Biomedical subjects

M Shibuya

Publications and source records attributed to M Shibuya.

At least 127 records · Page 7Linked to original sources

PubMed1999

[Angiogenesis--vascular endothelial growth factor and its receptors].

Angiogenesis is a crucial biological process not only in the formation of cardiovascular system and organization of tissues in embryo but also in a variety of diseases including solid tumor growth and diabetic retinopathy. Several protein factors crucial for regulation of angiogenesis have recently been identified. Among these factors, VEGF is considered to be the most important regulator for vascular endothelial cell growth and differentiation both in physiological and pathological conditions. Relationship between VEGF and other regulatory factors such as Angiopoietins should be elucidated to further understand the dynamic process of angiogenesis.

Animals↗

PubMed1999

[Ultrasonogram of carotid artery in endoarterectomy patients].

Ultrasonograms of the carotid artery were compared with the intraoperative finding of atheroma plaque in terms of stenosis, fragility, ulceration and calcification. Soft type, intermediate type and these mixed type plaques were fragile plaques in almost all cases. All hard type plaques were tough plaques. The detection of stenosis and calcification was satisfactory, however that of ulceration was not sufficient. The stenotic lesions frequently existed in bilateral carotid arteries and the intima was easy to become thick even after the endoarterectomy. The ultrasonogram was thought to be the essential study for the carotid artery lesions.

Aged↗

PubMed1998

A novel type of vascular endothelial growth factor, VEGF-E (NZ-7 VEGF), preferentially utilizes KDR/Flk-1 receptor and carries a potent mitotic activity without heparin-binding domain.

Vascular endothelial growth factor (VEGF) mediates endothelial cell proliferation, angiogenesis, and vascular permeability via the endothelial cell receptors, KDR/Flk-1 and Flt-1. Recently, a gene encoding a polypeptide with about 25% amino acid identity to mammalian VEGF was identified in the genome of Orf virus (OV), a parapoxvirus that affects sheep and goats and occasionally, humans, to generate lesions with angiogenesis. In this study, we examined the biological activities and receptor of OV-derived NZ-7 VEGF (VEGF-E). VEGF-E was found to be a dimer of about 20 kDa with no basic domain nor affinity for heparin column, similar to VEGF121 subtype. VEGF121 has 10-100-fold less endothelial cell mitotic activity than VEGF165 due to lack of a heparin-binding basic region. Interestingly, however, VEGF-E showed almost equal levels of mitotic activity on primary endothelial cells and vascular permeability activity as VEGF165. Furthermore, VEGF-E bound KDR/Flk-1 (VEGFR-2) and induced its autophosphorylation to almost the same extent as VEGF165, but did not bind Flt-1 (VEGFR-1) nor induce autophosphorylation of Flt-1. These results indicate that VEGF-E is a novel type of endothelial growth factor, utilizing only one of the VEGF receptors, and carrying a potent mitogenic activity without affinity to heparin.

Animals↗

PubMed1998

Mapping of the sites involved in ligand association and dissociation at the extracellular domain of the kinase insert domain-containing receptor for vascular endothelial growth factor.

The kinase insert domain-containing receptor (KDR) for vascular endothelial growth factor (VEGF) has been shown to be involved in vasculogenesis and angiogenesis. This receptor is characterized by seven immunoglobulin (Ig)-like domains within its extracellular region. To identify the domains involved in VEGF binding, we constructed various deletion mutants of the extracellular region fused with the crystallizable fragment portion of an IgG and then examined the binding affinity with VEGF by means of the BIAcore biosensor assay. Deletion of the COOH-terminal two or three Ig-like domains out of a total of seven affected ligand dissociation rather than association. Further deletion of the fourth domain caused a drastic decrease in the association rate. Binding ability was abolished completely with removal of the third domain. The mutant KDR proteins lacking the NH2-terminal Ig-like domain exhibited a slightly higher association rate compared with those of the mutants having this domain. Deletion of the first two NH2-terminal Ig-like domains caused a drastic reduction in the association rate, but affinity to VEGF was retained. These results suggest that the third Ig-like domain is critical for ligand binding, the second and fourth domains are important for ligand association, and the fifth and sixth domains are required for retention of the ligand bound to the receptor molecule. The first Ig-like domain may regulate the ligand binding.

Binding Sites↗

PubMed1998

Vascular endothelial growth factor B (VEGF-B) binds to VEGF receptor-1 and regulates plasminogen activator activity in endothelial cells.

The vascular endothelial growth factor (VEGF) family has recently expanded by the identification and cloning of three additional members, namely VEGF-B, VEGF-C, and VEGF-D. In this study we demonstrate that VEGF-B binds selectively to VEGF receptor-1/Flt-1. This binding can be blocked by excess VEGF, indicating that the interaction sites on the receptor are at least partially overlapping. Mutating the putative VEGF receptor-1/Flt-1 binding determinants Asp63, Asp64, and Glu67 to alanine residues in VEGF-B reduced the affinity to VEGF receptor-1 but did not abolish binding. Mutational analysis of conserved cysteines contributing to VEGF-B dimer formation suggest a structural conservation with VEGF and platelet-derived growth factor. Proteolytic processing of the 60-kDa VEGF-B186 dimer results in a 34-kDa dimer containing the receptor-binding epitopes. The binding of VEGF-B to its receptor on endothelial cells leads to increased expression and activity of urokinase type plasminogen activator and plasminogen activator inhibitor 1, suggesting a role for VEGF-B in the regulation of extracellular matrix degradation, cell adhesion, and migration.

3T3 Cells↗

PubMed1998

Involvement of MAP kinase-independent protein kinase C signaling pathway in the EGF-induced p21(WAF1/Cip1) expression and growth inhibition of A431 cells.

Previous studies have revealed that the growth inhibition of A431 cells overexpressing epidermal growth factor (EGF) receptors by a high concentration of EGF is mainly due to the expression of cycline dependent kinase (CDK) inhibitor p21(WAF1/Cip1). However, the signal transduction mechanism from the activated EGF receptor to the induction of p21(WAF1/Cip1) gene is still poorly understood. We investigated which signaling pathway plays an important role in p21(WAF1/Cip1) expression and growth inhibition by using specific inhibitors of the signaling molecules. A broad PKC inhibitor, PKC delta inhibitor, but not the conventional PKC inhibitor suppressed the EGF-induced p21(WAF1/Cip1) expression and the growth inhibition of A431 cells. These inhibitors did not alter either the activation of EGF receptor or the stimulation of MAP kinase at detectable levels. Furthermore, we found that the induction of p21(WAF1/Cip1) at the early phase (within 12 hr after stimulation) by a high concentration of EGF was independent of the MAP kinase activation by using dominant negative Ras. These results suggest that PKC, especially PKC delta plays a crucial role in the EGF-induced p21(WAF1/Cip1) expression, resulting in the growth inhibition of A431 cells.

Calcium-Calmodulin-Dependent Protein Kinases↗

PubMed1998

Neuropilin-1 is a placenta growth factor-2 receptor.

Placenta growth factor (PlGF) belongs to the family of vascular endothelial growth factors (VEGFs). It binds to the flt-1 VEGF receptor but not to the KDR/flk-1 receptor which is thought to mediate most of the angiogenic and proliferative effects of VEGF. Three PlGF isoforms are produced by alternative splicing. PlGF-1 and PlGF-3 differ from PlGF-2 since they lack the exon 6 encoded peptide which bestows upon PlGF-2 its heparin binding properties. Cross-linking experiments revealed that 125I-PlGF-2 binds to two endothelial cell surface receptors in a heparin dependent fashion. The binding of 125I-PlGF-2 to these receptors was inhibited by an excess of PlGF-2 and by the 165-amino acid form of VEGF (VEGF165), but not at all by VEGF121 and very marginally if at all by PlGF-1. The apparent molecular weight and the binding characteristics of these receptors correspond to those of the recently identified VEGF165 specific receptor neuropilin-1, and we therefore conclude that neuropilin-1 is a receptor for PlGF-2. The binding of 125I-PlGF-2 as well as the binding of 125I-VEGF165 to these receptors was inhibited by a synthetic peptide derived from exon 6 of PlGF. Furthermore, the binding of 125I-PlGF-2, but not that of 125I-VEGF165, was also inhibited by a synthetic peptide derived from exon 7 of PlGF. These observations indicate that the peptides encoded by these exons probably participate in the formation of the domain which mediates the binding of PlGF-2 to these receptors. We have also determined, using chemically modified heparin species, that the presence of sulfate moieties on the glucosamine-O-6 and on the iduronic acid-O-2 groups of heparin was required for the potentiation of 125I-PlGF-2 binding to these receptors. To determine if PlGF-2 is able to induce biological responses that are not induced by PlGF-1, we compared the effects of PlGF-1 and PlGF-2 on the migration and proliferation of endothelial cells. Both PlGF forms induced migration of endothelial cells. However, there was no quantitative difference between the response to PlGF-2 and the response to PlGF-1. Furthermore, neither PlGF-1 nor PlGF-2 had any effect upon the proliferation of the endothelial cells.

Animals↗

PubMed1998

Beta-amyrin synthase--cloning of oxidosqualene cyclase that catalyzes the formation of the most popular triterpene among higher plants.

Beta-amyrin, a typical pentacyclic triterpene having an oleanane skeleton, is one of the most commonly occuring triterpenes in nature and is biosynthesized from (3S)-2,3-oxidosqualene. The enzyme, beta-amyrin synthase, catalyzing the cyclization of oxidosqualene into beta-amyrin, generates five rings and eight asymmetric centers in a single transformation. A homology-based PCR method was attempted to obtain the cDNA of this enzyme from the hairy root of Panax ginseng which produces oleanane saponins together with dammarane-type saponins. Two sets of degenerate oligonucleotide primers were designed at the regions which are highly conserved among known oxidosqualene cyclases (OSCs). Nested PCRs using these primers successfully amplified the core fragment which revealed the presence of two OSC clones PNX and PNY. Specific amplification of each clone by 3'-RACE and 5'-RACE was carried out to obtain the whole sequences. The two clones exhibited 60% amino acid identity to each other. A full-length clone of PNY was ligated into the yeast expression vector pYES2 under the GAL1 promoter to give pOSC(PNY). Beta-amyrin production was observed with the mutant yeast lacking lanosterol synthase, transformed by this plasmid. The sequence of pOSC(PNY) contains an open reading frame of 2289 nucleotides which codes for 763 amino acids with a predicted molecular mass of 88 kDa. Sequence comparison with other OSCs showed a high level of similarity with lanosterol, cycloartenol and lupeol synthases. The other clone, pOSC(PNX), was shown to be cycloartenol synthase by similar expression in yeast. The present studies have revealed that distinct OSC exists for triterpene formation in higher plants, and the high level of similarity with cycloartenol synthase indicates close evolutional relationship between sterol and triterpene biosynthesis.

Amino Acid Sequence↗

PubMed1998

Flt-1 lacking the tyrosine kinase domain is sufficient for normal development and angiogenesis in mice.

Receptor tyrosine kinases Flt-1 and Flk-1/KDR, and their ligand, the vascular endothelial growth factor (VEGF), were shown to be essential for angiogenesis in the mouse embryo by gene targeting. Flk-1/KDR null mutant mice exhibited impaired endothelial and hematopoietic cell development. On the other hand, Flt-1 null mutation resulted in early embryonic death at embryonic day 8.5, showing disorganization of blood vessels, such as overgrowth of endothelial cells. Flt-1 differs from Flk-1 in that it displays a higher affinity for VEGF but lower kinase activity, suggesting the importance of its extracellular domain. To examine the biological role of Flt-1 in embryonic development and vascular formation, we deleted the kinase domain without affecting the ligand binding region. Flt-1 tyrosine kinase-deficient homozygous mice (flt-1(TK-/-)) developed normal vessels and survived. However, VEGF-induced macrophage migration was strongly suppressed in flt-1(TK-/-) mice. These results indicate that Flt-1 without tyrosine kinase domain is sufficient to allow embryonic development with normal angiogenesis, and that a receptor tyrosine kinase plays a main biological role as a ligand-binding molecule.

Animals↗

PubMed1998

Possible mechanism underlying the potent vasoconstrictor actions of cyclopiazonic acid on dog cerebral arteries.

A sustained Ca2+ influx via L-type Ca2+ channels has been shown in the resting state of dog cerebral arteries. Sarcoplasmic reticulum is now recognized to serve as a buffer barrier to Ca2+ entry in vascular smooth muscle cells. To clarify whether sarcoplasmic reticulum of the cerebral arteries can buffer the sustained Ca2+ influx, effects of cyclopiazonic acid (CPA), an inhibitor of sarcoplasmic reticulum Ca2+-ATPase, were determined in endothelium-denuded strips of the cerebral (basilar, posterior communicating, middle cerebral), mesenteric and coronary arteries of the dog. The addition of CPA (0.1-10 microM) during the resting state of the strips caused a concentration-dependent contraction in the three cerebral arteries. The CPA-induced contraction was extremely small in the mesenteric or coronary artery. The CPA-induced contractions in the cerebral arteries were inhibited concentration-dependently by nifedipine (1-100 nM). Nifedipine itself induced relaxation from the resting state of cerebral arteries, suggesting a maintenance of basal tone. The CPA-induced potent contraction seen in the cerebral arteries could be mimicked in the mesenteric artery by elevating the extracellular K+ concentration (14.9 mM) or adding Bay K 8644 [methyl-1,4-dihydro-2,6-dimethyl-3-nitro-4-(2-trifluoromethylphenyl)-pyr idine-5-carboxylate] (100 nM) to produce an increase in Ca2+ influx via L-type Ca2+ channels. We conclude that, in the resting state of dog cerebral arteries, (1) the greater part of the sustained Ca2+ influx is buffered by Ca2+ uptake into the sarcoplasmic reticulum, (2) therefore, the inhibition of sarcoplasmic reticulum Ca2+-ATPase by CPA causes a potent contraction, and (3) the maintenance of basal tone suggests that some Ca2+ that entered via L-type Ca2+ channels always reaches the myofilaments in the resting state.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

PubMed1998

Angiotensin II type 1 receptor-induced extracellular signal-regulated protein kinase activation is mediated by Ca2+/calmodulin-dependent transactivation of epidermal growth factor receptor.

The signaling cascade elicited by angiotensin II (Ang II) resembles that characteristic of growth factor stimulation, and recent evidence suggests that G protein-coupled receptors transactivate growth factor receptors to transmit mitogenic effects. In the present study, we report the involvement of epidermal growth factor receptor (EGF-R) in Ang II-induced extracellular signal-regulated kinase (ERK) activation, c-fos gene expression, and DNA synthesis in cardiac fibroblasts. Ang II induced a rapid tyrosine phosphorylation of EGF-R in association with phosphorylation of Shc protein and ERK activation. Specific inhibition of EGF-R function by either a dominant-negative EGF-R mutant or selective tyrphostin AG1478 completely abolished Ang II-induced ERK activation. Induction of c-fos gene expression and DNA synthesis were also abolished by the inhibition of EGF-R function. Calmodulin or tyrosine kinase inhibitors, but not protein kinase C (PKC) inhibitors or downregulation of PKC, completely abolished transactivation of EGF-R by Ang II or the Ca2+ ionophore A23187. Epidermal growth factor (EGF) activity in concentrated supernatant from Ang II-treated cells was not detected, and saturation of culture media with anti-EGF antibody did not affect the Ang II-induced transactivation of EGF-R. Conditioned media in which cells were incubated with Ang II could not induce phosphorylation of EGF-R on recipient cells. Platelet-derived growth factor-beta receptor was not phosphorylated on Ang II stimulation, and Ang II-induced c-jun gene expression was not affected by tyrphostin AG1478. Our results demonstrated that in cardiac fibroblasts Ang II-induced ERK activation and its mitogenic signals are dominantly mediated by EGF-R transactivated in a Ca2+/calmodulin-dependent manner and suggested that the effects of Ang II on cardiac fibroblasts should be interpreted in association with the signaling pathways regulating cellular proliferation and/or differentiation by growth factors.

Animals↗

PubMed1998

Differential inhibition of fluid accumulation and tumor growth in two mouse ascites tumors by an antivascular endothelial growth factor/permeability factor neutralizing antibody.

In the accompanying paper (Luo et al., Cancer Res., 58: 2652-2660, 1998), we demonstrated that vascular endothelial growth factor (VEGF), also designated vascular permeability factor (VPF), significantly accumulated in all mouse malignant ascites tested, suggesting its fundamental role in ascites tumors. Removal of VEGF may inhibit the development of ascites tumors. In this study, using a goat antimouse VEGF-neutralizing antibody, we tested this hypothesis with two well-defined syngeneic mouse ascites tumors: MM2 breast adenocarcinoma and OG/Gardner lymphoma 6C3HED (expressing moderate and low levels of VEGF, respectively). This antibody significantly inhibited MM2 and OG cell-free ascites fluid-induced hyperpermeability of mouse peritoneal microvessels and in vitro endothelial cell growth. Mice bearing tumors were administered i.p. daily with the antibody or normal goat IgG as controls for 8 days, at doses of 20-fold (for MM2-bearing mice) or 40-fold (for OG-bearing mice) the estimated amounts of VEGF that kinetically accumulated in the ascites fluid after the tumor inoculation. The average volume of ascites fluid, number of tumor cells and leaked RBCs, and the peritoneal microvessel permeability in MM2-bearing mice that received the antibody treatment were significantly lower than those in the matched controls (P < 0.01). Unexpectedly, OG-bearing mice did not show satisfactory response to the anti-VEGF treatment. This discrepancy was not likely due to inadequate doses or different host immune responses, but it was quite possibly to the different characteristics of MM2 carcinoma and OG lymphoma tumors, the latter being strongly invasive, and/or the existence of an inflammatory mediator(s), such as bradykinin or cytokine(s) other than VEGF. In summary, our results directly demonstrated, for the first time, differential roles for VEGF in ascites tumors in vivo and suggest the potential of VEGF inhibition as a specific therapy for ascites tumors of carcinoma origin, which are the major cause of the malignant ascites in adult humans.

Animals↗

PubMed1998

Significant expression of vascular endothelial growth factor/vascular permeability factor in mouse ascites tumors.

Vascular endothelial growth factor (VEGF), also known as vascular permeability factor, is believed to be a potent mediator of peritoneal fluid accumulation and angiogenesis and of tumor growth in ascites tumor. Such roles, however, have not been generally established because of insufficient quantitative and systemic analyses. To address this, we examined the expression of VEGF in 13 mouse ascites tumors (5 sarcomas, 3 carcinomas, 2 lymphomas, 1 leukemia, 1 mastocytoma, and 1 plasmacytoma). Using a newly developed sensitive and specific radioreceptor binding assay and functional assays, we found that active VEGF was significantly accumulated (6-850 ng/ml) in the ascites fluids of all 13 tumors. VEGF concentrations are higher in the tumors of sarcoma and carcinoma origin (430.4 +/- 234.2 ng/ml) than in those of lymphoma and hematological tumor origin (19.2 +/- 10.45 ng/ml). VEGF that accumulated in the peritoneal fluids or expressed in the ascites tumor cells was easily visualized with immunoprecipitation Western blot analysis with a rough correlation to the expression levels of VEGF gene in these tumor cells, suggesting that the tumor cells, at least in part, contributed to the production of the VEGF that accumulated in the ascites fluid. Most ascites tumors expressed VEGF; the 164-amino acid isoform was predominant, the 120-amino acid isoform was less abundant, and the 188-amino acid isoform was least abundant. Several representative ascites tumors expressed similar, if not higher, levels of VEGF when they were cultured at normoxic states, suggesting that they expressed VEGF at high levels in a constitutive manner. The microvessel densities in the peritoneal walls of tumor-bearing mice, which are significantly higher than those in normal mice, basically correlated to but did not parallel the VEGF concentrations in their respective ascites fluids. Thus, a complicated relationship may exist between the VEGF production and angiogenesis associated with ascites tumor in vivo. Taken together, our observations suggest that VEGF plays a fundamental role in ascites tumor formation; however, its importance may vary according to tumor origin.

Animals↗

PubMed1998

Genomic organization of the flt-1 gene encoding for vascular endothelial growth factor (VEGF) receptor-1 suggests an intimate evolutionary relationship between the 7-Ig and the 5-Ig tyrosine kinase receptors.

The flt-1 tyrosine kinase gene encodes a high affinity receptor for Vascular Endothelial Growth Factor, and belongs to the so-called '7-Ig' or flt gene family which has characteristics of 7-Immunoglobulin (Ig)-like domains in the extracellular region. This is structurally distantly related to 5-Ig domain-containing receptors such as Fms/Kit/PDGF-R. However, the whole genomic organization for any 7-Ig receptor gene has not been determined yet. To examine the genomic structure of flt-1 and the evolutionary relationship between genes of the 7-Ig and 5-Ig receptor families, we isolated the mouse genomic DNAs carrying all exons of the flt-1 gene. The mouse flt-1 gene consisted of 30 exons, whose exon-intron boundaries were highly related to those in the 5-Ig receptor genes, except for the amino terminal region. The sequences corresponding to the first and second Ig-domains in the flt-1 gene were encoded by four exons, whereas this region was encoded by only two exons in the 5-Ig receptor genes. These results raise the interesting possibility that deletion or insertion mutations of introns in one of these receptor genes took place in the evolutionary generation of the other receptor genes.

Amino Acid Sequence↗

PubMed1998

Mammary carcinoma cells over-expressing tissue inhibitor of metalloproteinases-1 show enhanced vascular endothelial growth factor expression.

The tissue inhibitor of metalloproteinases-1 (TIMP-1) has at least 2 independent functions, i.e., regulation of matrix metalloproteinases and erythroid-potentiating activity. We investigated the effects of TIMP-1 over-expression on tumor growth, using cloned lines derived from a TIMP-1-transfected rat breast carcinoma cell line. The in vitro growth rate of the TIMP-1-transfected clones was indistinguishable from that of the control. In contrast, the highest TIMP-1-producing clone (159.0 ng/ml), designated as T-H, formed 4.6-fold larger s.c. tumors than did the control after 14 days. Tumors derived from an intermediate TIMP-1-producing clone (45.4 ng/ml), designated as T-M, were 1.9-fold larger than the control. TIMP-1 over-expression was associated with increased vascular endothelial growth factor (VEGF) expression, vascularization and proliferative activity of the s.c. tumors. Similar to the rat breast carcinoma cells, transfection of TIMP-1 cDNA into the human breast carcinoma cell line MCF-7 resulted in up-regulation of VEGF, with a linear relationship between TIMP-1 and VEGF production in 9 cell clones examined. There was, however, no change in VEGF expression when the rat and human breast carcinoma cell lines were exposed to exogenous recombinant TIMP-1. Our findings suggest that over-expression of TIMP-1 confers growth advantage on breast carcinoma cells in vivo and that up-regulation of VEGF expression may play an important role in this TIMP-1-mediated, growth-stimulating effect.

Animals↗

PubMed1998

Virally activated Ras cooperates with integrin to induce tubulogenesis in sinusoidal endothelial cell lines.

Four cell lines, named nonparenchymal 11 (NP11), NP26, NP31, and NP32, were established from sinusoidal endothelial cells (SECs) of rat liver. They still retained expression of receptors for vascular endothelial growth factor (VEGF), Fit-1, and kinase domain-containing receptor (KDR). NP31 and NP32 turned out to be incapable of tubulogenesis in basement membrane matrix (Matrigel), which belongs to endothelial properties, as shown by SECs in primary culture. Expression of temperature-sensitive, virally activated Ras (ts-v-Ras) restored tubulogenic behaviors back to NP31 only at permissive temperature. Matrigel induced long-lasting tyrosine phosphorylation of Shc, with recruitment of Grb-2 and microtubule-associated protein kinase (MAPK) activation in both parental NP31 and NP31 transformed by ts-v-Ras, which was blocked by anti-beta1 integrin antibody. Tubulogenesis was inhibited by adenovirus-mediated expression of dominant-negative Ras in human umbilical vein endothelial cells (HUVECs). PD 098059, a selective inhibitor of MAPK kinase (MEK), nearly perfectly blocked tubulogenesis by ts-v-Ras-expressing NP31 cells at permissive temperature. Furthermore, the botulinum C3 toxin, an inhibitor for Rho, caused fragmentation of branching cords in networks formed by NP31 that expressed ts-v-Ras at permissive temperature. These data suggest that the integrin-mediated Ras signals may be necessary but are not sufficient for tubulogenesis and that an artificial expression of v-Ras might substitute for the second signal required in this system.

ADP Ribose Transferases↗

PubMed1998

Irinotecan (CPT-11) in combination with weekly administration of cisplatin (CDDP) for non-small-cell lung cancer.

PURPOSE: CPT-11 (60 mg/m2 on days 1, 8 and 15) in combination with CDDP (80 mg/m2 on day 1) has shown promising antitumor activity for non-small-cell lung cancer (NSCLC), but dose-limiting toxicities (DLT) are leukopenia and diarrhea, with a wide variation among patients. To estimate weekly CDDP administration in combination with CPT-11, a phase I study for patients with advanced NSCLC was conducted. METHODS: Patients were treated with CPT-11 at a fixed dose of 60 mg/m2 together with CDDP at 27 mg/m2 (level 1, 6 patients), 33 mg/m2 (level 2, 12 patients), and 40 mg/m2 (level 3, 6 patients) with 1600 ml hydration on days 1, 8 and 15 over 4 weeks. During the treatment course, drug was not administered on the day it was due in the presence of leukopenia (< 3000/ml) and/or diarrhea. RESULTS: The planned administration was completed in 5 of 6 patients at level 1, 6 of 12 patients at level 2, and 2 of 6 patients at level 3. The most common toxicity observed was leukopenia (five patients with grade 3 and one patient with grade 4). Leukopenia was considered to be a DLT, and the maximum tolerated dose (MTD) was level 2. Although there were patients who suffered from diarrhea (four patients with higher than grade 2), diarrhea was judged not to be a DLT with this weekly regimen. Nausea and vomiting were mild. Pharmacokinetic analysis of free platinum from CDDP demonstrated that the area under the curve (AUC) from 33 mg/m2 CDDP was 0.92 +/- 0.29 microg/ml h. In 13 patients evaluated for response, the response rate was 54%. CONCLUSION: The value of weekly administration of CDDP in combination with CPT-11 was shown by (1) diarrhea not being dose-limiting, (2) mild nausea, (3) well-maintained AUC of free platinum, and (4) promising activity.

Adult↗

PubMed1998

Interleukin-6 and development of vasospasm after subarachnoid haemorrhage.

The authors characterized the role of interleukins in the cerebrospinal fluid (CSF) in the development of vasospasm after subarachnoid haemorrhage (SAH), particularly interleukin-6 (IL-6). Concentrations of interleukin-1 beta (IL-1 beta), IL-6, and interleukin-8 (IL-8) were measured serially in CSF of 24 patients and in serum of 9 patients with SAH and correlated clinically. Additionally, the effects of the same cytokines on the cerebral arteries of dogs were analyzed on angiograms after intracisternal injection. Changes in levels of eicosanoids, angiogenic factors, and soluble cell adhesion molecules were investigated in the CSF of injected dogs. CSF concentrations of IL-6 and IL-8 were elevated significantly above control levels from the acute stage of SAH until the chronic stage. Patients with symptomatic vasospasm had significantly higher levels of IL-6 as well as IL-8 in CSF on days 5 and 7. Intracisternal injection of IL-6 induced long-lasting vasoconstriction in five out of eight dogs, while IL-8 did not. The diameter of canine basilar artery after IL-6 was reduced 29 +/- 5% from pretreatment diameter at 8 hours. Prostaglandins E2 and I2 were elevated in CSF for the first 4.5 hour of this IL-6-induced vasospasm. Neither angiogenic factors such as platelet-derived growth factor-AB and vascular endothelial growth factor nor soluble cell adhesion molecules were significantly elevated in CSF. IL-6, which increases to very high concentrations in CSF after SAH, may be important in inducing vasospasm, as IL-6 produced long-lasting vasoconstriction in the canine cerebral artery, which may be partly related to activation of the prostaglandin cascade.

Animals↗