51
|
Barker FG, Simmons ML, Chang SM, Prados MD, Larson DA, Sneed PK, Wara WM, Berger MS, Chen P, Israel MA, Aldape KD. EGFR overexpression and radiation response in glioblastoma multiforme. Int J Radiat Oncol Biol Phys 2001; 51:410-8. [PMID: 11567815 DOI: 10.1016/s0360-3016(01)01609-1] [Citation(s) in RCA: 165] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE Recent studies have suggested relative radioresistance in glioblastoma multiforme (GM) tumors in older patients, consistent with their shorter survival. Two common molecular genetic abnormalities in GM are age related: epidermal growth factor receptor (EGFR) overexpression in older patients and p53 mutations in younger patients. We tested whether these abnormalities correlated with clinical heterogeneity in GM response to radiation treatment. METHODS AND MATERIALS Radiographically assessed radiation response (5-level scale) was correlated with EGFR immunoreactivity, p53 immunoreactivity, and p53 exon 5-8 mutation status in 170 GM patients treated using 2 prospective clinical protocols. Spearman rank correlation and proportional-odds ordinal regression were used for univariate and multivariate analysis. RESULTS Positive EGFR immunoreactivity predicted poor radiographically assessed radiation response (p = 0.046). Thirty-three percent of tumors with no EGFR immunoreactivity had good radiation responses (>50% reduction in tumor size by CT or MRI), compared to 18% of tumors with intermediate EGFR staining and 9% of tumors with strong staining. There was no significant relationship between p53 immunoreactivity or mutation status and radiation response. Significant relationships were noted between EGFR score and older age and between p53 score or mutation status and younger age. CONCLUSION The observed relative radioresistance of some GMs is associated with overexpression of EGFR.
Collapse
|
52
|
Doong RA, Chen CH, Maithreepala RA, Chang SM. The influence of pH and cadmium sulfide on the photocatalytic degradation of 2-chlorophenol in titanium dioxide suspensions. WATER RESEARCH 2001; 35:2873-2880. [PMID: 11471687 DOI: 10.1016/s0043-1354(00)00580-7] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The influence of pH and cadmium sulfide on the photocatalytic degradation of 2-chlorophenol (2-CP) in titanium dioxide suspensions was investigated to evaluate the feasibility of mixed semiconductors on the photodegradation of chlorinated organics in aqueous solution. Apparent first-order rate constants (k(obs)) and initial rate constants were used to evaluate the degradation efficiency of 2-CP. Higher degradation efficiency of 2-CP was observed at higher pH values. The apparent pseudo-first-order rate constant was 0.036 min(-1) at pH 12.5 in TiO2/UV system, while a 2- to 9-fold decrease in k(obs) was observed over the pH range of 2.5-9.5. The addition of phosphate buffer solutions at different pH values have different effects on the degradation of 2-CP. H2PO4- has little effect on the photodegradation of 2-CP, while HPO4(2-) could inhibit the photodegradation efficiency of 2-CP. Chlorocatechol, hydroquinone, benzoquinone and phenol were identified as the predominant aromatic intermediates for the photocatalytic degradation of 2-CP. Moreover, less aromatic intermediates at higher pH were observed. Direct oxidation contributed significantly to the photodegradation of 2-CP. An addition of a semiconductor decreased the initial and apparent first-order rate constants of 2-CP. The cutoff of wavelength of 320nm could diminish the contribution of direct photolysis of 2-CP. The combination of cadmium sulfide and titanium dioxide can lead to an enhanced rate of disappearance of 2-CP compared to those in single semiconductor system. A 1.2 to 2.5-fold increase in rate constant in coupled semiconductor system relative to the single semiconductor system was obtained.
Collapse
|
53
|
Wu WC, Chang SM, Chen JY, Chang CW. Management of postvitrectomy diabetic vitreous hemorrhage with tissue plasminogen activator (t-PA) and volume homeostatic fluid-fluid exchanger. J Ocul Pharmacol Ther 2001; 17:363-71. [PMID: 11572467 DOI: 10.1089/108076801753162771] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The incidence of recurrent vitreous hemorrhage of proliferative diabetic retinopathy following posterior vitrectomy ranges from 29% to 75% in reported series. Fluid-gas exchange and vitreous cavity lavage are the popular methods of treating this kind of recurrent hemorrhage. The fluid-gas exchange cannot offer clear vision immediately after the procedure. To improve the function of the classic vitreous cavity lavage, we designed a volume homeostatic fluid-fluid exchanger - Chen's I/A device. Tissue plasminogen activator (t-PA) is a protease that preferentially converts fibrin-bound plasminogen to the active proteolytic enzyme, plasmin. It has been clinically and experimentally proven effective in lysis of postvitrectomy blood clot and fibrin formation. When the blood clot is formed in the vitreous cavity, intravitreal injection of t-PA can convert plasminogen to plasmin and remove the clot. From July 1999 to January 2000, ten eyes of postvitrectomy diabetic vitreous hemorrhage (PDVH) were collected. In each case, 4 days after intravitreal injection (IVI) of t-PA (30 microg), vitreous cavity lavage was performed with Chen's I/A device. Of these cases, 8 eyes (80%) experienced an immediate clearing of the vitreous cavity. Early complications included anterior hyaloid fibrovascular proliferation (2 eyes) and postoperative intraocular pressure elevation (3 eyes). On the basis of the results of this study, our conclusion is that volume homeostatic vitreous cavity lavage, combined with intravitreal injection of t-PA, is an excellent method for treatment of postvitrectomy diabetic vitreous hemorrhage but, in cases of PDVH with iris rubeosis, the advantage of this procedure is uncertain.
Collapse
|
54
|
Dowling C, Bollen AW, Noworolski SM, McDermott MW, Barbaro NM, Day MR, Henry RG, Chang SM, Dillon WP, Nelson SJ, Vigneron DB. Preoperative proton MR spectroscopic imaging of brain tumors: correlation with histopathologic analysis of resection specimens. AJNR Am J Neuroradiol 2001; 22:604-12. [PMID: 11290466 PMCID: PMC7976037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
BACKGROUND AND PURPOSE Tumor progression is often difficult to distinguish from nonneoplastic treatment response on the basis of MR images alone. This study correlates metabolite levels measured by preoperative MR spectroscopic (MRS) imaging with histologic findings of biopsies, obtained during image-guided resections of brain mass lesions, to clarify the potential role of MRS in making this distinction. METHODS Twenty-nine patients with brain tumors underwent high-resolution (0.2-1 cc) 3D proton MRS imaging and MR imaging before undergoing surgery; 11 had a newly diagnosed neoplasm, and 18 had recurrent disease. Surgical biopsies were obtained from locations referenced on MR images by guidance with a surgical navigation system. MR spectral voxels were retrospectively centered on each of 79 biopsy locations, and metabolite levels were correlated with histologic examination of each specimen. RESULTS All mass lesions studied, whether attributable to tumor or noncancerous effects of previous therapy, showed abnormal MR spectra compared with normal parenchyma. When the pattern of MRS metabolites consisted of abnormally increased choline and decreased N-acetyl aspartate (NAA) resonances, histologic findings of the biopsy specimen invariably was positive for tumor. When choline and NAA resonances were below the normal range, histologic findings were variable, ranging from radiation necrosis, astrogliosis, and macrophage infiltration to mixed tissues that contained some low-, intermediate-, and high-grade tumor. CONCLUSION This study demonstrated that 3D MRS imaging can identify regions of viable cancer, which may be valuable for guiding surgical biopsies and focal therapy. Regions manifesting abnormal MR spectra had a mixture of histologic findings, including astrogliosis, necrosis, and neoplasm.
Collapse
|
55
|
Chang SM, Kuhn JG, Robins HI, Schold SC, Spence AM, Berger MS, Mehta M, Pollack IF, Rankin C, Prados MD. A Phase II study of paclitaxel in patients with recurrent malignant glioma using different doses depending upon the concomitant use of anticonvulsants: a North American Brain Tumor Consortium report. Cancer 2001. [PMID: 11180089 DOI: 10.1002/1097-0142(20010115)91:2<417::aid-cncr1016>3.0.co;2-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND The primary objective of the current study was to determine the response rate of paclitaxel in patients with recurrent malignant glioma by using different doses dependent on the concomitant use of anticonvulsants. Secondary objectives were to determine the time period to treatment failure, to evaluate toxicities, and to obtain pharmacokinetic data. METHODS Adult patients who had recurrent malignant glioma were treated with paclitaxel. Patients were treated at different doses depending on the concomitant use of anticonvulsants known to induce the p450 hepatic enzyme system. Patients on such agents were treated at a dose of 330 mg/m2, whereas those not on these anticonvulsants were treated at a dose of 210 mg/m2. Tumor response was assessed at 6-week intervals. Treatment was continued until documented tumor progression or unacceptable toxicity occurred, or a total of 12 paclitaxel infusions was completed. RESULTS From January 1997 to June 1997, 23 patients were treated with paclitaxel. Four patients were ineligible for the current study. Of the 19 eligible patients, there were no responses seen. Four (21%) had stabilization of disease. Median time to treatment failure was 1 month (95% confidence interval [CI], 1-2 mos) and median survival was 7 months (95% CI, 6-10 mos). Three patients were removed from the current study because they had toxicity. Pharmacokinetic studies demonstrated that drug levels and clearance values were consistent with previously reported findings. CONCLUSION Even though higher doses were administered to patients who had recurrent malignant glioma and who were on concomitant anticonvulsants, there were no objective responses to paclitaxel. Time to tumor progression was 1 month. Further testing of paclitaxel at this dose schedule does not appear to be warranted in this patient population.
Collapse
|
56
|
Chang SM, Kuhn JG, Robins HI, Schold SC, Spence AM, Berger MS, Mehta M, Pollack IF, Rankin C, Prados MD. A Phase II study of paclitaxel in patients with recurrent malignant glioma using different doses depending upon the concomitant use of anticonvulsants: a North American Brain Tumor Consortium report. Cancer 2001; 91:417-22. [PMID: 11180089 DOI: 10.1002/1097-0142(20010115)91:2<417::aid-cncr1016>3.0.co;2-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND The primary objective of the current study was to determine the response rate of paclitaxel in patients with recurrent malignant glioma by using different doses dependent on the concomitant use of anticonvulsants. Secondary objectives were to determine the time period to treatment failure, to evaluate toxicities, and to obtain pharmacokinetic data. METHODS Adult patients who had recurrent malignant glioma were treated with paclitaxel. Patients were treated at different doses depending on the concomitant use of anticonvulsants known to induce the p450 hepatic enzyme system. Patients on such agents were treated at a dose of 330 mg/m2, whereas those not on these anticonvulsants were treated at a dose of 210 mg/m2. Tumor response was assessed at 6-week intervals. Treatment was continued until documented tumor progression or unacceptable toxicity occurred, or a total of 12 paclitaxel infusions was completed. RESULTS From January 1997 to June 1997, 23 patients were treated with paclitaxel. Four patients were ineligible for the current study. Of the 19 eligible patients, there were no responses seen. Four (21%) had stabilization of disease. Median time to treatment failure was 1 month (95% confidence interval [CI], 1-2 mos) and median survival was 7 months (95% CI, 6-10 mos). Three patients were removed from the current study because they had toxicity. Pharmacokinetic studies demonstrated that drug levels and clearance values were consistent with previously reported findings. CONCLUSION Even though higher doses were administered to patients who had recurrent malignant glioma and who were on concomitant anticonvulsants, there were no objective responses to paclitaxel. Time to tumor progression was 1 month. Further testing of paclitaxel at this dose schedule does not appear to be warranted in this patient population.
Collapse
|
57
|
Prados MD, Wara WM, Sneed PK, McDermott M, Chang SM, Rabbitt J, Page M, Malec M, Davis RL, Gutin PH, Lamborn K, Wilson CB, Phillips TL, Larson DA. Phase III trial of accelerated hyperfractionation with or without difluromethylornithine (DFMO) versus standard fractionated radiotherapy with or without DFMO for newly diagnosed patients with glioblastoma multiforme. Int J Radiat Oncol Biol Phys 2001; 49:71-7. [PMID: 11163499 DOI: 10.1016/s0360-3016(00)01458-9] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE To report the results of a prospective Phase III trial for patients with newly diagnosed glioblastoma multiforme (GBM), treated with either accelerated hyperfractionated irradiation with or without difluromethylornithine (DFMO) or standard fractionated irradiation with or without DFMO. METHODS AND MATERIALS Adult patients with newly diagnosed GBM were registered and randomized following surgery to one of 4 treatment arms: Arm A, accelerated hyperfractionation alone using 2 fractions a day of 1.6 Gy to a total dose of 70.4 Gy in 44 fractions; Arm B, accelerated hyperfractionation as above plus DFMO 1.8 gm/m2 by mouth every 8 h beginning one week before radiation until the last fraction was given; Arm C, single-fraction irradiation of 1.8 Gy/day to 59.4 Gy; Arm D, single-fraction irradiation as in Arm C plus DFMO given as in Arm B. Patients were followed for progression-free survival (PFS) and overall survival (OS), as well as for toxicity. Eligibility required histologically proven GBM, age > or =18, Karnofsky performance status (KPS) > or =60, and no prior chemotherapy or radiotherapy. Adjuvant chemotherapy was not used in this protocol. RESULTS A total of 231 eligible patients were enrolled. There were 95 men and 136 women with a median age of 57 years, and median KPS of 90. Extent of resection was total in 23, subtotal in 152, and biopsy only in 56 patients. The 4 arms were balanced with respect to age, KPS, and extent of resection. Times to event measurements are from date of diagnosis. Median OS and PFS were 40 and 19 weeks for Arm A; 42 and 22 weeks for Arm B; 37 and 16 weeks for Arm C; and 44 and 19 weeks for Arm D (p = 0.48 for survival; p = 0.32 for PFS). Comparison of the 2 arms treated with DFMO to the 2 arms without DFMO revealed no difference in OS (37 weeks vs. 42 weeks, p = 0.12) or PFS and thus no benefit to the use of DFMO. Comparison of the 2 standard fractionation arms to the 2 accelerated hyperfractionation arms also resulted in no difference in OS (42 weeks vs. 41 weeks, p = 0.75) or PFS, showing no benefit to accelerated hyperfractionated irradiation. CONCLUSION In this prospective Phase III study, no survival or PFS benefit was seen with accelerated hyperfractionated irradiation to 70.4 Gy, nor was any benefit seen with DFMO as a radiosensitizer. Standard fractionated irradiation to 59.4 Gy remains the treatment of choice for newly diagnosed patients with glioblastoma multiforme.
Collapse
|
58
|
Chang SM, Hou CL. The frequency and efficacy of differential sacral roots innervation to bladder detrusor in Asian people. Spinal Cord 2000; 38:773. [PMID: 11175380 DOI: 10.1038/sj.sc.3100998] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
59
|
Collins PL, Moore JJ, Lundgren DW, Choobineh E, Chang SM, Chang AS. Gestational changes in uterine L-type calcium channel function and expression in guinea pig. Biol Reprod 2000; 63:1262-70. [PMID: 11058528 DOI: 10.1095/biolreprod63.5.1262] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Pregnancy can influence both the resting membrane potential and the ion channel composition of the uterine myometrium. Calcium flux is essential for excitation-contraction coupling in pregnant uterus. The uterine L-type calcium channel is an important component in mediating calcium flux and is purported to play a role in parturition. This study was undertaken to characterize gestational changes in 1) the uterine contractile response to the L-type calcium channel agonist, Bay K 8644; 2) the mRNA expression of channel subunits by semiquantitative reverse transcriptase-polymerase chain reaction; and 3) estimate channel protein levels by measuring (3)H-isradipine binding at the dihydropyridine binding site of the alpha(1c) subunit utilizing saturation binding methods. Sensitivity to Bay K 8644 increases beginning at 0.8 of gestation and persists through term. The change in sensitivity is coincident with an increased mRNA expression of the alpha(1c) and beta(2) subunits but with the least detectable amounts of isradipine binding. The expressed alpha(1c) transcript represents a novel structural variant with a 118-amino acid deletion in the III-IV linker and repeats IVS1-S3 of the protein sequence. The guinea pig uterine L-type calcium channel activity is highly regulated through gestation, but the regulation of mRNA expression may be different from regulation of protein levels, estimated by isradipine binding. The up-regulation of function, alpha(1c) subunit mRNA expression, and isradipine binding at term gestation are consistent with a role for this ion channel in parturition.
Collapse
MESH Headings
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/metabolism
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology
- Amino Acid Sequence
- Animals
- Calcium Channel Agonists/pharmacology
- Calcium Channel Blockers/metabolism
- Calcium Channels, L-Type/biosynthesis
- Calcium Channels, L-Type/metabolism
- Dihydropyridines/metabolism
- Female
- Guinea Pigs
- Isradipine/metabolism
- Molecular Sequence Data
- Pregnancy
- Pregnancy, Animal/metabolism
- RNA, Messenger/biosynthesis
- Rabbits
- Rats
- Reverse Transcriptase Polymerase Chain Reaction
- Time Factors
- Uterine Contraction/drug effects
- Uterus/metabolism
Collapse
|
60
|
Evans ME, Jordan CT, Chang SM, Conrad C, Gerberding JL, Kaufman HL, Mayhall CG, Nolta JA, Pilaro AM, Sullivan S, Weber DJ, Wivel NA. Clinical infection control in gene therapy: a multidisciplinary conference. Infect Control Hosp Epidemiol 2000; 21:659-73. [PMID: 11083185 DOI: 10.1086/501711] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Gene therapy is being studied for the treatment of a variety of acquired and inherited disorders. Retroviruses, adenoviruses, poxviruses, adeno-associated viruses, herpesviruses, and others are being engineered to transfer genes into humans. Treatment protocols using recombinant viruses are being introduced into clinical settings. Infection control professionals will be involved in reviewing the safety of these agents in their clinics and hospitals. To date, only a limited number of articles have been written on infection control in gene therapy, and no widely available recommendations exist from federal or private organizations to guide infection control professionals. The goals of the conference were to provide a forum where gene therapy experts could share their perspectives and experience with infection control in gene therapy and to provide an opportunity for newcomers to the field to learn about issues specific to infection control in gene therapy. Recommendations for infection control in gene therapy were proposed.
Collapse
|
61
|
Levin VA, Uhm JH, Jaeckle KA, Choucair A, Flynn PJ, Prados MD, Bruner JM, Chang SM, Kyritsis AP, Gleason MJ, Hess KR. Phase III randomized study of postradiotherapy chemotherapy with alpha-difluoromethylornithine-procarbazine, N-(2-chloroethyl)-N'-cyclohexyl-N-nitrosurea, vincristine (DFMO-PCV) versus PCV for glioblastoma multiforme. Clin Cancer Res 2000; 6:3878-84. [PMID: 11051233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Although the efficacy of the nitrosourea-based combination chemotherapy procarbazine, N-(2-chloroethyl)-N'-cyclohexyl-N-nitrosurea, and vincristine (PCV) has been previously demonstrated in the setting of anaplastic/intermediate-grade gliomas, the benefit for glioblastoma patients remains unproven. In the current study, we sought to determine whether the addition of alpha-difluoromethylornithine (eflornithine), an inhibitor of ornithine decarboxylase, which has shown encouraging results in the setting of recurrent glioma patients, to a nitrosourea-based therapy (PCV) would constitute a more effective adjuvant therapy in the treatment of glioblastoma multiforme patients in the postradiation therapy setting. Following conventional radiation therapy, 272 glioblastoma (GBM) patients were randomized to receive either alpha-difluoromethylornithine-PCV (DFMO-PCV; 134 patients) or PCV alone (138 patients), with survival and time to tumor progression being the primary endpoints. The starting dosage of DFMO was 3.0 g/m2 p.o. q8h for 14 days before and after treatment with N-(2-chloroethyl)-N-cyclohexyl-N-nitrosurea; PCV was administered as previously described1. Clinical and radiological (Gadolinium-enhanced MRI) follow-ups were nominally at the end of each 6 or 8 week cycle (PCV at 6 weeks; DFMO-PCV at 8 weeks). Laboratory evaluations for hematologic and other adverse effects were at 2 week intervals. There was no difference in median survival or median time-to-tumor progression between the two treatment groups, as measured from day of commencement of postradiotherapy chemotherapy [MS (months): DFMO-PCV, 10.5; Overall survival, as measured from time of tumor diagnosis at first surgery, was 13.3 and 14.2 months at the median and 6.2 and 8.7% at 5 years, respectively, for the DFMO-PCV and PCV arms. The treatment effect was unchanged after adjustment for age, performance status (KPS), extent of surgery, and other factors using the multivariate Cox proportional hazard model. Adverse effects associated with DFMO consisted of gastrointestinal (diarrhea nausea/vomiting), cytopenias, and minimal ototoxicity (limited to tinnitus) at the dose range tested. The addition of DFMO to the nitrosourea-based PCV regimen in this phase III study demonstrated no additional benefit in glioblastoma patients, underscoring the resistance of glioblastoma multiforme tumors to alkylating agents. For patients with anaplastic (intermediate grade) gliomas, in which the previously demonstrated benefit of post-radiation chemotherapy is more substantial, the evaluation of DFMO-PCV vs. PCV is still ongoing and hopefully will yield more encouraging results.
Collapse
|
62
|
Sheridan PL, Bodner M, Lynn A, Phuong TK, DePolo NJ, de la Vega DJ, O'Dea J, Nguyen K, McCormack JE, Driver DA, Townsend K, Ibañez CE, Sajjadi NC, Greengard JS, Moore MD, Respess J, Chang SM, Dubensky TW, Jolly DJ, Sauter SL. Generation of retroviral packaging and producer cell lines for large-scale vector production and clinical application: improved safety and high titer. Mol Ther 2000; 2:262-75. [PMID: 10985957 DOI: 10.1006/mthe.2000.0123] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
For many applications, human clinical therapies using retroviral vectors still require many technological improvements in key areas of vector design and production. These improvements include higher unprocessed manufacturing titers, complement-resistant vectors, and minimized potential to generate replication-competent retrovirus (RCR). To address these issues, we have developed a panel of human packaging cell lines (PCLs) with reduced homology between retroviral vector and packaging components. These reduced-homology PCLs allowed for the use of a novel high multiplicity of transduction ("high m.o. t.") method to introduce multiple copies of provector within vector-producing cell lines (VPCLs), resulting in high-titer vector without the generation of RCR. In a distinct approach to increase vector yields, we integrated manufacturing parameters into screening strategies and clone selection for large-scale vector production. Collectively, these improvements have resulted in the development of diverse VPCLs with unprocessed titers exceeding 2 x 10(7) CFU/ml. Using this technology, human Factor VIII VPCLs yielding titers as high as 2 x 10(8) CFU/ml unprocessed supernatant were generated. These cell lines produce complement-resistant vector particles (N. J. DePolo et al., J. Virol. 73: 6708-6714, 1999) and provide the basis for an ongoing Factor VIII gene therapy clinical trial.
Collapse
|
63
|
Chang SM, Hou CL. The development of the distally based radial forearm flap in hand reconstruction with preservation of the radial artery. Plast Reconstr Surg 2000; 106:955-7. [PMID: 11007425 DOI: 10.1097/00006534-200009040-00055] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
64
|
Chang SM, Hou CL, Dong DQ, Zhang H. Urologic status of 74 spinal cord injury patients from the 1976 Tangshan earthquake, and managed for over 20 years using the Credé maneuver. Spinal Cord 2000; 38:552-4. [PMID: 11035477 DOI: 10.1038/sj.sc.3101060] [Citation(s) in RCA: 32] [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
OBJECTIVE To evaluate the urologic safety of long-term Credé maneuver as bladder management in spinal cord injured patients. METHODS Seventy-four paraplegics were included in this cross-sectional study. They were injured in the Tangshan earthquake in 1976. All patients have large volume (flaccid) bladders and have practiced the Credé maneuver for more than 20 years to expel urine. Current residual urine volume and urologic complications were investigated. RESULTS 93.2% of patients have residual urine larger than 100 ml and 50% of cases larger than 300 ml. The prevalence of urologic complications is high: pyuria in 82.4%, urinary lithiasis in 31.3%, ureteral dilatation in 59.5%, hydronephrosis in 35.1% and renal damage in 16.2%. Men are more susceptible to upper urinary tract deterioration than women (P<0.05). CONCLUSION The Credé maneuver is not safe for long-term use in spinal cord injury patients, especially in men.
Collapse
|
65
|
Chang SM, Hou CL, Liu DX. Distally based superficial peroneal neuroadipofascial turnover flap for dorsal foot reconstruction. Ann Plast Surg 2000; 45:101-2. [PMID: 10917109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
|
66
|
Chang SM, Hou CL. Role of large superficial veins in distally based flaps of the extremities. Plast Reconstr Surg 2000; 106:230-1. [PMID: 10883652 DOI: 10.1097/00006534-200007000-00060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
67
|
Thalmann GN, Sikes RA, Wu TT, Degeorges A, Chang SM, Ozen M, Pathak S, Chung LW. LNCaP progression model of human prostate cancer: androgen-independence and osseous metastasis. Prostate 2000; 44:91-103 Jul 1;44(2). [PMID: 10881018 DOI: 10.1002/1097-0045(20000701)44:2<91::aid-pros1>3.0.co;2-l] [Citation(s) in RCA: 285] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Clinically, the lethal phenotypes of human prostate cancer are characterized by their progression to androgen-independence and their propensity to form osseous metastases. We reported previously on the establishment of androgen-independent (AI) human prostate cancer cell lines derived from androgen-dependent (AD) LNCaP cells, with androgen independence defined as the capability of prostate cancer cells to grow in castrated hosts. One of the sublines, C4-2, was found to be AI, highly tumorigenic, and metastatic, having a proclivity for metastasis to the bone. METHODS We established the AI and bone metastatic cell sublines B2, B3, B4, and B5 from the parental C4-2 subline, using a previously established coinoculating procedure. We determined the biologic behavior of the parental and derivative LNCaP sublines in vivo and in vitro, as well as their molecular and cytogenetic characteristics. RESULTS Unlike other human prostate cancer models, the LNCaP progression model shares remarkable similarities with human prostate cancer. We observed a comparable pattern of metastasis from the primary to the lymph node and to the axial skeleton, with a predominant phenotype of osteoblastic reaction; 25-37.5% of the animals developed paraplegia. Cytogenetic and biochemical characterizations of LNCaP sublines also indicate close similarities between human prostate cancer and the LNCaP progression model. Additional chromosomal changes were detected in B2-B5 sublines derived from C4-2 bone metastases. These LNCaP sublines were found to grow faster under anchorage-dependent but not -independent conditions. The in vitro invasion and in vivo metastatic potential of these LNCaP sublines surprisingly correlated with anchorage-dependent and not -independent growth. The derivative LNCaP sublines when cultured in vitro produced a substantially higher (20-30-fold) amount of basal steady-state concentrations of PSA than that of the parental LNCaP cells. PSA production was high initially, but was markedly reduced when the derivative cell lines were inoculated and allowed to grow long-term in vivo for the establishment of tumors and metastasis, suggesting that unknown host factors derived either from the prostate or the bone can effectively downregulate PSA expression by prostate tumor epithelium. CONCLUSIONS The LNCaP model of human prostate cancer progression will help improve our understanding of the mechanisms of androgen-independence and osseous metastasis, and tumor-host determinants of PSA expression.
Collapse
|
68
|
Walker SP, Grantham-Mcgregor SM, Powell CA, Chang SM. Effects of growth restriction in early childhood on growth, IQ, and cognition at age 11 to 12 years and the benefits of nutritional supplementation and psychosocial stimulation. J Pediatr 2000; 137:36-41. [PMID: 10891819 DOI: 10.1067/mpd.2000.106227] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVES (1) To determine whether benefits to growth and cognition remain after intervention in growth-restricted children who received psychosocial stimulation and nutritional supplementation in early childhood. (2) To investigate the extent of the differences in IQ and cognition at age 11 to 12 years between growth-restricted and non-growth-restricted children. STUDY DESIGN Growth-restricted and non-growth-restricted children were identified at age 9 to 24 months, at which time the growth-restricted children participated in a 2-year randomized trial of nutritional supplementation and psychosocial stimulation. Eight years after the interventions ended, the children's growth, IQ, and cognitive functions were measured. RESULTS There were no significant benefits from supplementation to growth or cognition. Children who had received stimulation had higher scores on the Weschler Intelligence Scales for Children-Revised full-scale (IQ) and verbal scale and tests of vocabulary and reasoning (all P <.05). The growth-restricted children had significantly lower scores than the non-growth-restricted children on 10 of 11 cognitive tests. CONCLUSIONS Psychosocial stimulation had small but significant long-term benefits on cognition in growth-restricted children. Growth-restricted children had significantly poorer performance than non-growth-restricted children on a wide range of cognitive tests, supporting the conclusion that growth restriction has long-term functional consequences.
Collapse
|
69
|
Doong RA, Chang SM. Relationship between electron donor and microorganism on the dechlorination of carbon tetrachloride by an anaerobic enrichment culture. CHEMOSPHERE 2000; 40:1427-1433. [PMID: 10789984 DOI: 10.1016/s0045-6535(99)00319-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
An investigation involving the supplement of different concentrations of substrates and microorganisms was carried out under anaerobic condition to assess the feasibility of bioremediation of carbon tetrachloride (CCl4) with the amendment of low concentrations of auxiliary substrate and microorganisms. The concentrations of substrate and microorganisms ranged from 10 to 100 mg/l and from 3.7 x 10(4) to 3.7 x 10(6) cell/ml, respectively. The biotransformation rate of CCl4 increased progressively with the increase in the concentrations of the substrate and microorganisms. In the low biomass-amended system (3.7 x 10(4) cells/ml), 28-71% and 57-96% of CCl4 removals were exhibited when 10-100 mg/l of acetate or glucose was supplemented, respectively, whereas nearly complete degradation of CCl4 was observed in the heavily inoculated systems (3.7 x 10(6) cells/ml). An addition of electron donor in the low microbial activity batches enhanced greater efficiency in dechlorination than in the high microbial activity batches. The second-order rate constants ranged from 0.0059 to 0.0092 l/mg/day in high biomass input system, while a two- to four-fold increase in rate constant was obtained in the low microbial activity system. This study indicates that biomass was the more important environmental parameter than substrate affecting the fate of CCl4. The addition of auxiliary substrates was effective only in low biomass-amended batches (0.56 mg-VSS/l) and diminished inversely with the increase of microbial concentration.
Collapse
|
70
|
Doong RA, Chang SM, Sun YC. Solid-phase microextraction for determining the distribution of sixteen US Environmental Protection Agency polycyclic aromatic hydrocarbons in water samples. J Chromatogr A 2000; 879:177-88. [PMID: 10893034 DOI: 10.1016/s0021-9673(00)00347-2] [Citation(s) in RCA: 223] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A solid-phase microextraction (SPME) procedure has been developed for the determination of 16 US Environmental Protection Agency promulgated polycyclic aromatic hydrocarbons (PAHs). Five kinds of SPME fibers were used and compared in this study. The extracted sample was analyzed by gas chromatography with flame ionization detection or mass spectrometry. Parameters affecting the sorption of analyte into the fibers, including sampling time, thickness of the fiber coating, and the effect of temperature, have been examined. Moreover, the feasibility of headspace SPME with different working temperatures was evaluated. The method was also applied to real samples. The 85-microm polyacrylate (PA) and 100-microm poly(dimethylsiloxane) (PDMS) fibers were shown to have the highest affinities for the selected PAHs. The PA fiber was more suitable than the PDMS fiber for the determination of low-ring PAHs while high sensitivity of high-ring PAHs was observed when a 100-microm PDMS fiber was used. The method showed good linearity between 0.1 and 100 ng/ml with regression coefficients ranging from 0.94 to 0.999. The reproducibility of the measurements between fibers was found to be very good. The precisions of PA and PDMS fibers were from 3 to 24% and from 3 to 14%, respectively. Headspace SPME is a valid alternative for the determination of two- to five-ring PAHs. A working temperature of 60 degrees C provides significant enhancement in sensitivity of two- to five-ring PAHs having low vapor pressures (>10(-6) mmHg at 25 degrees C) (1 mmHg = 133.3 Pa) and low Henry's constants (>10 atm ml/mol) (1 atm = 1.01 x 10(5) Pa).
Collapse
|
71
|
Henry RG, Vigneron DB, Fischbein NJ, Grant PE, Day MR, Noworolski SM, Star-Lack JM, Wald LL, Dillon WP, Chang SM, Nelson SJ. Comparison of relative cerebral blood volume and proton spectroscopy in patients with treated gliomas. AJNR Am J Neuroradiol 2000; 21:357-66. [PMID: 10696024 PMCID: PMC7975338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
BACKGROUND AND PURPOSE Elevated relative regional cerebral blood volume (rCBV) reflects the increased microvascularity that is associated with brain tumors. The purpose of this study was to investigate the potential role of rCBV in the determination of recurrent/residual disease in patients with treated gliomas. METHODS Thirty-one rCBV studies were performed in 19 patients with treated gliomas. All patients also had proton MR spectroscopy and conventional MR imaging. Regions of abnormality were identified on conventional MR images by two neuroradiologists and compared with rCBV and MR spectroscopic data. Metabolites and rCBV were quantified and compared in abnormal regions. RESULTS In high-grade tumors, rCBV values were proportional to choline in regions of tumor and nonviable tissue. Although the presence of residual/recurrent disease was often ambiguous on conventional MR images, the rCBV maps indicated regions of elevated vascularity in all low-grade tumors and in 12 of 17 grade IV lesions. Regions of elevated and low rCBV corresponded well with spectra, indicating tumor and nonviable tissue, respectively. CONCLUSION This study suggests that rCBV maps and MR spectroscopy are complementary techniques that may improve the detection of residual/recurrent tumor in patients with treated gliomas. Compared with the spectra, the rCBV maps may better reflect the heterogeneity of the tumor regions because of their higher resolution. The multiple markers of MR spectroscopy enable better discrimination between normal and abnormal tissue than do the rCBV maps.
Collapse
|
72
|
Schold SC, Kuhn JG, Chang SM, Bosik ME, Robins HI, Mehta MP, Spence AM, Fulton D, Fink KL, Prados MD. A phase I trial of 1,3-bis(2-chloroethyl)-1-nitrosourea plus temozolomide: a North American Brain Tumor Consortium study. Neuro Oncol 2000; 2:34-9. [PMID: 11302252 PMCID: PMC1920698 DOI: 10.1093/neuonc/2.1.34] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The North American Brain Tumor Consortium conducted a phase I trial of the combination 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and temozolomide. Eligibility included a patient with a cancer type that was considered refractory to standard therapy. Prior nitrosourea treatments were not permitted. There were parallel dose escalations in two treatment schedules. Forty-five patients were enrolled during an 18-month period. The maximum tolerated doses (MTDs) when temozolomide followed BCNU (Arm A) were temozolomide at 550 mg/m2/p.o. and BCNU at 150 mg/m2/i.v.), whereas the MTD when temozolomide preceded BCNU (Arm B) was temozolomide at 400 mg/m2/p.o. and BCNU at 100 mg/m2/i.v. Toxicity was predominantly hematologic, although there were three instances of pulmonary toxicity, which in one case could have represented potentiation of nitrosourea-induced pulmonary fibrosis. The half-life of temozolomide was 1.86 (+/-0.31) h. There was a moderate relationship between dose and peak concentration and a strong relationship between dose and plasma concentration time curve. Pharmacokinetic parameters of temozolomide were unaffected by the treatment schedule, so the difference in MTD between the schedules is likely due to a biologic rather than a pharmacokinetic sequence interaction. There were 9 partial responses among 43 patients evaluable for response, including 5 of 25 with a histologic diagnosis of glioblastoma. The recommended dose and schedule for phase II trials of this regimen are BCNU 150 mg/m2/i.v. followed in 2 h by temozolomide 550 mg/m2/p.o. repeated every 6 weeks. We are also recommending screening and periodic pulmonary function testing during treatment to assess the possible potentiation of nitrosourea-induced pulmonary fibrosis.
Collapse
|
73
|
Chang SM, Hou CL. Integument flaps incorporating the nutrifying arteries of cutaneous nerves and/or cutaneous veins. Plast Reconstr Surg 1999; 104:1210-2. [PMID: 10654780 DOI: 10.1097/00006534-199909040-00081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
74
|
Chang SM, Hutchinson SE, Powell CA, Walker SP. The nutritional status of rural Jamaican school children. W INDIAN MED J 1999; 48:112-4. [PMID: 10555453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Three thousand, eight hundred and eighty-two (3,882) children in grades 2-5, attending 16 rural primary and all-age schools in central Jamaica were weighed and their weight-for-age standard deviation scores calculated using the World Health Organization/National Center for Health Statistics (WHO/NCHS) references. Heights were also measured in a random sample of the grade 5 children (n = 793) and height-for-age and body mass index (BMI-kg/m2) calculated. Sixty-nine per cent of the total sample were of normal weight-for-age, 2% were moderately undernourished (weight-for-age > -3 Z-score, < or = -2 Z-score), and a further 24% mildly undernourished (weight-for-age > -2 Z-score, < or = -1 Z-score). Few children were overweight. The frequency distribution of weight-for-age was similar in girls and boys. In the subsample of children in whom heights were measured, 25.8% were < or = -1 Z-score height-for-age, and of these 4.9% were < -2 Z-score. Compared with a survey conducted in a similar rural area in the 1960s, the children's mean weights for age group categories were 1.1 to 3.7 kg heavier. Children who were older than appropriate for their grade were more likely to be undernourished (Odds ratio 3.94, 95% CI 3.21, 4.83), which suggests that undernourished children may be more likely to repeat a grade or start school later.
Collapse
|
75
|
Yung WK, Prados MD, Yaya-Tur R, Rosenfeld SS, Brada M, Friedman HS, Albright R, Olson J, Chang SM, O'Neill AM, Friedman AH, Bruner J, Yue N, Dugan M, Zaknoen S, Levin VA. Multicenter phase II trial of temozolomide in patients with anaplastic astrocytoma or anaplastic oligoastrocytoma at first relapse. Temodal Brain Tumor Group. J Clin Oncol 1999; 17:2762-71. [PMID: 10561351 DOI: 10.1200/jco.1999.17.9.2762] [Citation(s) in RCA: 517] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE To determine the antitumor efficacy and safety profile of temozolomide in patients with malignant astrocytoma at first relapse. PATIENTS AND METHODS This open-label, multicenter, phase II trial enrolled 162 patients (intent-to-treat [ITT] population). After central histologic review, 111 patients were confirmed to have had an anaplastic astrocytoma (AA) or anaplastic mixed oligoastrocytoma. Chemotherapy-naive patients were treated with temozolomide 200 mg/m(2)/d. Patients previously treated with chemotherapy received temozolomide 150 mg/m(2)/d; the dose could be increased to 200 mg/m(2)/d in the absence of grade 3/4 toxicity. Therapy was administered orally on the first 5 days of a 28-day cycle. RESULTS Progression-free survival (PFS) at 6 months, the primary protocol end point, was 46% (95% confidence interval, 38% to 54%). The median PFS was 5.4 months, and PFS at 12 months was 24%. The median overall survival was 13.6 months, and the 6- and 12-month survival rates were 75% and 56%, respectively. The objective response rate determined by independent central review of gadolinium-enhanced magnetic resonance imaging scans of the ITT population was 35% (8% complete response [CR], 27% partial response [PR]), with an additional 26% of patients with stable disease (SD). The median PFS for patients with SD was 4.4 months, with 33% progression-free at 6 months. Maintenance of progression-free status and objectively assessed response (CR/PR/SD) were both associated with health-related quality-of-life (HQL) benefits. Adverse events were mild to moderate, with hematologic side effects occurring in less than 10% of patients. CONCLUSION Temozolomide demonstrated good single-agent activity, an acceptable safety profile, and documented HQL benefits in patients with recurrent AA.
Collapse
|