Prognostic nomogram for nonresectable pancreatic cancer treated with gemcitabine-based chemotherapy

Background:

A nomogram is progressively being used as a useful predictive tool for cancer prognosis. A nomogram to predict survival in nonresectable pancreatic cancer treated with chemotherapy has not been reported.

Methods:

Using prospectively collected data on patients with nonresectable pancreatic cancer receiving gemcitabine-based chemotherapy at five Japanese hospitals, we derived a predictive nomogram and internally validated it using a concordance index and calibration plots.

Results:

In total, 531 patients were included between June 2001 and February 2013. The American Joint Committee on Cancer (AJCC) TNM stages were III and IV in 204 and 327 patients, respectively. The median survival time of the total cohort was 11.3 months. A nomogram was generated to predict survival probabilities at 6, 12, and 18 months and median survival time, based on the following six variables: age; sex; performance status; tumour size; regional lymph node metastasis; and distant metastasis. The concordance index of the present nomogram was higher than that of the AJCC TNM staging system at 12 months (0.686 vs 0.612). The calibration plots demonstrated good fitness of the nomogram for survival prediction.

Conclusions:

The present nomogram can provide valuable information for tailored decision-making early after the diagnosis of nonresectable pancreatic cancer.

Insulin-induced c-Jun N-terminal kinase activation is negatively regulated by protein kinase C delta

We investigated the role of protein kinase C (PKC) in insulin-induced c-Jun N-terminal kinase (JNK) activation in rat 1 fibroblasts expressing human insulin receptors. Insulin treatment led to increased SAPK/ERK kinase 1 (SEK1) phosphorylation, and then stimulated JNK activity in a dose- and time-dependent manner, as measured either by a solid-phase kinase assay using glutathione S-transferase (GST)-c-Jun fusion protein as a substrate, or by quantitation of the levels of phosphorylated JNK by Western blotting using anti-phospho-JNK antibody. Insulin-induced JNK activation was potentiated by either preincubating cells with 2 nM GF109203X (PKC inhibitor) or down-regulation of PKC by overnight treatment with 100 nM tetradecanoyl phorbol acetate. In contrast, brief preincubation with 100 nM tetradecanoyl phorbol acetate inhibited the insulin- induced JNK activation. Furthermore, we found that 5 microM rottlerin, a PKCdelta inhibitor, enhanced insulin-induced JNK activation, but a PKCbeta inhibitor, LY333531, had no effect. Consistent with these findings, overexpression of PKCdelta led to decreased insulin-induced JNK activation, whereas overexpression of PKCbeta had no effect. Although overexpression of wild-type PKCdelta attenuated insulin-induced JNK activation, a kinase-dead PKCdelta mutant did not cause such attenuation. Finally, we found that the magnitude of insulin-induced JNK activation was inversely correlated with the expression level of PKCdelta among different cell lines. In conclusion, the expression of PKCdelta may negatively regulate insulin-induced JNK activation.

Vascular endothelial growth factor induces expression of connective tissue growth factor via KDR, Flt1, and phosphatidylinositol 3-kinase-akt-dependent pathways in retinal vascular cells

Fibroblastic proliferation accompanies many angiogenesis-related retinal and systemic diseases. Since connective tissue growth factor (CTGF) is a potent mitogen for fibrosis, extracellular matrix production, and angiogenesis, we have studied the effects and mechanism by which vascular endothelial growth factor (VEGF) regulates CTGF gene expression in retinal capillary cells. In our study, VEGF increased CTGF mRNA levels in a time- and concentration-dependent manner in bovine retinal endothelial cells and pericytes, without the need of new protein synthesis and without altering mRNA stability. VEGF activated the tyrosine receptor phosphorylation of KDR and Flt1 and increased the binding of phosphatidylinositol 3-kinase (PI3-kinase) p85 subunit to KDR and Flt1, both of which could mediate CTGF gene induction. VEGF-induced CTGF expression was mediated primarily by PI3-kinase activation, whereas PKC and ERK pathways made only minimal contributions. Furthermore, overexpression of constitutive active Akt was sufficient to induce CTGF gene expression, and inhibition of Akt activation by overexpressing dominant negative mutant of Akt abolished the VEGF-induced CTGF expression. These data suggest that VEGF can increase CTGF gene expression in bovine retinal capillary cells via KDR or Flt receptors and the activation of PI3-kinase-Akt pathway independently of PKC or Ras-ERK pathway, possibly inducing the fibrosis observed in retinal neovascular diseases.

Induction of endothelin-1 expression by glucose: an effect of protein kinase C activation

Enhanced actions or levels of endothelin-1 (ET-1), a potent vasoconstrictor, have been associated with decreased blood flow in the retina and peripheral nerves of diabetic animals and may be related to the development of pathologies in these tissues. Hyperglycemia has been postulated to increase ET-1 secretion in endothelial cells. We have characterized the mechanism by which elevation of glucose is increasing ET-1 mRNA expression in capillary bovine retinal endothelial cells (BREC) and bovine retinal pericytes (BRPC). Elevation of glucose, but not mannitol, from 5.5 to 25 mmol/l for 3 days increased membranous protein kinase C (PKC) activities and ET-1 mRNA in parallel levels by 2-fold in BREC and BRPC. These effects were reversed by decreasing glucose levels to 5.5 mmol/l for an additional 2 days. Glucose-induced ET-1 overexpression was inhibited by a general PKC inhibitor, GF109203X, and a mitogen-activated protein kinase kinase inhibitor, PD98059, but not by wortmannin, a phosphatidylinositol 3-kinase inhibitor. By immunoblot analysis, PKC-beta2 and -delta isoforms in BREC were significantly increased relative to other isoforms in the membranous fractions when glucose level was increased. Overexpression of PKC-beta1 and -delta isoforms but not PKC-zeta isoform by adenovirus vectors containing the respective cDNA enhanced in parallel PKC activities, proteins, and basal and glucose-induced ET-1 mRNA expression by at least 2-fold. These results showed that enhanced ET-1 expression induced by hyperglycemia in diabetes is partly due to activation of PKC-beta and -delta isoforms, suggesting that inhibition of these PKC isoforms may prevent early changes in diabetic retinopathy and neuropathy.

Induction of endothelin-1 expression by glucose: an effect of protein kinase C activation

Enhanced actions or levels of endothelin-1 (ET-1), a potent vasoconstrictor, have been associated with decreased blood flow in the retina and peripheral nerves of diabetic animals and may be related to the development of pathologies in these tissues. Hyperglycemia has been postulated to increase ET-1 secretion in endothelial cells. We have characterized the mechanism by which elevation of glucose is increasing ET-1 mRNA expression in capillary bovine retinal endothelial cells (BREC) and bovine retinal pericytes (BRPC). Elevation of glucose, but not mannitol, from 5.5 to 25 mmol/l for 3 days increased membranous protein kinase C (PKC) activities and ET-1 mRNA in parallel levels by 2-fold in BREC and BRPC. These effects were reversed by decreasing glucose levels to 5.5 mmol/l for an additional 2 days. Glucose-induced ET-1 overexpression was inhibited by a general PKC inhibitor, GF109203X, and a mitogen-activated protein kinase kinase inhibitor, PD98059, but not by wortmannin, a phosphatidylinositol 3-kinase inhibitor. By immunoblot analysis, PKC-beta2 and -delta isoforms in BREC were significantly increased relative to other isoforms in the membranous fractions when glucose level was increased. Overexpression of PKC-beta1 and -delta isoforms but not PKC-zeta isoform by adenovirus vectors containing the respective cDNA enhanced in parallel PKC activities, proteins, and basal and glucose-induced ET-1 mRNA expression by at least 2-fold. These results showed that enhanced ET-1 expression induced by hyperglycemia in diabetes is partly due to activation of PKC-beta and -delta isoforms, suggesting that inhibition of these PKC isoforms may prevent early changes in diabetic retinopathy and neuropathy.

Mechanisms of hepatocyte growth factor-induced retinal endothelial cell migration and growth

PURPOSE

Hepatocyte growth factor (HGF), also called scatter factor, stimulates growth and motility in nonocular endothelial cells and smooth muscle cells through its receptor c-Met. Recent reports suggest that HGF is increased in the serum and vitreous of patients with proliferative diabetic retinopathy and that smooth muscle cells and retinal pigment epithelial cells secrete HGF in the eye. However, little is known about HGF's action in the retina. In this study, the activity, expression, and signaling pathways of HGF were investigated in bovine retinal microvascular endothelial cells (BRECs).

METHODS

Mitogenic and motogeneic effects of HGF on BRECs were examined using cell counts, thymidine uptake, and migration assays. MAP kinase (MAPK) phosphorylation was examined by Western blot analysis. Protein kinase C (PKC), MAPK, and PI3 kinase involvement were evaluated using selective inhibitors and activity assays. Expression of HGF and c-Met was evaluated by reverse transcription-polymerase chain reaction.

RESULTS

HGF and c-Met were both expressed in BRECs. HGF stimulated BREC growth in a time- and dose-dependent manner, observed at HGF concentrations of 5 ng/ml or more and maximal (410%) at 100 ng/ml (P < 0.001). HGF increased BREC migration in a dose-dependent manner with a maximal 3.4-fold increase at 50 ng/ml after 5 hours. HGF induced time- and dose-dependent MAPK phosphorylation, initially evident at 5 minutes (P < 0.001) or 5 ng/ml (P < 0.050) and maximal after 15 minutes (>80-fold, P < 0.001) or 50 ng/ml (>20-fold, P < 0.001), respectively. MAPK phosphorylation was maintained for more than 2 hours. This response was inhibited 31% by 0.1 microm wortmannin and 76% by 30 microm LY294002, another PI3 kinase inhibitor. The non-isoform-selective PKC inhibitor GFX inhibited HGF-induced MAPK phosphorylation by only 15% at 5 microm. Combined PKC and PI3 kinase inhibition was additive (P < 0.05). Cell migration was inhibited 30% by wortmannin (P < 0.01) and 32% by GFX (P < 0.05), and again the effect was additive (P < 0.001). HGF-induced BREC growth was suppressed by PI3 kinase, PKC, or MAPK inhibition (all P < 0.01). HGF (50 ng/ml) stimulated PI3 kinase activity 347% (P < 0.001) and PKC activity 37% (P < 0.05). HGF-induced MAPK phosphorylation and mitogenesis were not inhibited by vascular endothelial growth factor (VEGF)-neutralizing antibody.

CONCLUSIONS

HGF and its receptor are expressed in BREC, and HGF stimulates both BREC growth and migration at concentrations observed in the human eye with diabetic retinopathy. HGF signaling appears to involve activation of both PKC and PI3 kinase, inducing MAPK phosphorylation that is critical for migration and growth. However, VEGF does not appear to mediate these initial HGF effects. These results indicate that HGF could have a significant role in mediating retinal endothelial cell proliferation and migration in diabetic retinopathy, and they begin to elucidate the signal transduction pathway by which this action may occur.

IDL can stimulate atherogenic gene expression in cultured human vascular endothelial cells

Previously, we have reported that the lipoprotein fraction containing intermediate density lipoprotein (IDL) and low density lipoprotein (LDL) isolated from diabetics stimulates an atherogenic cytokine in cultured endothelial cells. To study which lipoprotein fraction isolated from diabetics can modulate the gene expression in endothelial cells, we isolated IDL and LDL fractions from 14 type 2 diabetics and seven age- and BMI- adjusted non-diabetics. We measured the effects of the lipoproteins on mRNA expression of atherogenic molecules in cultured endothelial cells. We found that the IDL fraction stimulated monocyte chemoattractant protein-1 (MCP-1) mRNA expression in endothelial cells as time- and dose-dependent fashions, while the LDL fraction was not effective. IDL isolated from diabetics also increased not only platelet-derived growth factor B-chain, but also intercellular adhesion molecule-1 mRNA contents. Furthermore, the HbA(1c) levels in diabetics were significantly correlated with their abilities of IDL to increase MCP-1 mRNA content in the cells and the increment coincided with the increase in MCP-1 protein release into culture media. These results indicate that qualitative as well as quantitative changes in IDL fraction in diabetes are atherogenic through stimulating gene expression of atherogenic molecules in endothelial cells.

Regulation of endothelial constitutive nitric oxide synthase gene expression in endothelial cells and in vivo : a specific vascular action of insulin

BACKGROUND

The vasodilatory effect of insulin can be acute or increase with time from 1 to 7 hours, suggesting that insulin may enhance the expression of endothelial nitric oxide synthase (eNOS) in endothelial cells. The objective of the present study was to characterize the extent and signaling pathways by which insulin regulates the expression of eNOS in endothelial cells and vascular tissues.

METHODS AND RESULTS

Physiological concentrations of insulin (10(-10) to 10(-7) mmol/L) increased the levels of eNOS mRNA, protein, and activity by 2-fold after 2 to 8 hours of incubation in cultured bovine aortic endothelial cells. Insulin enhanced eNOS gene expression in microvessels isolated from Zucker lean rats but not from insulin-resistant Zucker fatty rats. Inhibitors of phosphatidylinositol-3 kinase (PI-3 kinase) decreased the effect of insulin on eNOS gene expression, but a general protein kinase C (PKC) inhibitor, GF109203X or PKCbeta isoform inhibitor, LY333531 enhanced eNOS expression. In contrast, PKC activators inhibited both the activation by insulin of PI-3 kinase and eNOS mRNA levels. Overexpression of PKCbeta isoform in endothelial cells inhibited the stimulation by insulin of eNOS expression and PI-3 kinase activities in parallel.

CONCLUSIONS

Insulin can regulate the expression of eNOS gene, mediated by the activation of PI-3 kinase, in endothelial cells and microvessels. Thus, insulin may chronically modulate vascular tone. The activation of PKC in the vascular tissues as in insulin resistance and diabetes may inhibit PI-3 kinase activity and eNOS expression and may lead to endothelial dysfunctions in these pathological states.

Overexpression of core 2 N-acetylglycosaminyltransferase enhances cytokine actions and induces hypertrophic myocardium in transgenic mice

Elevated levels of glycocojugates, commonly observed in the myocardium of diabetic animals and patients, are postulated to contribute to the myocardial dysfunction in diabetes. Previously, we reported that UDP-GlcNAc: Galbeta1-3GalNAcalphaRbeta1-6-N-acetylglucosaminyltransferas e (core 2 GlcNAc-T), a developmentally regulated enzyme of O-linked glycans biosynthesis pathway, is specifically increased in the heart of diabetic animals and is regulated by hyperglycemia and insulin. In this study, transgenic mice overexpressing core 2 GlcNAc-T with severe increase in cardiac core 2 GlcNAc-T activities were normal at birth but showed progressive and significant cardiac hypertrophy at 6 months of age. The heart of transgenic mice showed elevation of sialylated O-glycan and increases of c-fos gene expression and AP-1 activity, which are characteristics of cardiac stress. Furthermore, transfection of PC12 cells with core 2 GlcNAc-T also induced c-fos promoter activation, mitogen activated-protein kinase (MAPK) phosphorylation, Trk receptor glycosylation, and cell differentiation. These results suggested a novel role for core 2 GlcNAc-T in the development of diabetic cardiomyopathy and modulation of the MAP kinase pathway in the heart.-Koya, D., Dennis, J. W., Warren, C. E., Takahara, N., Schoen, F. J., Nishio, Y., Nakajima, T., Lipes, M. A., King, G. L. Overexpression of core 2 N-acetylglycosaminyltransferase enhances cytokine actions and induces hypertrophic myocardium in transgenic mice.

Glucose or diabetes activates p38 mitogen-activated protein kinase via different pathways

Hyperglycemia can cause vascular dysfunctions by multiple factors including hyperosmolarity, oxidant formation, and protein kinase C (PKC) activation. We have characterized the effect of hyperglycemia on p38 mitogen-activated protein (p38) kinase activation, which can be induced by oxidants, hyperosmolarity, and proinflammatory cytokines, leading to apoptosis, cell growth, and gene regulation. Glucose at 16.5 mM increased p38 kinase activity in a time-dependent manner compared with 5.5 mM in rat aortic smooth muscle cells (SMC). Mannitol activated p38 kinase only at or greater than 22 mM. High glucose levels and a PKC agonist activated p38 kinase, and a PKC inhibitor, GF109203X, prevented its activation. However, p38 kinase activation by mannitol or tumor necrosis factor-alpha was not inhibited by GF109203X. Changes in PKC isoform distribution after exposure to 16.5 mM glucose in SMC suggested that both PKC-beta2 and PKC-delta isoforms were increased. Activities of p38 kinase in PKC-delta- but not PKC-beta1-overexpressed SMC were increased compared with control cells. Activation of p38 kinase was also observed and characterized in various vascular cells in culture and aorta from diabetic rats. Thus, moderate hyperglycemia can activate p38 kinase by a PKC-delta isoform-dependent pathway, but glucose at extremely elevated levels can also activate p38 kinase by hyperosmolarity via a PKC-independent pathway.

Portal hypertensive enteropathy in biliary atresia

This paper describes a rare case of biliary atresia (BA) in which massive postoperative bleeding developed due to portal hypertensive enteropathy. A 15-year-old boy had been doing well after Kasai's operation for BA. At around the age of 6 years he developed recurrent episodes of esophageal variceal bleeding and underwent esophageal transection, splenectomy, sclerotherapy, and embolization of the left gastric vein. At the age of 15 years he suddenly developed abdominal pain, hematemesis, and massive tarry stools. His hemoglobin level was 6.3 g/dl. Endoscopy showed several small, polypoid lesions in the jejunum beyond Treitz' ligament. The source of the bleeding was one of these lesions located in the proximal jejunojejunostomy of the Roux-en-Y loop. Because he had repeated episodes of melena, he underwent partial resection of the jejunum under endoscopic guidance. He has since been free of gastrointestinal (GI) bleeding. From this experience, we conclude that the polypoid lesions of an enteropathy may be a cause of massive GI bleeding in the postoperative portal hypertension of BA.

Heterogeneity of protein profiles of Helicobacter pylori isolated from individual patients

BACKGROUND

In order to characterize the diversity of Helicobacter pylori (H. pylori) in infected individuals, 10 colonies of H. pylori were isolated from the gastric juice of 25 patients with gastroduodenal diseases (total 250 isolates).

METHODS

Protein profiles of isolates were compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Results were confirmed by Western blotting (immunoblotting) test using rabbit antisera against three different strains of H. pylori.

RESULTS

The protein profiles of 18 of 25 cases (72%) showed a single type of H. pylori with the same polypeptide pattern. In contrast, heterogeneity in the protein profiles was seen in isolates from seven cases (28%). Two differing H. pylori types with two very different polypeptide patterns were found in 10 isolates from one case. In six patients, the protein profiles of isolates were found to have variations in their polypeptides between molecular weights of 30,000 (30K) and 14K, which are thought to be associated with bacterial membrane protein. In some isolates, a polypeptide band of the 16K was missing. Each of three different antisera confirmed differences among the distinct isolates from individual patients.

CONCLUSIONS

These findings suggest that more than one antigenically different strain of H. pylori may exist in same infected individuals.

Colonoscopic diagnosis of lymphoid hyperplasia causing recurrent intussusception: report of a case

This paper describes a 6-year-old boy with recurrent ileocecal intussusception due to lymphoid hyperplasia in the terminal ileum, which was diagnosed preoperatively by colonoscopy. At the age of 3 years, he developed diarrhea and a tender abdominal mass. He was diagnosed as having intussusception by ultrasound and was treated by hydrostatic barium enema. After resolution, he had three recurrent episodes of intussusception. A contrast barium enema revealed a small mass in the ileocecal region. Colonoscopy showed several exaggerated folds of the terminal ileum and a biopsy showed lymphoid hyperplasia. Because the repeated intussusception seemed to have been caused by the lymphoid hyperplasia in the terminal ileum, he underwent an ileocecal resection without any subsequent recurrence. Based on the above findings, we conclude that a colonoscopy may thus be useful both for diagnosing lymphoid hyperplasia in the terminal ileum as a cause of recurrent intussusception and for deciding how to manage it.

Pyruvate improves deleterious effects of high glucose on activation of pentose phosphate pathway and glutathione redox cycle in endothelial cells

In our previous study (Diabetes 44:520-526, 1995), endothelial cells cultured in high glucose condition showed impairment of an oxidant-induced activation of the pentose phosphate pathway (PPP) and a reduced supply of NADPH to the glutathione redox cycle. To gain insight into the mechanisms of this impairment, the protective effect of pyruvate was studied in human umbilical vein endothelial cells cultured in either 5.5 mmol/l glucose (normal glucose [NG] condition) or 33 mmol/l glucose (high glucose [HG] condition). Through pretreatment of cells with 0.2 mmol/l pyruvate for 5-7 days in the HG condition, glucose oxidation through the PPP and total cellular NADPH content in the presence of 0.2 mmol/l H2O2 were increased by 54 (P < 0.05) and 34%, respectively, and glutathione-dependent degradation of H2O2 in HG cells was enhanced by 41% (P < 0.01), when compared with those cells to which pyruvate was not added. The addition of pyruvate significantly reduced the fructose 1,6-bisphosphate (FDP) content and free cytoplasmic NADH/NAD ratio, estimated by increased pyruvate/lactate ratio in NG and HG cells exposed to H2O2. Furthermore, the addition of pyruvate also showed a 46% reduction (P < 0.01) of endothelial cell damage induced by H2O2 in HG cells. These results indicate that abnormalities in PPP activation and glutathione redox cycle activity induced by H2O2 in HG cells are compensated, and that the accentuated reductive stress is improved by an addition of pyruvate. These pyruvate effects are associated with protection against an oxidant-induced endothelial cell injury in the high glucose condition.

Cilostazol, a cAMP phosphodiesterase inhibitor, attenuates the production of monocyte chemoattractant protein-1 in response to tumor necrosis factor-alpha in vascular endothelial cells

The induction of monocyte chemoattractant protein-1 (MCP-1) in vascular endothelial cells is thought to be an initial event in the development of atherosclerotic lesions. Therefore, inhibition of MCP-1 production may exhibit some effects in preventing atherosclerosis. In the present study, we found that 10 microM cilostazol, a cAMP phosphodiesterase inhibitor, increased the intracellular cAMP content by a twenty-five times of the basal level and resulted in the reduction of basal MCP-1 release by 41% from 168 +/- 11 ng/24 hr/mg protein to 99 +/- 14 ng/24 hr/mg protein (P < 0.001) from cultured human umbilical vein endothelial cells. Furthermore, 10 microM cilostazol also significantly attenuated the dose-dependent increment of MCP-1 production by tumor necrosis factor-alpha. The inhibition was consistent with the reduction of MCP-1 mRNA level, possibly through reduced activation of transcription factor NF-kappa B level. Similarly, 1 mM dibutyryl cAMP inhibited MCP-1 production in endothelial cells. These data suggest that cilostazol inhibits MCP-1 production through increased intracellular cAMP levels and modulation of its expression in vascular endothelial cells.

Oxidized lipoproteins found in patients with NIDDM stimulate radical-induced monocyte chemoattractant protein-1 mRNA expression in cultured human endothelial cells

Although oxidized low density lipoprotein (LDL) exists in plasma from diabetic patients, there are few studies on its biological activity. Thus, we investigated the biological potency of LDL plus intermediate density lipoprotein fraction isolated from 12 non-diabetic and 24 non-insulin-dependent diabetic subjects of similar age and body mass index, in order to induce monocyte chemoattractant protein-1 (MCP-1) mRNA expression in cultured human endothelial cells. MCP-1 mRNA content in the cells exposed to the lipoproteins isolated from the diabetic patients was significantly higher than that from the control subjects (p < 0.001). The increment of MCP-1 mRNA content was positively correlated with not only HbA1c (r = 0.58, p < 0.0001) but also lysophosphatidylcholine (LPC) content in the lipoprotein (r = 0.46, p < 0.005) and was negatively correlated with diene formation lag time as a marker of oxidizability of the lipoprotein (r = -0.33, p < 0.05). Treatments of the cells with either 50 mumol/l probucol, 50 mumol/l alpha-tocopherol, or 0.1 mmol/l deferoxamine suppressed the increase in MCP-1 mRNA content induced by diabetic lipoproteins, respectively. Furthermore, the diabetic lipoproteins activated nuclear transcription factor NF-kappa B in the cells, which was inhibited by pre-treatment of cells with 50 mumol/l probucol. These data indicate that oxidatively modified lipoproteins found in diabetic plasma stimulate MCP-1 gene expression in endothelial cells. The LPC content which reflects oxidative modification of lipoprotein is at least a possible marker of biological activity to increase an atherogenic cytokine in endothelial cells.

Lysophosphatidylcholine stimulates the expression and production of MCP-1 by human vascular endothelial cells

Lysophosphatidylcholine (LPC increased monocyte chemoattractant protein-1 (MCP-1) messenger RNA concentrations in human umbilical vein endothelial cells (HUVECs). A time-course study showed that the increase in MCP-1 mRNA levels peaked at 6 hours after treatment with LPC. The effect of LPC on the accumulation of MCP-I mRNA levels in HUVECs depended on LPC concentration, and the maximal effect was obtained at 50 micromol / L LPC, which induced a sixfold increase in MCP-1 mRNA levels. The amount of MCP-1 released from HUVECs measured using an enzyme-linked immunosorbent assay (ELISA) showed a 38% increase in the presence of 50 micromol/L LPC, but not in the presence of phosphatidylcholine or lysophosphatidylethanolamine. Coincubation with staurosporine, a potent inhibitor of protein kinase C (PKC) activity, attenuated the LPC-induced increase in MCP-1 mRNA levels by 53%. These results indicate that LPC can induce an increase in MCP-1 mRNA concentrations and stimulate the release of MCP-1 protein from HUVECs, and that the effect of LPC on the MCP-1 gene may be mediated through activation of the PKC pathway.

Src homology 2 domains of protein tyrosine phosphatase are phosphorylated by insulin receptor kinase and bind to the COOH-terminus of insulin receptors in vitro

To clarify the role of protein tyrosine phosphatases(PTPase) containing Src homology 2 (SH2) regions on insulin signaling, we investigated the interactions between SH2 regions of PTPase and insulin receptors. We made a pair of SH2 domains of PTP1C and SH-PTP2 fusion proteins coupled to glutathione-S-transferase (GST) using pGEX-3X expression vector. After incubating with insulin, insulin receptors were incubated with SH2 proteins in the presence of 100 mu ATP at 4 degrees C for 3 hr, and then immunoprecipitated and analyzed by SDS-PAGE. We found that SH2 domains of SH-PTP2 were phosphorylated, but not those of PTP1C by insulin receptor kinase and the SH2 domains of SH-PTP2, but not those of PTP1C, directly bound to the phosphorylated COOH-terminus of insulin receptors in vitro.

[Split rib cranioplasty]

Presented are an operative technique and clinical indications for split rib cranioplasty, and the results of its practical application. This technique was applied to 6 patients, in five of whom infection after previous cranioplasty had been noted before split rib cranioplasty. Two patients out of the 5 had been suffering from inveterate and repetitive postoperative infections; one patient had been operated on twice and the other three times, respectively. Operative results were excellent without serious and/or infectious complications, except initially in one patient who presented hemothorax after rib harvest. This method can be applied for those who have extensive defect of the skull or who need additional reconstruction using split rib graft because of infectious complications after previously performed cranioplasty. This technique also has the following advantage; cranial contour is easy to reconstruct and good cosmetic results can be expected.

[Angiographic classification for the selection of treatment of spontaneous carotid-cavernous sinus fistula]

Sixteen cases of spontaneous carotid-cavernous sinus fistula treated in our clinic were angiographically classified into four types, based on the report by Barrow et al; Type A: direct shunts between the internal carotid artery (ICA) and the cavernous sinus (CS), Type B: dural shunts between meningeal branches of the ICA and the CS, Type C: dural shunts between meningeal branches of the external carotid artery (ECA) and the CS, type D: dural shunts between meningeal branches of both the ICA and ECA and the CS. Our fundamental modality of treatment for each type was described as follows; detachable balloon occlusion of fistula was performed for Type A immediately after the diagnosis was confirmed. On the other hand, conservative treatment was selected at first routinely for Type B, C and D with administration of hemostatic agents, control of the blood pressure and Matas test for a certain period. This selection was made because the latter three types sometimes showed a high rate of spontaneous regression of symptoms. Only when no improvement was obtained by conservative therapy with Type B, C and D, the following treatments were adopted respectively; Type B: irradiation----detachable balloon occlusion of fistula, Type C: embolization through ECA, Type D: embolization through ECA----irradiation.

Induction of alkaline phosphatase activity in cultured human intracranial tumor cells

Alkaline phosphatase activity in several cultured primary human intracranial tumor cells varied over a relatively wide range, and there was no correlation between specific activity and the type of tumor from which the cultures were derived. The enzyme was thermolabile, and its activity was strongly inhibited by l-bromotetramisole, levamisole, and L-homoarginine but not by L-phenylalanine and L-phenylalanyglycylglycine. These are the characteristics of the liver-bone-kidney form of alkaline phosphatase. Prednisolone induced increased levels of enzyme activity in most cultures, and sodium butyrate acted as an inducer in cultures of pituitary adenoma and hemangioblastoma cells. The increase was most pronounced when response cells were exposed to both stimuli simultaneously. The induced alkaline phosphatase had the same properties as the enzyme of cells grown in the absence of inducers. Increased alkaline phosphatase activity was not induced by osmolality changes of the culture medium; this feature appears to be characteristic of cells producing the liver-bone-kidney enzyme form.

Alkaline phosphatase activity in cultured meningioma cells

The specific activity of alkaline phosphatase in cultured human meningioma cells varies over a relatively wide range. There is no correlation between the levels of activity and the histological type of meningioma from which the cultures were derived. The enzyme is heat-labile and is strongly inhibited by L-homoarginine, levamisole, and 1-bromotetramisole, but unaffected by L-phenylalanine and L-phenylalanyl-glycylglycine. These findings indicate that meningioma cells synthesize the liver/bone/kidney form of alkaline phosphatase. In contrast to cultures derived from pituitary adenomas, glioblastomas, and astrocytomas in which prednisolone and/or sodium butyrate elicit a manifold increase of alkaline phosphatase activity, with meningioma cells the hormone causes only a slight augmentation in specific activity, and the fatty acid is ineffective. As with other cells producing the liver/bone/kidney enzyme form, no increase in activity occurs in meningioma cells growing in hyperosmolar medium.