo X, Pitkänen S, Kassovska-Bratinova S, Robinson BH, Lehotay DC. Excessive formation of hydroxyl radicals and aldehydic lipid peroxidation products in cultured skin fibroblasts from patients with complex I deficiency. J Clin Invest 1997; 99:2877-82. [PMID: 9185510 PMCID: PMC508138 DOI: 10.1172/jci119481] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Previous studies suggest oxygen free radicals' involvement in the etiology of cardiomyopathy with cataracts. To investigate the role of free radicals in the pathogenesis of the cardiomyopathy with cataracts and complex I deficiency, fibroblasts from patients were assessed for hydroxyl radical formation and aldehydic lipid peroxidation products with and without redox active agents that increase free radicals. The rate of hydroxyl radical formation in patient cells was increased over 2-10-fold under basal conditions, and up to 20-fold after menadione or doxorubicin treatment compared with normal cells. We also found an overproduction of aldehydes in patient cells both under basal conditions and after treatment. Both hydroxyl radicals and toxic aldehydes such as hexanal, 4-hydroxynon-2-enal, and malondialdehyde were elevated in cells from patients with three types of complex I deficiency. In contrast, acyloins, the less toxic conjugated products of pyruvate and saturated aldehydes, were lower in the patient cells. Our data provide direct evidence for the first time that complex I deficiency is associated with excessive production of hydroxyl radicals and lipid peroxidation. The resultant damage may contribute to the early onset of cardiomyopathy and cataracts and death in early infancy in affected patients with this disease.
Collapse
|
711
|
Luo X, Huang Y, Hayes JK, Wong KC, Yee JB, McJames S. Effects of dobutamine, epinephrine and norepinephrine on the hemodynamics of dogs during hemorrhagic shock. ACTA ANAESTHESIOLOGICA SINICA 1997; 35:61-71. [PMID: 9293645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND The present study examined how effective epinephrine (EPI), norepinephrine (NOR) and dobutamine (DOB) were for resuscitating dogs subjected to hemorrhagic shock (HS). METHODS Dogs (n = 42) were randomly assigned to seven test groups: EPI, NOR and DOB infusion with and without HS, and HS dogs with no catecholamine. Following baseline measurements, the dogs were bled to a mean arterial blood pressure of 40 mmHg. After 3 h, the shed blood was reinfused. EPI and NOR (0.1, 0.4 and 1.6 micrograms/kg/min) and DOB (2.5, 5.0 and 10.0 micrograms/kg/min) were given and the dog allowed to stabilize for 30 min. Hemodynamic and blood gas data were obtained at 6 time points (control, shock, resuscitation and after catecholamine infusion). RESULTS There was no significant difference in myocardial performance (dP/dt) between the respective shocked and unshocked groups after blood resuscitation. In dogs without catecholamine infusion, CO and SvO2 continued to decline whereas SVR increased. DOB (2.5 to 10.0 micrograms/kg/min) with and without shock improved CO, LV dP/dt, SVR and SvO2. EPI did not further improve CO or SvO2 at infusion rates above 0.1 microgram/kg/min (with and without shock). NOR did not improve SvO2 at any infusion rate (with and without shock) and did not improve CO until the infusion rate was at 0.4 microgram/kg/min (without shock). CONCLUSIONS This study advocates the use of both volume replacement therapy and DOB for resuscitation of HS dogs.
Collapse
|
712
|
Resnick MS, Luo X, Vinton EG, Sando JJ. Selective up-regulation of protein kinase C eta in phorbol ester-sensitive versus -resistant EL4 mouse thymoma cells. Cancer Res 1997; 57:2209-15. [PMID: 9187123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Stimulation of sensitive EL4 mouse thymoma cells (s-EL4) with phorbol esters results in production of interleukin 2 (IL-2), adherence to a plastic substrate, and growth inhibition, whereas a phorbol ester-resistant variant (r-EL4) fails to respond. Previous studies revealed substantially decreased expression of protein kinase C (PKC) epsilon in the r-EL4 versus s-EL4 cells. This work has been extended to examine the more recently described PKC isozymes. Western and Northern analyses revealed a marked decrease in PKC eta and theta in r-EL4 as compared to s-EL4 cells. Treatment of these lines with phorbol ester for 24 h resulted in down-regulation of all PKC isozymes examined except PKC eta, which was up-regulated in the s-EL4 cells at the time of maximal IL-2 production. Two newly isolated EL4 clones, resistant to phorbol ester-induced growth inhibition but still exhibiting the phorbol ester-induced adherence and IL-2 production, both expressed PKC eta and theta. Collectively, these observations suggest a dissociation of growth inhibition from adherence and IL-2 production pathways and a potential role for PKC eta in the latter.
Collapse
|
713
|
Liu Z, Yan W, Xu H, Zheng L, Luo X. [Homology analysis of RubisCO gene of Thiobacillus versutus with extremelly acidophilic thiobacilli]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 1997; 37:179-83. [PMID: 9863211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The chromosomal DNA of Thiobacillus thiooxidans and T. versutus was digested with restriction enzymes, blotted to nylon membrane by the way of Southern, and hybridized with the gene probe of ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) from T. ferrooxidans. The result showed that T. thiooxidans exhibited high homology with the probe anc T. versutus was less homology with it. However T. versutus can hybridize with the gene probe of RubisCO from Rhodobacter sphaeroides, which indicated that they had high homology with each other. As RubisCO was highly reserved in the evolutionary, they should be divided into different group.
Collapse
|
714
|
Furman WL, Luo X, Fairclough D, Garrison L, Marina N, Pratt CB, Bleyer A, Meyer WH. Phase I trial of subcutaneous interleukin-1 alpha in children with malignant solid tumors. MEDICAL AND PEDIATRIC ONCOLOGY 1997; 28:444-50. [PMID: 9143391 DOI: 10.1002/(sici)1096-911x(199706)28:6<444::aid-mpo10>3.0.co;2-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Interleukin-1 alpha (IL-1 alpha) is myeloprotective in a variety of animal models of cancer chemotherapy and is similarly beneficial in adults treated with carboplatin, 5-fluorouracil, and after autologous bone marrow transplantation. There are no trials of this agent in children. Our purpose was to determine the toxicity and maximum tolerated dose (MTD) of recombinant human interleukin-1 alpha (rhuIL-1 alpha) in children with solid tumors receiving intensive cancer chemotherapy and to evaluate its myelo-protective effects. Cohorts of patients received rhuIL-1 alpha in doses of 0.1-10 micrograms/m2 for 4 days by subcutaneous injection prior to ICF chemotherapy (ifosfamide, 2 g/m2/day x 3, carboplatin targeted to an area under the curve of 8 mg/ml x min on day 1, and etoposide, 100 mg/m2 daily for 3 days). Patients were randomized to receive rhuIL-1 alpha before either the first or second course of therapy. After the MTD of rhuIL-1 alpha was determined an additional group of patients received rhuIL-1 alpha at the dose immediately following ICE chemotherapy. The dose-limiting toxicities of rhuIL-1 alpha in the 27 children tested comprised systemic symptoms of fever, chills, headache, and hypotension. The MTD was 3 micrograms/m2/day. There were no differences in chemotherapy-induced hematologic toxicity with increasing doses of rhuIL-1 alpha or in comparisons before or after ICE chemotherapy. Although rhuIL-1 alpha can be given safely to children receiving myelosuppressive chemotherapy, clinical usefulness would mandate a significant hematopoietic benefit in view of the trouble some side effects identified. We saw no evidence of a hematoprotective effect.
Collapse
|
715
|
Luo X, Sando JJ. Deficient tyrosine phosphorylation of c-Cbl and associated proteins in phorbol ester-resistant EL4 mouse thymoma cells. J Biol Chem 1997; 272:12221-8. [PMID: 9115297 DOI: 10.1074/jbc.272.18.12221] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Two tyrosine phosphoproteins in phorbol ester-sensitive EL4 (S-EL4) mouse thymoma cells have been identified as the p120 c-Cbl protooncogene product and the p85 subunit of phosphatidylinositol 3-kinase. Tyrosine phosphorylation of p120 and p85 increased rapidly after phorbol ester stimulation. Phorbol ester-resistant EL4 (R-EL4) cells expressed comparable amounts of c-Cbl and phosphatidylinositol 3-kinase protein but greatly diminished tyrosine phosphorylation. Co-immunoprecipitation experiments revealed complexes of c-Cbl with p85, and of p85 with the tyrosine kinase Lck in phorbol ester-stimulated S-EL4 but not in unstimulated S-EL4 or in R-EL4 cells. In vitro binding of c-Cbl with Lck SH2 or SH3 domains was detected in both S-EL4 and R-EL4 cells, suggesting that c-Cbl, p85, and Lck may form a ternary complex. In vitro kinase assays revealed phosphorylation of p85 by Lck only in phorbol ester-stimulated S-EL4 cells. Collectively, these results suggest that Cbl-p85 and Lck-p85 complexes may form in unstimulated S-EL4 and R-EL4 cells but were not detected due to absence of tyrosine phosphorylation of p85. Greatly decreased tyrosine phosphorylation of c-Cbl and p85 in the complexes may contribute to the failure of R-EL4 cells to respond to phorbol ester.
Collapse
|
716
|
Joo WS, Luo X, Denis D, Kim HY, Rainey GJ, Jones C, Sreekumar KR, Bullock PA. Purification of the simian virus 40 (SV40) T antigen DNA-binding domain and characterization of its interactions with the SV40 origin. J Virol 1997; 71:3972-85. [PMID: 9094674 PMCID: PMC191549 DOI: 10.1128/jvi.71.5.3972-3985.1997] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
To better define protein-DNA interactions at a eukaryotic origin, the domain of simian virus 40 (SV40) large T antigen that specifically interacts with the SV40 origin has been purified and its binding to DNA has been characterized. Evidence is presented that the affinity of the purified T antigen DNA-binding domain for the SV40 origin is comparable to that of the full-length T antigen. Furthermore, stable binding of the T antigen DNA-binding domain to the SV40 origin requires pairs of pentanucleotide recognition sites separated by approximately one turn of a DNA double helix and positioned in a head-to-head orientation. Although two pairs of pentanucleotides are present in the SV40 origin, footprinting and band shift experiments indicate that binding is limited to dimer formation on a single pair of pentanucleotides. Finally, it is demonstrated that the T antigen DNA-binding domain interacts poorly with single-stranded DNA.
Collapse
|
717
|
Jia A, Luo X, Ou Y. [Effect of stud attachment post design on dentin stress distribution]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 1997; 15:110-1, 134. [PMID: 11480022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
The shape design of attachment post is crucial factors influencing post retention and stress distribution to the dentin. By means of CAD and FEA, the present study investigated the effects of the shape designs of attachment posts on the stress distribution in dentin. The results indicated that the taper post had wedging effects on the dentin and produced higher Von Misses stress than that of parallel side post and the Von Misses stress value of the dentin was about 1.1 times. The maximum Von Misses stress value that the design of the thread post produced was about 1.06 times the stress of the nonthread post did. However, the effects of post design on the dentin were minor compared with the bite force directions. In the same post design, the maximum Von Misses stress in dentin with 45 degree oblique force was about 2.1 times with vertical force. Therefore, reducing oblique force is the main method to prevent root fracture in clinic.
Collapse
|
718
|
Yu J, Sun L, Zhou L, Luo X, Guo J, Liu C, Cong P. [Chemical constituents of fructus Amomi]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1997; 22:231-2, 255. [PMID: 10743216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Seven compounds have been isolated from Fructus Amomi. They were identified as bornyl acetate, camphor, borneol, beta-sitosterol, vanillic acid, stearic acid and palmitic acid. The vanillic acid was found in this medicine for the first time. Fifty-seven components were identified from the volatile oil of Fructus Amomi on the basis of GC-MS analysis. Eight components in the volatile oil over 1% in content are bornyl acetate, camphor, borneol, limonene, camphene, myrecene, carene-3 and alpha-terpeneol.
Collapse
|
719
|
Frazee JG, Luo X, Shiroishi MS, Luan G. A pilot study on the ability of retrograde transvenous neuroperfusion to rescue baboon brain with severe ischemia. J Stroke Cerebrovasc Dis 1997; 6:210-6. [PMID: 17894999 DOI: 10.1016/s1052-3057(97)80013-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
720
|
Thompson J, Zamboni WC, Cheshire PJ, Richmond L, Luo X, Houghton JA, Stewart CF, Houghton PJ. Efficacy of oral irinotecan against neuroblastoma xenografts. Anticancer Drugs 1997; 8:313-22. [PMID: 9180383 DOI: 10.1097/00001813-199704000-00002] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The efficacy of the topoisomerase I inhibitor, 7-ethyl-10-(4-[1-piperidino]-1-piperidino)-carbonyloxy-camptotheci n (irinotecan, CPT-11), administered by oral gavage has been examined against a panel of six independently derived neuroblastoma xenografts. Irinotecan was administered either daily for 5 days on 12 consecutive weeks ¿(d x 5)12¿ or for 5 days on two consecutive weeks repeated every 21 days for 4 cycles ¿[(d x 5)2]4¿. Given on the (d x 5)12 schedule the maximum tolerated dose (MTD) was 50 mg/kg. For intermittent scheduling ¿[(d x 5)2]4¿, the MTD was 75 mg/kg, resulting in the same total dose being administered (3 g/kg) over the period of treatment. At the MTD for the 12 consecutive week schedule there were two of 42 toxicity related deaths, whereas intermittent scheduling at the MTD resulted in none of 42 deaths. The intermittent schedule ¿[(d x 5)2]4¿ was less toxic than therapy given (d x 5)12, as at the end of treatment mice weighed 92 +/- 4% (SD; n = 6 experiments) and 81 +/- 4% (SD; n = 6 experiments) of their body weight at the start of therapy, respectively. The latter schedule was associated with loose feces starting around week 8 of therapy, broken teeth and a high incidence of swelling of the orbital conjunctiva that developed late in the course of therapy. Given (d x 5)12, irinotecan caused complete regressions of all six neuroblastoma xenograft lines. Because mice tolerate significantly greater systemic exposure to SN-38 lactone than do patients (as determined by plasma AUC at the respective MTD), we evaluated the intermittent schedule of administration, reducing the dose/administration to determine the lowest dose levels that produced objective regressions of these neuroblastoma xenografts and determined the daily systemic exposure associated with these dose levels. In four lines examined objective responses were obtained at dose levels of 12.5 or 6.25 mg/kg. The daily plasma AUC exposures associated with minimum dose achieving response in NB1691 (12.5 mg/kg), NB1643 (6.25 mg/kg) and NBEB (12.5 mg/kg) for irinotecan lactone were 219, 152 and 653 ng-h/ml, respectively; and for SN-38 lactone were 704, 418 and 987 ng-h/ml, respectively. These results indicate that childhood neuroblastoma xenografts are highly sensitive to irinotecan given by oral administration and therapeutic activity is similar to i.v. irinotecan administered on similar schedules.
Collapse
|
721
|
Côté GP, Luo X, Murphy MB, Egelhoff TT. Mapping of the novel protein kinase catalytic domain of Dictyostelium myosin II heavy chain kinase A. J Biol Chem 1997; 272:6846-9. [PMID: 9054368 DOI: 10.1074/jbc.272.11.6846] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Myosin heavy chain kinase A (MHCK A) in Dictyostelium was identified as a biochemical activity that phosphorylates threonine residues in the myosin II tail domain and regulates myosin filament assembly. The catalytic domain of MHCK A has now been mapped through the functional characterization of a series of MHCK A truncation mutants expressed in Escherichia coli. A recombinant protein comprising the central nonrepetitive domain of MHCK A (residues 552-841) was isolated in a soluble form and shown to phosphorylate Dictyostelium myosin II, myelin basic protein, and a synthetic peptide substrate. The functionally mapped catalytic domain of MHCK A shows no detectable sequence similarity to known classes of eukaryotic protein kinases but shares substantial sequence similarity with a transcribed Caenorhabditis elegans gene and with the mammalian elongation factor-2 kinase (calcium/calmodulin-dependent protein kinase III). We suggest that MHCK A represents the prototype for a novel, widely occurring protein kinase family.
Collapse
|
722
|
Luo X, Qin Y. [Advance in the study of post-wound effects of arginine]. ZHONGGUO XIU FU CHONG JIAN WAI KE ZA ZHI = ZHONGGUO XIUFU CHONGJIAN WAIKE ZAZHI = CHINESE JOURNAL OF REPARATIVE AND RECONSTRUCTIVE SURGERY 1997; 11:124-6. [PMID: 9867974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
|
723
|
Wang J, Luo X, Ji R, Zhang D. [A monoclonal antibody-based indirect competitive inhibition enzyme-linked immunosorbent assay for detecting tetrodotoxin in puffer fish]. WEI SHENG YAN JIU = JOURNAL OF HYGIENE RESEARCH 1997; 26:106-9. [PMID: 10325613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
The homogenized tissue samples of puffer fish were extracted with boiling 0.1% acetic acid solution for 2 times, then the combined filtrate was defatted with ether ethyl for 2 times and the water phase were diluted with 0.05 mol/L PBS for ELISA determination (adjusted pH to 6.5-7.0). The results showed that the minimum detecable concentration of tetrodotoxin was 1.0 x 10(-3) mg/L (0.1 ng/assay), and the standard curve was linear between 1.0 x 10(-2) and 1.0 mg/L. The recovery rates from tetrodotoxin spiked samples of this method were 73.8%-117.4%. The accuracy of ELISA was compared with the traditional mouse bioassay system. The results showed no significant differences between the two methods (for paired-t test, P > 0.2), and significant correlations in tetrodotoxin concentration were obtained (r = 0.916).
Collapse
|
724
|
Tang C, Zhang C, He Z, Tang Z, Hong J, Luo X, Wu Z. [Pharmacological study of cholagogic capsule]. ZHONG YAO CAI = ZHONGYAOCAI = JOURNAL OF CHINESE MEDICINAL MATERIALS 1997; 20:149-52. [PMID: 12572446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Cholagogic capsule is mainly composed of Fiuctus Cardui, Mariae, Oleum Menthae Piperilae, Radix Currmae, olia taraxaci, Oleum Hyperici. It is shown that Cholagogic Capsule increase the rat's bile secretion significantly, but bile component is not influenced effectively, the retention jaundice models of which are created by ANIT isn't influenced effectively. It can reduce the mouse pinna swelling caused by dimethythenzene and depress the metatarsal swelling induced by carragenin, the antiinflammatory effect keeps for more than 4 h. It inhibits the contraction of gallbladder smooth musele of Guinea Pig caused by Ach. The results show that cholagogic Capsule increase bile secretion, antispasmodic and antiinflammatory effect. It is suggested the therapeutic effects of Cholagogic Capsule in sand-like calcul and acute chronic cholecystitis are related to the above pharmaological effects.
Collapse
|
725
|
Thompson J, Zamboni WC, Cheshire PJ, Lutz L, Luo X, Li Y, Houghton JA, Stewart CF, Houghton PJ. Efficacy of systemic administration of irinotecan against neuroblastoma xenografts. Clin Cancer Res 1997; 3:423-31. [PMID: 9815701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The efficacy of the topoisomerase I inhibitor 7-ethyl-10-(4-[1-piperidino]-1-piperidino)-carbonyloxy-camptotheci n (irinotecan, CPT-11) has been examined against a panel of six independently derived neuroblastoma xenografts. Intensive courses of therapy, where irinotecan was administered i.v. daily 5 days per week for two consecutive weeks [(dx5)2; defined as 1 cycle], were compared to more protracted low-dose schedules where cycles were repeated every 21 days for a total of three courses ¿abbreviated [(dx5)2]3¿. When administered (dx5)2 for a single cycle, the maximum tolerated daily dose was 40 mg/kg. Irinotecan induced a high frequency of complete regressions (CRs) in four of the six lines examined; however, most tumors achieving CR regrew during the period of observation (12 weeks). Furthermore, there was no advantage in high-dose regimens as compared to low dose (10 mg/kg) on the same schedule. Protracted schedules of administration, where three courses of therapy were given at 21-day intervals ¿[(dx5)2]3¿ i.v. were examined at 10 and 5 mg/kg/dose. Even at the lower dose level, irinotecan caused 100% CR in all tumor lines that were maintained at 12 weeks. To determine the minimum dose levels required to induce objective regressions of neuroblastoma xenografts, decreasing doses were examined using the [(dx5)2]3 i.v. schedule. At 2.5 mg/kg/dose, >90% of NB-1643, NB-1691, NB-1382.2, and NB-EB xenografts demonstrated CR, whereas at 1.25 mg/kg/dose, all six tumor lines evaluated demonstrated objective regressions (>/=50% volume reduction), with a high frequency of CRs in four tumor lines. The 10-hydroxy-7-ethyl CPT lactone single-day systemic exposure measured with the minimum dose (2.5 mg/kg) associated with complete response was 198, 257, and 228 ng.h/ml for mice bearing NB-1643, NB-1691, and NB-EB tumors, respectively. These results indicate that childhood neuroblastoma xenografts are highly sensitive to irinotecan given by parenteral administration, and that efficacy is schedule dependent.
Collapse
|