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Agarwal A, Cho CL, Majzoub A, Esteves SC. Development of targeted therapeutic strategies and refinement of sperm DNA fragmentation testing. Transl Androl Urol 2017; 6:S610-S612. [PMID: 29082962 PMCID: PMC5643690 DOI: 10.21037/tau.2017.03.89] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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Agarwal A, Cho CL, Majzoub A, Esteves SC. The Society for Translational Medicine: clinical practice guidelines for sperm DNA fragmentation testing in male infertility. Transl Androl Urol 2017; 6:S720-S733. [PMID: 29082206 PMCID: PMC5643607 DOI: 10.21037/tau.2017.08.06] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sperm DNA fragmentation (SDF) testing has been emerging as a valuable tool for male fertility evaluation. While the essential role of sperm DNA integrity in human reproduction was extensively studied, the clinical indication of SDF testing is less clear. This clinical practice guideline provides recommendations of clinical utility of the test supported by evidence. It is intended to serve as a reference for fertility specialists in identifying the circumstances in which SDF testing should be of greatest clinical value. SDF testing is recommended in patients with clinical varicocele and borderline to normal semen parameters as it can better select varicocelectomy candidates. Outcomes of natural pregnancy and assisted reproductive techniques (ART) can be predicted by result of SDF tests. High SDF is also linked with recurrent pregnancy loss (RPL) and failure of ART. Result of SDF testing may change the management decision by selecting the most appropriate ART with the highest success rate for infertile couples. Several studies have demonstrated the benefit in using testicular instead of ejaculated sperm in men with high SDF, oligozoospermia or recurrent in vitro fertilization (IVF) failure. Infertile men with modifiable lifestyle factor may benefit from SDF testing by reinforcing risk factor modification and monitoring patient's progress to intervention.
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Agarwal A, Cho CL, Majzoub A, Esteves SC. Call for wider application of sperm DNA fragmentation test. Transl Androl Urol 2017; 6:S399-S401. [PMID: 29082937 PMCID: PMC5643632 DOI: 10.21037/tau.2017.03.64] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Agarwal A, Cho CL, Majzoub A, Esteves SC. Sperm DNA fragmentation testing is the safe and economical way to go. Transl Androl Urol 2017; 6:S446-S447. [PMID: 29082936 PMCID: PMC5643623 DOI: 10.21037/tau.2017.03.94] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Agarwal A, Cho CL, Majzoub A, Esteves S. Expanding treatment paradigm of high sperm DNA fragmentation. Transl Androl Urol 2017; 6:S450-S452. [PMID: 29082929 PMCID: PMC5643622 DOI: 10.21037/tau.2017.03.72] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Roychoudhury S, Agarwal A, Virk G, Cho CL. Potential role of green tea catechins in the management of oxidative stress-associated infertility. Reprod Biomed Online 2017; 34:487-498. [DOI: 10.1016/j.rbmo.2017.02.006] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 01/27/2017] [Accepted: 02/03/2017] [Indexed: 12/25/2022]
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Cho CL, Chan WK, Chu RW, Law IC. Extraluminal location of a Foley catheter balloon. Hong Kong Med J 2017; 23:207.e1-2. [PMID: 28387205 DOI: 10.12809/hkmj164938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Cho CL, Leung CLH, Chan WKW, Chu RWH, Law IC. Novel technique in the management of large prostate and bladder stones with bipolar transurethral enucleation of the prostate and open cystolithotomy. SURGICAL PRACTICE 2016. [DOI: 10.1111/1744-1633.12213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Agarwal A, Roychoudhury S, Bjugstad KB, Cho CL. Oxidation-reduction potential of semen: what is its role in the treatment of male infertility? Ther Adv Urol 2016; 8:302-318. [PMID: 27695529 PMCID: PMC5004233 DOI: 10.1177/1756287216652779] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The diagnosis of male infertility relies largely on conventional semen analysis, and its interpretation has a profound influence on subsequent management of patients. Despite poor correlation between conventional semen parameters and male fertility potential, inclusion of advanced semen quality tests to routine male infertility workup algorithms has not been widely accepted. Oxidative stress is one of the major mediators in various etiologies of male infertility; it has deleterious effects on spermatozoa, including DNA damage. Alleviation of oxidative stress constitutes a potential treatment strategy for male infertility. Measurement of seminal oxidative stress is of crucial role in the identification and monitoring of patients who may benefit from treatments. Various tests including reactive oxygen species (ROS) assay, total antioxidant capacity (TAC) assay or malondialdehyde (MDA) assay used by different laboratories have their own drawbacks. Oxidation-reduction potential (ORP) is a measure of overall balance between oxidants and antioxidants, providing a comprehensive measure of oxidative stress. The MiOXSYS™ System is a novel technology based on a galvanostatic measure of electrons; it presents static ORP (sORP) measures with static referring to the passive or current state of activity between oxidants and antioxidants. Preliminary studies have correlated sORP to poor semen qualities. It is potentially useful in prognostication of assisted reproductive techniques outcomes, screening of antioxidants either in vivo or during IVF cycles, identification of infertile men who may benefit from treatment of oxidative stress, and monitoring of treatment success. The simplified laboratory test requiring a small amount of semen would facilitate clinical application and research in the field. In this paper, we discuss the measurement of ORP by the MiOXSYS System as a real-time assessment of seminal oxidative stress, and argue that it is a potential valuable clinical test that should be incorporated into the male infertility workup and become an important guide to the treatment of oxidative stress-induced male infertility.
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Cho CL, Leung CLH, Chan WKW, Chu RWH, Law IC. Authors' reply. Hong Kong Med J 2016; 22:188-189. [PMID: 27101867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023] Open
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Cho CL, Esteves SC, Agarwal A. Novel insights into the pathophysiology of varicocele and its association with reactive oxygen species and sperm DNA fragmentation. Asian J Androl 2016; 18:186-93. [PMID: 26732105 PMCID: PMC4770484 DOI: 10.4103/1008-682x.170441] [Citation(s) in RCA: 141] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Varicocele has been associated with reduced male reproductive potential. With the advances in biomolecular techniques, it has been possible to better understand the mechanisms involved in testicular damage provoked by varicocele. Current evidence suggests the central role of reactive oxygen species (ROS) and the resultant oxidative stress (OS) in the pathogenesis of varicocele-associated male subfertility although the mechanisms have not yet been fully described and it is likely to be multifactorial. Excessive ROS is associated with sperm DNA fragmentation, which may mediate the clinical manifestation of poor sperm function and fertilization outcome related to varicocele. Testing of ROS/OS and DNA fragmentation has the potential to provide additional diagnostic and prognostic information compared to conventional semen analysis and may guide therapeutic management strategies in individual patient.
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Cho CL, Leung CLH, Chan WKW, Chu RWH, Law IC. Early postoperative outcome of bipolar transurethral enucleation and resection of the prostate. Hong Kong Med J 2015; 21:528-35. [PMID: 26492836 DOI: 10.12809/hkmj144457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To report the early postoperative outcome of bipolar transurethral enucleation and resection of the prostate. Our results were compared with those published from various centres. SETTING Regional hospital, Hong Kong. PATIENTS A total of 28 consecutive patients who had undergone bipolar transurethral enucleation and resection of the prostate by a single surgeon between January and June 2014. All patients were evaluated preoperatively by physical examination, digital rectal examination, transrectal ultrasonography, and laboratory studies, including measurement of haemoglobin, sodium, and prostate-specific antigen levels. Patients were assessed perioperatively and at 4 weeks and 3 months postoperatively. RESULTS The mean resected specimen weight of prostatic adenoma in 28 patients was 48.2 g with a mean enucleation and resection time of 13.6 and 47.7 minutes, respectively. There was a mean decrease in serum prostate-specific antigen by 85.9% (from 6.4 ng/mL to 0.9 ng/mL) postoperatively. Prostate volume was decreased by 68.2% (from 71.9 cm(3) to 22.9 cm(3)) at 4 weeks postoperatively. The mean postoperative haemoglobin drop was 11.5 g/L. The rate of transient urinary incontinence at 3 months was 3.6%. Patients who underwent bipolar transurethral enucleation and resection of the prostate had a short catheterisation time and hospital stay, which is comparable to conventional transurethral resection of the prostate. CONCLUSIONS Bipolar transurethral enucleation and resection of the prostate should become the endourological equivalent to open adenomectomy with fewer complications and short convalescence. The technique of bipolar transurethral enucleation and resection of the prostate can be acquired safely with a relatively short learning curve.
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Chan KW, Cho CL, Chu WH, Law IC. Postoperative outcomes and safety of bipolar transurethral enucleation and resection of the prostate. UROLOGICAL SCIENCE 2015. [DOI: 10.1016/j.urols.2015.06.072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Chan KW, Cho CL, Chu WH, Law IC. Postoperative outcomes and safety of bipolar transurethral enucleation and resection of the prostate. UROLOGICAL SCIENCE 2015. [DOI: 10.1016/j.urols.2015.06.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Cheng KC, Lee LF, Chan HC, Cho CL, Chau H, Lam KM, So HS. Efficacy of routine screening of urine culture before transurethral prostatectomy on the improvement of the postoperative outcome: A single-centre experience. SURGICAL PRACTICE 2014. [DOI: 10.1111/1744-1633.12094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Cho CL, Ho KL, Chu SSM, Tam PC. Robot-assisted versus standard laparoscopic partial nephrectomy: comparison of perioperative outcomes from a single institution. Hong Kong Med J 2011; 17:33-38. [PMID: 21282824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023] Open
Abstract
OBJECTIVE To evaluate the perioperative outcomes of robot-assisted laparoscopic partial nephrectomy and standard laparoscopic partial nephrectomy in a teaching hospital. DESIGN Retrospective study. SETTING Division of Urology, Department of Surgery, Queen Mary and Tung Wah hospitals, Hong Kong. PATIENTS The first 10 consecutive patients who had robot-assisted laparoscopic partial nephrectomy for renal tumours between January 2008 and September 2009 with prospective data collection were evaluated. Their outcomes were compared with the last 10 consecutive patients in our database, who had standard laparoscopic partial nephrectomy between November 2004 and October 2007. MAIN OUTCOME MEASURES Demographics, tumour characteristics, perioperative outcomes, renal function, and pathological outcomes. RESULTS There were no differences between the groups with regard to age (63 vs 56 years; P=0.313) and tumour size (2.7 vs 2.8 cm; P=0.895). No significant difference was found between the two groups with respect to the operating room time (376 vs 361 min; P=0.722), estimated blood loss (329 vs 328 mL; P=0.994), and length of hospital stay (7 vs 14 days; P=0.213). A statistically significant shorter mean warm ischaemic time for the robot-assisted group was noted (31 vs 40 minutes; P=0.032). Respective renal functional outcomes as shown by the difference between day 0 and day 60 serum creatinine levels were comparable (+10 vs +7 mmol/L; P=0.605). In both groups, there were no intra-operative complications or instances of surgical margin tumour involvement. Three patients endured postoperative complications in the standard laparoscopic group (a perinephric haematoma, urine leakage, and lymph leakage) compared with one in the robot-assisted group (a perinephric haematoma). These complications all resolved with conservative treatment. CONCLUSIONS Robot-assisted laparoscopic partial nephrectomy is a technically feasible alternative to standard laparoscopic partial nephrectomy, and provides comparable results. Robot-assisted laparoscopic partial nephrectomy appears to offer the advantage of decreased warm ischaemic time. Longer follow-up is required to assess renal function and oncological outcomes. Further experience and randomised trials are necessary to compare robot-assisted with standard laparoscopic partial nephrectomy.
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Cho CL, Lai MH, So HS, Kwok KK, Chan JC, Velayudhan V. Superselective embolisation of bilateral superior vesical arteries for management of haemorrhagic cystitis. Hong Kong Med J 2008; 14:485-488. [PMID: 19060349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
Bladder haemorrhage is common and sometimes life-threatening. Management options include bladder irrigation and supportive transfusion, intravesical instillation, endourological intervention, and surgical intervention which has poor success and high morbidity rates. Percutaneous arterial embolisation offers another minimally invasive option. We report two patients with severe haemorrhagic cystitis treated with superselective embolisation of bilateral superior vesical arteries. The technique is safe and effective for achieving immediate control of refractory bladder haemorrhage. The long-term efficacy of the procedure requires further investigation.
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Cho CL, Yuen KKY, Yuen CH, Chong LC, Chu RWS. Splenic laceration after endoscopic retrograde cholangiopancreatography. Hong Kong Med J 2008; 14:145-147. [PMID: 18382023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
Endoscopic retrograde cholangiopancreatography has been part of clinical practice for over 35 years. The procedure itself carries risks. Most complications associated with the procedure have been described in the literature. Splenic injury is an extremely rare complication after endoscopic retrograde cholangiopancreatography and only nine such cases have been reported to our knowledge since 1988. We report on a patient who presented with abdominal pain and was found to have abnormal liver function and a dilated pancreatic duct. An endoscopic retrograde cholangiopancreatography was performed and a splenic laceration was noted subsequently. As this operation is an increasingly important diagnostic and therapeutic modality for pancreatico-biliary disease, clinicians must be aware of this complication in order to make an early diagnosis and begin appropriate management.
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Chen HJ, Cho CL, Liang CL, Chen L, Chang HW, Lu K, Lee TC. Differential telomerase expression and telomere length in primary intracranial tumors. CHANG GUNG MEDICAL JOURNAL 2001; 24:352-60. [PMID: 11512366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
BACKGROUND Telomerase activity and telomere length have been shown to be involved in controlling cell proliferation and regulating cell senescence. The authors examined telomerase activity and telomere length in intracranial tumors to determine the clinicopathological behavior of primary intracranial tumors with respect to telomerase expression and alteration of telomere length. METHODS Telomerase activity was examined in 139 brain tumor samples. Telomere length was examined in 138 of the 139 samples. These tumors included 61 meningiomas, 27 schwannomas, 19 high-grade neuroepithelial tumors, and 32 low-grade neuroepithelial tumors. Telomerase activity was measured with a telomerase polymerase chain reaction, enzyme-linked immunosolvent assay kit. Telomere length was examined by Southern blot analysis for the terminal restriction fragment length. RESULTS Telomerase activity was detected in 39.2% (20/51) of the neuroepithelial tumors. Detection rates were 47.4% (9/19) for anaplastic astrocytomas and glioblastomas and 34.4% (11/32) for low-grade neuroepithelial tumors. However, detectable telomerase activity was found in 30.8% (4/13) of atypical or malignant meningiomas, but was not detected in any schwannomas. There was a highly significant difference in the telomerase detection rate in neuroepithelial or non-neuroepithelial tumors (p = 0.001). Telomere elongation was found in 11.7% (7/60) of all meningiomas, 46.1% (6/13) of atypical or malignant meningiomas, and 14.8% (4/27) of schwannomas. Elongation of telomere length was detected in 12.6% (11/87) of the cases and 23.5% (12/51) in neuroepithelial tumors. This difference was also significant (p < 0.05). Telomere length was reduced in the majority, (75%, 3/4) of malignant or atypical meningiomas with detectable telomerase activity, but only 45% (9/20) of the neuroepithelial tumors. CONCLUSION These results indicate that telomerase activation may be a critical step in the pathogenesis of intracranial tumors. Telomere length elongation also indicates a high potential for malignant behavior in these tumors.
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Lu K, Liang CL, Cho CL, Cheng CH, Yen HL, Rau CS, Tsai YD, Chen HJ, Lee TC. Patterns of palmar skin temperature alterations during transthoracic endoscopic T2 sympathectomy for palmar hyperhidrosis. Auton Neurosci 2000; 86:99-106. [PMID: 11269931 DOI: 10.1016/s1566-0702(00)00202-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Transthoracic endoscopic T2 sympathectomy has been widely applied to the treatment of a variety of sympathetically mediated disorders. Palmar hyperhidrosis is probably the most common indication for thoracic sympathectomy, especially in certain subtropical areas. Which sympathetic ganglion is to be ablated and how extensive such ablation is enough to eliminate palm sweating are two important issues. Intraoperative monitoring of palmar skin temperature (PST) is the most frequently used method for assessing the accuracy as well as adequacy of ablation of the target sympathetic ganglia. With continuous monitoring of bilateral PST during the operative course of T2 sympathectomy, it was possible to depict the alterations of bilateral PST in response to specific surgical procedures in a real-time manner. For each case, a PST graph was obtained, which represented the graphical expression of intraoperatively recorded bilateral PST data plotted against time. The PST graphs of 93 consecutive cases were analysed. Three types of PST graphs existed, reflecting different responses of bilateral PST to different surgical procedures during the operation. In Type I PST graph pattern, found in 58 cases, skin incision and intercostal muscle dissection caused dramatic bilateral PST drop; and unilateral T2 sympathectomy induced synchronous bilateral PST elevation. Twenty-four cases demonstrated Type II PST graph pattern, in which unilateral T2 sympathectomy caused only ipsilateral PST elevation, although the PST-depressing effect of skin incision and muscle dissection was as significant as in Type I graph pattern. In the 11 cases who showed Type III PST graph pattern, neither skin incision nor T2 sympathectomy induced any apparent changes of PST on either side, giving rise to two rather flat PST curves on the PST graphs. These findings implicate that reciprocal interactions between bilateral sympathetic activities exist in the majority of cases, and that crossover sympathetic modulation may play a role in the neural control of the sudomotor and vasomotor activities of the palms. This study also provides information regarding how PST would possibly change following specific surgical procedures during transthoracic endoscopic T2 sympathectomy, which may be of importance to those who use intraoperative PST monitoring as a guide in determining whether or not the correct sympathetic ganglia are ablated for adequate sympathetic denervation of the palms.
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Chen HJ, Liang CL, Lu K, Lin JW, Cho CL. Implication of telomerase activity and alternations of telomere length in the histologic characteristics of intracranial meningiomas. Cancer 2000; 89:2092-8. [PMID: 11066050 DOI: 10.1002/1097-0142(20001115)89:10<2092::aid-cncr9>3.0.co;2-n] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Telomerase activity and telomere length have been shown to be involved in the control of cell proliferation and regulation of cell senescence. The expression of telomerase activity may endow cells with the capacity of unlimited proliferation and immortality. The authors examined the telomerase activity and telomere length of intracranial meningiomas to determine the relation between the results and the clinicopathologic behavior of these tumors. METHODS Sixty-two specimens of meningiomas including 13 atypical and malignant tumors were used in this study. Telomerase activity was measured with polymerase chain reaction and enzyme-linked immunosolvent assay. Telomere length was measured by detecting the terminal restriction fragments using Southern blots. RESULTS Detectable telomerase activity was found in 4 of 13 (30.8%) malignant or atypical meningiomas and only 1 in 49 benign meningiomas (P = 0.006). Elongated telomere length was measured in 6 of 13 (46.1%) patients with malignant or atypical meningiomas and only 1 of 48 (2.1%) in those with benign tumors (P = 0.0002). Three of 4 (75%) of malignant or atypical meningiomas with detectable telomerase activity revealed shortened telomere length, and all tumors with elongated telomere length displayed undetectable telomerase activity. The percentage of malignant or atypical meningiomas with detectable telomerase activity or elongated telomere were significantly higher (76.9%) than that of benign tumors (4.0%). The proliferative index was calculated as the percentage of tumor cell nuclei immunoreactive for Ki-67 to total tumor nuclei. The mean values of proliferative index in benign, atypical, and malignant meningiomas were 1.2, 11.0, and 30.0, respectively. CONCLUSIONS The results indicate that telomerase activation may be a critical step in the pathogenesis of malignant or atypical meningioma. Elongation of the telomere length also implicates the high potential for malignant behavior in these tumors.
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Hwang CF, Su CY, Kou SC, Huang SC, Leung SW, Huang CM, Cho CL. Diagnostic usefulness of telomerase activity in nasopharyngeal carcinoma. Jpn J Cancer Res 2000; 91:760-6. [PMID: 10920285 PMCID: PMC5926413 DOI: 10.1111/j.1349-7006.2000.tb01010.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Telomeres are specialized structures at the ends of eukaryotic chromosomes which are composed of simple repetitive G-rich hexameric sequences. Activation of telomerase, a ribonucleoprotein that synthesizes telomeric DNA, is found in most malignant tumors. However, little data is available concerning the correlation between telomerase activity and NPC (nasopharyngeal carcinoma). In this study, telomerase activation was determined using the TRAP (telomerase repeat amplification protocol) assay in 62 nasopharyngeal biopsies (25 NPC, 25 non-malignant nasopharyngeal lymphoid tissues, 12 post-irradiated nasopharyngeal tissues). The results showed that strong telomerase activity was present in both NPC and non-malignant nasopharyngeal biopsies. Post-irradiated nasopharyngeal samples had a significantly lower telomerase activity than NPC and non-malignant nasopharyngeal lymphoid tissues. It is well known that nasopharyngeal tissue is infiltrated by numerous lymphocytes, which might retain telomerase activity. Therefore, the finding that the telomerase activation was lowest in post-irradiated nasopharyngeal tissues is reasonable because of the destruction of activated lymphocytes and NPC by radiation. NPC biopsies with positive lymph node involvement exhibited higher levels of telomerase compared to those without lymph node involvement. Our data indicate a positive association between telomerase activity and tumor potential for lymphatic spreading in limited local tumors. In addition, telomerase activity may be useful as a diagnostic marker in the detection of tumor cells in recurrent NPC, but not in primary NPC.
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ChangChien CC, Lin H, Leung SW, Hsu CY, Cho CL. Effect of acetic acid on telomerase activity in cervical intraepithelial neoplasia. Gynecol Oncol 1998; 71:99-103. [PMID: 9784327 DOI: 10.1006/gyno.1998.5143] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To evaluate whether the telomerase activity in CIN lesions can be affected by a chemical solution of acetic acid, which is required to apply to the cervix prior to colposcopy-directed biopsy. MATERIALS AND METHODS Thirty-five patients with histologically confirmed high-grade squamous intraepithelial lesions of the cervix entered the study. Two specimens were collected from each patient, one before and one after the cervix was swabbed with 5% acetic acid. The standard telomeric repeat assay protocol (TRAP) was used to examine telomerase activity in these fresh frozen tissue samples. Normal cervical tissues from 10 control individuals were also examined for the presence of telomerase activity. A total of 80 specimens was analyzed. RESULTS Telomerase activity was detectable in 27 of 35 (77.1%) fresh tissue samples, 15 of 35 (42.9%) tissue samples swabbed with 5% acetic acid, and 0 of 10 (0%) normal cervical tissue samples, respectively. Twelve samples became telomerase negative after 5% acetic acid applied. Among the 15 telomerase-positive tissue samples swabbed with 5% acetic acid, 12 had relative weak telomerase activity compared to corresponding fresh tissue samples, the other 3 remained the same. Therefore, it is concluded that telomerase activity was affected by 5% acetic acid in 24 of 27 (88.9%) samples. Telomerase activity in HeLa cell line was also inhibited by 5% acetic acid. CONCLUSION We reported a relative high percentage of telomerase expression in high-grade CIN lesions when compared with previous reports. If detection of telomerase activity is to become a tool for diagnosis and prognosis of cervical neoplasias, applying acetic acid prior to colposcopy-directed biopsy that is submitted for telomerase assay should be avoided in order to increase the detection rate.
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Chang TG, Wang J, Chen LW, Hsu CY, Chang HW, Chen JS, Cho CL. Loss of expression of the p16 gene is frequent in malignant skin tumors. Biochem Biophys Res Commun 1997; 230:85-8. [PMID: 9020067 DOI: 10.1006/bbrc.1996.5891] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Expression of the p16 gene from 30 malignant skin tumors has been surveyed by immunohistochemical assay. Gene point mutations were detected by DNA direct sequencing and the mRNA level of gene expression was measured by RT-PCR. A silent point mutation of the p16 gene was found in only one patient. However, loss of expression of the p16 gene was noticed in 23 of 29 samples (79.3%). Correlation between loss of expression of the p16 gene and metastasis is significant (p = 0.0036). These findings suggest that loss of expression of the p16 gene may play a critical role in tumor progression of malignant skin tumors.
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Mannen H, Tseng HM, Cho CL, Li SS. Cloning and expression of human homolog HSMT3 to yeast SMT3 suppressor of MIF2 mutations in a centromere protein gene. Biochem Biophys Res Commun 1996; 222:178-80. [PMID: 8630065 DOI: 10.1006/bbrc.1996.0717] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A human HSMT3 cDNA encoding a homolog of the yeast SMT3, a suppressor of MIF2 mutations in a centromere protein gene, was identified and sequenced. The sequence of 95 amino acids deduced from the human HSMT3 cDNA exhibited 51.1% identity and 69.6% similarity to the yeast Smt3p sequence. The HSMT3 transcripts of 1.35Kb were found to be abundantly expressed in various human tissues.
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Majumdar MK, Cho CL, Fox MT, Eckner KL, Kozak S, Kabat D, Geib RW. Mutations in the env gene of friend spleen focus-forming virus overcome Fv-2r-mediated resistance to Friend virus-induced erythroleukemia. J Virol 1992; 66:3652-60. [PMID: 1583724 PMCID: PMC241148 DOI: 10.1128/jvi.66.6.3652-3660.1992] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Although Fv-2r homozygous mice are resistant to leukemias induced either by an erythropoietin-encoding virus or by wild-type Friend virus (FV) (M. E. Hoatlin, S. L. Kozak, F. Lilly, A. Chakraborti, C. A. Kozak, and D. Kabat, Proc. Natl. Acad. Sci. USA 87:9985-9989, 1990), they are susceptible to some variants of FV (R. A. Steeves, E. A. Mirand, A. Bulba, and P. J. Trudel, Int. J. Cancer 5:349-356, 1970; R. W. Geib, M. B. Seaward, M. L. Stevens, C.-L. Cho, and M. Majumdar, Virus Res. 14:161-174, 1989). To localize the virus gene involved in influencing the host range, we cloned and sequenced the env gene of the BB6 variant of FV (Steeves et al., Int. J. Cancer 5:349-356, 1970). In comparison with the wild-type env gene, the BB6 variant contains a 159-bp deletion that eliminates the membrane-proximal portion of the extracellular domain and 58 point mutations resulting in 13 amino acid changes. Substitution of the variant env gene for the wild-type env gene resulted in a recombinant virus that produced a Friend virus-like disease in Fv-2r homozygotes. Our results identify the spleen focus-forming virus env gene as the viral gene involved in this virus-host interaction. Additionally, they suggest that the product of the Fv-2r gene modifies the interaction between the spleen focus-forming virus envelope protein and the erythropoietin receptor.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Cell Transformation, Neoplastic
- Cloning, Molecular
- Friend murine leukemia virus/genetics
- Friend murine leukemia virus/pathogenicity
- Gene Amplification
- Genes, env/genetics
- Host-Parasite Interactions/genetics
- Immunity, Innate/genetics
- Leukemia, Erythroblastic, Acute/genetics
- Leukemia, Erythroblastic, Acute/pathology
- Leukemia, Experimental/genetics
- Leukemia, Experimental/pathology
- Mice
- Mice, Inbred Strains
- Molecular Sequence Data
- Mutation
- Sequence Homology, Nucleic Acid
- Spleen/microbiology
- Spleen Focus-Forming Viruses/genetics
- Spleen Focus-Forming Viruses/pathogenicity
- Virus Activation
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Geib RW, Seaward MB, Stevens ML, Cho CL, Majumdar M. RB virus: a strain of Friend virus that produces a 'Friend virus-like' disease in Fv-2rr mice. Virus Res 1989; 14:161-73. [PMID: 2609775 DOI: 10.1016/0168-1702(89)90036-1] [Citation(s) in RCA: 5] [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
RB virus is a newly derived strain of Friend virus that was adapted to produce a 'Friend-like' disease in mice that are genetically resistant to wild-type Friend virus. RB virus was produced by passing high titers of the wild-type Friend virus (Lilly-Steeves polycythemia-producing strain) through adult Fv-2rr mice. Titration of the defective spleen focus-forming virus indicated RB virus infected similar numbers of Fv-2ss or Fv-2rr target cells. Analysis of the spleens from mice infected with RB virus indicated that RB induced the early stage of Friend disease (erythroid proliferation) in both Fv-2rr and Fv-2ss mice. Fv-2ss mice infected with RB virus developed the classical Friend disease within 3 weeks. In contrast, the percentage of Fv-2rr mice developing the 'Friend-like' disease after infection with RB virus never exceeded 60%. The latency period of RBV in Fv-2rr mice was strain dependent. D2.R16 (Fv-2rr) developed the syndrome more rapidly than C57BL/6 (Fv-2rr). RB virus retained the capacity to transform erythroprogenitor cells from both Fv-2ss and Fv-2rr animals. Cells infected with RB virus consistently produced a modified SFFV envelope protein, gp48.
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