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S-H Yang

Publications and source records attributed to S-H Yang.

16 recordsLinked to original sources
PubMed2006

Correlation of antiviral T-cell responses with suppression of viral rebound in chronic hepatitis B carriers: a proof-of-concept study.

Despite recent advances in the chemotherapy of chronic hepatitis B (CHB), an effective viral suppression after cessation of therapy has not yet been achieved. To investigate whether hepatitis B virus (HBV)-specific T-cell responses are inducible and can contribute to the viral suppression after cessation of the therapy, we conducted a proof-of-concept study with a DNA vaccine comprising of most HBV genes plus genetically engineered interleukin-12 DNA (IL-12N222L) in 12 CHB carriers being treated with lamivudine (LAM). When the ex vivo and/or cultured IFN-gamma enzyme-linked immunospot (ELISPOT) assay was performed, the detectable HBV-specific IFN-gamma secreting T-cell responses were observed at the end of treatment and during a follow-up. These type 1T-cell responses, particularly CD4(+) memory T-cell responses could be maintained for at least 40 weeks after the therapy and correlated with virological responses, but not with alanine aminotransferase elevation. Moreover, DNA vaccination under LAM treatment appeared to be well-tolerated and showed 50% of virological response rate in CHB carriers. Thus, a combination therapy of the DNA vaccine with chemotherapy may be one of new immunotherapeutic methods for the cure of CHB.

Adult↗
PubMed2006

Anatomical and functional significance of urogenital hiatus in primary urodynamic stress incontinence.

OBJECTIVES: To explore the correlations of anatomical and functional sonographic parameters of urogenital hiatus in primary urodynamic stress incontinence. METHODS: We reviewed retrospectively our urodynamic database from July 1996 to June 2003 and identified subjects with primary urodynamic stress incontinence who had had anatomical assessment of the lower urinary tract and the central part of the pelvic floor by ultrasound. The morphological changes that had occurred in the central pelvic floor were determined by the measurement of genitohiatal angle, genitohiatal distance and anorectal angle. RESULTS: A total of 396 women with a mean age of 48.8 +/- 10.7 (range, 26-82) years were included in the study. One hundred and eighteen subjects (29.8%) were postmenopausal. Stage I pelvic organ prolapse was found in 345 (87.1%) of the women, stage II in 19 (4.8%) and stage III in 32 (8.1%). The genitohiatal angle and genitohiatal distance were significantly and positively associated with resting and straining bladder neck angles. The genitohiatal angle was associated with bladder neck funneling and dependent cystocele during stress (r = 0.144, P = 0.016 and r = 0.140, P = 0.02, respectively), and it was negatively associated with functional profile length (r = -0.157, P = 0.012). The genitohiatal distance was negatively associated with functional profile length and maximum urethral closure pressure (r = -0.148, P = 0.018 and r = -0.227, P = 0.009, respectively). Increased genitohiatal distance was also related to a low Valsalva leak-point pressure (r = -0.199, P = 0.02). Multivariate analysis revealed that resting bladder neck angle was the independent factor for genitohiatal angle and genitohiatal distance. CONCLUSIONS: In primary urodynamic stress incontinence, an increased resting genitohiatal distance or genitohiatal angle on sonographic imaging implies anterior vaginal wall prolapse. In addition, an increased genitohiatal distance is associated with functional impairment of urethral closure.

Adult↗
PubMed2006

Transvaginal sonography in the morphological and functional assessment of segmental dilation of the distal ureter.

Primary megaureter presents a spectrum of findings ranging from mild, clinically unimportant, stable ureterectasis to severe, progressive obstructive hydroureteronephrosis. We report a patient with a double uterus and ipsilateral renal dystrophy. A previous imaging study had revealed a double uterus and obstructed left hemivagina, into which a single vaginal ectopic ureter inserted. On follow-up intravenous urography 8 years later, the left kidney was non-functioning, and there was segmental dilation of the distal right ureter. Transvaginal sonography with real-time scanning and Doppler were useful in exploring the morphological and functional status of this dilated distal ureter.

Abnormalities, Multiple↗
PubMed2006

Ultrasonographic characteristics and cystoscopic correlates of bladder wall invasion by endophytic cervical cancer.

OBJECTIVES: To present the ultrasonographic findings and explore cystoscopic correlates of endophytic cervical cancer invading the bladder wall. METHODS: We retrospectively reviewed the imaging files in 19 cases of cervical cancer, comprising six cases of endophytic lesions invading the bladder wall (study group) and 13 cases of endo- or exophytic, clinical stage IB1 lesions without bladder wall invasion (controls). Bladder wall infiltration or invasion was confirmed by cystoscopic biopsy or surgical findings or both. All 19 patients had undergone transvaginal ultrasound examination to evaluate the cervix and lower urinary tract. The main measures included tumor volume of the primary cervical neoplasm, tumor protuberance, mobility of the cervix over the lower bladder wall, continuity of the endopelvic fascia and echogenicity and morphological texture of the bladder wall and its thickness. RESULTS: A tumor protuberance emerging from the cervicocorporeal junction and invading the bladder in the supratrigonal area was seen in the study group but not in the controls. Disruption of the endopelvic fascia, a thickened bladder wall, changes in the bladder mucosa and interruption of the entire bladder wall were ultrasonographic characteristics demonstrating the sequential stages of bladder wall invasion. The morphological changes in the bladder wall on ultrasound examination were categorized into four stages. Based on the morphological classification, two of the six patients in the study group belonged to stage I, one to stage II, one to stage III and two to stage IV of bladder wall invasion. CONCLUSIONS: In cervical cancer, transvaginal ultrasonography helps to explore sequential changes seen in bladder wall invasion, information that is not as readily available from cystoscopic examination.

Adult↗
PubMed2006

Two- and three-dimensional ultrasonographic findings in urethral stenosis with bladder wall trabeculation: case report.

Female bladder outlet obstruction is uncommon. We report a case of bladder outlet obstruction secondary to urethral stenosis leading to bladder wall trabeculation. The patient presented at our clinic because of lower urinary tract symptoms including nocturia, urgency, bed wetting, hesitancy, straining to void, and incomplete emptying. Urodynamic study revealed a low maximum free uroflow rate, high residual urine volume, and low compliance on filling phase cystometry. Introital ultrasonography with two- and three-dimensional (2D and 3D) scanning displayed a constriction in the echolucent part of the lower-mid urethra with hyperechogenicity and a lattice-like appearance of the bladder wall. Cystourethroscopy confirmed urethral stenosis and bladder wall trabeculation. The voiding symptoms subsided after the urethral stenosis was relieved by urethral dilatation, but, despite some improvement, the irritative symptoms persisted. Introital ultrasonography with 2D and 3D scanning may help to clarify the cause of female bladder outlet obstruction.

Female↗
PubMed2006

Functional correlates of Doppler flow study of the female urethral vasculature.

OBJECTIVES: To examine the effect of individual patient factors (age, parity, body mass index, menstrual cycle, menopause, hormone replacement therapy, bladder neck position and urethral mobility) on the appearance of Doppler flow in urethral vessels, to investigate the association between the Doppler flow parameters and intrinsic urethral function, storage and voiding, and to explore differences in the urethral vasculature between subjects with and without urodynamic stress incontinence (USI). METHODS: Over a 4-year period we prospectively performed imaging studies in 355 women, including 244 who denied any lower urinary tract symptoms within the previous 3 months (Group A) and 111 who had had lower urinary tract symptoms (Group B). Studies included morphologic assessment and Doppler flow investigation of the lower urinary tract. Vascular flow velocity and vessel density in the urethral vasculature were measured. For women in Group B, multichannel urodynamic studies were also performed. RESULTS: The urethral vasculature has five main branches of vessels. Their appearance was not affected by the menstrual cycle or menopause except for those of the anterior vaginal vessel and anterior branch of the middle urethral vessel. Other than that of the posterior urethral vessel, in which there was a correlation with parity, the resistance index (RI) was not affected by individual patient factors. However, there was a correlation between the vascular index (VI) and individual factors such as age (r = -0.336, P = 0.002), body mass index (r = -0.287, P = 0.028), menopause (r = -0.402, P < 0.001), and hormone replacement therapy (r = 0.392, P = 0.027). Only the VI and RI of the posterior urethral vessel correlated significantly with the urethral pressure profile. In subjects with lower urinary tract symptoms, the appearance of the urethral vasculature on power Doppler imaging and the corresponding RI and VI values were not correlated with objective evidence of USI. CONCLUSION: Patient factors may affect specific Doppler flow parameters of the urethral vasculature, which are related to intrinsic resting urethral closure. There is no difference in the appearance of the urethral vasculature in subjects with or without USI.

Adult↗
PubMed2006

Biometry of the pubovisceral muscle and levator hiatus in nulliparous Chinese women.

OBJECTIVES: To identify using three-dimensional (3D) ultrasound the morphological features and normal biometry of the levator hiatus in nulliparous Chinese women and to explore ethnic differences between these measurements and those in nulliparous Caucasian women. METHODS: 3D sonographic data from 59 nulliparous Chinese women (aged 19-38 years) who had no pelvic organ prolapse and no symptoms of pelvic floor dysfunction were retrieved from an image dataset and analyzed by offline post-processing. The pubovisceral muscle and levator hiatus were measured in the planes of maximal pubovisceral muscle thickness and minimum hiatal dimension, respectively. In addition, the genitohiatal and levator ani angles were measured. These values were compared with those in a published study of Caucasian women. RESULTS: In Chinese women there was no relationship between minimum anteroposterior (AP) hiatal diameter and minimum lateral hiatal diameter. Body weight was correlated with hiatal area and minimum AP hiatal diameter (r = 0.391, P = 0.003 and r = 0.378, P = 0.004, respectively), whereas body mass index was correlated only with minimum AP hiatal diameter (r = 0.349, P = 0.008). There was a significant difference in average pubovisceral muscle thickness (P = 0.001) between nulliparous Chinese and Caucasian women. CONCLUSIONS: Body weight, body mass index, and ethnicity are factors affecting the biometry of the levator hiatus in Chinese nulliparous women.

Adult↗
PubMed2005

Transvaginal sonography in the diagnosis, management and follow-up of complex paraurethral abnormalities.

Most urethral diverticula are thought to result from infection and obstruction of the paraurethral ducts and glands. When rupture of a resulting retention cyst or abscess occurs into the urethra, a diverticulum is formed. We report two cases of paraurethral abnormalities: urethral diverticulum and paraurethral abscess. Transvaginal sonography, with its high-resolution visualization of the lower urinary tract, may aid in the diagnosis and treatment of such disorders. Using three-dimensional technology, the internal architecture of the paraurethral abnormalities and their spatial relationship to the urethra and bladder, important considerations at surgery, are clearly demonstrated on ultrasonography. Complete excision of complex paraurethral anomalies may be performed under transvaginal sonographic monitoring without inadvertent injury to the bladder or urethra.

Abscess↗
PubMed2005

Dynamic morphological changes in the anterior vaginal wall before and after laparoscopic Burch colposuspension in primary urodynamic stress incontinence.

OBJECTIVE: To evaluate dynamic morphological changes in the anterior vaginal wall in primary urodynamic stress incontinence before and after laparoscopic Burch colposuspension and to explore the related effects on urethral and voiding functions. METHODS: Ultrasound cystourethrography and urodynamic study were performed in 112 patients with primary urodynamic stress incontinence before and 3 months after laparoscopic Burch colposuspension. Ultrasound assessment included measurement of the bladder neck positions at rest and during straining, the bladder wall thickness at the dome and trigone, and observation of the motion of the bladder neck in addition to the development of cystocele on Valsalva maneuver. On ultrasonography, a cystocele was defined as prolapse or descent of the bladder base below the bladder neck at rest, on Valsalva, or both. RESULTS: After laparoscopic Burch colposuspension, ultrasound cystourethrography revealed significant differences in the bladder neck position at rest and during stress (preoperative median 93 degrees vs. postoperative 70 degrees at rest and preoperative 160 degrees vs. postoperative 81 degrees during stress, P < 0.001, respectively) and rotational angle (preoperative median 58 degrees vs. postoperative 10 degrees , P < 0.001). A laparoscopic Burch operation corrected 50% (5/10) of the preoperative cystoceles. However, a residual cystocele developed postoperatively in 29% (30/102) of the women who did not have one previously. Postoperative ultrasonographic and urodynamic studies did not reveal any differences between those women with or without postoperative cystocele except for the residual urine volume, detrusor opening pressure, and straining and rotational angles of the bladder neck (P < 0.001, 0.032, 0.010 and < 0.001, respectively). CONCLUSIONS: Laparoscopic Burch colposuspension may correct a pre-existing cystocele, but in other patients a cystocele may persist or be disclosed. After laparoscopic Burch operation a persistent cystocele is not associated with urethral compression or voiding impairment.

Adult↗
PubMed2005

Two- and three-dimensional sonographic findings in a case of distal urethral obstruction due to a paraurethral tumor.

The cause of bladder outlet obstruction in women may be categorized generally into two types, functional and anatomical. On ultrasonography, the urethra appears as a tubular structure with a central echolucent part and surrounding hyperechogenic structures. Morphological changes in the echolucent portion of the urethra have been reported to be associated with voiding dysfunction. We present a case of distal urethral obstruction secondary to metastatic paraurethral adenocarcinoma. Three-dimensional sonography clearly demonstrated the configuration of the metastatic tumor and its spatial orientation in association with distal urethral obstruction.

Adenocarcinoma↗
PubMed2005

Transvaginal sonography in the assessment of distal ureteral calculi.

OBJECTIVES: To explore the morphological and functional findings of transvaginal sonography (TVS) in the diagnosis and management of distal ureteral calculi. METHODS: We retrospectively reviewed the imaging studies in seven cases of distal ureteral calculi (study group) and 20 cases of female volunteers without urinary tract infection (control group). All 27 patients had undergone TVS for assessment of the lower urinary tract. The variables measured on ultrasound included the presence or absence of distal ureteral calculi, the size and location of a calculus if present, the presence or absence of the ureter jet phenomenon, morphological changes of the ureteral papilla and adjoining tissue, and the height of the ureteral papilla, as well as vascular changes seen on Doppler imaging. RESULTS: In the controls, 80% of the ureteral papillae were triangular and 20% trapezoidal. The average (+/-SD) height of the ureteral papillae was 3.5 +/- 0.7 mm on the right and 3.6 +/- 0.9 mm on the left. There was no statistically significant difference between the heights of the right and left papillae (P = 0.619). In the study group, echogenic stones were identified in all seven patients and a hypoechogenic tubular structure connected to the involved papilla was identified in 6/7 patients. The average height of the involved papilla was 6.7 +/- 1.6 mm. Ureteric jets were visible in all patients in both the study and control groups. CONCLUSION: In patients with distal ureteral calculi, TVS provides a rapid, non-invasive and repeatable means of assessing the morphology and function of the distal ureter.

Adult↗
PubMed2005

Estrogens, progestins, menopause and neurodegeneration: basic and clinical studies.

Two classes of ovarian steroids, estrogens and progestins, are potent in protecting neurons against acute toxic events as well as chronic neurodegeneration. Herein we review the evidence for neuroprotection by both classes of steroids, provide plausible mechanisms for these potent neuroprotective activities and indicate the need for further clinical trials of both estrogens and progestins in protection against acute and chronic conditions that cause neuronal death. Estrogens at concentrations ranging from physiological to pharmacological are neuroprotective in a variety of in vitro and in vivo models of cerebral ischemia and brain trauma as well as in reducing key neuropathologies of Alzheimer's disease. While the mechanisms of this potent neuroprotection are currently unresolved, a mitochondrial mechanism is involved. Progestins have been recently shown to activate many of the signaling pathways used by estrogens to neuroprotect, and progestins have been shown to protect against neuronal loss in vitro and in vivo in a variety of models of acute insult. Collectively, results of these animal and tissue culture models suggest that the loss of both estrogens and progestins at the menopause makes the brain more vulnerable to acute insults and chronic neurodegenerative diseases. Further clinical assessment of appropriate regimens of estrogens, progestins and their combination are supported by these data.

Animals↗
PubMed2004

Direct observation of high-temperature polaronic behavior in colossal magnetoresistive manganites.

The temperature dependence of the electronic and atomic structure of the colossal magnetoresistive oxides La1-xSrxMnO3 (x=0.3, 0.4) has been studied using core and valence level photoemission, x-ray absorption and emission, and extended x-ray absorption fine structure spectroscopy. A dramatic and reversible change of the electronic structure is observed on crossing the Curie temperature, including charge localization on and spin-moment increase of Mn, together with Jahn-Teller distortions, both signatures of polaron formation. Our data are also consistent with a phase-separation scenario.

Journal Article↗
PubMed2003

Activation of p53 signalling in acetylsalicylic acid-induced apoptosis in OC2 human oral cancer cells.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) such as acetylsalicylic acid (ASA, aspirin) are well known chemotherapeutic agents of cancers; however, the signalling molecules involved remain unclear. The aim of this study was to investigate the possible existence of a putative p53-dependent pathway underlying the ASA-induced apoptosis in OC2 cells, a human oral cancer cell line. MATERIALS AND METHODS: The methyl tetrazolium (MTT) assay was employed to quantify differences in cell viability. DNA ladder formation on agarose electrophoresis was used as apoptosis assay. The expression levels of several master regulatory molecules controlling various signal pathways were monitored using the immunoblotting techniques. Flow cytometry was used to confirm the effect of ASA on cell cycle. Patterns of changes in expression were scanned and analyzed using the NIH image 1.56 software (NIH, Bethesda, MD, USA). All the data were analyzed by ANOVA. RESULTS: Acetylsalicylic acid reduced cell viability and presence of internucleosomal DNA fragmentation. In the meanwhile, phosphorylation of p53 at serine 15, accumulation of p53 and increased the expression of its downstream target genes, p21 and Bax induced by ASA. The expression of cyclooxygenase-2 was suppressed. Disruption of p53-murine double minute-2 (MDM2) complex formation resulted in increasing the expression of MDM2 60-kDa cleavage fragment. Inhibited the activation of p42/p44 mitogen-activated protein kinase (MAPK) by PD98059, a specific inhibitor of extracellular regulatory kinase (ERK), significantly decreased cell viability and enhanced the expression of p53 induced by ASA. The result of the cell-cycle analysis showed that ASA and PD98059 induced the cell cycle arrested at the G0/G1 phase and resulted in apoptosis. CONCLUSION: Nonsteroidal anti-inflammatory drug-inhibited cyclooxygenase is not the only or even the most important mechanism of inhibition. Our study presents evidences that activation of p53 signalling involved in apoptosis induced by ASA. Furthermore, the apoptotic effect was enhanced by blocking the activation of p42/p44 MAPK in response to treatment with ASA, thus indicating a negative role for p42/p44 MAPK.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2003

Rapid prototyping strategy for a surgical data warehouse.

OBJECTIVES: Healthcare processes typically generate an enormous volume of patient information. This information largely represents unexploited knowledge, since current hospital operational systems (e.g., HIS, RIS) are not suitable for knowledge exploitation. Data warehousing provides an attractive method for solving these problems, but the process is very complicated. This study presents a novel strategy for effectively implementing a healthcare data warehouse. METHODS: This study adopted the rapid prototyping (RP) method, which involves intensive interactions. System developers and users were closely linked throughout the life cycle of the system development. The presence of iterative RP loops meant that the system requirements were increasingly integrated and problems were gradually solved, such that the prototype system evolved into the final operational system. RESULTS: The results were analyzed by monitoring the series of iterative RP loops. First a definite workflow for ensuring data completeness was established, taking a patient-oriented viewpoint when collecting the data. Subsequently the system architecture was determined for data retrieval, storage, and manipulation. This architecture also clarifies the relationships among the novel system and legacy systems. Finally, a graphic user interface for data presentation was implemented. CONCLUSIONS: Our results clearly demonstrate the potential for adopting an RP strategy in the successful establishment of a healthcare data warehouse. The strategy can be modified and expanded to provide new services or support new application domains. The design patterns and modular architecture used in the framework will be useful in solving problems in different healthcare domains.

Colorectal Surgery↗