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Biomedical subjects

C C Liang

Publications and source records attributed to C C Liang.

At least 37 records · Page 2Linked to original sources

Measurement and pharmacokinetic study of tetramethylpyrazine in rat blood and its regional brain tissue by high-performance liquid chromatography.

We used a rapid, sensitive and reliable high-performance liquid chromatographic method for the determination of tetramethylpyrazine in rat brain tissue and plasma. The lower limit of quantification in plasma and brain tissue was 0.1 microgram/ml and 0.1 microgram/g, respectively, and only a small amount of plasma (100 microliters) or brain tissue (100 micrograms) was required for analysis. The decline in the concentration of tetramethylpyrazine in plasma was generally two-exponential at a dose of 2, 5, or 10 mg/kg administered intravenously. Concentrations of tetramethylpyrazine in various regions of the brain (cerebral cortex, brainstem, striatum, hippocampus, cerebellum and midbrain) were not significantly different at 15 min following drug administration (10 mg/kg, i.v.). In additional analysis, mean concentration of the tetramethylpyrazine in rat plasma was approximately five-times greater than the drug in brain tissue.

Animals↗

A study of diagnostic failure of loop conization in microinvasive carcinoma of the cervix.

OBJECTIVE: The aim of this study was to evaluate the specimen adequacy and the histological interpretation of loop conization for microinvasive cervical carcinoma. METHODS: We retrospectively reviewed the histopathological findings of the original cone specimens together with the final hysterectomy specimens in patients with microinvasive carcinoma of the cervix. From 1990 to 1995, 63 consecutive patients with microinvasive carcinoma of the cervix were included in the study, of which 35 patients underwent loop conization and 28 underwent cold-knife conization. All patients had a hysterectomy. RESULTS: The mean width, depth, and cone volume of the conization specimens were 2.44 cm, 2.15 cm, and 3.96 cm3, respectively, in the loop group versus 2.3 cm, 2.35 cm, and 4.38 cm3 in the cold-knife group. No significant differences were seen between the two groups. The application of loop conization was completed in a single slice in 27 patients (77.1%) and multiple slices by the loop in 8 (22.9%), in spite of the attempt to perform conization in a one-pass application when possible. In assessing these cone specimens microscopically, the rate of transection of tissue was significantly higher in the loop cone than in the cold-knife cone (17.1% versus 0%, P = 0.02). Because of transection of tissue and misorientation, pathologic determination of the depth and width of stromal invasion was undetermined in two loop cone specimens compared with none in the cold-knife cones. CONCLUSION: Our study suggests that cold-knife conization is a preferred method in assessing microinvasive carcinoma of the cervix if multiple applications of loop conization are inevitable.

Adult↗

Ophthalmologic outcome of transvenous embolization of spontaneous carotid-cavernous fistulas: a preliminary report.

We give a preliminary report of the ophthalmologic outcome of four patients with transvenous embolization studied for their spontaneous carotid-cavernous fistulas. One of them is a direct type while three of them are indirect dural shunts. In indirect dural shunts, traditional transarterial embolization rarely achieves a complete clinical cure in a short period of time. All cases had an ophthalmologic disturbance justified for endovascular intervention. We performed catheterization, and subsequently embolization with Guglielmi Detachable coils, to the cavernous sinus via the femoral vein and inferior petrosal sinus/superior ophthalmic vein. All four patients achieved clinical and angiographic improvement with a follow-up period range from two to sixteen months except for one patient who had residual bilateral sixth nerve palsy. The transvenous approach offers an effective and safe alternative for the management of spontaneous carotid-cavernous fistula.

Abducens Nerve Diseases↗

Generation of stable recombinant retroviruses containing the beta-globin genes linked to complex regulatory elements by using transient transfection.

A transient packaging method for a retroviral vector containing beta-globin sequences, mediated by Ca3(PO4)2 precipitation, generated stable recombinant beta-globin retroviruses with intact viral genomes. We suggest the use of this method as an alternative means to overcome the production of beta-globin encoding retroviruses with aberrant viral genomes using the routine packaging procedure.

Genetic Vectors↗

Perinatal transmission of human papillomavirus in infants: relationship between infection rate and mode of delivery.

OBJECTIVE: To determine the transmission rate of human papillomavirus (HPV) in newborn infants of HPV-positive women and to assess the relationship between perinatal HPV transmission and mode of delivery. METHODS: Three hundred one pregnant women were selected: vaginal delivery (n = 160) or cesarean delivery (n = 141). We assessed the presence of the HPV types 16 and 18 DNA sequences in buccal and genital swabs of neonates born to HPV-positive mothers, using the polymerase chain reaction. RESULTS: The overall frequency of HPV 16/18 infection among the pregnant women was 22.6% (68/301). At birth, the overall frequency of HPV transmission from HPV 16/18-positive mothers to newborns was 39.7% (27/68). A significantly higher rate of HPV 16/18 infection was found at birth when infants were delivered vaginally than when infants were delivered by cesarean (18/35 or 51.4% versus 9/33 or 27.3%, P = .042). However, there was no significant difference in the incidence of perinatal HPV infection between the HPV types 16 and 18 in either vaginal delivery group or in the cesarean delivery group (all P > .100). No significant difference was found between the buccal and genital sites (27/68 versus 21/68, P = .234) or between male and female infants overall (12/36 versus 15/32, P = .255). CONCLUSION: The findings suggest that neonates are at higher risk for exposure to HPV after vaginal delivery than after cesarean delivery.

Adolescent↗

Inversion and transposition of Tc1 transposon of C. elegans in mammalian cells.

Tc1/mariner transposons are widespread in the eukaryotes. In vitro transposition test indicated that the transposase is the only protein that is needed in transpositions. It was shown later that the reconstructed Tc1-like transposon, "sleeping beauty" in fish, and the Tc1 transposon in C. elegans jumps in human cells. This discovery indicates that the Tc1/mariner transposon may be engineered as a somatic gene therapy vector if coupled with an efficient gene delivery system. We introduced the Tc1 transposon from C. elegans into different mammalian cell lines and detected the transposition events, indicating that Tc1 transposon functions in different mammalian cells. Interestingly, a high inversion frequency of the transposon was also detected, suggesting that this type of transposon may add variations to host genome when it is horizontally transferred into a new species.

Animals↗

Prenatal diagnosis of tetralogy of Fallot with absent pulmonary valve accompanied by hydrops fetalis.

Tetralogy of Fallot with absent pulmonary valve is a rare congenital cardiac anomaly. We report on the echocardiographic features of a fetus with such an anomaly and aneurysm of the pulmonary artery associated with hydrops fetalis and polyhydramnios. The prognosis of tetralogy of Fallot with absent pulmonary valve and pulmonary aneurysm is grave, especially in a fetus with intrauterine heart failure. Serial sonographic follow-up is mandatory to detect the signs of hydrops fetalis. Early intervention and intensive treatment should be given to improve the perinatal outcome once the prenatal diagnosis is made.

Adult↗

The relationship between health locus of control and compliance of hemodialysis patients.

Successful treatment of end stage renal disease (ESRD) depends on the patient compliance with therapeutic regimens. This descriptive study was conducted to examine the relationship between the health locus of control (HLC) orientation and compliance with therapeutic regimens. The convenience sample of 86 hemodialysis patients was obtained at two hemodialysis centers of teaching hospitals in southern Taiwan. A Demographic Questionnaire, the Multidimensional Health Locus of Control (MHLC) Scale, and Multimethod Compliance Assessment (including: Laboratory Assessment, Nurse Assessment, and Patient Self-report) were used to collect the data. The average overall rate of compliance with therapeutic regimen was 76.4% by patient self-report and 69.2% by nurse assessment. Examining the three compliance measures, patients were most compliant in following instructions for taking phosphate-binding medication (PBM) and least compliant in limiting fluid intake according to patient self-report and by nurses' assessment. The level of compliance for diet restriction fell between the other two measures. No significant correlations between the three subscales of the multidimensional health locus of control (MHLC) and composite compliance measures were found in this study, except that those with a high score on the subscale of powerful others locus of control were positively correlated with patient self-report (r = 0.388, p < 0.001) and with the laboratory assessment (r = 0.21, p < 0.01). This suggests that the MHLC construct had only a slight influence on measures of compliance in hemodialysis patients of Taiwan. Implications of findings for nursing practice, theory, and research are also discussed.

Adult↗

Obstetrical hysterectomy and placenta previa/accreta: three bladder injury case reports.

Pregnancies complicated with placenta previa and a history of cesarean section are well known to be at increased risk for placenta accreta. Bladder injury is occasionally encountered in these patients during operation. From January 1992 to December 1995, 25 obstetrical hysterectomy were performed at Chang Gung Memorial Hospital, Linkou Medical Center. Of these 25 patients three had bladder injury. Ultrasonography is a unique way to screen and detect prenatally the abnormal placentation and intraplacental lacunae. Color Doppler ultrasonic scanning further discloses that the lacunae are mainly venous spaces. Elevated mid-trimester maternal serum x-fetoprotein (MSAFP) frequently leads to a suspicion of the abnormal placentation, and magnetic resonance imaging (MRI) can clearly identify the placenta accreta/increta. Uncontrollable bleeding frequently occurs in these patients during cesarean section, warranting emergency hysterectomy. Emergency obstetrical hysterectomy should be decided upon and performed by an experienced obstetrician. Massive hemorrhage and bladder injury are the major complications encountered in such operations. We review the literature and propose a protocol of management. As the incidence of cesarean section continues to rise world-wide, the problem of placenta previa/accreta is likely to become more common. Obstetricians should be ready to face the late sequelae of today's decision for cesarean section.

Adult↗

Squamous cell carcinoma arising in mature cystic teratoma of the ovary.

Treatment results of 26 patients with squamous cell carcinoma (SCC) arising in mature cystic teratoma of the ovary were analyzed. Four nulliparous patients with stage Ia tumors underwent conservative salpingo-oophorectomy. Following surgery, 2 patients had successful pregnancies. The remaining 7 patients with stage Ia tumors were observed after hysterectomy and bilateral salpingo-oophorectomy. Fifteen patients with stage Ic-IV tumors underwent cytoreductive surgery followed by cis-platinum-based chemotherapy with or without sequential radiotherapy. The mean survival was 63.9 months. The overall actuarial disease-free survival at 2 years was 69%, and by stage was as follows: stage I, 100% (13/13); stage II, 100% (2/2); stage III, 30% (3/10); and stage IV, 0% (0/1). A significant difference in disease-free survival was noted in stage (P = 0.0001). Optimal versus suboptimal operation was associated with a median Kaplan-Meier survival of 65 months versus 34.8 months, with actuarial disease-free survival at 2 years of 60 and 0%, respectively (P = 0.0210). Our study shows that 67% (16/24) of the patients had SCC antigen levels exceeding 2 ng/ml, which by stage was as follows: stage I, 5/11 (45%); stage II, 1/2 (50%); stage III, 9/10 (90%); and stage IV, 1/1(100%). After completion of treatment, all 8 patients with recurrent lesions had reelevated SCC antigen levels in series SCC antigen monitoring. In conclusion, positive prognostic factors of disease-free survival were optimal cytoreduction and lower FIGO stage. We suggest that multimodality therapy, including aggressive cytoreduction followed by cis-platinum-based chemotherapy with or without sequential radiotherapy, is recommended. In addition, we suggest that serum SCC antigen monitoring may be helpful in early detection of cancer recurrence.

Adult↗

Management of perineal endometriosis.

OBJECTIVE: To demonstrate the appropriate diagnosis and management of perineal endometriosis. METHOD: Six patients with perineal endometriosis were diagnosed according to their clinical symptoms and signs which included cyclic perineal pain and a tender perineal mass coinciding with the menstrual cycle. Diagnostic tools used included ultrasonography, computerized tomography, fine needle aspiration cytology and laparoscopy. Management comprised both surgical and medical treatment. Postoperative follow-up was carried out at 3-monthly intervals. RESULTS: All six patients were cured following surgical excision of the endometrioma. CONCLUSION: A detailed history, thorough pelvic examination and sonographic investigation are essential in diagnosing perineal endometriosis. The role of other diagnostic tools remains controversial. Treatment of extrapelvic endometriosis includes surgical intervention and hormonal suppression. If hormonal suppression fails, surgical excision of the perineal endometrioma should be carried out.

Adult↗

Electronic maps for terminal area navigation: effects of frame of reference and dimensionality.

Two experiments are reported that contrast rotating versus fixed electronic map displays, which pilots used for a simulated approach to a landing. In Experiment 1, a rotating versus fixed-map display was experimentally crossed with a two-dimensional (2D) versus three-dimensional (3D) view (perspective map) as pilots' ability to maintain the flight path and demonstrate awareness of the location of surrounding terrain features were assessed. Rotating displays supported better flight path guidance and did not substantially harm performance on terrain awareness tasks. 3D displays led to a substantial cost for vertical control but did not differ from 2D displays in lateral control. In Experiment 2, pilots flew with the rotating 2D display and with an improved version of the rotating 3D display, designed to reduce the ambiguity of representing altitude information. Vertical control improved as a result of the 3D display design improvement, but lateral control did not. The results are discussed in terms of the costs and benefits of presenting information in 3D, ego-referenced format for both flight path control and terrain awareness.

Aerospace Medicine↗

Endometriosis in adolescent women.

With the aim of determining an effective therapy for adolescent women with endometriosis, the authors analyzed the results of laparotomy performed on 16 cases of female teenagers over a seven-year period. All patients, whose average age of menarche is 12.8, were diagnosed with endometriosis between two months and nine years after the menarche, with an average interval of 5.2 years. The chief symptoms are dysmenorrhea, pelvic pain and abdominal fullness. Of the three patients of unicornuate uterus with rudimentary horn, endometriosis was found only involving the adnexa on the side of the rudimentary horn, two of the three patients had absence of affected side kidney. Conservative operation including six cases of salpingo-oophorectomy and 10 cases of ovarian cystectomy were chosen followed by danazol treatment. One year to seven years after surgical treatment, two patients required subsequent conservative operation for recurrence of endometriosis and two other patients resumed dysmenorrhea. Two married women became pregnant 5 and 10 months after surgical and medical therapy respectively. In conclusion, adolescent endometriosis may occur around five years after menarche and an obstructive uterine anomaly, enhancing retrograde menstruation, increases the occurrence rate. The symptoms and treatment of endometriosis in teenage group do not really differ from that in the older women. In the treatment of endometriosis and for the prevention of recurrence, it is recommended to give three to six months of danazol after surgical treatment.

Adolescent↗