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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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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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Chen PY, Gladish RD, Sanders PW. Vascular smooth muscle nitric oxide synthase anomalies in Dahl/Rapp salt-sensitive rats. Hypertension 1998; 31:918-24. [PMID: 9535415 DOI: 10.1161/01.hyp.31.4.918] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Salt-sensitive hypertension in the Dahl/Rapp rat (S strain) is prevented by L-arginine. Based on the observations that dexamethasone prevented the antihypertensive effect of L-arginine in these animals and the suggestion that a locus in or near an inducible nitric oxide synthase (NOS) gene on chromosome 10 cosegregated with hypertension in some F2 crosses that utilized the S rat, the present study explored the hypothesis that the vascular smooth muscle isoform of inducible NOS (NOS2) was abnormal in S rats. Primary cultures of aortic smooth muscle cells from S rats demonstrated impaired inducible NO production, which improved with increased L-arginine in the medium. Sequence analysis identified a single T-->C transversion that produced an amino acid substitution (S714P) between the FAD and FMN binding sites and a restriction fragment length polymorphism. This restriction fragment length polymorphism was present only in S rats. The mutation of NOS2 and the role of this enzyme in the pathogenesis of salt-sensitive hypertension in the Dahl/Rapp rat require further investigation.
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Victor SJ, Brown DM, Horwitz EM, Martinez AA, Kini VR, Pettinga JE, Shaheen KW, Benitez P, Chen PY, Vicini FA. Treatment outcome with radiation therapy after breast augmentation or reconstruction in patients with primary breast carcinoma. Cancer 1998; 82:1303-9. [PMID: 9529022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Analyses were performed to determine local control and cosmetic outcome of breast carcinoma patients with prosthetically augmented or reconstructed breasts who had received radiation therapy (RT). METHODS Twenty-one newly diagnosed breast carcinoma patients with prosthetically augmented or reconstructed breasts were treated with external beam RT. All patients received whole breast RT (median dose, 50.4 gray [Gy]) and 19 were boosted to a median dose of 60.4 Gy. A median dose of 50.4 Gy was delivered to the regional lymph nodes in 12 patients. Tissue equivalent bolus material was used in six patients. Seventeen patients received adjuvant systemic therapy. Cosmetic results were evaluated at 3-6-month intervals. RESULTS With a median follow-up of 32 months, good/excellent cosmetic results were observed in 71% of patients (100% in those with augmented breasts and 54% in those with reconstructed breasts). Four patients (19%) with fair/poor cosmetic outcomes required implant removal and/or revision. Multiple clinical and treatment-related factors were analyzed for their impact on cosmetic outcome. A worsened cosmetic result was observed with increasing stage (P = 0.076), breast reconstruction (vs. augmentation) (P = 0.030), and bolus application (P = 0.016). All patients with fair/poor cosmetic outcomes had time intervals from implant insertion to RT ranging from 53-213 days. Two patients developed an isolated local recurrence within the augmented breast. CONCLUSIONS Patients with prosthetically augmented breasts can undergo RT and expect good/excellent cosmetic results. Patients with reconstructed breasts are at a significantly greater risk for cosmetic failure. This risk may be related to the higher percentage of patients with advanced disease, those who received bolus application, and those who received earlier delivery of RT (after the cosmetic procedure) in reconstructed breasts.
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Hsiao CH, Chen JJ, Huang SC, Ma HK, Chen PY, Tsai RJ. Intrascleral dissemination of infectious scleritis following pterygium excision. Br J Ophthalmol 1998; 82:29-34. [PMID: 9536876 PMCID: PMC1722356 DOI: 10.1136/bjo.82.1.29] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
AIMS To assess the clinical pictures, possible pathogenesis, management, and therapy of patients with infectious scleritis associated with multifocal scleral abscesses following pterygium excision. METHODS The records of patients with infectious scleritis after pterygium excision who developed multifocal scleral abscesses presenting from 1988 to the end of 1995 were reviewed. Early culture of abscesses was performed, and topical, systemic antimicrobials, or both were given to all patients. Fourteen eyes were operated on in addition to antimicrobial treatment. RESULTS The initial culture reports of scleral ulcers identified Pseudomonas species in 12 of these 18 patients, Aspergillus in one, Mycobacterium fortuitum in one, and mixed organisms in four. Subsequent abscess cultures were taken from 15 of the infected eyes, and revealed the same organism as the initial culture in 12. Associated complications included four serous retinal detachments, three choroidal detachments, two double detachments, five complicated cataracts, and four recurrences of the initial infection. Four eyes required eventual enucleation and 11 eyes regained useful vision. CONCLUSIONS With subsequent abscess cultures proving to be the same organism as found in the initial ulcer, the abscess formation appears to represent intrascleral dissemination. Early diagnosis and appropriate, prolonged topical plus systemic antimicrobial treatment are essential to halt the progression of such severe infections.
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Hung KY, Ho CY, Kuo YM, Lee SH, Hseih SJ, Yang CS, Peng CJ, Wu DJ, Hung JT, Chen PY, Chen JS, Chen WY. Trace elements burden in geriatric hemodialysis patients: a prospective multicenter collaborative study. Int J Artif Organs 1997; 20:553-6. [PMID: 9422489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Hemodialysis therapy and the aging process have been reported to interfere with the trace element (TE) status in the body. This multicenter collaborative study on blood levels of TE in geriatric hemodialysis (HD) patients was carried out with an aim to clarify the impact of the aging process and HD therapy on the TE status in such patients. METHODS One hundred and fifty-one HD patients (65 male, 86 female), all aged over 60 (68.2+/-3.86 y), and 112 elderly controls (58 male, 54 female) with a mean age of 67.5+/-3.03 were enrolled. All patients underwent standard HD for at least 6 months. The artificial kidneys used were hollow-fiber dialyzers of cellulose membranes. Water used for HD was prepared by reverse osmosis. Blood was collected in the morning prior to dialysis and after fasting. Atomic absorption spectrophotometry was applied to measure blood levels of Pb, Cd and Hg as well as plasma levels of Cu, Zn and Al. Data are presented as mean +/- SEM. Student's t-test and linear regression were applied for statistics. RESULTS Our geriatric chronic HD patients showed a marked elevation of blood Al and decreased plasma Zn concentrations. The blood levels of Cu, Cd, Pb and Hg were within normal limits. The blood concentrations of Al, Cu and Pb were significantly higher in HD patients than in the normal elderly controls, whereas Cd and Hg were similar in both groups, and Zn were lower in HD patients. Plasma Zn value decreased as dialysis duration increased, however there was a reversely linear correlation between plasma Zn and age. CONCLUSIONS This data reported can be regarded as a starting point and may serve as an insight to further studies on TE imbalances in geriatric and chronic HD populations.
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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 1997; 2:247-62. [PMID: 9552295 DOI: 10.1037/1076-8998.2.3.247] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [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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DeBiose DA, Horwitz EM, Martinez AA, Edmundson GK, Chen PY, Gustafson GS, Madrazo B, Wimbish K, Mele E, Vicini FA. The use of ultrasonography in the localization of the lumpectomy cavity for interstitial brachytherapy of the breast. Int J Radiat Oncol Biol Phys 1997; 38:755-9. [PMID: 9240643 DOI: 10.1016/s0360-3016(97)00069-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE To determine the value of breast ultrasonography (US) in defining the lumpectomy cavity for patients treated with interstitial brachytherapy. METHODS AND MATERIALS In March 1993, a protocol of low dose rate (LDR) interstitial brachytherapy as the sole radiation modality in selected patients with early breast cancer was initiated at William Beaumont Hospital. To date, 60 patients have been entered in this protocol, and 38 have undergone US assisted placement of interstitial brachytherapy needles. The lumpectomy cavity was outlined in all dimensions and corresponding skin marks were placed for reference at time of implantation. These US dimensions were compared to the physician's clinical estimate of the location of the lumpectomy cavity, the patient's presurgical mammogram, and the position of the surgical scar. In the intraoperative setting, the dimensions of the lumpectomy cavity were also obtained and the placement of the deep plane of interstitial needles was verified by US. RESULTS The full extent of the lumpectomy cavity was underestimated by clinical examination (physical exam, operative report, mammographic information and location of the surgical scar) in 33 of 38 patients (87%). The depth to the chest wall was also incorrectly estimated in 34 (90%) patients when compared to US examination. Intraoperatively, US was performed in nine patients and was useful in verifying the accurate placement of the deepest plane of interstitial brachytherapy needles. In 7 of 9 patients (75%), clinical placement of needles did not ensure adequate coverage of the posterior extent of the lumpectomy cavity as visualized by intraoperative US. CONCLUSIONS In breast cancer patients considered for interstitial brachytherapy, US appears to be a more accurate means of identifying the full extent of the lumpectomy cavity when compared to clinical estimates. In addition, US allows real-time verification of needle placement in the intraoperative setting.
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Vicini FA, Chen PY, Fraile M, Gustafson GS, Edmundson GK, Jaffray DA, Benitez P, Pettinga J, Madrazo B, Ingold JA, Goldstein NS, Matter RC, Martinez AA. Low-dose-rate brachytherapy as the sole radiation modality in the management of patients with early-stage breast cancer treated with breast-conserving therapy: preliminary results of a pilot trial. Int J Radiat Oncol Biol Phys 1997; 38:301-10. [PMID: 9226316 DOI: 10.1016/s0360-3016(97)00035-7] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE We present the preliminary findings of our in-house protocol treating the tumor bed alone after lumpectomy with low-dose-rate (LDR) interstitial brachytherapy in selected patients with early-stage breast cancer treated with breast-conserving therapy (BCT). METHODS AND MATERIALS Since March 1, 1993, 60 women with early-stage breast cancer were entered into a protocol of tumor bed irradiation only using an interstitial LDR implant with iodine-125. Patients were eligible if the tumor was < or = 3 cm, margins were > or = 2 mm, there was no extensive intraductal component, the axilla was surgically staged, and a postoperative mammogram was performed. Implants were placed using a standardized template either at the time of reexcision or shortly after lumpectomy. A total of 50 Gy was delivered at 0.52 Gy/h over a period of 96 h to the lumpectomy bed plus a 2-cm margin. Perioperative complications, cosmetic outcome, and local control were assessed. RESULTS The median follow-up for all patients is 20 months. Three patients experienced minimal perioperative pain that required temporary nonnarcotic analgesics. There have been four postoperative infections which resolved with oral antibiotics. No significant skin reactions related to the implant were noted and no patient experienced impaired would healing. Early cosmetic results reveal minimal changes consisting of transient hyperpigmentation of the skin at the puncture sites and temporary induration in the tumor bed. Good to excellent cosmetic results were noted in all 19 patients followed up a minimum of 24 months posttherapy. To date, 51 women have obtained 6-12-month follow-up mammograms and no recurrences have been noted. All patients currently have no physical signs of recurrence, and no patient has failed regionally or distantly. CONCLUSION Treatment of the tumor bed alone with LDR interstitial brachytherapy appears to be well tolerated, and early results are promising. Long-term follow-up of these patients is necessary to establish the equivalence of this treatment approach compared to standard BCT, however.
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Tang RB, Chen SJ, Wu KK, Lee BH, Chen PY. Interferon-gamma in cerebrospinal fluid of children with aseptic meningitis. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1997; 59:248-53. [PMID: 9216121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Certain cytokines may contribute to the sequence of events that lead to meningeal inflammation in bacterial meningitis. However, their role in viral meningitis is not so less well defined. We determined the cytokines levels in the cerebrospinal fluid (CSF) of children with aseptic meningitis and discussed their relationship with clinical and laboratory findings. METHODS We determined the concentrations of interleukin-1 beta (IL-1 beta), interferon-gamma (IFN-gamma) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in the CSF of 62 patients with aseptic meningitis including 17 patients with culture-proved enteroviral meningitis, and from 19 control acute febrile patients without meningitis. RESULTS The GM-CSF in the cerebrospinal fluid was detected from one of the 62 patients with aseptic meningitis and none of the 19 controls. Fourteen (23%) of the 62 patients with aseptic meningitis and 2 (10.5%) of 19 controls had detectable IL-1 beta. There was no significant difference in IL-1 beta levels between patients with aseptic meningitis (4.4 +/- 11.4 pg/ml) and control group (2.4 +/- 7.7 pg/ml). The CSF IFN-gamma level was detectable in 40 (65%) of 62 patients and 6 (31.6%) of 19 controls. The mean CSF IFN-gamma concentration was significantly higher in patients with aseptic meningitis when compared with that in control group (37.9 +/- 48.8 pg/ml vs 17.5 +/- 29.7 pg/ml; p = 0.007). CONCLUSIONS IFN-gamma was detectable in the CSF in 65% of patients with aseptic meningitis and the role of interferon-gamma remains to be determined.
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Vicini FA, Horwitz EM, Lacerna MD, Dmuchowski CF, Brown DM, White J, Chen PY, Edmundson GK, Gustafson GS, Clarke DH, Gustafson GS, Matter RC, Martinez AA. Long-term outcome with interstitial brachytherapy in the management of patients with early-stage breast cancer treated with breast-conserving therapy. Int J Radiat Oncol Biol Phys 1997; 37:845-52. [PMID: 9128961 DOI: 10.1016/s0360-3016(96)00606-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE We reviewed our institution's experience with interstitial implant boosts to determine their long-term impact on local control and cosmetic results. METHODS AND MATERIALS Between January 1, 1980 and December 31, 1987, 390 women with 400 cases of Stage I and II breast cancer were managed with breast-conserving therapy (BCT) at William Beaumont Hospital. All patients were treated with an excisional biopsy and 253 (63%) underwent reexcision. Radiation consisted of 45-50 Gy external beam irradiation to the whole breast followed by a boost to the tumor bed to at least 60 Gy using either electrons [108], photons [15], or an interstitial implant [277] with either 192Ir [190] or 125I [87]. Long-term local control and cosmetic outcome were assessed and contrasted between patients boosted with either interstitial implants, electrons, or photons. RESULTS With a median follow-up of 81 months, 25 patients have recurred in the treated breast for a 5- and 8-year actuarial rate of local recurrence of 4 and 8%, respectively. There were no statistically significant differences in the 5- or 8-year actuarial rates of local recurrence using either electrons, photons, or an interstitial implant. Greater than 90% of patients obtained a good or excellent cosmetic result, and no statistically significant differences in cosmetic outcome were seen whether electrons, photons, or implants were used. CONCLUSIONS We conclude that patients with Stage I and II breast cancer undergoing BCT and judged to be candidates for boosts can be effectively managed with LDR interstitial brachytherapy. Long-term local control and cosmetic outcome are excellent and similar to patients boosted with either electrons or photons.
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Beron PJ, Horwitz EM, Martinez AA, Wimbish KJ, Levine AJ, Gustafson G, Chen PY, Ingold JA, Vicini FA. Pathologic and mammographic findings predicting the adequacy of tumor excision before breast-conserving therapy. AJR Am J Roentgenol 1996; 167:1409-14. [PMID: 8956568 DOI: 10.2214/ajr.167.6.8956568] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE We performed a retrospective review to determine the need for reexcision after excisional biopsy in patients with breast cancer who were treated with breast-conserving therapy. MATERIALS AND METHODS Eighty-seven patients with infiltrating ductal carcinoma of the breast underwent excisional biopsy followed by reexcision of the tumor site. Reexcision specimens were evaluated for residual disease and correlated with initial mammographic and pathologic findings. RESULTS Tumors with an extensive intraductal component (EIC) were more likely to have residual disease at reexcision than those without an EIC (65% versus 6%, p < .01). Initially positive margins did not predict residual disease at reexcision significantly better than did initially negative margins (29% versus 13%, p = .08). Suspicious mammographic calcifications, absence of a discernible mass detected mammographically, or both were associated with a significantly increased risk of residual disease at reexcision. By combining all features (EIC, margin status, and mammography), we found that subsets of patients had significantly different risks of residual disease, which ranged from 6% to 83% (p < .01). CONCLUSION Mammographic and pathologic findings are useful in predicting the adequacy of breast resection before radiation therapy in patients treated with breast-conserving therapy. An EIC is the most useful predictor of residual disease at reexcision. When combined, EIC, margin status, and mammographic findings form a powerful tool to judge the need for reexcision before radiation therapy.
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Horwitz EM, Vicini FA, Ziaja EL, Gonzalez J, Dmuchowski CF, Stromberg JS, Brabbins DS, Hollander J, Chen PY, Martinez AA. Assessing the variability of outcome for patients treated with localized prostate irradiation using different definitions of biochemical control. Int J Radiat Oncol Biol Phys 1996; 36:565-71. [PMID: 8948340 DOI: 10.1016/s0360-3016(96)00360-4] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE Biochemical control using serial posttreatment serum prostate specific antigen (PSA) levels is being increasingly used to assess treatment efficacy for localized prostate cancer. However, no standardized definition of biochemical control has been established. We reviewed our experience treating patients with localized prostate cancer and applied three different commonly used definitions of biochemical control to determine if differences in therapeutic outcome would be observed. METHODS AND MATERIALS Between January 1987 and December 1991, 480 patients with clinically localized prostate cancer received external beam irradiation (RT) using localized prostate fields at William Beaumont Hospital. The median dose to the prostate was 66.6 Gy (range 58-70.4) using a four-field or arc technique. Pretreatment and posttreatment serum PSA levels were recorded. Over 86% (414 of 480) of patients had a pretreatment PSA level available. Three different definitions of biochemical control were used: (a) PSA nadir < 1 ng/ml within 1 year of treatment completion. After achieving nadir, if two consecutive increases of PSA were noted, the patient was scored a failure at the time of the first increase; (b) PSA nadir < 1.5 ng/ml within 1 year of treatment completion. After achieving nadir, if two consecutive increases of PSA were noted, the patient was scored a failure at the time of the first increase; (c) Posttreatment PSA nadir < 4 ng/ml without a time limit. Once the nadir was achieved, if it did not rise above normal the patient was considered to be biochemically controlled. Clinical local control was defined as no palpable prostate nodularity beyond 18 months, no new prostate nodularity, or a negative prostate biopsy. RESULTS Median follow-up was 48 months (range 3-112). Pretreatment PSA values were correlated with treatment outcome using the three definitions of biochemical control as well as clinical local control. Pretreatment PSA values were stratified into five groups (Group 1: PSA < 4; Group 2: PSA 4-10; Group 3: PSA 10-15; Group 4: PSA 15-20; and Group 5: PSA > 20), and 5-year actuarial rates of biochemical control were calculated using the three biochemical control and one clinical local control definitions. For Group 1, 5-year actuarial rates of biochemical control were 84%, 90%, 91%, and 96% for Definitions 1-3 and clinical local control, respectively. For Group 2, 5-year actuarial control rates were 45%, 54%, 74%, and 92% for the four definitions, respectively. For Group 3, 5-year actuarial control rates were 26%, 31%, 63%, and 100% for the four definitions, respectively. For Group 4, 5-year actuarial control rates were 24%, 24%, 50%, and 100% for the four definitions, respectively. Finally, for Group 5, 5-year actuarial control rates were 5%, 14%, 15%, and 89% for the four definitions, respectively. Depending on the definition used, statistically significant differences overall in outcome rates were observed. Differences between all four definitions for all pairwise comparisons ranged from 5 to 53% (p < 0.001). CONCLUSION When different definitions of biochemical control are used in assessing treatment outcome, significantly different rates of success are noted. Until a standardized definition of biochemical control is adopted, differences in treatment outcome cannot be meaningfully compared.
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Chuang LC, Chen PY, Chen C, Huang TH, Wang KT, Chiou SH, Wu SH. Structural analysis of a biologically active echistatin analogue des(46-49)-[Ala8,37]-echistatin gamma with three disulfide bonds by 2D-NMR and computer graphics. Biochem Biophys Res Commun 1996; 220:246-54. [PMID: 8645291 DOI: 10.1006/bbrc.1996.0422] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
An echistatin analogue, designated as des(46-49)-[Ala8,37]-echistatin gamma, was synthesized chemically by solid-phase peptide synthesis. The analogue was made by replacing Cys8 and Cys37 residues with two alanines and the deletion of C-terminal peptide 46-49 of echistatin gamma, resulting in an artificial polypeptide of 45 amino acids with three disulfide bonds. In the platelet aggregation assay, the analogue exhibits almost the same activity as echistatin gamma, indicating that the linear sequence of des(46-49)-[Ala8,37]-echistatin gamma contains all of the primary-structure information that is required for proper folding of this synthetic polypeptide. The tertiary structure of the analogue, as determined from high-resolution nuclear magnetic resonance (NMR) coupled with dynamic simulated annealing, is very similar to that of echistatin alpha1 which differs from echistatin gamma by 8 residues. In particular the two important sites of the Arg-Gly-Asp (RGD) loop and the C-terminal Lys45, both of which show some degree of disorder, are maintained in similar spatial orientation and proximity as those in echistatin alpha 1 even without the constraint provided by the disulfide bond of the (Cys8-Cys37) pair. These results provide new insights in further defining distinct structural features of echistatin gamma, which are involved in supporting the active polypeptide conformation to achieve biological activity in the absence of one pair of disulfide bonds.
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Liu TZ, Chen PY, Chiu DT, Wei JS, Chang KS, Lin KH. Detection of a novel lactate dehydrogenase isozyme and an apparent differentiation-associated shift in isozyme profile in hepatoma cell lines. Cancer Lett 1994; 87:193-8. [PMID: 7812940 DOI: 10.1016/0304-3835(94)90222-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A hitherto unreported lactate dehydrogenase (LD) isoenzyme, which migrates electrophoretically to the relative position between LD2 and LD3 has been identified in the electropheratogram in 7 of 7 (100%) cultured hepatoma cell lines with various degrees of differentiation and is thus given the name LD2-3. LD2-3 seems to be specific for hepatoma cells because this atypical isoenzyme can not be detected in other tumor cell lines. In addition, the hepatoma cell lines also show a distinct pattern of LD isoenzyme and the isoenzyme pattern varies with the degree of differentiation. Hence, the expression pattern of LD isoenzyme phenotypes may provide a good marker for the investigation of human hepatoma cell differentiation.
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Chen PY, Chu HY, Shian WJ, Shu SG, Chi CS. Varicella-zoster virus infection in children with malignancy. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1994; 54:417-23. [PMID: 7850684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Immunocompromised children are potentially threatened by infections, among which, the highly contagious chickenpox infection is the most common. In the past six months, there has been a spate of five chickenpox infections in children with malignancy, all of whom were receiving chemotherapy at that time. METHODS The cases of 17 children with malignancies, who suffered from varicella-zoster infection during a period of chemotherapy at Taichung Veterans General Hospital were reviewed. RESULTS The diagnoses of their neoplasms were 12 acute lymphoblastic leukemia (ALL), 2 lymphoma, 3 solid tumors. The mean age was 6.8 +/- 4.0 year-old (range 3 to 15 year-old). The average duration from chickenpox skin eruption to admission was 3.3 +/- 1.8 days. Four patients suffered from abdominal pain and three of them died soon; three of them suffered from back pain and one died later. Seven of these 11 patients had impaired liver function (GOT > 45 U/L), of whom 4 died later. There were seven patients with pneumonitis, of whom five died later. Among 12 patients with ALL, 3 had absolute lymphocyte counts (ALC) < 500/mm3, but only 1 died later; 9 had ALC > 500/mm3, of whom 4 had pneumonitis, and all died later. Four patients developed disseminated intravascular coagulopathy, and three of them died later. Seven patients were prescribed acyclovir within three days after first skin eruption, none of these died. Ten patients were prescribed acyclovir three days or more after first skin eruption and five of them died later. Five patients were prescribed intravenous immunoglobulin (IVIG) within three days after first skin eruption, and none of them died; of the seven patients prescribed IVIG three days or more after first skin eruption, three died later. CONCLUSIONS Abdominal pain and disseminated intravascular coagulopathy (DIC) were signs of visceral dissemination. Severe liver function impairment, pneumonitis and DIC were the principal causes of death. Early administration of acyclovir and intravenous immunoglobulin (IVIG) can probably effectively prevent the dissemination of varicella-zoster virus (VZV). While varicella-zoster immunoglobulin (VZIG) was unavailable, IVIG was still valuable in treating VZV infection.
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Wu JS, Lee HF, Hsiau HL, Lu HY, Chou WH, Lu CF, Chen HY, Lee FN, Chen PY, Tam KM. Genotype distribution of hepatitis C virus infection in Taiwan. J Med Virol 1994; 44:74-9. [PMID: 7798889 DOI: 10.1002/jmv.1890440114] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
To investigate the prevalence of genotype distribution of hepatitis C virus (HCV) infection in Taiwan, genotypes were identified in 122 (36 anti-HCV-positive blood donors, 44 anti-HCV-positive aborigines, 28 hemodialysis patients, and 14 patients with chronic liver diseases) of 280 subjects, using polymerase chain reaction by Okamoto's type-specific primer method. Type II was the dominant (66.7%) type among anti-HCV-positive blood donors, followed by type III and type IV with the same percentages (16.7%), while none of type I was detected. The prevalence of genotype distribution were 75.0%, 81.1%, and 64.3% for type II, 4.6%, 17.9%, and 21.4% for type III, 13.6%, 0%, and 7.1% for type IV, for the aborigines, hemodialysis, and chronic liver diseases groups, respectively. Four subjects revealed mixed infections by two different genotypes: two cases of II and III; and each one case of II and IV, and III and IV. Diverse genotype distributions in two hemodialysis groups disclose the existence of obvious regional differences even within a region. The results reveal the highest prevalence of type II as in Japan. However, there is a higher prevalence rate of type IV than in Japan.
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Chen PY, Wu SH, Wang KT. Chemical synthesis of gamma-echistatin analogues: elucidation of status of C-terminal (45-49). PROTEIN ENGINEERING 1994; 7:941-4. [PMID: 7971956 DOI: 10.1093/protein/7.7.941] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Three analogues of gamma-echistatin, des(45-49)-gamma-echistatin, des(46-49)-gamma-echistatin and des(47-49)-gamma-echistatin, were synthesized by solid-phase methodology and their biological activities were measured and compared. The results reveal that without the C-terminal (45-49) of gamma-echistatin, the folding of the protein to the final active structure is not interfered with and Lys-45 influences the inhibition of platelet aggregation.
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Chang C, Chen LH, Chen PY. Developmental stages of Chinese children's concepts of health and illness in Taiwan. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI ZA ZHI [JOURNAL]. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI 1994; 35:27-35. [PMID: 8178640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This research showed that conceptual development of health and illness of Chinese children in Taiwan follows the general pattern of Piaget's levels of development. But Reichenbach's hypotheses of social influence explained the incongruencies in the data. Questionnaire and unstructured interview were used to explore the conceptual development of 468 children who were grouped according to their educational level: kindergarten, first and second grades, third and fourth grades, as well as fifth and sixth grades. Results showed that children in general defined illness and health based on physiological dysfunction. The older school children attributed "inappropriate behaviors" as the cause of illness more than young school children did. Nearly a quarter of the kindergarten group appeared to be at Piaget's level of "phenomenism" when asked to explain the cause of illness. Children also relied on "external resources" as the method to treat illness; younger school children emphasized "medicine treatment". In addition, all children believed "appropriate behaviors" can promote health, but awareness of psychological health did not appear until third and fourth grades.
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Armour EP, Wang Z, Corry PM, Chen PY, Martinez A. Hyperthermic enhancement of high dose-rate irradiation in 9L gliosarcoma cells. Int J Radiat Oncol Biol Phys 1994; 28:171-7. [PMID: 8270439 DOI: 10.1016/0360-3016(94)90155-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
PURPOSE Long duration-mild temperature hyperthermia has previously been shown to be an effective potentiator of low-dose-rate irradiation. An in vitro investigation was initiated to determine if 41 degrees C hyperthermia could be useful in sensitizing high-dose-rate (HDR) brachytherapy. Experiments were designed to determine the optimal length of heat treatments to be applied with a twice daily 5 Gy times five fraction high-dose-rate protocol. METHODS AND MATERIALS Rat 9L gliosarcoma cells growing exponentially in flasks were exposed to X-irradiation and 41 degrees C hyperthermia. Irradiation was applied in 5 Gy fractions two times per day to a total dose of 25 Gy. Hyperthermia consisted of combinations of 1 or 4 hr heating before and/or after each of the radiation exposures. In addition, a set of cells was heated continuously at 41 degrees C starting 6 hr before the first fraction and continuing to 4 hr after the 5th fraction. Cell survival was assayed by colony formation. RESULTS Sensitization of high-dose-rate increased linearly with increasing length of 41 degrees C heating over the entire range of heat exposures applied. Maximum sensitization was produced by continuous heating for 58 hr throughout the entire radiation course. Heating for 4 hr before fractions two through five produced less sensitization to these later fractions than was expected if each heat-radiation fraction had acted independent of the other fractions. CONCLUSION Continuous 41 degrees C heating eliminated split dose sparing during high-dose-rate. The apparent development of thermotolerance during the course of heat and high-dose-rate resulted in reduced sensitization in the later fractions when 4 hr pre- and/or post-heat were applied. This tolerance was overcome if heat was applied continuously between radiation fractions. The clinical relevance of these in vitro data is that 41 degrees C hyperthermia should be applied for as long as is possible during this type of high-dose-rate protocol. This combined hyperthermia-high-dose-rate treatment may enhance the efficacy of interstitial irradiation in situations such as boost irradiation of high grade glioma.
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Chen PY, Sanders PW. Role of nitric oxide synthesis in salt-sensitive hypertension in Dahl/Rapp rats. Hypertension 1993; 22:812-8. [PMID: 7503951 DOI: 10.1161/01.hyp.22.6.812] [Citation(s) in RCA: 164] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Nitric oxide is a potent endogenous vasodilator that regulates arterial tone. A family of nitric oxide synthases uses L-arginine and L-homoarginine stereospecifically as substrates for nitric oxide production in vivo. By preventing expression of inducible but not constitutive nitric oxide synthases, glucocorticoids differentiate which enzyme in this family is the predominant source of nitric oxide generation in a given situation. We proposed that defective production of nitric oxide produces salt-sensitive hypertension in the Dahl/Rapp rat. Plasma concentrations of L-arginine, citrulline, and ornithine of salt-sensitive (SS/Jr) and salt-resistant (SR/Jr) rats on 8% sodium chloride chow for 1 week did not differ. However, intravenous infusion of L-arginine and L-homoarginine, but not D-arginine, increased urinary excretion of nitrate, the degradation product of nitric oxide, and simultaneously lowered blood pressure in hypertensive SS/Jr rats. Oral L-arginine also prevented development of hypertension and increased urinary excretion of cyclic GMP and nitrate in these rats. Dexamethasone, in a dose that prevented hypotension from parenteral injection of lipopolysaccharide, completely prevented the increase in excretion of cyclic GMP and nitrate, and hypertension resulted despite concomitant treatment with L-arginine. These studies supported an important role of dexamethasone-suppressible nitric oxide synthesis in the prevention of salt-sensitive hypertension in the Dahl/Rapp rat.
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Chen PY, St John PL, Kirk KA, Abrahamson DR, Sanders PW. Hypertensive nephrosclerosis in the Dahl/Rapp rat. Initial sites of injury and effect of dietary L-arginine supplementation. J Transl Med 1993; 68:174-84. [PMID: 8441251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND The Dahl/Rapp strains of salt-sensitive (SS/Jr) and salt-resistant (SR/Jr) rat were developed to examine pathogenetic mechanisms that produce hypertension in response to an increase in dietary salt. We have shown that providing SS/Jr rats with L-arginine, the metabolic precursor of nitric oxide, acutely prevented salt-sensitive hypertension, suggesting that SS/Jr rats developed hypertension because of inadequate nitric oxide production while on a high-salt diet. EXPERIMENTAL DESIGN Male 23-day SS/Jr and SR/Jr rats were placed on chow that contained 8% sodium chloride. One group of SS/Jr rats also received L-arginine, 1.25 g/liter, in their drinking water. These three groups were examined at weekly intervals for 4 weeks. RESULTS SS/Jr rats rapidly developed hypertension when placed on the high-salt chow. After 2 weeks on this diet, inulin clearance dramatically decreased, and albumin excretion rate increased. By the fourth week of study, SS/Jr rats on the high-salt diet had died or were dying. Coincident with the progressive decline in inulin clearance, renal morphologic analysis confirmed development of myointimal thickening, fibrinoid necrosis, and glomerulosclerosis. In contrast, over the 4 weeks of study, SS/Jr rats supplemented with oral L-arginine did not develop hypertension and any of the associated renal complications seen in age-matched SS/Jr rats on the high-salt diet. L-Arginine also corrected hypertension in SS/Jr rats exposed to the high-salt chow for 2 weeks before the inception of L-arginine. L-Arginine administration after 3 weeks on this chow, however, failed to reverse hypertension and the depressed inulin clearance and morphologic renal damage. CONCLUSIONS Along with previous work (Chen PY, Sanders PW, J Clin Invest 88:1559-67), these studies were consistent with the hypothesis that hypertension and hypertensive nephrosclerosis developed in SS/Jr rats because, while on a high-salt diet, substrate (L-arginine) became a rate-limiting factor in the synthesis of nitric oxide.
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Chen PY, Tsai MC. Renal basolateral membrane SO4/HCO3 transporter characterized by fluorescent acridine orange. NIHON JINZO GAKKAI SHI 1992; 34:331-5. [PMID: 1635277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Acridine orange (AO), a pH-sensitive fluorescent indicator, was used to study the characteristics of SO4/HCO3 transport in basolateral membrane vesicles (BLMV) isolated from rabbit renal cortex. The BLMV preparation containing a low buffer concentration and preloaded with 25 mM HCO3 was mixed with buffer containing AO and SO4 in the absence of an initial pH gradient. SO4 influx tended to drive HCO3 efflux, causing intravesicular accumulation of AO and fluorescence quenching. There was no AO quenching in the absence of HCO3 with or without an external SO4 gradient. 100 microM 4,4'-dibenzamido-2,2'-disulfonic stilbene (DBDS) inhibited the fluorescence quenching completely. 25 and 100 mM external Cl did not cause AO quenching. There was no effect of pH (6.5-8.0) on SO4/HCO3 transport. The Kd for SO4 was 8.2 mM. A positive inwardly directed diffusion potential (K(in) = 5 mM, K(out) = 100 mM with valinomycin) did not exert any effect on the SO4/HCO3 transport, indicating that the transport process is insensitive to voltage. The Ki for DBDS inhibition of SO4/HCO3 transport was 2.3 microM.
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Chen SH, Chen PY, Pan S, Lien GS, Yang IF, Huang TS. Acute esophageal ulcer with massive bleeding: an unusual complication of uremic patient during hemodialysis. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1991; 48:477-80. [PMID: 1664288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Inflammatory mucosal changes of upper gastrointestinal (GI) tract including stomach and duodenum are well documented in uremic patients and assumed to be the major source of upper GI bleeding. However, acute esophageal ulcer which causes massive bleeding on hemodialysis is rare. Herewith a case is reported. A 28-year-old male uremic patient had a sudden onset of hematemesis on hemodialysis. Urgent endoscopy revealed an acute mucosal lesion with bleeding at the upper and middle third esophagus. It was demonstrated by esophageal biopsy. The patient had taken some pepper one day before and was choked during hemodialysis. This special condition is suggested to induce the acute esophageal ulcer and bleeding.
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Chen PY, Sanders PW. L-arginine abrogates salt-sensitive hypertension in Dahl/Rapp rats. J Clin Invest 1991; 88:1559-67. [PMID: 1658045 PMCID: PMC295672 DOI: 10.1172/jci115467] [Citation(s) in RCA: 329] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
This study examined the contribution of nitric oxide (NO) to the susceptibility or resistance to the hypertensive effects of high sodium chloride (8.0% NaCl) intake in young Dahl/Rapp salt-sensitive (SS/Jr) and salt-resistant (SR/Jr) rats. Using NG-monomethyl-L-arginine (L-NMMA) as a probe for NO production in vivo, we found that increasing dietary sodium chloride increased NO activity in salt-resistant rats, but not in salt-sensitive rats. Exogenous L-arginine, the substrate for NO synthesis, decreased blood pressure to normotensive levels in salt-sensitive rats made hypertensive for 2 wk from 8.0% NaCl chow. D-arginine had no effect on blood pressure of these rats and L-arginine did not change blood pressure of salt-resistant rats. Intraperitoneal injections of L-arginine and its precursor, L-citrulline, and oral L-arginine, but not D-arginine, prevented the increase in blood pressure in salt-sensitive rats on the high salt chow over 2 wk of observation. In contrast, L-arginine did not alter the development of hypertension in spontaneously hypertensive rats. Mean urinary cGMP levels were higher in salt-sensitive rats on oral L-arginine than salt-sensitive rats on D-arginine. Infusion of L-NMMA acutely decreased, whereas intravenous L-arginine rapidly increased, urinary cGMP in both groups. L-arginine and L-citrulline increased production of NO and prevented salt-sensitive hypertension in Dahl/Rapp rats.
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139
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Chen PY, Spector PE. Negative affectivity as the underlying cause of correlations between stressors and strains. JOURNAL OF APPLIED PSYCHOLOGY 1991; 76:398-407. [PMID: 1864813 DOI: 10.1037/0021-9010.76.3.398] [Citation(s) in RCA: 185] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The extent to which negative affectivity (NA), the tendency to experience a wide range of negative emotions, inflated correlations between chronic job stressors and strains was examined in this study. NA was found to account for a large proportion of shared variance between stressors and physical strains (as indicated by absence, doctor visits, and physical symptoms). Contrary to the results of Brief, Burke, George, Robinson, and Webster (1988), NA did not account for much of the variance shared by stressors and affective strains (job satisfaction, anger, and feelings of stress and frustration). Reasons for the failure of this and several earlier studies to successfully replicate Brief et al.'s results are explored.
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140
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Yuan ZY, Li SY, Li X, Chen PY, Wang Y, Wu XF. Microencapsulation of DNA-recombinant cells and its application in production of HBsAg. Ann N Y Acad Sci 1990; 613:338-46. [PMID: 2075975 DOI: 10.1111/j.1749-6632.1990.tb18175.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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141
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Chen PY, Pearce D, Verkman AS. Membrane water and solute permeability determined quantitatively by self-quenching of an entrapped fluorophore. Biochemistry 1988; 27:5713-8. [PMID: 3179272 DOI: 10.1021/bi00415a048] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Quantitative determination of rapid water and solute transport and solute reflection coefficients by light-scattering methods is complicated by dependence of vesicle or cell light scattering on nonvolume factors including solution refractive index, cell motion, and membrane aggregation. To overcome these difficulties, a fluorescence technique has been developed to measure accurately (1) osmotic water permeability (Pf), (2) solute permeability (Ps), and (3) solute reflection coefficient (sigma). The time course of vesicle volume is determined by the self-quenching of entrapped fluorescein sulfonate (FS), the best of a series of dyes screened for self-quenching, brightness, and vesicle loading/trapping. To validate the method, rabbit renal brush border vesicles (BBV) were loaded with 1-10 mM FS for 12 h at 4 degrees C and washed to remove extravesicular FS. FS leakage occurred over greater than 6 h at 4 degrees C and greater than 30 min at 23 degrees C. FS fluorescence vs vesicle volume was calibrated from the time course of fluorescence decrease (excitation 470 nm, emission greater than 515 nm) in response to a series of inward osmotic gradients in a stopped-flow apparatus. At 23 degrees C Pf was 0.005 +/- 0.001 cm/s, independent of osmotic gradient size, and inhibited 67% by 0.5 mM HgCl2. Urea Ps was 2 x 10(-6) cm/s with sigma 0.95-1.00 on the basis of the fluorescence time course analysis and the extravesicular [urea] required to obtain zero initial volume flow (null method) when vesicles were loaded with sucrose.(ABSTRACT TRUNCATED AT 250 WORDS)
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Chen PY, Verkman AS. Sodium-dependent chloride transport in basolateral membrane vesicles isolated from rabbit proximal tubule. Biochemistry 1988; 27:655-60. [PMID: 3349054 DOI: 10.1021/bi00402a024] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The mechanisms for Cl transport across basolateral membrane vesicles (BLMV) isolated from rabbit renal cortex were examined by using the Cl-sensitive fluorescent indicator 6-methoxy-N-(3-sulfopropyl)quinolinium (SPQ). The transporters studied included Cl/base exchange, Cl/base/Na cotransport, K/Cl cotransport, and Cl conductance. Initial rates of chloride influx (JCl) were determined from the measured time course of SPQ fluorescence in BLMV following inwardly directed gradients of Cl and gradients of other ions and/or pH. For a 50 mM inwardly directed Cl gradient in BLMV which were voltage and pH clamped (7.0) using K/valinomycin and nigericin, JCl was 0.80 +/- 0.14 nmol S-1 (mg of vesicle protein)-1 (mean +/- SD, n = 8 separate preparations). In the absence of Na and CO2/HCO3 in voltage-clamped BLMV, JCl increased 56% +/- 5% in response to a 1.9 pH unit inwardly directed H gradient; the increase was further enhanced by 40% +/- 3% in the presence of CO2/HCO3 and inhibited 30% +/- 8% by 100 microM dihydro-4,4'-diisothiocyanostilbene-2,2'-disulfonic acid. Na gradients did not increase JCl in the absence of CO2/HCO3; however, an outwardly directed Na gradient in the presence of CO2/HCO3 increased JCl by 31% +/- 8% with a Na KD of 7 +/- 2 mM. These results indicate the presence of Cl/OH and Cl/HCO3 exchange, and Cl/HCO3 exchange trans-stimulated by Na. There was no significant effect of K gradients in the presence or absence of valinomycin, suggesting lack of significant K/Cl cotransport and Cl conductance under experimental conditions.(ABSTRACT TRUNCATED AT 250 WORDS)
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143
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Chen PY, Illsley NP, Verkman AS. Renal brush-border chloride transport mechanisms characterized using a fluorescent indicator. THE AMERICAN JOURNAL OF PHYSIOLOGY 1988; 254:F114-20. [PMID: 3337241 DOI: 10.1152/ajprenal.1988.254.1.f114] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Cl transport mechanisms in brush-border membrane vesicles (BBMV) isolated from rabbit renal cortex were characterized using the Cl-sensitive fluorescent indicator 6-methoxy-N-[3-sulfopropyl]quinolinium (SPQ). In control experiments using 36Cl, SPQ did not itself alter rates for Cl transport. Cl fluxes (JCl) in nanomoles per second per milligram vesicle protein in response to gradients of Cl and other ions were calculated from the SPQ fluorescence time course, fluorescence vs. [Cl] calibration, and BBMV glucose space (microliter/mg protein). For a 50 mM inwardly directed Cl gradient in BBMV (voltage and pH clamped) JCl was 0.26 +/- 0.01 nmol.s-1.mg-1 (mean +/- SD, 4 vesicle preparations). JCl was not altered by a 50 mM inwardly directed Na gradient (0.25 +/- 0.01 nmol.s-1.mg-1) but increased to 0.52 +/- 0.04 nmol.s-1.mg-1 when driven by a 1.5 pH unit inwardly directed proton gradient. The pH driven increase in JCl was blocked by H2DIDS (100 microM, JCl = 0.38 +/- 0.02 nmol.s-1.mg-1). In the absence of a gradient, JCl increased by 64 +/- 4% in the presence of 1 mM formate on both sides of the membrane; the increase was blocked by H2DIDS. JCl increased to 0.38 +/- 0.02 nmol.s-1.mg-1 for a 60-mV K valinomycin diffusion potential (internal positive); the increase was inhibited by the Cl channel blocker diphenylamine-2-carboxylate (DPC, 100 microM, JCl = 0.26 +/- 0.03 nmol.s-1.mg-1). Br and I transport was also blocked by DPC.(ABSTRACT TRUNCATED AT 250 WORDS)
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Chen PY, Verkman AS. Renal basolateral membrane anion transporter characterized by a fluorescent disulfonic stilbene. J Membr Biol 1987; 100:1-12. [PMID: 2448466 DOI: 10.1007/bf02209135] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The fluorescence enhancement of 4,4'-dibenzamido-2,2'-disulfonic stilbene (DBDS) upon binding to membranes was used to examine proximal tubule stilbene binding sites. Equilibrium binding studies of DBDS to renal brush border (BBMV) and basolateral membrane vesicles (BLMV) were performed using a fluorescence enhancement technique developed for red blood cells (A.S. Verkman, J.A. Dix and A.K. Solomon, J. Gen. Physiol. 81:421-449, 1983). In the absence of transportable anions, DBDS bound reversibly to a single class of sites on BLMV isolated from rabbit (Kd = 3.8 microM) and rat (3.2 microM); 100 microM dihydro-4,4'-diisothiocyano-2,2'-disulfonic stilbene (H2DIDS) blocked greater than 95% of binding. H2DIDS inhibitable DBDS binding was not detected using rat or rabbit BBMV. In rabbit BLMV, DBDS Kd doubled with 10 mM SO4, 50 mM HCO3 and 100 mM Cl, but was not altered by Na or pH (6-8). In stopped-flow experiments the exponential time constant for DBDS binding slowed with SO4, HCO3 and Cl, but was unaffected by Na. These results are consistent with competitive binding of DBDS and anions at an anion transport site. To relate DBDS binding data to anion transport inhibition we used 35SO4 uptake to characterize several modes of rabbit BLM anion transport: H/SO4 and Na/SO4 cotransport, and Cl/SO4 countertransport. Each transport process was electroneutral and was inhibited by H2DIDS, furosemide, probenecid, chlorothiazide and DBDS. The apparent KI's for DBDS (3-20 microM) were similar to Kd for DBDS binding. These studies define a class of anion transport sites on the proximal tubule basolateral membrane measurable optically by a fluorescent stilbene.
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Chen PY, Cui Z, Lee LF, Witter RL. Serologic differences among nondefective reticuloendotheliosis viruses. Arch Virol 1987; 93:233-45. [PMID: 3030238 DOI: 10.1007/bf01310977] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Antigenic relationships among 26 isolates of reticuloendotheliosis virus (REV) obtained from several avian species were compared by cross neutralization tests with polyclonal chicken sera and by immunofluorescent assays with monoclonal antibodies to REV strain T. The isolates were all strongly related by neutralization assays and thus probably constitute a single serotype. However, 3 antigenic subtypes were suggested by minor but distinct differences in neutralization titers. The validity of these 3 subtype designations was confirmed by differential reactivity of viral isolates to selected monoclonal antibodies. Subtype-associated differences in serum antibody titers were noted following the inoculation of chickens with the REV isolates.
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146
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Chen PY, Verkman AS. Non-electrolyte transport across renal proximal tubule cell membranes measured by tracer efflux and light scattering. Pflugers Arch 1987; 408:491-6. [PMID: 3110738 DOI: 10.1007/bf00585074] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Non-electrolyte transport in brush border membrane vesicles (BBMV), basolateral membrane vesicles (BLMV) and in viable cells isolated from the proximal convoluted tubule (PCT) of the rabbit kidney were measured by rapid filtration and stopped-flow light scattering techniques. Efflux of tracer solute was measured by loading packed vesicles or cells with 14C solute, diluting into nonradioactive buffer and filtering rapidly at varying incubation times. In BBMV at 23 degrees C, [14C-urea] decreased exponentially with time constant 3.2 +/- 0.3 s (S.D., n = 5) corresponding to a permeability coefficient (Purea) of 1.6 X 10(-6) cm/s, assuming a BBMV surface-to-volume ratio of 2 X 10(5) cm-1. Purea decreased to 7 X 10(-7) cm/s in the presence of 20 mM phenylurea. Tracer efflux determinations of BBMV Purea (1.6 X 10(-6) cm/s) and Pglycerol (0.6 X 10(-6) cm/s), and BLMV Purea (1.8 X 10(-6) cm/s) and Pthiourea (2.5 X 10(-6) cm/s) were in excellent agreement with Ps values determined by stopped-flow light scattering, where the time course of vesicle volume (linearly related to scattered light intensity) was measured in response to 100 mM outwardly directed solute gradients. These results establish accurate Ps value in brush border and basolateral membranes and support the application of light scattering to measure Ps in vesicles. In PCT cells however, there were systematic differences in urea and thiourea transport measured by tracer efflux and light scattering, indicating the potential difficulties in applying light scattering to Ps measurements in complex cell systems.
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Ives HE, Chen PY, Verkman AS. Mechanism of coupling between Cl- and OH- transport in renal brush-border membranes. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 863:91-100. [PMID: 3778914 DOI: 10.1016/0005-2736(86)90390-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The coupling mechanism for Cl- and H+/OH- transport in renal brush-border vesicles was examined from intravesicular pH changes following imposed H+ and Cl- gradients. Vesicles were loaded with 6-carboxyfluorescein and exposed to H+ gradients and Cl-, gluconate, or sulfate gradients, each with and without a K+/valinomycin voltage clamp. Parallel experiments were performed with vesicles equilibrated with 10 mM HCO3- or 5 mM formate. Rate of H+/OH- transport was determined from the initial rate of change in 6-carboxyfluorescein fluorescence, vesicle buffer capacity and the relationship between fluorescence and vesicle pH. In contrast to gluconate or sulfate, Cl- caused enhanced H+/OH- transport under all conditions. This difference was eliminated with voltage clamping in the presence of gluconate, SO4(2-), or HCO3-, but not in the presence of formate. These findings were not affected by the method of preparation of the vesicles. Electrically coupled Cl-/OH- transport was not inhibited by 100 microM DIDS (4,4'-diisothiocyanostilbene-2,2'-disulfonate) or 100 microM DBDS (4,4'-dibenzamidostilbene-2,2'-disulfonate). SITS (4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonate) was found to be a protonophore at concentrations greater than 500 microM. As a control for the method, we demonstrated amiloride inhibitable, electroneutral Na+-H+ exchange (H+ flux = 107 +/- 9 nmol/s per mg, 100 mM Na+) and electroneutral, DBDS inhibitable Cl(-)-HCO3- exchange in sealed human red blood cell ghosts. Therefore, electroneutral Cl(-)-OH- or HCO3- exchange does not measurably contribute to Cl- transport in the proximal tubule brush border. Cl(-)-formate exchange with formic acid recycling appears to be the only electroneutral coupling mechanism between Cl- and OH- transport demonstrable in renal brush-border membrane vesicles.
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Chen PQ, Huang TL, Chen PY, Chen H. Anterior cervical spinal surgery. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1982; 81:253-61. [PMID: 6954250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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150
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Yeh SJ, Chen PY, Ke CN, Hsu ST, Tanaka S. Neutron activation analysis for trace elements in unpolished rice. Anal Chim Acta 1976; 87:119-24. [PMID: 1008250 DOI: 10.1016/s0003-2670(01)83127-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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