Growth factor involvement and oncogene expression in prostatic tumours

The effects of EGF, TGF alpha and 5 alpha-dihydrotestosterone on the growth of a prostatic epithelial cell line have been evaluated in clonal growth assays. Similar bioassay systems have been used to identify tumour-associated growth promoters derived from a human prostatic carcinoma cell line (PC3). Growth factor activity was associated with proteins of Mr 20-30 kDa. In a separate study, EGF receptor concentration and cellular proto-oncogene expression was assessed in prostatic tumour samples. In prostatic carcinoma samples, strong correlation was observed between EGF receptor concentration and c-myc expression. There were no significant correlations between EGF receptor concentration and tumour grade or androgen receptor content in carcinoma samples. EGF receptor concentration was significantly higher in prostatic carcinoma specimens than in BPH.     

Direct staining and visualization of endothelial monolayers cultured on synthetic polycarbonate filters

Endothelial and epithelial cells cultured on synthetic filter supports have been used to study permeability and transport under various experimental conditions. However, because of the non-transparent nature of these filters, morphological studies using light microscopy are not possible. Presently, investigators circumvent this problem by using cells cultured on glass coverslips, extrapolating morphological data from a system clearly different from that used for functional studies. We describe here a useful technique for direct staining and visualization of cells grown on polycarbonate filter supports, using fluorochrome probes and fluorescence microscopy. We have utilized acridine orange, rhodamine phalloidin, and an anti-vimentin monoclonal antibody to provide information about cell shape, monolayer configuration, and cytoskeletal protein distribution in cultured calf pulmonary artery endothelial cell monolayers. Comparison staining of coverslip and filter preparations revealed a number of clear differences in these parameters. This technique should enable investigators to perform the necessary studies to obtain direct correlations between functional and morphological data.     

Venous air embolism during a craniofacial procedure

The possibility of venous air embolism exists whenever the craniofacial operative field is above the level of the heart. Craniotomy with the high-torque craniotome is hypothesized to have produced venous air embolism in the patient described in this report. The diagnosis of venous air embolism is determined by transesophageal Doppler probe, transesophageal echocardiogram or external echocardiogram, and end-tidal N2 and CO2 determinations. Treatment includes control of the air entry sites, aspiration of air from the right atrium via a catheter placed prior to operation, and discontinuing nitrous oxide. If these measures are unsuccessful, the operative field should be transposed below heart level and the procedure terminated. In the event of significant hemodynamic compromise, closed cardiac massage should be tried; if that fails, open cardiac massage and direct aspiration are necessary. The true incidence of venous air embolism in craniofacial operations may be much higher than previously suspected. We therefore recommend placement of appropriate monitoring equipment to detect intracardiac air in those major craniofacial procedures in which there is a potential for intravascular air ingress.     

Fixation effects on membranous and endochondral onlay bone-graft resorption

Difficulties arise in the prediction of maintenance of graft volume over time when bone grafts are used for facial contour reconstruction. We hypothesize that graft fixation will decrease movement and lead to decreased resorption. Fixed and nonfixed endochondral (rib) and membranous (skull) onlay bone grafts measuring 30 X 10 X 4 mm were grafted to the mandible bilaterally in 10 adult sheep. Fixation was achieved using the lag-screw technique. Volume measurements using caliper technique were made 20 weeks postoperatively. The volume of graft present at 20 weeks was significantly greater for the fixed bone grafts (p less than 0.001): fixed membranous, 85.9 percent; fixed endochondral, 76.2 percent; nonfixed membranous, 55 percent; and nonfixed endochondral, 16.6 percent. The results are explained using biomechanical theories related to the effects of strain. At present, it is suggested by this study that when onlay bone grafts are stabilized, improved results with respect to graft resorption can be expected.     

Correlation of immunomodulatory and therapeutic activities of interferon and interferon inducers in metastatic disease

The mechanism of therapeutic activity of recombinant murine interferon-gamma (rMu IFN-gamma) and the IFN inducer polyinosinic-polycytidylic acid solubilized with poly-L-lysine in carboxy methyl cellulose (pICLC) in treating metastatic disease was investigated by comparing effector cell augmentation with therapeutic activity in mice bearing experimental lung metastases (B16-BL6 melanoma). Effector cell functions in spleen, peripheral blood, and lung (the organ with tumor) were tested after 1 and 3 weeks of rMu IFN-gamma or pICLC administration (intravenous, three times a week). In these studies, natural killer (NK), lymphokine-activated killer (LAK), cytolytic T lymphocytes (CTL) (against specific and nonspecific targets), and macrophage tumoricidal and tumoristatic activities were measured. rM IFN-gamma and pICLC had therapeutic activity and immunomodulatory activity in most assays of immune function examined. Specific CTL activity of pulmonary parenchymal mononuclear cells (PPMC), but not in splenocytes or peripheral blood lymphocytes (PBL), during week 3 and not during week 1, correlated with the therapeutic activity of rMu IFN-gamma and of pICLC. Macrophage tumoricidal activity in PPMC, but not in alveolar macrophages, also correlated with the therapeutic activity of rMu IFN-gamma, but the opposite was true for the therapeutic activity of pICLC. NK activity of PPMC, but not of splenocytes or PBL, during week 1 correlated with the therapeutic activity of pICLC; in contrast, NK activity at any site did not correlate with the therapeutic activity of rMu IFN-gamma. LAK activity at any site did not correlate with the therapeutic activity of either agent.     

Somatic embryogenesis and plant regeneration from zygotic embryo explants in mexican weeping bamboo,Otatea acuminata aztecorum

An efficient protocol has been developed for the in vitro propagation of Mexican Weeping Bamboo through somatic embryogenesis from zygotic embryo explants. Mature seeds and excised embryos were cultured in the light or in the dark on both Murashige and Skoog's and Gamborg's B5 basal media with various supplements. Optimal somatic embryogenesis and plant regeneration were obtained by culture in the dark on Murashige and Skoog's basal medium supplemented with 3 mg/1 2,4-dichlorophenoxyacetic acid, 0.5 mg/1 6-benzylaminopurine and 2.0% sucrose. More than 95% of the germinating somatic embryos developed shoots and roots, and were transferred to soil with 85% success.