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Baglan KL, Martinez AA, Frazier RC, Kini VR, Kestin LL, Chen PY, Edmundson G, Mele E, Jaffray D, Vicini FA. The use of high-dose-rate brachytherapy alone after lumpectomy in patients with early-stage breast cancer treated with breast-conserving therapy. Int J Radiat Oncol Biol Phys 2001; 50:1003-11. [PMID: 11429228 DOI: 10.1016/s0360-3016(01)01547-4] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE We present the preliminary results of our in-house protocol using outpatient high-dose-rate (HDR) brachytherapy as the sole radiation modality following lumpectomy in patients with early-stage breast cancer. METHODS AND MATERIALS Thirty-seven patients with 38 Stage I-II breast cancers received radiation to the lumpectomy cavity alone using an HDR interstitial implant with (192)Ir. A minimum dose of 32 Gy was delivered on an outpatient basis in 8 fractions of 4 Gy to the lumpectomy cavity plus a 1- to 2-cm margin over consecutive 4 days. RESULTS Median follow-up is 31 months. There has been one ipsilateral breast recurrence for a crude failure rate of 2.6% and no regional or distant failures. Wound healing was not impaired in patients undergoing an open-cavity implant. Three minor breast infections occurred, and all resolved with oral antibiotics. The cosmetic outcome was good to excellent in all patients. CONCLUSION In selected patients with early-stage breast cancer, treatment of the lumpectomy cavity alone with outpatient HDR brachytherapy is both technically feasible and well tolerated. Early results are encouraging, however, longer follow-up is necessary before equivalence to standard whole-breast irradiation can be established and to determine the most optimal radiation therapy technique to be employed.
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Chang LW, Chen PY, Kuo PL, Chang FM. Prenatal diagnosis of a fetus with megacystis and monosomy 21. Prenat Diagn 2001; 21:512-3. [PMID: 11438959 DOI: 10.1002/pd.86] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Vicini FA, Baglan KL, Kestin LL, Mitchell C, Chen PY, Frazier RC, Edmundson G, Goldstein NS, Benitez P, Huang RR, Martinez A. Accelerated treatment of breast cancer. J Clin Oncol 2001; 19:1993-2001. [PMID: 11283132 DOI: 10.1200/jco.2001.19.7.1993] [Citation(s) in RCA: 184] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Radiation therapy (RT) restricted to the tumor bed, by means of an interstitial implant, and lasting 4 to 5 days after lumpectomy was prospectively evaluated in early-stage breast cancer patients treated with breast-conserving therapy (BCT). The goals of the study were to determine whether treatment time can be reduced and whether elective treatment of the entire breast is necessary. MATERIALS AND METHODS Between January 1993 and January 2000, 174 cases of early-stage breast cancer were managed with lumpectomy followed by RT restricted to the tumor bed using an interstitial implant. Each brachytherapy patient was matched with one external-beam RT (ERT) patient derived from a reference group of 1,388 patients treated with standard BCT. Patients were matched for age, tumor size, histology, margins of excision, absence of an extensive intraductal component, nodal status, estrogen receptor status, and tamoxifen use. Median follow-up for both the ERT and brachytherapy groups was 36 months. RESULTS No statistically significant differences were noted in the 5-year actuarial rates of ipsilateral breast treatment failure or locoregional failure between ERT and brachytherapy patients (1% v 0%, P =.31 and 2% v 1%, P =.63, respectively). In addition, there were no statistically significant differences noted in rates of distant metastasis (6% v 3%, P =.24), disease-free survival (87% v 91%, P =.55), overall survival (90% v 93%, P =.66), or cause-specific survival (97% v 99%, P =.28). CONCLUSION Accelerated treatment of breast cancer using an interstitial implant to deliver radiation to the tumor bed alone over 4 to 5 days seems to produce 5-year results equivalent to those achieved with conventional ERT. Extended follow-up will be required to determine the long-term efficacy of this treatment approach.
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Frazier RC, Kestin LL, Kini V, Martinez AA, Chen PY, Baglan KL, Vicini FA. Impact of boost technique on outcome in early-stage breast cancer patients treated with breast-conserving therapy. Am J Clin Oncol 2001; 24:26-32. [PMID: 11232945 DOI: 10.1097/00000421-200102000-00004] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We reviewed our institution's experience treating early-stage breast cancer patients with breast-conserving therapy (BCT) to determine the impact of boost technique on outcome. A total of 552 patients with stage I and II breast cancer were managed with BCT. All patients were treated with a partial mastectomy and radiation therapy (RT). RT consisted of 45 Gy to 50 Gy external beam irradiation to the whole breast followed by a boost to the tumor bed using either electrons (232 patients), photons (15 patients), or an interstitial implant (316 patients). Local control and cosmetic outcome was compared among three patient groups based on the type of boost used. Forty-one patients had a recurrence of cancer in the treated breast for 5-, 10-, and 13-year actuarial local recurrence rates of 2.8%, 7.5%, and 11.2%, respectively. There were no significant differences in the local recurrence rates or cosmetic outcome using electrons, photons, or an interstitial implant. On multivariate analysis, only young age and margin status were associated with local recurrence. Stage I and II breast cancer patients undergoing BCT can be effectively managed with electron, photon, or interstitial implant boost techniques. Long-term local control and cosmetic outcome are excellent regardless of which boost technique is used.
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Ma JS, Chen PY, Chen CH, Chi CS. Neonatal fungemia caused by Hansenula anomala: a case report. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2000; 33:267-70. [PMID: 11269374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Hansenula anomala, an ascosporogenous yeast of the class Ascomycetes, is a free-living organism isolated from the environment. It is also a part of the normal or transient flora of the human throat and alimentary tract. It has been recognized as an opportunistic pathogen and its infection is very rare. A premature infant, a victim of right femoral osteomyelitis and right hip arthritis caused by oxacillin-resistant Staphylococcus aureus, was found to have developed H. anomala fungemia just before the initiation of the antimicrobial therapy with teicoplanin. Antifungal agents (fluconazole and amphotericin B) were prescribed for 10 days despite the absence of clinical sign of systemic fungal infection. His general condition remained good, with a subsequent sterile blood culture. The patient was discharged after completing 5 weeks of antimicrobial therapy, and he remained well during follow-up at our outpatient clinics. Here, we also review the risk factors, the clinical presentations, and the therapeutic strategies of H. anomala infection in the literature.
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Zerella R, Chen PY, Evans PA, Raine A, Williams DH. Structural characterization of a mutant peptide derived from ubiquitin: implications for protein folding. Protein Sci 2000; 9:2142-50. [PMID: 11152124 PMCID: PMC2144502 DOI: 10.1110/ps.9.11.2142] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The formation of the N-terminal beta-hairpin of ubiquitin is thought to be an early event in the folding of this small protein. Previously, we have shown that a peptide corresponding to residues 1-17 of ubiquitin folds autonomously and is likely to have a native-like hairpin register. To investigate the causes of the stability of this fold, we have made mutations in the amino acids at the apex of the turn. We find that in a peptide where Thr9 is replaced by Asp, U(1-17)T9D, the native conformation is stabilized with respect to the wild-type sequence, so much so that we are able to characterize the structure of the mutant peptide fully by NMR spectroscopy. The data indicate that U(1-17)T9D peptide does indeed form a hairpin with a native-like register and a type I turn with a G1 beta-bulge, as in the full-length protein. The reason for the greater stability of the U(1-17)T9D mutant remains uncertain, but there are nuclear Overhauser effects between the side chains of Asp9 and Lys 11, which may indicate that a charge-charge interaction between these residues is responsible.
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Lee SH, Huang JW, Hung KY, Leu LJ, Kan YT, Yang CS, Chung Wu D, Huang CL, Chen PY, Chen JS, Chen WY. Trace Metals' abnormalities in hemodialysis patients: relationship with medications. Artif Organs 2000; 24:841-4. [PMID: 11119069 DOI: 10.1046/j.1525-1594.2000.06352.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A multicenter collaborative study was performed to investigate the prevalence of abnormal blood contents of 6 trace metals, copper (Cu), zinc (Zn), aluminum (Al), lead (Pb), cadmium (Cd), and mercury (Hg), in hemodialysis (HD) patients and to analyze their relationship with the medications, such as CaCO3, Ca acetate, Al containing phosphate-binding agents, 1,25-dihydroxy vitD3, 1-hydroxy vitD3, and erythropoietin (EPO), as well as hematocrit level, by chi-square statistics. From 6 medical centers in Taiwan, we included 456 patients in maintenance HD for more than 4 months for this study, and they had continued the previously mentioned medications for at least 3 months. Blood samples were collected before initiating HD, and atomic absorption spectrophotometry was used to measure plasma levels of Cu, Zn, and Al as well as whole blood levels of Pb, Cd, and Hg. Three hundred seventy-five (78%) of the HD patients had low plasma Zn levels, that is, <800 microg/L, and the mean (+/-SD) concentration was 705.8 (+/-128.23) microg/L in all subjects. One hundred forty-one (31%) of the HD patients had high plasma Al, that is, >50 microg/L, and the mean (+/-SD) was 44.30 (+/-28.28) microg/L in all subjects. Three hundred thirty-three (73%) of the dialysis patients had high Cd levels, that is, >2.5 microg/L, and the mean (+/-SD) was 3.32 (+/-1.49) microg/L in all subjects. The majority of HD patients had normal blood levels of Cu, PB, and Hg. Only 21 (4. 6%), 5 (1.1%), and 3 (0.06%) patients had elevated blood levels of Cu, Pb, and Hg, respectively. Their mean (+/-SD) blood concentration of Cu, Pb, and Hg were 1,049.78 (+/-233.25) microg/L, 7.45 (+/-3.95) microg/dL, and 3.17 (+/-25.56) microg/L, respectively. Three patients had elevated plasma Hg concentrations, that is, 546, 12.6, and 24.0 microg/L, respectively. In the 152 normal healthy age and sex matched control group, the blood levels of Al, Cd, and Pb were all significantly lower than the HD patients. However, the levels of Cu and Zn were higher in the control group. The Hg level was not significantly different in both groups. There was no statistical difference between patients with normal and abnormal blood levels of trace metals in various medications except Al containing phosphate binder. The Al containing phosphate binder users had significantly higher plasma Al levels (54.71 +/- 26.70 versus 41.15 +/- 28.03 microg/L, p < 0.001) and hematocrit levels (29.61 +/- 4.61 versus 27. 81 +/- 3.91, p < 0.0005). There was no statistical correlation between erythropoietin (EPO) dose and hematocrit level in these patients. In conclusion, the blood level of trace metals of these HD patients except Al was not related to their medications. However, caution must be exercised in interpreting this result as dose and duration of medication; efficiency of HD and water treatment may play an important role. Otherwise, environmental factors, diet, and the aging process may contribute to the trace metal burden in uremia. Thus, Zn and Cu are abundant in seafood, and Cd is abundant in contaminated plants such as rice.
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Ma JS, Chen PY, Chi CS, Lin JF, Lau YJ. Invasive Streptococcus pneumoniae infections of children in central Taiwan. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2000; 33:169-75. [PMID: 11045380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
We carried out a retrospective study on childhood invasive pneumococcal infections (IPI) diagnosed from the January 1990 through the April 2000 at a medical center in central Taiwan. Their clinical features, outcome of the patients and the resistance patterns of the isolates were analyzed. A total of 95 clinical isolates from 72 patients younger than 14 years of age were included in this study. Of these 72 patients, 51 had bacteremia, 28 meningitis, 14 bacteremic pneumonia, 12 pleural empyema, eight otitis media, four arthritis, three sinusitis, two periorbital abscesses, one deep neck infection, one psoas muscle abscess, one peritonitis, one urinary tract infection, and one cutaneous infection. Ancillary diagnostic tests, including Gram stain smears and latex agglutination tests, were applied and the sensitivities were 86.2% and 54.3%, respectively. The prevalence rate of penicillin nonsusceptible Streptococcus pneumoniae has increased dramatically since 1995 in central Taiwan, with rates of 5.6% and 74.1% before and after 1995, and the overall mortality rate was 20.8% and 53.3% respectively. Ten of 19 children (52.6%) with pneumococcal meningitis who survived had long-term sequelae.
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Jan SL, Chi CS, Hwang B, Fu YC, Chen PY, Mak SC. Cardiac manifestations of fatal enterovirus infection during the 1998 outbreak in Taiwan. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 2000; 63:612-8. [PMID: 10969447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
BACKGROUND An outbreak of hand-foot-and-mouth disease caused by enterovirus infection occurred in Taiwan in 1998 and more than 70 infants and children with fulminant courses died. We compared the cardiac manifestations of fatal cases with patients who survived the enterovirus infection. METHODS A total 187 patients with enterovirus infection were treated at Taichung Veterans General Hospital between April and June 1998. Enterovirus infection was diagnosed by history, clinical features, polymerase chain reaction study and/or viral culture. Cardiac examinations including complete physical examinations, electrocardiography and echocardiography were performed on seven cases (group I) with or without central nervous system (CNS) involvement, 30 patients with CNS involvement (group II), and 150 patients without CNS involvement (group III). RESULTS There were no significant differences in sex distribution, days of fever, heart rate, systemic blood pressure or time from the onset of symptoms to hospital admission among the three groups. All group I patients had features of acute congestive heart failure, pulmonary edema and neurologic signs except one who presented with right-sided heart failure and neurologic signs. The echocardiographic findings of group I were a lower fractional shortening, lower ejection fraction, and more severe and higher incidence of mitral regurgitation (p < 0.01) than in groups II and III, but there were no significant differences in end-systolic wall stress, left ventricular end-diastolic internal dimension and incidence of pericardial effusion among the three groups. CONCLUSIONS We conclude that seven infants and children (group I) died due to either severe cardiomyopathy or encephalopathy. The possible pathogenesis of enterovirus infection leading to death is reviewed and analyzed.
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Kestin LL, Martinez AA, Stromberg JS, Edmundson GK, Gustafson GS, Brabbins DS, Chen PY, Vicini FA. Matched-pair analysis of conformal high-dose-rate brachytherapy boost versus external-beam radiation therapy alone for locally advanced prostate cancer. J Clin Oncol 2000; 18:2869-80. [PMID: 10920135 DOI: 10.1200/jco.2000.18.15.2869] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE We performed a matched-pair analysis to compare our institution's experience in treating locally advanced prostate cancer with external-beam radiation therapy (EBRT) alone to EBRT in combination with conformal interstitial high-dose-rate (HDR) brachytherapy boosts (EBRT + HDR). MATERIALS AND METHODS From 1991 to 1998, 161 patients with locally advanced prostate cancer were prospectively treated with EBRT + HDR at William Beaumont Hospital, Royal Oak, Michigan. Patients with any of the following characteristics were eligible for study entry: pretreatment prostate-specific antigen (PSA) level of >/= 10.0 ng/mL, Gleason score >/= 7, or clinical stage T2b to T3c. Pelvic EBRT (46.0 Gy) was supplemented with three (1991 through 1995) or two (1995 through 1998) ultrasound-guided transperineal interstitial iridium-192 HDR implants. The brachytherapy dose was escalated from 5.50 to 10.50 Gy per implant. Each of the 161 EBRT + HDR patients was randomly matched with a unique EBRT-alone patient. Patients were matched according to PSA level, Gleason score, T stage, and follow-up duration. The median PSA follow-up was 2.5 years for both EBRT + HDR and EBRT alone. RESULTS EBRT + HDR patients demonstrated significantly lower PSA nadir levels (median, 0.4 ng/mL) compared with those receiving EBRT alone (median, 1.1 ng/mL). The 5-year biochemical control rates for EBRT + HDR versus EBRT-alone patients were 67% versus 44%, respectively (P <.001). On multivariate analyses, pretreatment PSA, Gleason score, T stage, and the use of EBRT alone were significantly associated with biochemical failure. Those patients in both treatment groups who experienced biochemical failure had a lower 5-year cause-specific survival rate than patients who were biochemically controlled (84% v 100%; P <.001). CONCLUSION Locally advanced prostate cancer patients treated with EBRT + HDR demonstrate improved biochemical control compared with those who are treated with conventional doses of EBRT alone.
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Ma JS, Chen PY, Fu LS, Chi CS, Huang YF, Lin CY, Shieh CC. Chronic granulomatous disease: a case report. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2000; 33:118-22. [PMID: 10917883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Chronic granulomatous disease (CGD) is a rare inherited disorder caused by defects in the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex of phagocytic leukocytes. The leukocytes of the CGD patients cannot produce adequate amount of superoxide and other oxygen metabolites which are toxic to microorganisms. As a result, the phagocytes fail to kill the ingested microorganisms, especially those with catalase activity. Typically, CGD patients suffer from recurrent pyogenic infections starting from the first year of life. We report a young boy who had experienced recurrent perianal abscess, osteomyelitis and bacterial enterocolitis. Flow cytometric analysis revealed defects in the neutrophil respiratory burst pathway and defined the carrier state of his mother and younger sister. He received antimicrobial prophylaxis at our out-patient clinics and remained well at present. We try to make clinical physician keep in mind the diagnosis of CGD by presenting this typical case. In the meantime, we review the recent literature regarding the advances in diagnosis and management of CGD.
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Lin IJ, Chen CH, Chen PY, Wang TM, Chi CS. Nosocomial infection in a neonatal intensive care unit--from a viewpoint of national health insurance. ACTA PAEDIATRICA TAIWANICA = TAIWAN ER KE YI XUE HUI ZA ZHI 2000; 41:123-8. [PMID: 10920543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
In order to survey both the epidemiology of nosocomial infection in our neonatal intensive care unit (NICU) and the changing face of nosocomial infection after the introduction of National Health Insurance (NHI) in Taiwan, we retrospectively reviewed the nosocomial infections which occurred in our NICU from March 1, 1991, to February 28, 1999. We also compared the nosocomial infections from the viewpoint of NHI. The mean rate of nosocomial infections in our NICU during these 8 years was 13.6%, and it had significantly increased after the NHI plan was implemented (from 7.9% to 19.0%). The most common type of nosocomial infection was blood stream infection (53.8%, 120 of 223 infections). Coagulase-negative Staphylococci and fungi were the two most common pathogens of nosocomial blood stream infection in our NICU, accounting for 28.1% and 24.2% of the infections, respectively. The survival rate of very low birth weight (VLBW) infants increased from 76.3% to 78.4% after the implementation of NHI. However, the nosocomial infection rate of the VLBW infants had markedly increased from 22.6% to 41.9%. The total number of hospitalization days of the patients with nosocomial infection was significantly greater than that of those without nosocomial infections (p < 0.05), and the patients with the lower birth weights had longer hospital stays. The risk factors for nosocomial infection including invasive procedures, multiple and empirical antibiotics, and extremely low birth weight premature infants, remained the same, but the prevalence of nosocomial infection in the neonatal intensive care unit has changed markedly since the NHI plan began. Further investigation to determine strategies for preventing nosocomial infection in very low birth weight infants is warranted.
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Fan KT, Lee TH, Yu KL, Tang CS, Lu DV, Chen PY, Soo LY. Influences of tramadol on emergence characteristics from sevoflurane anesthesia in pediatric ambulatory surgery. Kaohsiung J Med Sci 2000; 16:255-60. [PMID: 10969521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Sevoflurane is used for pediatric ambulatory surgery due to its low blood solubility, rapid emergence, non-pungency and low airway irritability. Nevertheless, its tendency to induce agitation during emergence may offset its benefits. The following study was designed to evaluate the effects of intravenous (i.v.) tramadol (1 mg/kg) on the emergence from sevoflurane anesthesia. Forty ASA I children, ranging from 1 to 8 years old, scheduled for inguinal surgery, were randomized into two groups (Group S--control group, Group ST--i.v. tramadol, 20 in each group). The patients were first premedicated with oral atropine (0.01 mg/kg), then anesthesia was induced with i.v. application of thiamylal (3-4 mg/kg) and maintained with mask anesthesia with sevoflurane. Topical infiltration with 2-3 ml of 1% lidocaine was applied over skin incision area. I.v. tramadol (1 mg/kg) was given before the end of operation in Group ST. The emergence agitation was recorded on a visual analog scale (VAS, 0-10) by a blinded anesthesiologist in the PACU (postoperative anesthesia care unit), as well as the length of other recovery stages and complications after anesthesia. The age, weight, gender, and duration of surgery and anesthesia were similar in the two groups. The emergence agitation score (6.3 +/- 3.5 vs. 3.2 +/- 2.8, P < 0.05), incidences of agitation (VAS > 5, 55% vs 20%, P < 0.05), and postoperative pain (65% vs 30%, P < 0.05) were higher for the control group. I.v. Tramadol (1 mg/kg) before the end of operation reduced postoperative pain and the incidence and degree of emergence agitation from sevoflurane anesthesia in pediatric ambulatory surgery.
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Spector PE, Chen PY, O'Connell BJ. A longitudinal study of relations between job stressors and job strains while controlling for prior negative affectivity and strains. JOURNAL OF APPLIED PSYCHOLOGY 2000; 85:211-8. [PMID: 10783537 DOI: 10.1037/0021-9010.85.2.211] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Interpretation of observed relations between job stressors and job strains in cross-sectional surveys is often ambiguous because of possible 3rd variables (both stable background factors, such as personality, and transitory occasion factors, such as mood). In this longitudinal study, negative affectivity (NA) and strains were assessed both in college and later on the job. Stressors were assessed only on the job. Evidence was found that some background factors affected measures of job stressors and job strains in that college measures were significantly related to subsequent measures on the job. Relations between job stressors and job strains, however, were in most cases not affected significantly when prior strains and NA were controlled for. Furthermore, the results suggested that NA measures are subject to occasion factors.
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Peng J, Chen PY, Marchase RB, Prestwich GD. Preparation and use of a photoactivatable glucose-6-phosphate analogue. Bioorg Med Chem Lett 2000; 10:535-9. [PMID: 10741548 DOI: 10.1016/s0960-894x(00)00043-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A benzophenone-containing derivative of glucose-6-phosphate, 6-[(3-([2,3-3H2]-p-benzoyl dihydrocinnamidoylpropyl-1-oxy)phosphoryl]-D-glucopyranose ([3H]BZDC-Glc-6-P) was synthesized and employed to photoaffinity label proteins on intact rat liver microsomes. The use of a non-photoactivatable, UV-transparent desoxy analogue of BZDC, named p-benzyldihydrocinnamoyl (BnDC), is introduced as a general method to achieve competition when hydrophilic ligands are modified with hydrophobic photophores.
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Jiang P, Chen PY, Dong YY, Cai JL, Cai BX, Jiang ZH. Isolation and genome characterization of porcine reproductive and respiratory syndrome virus in P.R. China. J Vet Diagn Invest 2000; 12:156-8. [PMID: 10730947 DOI: 10.1177/104063870001200211] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Kestin LL, Jaffray DA, Edmundson GK, Martinez AA, Wong JW, Kini VR, Chen PY, Vicini FA. Improving the dosimetric coverage of interstitial high-dose-rate breast implants. Int J Radiat Oncol Biol Phys 2000; 46:35-43. [PMID: 10656370 DOI: 10.1016/s0360-3016(99)00361-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE/OBJECTIVE We performed a retrospective computed tomography (CT)-based three-dimensional (3D) dose-volume analysis of high-dose-rate (HDR) interstitial breast implants to evaluate the adequacy of lumpectomy cavity coverage, and then designed a simple, reproducible algorithm for dwell-time adjustment to correct for underdosage of the lumpectomy cavity. METHODS AND MATERIALS Since March 1993, brachytherapy has been used as the sole radiation modality after lumpectomy in selected protocol patients with early-stage breast cancer treated with breast-conserving therapy. In this protocol, all patients received 32 Gy in 8 fractions of 4 Gy over 4 days. Eleven patients treated with HDR brachytherapy who underwent CT scanning after implant placement were included in this analysis. For each patient, the postimplant CT dataset was transferred to a 3D treatment planning system, and the relevant tissue volumes were outlined on each axial slice. The implant dataset, including the dwell positions and dwell times, were imported into the 3D planning system and then registered to the visible implant template in the CT dataset. The calculated dose distribution was analyzed with respect to defined volumes via dose-volume histograms. Due to the variability of lumpectomy cavity coverage discovered in this 3D quality assurance analysis, dwell times at selected positions were adjusted in an attempt to improve dosimetric coverage of the lumpectomy cavity. Using implant data from 5 cases, a dwell-time adjustment algorithm was designed and was then tested on 11 cases. In this algorithm, a point P was identified using axial CT images, which was representative of the underdosed region within the cavity. The distance (d) from point P to the nearest dwell position was measured. A number of dwell positions (N) nearest to point P were selected for dwell time adjustment. The algorithm was tested by increasing the dwell times of a variable number of positions (N = 1, 3, 5, 7, 10, and 20) by a weighting factor (alpha), where alpha = f(d) and alpha > 1, and subsequently performing 3D dose-volume analysis to evaluate the improvement in lumpectomy cavity coverage. RESULTS Before adjustment in the 11 implants, the median proportion of the lumpectomy cavity and target volume that received at least the prescription dose was 85% and 68%, respectively. After dwell-time adjustment, lumpectomy cavity coverage was significantly improved in all 11 cases. The median distance from point P to the nearest dwell position (d) was 1.4 cm (range 0.9-1.9). The median volume of the lumpectomy cavity receiving 32 Gy increased from 85.3% in the actual implant to 97.0% (range 74-100%) by increasing the dwell time of a single dwell position by a median factor (alpha) of 12.2 according to the above algorithm. With N = 3, the median proportion of the cavity volume receiving 32 Gy was improved to 97.5% (range 77-100%), with a median alpha of 5.7. Further improvement in lumpectomy cavity coverage was relatively small by increasing additional dwell times. In addition, with N = 20, the median absolute volume of breast tissue receiving 150% of the prescription dose was 70.3 cm3 compared to 26.3 cm3 in the actual implant; whereas with N = 1 or N = 3, this median volume was only 35.9 and 42.0 cm3, respectively. CONCLUSION Lumpectomy cavity coverage sometimes appears suboptimal with interstitial HDR breast brachytherapy using our current technique. A simple dwell-time increase at only 1-3 dwell positions can compensate for some underdosage without creating significant regions of overdosage. Using simple methodology, a single reference point representing the underdosed region can be utilized for initial selection of the dwell positions to be increased.
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Vicini FA, Kestin LL, Goldstein NS, Chen PY, Pettinga J, Frazier RC, Martinez AA. Impact of young age on outcome in patients with ductal carcinoma-in-situ treated with breast-conserving therapy. J Clin Oncol 2000; 18:296-306. [PMID: 10637243 DOI: 10.1200/jco.2000.18.2.296] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE We reviewed our institution's experience treating patients with ductal carcinoma-in-situ (DCIS) with breast-conserving therapy (BCT) to determine the impact of patient age on outcome. PATIENTS AND METHODS From 1980 to 1993, 146 patients were treated with BCT for DCIS. All patients underwent excisional biopsy, and 64% underwent re-excision. All patients received whole-breast irradiation to a median dose of 45 Gy. Ninety-four percent of patients received a boost to the tumor bed, for a median total dose of 60.4 Gy. All slides on every patient were reviewed by one pathologist. The median follow-up period was 7.2 years. RESULTS Seventeen patients developed an ipsilateral local recurrence, for 5- and 10-year actuarial rates of 10.2% and 12.4%, respectively. The 10-year rate of ipsilateral failure was 26.1% in patients younger than 45 years of age versus 8.6% in older patients (P =.03). On multivariate analysis, young age was independently associated with recurrence of the index lesion (true recurrence/marginal miss ¿TR/MM failures), regardless of how it was analyzed (eg, < 45 years of age or as a continuous variable). In addition, young patients had a dramatically higher 10-year rate of invasive TR/MM failures (19.9% v 3.2%). In a separate multivariate analysis for the development of invasive TR/MM failures, only patient age and predominant nuclear grade were independently associated with recurrence. The relationship between excision volume and outcome was analyzed in the 95 patients who underwent re-excision. The 5-year actuarial rate of TR/MM failure was significantly worse only in young patients with smaller (< 40 mL) re-excision volumes (33.3% v 9.1%; P =.02). In a separate multivariate analysis of only these 95 patients (25 of whom were < 45 years of age), the volume of re-excision had the strongest association with outcome (P =.05). Patient age was no longer associated with local recurrence. CONCLUSION These findings suggest that young patients with DCIS have a significantly greater risk of local recurrence after BCT that is independent of other previously defined risk factors. Our data also suggest that the extent of resection may in part be related to the less optimal results that are observed in these patients.
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Vicini FA, Kestin LL, Edmundson GK, Jaffray DA, Wong JW, Kini VR, Chen PY, Martinez AA. Dose-volume analysis for quality assurance of interstitial brachytherapy for breast cancer. Int J Radiat Oncol Biol Phys 1999; 45:803-10. [PMID: 10524437 DOI: 10.1016/s0360-3016(99)00174-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE/OBJECTIVE The use of brachytherapy in the management of breast cancer has increased significantly over the past several years. Unfortunately, few techniques have been developed to compare dosimetric quality and target volume coverage concurrently. We present a new method of implant evaluation that incorporates computed tomography-based three-dimensional (3D) dose-volume analysis with traditional measures of brachytherapy quality. Analyses performed in this fashion will be needed to ultimately assist in determining the efficacy of breast implants. METHODS AND MATERIALS Since March of 1993, brachytherapy has been used as the sole radiation modality after lumpectomy in selected protocol patients with early-stage breast cancer treated with breast-conserving therapy. Eight patients treated with high-dose-rate (HDR) brachytherapy who had surgical clips outlining the lumpectomy cavity and underwent computed tomography (CT) scanning after implant placement were selected for this study. For each patient, the postimplant CT dataset was transferred to a 3D treatment planning system. The lumpectomy cavity, target volume (lumpectomy cavity plus a 1-cm margin), and entire breast were outlined on each axial slice. Once all volumes were entered, the programmed HDR brachytherapy source positions and dwell times were imported into the 3D planning system. Using the tools provided by the 3D planning system, the implant dataset was then registered to the visible implant template in the CT dataset. The distribution of the implant dose was analyzed with respect to defined volumes via dose-volume histograms (DVH). Isodose surfaces, the dose homogeneity index, and dosimetric coverage of the defined volumes were calculated and contrasted. All patients received 32 Gy to the entire implanted volume in 8 fractions of 4 Gy over 4 days. RESULTS Three-plane implants were used for 7 patients and a two-plane implant for 1 patient. The median number of needles per implant was 16.5 (range 11-18). Despite visual verification by the treating physician that surgical clips (with an appropriate margin) were within the boundaries of the implant needles, the median proportion of the lumpectomy cavity that received the prescribed dose was only 87% (range 73-98%). With respect to the target volume, a median of only 68% (range 56-81%) of this volume received 100% of the prescribed dose. On average, the minimum dose received by at least 90% of the target volume was 22 Gy (range 17.3-26.9), which corresponds to 69% of the prescribed dose. CONCLUSION Preliminary results using our new technique to evaluate implant quality with CT-based 3D dose-volume analysis appear promising. Dosimetric quality and target volume coverage can be concurrently analyzed, allowing the possibility of evaluating implants prospectively. Considering that target volume coverage may be suboptimal even after radiographically verifying accurate implant placement, techniques similar to this need to be developed to ultimately determine the true efficacy of brachytherapy in the management of breast cancer.
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Cheng RJ, Chen PY. Bonding Characteristics Mediated by Saddle-Shaped Porphyrin Deformation: A Theoretical Approach to the Control of Spin State of Iron(III) Porphyrins. Chemistry 1999. [DOI: 10.1002/(sici)1521-3765(19990604)5:6<1708::aid-chem1708>3.0.co;2-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Chen PY, Wu HM, Kuo PL, Tzeng CC. Unusual chromosome 9 variant with an extra G-dark and C-negative segment in the short arm, proximal to the centromere: a case study. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1999; 62:121-4. [PMID: 10063724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Polymorphic variation of constitutive heterochromatin in human chromosomes is commonly seen in clinical cytogenetic analyses. Normal variant can be confirmed with C-banding and are generally considered clinically insignificant. However, it may be a concern if an unusual variant chromosome is detected in a prenatal specimen. We report an unusual chromosome 9 variant with an extra G-dark and C-negative segment in the short arm, proximal to the centromere. This chromosome 9 variant has been previously reported in only nine independent families. Whether this is a rare variant or an underestimation requires further evaluation. Of note is that all probands so far reported in the literature are clinically normal.
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Chen PY, Popovich PM, Kogan M. Let's talk: patterns and correlates of social support among temporary employees. J Occup Health Psychol 1999; 4:55-62. [PMID: 10100113 DOI: 10.1037/1076-8998.4.1.55] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The authors explored how temporary employees exchanged communications with supervisor, peers, and family and friends regarding positively job-related, negatively job-related, and non-job-related contents. The authors also examined roles of communication in coping with insecure job experiences. Survey results from 112 temporary employees working in various organizations provided evidence that communication contents were differentially related to work anxiety and life satisfaction for temporary employees. It was found that work anxiety increased when employees engaged in communication pertaining to negative job-related contents. Furthermore, the positive relationship between life satisfaction and positive communication with coworkers was observed only for the temporary employees who also had a permanent job. Implications for staffing temporary employees and suggestions for studying communication effects are discussed.
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Chen PY, Csutora P, Veyna-Burke NA, Marchase RB. Glucose-6-phosphate and Ca2+ sequestration are mutually enhanced in microsomes from liver, brain, and heart. Diabetes 1998; 47:874-81. [PMID: 9604862 DOI: 10.2337/diabetes.47.6.874] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Microsomes prepared from three rat tissues were examined for their ability to import glucose-6-phosphate (G-6-P). Microsomes from liver, which possess a high level of glucose-6-phosphatase activity, were compared with those from cerebral cortex and cardiac muscle, which are not involved in the export of glucose and in which glucose-6-phosphatase activity is relatively low. In all three, a selective permeability to G-6-P was detected by light scattering. However, the sugar-phosphate specificity of the transport process differed. G-6-P was able to enhance ATP-dependent Ca2+ sequestration in all three types of microsomes. In addition, enzymatic detection of G-6-P after the rapid filtration of microsomes determined that, in the absence of Ca2+ and ATP, a level of intramicrosomal G-6-P approaching a passive equilibrium with the extramicrosomal G-6-P concentration was rapidly achieved in all three tissues. However, under conditions in which Ca2+ was being actively accumulated, the intramicrosomal levels of G-6-P exceeded the equilibrium value by three- to fourfold. This enhanced sequestration was not observed in the presence of Ca2+ or ATP alone or in the presence of a Ca2+ ionophore or an inhibitor of the microsomal Ca2+ ATPase. These data are consistent with a selective import pathway into the endoplasmic/sarcoplasmic reticulum for G-6-P independent of glucose-6-phosphatase activity. In addition, they suggest an alternate explanation for the enhanced sequestration of Ca2+ by the endoplasmic/sarcoplasmic reticulum of intact cells seen when extracellular glucose is increased.
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Wood PA, Hamm DA, Chen PY, Sanders PW. Studies of arginine metabolism and salt sensitivity in the Dahl/Rapp rat models of hypertension. Mol Genet Metab 1998; 64:80-3. [PMID: 9682223 DOI: 10.1006/mgme.1998.2696] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies by our group demonstrated a striking relationship among arginine, nitric oxide production, and salt-sensitive hypertension in the Dahl/Rapp rat. We hypothesized that enzymes of the urea cycle may be involved in this process. We specifically examined the activities of liver and kidney argininosuccinate synthetase (AS), because this enzyme is an essential step of arginine synthesis and a likely control point. We found that salt-sensitive (S) rats on a high-salt diet developed hypertension without change in plasma concentrations of arginine, citrulline, and ornithine. Baseline plasma concentrations of these amino acids were the same in rats of all three genotypes: Sprague-Dawley (SD), S, and salt-resistant (R) Dahl/Rapp rats. In contrast, R rats on the high-salt diet remained normotensive coincidentally with elevated levels of arginine and ornithine, as compared to normotensive R rats on low-salt diet with no changes in amino acid concentrations. S rats on high-salt diet became hypertensive coincidentally with no changes in amino acid concentrations. None of the rat groups had significantly different activity of liver of kidney AS coincidental with the salt in the diet and the changes in amino acid concentrations found in the R rats. Thus, given the lack of alteration in plasma concentrations of the urea cycle amino acids of arginine, citrulline, and ornithine in S rats, genes of the urea cycle/arginine synthesis are unlikely to be involved in salt-sensitive hypertension in this strain. The mechanism of increased plasma arginine and ornithine concentrations in R rats was not determined, but was not related to AS activity.
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Bellarosa C, Chen PY. The effectiveness and practicality of occupational stress management interventions: a survey of subject matter expert opinions. J Occup Health Psychol 1998. [PMID: 9552295 DOI: 10.1037//1076-8998.2.3.247] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Stress management (SM) subject matter experts (SMEs) evaluated 6 widely used occupational SM interventions (relaxation, physical fitness, cognitive restructuring, meditation, assertiveness training, and stress inoculation) on the basis of 10 practicality criteria and 7 effectiveness objectives. Relaxation was evaluated overall as the most practical intervention, while meditation and stress inoculation were judged as the least practical. Physical fitness was chosen to be the most effective intervention, while both meditation and assertiveness training were rated overall as the least effective. The findings also revealed that the SMEs considered history of success and duration of effect, rather than "relevance to program objectives," as the most important factors when selecting SM interventions. Incongruence between effectiveness ratings and actual choices of interventions are discussed.
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