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Biomedical subjects

C F Yen

Publications and source records attributed to C F Yen.

At least 37 records · Page 2Linked to original sources
PubMed2000

Laparoscopic-assisted vaginal myomectomy.

STUDY OBJECTIVE: To evaluate the safety and efficacy of combined laparoscopic and vaginal approach in dealing with uterine myomas. DESIGN: Retrospective case study (Canadian Task Force classification II-2). SETTING: Tertiary care major teaching hospital. PATIENTS: Thirty-one women with symptomatic fundal and/or posterior wall uterine myomas. INTERVENTION: Laparoscopic-assisted vaginal myomectomy performed by one of the authors from July 1996 to December 1998. MEASUREMENTS AND MAIN RESULTS: Mean +/- SD operating time, blood loss, and length of hospital stay were 79.19+/-18.31 minutes, 150.00+/- 103.28 ml, and 3.10+/-0.75 days, respectively. No patients developed serious complications, and only two minor complications occurred. CONCLUSION: After laparoscopic inspection and location of uterine myomas, dealing with posterior and fundal uterine myomas by the vaginal route makes hemostasis and uterine repair easier than by purely laparoscopic approach.

Adult↗
PubMed2000

Laparoscopic extraperitoneal sacrospinous suspension for vaginal vault prolapse.

BACKGROUND: A new laparoscopic sacrospinous suspension procedure is described for the correction of vaginal vault prolapse using an extraperitoneal approach. This is the first report in the literature of the extraperitoneal approach. METHODS: We reviewed 12 women who had been treated in our hospital using this technique because of vaginal vault prolapse. These women had undergone hysterectomies (10 abdominal; 2 vaginal) between 5 and 22 years previously (mean, 12 years). After pre-laparoscopic preparation, a 10-mm trocar with a 10-mm zero-degree telescope was placed into the Retzius space. Using a direct air-distended method with a 20 mmHg insufflation pressure, Retzius and para-rectal spaces were created. The sacrospinous ligament could be easily identified and confirmed. A permanent suture was then inserted from the sacrospinous ligament to the vaginal vault to ensure that there was no space in between. RESULTS: This procedure was followed for all 12 patients. There were no major complications during surgery. Eleven women had no recurrence of vaginal vault prolapse during a follow-up period of 1 to 3 years (mean, 2.2 years). One patient developed recurrent vaginal vault prolapse; however, she subsequently underwent a successful colposacropexy by laparoscopy 23 months after the initial surgery. CONCLUSION: We modified the traditional sacrospinous fixation laparoscopically, following principles to restore the correct anatomic position of the vault. Laparoscopic extraperitoneal sacrospinous suspension can eliminate the procedure of opening and closing the peritoneum and avoid interference with the intestine during surgery. It can be used as an alternative to traditional genital suspension surgeries.

Aged↗
PubMed1999

Endoscopic management of injured bowel using the automatic stapler.

Bowel injury is a rare but potentially fatal complication of laparoscopy if it is unrecognized at the time of the procedure. Once a bowel injury is identified, it must be repaired by either laparoscopy or laparotomy. The Endo GIA 30 stapler is effective for achieving large-vessel hemostasis and facilitating laparoscopic procedures, and is reported safe for laparoscopic hysterectomy. It was used successfully in two women to repair extensive bowel injuries.

Adult↗
PubMed1999

Laparoscopically assisted full thickness skin graft for reconstruction in congenital agenesis of vagina and uterine cervix.

In patients with agenesis of the vagina and cervix but with a functional endometrium, the traditional treatment is hysterectomy with construction of a neovagina. We report successful treatment by laparoscopically assisted full thickness skin graft for reconstruction in a patient with congenital agenesis of the vagina and uterine cervix concomitant with haematometra and ovarian endometrioma in a 12 year old girl. Postoperatively, the vaginal skin graft healed well, and menstruation first appeared 4 weeks later. In our opinion, a combined laparoscopic and vaginal procedure with full thickness skin graft is an efficacious alternative in managing such genital defects.

Cervix Uteri↗
PubMed1999

Laparoscopic management of an ectopic pregnancy in a previous Caesarean section scar.

A case of laparoscopic management of an ectopic pregnancy in a previous Caesarean section scar is reported. A 30 year old woman was admitted to our hospital for profuse vaginal bleeding 2 weeks after an abortion had been performed. A urine pregnancy test was positive. Abdominal ultrasound revealed a well-encapsulated bulging mass over the lower anterior uterine wall measuring 7x5 cm. Hysteroscopy revealed retained gestational tissue in the lower corpus despite a normal uterine cavity. An incision was made over the most prominent area of the mass by operative laparoscopy. Dark reddish tissue suggestive of the products of conception was removed using grasping forceps. One-layer of continuous endoscopic sutures along the affected uterine wall was made with 1-0 Prolene. Laparoscopy enabled the successful treatment of an unruptured ectopic pregnancy in a previous Caesarean scar and made it possible to preserve the patient's reproductive capability.

Adult↗
PubMed1999

Laparoscopic hemi-hysterectomy in treatment of a didelphic uterus with a hypoplastic cervix and obstructed hemivagina.

Maldevelopment of the Müllerian duct system may result in various urogenital anomalies including didelphic uterus with a hypoplastic cervix and obstructed hemivagina. We report a patient with this anomaly who was treated by laparoscopic hemi-hysterectomy and hysteroscopic resection of hemivagina. A 17 year old patient who had complained of vaginal pus-like discharge on and off for 1 year was diagnosed by MRI to have a double uterus with obstructed right hemivagina and ipsilateral renal agenesis. After hysteroscopic identification of hypoplasia of the right uterine cervix, laparoscopic resection of the right uterus and right Fallopian tube and hysteroscopically assisted resection of the vaginal septa were performed successfully. From our experience, combined laparoscopy and hysteroscopy may be an efficacious alternative in the management and diagnosis of Müllerian anomalies.

Adolescent↗
PubMed1999

Vaginoscopy using hysteroscope for diagnosis of vaginal bleeding during childhood: case report.

Vaginal bleeding is an uncommon and alarming symptom for children, and serious underlying causes should be excluded. Though vaginal bleeding during childhood was mostly associated with precocious puberty, the physician should keep in mind that local vaginal lesions such infectious vaginitis, vaginal trauma, and vaginal foreign bodies frequently present vaginal bleeding. A 10-year-old girl who denied any traumatic injuries or sexual abuse presented with profuse vaginal bleeding. She had normal development milestones and had no signs of thelarche or adrenarche. Her hymen was intact and the basal measurements of sex hormones including tyrotropic hormone and thyroxine were all within reference ranges. Finally, a laceration of the vaginal wall was found by vaginoscopy using a hysteroscope under general anesthesia and treated using gauze packing. We must emphasize the importance of vaginoscopy and examination under anesthesia in a child with vaginal bleeding to exclude local vaginal lesions. In addition, vaginoscopy using a hysteroscope makes the examination efficient and cost effective.

Child↗
PubMed1999

A huge 6.2 kilogram uterine myoma coinciding with omental leiomyosarcoma: case report.

Surgery for massive abdominal tumors is both interesting and challenging. We present a case involving a multiple uterine myoma weighing 6.2 Kg which coincided with omental leiomyosarcoma. To our knowledge, this is the first report of this type of condition in the English literature. A 44-year-old nulliparous woman had suffered from abdominal pain for a long time. A huge abdominal mass was palpated on physical examination. Computed tomography scanning revealed a huge pelvic-abdominal mass with the possibility of small bowel loops invaded by the mass. A 6-cm omental mass was incidentally found during the subsequent hysterectomy procedure. Perforation of the urinary bladder occurred during the dissection of adhesion. Resection of the omental mass, wide wedge resection of the invaded small bowel, primary repair of the bladder, and hysterectomy were performed. The final pathologic diagnosis was uterine leiomyomata with omental leiomyosarcoma. The patient returned home on postoperative day 14 and was well at the 18-month follow-up examination. The challenge of these tumors lies in their proper diagnosis and surgical management. More case reports and follow-up studies are needed to confirm the efficacy of their management.

Adult↗
PubMed1998

Apoptosis may be either suppressed or enhanced with strategic combinations of antineoplastic drugs or anti-IgM.

A variety of drugs have been used to treat B-lymphocyte neoplasms, including both cell cycle-specific (CCS) and non-cell-cycle-specific drugs. Although the therapy for such cancers is complex and can include both types of drugs, the efficacy of these drugs in inducing cell death remains unclear. In this paper we have concentrated on specific CCS drugs and have examined their ability to induce programmed cell death (apoptosis) in Burkitt's lymphoma cell lines derived from patients. The CCS drugs chosen were hydroxyurea and aphidicolin (active in late G1, early S phase), the topoisomerase poisons camptothecin and etoposide (S, early G2 phase) and vincristine and Taxol (late G2, M phase). These choices allow comparison of two drugs with differing modes of action for each of the various phases of the cell cycle. Our results indicate that the variation in apoptosis between drugs that act at the same phase of the cell cycle is negligible. Both S/G2 and G2/M blockers are very potent at inducing apoptosis whereas G1/S blockers are ineffective in the induction of apoptosis. In addition, marked kinetic variations in the rate of apoptosis induction were observed, etoposide and camptothecin being more rapid in their action than the other agents. The order of effectiveness in inducing apoptosis on a kinetic basis was S/G2 agents >> G2/M agents >> G1/S agents. In this study we have also found that growth inhibition was induced by all the CCS agents chosen and by anti-IgM in various Burkitt's lymphoma lines. Furthermore c-myc was down-regulated under similar conditions. Since apoptosis was only selectively induced by some of the CCS agents, it implies c-myc expression is associated with growth regulation and c-myc down-regulation is an insufficient condition for the induction of apoptosis. In addition, cotreatments using the CCS and other agents revealed the following: Cotreatment using two CCS drugs which act at the same stage in the cell cycle showed either no change or only additivity to the effects seen with either agent alone. However, cotreatment with CCS drugs showed that an inhibitory effect is found between G1/S and G2/M drugs or S/G2 and G2/M drugs. No effect was found between G1/S and S/G2 drugs. Anti-IgM, which by itself was capable of inducing apoptosis, was observed to augment apoptosis induced by very low concentrations of G2/M-acting drugs but it has little effect on G1/S or the S/G2 drugs. The inhibitory effect of anti-CD40 or TNF-alpha on anti-IgM-induced apoptosis did not carry over to an effect on apoptosis induction by the CCS agents. Thus specific combinations of agents may lead to either enhancement, inhibition, or no interactive effect on apoptosis.

Antibodies, Anti-Idiotypic↗
PubMed1997

Anti-IgM-induced growth inhibition and apoptosis are independent of ornithine decarboxylase in Ramos cells.

Ornithine decarboxylase (ODC) is a key enzyme involved in polyamine production and is thought to regulate growth and apoptosis in multiple cell systems. A potential link between ODC and growth may involve the action of an oncogene c-myc which is thought to transcriptionally regulate ODC. We have examined the involvement of ODC in anti-IgM-induced growth inhibition and apoptosis in Burkitt's lymphoma cells. Inhibitors of ODC such as difluoromethylornithine (DFMO) completely blocked ODC activity, resulting in growth inhibition but not apoptosis. Addition of putrescine, the product of ODC enzymatic action, to Ramos cells had only a minor effect on growth, did not cause apoptosis, did not augment or block anti-IgM-mediated growth inhibition and apoptosis, but did reverse DFMO-mediated growth inhibition. Anti-IgM treatment of Ramos cells, which markedly decreased c-myc mRNA and protein, caused a paradoxical increase in ODC mRNA level as well as ODC enzymatic activity and increased cellular levels of putrescine. DFMO and putrescine did not alter c-myc mRNA levels directly, nor did they have any affects on anti-IgM-mediated down-regulation of c-myc mRNA. TNF-alpha, which inhibited anti-IgM-mediated apoptosis, did not inhibit either anti-IgM or DFMO-mediated inhibition of growth. These agents were without effect on ODC activity itself or on the anti-IgM-mediated increase in ODC activity. From these studies we conclude that ODC inhibition affects growth but is unrelated to the induction of apoptosis. Both anti-IgM-mediated inhibition of growth and induction of apoptosis are independent of ODC. Thus two distinct pathways for growth regulation are present: one in which ODC and polyamines are important and the other cell surface receptor-mediated (sIg) which is independent of ODC and polyamines.

Apoptosis↗
PubMed1997

The binge eating and emotional change in a patient with postinfectious encephalomyelitis.

Postinfectious encephalomyelitis is a kind of demyelinating disease with pathological characteristics and a monophasic clinical course. Herein, we describe a patient who had the symptoms of binge eating, fatigue, memory impairment, hypotalkativeness, hypoactivity, lethargy, incoherent speech, dysphoric mood, and episodic disorientation. Only elevation of CSF protein was noted upon initial admission; however, blurred vision of the eyes developed progressively after discharge. A magnetic resonance image (MRI) scanning of the brain demonstrated scattered lesions of low signal intensity on T1-weighted images and high areas on T2-weighted images in the left thalamus, bilateral hypothalamus and midbrain. The findings of MRI image, CSF, and clinical course all suggested postinfectious encephalomyelitis. After a treatment of prednisolone, a follow-up MRI revealed evidence of improvement, and the binge eating also improved.

Adult↗
PubMed1997

The psychiatric manifestation of Creutzfeldt-Jakob disease.

Creutzfeldt-Jakob disease (CJD) is considered to be very rare in the population, and the psychiatric manifestation of the disease even rarer with only one report in the past few years in Taiwan. To clarify whether the psychiatric manifestation of CJD is really rare or whether it is neglected in Taiwan, the authors reviewed the discharge notes of patients who had been admitted to a neurological unit in the past 15 years and conducted a chart review of the patients of CJD supported by the clinical courses, EEG finding and brain biopsies. An inquiry was made by telephoning their families to follow up their condition after discharge. Five of the 8 cases with CJD had psychiatric symptoms including changes of mood, thought, behavior and perception during their course of illness. Four cases had been sent to the psychiatric unit and received treatment under several kinds of psychiatric diagnoses. Two patients had been admitted to the psychiatric unit and one had received electroconvulsive treatment. Two of the patients had been suspected to be the victims of neuroleptic malignant syndrome. It is likely that it is psychiatrists who will meet CJD patients first in the early stages of disease. CJD should be kept in mind and EEGs with detailed neurological checkups should be completed, if the cognitive functions of the patients with unusual neurological symptoms deteriorate quickly and their psychiatric symptoms fail to respond to any treatment.

Aged↗
PubMed1997

Severe granulocytopenia secondary to chlorpromazine despite concurrent lithium treatment: a case report.

Severe chlorpromazine-induced granulocytopenia where the white-cell count decreases to below 1,000/mm3 rarely occurs and lithium is known to cause leucocytosis. The use of lithium in the prevention of granulocytopenia induced by drugs is still controversial. This report describes a patient with bipolar disorder suffering from severe granulocytopenia and severe respiratory infection after receiving chlorpromazine 50 to 150 mg per day along with long term lithium therapy. Bone-marrow aspiration and biopsy revealed inhibited maturation of myeloid series in the promyelocyte stage. The findings were consistent with a drug-induced effect. White-cell count return to normal after the discontinuation of chlorpromazine. It was proved in this case that combined lithium therapy had no effect in preventing agranulocytosis induced by chlorpromazine.

Aged↗
PubMed1996

Intestinal absorption studies on peptide mimetic alpha-methyldopa prodrugs.

Two dipeptide mimetic prodrugs, 1 and 2, and two tripeptide mimetic prodrugs, 3 and 4, of L-alpha-methyldopa were evaluated for intestinal absorption by in-situ single pass rat jejunal perfusion studies and by in-vitro uptake experiments in brush-border membrane vesicles (BBMVs) prepared from rat intestine. In the perfusion studies, compound 1 demonstrated a 3.5-fold increase in permeability (Pm* = 2.27) as compared with that of alpha-methyldopa (Pm* = 0.65), indicating that this prodrug was better absorbed in the intestine than its parent drug. Other prodrugs showed no significant improvement in intestinal permeability. The results correlated with the results of BBMV uptake studies. In the presence of an inward proton gradient, compound 1 showed Michaelis-Menton saturable kinetics of BBMV uptake with a low value of K(m) (0.06 +/- 0.13 mM) and a high value of Vmax/K(m)(36.38 nmol (mg protein)-1/30s mM-1) at a low concentration range and a linear uptake at high concentrations with Kd = 0.14 +/- 0.02 mM. Compounds 2 and 3 were mainly taken up in BBMVs via passive diffusion. Compound 4 was taken up in BBMVs basically via the carrier-mediated transport system, while the rate of uptake was much lower than that of compound 1. The uptake of compounds 1 and 4 was significantly inhibited by dipeptides L-Gly-L-Pro and L-Gly-L-Phe, and cephradine, a beta-lactam known to be transported via the dipeptide carrier system, indicating that both compounds were taken up in BBMVs via the H(+)-coupled dipeptide-mediated transport system. In contrast to the complicated uptake profile of alpha-methyldopa, the higher rate of BBMV uptake with less variation demonstrated on compound 1 suggested that the attached nonessential amino acid moiety, D-phenylglycine, is a feasible delivery tool in carrying the parent drug through the intestine.

Animals↗
PubMed1995

Regulation of low-density lipoprotein receptors and assessment of their functional role in Burkitt's lymphoma cells.

The status of low-density lipoprotein receptors (LDLR) in Daudi Burkitt's lymphoma (BL) cells was examined using a flow cytometric assay employing the fluorescent ligand DiI-LDL, and a radioligand-binding assay using [125I]LDL. The binding is concentration-and time-dependent; and is specific, as judged by its competitive displacement in the presence of unlabeled LDL, and inhibition by heparin, EGTA, and 4 degrees C incubation. The regulation of the receptor and its functional role were then explored. Our results suggest the following: (a) In sharp contrast to normal peripheral blood lymphocytes, the LDLR levels in BL cells are basally elevated when cultured in fetal bovine serum (FBS) medium. (b) In accord with normal peripheral blood lymphocytes, incubation in lipoprotein-deficient serum (LPDS) medium further up-regulates the level of the receptor in BL cells, and co-incubation with LDL or 25-hydroxycholesterol down-regulates the receptor level. The magnitude of the up-regulation is significantly smaller than in normal peripheral blood lymphocytes. (c) Northern blots using a plasmid-DNA probe for LDLR mRNA point to a similar pattern for message regulation as is observed in direct binding studies. (d) Although the LDLR level is constitutively high in BL cells, availability of LDL, unlike transferrin, is not a growth requirement since incubation of cells in LPDS medium does not prevent proliferation of these cells. (e) In contrast to anti-transferrin receptor antibody which results in apoptosis upon binding, anti-LDLR antibody does not inhibit growth or induce apoptosis. Our results suggest LDLR is expressed at a significantly higher level in BL cells than in normal peripheral blood lymphocytes. Although up-regulation and down-regulation of LDLR are observed, this applies only to a small population of LDLR. The bulk receptor population is significantly resistant to down-regulation. Furthermore, notable differences in the functional role of the LDLR are found relative to the transferrin receptor which is also up-regulated in the BL cells.

Apoptosis↗
PubMed1994

Flow cytometric evaluation of LDL receptors using DiI-LDL uptake and its application to B and T lymphocytic cell lines.

Low density lipoprotein receptors (LDL-R) on Daudi Burkitt's lymphoma (BL) cells were assessed using fluorescent DiI (3,3'-dioctadecylindocarbocyanine iodide)-LDL and flow cytometric analyses. Receptor-specific binding of DiI-LDL is followed by internalization of the bound complex and lysosomal hydrolysis of the ligand. Increase in the fluorescence intensity per cell is hence used as a measure of DiI-LDL uptake and, implicitly, as an indication of LDL-R presence. Our results show that uptake was observed in > 98% of the Daudi cells, and the level of uptake was significant and clearly distinguishable from autofluorescence, suggesting that: (a) this assay is comparable to the iodinated LDL uptake assay, although the ED50 values for the ligands are different; (b) this assay is comparable to the flow-cytometric detection of LDL-R using a commercial antibody directed against the receptor itself, and superior to a similar assay based on an antibody directed against membrane-bound LDL; (c) LDL uptake could be monitored along with transferrin uptake, suggesting that multiple endocytic receptor activities can be concurrently studied; (d) DiI-LDL uptake can be examined along with fluorescein-conjugated anti-CD10, -CD19, and -CD71, with little cross-interference, offering the added advantage that endocytic uptake and phenotyping can be simultaneously monitored; (e) the expression of LDL-R is intrinsically elevated in diverse cell lines such as Daudi, Raji, Ramos, Jurkat, and WIL2-NS, but not in normal lymphocytes. Our results therefore indicate that flow cytometric analysis of DiI-LDL uptake has potentially useful applications in the detection and study of endocytic receptor LDL-R in B and T lymphocytic cell lines.

B-Lymphocytes↗
PubMed1993

Skeletal effects of withdrawal of estrogen and diphosphonate treatment in ovariectomized rats.

The study was designed to determine the skeletal effects of withdrawal of estrogen and diphosphonate treatment in the estrogen-deplete state. Groups of ovariectomized (OVX) rats were treated with vehicle alone, estrogen, or the diphosphonates etidronate or risedronate for a 180-day period. A group of sham-operated control rats was treated for 180 days with vehicle alone. All treatments were then terminated, followed by sequential sacrifice of rats at 0, 35, 90, 180, and 360 days after withdrawal of treatment. The proximal tibia from each animal was processed undecalcified for quantitative bone histomorphometry. At the end of the treatment period, vehicle-treated OVX rats were characterized by cancellous osteopenia and increased bone turnover relative to vehicle-treated control rats. Treatment of OVX rats with estrogen or diphosphonates depressed bone turnover and protected against cancellous osteopenia. During the withdrawal period, OVX rats previously treated with estrogen exhibited rapid bone loss associated with increased bone turnover. The bone protective effect of the hormone in OVX rats was nearly completely lost by 90 days of withdrawal. In contrast, OVX rats maintained low levels of bone turnover and normal cancellous bone mass at 180 days of withdrawal from diphosphonate treatment. The results suggest that estrogen-deplete women who are withdrawn from estrogen replacement are at high risk for subsequent bone loss. They further suggest that widely spaced periods of intermittent diphosphonate treatment may be sufficient to prevent the development of osteopenia in postmenopausal and oophorectomized women.

Animals↗