88 Severe tricuspid regurgitation due to papillary muscle rupture: A rare complication of anterior myocardial infarction and ventricular septal perforation

INTRODUCTION

Papillary muscle rupture (PMR) of the mitral valve is a fatal complication of acute myocardial infarction (MI). As a complication of anterior MI, PMR of the tricuspid valve is extremely rare. We experienced a case of acute anterior MI complicated with tricuspid PMR and ventricular septal perforation (VSP).

REPORT

An 85-year-old woman was admitted with general fatigue and appetite loss. Her consciousness was alert, but she was pale, and had cold extremities. Her blood pressure was 74/62 mmHg, and pulse was 99/min. There was no leg edema. Pan systolic regurgitant murmur (Levine III/VI) was audible at the lower left sternal border. Her oxygen saturation was 86% under room air. Electrocardiogram revealed ST segment elevation and QS pattern in V1 to V3. Transthoracic echocardiography revealed dyskinesis of the apical anterior septum, VSP with bidirectional shunt, and severe pulmonary hypertension. Left ventricular ejection fraction was preserved (58%). The anterior tricuspid leaflet was flail due to PMR, resulting in severe tricuspid regurgitation and right ventricular dilatation. Coronary angiography revealed a single vessel disease of the left anterior descending artery (LAD). We recommended surgical treatment, and transferred her to another hospital.

DISCUSSION

Common causes of tricuspid PMR are infective endocarditis and chest trauma. Right ventricular infarction, usually caused by right coronary artery (RCA) occlusion, may cause tricuspid PMR. In our case, however, tricuspid PMR was complicated with anterior MI. The tricuspid anterior, posterior, and septal leaflets are attached to anterolateral RV wall, inferior septum, and infundibular septum, respectively, via papillary muscles. Right ventricular branches and septal branches of the RCA usually supply these papillary muscles. Anterior leaflet PMR in this case was possibly due to anomalous blood supply of anterolateral RV wall by the right ventricular branches of the LAD. Right ventricular overload due to large VSP shunt elevated RV diastolic pressure and right atrial pressure, and might worsen ischemia of the RV wall.

Abstract 88 Figure. severe TR & shunt flow through VSP

Picosecond resonance Raman spectroscopic evidence for excited-state spin conversion in carbonmonoxy-hemoglobin photolysis

The structure of the carbonmonoxy-hemoglobin (COHb) photoproduct has been studied on the picosecond time scale with resonance Raman spectroscopy, by tightly focusing the 30-ps pulses of a synchronously pumped mode-locked cavitydumped dye laser on a jet stream of COHb solution. The spectrum of the photoproduct is similar to that of deoxy Hb, but the frequencies 1603 cm(-1) (depolarized), 1552 cm(-1) (anomalously polarized), and 1542 cm(-1) (depolarized) are 2-4 cm(-1) lower than those of deoxy Hb. Similar low frequencies are observed for a species believed to be the bis-tetrahydrofuran adduct of Fe(II) octaethylporphyrin, containing in-plane high-spin Fe(II). These results indicate that in the COHb photoproduct the Fe(II) is already high-spin but is closer to the heme plane than in deoxy Hb. Photodissociation from a quintet ligand-field excited state of COHb is suggested. The frequency shifts relative to deoxy Hb persist when the laser pulses are lengthened to 20 ns. The apparently slow relaxation to the fully out-of-plane heme conformation of deoxy Hb is suggested to be associated with change of the globin tertiary structure.

Hypercalcemic complication in patients with oral squamous cell carcinoma

Hypercalcemia is one of the metabolic complications associated with cancer. To assess the frequency of hypercalcemia in patients with squamous cell carcinoma (SCC), 242 patients who were evaluated as having SCC in the oral cavity between July 1995 and June 2001 were investigated. All patients were periodically monitored for their serum level of calcium (Ca). Hypercalcemia was defined as a serum Ca concentration higher than 11 mg/dl. By this definition, hypercalcemia was detected in 12 of the 242 patients (5.0%). All 12 patients were at an advanced stage of oral SCC. In these 12 patients, the serum level of parathyroid hormone-related protein (PTH-rP) was also significantly elevated. Therefore, we diagnosed these diseases as humoral hypercalcemia of malignancy (HHM). Moreover, we studied the efficacy of anti-hypercalcemic therapy on the quality of life (QOL). The European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 was used for estimation of QOL. The patients with HHM who were administrated drugs such as bisphosphonate and calcitonin showed a reduction in their Ca and PTH-rP levels, and the six of ten EORTC QLQ-C30 subscales (emotional functioning, cognitive functioning, fatigue, dyspnoea, nausea/vomiting and appetite loss) were also improved after the anti-hypercalcemic therapy. However, these suppressive effects were temporary. The median survival time after the diagnosis of HHM was only 54.9+/-18.3 days (range 27-86 days). Therefore, HHM in SCC appears to be an ominous prognostic sign. Although anti-hypercalcemic therapy has a palliative role, the patients may be in less discomfort during the terminal stage of their illness.

Role of interleukin-8 secreted from human oral squamous cell carcinoma cell lines

Interleukin-8 (IL-8) is an important cytokine involved in tumor growth and angiogenesis in a variety of malignancies. Furthermore, matrix metalloptoteinases (MMPs) also play important roles in the invasion and metastasis of carcinomas including oral squamous cell carcinoma (OSCC). We studied whether IL-8 and MMPs participate in tumorigenesis and metastasis of OSCC. First, we investigated the gene and protein expressions of IL-8 and IL-8 receptor (IL-8R), and the effect of IL-8 on proliferation, migration and invasion of OSCC. Second, we thus also investigated the effect of IL-8 on MMP release in OSCC cells. OSCC cell lines NA and HSC-4 constitutively expressed IL-8 mRNA and secreted its protein in vitro. The production of IL-8 was significantly enhanced by the addition of tumor necrosis factor (TNF)-alpha and IL-beta, but not interferon (IFN)-gamma, granulocyte-macrophage colony-stimulating factor (GM-CSF) or IL-2. Flow cytometric analysis revealed the constitutive expression of both receptors of IL-8, IL-8RA and IL-8RB, in OSCC cell lines. The expression of IL-8 receptors in HSC-4 cells was stronger than that in NA cells. The intensity of IL-8RA expression was stronger than that of IL-8RB expression in each cell line. The expression of IL-8 receptors was not altered by the addition of cytokines such as TNF-alpha and IL-1beta. The conditioned medium containing IL-8 from OSCC cell lines induced migration and invasion of OSCC cells, but did not change cell proliferation. The differences in migrational and invasive ability between NA cells and HSC-4 cells were correlated with the expression intensity of IL-8 receptors in each cell line. Neutralizing antibodies to IL-8, IL-8RA and IL-8RB partially inhibited the chemotactic activity induced by conditioned medium. The expression of MMP-2, -7 and -9 was detected in culture supernatants from these OSCC cell lines. The expressions of MMP-7 protein and mRNA were enhanced by the addition of rIL-8, but that of other MMPs was not observed in a similar manner. These results suggest that IL-8 secreted from OSCC may contribute to the invasion of OSCC through the regulation of MMP-7 expression.

Inhibitor of cyclooxygenase-2 induces cell-cycle arrest in the epithelial cancer cell line via up-regulation of cyclin dependent kinase inhibitor p21

Cyclooxygenase-2 is the rate-limiting enzyme in synthesis of prostaglandins and other eicosanoids. Prior reports have shown that inhibition of cyclooxygenase-2 activity, either by selective inhibitors or by antisense oligonucleotide, results in suppression of growth of squamous cell carcinoma cell lines which express high cyclooxygenase-2 levels, such as NA, a cell line established from a squamous cell carcinoma of the tongue. To investigate the mechanisms by which cyclooxygenase-2 inhibitors suppressed growth of these cells, the effects of NS-398, the selective cyclooxygenase-2 inhibitor, on cell-cycle distribution were examined. NS-398 induced G0/G1 cell-cycle arrest in NA cells which expressed cyclooxygenase-2. G0/G1 arrest induced by NS-398 was accompanied by up-regulation of cyclin-dependent kinase inhibitor p21, but not by up-regulation of the other cyclin-dependent kinase inhibitors. Transfection with p21 antisense oligonucleotide inhibited cell-cycle arrest induced by NS-398. Accumulation in G0/G1 was also observed in NA cells transfected with cyclooxygenase-2 antisense oligonucleotide. On the other hand, NS-398-treated NA cells showed a loss of plasma membrane asymmetry, a marker of early events in apoptosis. However, NS-398 did not induce other morphological and biochemical changes related to apoptotic cell death. These results suggest that cyclooxygenase-2 inhibitor induces G0/G1 cell-cycle arrest in NA cells by up-regulation of p21. Our results also suggest that NS-398 is not sufficient to complete the whole process of apoptosis in NA cells, although it induces an early event in apoptosis.

Proliferation and differentiation of bone marrow cells on titanium plates treated with a wire-type electrical discharge machine

For successful dental implants, it is necessary to obtain satisfactory osteointegration at the site of both the cortical and trabecular bones in the jaw. Bone marrow stromal cells differentiate into osteoblast-lineage cells and have an important role in bone remodeling. In this experiment, the responsiveness of bone marrow cells to a titanium plate with a rough surface was compared with that of a titanium plate with a smooth surface. The rough surface was created by treating with a wire-type electrical discharge machine, and the smooth plate was produced by polishing with 1.500-grade emery paper. The results indicated that, though bone marrow cells proliferated on both plates, the proliferation pattern and cell growing time on the plates were different. While the cells on the smooth plate proliferated along the grooves produced by polishing, the cells on the rough plate proliferated randomly and more rapidly. As bone marrow cells consisted of heterogeneous cell populations involving hematopoietic cells, we collected bone marrow mesenchymal stromal cells that proliferated on plastic dishes and studied the proliferation and differentiation of these cells. Stromal cells on the rough plate more actively proliferated than those on the smooth plate. In long-term culture, the cells on the rough plate showed higher alkaline phosphatase activity and produced cell nodules. The cells on the smooth plate were stripped off the plate without nodule formation. These results indicated that bone marrow stromal cells on the rough plate could more rapidly proliferate and differentiate into osteoblast-lineage cells compared with those on the smooth plate.

Hypercalcemia in patients with oral squamous cell carcinoma

Humoral hypercalcemia of malignancy (HHM) is one of the most common metabolic complications associated with cancer. A retrospective study of hypercalcemia in patients with squamous cell carcinoma of the oral cavity was undertaken. All patients were periodically monitored for their serum level of calcium (Ca). Hypercalcemia was defined as a serum Ca concentration higher than 11 mg/dl of the correction for serum albumin concentration. The serum levels of parathyroid hormone related protein (PTH-rP) were also measured by radioimmunoassay. Hypercalcemia was detected in ten of 246 patients (4.1%). All ten patients were at an advanced stage of oral squamous cell carcinoma (SCC, Stage IVA, IVB or IVC). In these ten patients, the serum level of PTH-rP was significantly elevated, 238 +/- 91 pmol/l (range, 108-380 pmol/L). The patients with HHM who underwent antihypercalcemic therapy showed reduced Ca levels relating to PTH-rP levels; however, the Ca concentration was temporarily improved after anti-hypercalcemic treatment. The median survival time after diagnosis of HHM was only 55.8 +/- 19.9 days (range, 27-86 days). HHM in oral cancer is likely attributable to PTH-rP, and its occurrence appears to be an ominous prognostic sign.

Inhibitors of cyclooxygenase-2 (COX-2) suppressed the proliferation and differentiation of human leukaemia cell lines

Prostaglandins (PG) are known to play important roles in the proliferation and differentiation of leukaemia cells. The effect of the inhibitors of cyclooxygenase-2 (COX-2), a rate-limiting enzyme for the synthesis of PG, on the proliferation and differentiation of leukaemia cell lines was investigated. COX-2 inhibitors, NS-398 and nabumetone, suppressed the proliferation of U-937 and ML-1 cells by inducing a G0/G1 cell-cycle arrest. Cell-cycle arrest induced by these COX-2 inhibitors was not associated with an upregulation of the cyclin-dependent kinase inhibitors. COX-2 inhibitors also inhibited the differentiation of these cells induced by interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha) and retinoic acid (RA). Treatment with NS-398 did not suppress the levels of PGs produced by these cells. Although COX-2 antisense oligonucleotide showed a similar inhibitory effect on these cells, its inhibitory effect was smaller than that of NS-398. These results suggest that COX-2 inhibitors may suppress the proliferation and differentiation of leukaemia cells both via COX-2-dependent and -independent pathways.

Specific inhibition of cyclooxygenase-2 results in inhibition of proliferation of oral cancer cell lines via suppression of prostaglandin E2 production

Prostaglandins (PGs) are known to play important roles in the proliferation of various types of cancer cells. PGs are produced by the action of cyclooxygenase (COX) enzymes, and two forms of COX, COX-1 and COX-2, have been described. Previous studies have demonstrated that overexpression of COX-2 is associated with colon carcinogenesis, tumor invasion and metastatic potential of colon cancer. In this study, the role of COX-2 on proliferation of squamous cell carcinoma cell lines was investigated. NS-398, a selective COX-2 inhibitor, inhibited proliferation of NA cells, a squamous cell caricinoma cell line that constitutively expresses COX-2 mRNA. NS-398 suppressed the spontaneous production of PGE2 by NA cells, and the antiproliferative effect of NS-398 was abolished by addition of PGE2. Similar results were obtained from experiments using COX-2 antisense oligonucleotide. These results suggest that specific inhibition of COX-2 inhibits proliferation of cancer cells expressing COX-2 mRNA via suppression of PGE2 production.

Involvement of caspases in 5-FU induced apoptosis in an oral cancer cell line

Although many anticancer drugs have been reported to induce apoptosis in cancer cells, the underlying mechanism remains unclear (1-3). Recent studies have revealed that the caspase family of cysteine proteases have been shown to play an important role in the regulation of several apoptotic processes. Thus, the present study investigated whether apoptosis induced by anticancer drugs is mediated by the activation of caspase cascade. NA cells, a squamous cell carcinoma cell line, were exposed to cisplatin (CDDP) or 5-fluorouracil (5-FU) with or without inhibitors of caspase 1, 3 and 8. Analysis of DNA fragmentation revealed that caspase inhibitors consistently inhibited DNA fragmentation induced by 5-FU. During the early stages of apoptosis, phosphatidylserine (PS) is translocated from the inner side of the plasma membrane to the cell surface. This PS externalization was markedly inhibited by treatment with caspase-8 inhibitor. These findings suggested that 5-FU induced apoptosis was mediated by the activation of a caspase cascade involving caspase 1, 3 and 8.

Effects of cytokines on the production of nitric oxide in a chondrogenic cell line established from human osteogenic sarcoma

OBJECTIVES

The purpose of this study was to examine the effects of various cytokines and/or lipopolysaccharide (LPS) on nitric oxide (NO) production from USAC, a newly established clonal cell line derived from human osteogenic sarcoma that expressed chondrocytic phenotypes.

MATERIALS AND METHODS

No production was measured by Griess method. Inducible nitric oxide synthase (iNOS) mRNA was detected by PCR analysis. Western blotting analysis and immunocytochemistry was used to detect iNOS protein.

RESULTS

Although USAC cells treated without any stimulants produced only small amounts of NO, exposure to cytokines and/or LPS induced iNOS in USAC cells and produced high levels of NO. The stimulatory effects of cytokines and/or LPS on NO production required TNF-alpha. TNF-alpha alone neither induced iNOS in USAC cells nor caused production of NO, but addition of TNF-alpha to USAC cells pretreated with LPS and IFN-gamma enhanced the expression of iNOS mRNA, induced iNOS protein and produced NO. Dexamethasone inhibited the stimulatory effect of TNF-alpha.

CONCLUSIONS

The responsiveness of USAC cells to cytokines and/or LPS and steroid hormone on NO production was quite different from that reported for rabbit and human articular cartilaginous cells. The differences in responsiveness between articular cartilaginous chondrocytes and USAC cells might have been because USAC cells were established from a malignant tumor.

Establishment of a cell line with phenotypes of chondrocyte from a human osteogenic sarcoma of the mandible

We have succeeded in transplanting a human osteogenic sarcoma of the mandible into athymic mice. The transplanted tumor showed marked chondrogenesis and mineralization. Recently, a cell line (USAC) with phenotypes of chondrocyte has been established from the transplanted tumor. USAC cells were stellate or spindle-shaped in sparse culture, but polygonal or spherical at sub-confluency to confluency. In long-term culture, the cells were condensed and calcified nodules were formed. Production of types I, II and X collagen were detected by immunohistochemical staining and Western blot analysis. Type I collagen was strongly expressed in the stellate or spindle-shaped cells. Although type II collagen was usually present in all cells during culture, it was strongly stained in polygonal cells at confluency. Type X collagen was seen in large polygonal cells around calcified nodules. Marked [35S]-sulfate uptake and metachromasia were seen at the confluent stage and in the nodule. The cells around the nodules were positive for alkaline phosphatase, and the center of the nodules was stained with alizarin red. The potentiality of cartilage formation was confirmed by in vivo experiments using a diffusion chamber in athymic mice. These observations indicate that USAC cells maintain characteristics of chondrocyte progenitor cells and thus may serve as a useful model to study the sequential events of chondrogenesis and the process of morbid endochondral calcification. This experiment also demonstrated that transplantation of tumor tissue into athymic mice is a convenient strategy for establishment of a cell line.

Changes in susceptibility to Fas-mediated apoptosis during differentiation of HL-60 cells

The Fas-mediated pathway has been implicated as an important cellular pathway mediating apoptosis in diverse cell types. We conducted studies to examine the susceptibility to Fas-mediated apoptosis of HL-60 cells treated with differentiation-inducing factors such as dimethyl sulfoxide (DMSO), retinoic acid (RA), and 1alpha, 25 dihydroxyvitamin D3 (VD3). Although the expression of Fas antigen (Ag) and its mRNA showed a marked increase in HL-60 cells with cell differentiation, that of Bcl-2 protein and its mRNA revealed the reverse. The expression of caspase proteins such as caspases-3 and -8 was also enhanced during cell differentiation. DNA fragmentation, annexin V binding, and caspase activities increased in differentiated HL-60 cells with the addition of anti-Fas Ag antibody. These findings were more clearly demonstrated in DMSO- or RA-induced neutrophil-like cells than in VD3-induced monocyte-like cells. Therefore, susceptibility to Fas-mediated apoptosis showed an increase with differentiation of HL-60 cells, especially in the neutrophil lineage. These results suggest that the difference of susceptibility to Fas-mediated apoptosis among cell populations depends on the expression of Fas Ag, Bcl-2, and caspases. Cell maturation and susceptibility to Fas-mediated apoptosis may be linked in hematopoietic cells.

Recombinant human bone morphogenetic protein-2 stimulates osteoblastic differentiation in cells isolated from human periodontal ligament

Periodontal ligament cells may play an important role in the successful regeneration of the periodontium. We investigated the effects of recombinant human bone morphogenetic protein-2 (rhBMP-2), one of the most potent growth factors that stimulates osteoblast differentiation and bone formation, on cell growth and osteoblastic differentiation in human periodontal ligament cells (HPLC) isolated from four adult patients. rhBMP-2 induced no significant changes in cell growth in any of the HPLCs. rhBMP-2 at concentrations over 50 ng/mL significantly stimulated alkaline phosphatase (ALPase) activity and parathyroid hormone (PTH)-dependent 3', 5'-cyclic adenosine monophosphate accumulation, which are early markers of osteoblast differentiation, in the HPLCs. rhBMP-2 (500 ng/mL) also slightly enhanced the level of PTH/PTH-related peptide receptor mRNA expression in these cells. While interleukin-1 beta enhanced ALPase activity stimulated with rhBMP-2, tumor necrosis factor-alpha inhibited the rhBMP-2-stimulated activity. Interleukin-6 induced no significant changes in ALPase activity stimulated with rhBMP-2. Although HPLCs, whether treated with rhBMP-2 or not, could not produce measurable amounts of osteocalcin, which is a marker of more mature osteoblasts, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] induced osteocalcin mRNA expression and protein synthesis in these cells. rhBMP-2 inhibited 1,25(OH)2D3-induced osteocalcin synthesis in HPLCs at both the mRNA and protein levels. These results suggest that rhBMP-2 provides an anabolic effect on periodontal regeneration by stimulation of osteoblastic differentiation in human periodontal ligament cells, and that this stimulatory effect is differentially modulated by inflammatory cytokines during the course of periodontal regeneration.

Elevated production of salivary nitric oxide in oral mucosal diseases

Nitric oxide (NO) is known to play an important role in biological systems. In this study, we measured levels of NO in the saliva of 39 patients with oral mucosal diseases: 21 had oral lichen planus (OLP) and 18 had recurrent aphthous ulceration (RAU). NO was assayed using the Griess reagent, which measures nitrite (NO2), the byproduct of NO. NO2 was detected in all tested samples, and levels in the saliva of patients were significantly increased relative to those of healthy subjects. We also examined the effect of NO on fibroblasts, keratinocytes and NA cells (an epithelial cancer cell line) in vitro. S-nitroso-N-acetyl-DL-penicillamine (SNAP) and 3-morpholinosydnonimine (SIN-1) were used as NO donating reagents. The results revealed that cell viability was significantly reduced by NO derived from SNAP and SIN-1 in a dose-dependent manner. Although the role of salivary NO in normal physiology is as yet unknown, these findings suggest that excessive salivary NO plays a potential role in modifying oral mucosal diseases as a physiopathological regulator.

Altered growth response of oral mucosal keratinocytes in p53-deficient mice

P53 has important regulatory functions in cell growth, differentiation and apoptosis. Here we analyzed the effects of p53 on the growth response of oral mucosal keratinocytes (OMKCs) using p53-deficient (p53-/-) mice. No morphological difference was found between p53-/- and wild-type (p53+/+) oral mucosa. In a long-term culture, p53-/- OMKCs continued to proliferate past the point at which p53+/+ became senescent. The percentage of p53-/- OMKCs in the G0/G1 phase was lower than that of p53+/+ OMKCs. Proliferation of cultured OMKCs induced by epidermal growth factor (EGF) and interleukin-(IL)-1alpha was more strongly enhanced in p53-/- than in p53+/+ mice. Such an enhanced response was not due to increased mRNA expression of growth factor receptors. These data suggest that p53 acts as a modulator of G1 arrest in OMKCs and is also involved in the regulation of responses to EGF and IL-1alpha without affecting the expression of their receptors.

Redo cardiac surgery for atrial septal defect in a patient with idiopathic thrombocytopenic purpura. Preoperative management with high-dose intravenous gamma-globulin

A 58-year-old woman with idiopathic thrombocytopenic purpura required redo cardiac surgery of atrial septal defect closure, mitral annuloplasty, and tricuspid annuloplasty. Preoperative high-dose intravenous gamma-globulin and platelet transfusion after termination of cardiopulmonary bypass allowed successful redo cardiac surgery. Management of a patient with idiopathic thrombocytopenic purpura undergoing open heart surgery are discussed.

Synergistic induction of ICAM-1 expression by cisplatin and 5-fluorouracil in a cancer cell line via a NF-kappaB independent pathway

Cisplatin (CDDP) and 5-fluorouracil (5-FU) are common anti-tumour agents, and the anti-tumour effect of CDDP and 5-FU are synergistically enhanced by combined treatment. To clarify the mechanisms of this synergism, we examined the effect of CDDP and 5-FU on the expression of cell adhesion molecules involved in recognition of cancer cells by T lymphocytes. When NA cells, a squamous cell carcinoma cell line, were exposed to CDDP and 5-FU for 18 h, the expression of intercellular adhesion molecule-1 (ICAM-1) was synergistically induced, whereas CDDP or 5-FU alone did not induce the expression of ICAM-1, as determined by flow cytometry. Expression of ICAM-2 and ICAM-3, which are recognized by the same counter receptor on T-cells, were not up-regulated by CDDP and 5-FU. RT-PCR analysis showed that the induction of ICAM-1 on NA cells might be due to transcriptional induction of ICAM-1 mRNA. Treatment with genistein, a protein tyrosine kinase (PTK) inhibitor, inhibited the induction of ICAM-1 on NA cells by CDDP and 5-FU, whereas staurosporin, a protein kinase C inhibitor, did not. Although CDDP and 5-FU induced binding at the nuclear factor kappa B (NF-kappaB) site in the ICAM-1 promoter, pretreatment with genistein did not prevent CDDP and 5-FU-induced binding at the NF-kappaB site. Moreover, a NF-kappaB nuclear translocation inhibitor did not inhibit the induction of ICAM-1 expression by treatment with CDDP and 5-FU. The synergistic effect of CDDP and 5-FU was not specific to NA cells, since ICAM-1 was synergistically induced by CDDP and 5-FU on HSC-4 cells, a squamous cell carcinoma cell line. These findings indicate that treatment with CDDP and 5-FU induces ICAM-1 expression by a NF-kappaB independent regulatory mechanism involving PTK.

Nitric oxide up-regulates the expression of intercellular adhesion molecule-1 on cancer cells

Nitric oxide (NO) is an unstable free radical that functions as a cytotoxic agent secreted by macrophages to kill cancer cells. Here we report the effect of NO on the expression of intercellular adhesion molecule-1 (ICAM-1) on cancer cells. NO donors such as SNP, SNAP and SIN-1 up-regulated the expression of ICAM-1 on NA cells, a squamous cell carcinoma cell line. Northern blot analysis showed that the induction of ICAM-1 might be due to transcriptional induction of ICAM-1 mRNA. Up-regulation of ICAM-1 mRNA by NO donors was inhibited by carboxy-PTIO, a NO scavenger. Although NF-kappaB activity was induced by NO donors, AP-1 was not induced by them. Staurosporin, a protein kinase C (PKC) inhibitor, inhibited the induction of ICAM-1 on NA cells by NO, whereas genistein, a protein tyrosine kinase inhibitor, did not. These findings indicate that NO up-regulates ICAM-1 expression on cancer cells by a regulatory mechanism involving PKC and suggest that NF-kappaB, but not AP-1, might be involved in induction of ICAM-1 by NO in cancer cells.

Recombinant human bone morphogenetic protein-2 stimulates osteoblast differentiation and suppresses matrix metalloproteinase-1 production in human bone cells isolated from mandibulae

Bone morphogenetic protein (BMP), a member of the transforming growth factor superfamily, is one of the most potent growth factors that stimulate osteoblast differentiation and bone formation. We investigated the effects of recombinant human BMP-2 (rhBMP-2) on osteoblast differentiation and matrix metalloproteinase-1 (MMP-1) production in human bone cells (HBC) isolated from mandibulae of 3 adult patients. rhBMP-2 at concentrations over 50 ng/ml significantly stimulated alkaline phosphatase activity and parathyroid hormone (PTH)-dependent 3', 5'-cyclic adenosine monophosphate accumulation, which are early markers of osteoblast differentiation, in HBCs. rhBMP-2 (500 ng/ml) also enhanced the level of PTH/PTH related-peptide receptor mRNA expression in HBCs. Although neither HBCs untreated nor treated with rhBMP-2 produced measurable amounts of osteocalcin, which is a marker of more mature osteoblasts, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] induced ostocalcin mRNA expression and its protein synthesis in these cells. rhBMP-2 inhibited 1,25(OH)2D3-induced osteocalcin synthesis in HBCs at both the mRNA and protein level. rhBMP-2 also significantly suppressed MMP-1 production and MMP-1 mRNA expression at concentrations over 500 ng/ml. These results suggest that rhBMP-2 exerts anabolic effects on human osteoblastic cells derived from mandibulae by stimulation of osteoblast differentiation and down-regulation of MMP-1 synthesis.

Changes in bite force and occlusal contacts in patients treated for mandibular prognathism by orthognathic surgery

PURPOSE

The purpose of this study was to evaluate changes in bite force and occlusal contacts before and after orthognathic surgery in patients with mandibular prognathism and to compare the findings with those in controls with normal occlusion.

PATIENTS AND METHODS

Bite force and occlusal contacts were analyzed in 23 (7 male and 16 female) patients with mandibular prognathism before and after sagittal split ramus osteotomy, and in 20 (10 male and 10 female) controls with normal occlusion. The bite force and occlusal contacts were simultaneously measured by a computerized occlusal analysis system, the T-Scan system, immediately before surgery, and at 6 weeks, 3 months, 6 months, and 1 year postoperatively.

RESULTS

Both the bite force and occlusal contacts in the patients were significantly less than those in the controls before surgery. Although both the bite force and occlusal contacts in the patients were improved by the orthognathic surgery, neither approached the level in the controls within 1 year. Bite force was correlated with the number of occlusal contacts in both patient and control groups.

CONCLUSION

The postoperative masticatory function does not reach control levels even 1 year after the orthognathic surgery for mandibular prognathism. Therefore, further adjustment of the occlusion should be considered before the end of treatment.

[A case of surgical treatment for giant pseudoaneurysm of the left ventricle after myocardial infarction]

A 70-year-old male was admitted for acute postero-inferior myocardial infarction. In cardiac catheterization one month later, there was narrowing of the distal left circumflex artery and the aneurysm of the postero-inferior wall of the left ventricle. The echocardiogram strongly suggested the pseudoaneurysm of the left ventricle. At operation, a large postero-inferior aneurysm was densely adherent to the pericardium. After cardiopulmonary bypass was established, the aorta was cross-clamped and cold cardioplegia was infused, the aneurysm was opened without excision of it. There was a 4 cm by 5 cm defect in the postero-inferior wall of the left ventricle, which communicated with the cavity of the aneurysm. The defect was closed with a patch. Pseudoaneurysm of the left ventricle was diagnosed by histological examination. The postoperative course was uneventful and he discharged on 29th day after surgery.

Burkitt's lymphoma involving the mandible: report of a case and review of Japanese cases

A Japanese case of Burkitt's lymphoma is presented. The intraoral and panoramic images showed alveolar bone destruction with an infiltrative border, displacement of lower molars, root resorption, and loss of lamina dura and the follicular cortex of a developing tooth, similar to descriptions in previous reports. Computed tomography revealed that a primary lesion occupied the mandible and extended to the muscles of facial expression and to the sublingual and submandibular spaces. Another soft tissue mass was evident in the contralateral parapharyngeal space. Results of a survey of the Japanese literature are also presented; they indicate differences in the clinical features between Japanese cases and African and American cases of Burkitt's lymphoma.

Left atrial ball thrombus in a patient without mitral valve disease

We experienced a large left atrial ball thrombus in a patient without mitral valve disease. By transthoracic echocardiography the mass was appeared to be free-floating and swinging randomly in the left atrium. An urgent operation was performed successfully. Operative findings revealed the mass to be a large ball thrombus loosely attached to atrial wall. We suggest that surgical removal is indicated as soon as possible, because of a very high risk of embolism or circulatory collapse.

Cardiac extension of intravenous leiomyomatosis with successful resection

A case of intravenous leiomyomatosis spreading to the right ventricle is described. A 28-year-old woman had been previously diagnosed as having a smooth muscle tumor of borderline malignancy after hysterectomy for a large uterine tumor, because of its unusual invasive character. Based on the above diagnosis, the patient had been managed clinically as having a uterine sarcoma. One year after her hysterectomy, a local recurrence in the pelvic cavity was detected. Two years later, the tumor appeared as a cardiac tumor causing syncope. The tumor was totally resected in two surgical stages, and the correct diagnosis of an intravenous leiomyomatosis was made. The diagnostic and operative considerations are reviewed and the preferred surgical procedure is discussed.

Clinical trial of recombinant granulocyte colony-stimulating factor for chemotherapy-induced neutropenia patients with oral cancer

PURPOSE

This study was undertaken to evaluate the efficacy and toxicity of recombinant human granulocyte colony-stimulating factor (rhG-CSF) in reducing neutropenia in patients with oral cancer undergoing intensive chemotherapy.

MATERIALS AND METHODS

Patients with chemotherapy-induced neutropenia (< 1 x 10(9)/L) were divided into two groups: control group (n = 13) and rhG-CSF administration group (n = 16). rhG-CSF was administered subcutaneously at a dose of 75 micrograms/day on consecutive days. Peripheral blood cell counts and oral complications were investigated in each group.

RESULTS

The duration of neutropenia and absolute neutrophil nadir counts were significantly improved by administration of G-CSF. No consistent effect on thrombocytopenia was noted. Administration of rhG-CSF also reduced the duration and degree of oral complications associated with chemotherapy-induced neutropenia. Intolerable side effects associated with administration of rhG-CSF were not observed.

CONCLUSION

It was concluded that rhG-CSF is effective in shortening the duration of neutropenia after chemotherapy at a dose of 75 micrograms/day.

Positional changes in the mandibular condyle and amount of mouth opening after sagittal split ramus osteotomy with rigid or nonrigid osteosynthesis

PURPOSE

The purpose of this study was to investigate postoperative positional changes in the mandibular condyle and mouth opening in patients undergoing sagittal split ramus osteotomy with either rigid or nonrigid osteosynthesis.

PATIENTS AND METHODS

The forty-six patients with mandibular prognathism underwent sagittal split ramus osteotomy for mandibular set back followed by fixation with one of four methods: circumferential wire (n = 11), lag screw technique (n = 10), positional screw technique (n = 10), or miniplates (n = 15). The changes in the condylar position were assessed by measuring the angle of the condylar long axis (the condylar angle) on submentovertex radiographs. Mouth opening was evaluated by measuring the interincisal distance immediately after the release of maxillomandibular fixation and by monitoring the duration of trismus.

RESULTS

Regardless of the procedure used the condylar angle increased in most patients after surgery (80 of 92 condyles). Although the amount of increase tended to be higher with rigid osteosynthesis than with nonrigid osteosynthesis, no significant differences were observed among the groups. Mouth opening was not significantly influenced by the type of osteosynthesis, and no patient complained of limitation 1 year after surgery.

CONCLUSIONS

Although inward rotation of the condyle frequently occurs after osteosynthesis regardless of the procedure used, the changes in condylar position are within the range of adaptability of the patient.

Osseointegration of dental implants in rabbit bone with low mineral density

PURPOSE

The purposes of this study were to establish an experimental animal model with bone of low mineral density, and to then investigate the reaction of the bone-implant interface in these experimental animals.

MATERIALS AND METHODS

To prepare the experimental model, rabbits were ovariectomized and fed a 0.15% low-calcium diet. The bone mineral density (BMD) of the tibia was periodically measured by dual-energy X-ray absorptiometry. Approximately 1 month after the introduction of the low-calcium diet, when BMD had decreased to about 12% less than that of control rabbits, a titanium implant (TI) was inserted into the tibia of each rabbit. At 2, 4, 8, and 12 weeks after the insertion of the TI, the rabbits were killed, and the reaction of the bone tissue surrounding the TI was examined both histologically and radiographically.

RESULTS

The combined ovariectomy and low-calcium diet produced rabbits having bone with low mineral density, and the histologic features of the tibia in these rabbits were consistent with those in human osteoporotic bone. In control rabbits, new bone formation surrounding the TI was evident 2 weeks after its insertion, and the TI surface was almost completely covered with new bone after 8 weeks. In contrast, new bone formation in the experimental rabbits was delayed, but considerable direct bone contact with the TI was observed after 12 weeks.

CONCLUSION

These results suggest that osteoporotic bone may affect the healing period of bone tissue after the insertion of dental implants, but that osseointegration of dental implants may be obtained even in osteoporotic bone.

Cytotoxic effect of sodium nitroprusside on cancer cells: involvement of apoptosis and suppression of c-myc and c-myb proto-oncogene expression

Nitric oxide (NO) is an unstable free radical gas known as an effector molecule of macrophage cytotoxicity against cancer cells. Although several mechanisms of NO-mediated cytotoxicity have been proposed, this phenomenon remains to be characterized in detail. To explore the mechanisms by which NO kills cancer cells, we made use of sodium nitroprusside (SNP), which releases NO in the culture medium. SNP showed a dose-dependent cytotoxic effect on NA cells, an epithelial cancer cell line. When NA cells were killed by SNP, high levels of NO2- (stable end product of NO) were detected in the culture medium. The cell death induced by SNP was mediated by apoptosis, as demonstrated by the presence of nuclear condensation and blebbing of the nuclear membrane, and internucleosomal DNA fragmentation quantified by a specific ELISA. Northern blot analysis revealed that c-myc mRNA expression of NA cells was rapidly reduced by treatment with SNP. RT-PCR analysis showed that c-myb mRNA was expressed in untreated NA cells, and c-myb mRNA level of NA cells was dose-dependently reduced by treatment with SNP. These results indicate that SNP exerts its cytotoxic effect on NA cells through spontaneous release of NO. Cytotoxicity induced by SNP is at least partially mediated via the process known as apoptosis. Our results also suggest that down-regulation of c-myc and c-myb proto-oncogenes might be involved in SNP-induced cytotoxicity.