Biomedical subjects
Publications and source records attributed to Y Yao.
On radioisotope scanning, thyroid nodules present one of five characteristic patterns. A "cold" nodule is most likely to be malignant and often necessitates surgery and functional ablation. However, any nodule that is growing and insuppressible probably should be removed.
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The photochemical behaviors of six non-ortho substituted PCB congeners, i.e., 3,4-DiCB, 3,5-DiCB, 3,3',5-TriCB, 3,4,5-TriCB, 3,3',4,5-TetraCB, and 3,4,4',5-TetraCB, irradiated at 254 nm in alkaline 2-propanol were investigated. Besides the determination of the photodechlorination pathways of these compounds, the presence of photorearrangement was observed in the case of 3, 4-DiCB with its products being identified. The results indicate that dechlorination is much more important than rearrangement during the process of PCB photolysis.
Ovarian carcinoma anti-idiotypic antibody 6B11 was murine derived; we previously have cloned 6B11 single-chain Fv antibody (6B11ScFv) and constructed the 6B11ScFv/human granulocyte-macrophage colony stimulating factor (GM-CSF) fusion protein (designated as 6B11GM) to enhance the immunogenecity of the single-chain Ab(2). Because of the difference in species specificity between human GM-CSF and murine GM-CSF, there is no immune competent animal model on which the effect and metabolism of 6B11GM as a vaccine could be observed. In this study, 6B11mGM fusion gene was constructed by the fusing murine GM-CSF cDNA gene with 6B11ScFv. The fusion gene was cloned and expressed. The product of this gene is a fusion protein. It could specifically interact with the primary anti-ovarian carcinoma monoclonal antibody (COC166-9) and rat anti-mouse GM-CSF monoclonal antibody, respectively, and stimulate the growth of NFS-60 cells (a murine GM-CSF-dependent cell line). The specific anti-tumor immune response could be induced in BALB/c mice after immunized with anti-idiotypic fusion protein instead of ovarian carcinoma antigen without carrier proteins and adjuvant. Ab(3) could be detected in the sera of immunized mice with 6B11mGM by enzyme-linked immunoadsorbent assay test. Moreover, the fusion protein stimulated proliferation of CD4+ T cell from the spleen of BALB/c mice and proliferation of CD8+ T cell to a lesser degree. Therefore, 6B11mGM probably induces both humoral and cellular immunity against ovarian carcinoma in vivo.
The molecular events leading to the development and progression of ovarian carcinoma are not completely understood. We performed a large-scale survey for the identification of differentially expressed genes between ovarian carcinoma and normal ovarian tissue by using cDNA microarray analysis. We utilized 512 member human novel putative oncogene and tumor suppressor gene cDNA microarrays to study the differences in gene expression between ovarian carcinoma and normal ovarian tissues. Some differentially expressed genes have been further confirmed by immunohistochemical analysis. A total of 39 differentially expressed genes were identified, of which 16 and 23 were specifically expressed in ovarian cancer and normal ovarian tissue, respectively. The comparison of average signal of differentially expressed genes exhibited at least a twofold difference in expression. The differentially expressed genes may be related to the carcinogenesis and progression of the malignant growth. The use of cDNA microarrays allows simultaneous monitor of the expression of many genes, thereby it speeds up the identification of differentially expressed genes. It is essential for further exploration of the mechanisms of the disease.
We first established a human ovarian sarcomatoid carcinoma cell line designated BUPH:OVSC from primary culture. The specimen was derived from the mural nodule in an ovarian mucinous tumor and cultured in vitro. To date, the cell line has been maintained for over 100 passages. Its biologic characteristics were studied by light and electron microscopy, which revealed spindle-shaped or polygonal cells with a doubling time of 39.5 h. The agglutination test of BUPH:OVSC was positive, and cell colonies were formed in soft agar. Chromosome analysis revealed its karyotype to be a pseudodiploidy. One X chromosome deletion and chromosome 20 addition were detected, and aberrant chromosomes t (1q;12q) and 14p(+) were its chromosome markers. BUPH:OVSC was tumorigenic in nude mice. Hematoxylin and eosin staining of transplanted tumors showed that the cells were morphologically sarcomatoid. However, the transmission electron microscopic observation exposed its epithelial origin. The cell line coexpresses cytokeratin and vimentin. It dose not appear to express estrogen and progesterone receptors or the CA125 tumor marker. Alcian blue/periodic acid-Schiff staining indicates that the cells could secrete acid mucopolysaccharide. In conclusion, BUPH:OVSC displays unique cellular properties, which make it a useful model for the study of human ovarian sarcomatoid carcinomas.
We retrospectively assessed the incidence and time course of enlargement in post-traumatic intracerebral haematoma (PTICH). Computed tomography (CT) scans from 165 patients who underwent a scan within 72 h and a repeat scan within 120 h of the onset of trauma were examined. A semi-automated method using region deformation-based segmentation was used to calculate the haematoma volume. The presence of haematoma enlargement was also determined based on a consensus by five observers. Seventy cases (42%) showed enlargement of the haematoma. The frequency of haematoma enlargement decreased as the interval between the onset of trauma and the initial scan increased. The discriminant value of the ratio of the haematoma volume in the second scan to that in the initial scan was ascertained, and the cut-off value for haematoma enlargement was determined to be 1.45. The radiographic criterion for enlargement in PTICH on CT scan was, therefore, defined as a > or = 1.45 times increase in haematoma volume.
This study investigated the frequency of aspiration pneumonia in conscious stroke patients fed by a family member and examined the effect of introducing training in swallowing techniques by nurses. A total of 96 consecutive patients presenting with dysphagia due to acute stroke were included in the study. Patients presenting between January 2000 and July 2003 (n = 48) were fed orally by a family member given general nursing information (group A), whereas those presenting between August 2003 and March 2005 (n = 48) were fed orally by an experienced nurse trained in specific swallowing techniques (group B). All patients were examined daily for the presence of aspiration pneumonia. The incidence of aspiration pneumonia was 33.3% in group A and 6.3% in group B (P < 0.05). The incidence of aspiration pneumonia in dysphagic stroke patients who are orally fed is still high. Training in swallowing during oral feeding offers clear protection against pneumonia in conscious stroke patients.
The process of terminal differentiation is associated with exit from the cell cycle and loss of the proliferative potential of cells. The cyclin-dependent kinase inhibitors (CDIs) play critical roles in check-point functions during the cell cycle and as inhibitors of cell proliferation. Loss of their activities can impair development and differentiation and contribute to the uncontrolled proliferation characteristic of cancer cells. When the promyelocytic leukemia cell line HL60 is induced to differentiate in vitro, by a variety of agents, cellular levels of the CD1 proteins p21Cip1 and p27Kip1 are increased. To further address the roles of these two proteins in differentiation, we have overexpressed either a human p21Cip1 or p27Kip1 construct in HL60 cells. The overexpression of p21Cip1 accelerated both the monocytic and granulocytic differentiation of HL60 cells triggered by TPA or DMSO, respectively. The accelerated and more dramatic induction of differentiation seen in the p21Cip1 overexpressors was associated with a more rapid reduction of CDK2 kinase-associated activity, increased levels and more rapid dephosphorylation of the Rb protein, and increased levels of the cyclin D3 protein. Stable overexpression of p27Kip1 also enhanced TPA-induced differentiation of HL60 cells. These studies provide direct evidence that the increased expression of p21Cip1 and p27Kip1 play a causal role in the process of terminal differentiation of HL60 cells. Therefore, agents that enhance the expression of one or both of these proteins might be useful in therapy by enhancing the terminal differentiation of leukemia cells.
The nonsteroidal anti-inflammatory drug (NSAID) sulindac and its derivatives induce apoptosis in a variety of carcinoma cells in vitro and display antitumor effects in vivo. The effects of these agents have not, however, been studied in detail in leukemia cells. In the present study we compared the effects of sulindac sulfide to those of 12-0-tetradecanoylphorbol ester (TPA) on the human promyelocytic leukemia cell line HL60. The latter compound is known to induce monocytic differentiation in these cells. We found that both sulindac sulfide and TPA caused growth inhibition, cell cycle arrest in G0/G1 and increased levels of the cell cycle inhibitory proteins p21Cip1 and p27KiP1. However, whereas the TPA treated cells underwent subsequent differentiation the sulindac sulfide-treated cells displayed extensive apoptosis and negligible differentiation. Ectopic overexpression of p21Cip1 or p27KiP1 markedly enhanced the apoptosis induced by sulindac sulfide. Therefore, sulindac sulfide and related compounds may be useful in the treatment of leukemia and other neoplasms, especially when used together with agents that increase cellular levels of p21Cip1 or p27KiP1.
We investigated 5 cases with brain tumors composed ofneuronal and astrocytic differentiated tumor cells occurring in the cerebral hemispheres of adults. Patients ranged from 33 - 69 years of age, 3 females and 2 males. Radiologically, contrast enhancement was demonstrated in these tumors. All tumors were surgically resected following radiotherapy and chemotherapy. Four patients have been free of recurrence for 2-5 years. One recurred 15 years after the operation. Histologically, tumor cells were mainly composed of round or oval nucleate cells with scant cytoplasm and compactly arranged with neurocytic features. Immunohistochemically, some tumor cells were immunoreactive for synaptophysin, neurofilament, beta-tubulin, chromogranin A, GFAP and vimentin. There were little immunoreactive cells for myelin basic protein and epithelial membrane antigen. Ultrastructurally, tumor cells were variably differentiated as follows: undifferentiated cells having prominent nuclei and scanty cytoplasm with inconspicuous organelles; neuronal cells consisting of neurosecretory granules or vesicles and abortive synapses, and astrocytic cells with cytoplasmic intermediate filaments. The Ki-67 labeling index ranged from 4.5 - 9.8%. Allelic loss of chromosome Ip occurred in 2 cases (50%) and allelic loss of chromosome 19q occurred in 2 cases (50%) of 4 informative cases. These tumors were characterized as neuronal and astrocytic differentiated tumors with primitive PNET-like component. However, there was little oligodendrocytic or ependymal differentiation in these tumors.
From November 1986 to January 1993, 97 wrinkled ePTFE prosthetic vascular grafts were implanted in 90 peripheral arterial reconstructions for 87 patients with arteriosclerosis obliterans (ASO) (79 men and 8 women). Grafts used in this series were 54 Vitagraft and 33 Technograft. Initial results for a period of as long as 6 years are summarized here. Forty-four (45.3%) grafts were implanted anatomically, and the remaining were extra-anatomically routed. The mean age of patients in the anatomic bypass group was 64.7 years, and that of patients in the other group was 71.4 years. Twenty-three (43.3%) grafts in the extra-anatomic group were anastomosed sequentially. Mean follow-up periods for each group were 32.4 months and 30.9 months, respectively. None of nine late deaths during the follow-up period was graft related. There was one primary obstruction in the anatomic group; in the extra-anatomic groups, primary graft occlusion occurred in four grafts. In addition, one perigraft seroma and one pseudoaneurysm requiring surgical repair were seen. Cumulative event free ratio for this group was 80.8% at 72 months. These results reveal that the wrinkled ePTFE graft is clinically applicable to arterial reconstruction for ASO with satisfactory long-term patency, even in extra anatomic sequential bypasses.