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Biomedical subjects

J Gao

Publications and source records attributed to J Gao.

At least 523 records · Page 29Linked to original sources
PubMed1982

Characteristics of invasiveness of human nasopharyngeal carcinoma cells in organ culture, as observed by scanning electron microscopy.

Cells of a human nasopharyngeal carcinoma (CNE) were cultured in contact with embryonal mouse heart fragments wrapped in a fibrous kidney capsule as biological permeable membrane. The culture was terminated at different intervals and processed for scanning electron microscopy. Carcinoma cells showed abundant microvilli and filopodia in contact with superficial cells of the heart fragments. Cancer cells appeared firmly attached to the surface of the tissue fragments. Subsequently, malignant cells extended pseudopodia into intercellular spaces of the supporting tissue particle, and beyond the third day of cultivation, cancer cells were also found in deeper parts of the organ. The cancer cells on the surface of the specimen had apparently lost the ability to invade. After a while, microvilli and filopodia decreased in number or adhered to each other. The plasma membrane exhibited signs of degeneration.

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PubMedDate not supplied

Site-dependence of invasiveness of ECA109 human oesophageal carcinoma cells in nude mice.

ECA109 human oesophageal carcinoma cells were injected either subcutaneously or intraperitoneally into BALB/CATc 1-nu/nu mice. After 23 weeks tumours were examined histologically and by scanning electron microscopy. Subcutaneous ECA109 tumours were well-delineated without signs of invasion. By contrast, intra-abdominal tumours invaded into the abdominal wall and abdominal organs. This result provides us with another example of site-dependence of invasion in vivo.

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PubMedDate not supplied

Tumorigenicity, invasiveness and metastatic capability of FR3T3 rat cells before and after transfection with bovine papilloma virus type 1 DNA.

Fischer rat FR3T3 cells were tested for tumorigenicity, invasive and metastatic capabilities before and after transfection, either with the entire bovine papilloma virus type 1 (BPV-1) genome or with a plasmid (pV69) containing a 69 per cent Bam H1-Hind III fragment of the BPV-1 genome as well as bacterial sequences. Cell lines were grouped as parental, pV69-transfectants, BPV-1 transfectants, in vitro derivatives, and in vivo derivatives. The tumorigenic, invasive and metastatic capabilities of these cell lines were examined in vivo through s.c., and i.p. injections of cell suspensions and through s.c. implantations of cellular aggregates into syngeneic rats. Invasiveness was tested in vitro through confrontations with embryonic chick heart fragments in organ culture. All cell lines including parental lines, were found to be invasive in vitro and tumorigenic in vivo; all tumors were invasive. It is, therefore, not possible to draw conclusions about the role of BPV-1 gene sequences in the acquisition of the invasive phenotype. Transfection with BPV-1 genes conveyed the metastatic phenotype upon parental FR3T3 cells, which were themselves found to be non-metastatic. With regards to this, no differences were found between BPV-1 transfectants compared with pV69 transfectants. Untransfected cells became metastatic also through passage in vivo as an s.c. tumor. The expression of the metastatic phenotype was not noticeably correlated with alterations of growth characteristics of the cell lines. We concluded that the implication of BPV-1 gene sequences in conveying the metastatic phenotype upon FR3T3, if any, was indirect, presumably through alterations of the host cell genome. Our experiments illustrate the need for long-term observations with parental cell lines before drawing conclusions about the role of oncogenes in the acquisition of the malignant phenotype.

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PubMedDate not supplied

The use of deep inspiration preceding the Valsalva maneuver and rapid expiration in color Doppler imaging of the lower extremity veins.

Deep inspiration preceding Valsalva maneuver and rapid expiration immediately following it (DIVE) enhance venous blood flow on color Doppler flow imaging (CDI). The effect of DIVE was assessed in 115 consecutive lower extremity examinations. Of these, 95 or 115 (83%) had negative CDI sonograms, and 20 of 115 (17%) had partially (six of 115) or completely (14 of 115) occluding deep vein thrombosis. DIVE enhanced venous blood flow in 68% of the negative cases, resulting in transient venous distention, and/or more complete color filling, and/or greater spectral flow velocities. The 14 cases with completely occluding thrombi showed no response to DIVE. Six cases with partially occluding thrombi showed moderate to mild response to DIVE, with improved color delineation of the residual patent lumen around the thrombus. The authors conclude that DIVE facilitates deep venous CDI, especially when compression cannot be used to augment venous flow.

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PubMedDate not supplied

Chemical composition and microstructure of uroliths and urinary sediment crystals associated with the feeding of high-level cottonseed meal diet to water buffalo calves.

The chemical composition and microstructure of seven uroliths and four urinary sediment samples associated with the feeding of high-level cottonseed meal diet to buffalo calves were examined by chemical qualitative analyses, scanning electron microscopy (SEM), X-ray diffraction, and X-ray energy dispersive spectrometry (EDS). Struvite was a major component of kidney stones and of some bladder stones. The kidney stone sample appeared cracked under low power under SEM, aggregated into tiny balls under high power, and as a blade-like structure under even higher power. The bladder stone samples appeared finely granular or granular with various forms of prismatic crystals. The urinary sediments were prismatic crystals, with granules. The newly found prismatic crystals, which were rich in potassium and similar to struvite in crystal structure, were identified as potassium magnesium phosphate (KMgPO4.6H2O) in some bladder stones and urinary sediments. However, crystals which contained Mg and P only, which had been used for struvite identification, were not found by EDS examination in urinary sediments from fresh urine samples of buffalo calves fed the high-level cottonseed meal diet.

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