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Biomedical subjects

L M Chen

Publications and source records attributed to L M Chen.

117 records · Page 7Linked to original sources
PubMed1979

Implantable artificial capillary unit for pancreatic islet allograft and xenograft.

Implantable artificial capillary units containing approximately 1,200 allogeneic rat islets, or approximately 3,000 xenogeneic rabbit or human islets as an implantable artificial endocrine pancreas (IAEP) were implanted in streptozotocin-induced (55 mg/kg) diabetic rats. A total of 26 rats received IAEP containing allogeneic islets. Twenty were short term experiments which lasted for 12-24 h. Four recipients survived between 1-3 days and the remaining two for 4 and 11 days respectively. Five diabetic rats received IAEP containing xenogeneic islets. The four recipients of IAEP containing rabbit islets survived up to 4 days while the recipient of IAEP containing human islets survived for 8 days. Following implantation, a decrease of plasma glucose from the initial value of 500 mg/dl to normoglycaemia and a corresponding increase in circulating levels of insulin up to 100 muU/ml were observed in the recipient animals. Furthermore the IAEPs were shown to produce a near normal plasma glucose and insulin response to an intravenous glucose tolerance test. These findings suggest the feasibility of achieving amelioration of diabetes with allogeneic or xenogeneic pancreatic islets implanted as an artificial endocrine pancreas unit in the experimental animals which has the potential of future clinical application in man.

Animals↗
PubMed1977

Long-term survival of adult rat islets of langerhans in artificial capillary culture units.

Pancreatic islets from adult rats were cultured in artificial capillary cultury units that were perfused with nutrient medium. In this in-vitro culture system, islets remain functional for at least 97 days. As determined by insulin radioimmunoassay of the culture medium, islets continue to secrete insulin. Furthermore, islets responded to high glucose concentration in the perifusion medium by increased insulin release throughout the duration of the culture period. A normal appearance of individual epitheloid islet cells and the presence of aldehyde-fuchsin-positive granules were observed in islets fixed in medium. As indicated by the prolonged maintenance of tissue-specific function, the present simple technique for organ culture of intact islets should be useful for providing new information on the long-term effects in vitro of various factors on islet function and a means for the preservation of islets for transplantation.

Animals↗
PubMed1976

Response to ACTH and dibutyryl cyclic AMP by enucleated adrenocortical tumor cells.

Y-1-L cells, a subline of the Y-1 functional murine adrenocortical tumor cell line, were enucleated with cytochalasin B and the response of these enucleated cells to ACTH and dibutyryl cyclic AMP (dbcAMP) was examined. Enucleated Y-1-L cells maintained a basal steroid output for at least 24 h and responded to either ACTH (10 mU/ml) or dbcAMP (1 mM) by a change from flat to rounded cell shape, and by increased steroidogenesis. The steroidogenic response of enucleated cells during the first 3 h after enucleation was highly significant and, though it decreased rapidly thereafter, it persisted to a limited degree for up to 12 h. On the other hand, the morphologic change could be induced even at 33 h after enucleation. The results of this study show that the nucleus is not required for the expression of the acute effects of ACTH or dbcAMP and that the cytoplasmic components necessary for cell 'rounding' and a steroidogenic response are stable for 36 h and 12 h, respectively.

Adrenal Cortex Neoplasms↗
PubMedDate not supplied

Recurrent ovarian carcinoma: is there a place for surgery?

The role of cytoreductive surgery is well established in patients with primary ovarian carcinoma. Minimal residual disease translates to improved response to adjuvant treatment and prolonged survival. For close clinical follow-up, different approaches may be helpful in detecting recurrent disease, including regular physical/pelvic examination, serial CA-125 levels, and imaging studies using computerized tomography, magnetic resonance imaging, or positron emission testing. At recurrence, those patients with a good performance status, a good response to primary therapy, and a macronodular tumor distribution pattern may be candidates for a secondary cytoreductive procedure. Data suggests that secondary cytoreduction is superior to chemotherapy alone in patients who have a significant disease-free interval (6 to 12 months). Survival after secondary cytoreduction is optimized with cytoreduction to microscopic disease, yet there is a recognized risk of surgical morbidity. Therefore, a strong relationship between the gynecologic oncology surgeon and the patient is key to obtaining appropriate informed consent and relaying appropriate outcome expectations.

Female↗
PubMedDate not supplied

Epstein-Barr virus early ribonucleic acids as a diagnostic adjunct for relapsed metastatic tumors in patients with cured primary undifferentiated nasopharyngeal carcinoma.

PURPOSE: Epstein-Barr virus (EBV) has been consistently shown to be associated with undifferentiated nasopharyngeal carcinoma (NPC). In this article, the authors attempt to detect Epstein-Barr virus in distant relapsed metastatic sites in undifferentiated NPC patients with cured primary cancer. MATERIALS AND METHODS: In situ hybridization (ISH) technique is a reliable method to detect EBV early RNAs (EBERs) within NPC cells. We used a nonisotopical ISH technique to examine the presence of EBERs in paraffin-embedded tissues obtained from 1 paired specimen of primary NPC and its metastatic counterpart at liver and 2 metastatic specimens of retroperitoneal lymph nodes and bone. RESULTS: All the primary lesions and the metastatic tumors of NPC with undifferentiated histology contained EBERs that could be clearly detected in the nuclei of cancer cells. CONCLUSIONS: This article shows that EBERs can be successfully detected in cells of the distant relapsed metastatic sites. These results suggest that this nonisotopical ISH method of EBERs can be potentially used to diagnose NPC patients developing distant relapsed metastatic lesions with cured primary cancer early. It can offer quick information as to institute suitable salvage chemotherapy for these patients.

Adult↗
PubMedDate not supplied

Primary cecal lymphoma. Report of a case with preoperative diagnosis by fine needle aspiration and immunocytochemistry.

Fine needle aspiration of a cecal mass was performed on a patient with a cecal tumor and iron-deficiency anemia. Cytologic studies of the air-dried smears showed large cell lymphoma. The diagnosis of large cell lymphoma of the B-cell type was affirmed by immunocytochemical studies and at laparotomy and resection of the tumor. Even under unusual circumstances, the diagnosis of such a rare abdominal lesion as primary cecal lymphoma can be made with certainty by cytologic and immunologic studies of fine needle aspirates.

Adult↗