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Biomedical subjects

K J Yu

Publications and source records attributed to K J Yu.

17 recordsLinked to original sources
PubMed2001

Differentiation of glial cells and motor neurons during the formation of neuromuscular junctions in cocultures of rat spinal cord explant and human muscle.

Motor axons extending from embryonic rat spinal cord explants form fully mature neuromuscular junctions with cocultured human muscle. This degree of maturation is not observed in muscle innervated by dissociated motor neurons. Glial cells present in the spinal cord explants seem to be, besides remaining interneurons, the major difference between the two culture systems. In light of this observation and the well documented role of glia in neuronal development, it can be hypothesized that differentiated and long-lived neuromuscular junctions form in vitro only if their formation is accompanied by codifferentiation of neuronal and glial cells and if this codifferentiation follows the spatial and temporal pattern observed in vivo. Investigation of this hypothesis necessitates the characterization of neuronal and glial cell development in spinal cord explant-muscle cocultures. No such study has been reported, although these cocultures have been used in numerous studies of neuromuscular junction formation. The aim of this work was therefore to investigate the temporal relationship between neuromuscular junction formation and the differentiation of neuronal and glial cells during the first 3 weeks of coculture, when formation and development of the neuromuscular junction occurs in vitro. The expression of stage-specific markers of neuronal and glial differentiation in these cocultures was characterized by immunocytochemical and biochemical analyses. Differentiation of astrocytes, Schwann cells, and oligodendrocytes proceeded in concert with the differentiation of motor neurons and neuromuscular junction formation. The temporal coincidence between maturation of the neuromuscular junction and lineage progression of neurons and glial cells was similar to that observed in vivo. These findings support the hypothesis that glial cells are a major contributor to maturity of the neuromuscular junction formed in vitro in spinal cord explant-muscle cocultures.

ATP-Binding Cassette Transporters↗
PubMed2001

Spontaneous expulsion of a uterine submucosal leiomyoma after administration of a gonadotropin-releasing hormone agonist.

A 40-year-old primigravida presented with acute urine retention. Ultrasound examination revealed a large uterine submucosal leiomyoma and GnRH-a was administered. The leiomyoma grew to over twice its original size and protruded through the introitus. After 10 days, it was expelled completely and removed by resectohysteroscopy. The expulsion of the leiomyoma was most likely a result of GnRH-a's flare-up effect.

Adult↗
PubMed2001

Major complications of operative and diagnostic laparoscopy for gynecologic disease.

STUDY OBJECTIVE: To compare complication rates of diagnostic and operative laparoscopy. Design. Retrospective study (Canadian Task Force classification II-2). SETTING: One medical center and three teaching hospitals. PATIENTS: Six thousand four hundred fifty-one women with various indications for laparoscopic diagnosis and/or laparoscopic surgery from January 1994 through June 1999. INTERVENTION: Diagnostic and operative laparoscopies. MEASUREMENTS AND MAIN RESULTS: Forty-two major complications occurred that directly resulted in one death. One patient had stomach injury, 3 had major vessel injuries, 5 had ureter injuries, 10 had intestinal injuries, and 23 had bladder injuries. The overall complication rate for all laparoscopies was 0.65% (42/6451); however, it rose to 0.80% (39/4865) for operative laparoscopy compared with 0.19% for diagnostic laparoscopy (3/1586; p <0.001, Fisher's exact test). CONCLUSION: Laparoscopic surgery is appropriate for managing various gynecologic diseases and has an acceptable complication rate. However, operative laparoscopy should be performed carefully because its rate of complications is significantly higher than that of diagnostic laparoscopy, especially for laparoscopic-assisted vaginal hysterectomy. (J Am Assoc Gynecol Laparosc 8(1):68-73, 2001)

Catheterization↗
PubMed2001

Lithopedion.

Lithopedion is a rare obstetrical outcome of an undiagnosed and untreated advanced abdominal pregnancy, mostly found incidentally. We present a case of lithopedion. In a 76 year-old female suffering from cervical neoplasm, total abdominal hysterectomy was performed for the lesion and the lithopedion was found incidentally. The patient's history was unremarkable, and laboratory tests were normal. The patient recalled having experienced a severe abdominal pain about 50 years before. Her physician had felt "a benign tumor" in her pelvis at that time, indicating that the stone child had retained in the maternal peritoneal cavity for 50 years.

Female↗
PubMed1999

Malignant mixed mesodermal tumor presenting as metastatic lymph node adenosquamous cell carcinoma: a case report.

A solitary inguinal lymph node metastasis from a poorly differentiated adenosquamous cell carcinoma of unknown origin in a 52-year-old female is described. The patient was reported to have had a 2-cm palpable mass in the left inguinal area for three years. She had made regular annual clinic visits for Pap smears since the age of 45 years. Her last visit was eight months prior to a complaint of progressive abdominal distention and dull pain of three months' duration. Physical examination showed a huge pelvic mass, and ultrasound and magnetic resonance imaging of the abdomen showed a 12-cm complex solid mass on the left ovary. The patient underwent a complete excisional biopsy of the left inguinal lymph node. Frozen section pathology revealed a poorly differentiated adenosquamous cell carcinoma. Exploratory laparotomy immediately followed pathologic confirmation of malignancy of the left inguinal lymph node. Complete surgical staging including abdominal cytology, total abdominal hysterectomy, bilateral salpingo-oophorectomy, infracolic omentectomy, retroperitoneal lymph node sampling and excisional biopsy was performed for all suspicious lesions. Stage IIIC malignant mixed mesodermal tumor (MMMT) was diagnosed due to positive left inguinal lymph node metastasis. However, the retroperitoneal lymph node and intra-abdominal cavity did not show spread of the tumors, except those confined to the left ovary with adhesion to the cul-de-sac, and sole lymph node metastasis in a left inguinal lymph node. Although we could not prove that the left inguinal lymph node metastasis had been present for the three years that it was palpable without histologic confirmation, we believe that any enlarged inguinal lymph node might be the first hint of underlying malignancy in the pelvic area, lower extremities or perineal area. In cases of a poorly differentiated carcinoma of inguinal lymph nodes of unknown origin, the abdomen should be carefully evaluated.

Carcinoma, Adenosquamous↗
PubMed1999

Urethral diverticulum presenting with chronic pelvic pain: a case report.

Urethral diverticula are rarely encountered in the gynecologic out-patient setting. However, this condition probably occurs more frequently than it is diagnosed. The patient frequently notes signs of lower urinary tract irritation. Urinary dribbling accompanied with dyspareunia and dysuria constitutes a classic triad for urethral diverticula. Symptoms of chronic pelvic pain only occur in a minority of patients. We report a case of urethral diverticulum presenting chiefly with chronic pelvic pain. The patient underwent multiple investigative operations before a correct diagnosis was made. When confronted with a patient presenting with chronic pelvic pain, a gynecologist should retain a high index of suspicion for a urethral diverticulum in addition to other gynecologic conditions.

Chronic Disease↗
PubMed1998

Tamoxifen-mediated anti-cellular effect against a choriocarcinoma cell line.

The present study was undertaken to evaluate the efficacy of using steroid hormone antagonists tamoxifen and Ru486 for chemotherapy or chemoprevention of choriocarcinoma or other less malignant gestational trophoblastic diseases (GTDs) such as invasive mole. Using 4 trophoblast cell lines, we have shown that tamoxifen (>/= 2 microM) has anti-growth activity on the choriocarcinoma cell line BeWo but not on the other cell lines in a time and dose dependent manner while Ru486 invariably had no detectable effect. Based on a radioimmunoassay, we have been able to detect low levels of estrogen receptors on BeWo (6 +/- 0.4 fm/mg; Kd=438+/- 73 pM) and JEG-3 (6.55 +/- 1.2 fm/mg; Kd=710 +/- 42 pM) cells and progesterone receptors on HT (48.62 fm/mg; Kd=1,690 +/- 182 pM) and TL (8.46 fm/mg; Kd=1,540 +/- 115 pM) cells. However, there is no definite correlation between steroid responsiveness and the presence of the receptors. The mechanism of our observed tamoxifen-mediated anti-cellular effect is uncertain and characteristics commonly associated with apoptotic cell death were not observed. The level of neither wild-type nor mutant forms of the p53 protein correlated with sensitivity to tamoxifen. Our results suggest that estrogen may be a growth hormone for some trophoblasts and tamoxifen may be potentially useful for the treatment of selected cases of choriocarcinoma or other trophoblastic diseases.

Cell Line↗
PubMed1998

High resistance index of Doppler ultrasound in tuberculous peritonitis presenting as abdominal carcinomatosis: report of two cases.

The radiologic features of tuberculous peritonitis (TB peritonitis) are seldom reported, and the use of color Doppler ultrasound in the diagnosis of TB peritonitis is even less common. Herein, we present two patients (a 29-year-old woman and a 56-year-old woman) who were evaluated for months of progressive enlargement of the abdomen, poor appetite and weight loss. In both patients, clinical and laboratory examinations suggested carcinoma, except a very high vascular resistance (resistance index 1.0 and 0.89, respectively) of the tumor feeding vessels detected by color Doppler ultrasound. TB peritonitis was finally diagnosed by exploratory laparotomy. Both patients were treated using a four-drug regimen of isoniazid, rifampicin, ethambutol hydrochloride and pyrazinamide for nine months and were clinically cured. In conclusion, if color Doppler ultrasound reveals normal ovaries, ascites containing thin, delicate incomplete or complete septa, and only a few high-resistance tumor feeding vessels in the abdominal cavity (resistance index > or = 0.80), TB peritonitis should be considered.

Abdominal Neoplasms↗
PubMed1998

Small cell carcinoma of the cervix: analysis of clinical and pathological findings.

PURPOSE OF INVESTIGATION: An attempt to better identify small cell carcinoma of the cervix and evaluate its prognosis. METHODS: From January of 1970 to March of 1995, a total of seven patients diagnosed with small cell carcinoma of the cervix by pathologic revision were retrospectively reviewed. Clinical information including age, clinical stage, lymph-vascular space invasion, lymph node metastases, prognoses were analyzed. RESULTS: All specimens stained positive for neuron-specific enolase (NSE) and four were positive for chromogranin (CGR). The majority of patients (71%) died of disease within 18 months. Only one patient had an abnormal Pap smear before definite diagnosis, and only one patient was well and alive after a combination of surgery and multi-agent chemotherapy (p<0.05). CONCLUSION: Pap smears may not be an appropriate screening method for detecting small cell carcinoma of the cervix. Immunohistological staining may be helpful in diagnosis of small cell carcinoma of the cervix. Because of a very poor prognosis, more effective therapeutic protocol should be further defined in the management of cervical small cell carcinoma.

Adult↗
PubMed1998

Ovarian surgery during pregnancy and puerperium: twelve-year experience at the Veterans General Hospital-Taipei.

BACKGROUND: This study was performed in order to assess the surgical effects and characteristics of ovarian tumors during pregnancy and analyze their prognosis. METHODS: Between 1982 and 1993, 121 patients who had undergone ovarian surgery during pregnancy or puerperium were reviewed at the Veterans General Hospital-Taipei. These patients were analyzed with particular emphasis on the length of gestation at the time of surgery, complications related to the stage of pregnancy, surgical and pathologic findings and the outcome of pregnancy. RESULTS: Ovarian tumors were commonly detected during the second trimester (54.5%) and most of them (79.3%) were asymptomatic. The pathologic review found 38 patients (31.4%) with benign teratoma, 16 patients (13.1%) with corpus luteum and four patients (3.3%) with malignancy. There was a significant difference between emergent ovarian surgery and elective ovarian surgery in the spontaneous fetal wastage rate (14.1% vs 1%, p = 0.009). Compared with elective surgery, cases necessitating oophorectomy, with or without salpingectomy, increased significantly during emergency surgery (57% vs 36%, p = 0.03). All ovarian surgeries performed before a gestational age of seven weeks resulted in spontaneous fetal wastage. CONCLUSIONS: Although the majority of the ovarian tumors detected during pregnancy were benign, emergency laparotomy was sometimes required, which led to an increase in the risk of a fetal wastage. Preconception counseling should be emphasized because early removal of non-functional ovarian tumor before conception, especially teratoma, would decrease the incidence of ovarian surgery during pregnancy. Furthermore, elective and well-prepared surgical intervention appears to be a crucial factor for favorable pregnancy outcome.

Adult↗
PubMed1995

Imaging of immobilized antibody layers with scanning electrochemical microscopy.

Visualization of immobilized antibodies can be achieved with scanning electrochemical microscopy (SECM) by saturation of the antigen binding sites with an alkaline phosphatase-antigen conjugate, which catalyzes hydrolysis of the redox-inactive 4-aminophenyl phosphate to the redox-active 4-aminophenol (PAP). PAP was detected in the collection mode at an amperometric SECM tip. The tip current reflects the density of active binding sites in the immobilized antibody layer. The application of this approach for immunosensing research has been demonstrated with the optimization of a covalent immobilization procedure of antibodies on glass. The special advantages and present limitations of the procedures are discussed.

Antibodies, Monoclonal↗
PubMed1995

Production of a monoclonal antibody to an antigen present on both trophoblasts and leukocytes.

In the present study, we report the establishment of a monoclonal antibody (Mab) designated F10 that recognized an antigen commonly shared by human trophoblasts and leucocytes. F10 MAb was obtained using cell membrane components from a trophoblast cell line HT as immunogen. Based on immunochemical studies, the F10 reactive antigen (F10-Ag) could be located on both villous and nonvillous trophoblasts from early and term placental tissues and on all trophoblastic cell lines. In addition, flow cytometry revealed that most ( > 95%) peripheral blood lymphocytes, monocytes, as well as polymorphonuclear leukocytes (PMN) were positively stained with F10 MAb. Immunoblotting with F10 MAb identified two protein bands with apparent molecular mass of 62 and 56 kDa. Furthermore, the antigens were glycoproteins and were glycosylated via the O-linkage. Scatchard plot analyses of the binding data between 125I-labeled MAb F10 IgG and HT cells revealed a single class of F10 binding sites with an apparent dissociation constant (Kd) of 10.54 +/- 2.03 pM and maximum binding-site (Bmax) value of 2.1 +/- 0.11 x 10(6) sites per cell. We suggest that F10 may be useful for the identification of a novel epitope that is commonly shared by all trophoblasts and leukocytes and such an epitope may be potentially active in maternal-fetal interactions.

Antibodies, Monoclonal↗
PubMed1991

Chemosensitivity testing of an ovarian cancer cell line: comparison of MTT assay and [3H]-thymidine incorporation.

Chemosensitivity test has its role in cancer therapy. Using an accurate, efficient, and simple way to choose the proper chemosensitive drugs in our clinical study will help advance our work. The MTT assay is a rapid, precise, and new method to perform drug sensitivity assay. We used an ovarian cancer cell line (OC-3L-VGH) to compare the accuracy of the MTT and the [3H]-TdR incorporation assay in measuring chemosensitivity of 7 anticancer drugs. Good correlation was observed between the MTT and the [3H]-TdR assay for drug sensitivity testing (r = 0.893, P less than 0.001). Based on this study we found it may be preferable to use the MTT assay for chemosensitivity screening.

Drug Screening Assays, Antitumor↗
PubMed1989

[Determination and analysis of some serum trace elements of active pulmonary tuberculosis].

The concentration of serum Zn, Ca, Cu, Mg in 72 cases of active pulmonary tuberculosis group (including 60 cases with treatment and 12 without treatment) and in 43 cases of healthy group were determined. The results showed that the tuberculosis patients have a decrease of Ca and increase of Cu. There is a reduction of Zn after treatment. There are notable differences of the serum Ca, Cu and Zn content between the tuberculosis and the healthy group, while the difference of Mg is not remarkable. The above results could be used to reveal the regularity of serum element change in tuberculosis and to seek a new clue to the occurrence and treatment of this disease.

Adolescent↗
PubMed1989

Leiomyosarcoma of uterus: a review of 14 cases.

A detailed clinicopathologic study of 14 patients with leiomyosarcoms of the uterus was made. Twelve of 14 patients were followed up for 2 or more years. The median age was 49, the youngest patient was 20, and the oldest was 68. The predominant symptoms were abnormal vaginal bleeding and abdominal pain. The preoperative dilation and curettage established the correct diagnosis was 2 of 6 patients (33%). The predominant method of treatment was total abdominal hysterectomy (TAH). Five patients had adjuvant chemotherapy, 4 had adjuvant radiotherapy, 2 patients had chemotherapy and radiotherapy for adjuvant treatment, and one had adjuvant hormonal therapy. The overall cumulative probability of survival rate at 5 years was 29.6%. The mitotic count, margin type, tumor size, and the presence of necrosis did not affect the prognosis. Favorable prognostic features are low pleomorphism, lower staging, and aggressive management.

Adult↗