Survivin is a recently described inhibitor of apoptosis. Because suppression of apoptosis is important for carcinogenesis and tumor growth, we investigated the expression and function of survivin in human hepatocellular carcinomas (HCCs). We have shown that 4 HCC cell lines and 7 out of 8 human HCC tissues expressed survivin messenger RNA (mRNA), whereas expression of survivin mRNA was not detected in normal liver and nontumor areas of these tissues using the reverse transcription polymerase chain reaction. Survivin was detected primarily in the nucleus by immunofluorescence staining of HCC cells. In addition, 14 of 20 (70%) HCC tissues showed positive nuclear staining for survivin, whereas nontumor tissues showed little detectable staining by immunohistochemistry. Survivin expression strongly correlated with the proliferation index but not significantly with the apoptosis index in HCC tissues. Therefore, we performed cell cycle analysis after survivin transfection and showed that overexpression of survivin resulted in a decrease in the G 0 /G 1 phase and an increase in the S phase in all 4 HCC cell lines. Furthermore, we have found that survivin interacted with cyclin-dependent kinase 4 (Cdk4) and overexpression of survivin released p21 WAF1/Cip1 (p21) from Cdk4. From these results, we conclude that survivin promotes cell proliferation by interacting with Cdk4 and releasing p21 from Cdk4. This may play an important role in carcinogenesis and progression of human HCCs. (HEPA-TOLOGY 2000;31:1080-1085.)Regulation of programmed cell death is important in the preservation of homeostasis and morphogenesis of human tissues. 1,2 Impairment of apoptosis facilitates the accumulation of gene mutations by prolonging the cell cycle span and promoting resistance to immune-based cytotoxicity, 3 finally contributing to carcinogenesis. 4 It has been shown recently that the inhibitors of apoptosis proteins (IAP) are crucial regulators in the molecular mechanism of apoptosis. [5][6][7] Among the IAP members, survivin is unique in that it is undetectable in normal adult tissue, but abundantly expressed in transformed cells and a variety of human cancers. 8 It has also been shown that survivin inhibits apoptosis in cells exposed to diverse apoptotic stimuli 8-11 by associating with microtubules of the mitotic spindle 9 and inhibiting caspase activity. 10 Expression of survivin is highly correlated with prognosis in patients with neuroblastoma, 7,12 gastric cancer, 13 colorectal cancer, 14 and bladder cancers. 15 However, the biological functions of survivin, other than its antiapoptotic effect, are not well understood in human cancers.Therefore, to gain insight into additional roles of survivin in malignant cells, we investigated the expression and function of survivin in hepatocellular carcinoma (HCC) cell lines and human HCC. In this study, we showed that survivin expression correlates with HCC cell proliferation in the majority of human HCC tissues. Survivin overexpression obliterates the G 1 checkpoint by releasing p21 WAF1/Cip...

The hydroxyl radical (OH) plays an important role in plasma chemistry at atmospheric pressure. OH radicals have a higher oxidation potential compared with other oxidative species such as free radical O, atomic oxygen, hydroperoxyl radical (HO 2 ), hydrogen peroxide(H 2 O 2 ) and ozone. In this study, surface discharges on liquids (water and its solutions) were investigated experimentally. A pulsed streamer discharge was generated on the liquid surface using a point-to-plane electrode geometry. The primary generation process of OH radicals is closely related to the streamer propagation, and the subsequent secondary process after the discharge has an influence on the chemical reaction. Taking into account the timescale of these processes, we investigated the behavior of OH radicals using two different diagnostic methods. Time evolution of the ground-state OH radicals above the liquid surface after the discharge was observed by a laser-induced fluorescence (LIF) technique. In order to observe the ground-state OH, an OH [A 2 + (v = 1) ← X 2 (v = 0)] system at 282 nm was used. As the secondary process, a portion of OH radicals diffused from gas phase to the liquid surface and dissolved in the liquid. These dissolved OH radicals were measured by a chemical probe method. Terephthalic acid was used as an OH radical trap and fluorescence of the resulting 2-hydroxyterephthalic acid was measured. This paper directly presents visualization of OH radicals over the liquid surface by means of LIF, and indirectly describes OH radicals dissolved in water by means of a chemical method.

Caspase 3 is an essential death factor for the Fasmediated cell death, and its inactivation in cells is initiated by an interaction with p21 on mitochondria or with IAP family member ILP. Survivin is also a member of IAP family and is speci®cally expressed during embryogenesis and in tumor cells and suppresses cell death signaling. In our current study, we demonstrated that Survivin translocation into the nucleus is dependent on Fas stimulation and cell proliferation. Survivin also interacts with the cell cycle regulator Cdk4, leading to Cdk2/Cyclin E activation and Rb phosphorylation. As a result of Survivin/Cdk4 complex formation, p21 is released from its complex with Cdk4 and interacts with mitochondrial procaspase 3 to suppress Fas-mediated cell death. Here, we propose that Survivin supports procaspase 3/p21 complex formation as a result of interaction with Cdk4 resulting in suppression of cell death signaling.

Survivin is observed uniquely in tumor cells and developmental cells, which undergo either inappropriate or programmed cell growth. In the current study, we investigated the in¯uence of Survivin on cell cycle. Overexpression of Survivin resulted in accelerated S phase shift, resistance to G1 arrest, and activated Cdk2/ Cyclin E complex leading Rb phosphorylation. In addition, nuclear translocation of Survivin followed by an interaction with Cdk4 was detected. Interestingly, Survivin nuclear translocation coincided with S phase shift, and prevention of nuclear transport suppressed Survivin nuclear translocation and S phase shift. Further, we also observed that Survivin competitively interacted with the Cdk4/p16 INK4a complex in a cell free system and in vivo. These results suggest that Survivin initiates the cell cycle entry as a result of nuclear translocation followed by an interaction with Cdk4. Oncogene (2000) 19, 3225 ± 3234.

The role of matrix metalloproteinases (MMP's) and their inhibitor, tissue inhibitor of metalloproteinases-1 (TIMP-1), in human brain tumor invasion was investigated. Gelatinolytic activity was assayed via gelatin zymography, and four MMP's (MMP-1, MMP-2, MMP-3, and MMP-9) and TIMP-1 were immunolocalized in human brain tumors and in normal brain tissues using monoclonal antibodies. The tissue was surgically removed from 44 patients: glioblastoma (five cases), anaplastic astrocytoma (six cases), astrocytoma (four cases), metastatic tumor (six cases), neurinoma (10 cases), meningioma (10 cases), and normal brain tissue (three cases). Glioblastomas, anaplastic astrocytomas, and metastatic tumors showed high gelatinolytic activity and positive immunostaining for MMP's; TIMP-1 was also expressed in these tumors, but some tumor cells were negative for the antibody. Astrocytomas had low gelatinolytic activity and the tumor cells showed no immunoreactivity for MMP's and TIMP-1. Although neurinomas and meningiomas had only moderate proteinase activity and exhibited positive immunoreactivity for MMP-9, intense expression of TIMP-1 was simultaneously observed in these tumor cells. These findings suggest that MMP's play an important role in human brain tumor invasion, probably due to an imbalance between the production of MMP's and TIMP-1 by the tumor cells.

Background and Purpose-The purpose of the present study was to assess the incidence and clinical significance of the intraparenchymal hyperdense areas on the posttherapeutic CT scan just after intra-arterial reperfusion therapy. Methods-Seventy-seven patients with acute middle cerebral artery occlusion were studied prospectively with posttherapeutic CT. Hyperdense areas were classified into three groups: those in the lentiform nucleus, insular cortex and cerebral cortex. We investigated the incidence of hyperdense areas and hemorrhagic transformations and assessed whether location of hyperdense areas may play a role in the incidence of hemorrhagic transformations. We also evaluated correlation between early CT signs and hyperdense areas. Results-Forty-five hyperdense areas were seen in 37 of the 77 patients (48.1%): 19 of the 45 (42.2%) were confirmed to be hematomas themselves, 6 (13.4%) showed later conversion to petechial hemorrhages, and 20 (44.4%) showed rapid disappearance without hemorrhagic transformations. Eleven of the 37 patients (29.7%) had neurological worsening due to massive hematoma (symptomatic hemorrhage), whereas none of the 40 patients without hyperdense areas had symptomatic hemorrhage. The incidence of hemorrhage among hyperdense areas was significantly lower in the insular cortex than in the other 2 regions (PϽ0.01). On the other hand, hyperdense areas in the lentiform nucleus had a significantly higher incidence of neurological worsening (PϽ0.05). There was a significant correlation between early CT signs and hyperdense areas (PϽ0.0001). Conclusions-The presence of hyperdense areas was a significant risk factor for severe hemorrhagic transformations, although only 29.7% of patients with hyperdense areas had symptomatic hemorrhage. On the contrary, the absence of hyperdense areas was a reliable negative predictor for symptomatic hemorrhage.

Mucins are important glycoproteins in the mucociliary transport system of the middle ear and Eustachian tube. Little is known about mucin expression within this system under physiological and pathological conditions. This study demonstrated the expression of MUC5B, MUC5AC, MUC4, and MUC1 in the human Eustachian tube, whereas only MUC5B mucin expression was demonstrated in noninflamed middle ears. MUC5B and MUC4 mucin genes were upregulated 4.2- and 6-fold, respectively, in middle ears with chronic otitis media (COM) or mucoid otitis media (MOM). This upregulation of mucin genes was accompanied by an increase of MUC5B- and MUC4-producing cells in the middle ear mucosa. Electron microscopy of the secretions from COM and MOM showed the presence of chainlike polymeric mucin. These data indicate that the epithelium of the middle ear and Eustachian tube expresses distinct mucin profiles and that MUC5B and MUC4 mucins are highly produced and secreted in the diseased middle ear. These mucins may form thick mucous effusion in the middle ear cavity and compromise the function of the middle ear.

Background and Purpose-The purpose of this study was to evaluate the safety and efficacy of direct percutaneous transluminal angioplasty (PTA) for patients with acute middle cerebral artery (MCA) trunk occlusion. Methods-Over the past 9 years, a total of 70 patients with acute MCA trunk occlusion were treated with intra-arterial reperfusion therapy. In the last 5 years, 34 patients were treated with direct PTA, and subsequent thrombolytic therapy was added if necessary for distal embolization. The other 36 patients, mainly in the first 4 years, were treated with thrombolytic therapy alone and were used as controls. Pretherapeutic neurological status was evaluated with National Institutes of Health Stroke Scale scores. The modified Rankin Scale (mRS) was used to assess clinical outcome at 90 days. Results-There were no significant differences in pretherapeutic National Institutes of Health Stroke Scale score and duration of ischemia between the 2 groups. The rate of partial or complete recanalization in the PTA group was 91.2%, whereas that in the thrombolysis-alone group was 63.9% (PϽ0.01). The incidence of large parenchymal hematoma with neurological deterioration in the PTA group was 2.9%, while that in the thrombolysis-alone group was 19.4% (Pϭ0.03).Although direct PTA did not improve the rate of favorable outcome (mRS score 0 or 1; 41.7% for the thrombolysis-alone group versus 52.9% for the PTA group; Pϭ0.48), outcome in terms of independence (mRS score 0, 1, 2) was significantly better in the PTA group (73.5%) than in the thrombolysis-alone group (50.0%; Pϭ0.04). Conclusions-Although definitive conclusions on the comparative merits of these 2 therapies cannot be drawn because of an open trial, direct PTA may be an effective alternative option to intra-arterial thrombolysis for acute MCA trunk occlusion.