Preparation of glial extracellular matrix: a novel method to analyze glial-endothelial cell interaction

Studies on the interactions of endothelial cells and glial cells are of increasing importance for the understanding of the formation of the blood-brain barrier (BBB) and for the reconstruction of BBB properties in cultured brain capillary endothelial cells in vitro. Many methods have been used to examine cell-cell interactions, including conditioned medium, co-culture, feeder layers, and many others. Here we describe how to prepare the extracellular matrix (ECM) secreted from cultured cells. Cells are known to produce and interact with their extracellular components in an organized matrix and to regulate the function of other cells through the ECM. The ECM plays a central role in the differentiation and function of the cells, and controls the proliferation and motility of these cells. The responses of cells to ECM molecules need to be clarified. As the ECM is situated between cerebral capillaries and astrocytes in the central nervous system, the ECM secreted by glial cells may also play an important role in the formation and maintenance of the BBB. In our previous studies, the ECM produced by glial cells elevated gamma-glutamyl transpeptidase activity, which is an accepted marker enzyme for differentiated brain capillary endothelial cells, in cultured bovine brain capillary and aortic endothelial cells. Using the method described here, the cell-cell interaction via the ECM molecules can be examined.

Distal pancreatectomy with en bloc resection of the celiac artery for carcinoma of the body and tail of the pancreas

CONCLUSION

Combined resection of the celiac artery with a distal pancreatectomy (DP) increases the resectability and improves the overall prognosis of patients with locally advanced ductal cancer of the body and tail of the pancreas.

BACKGROUND

Carcinoma of the body and tail of the pancreas is often unresectable because of invasion to adjacent organs. We evaluated a DP including an en bloc resection of the celiac artery ("extended"), for pancreatic cancer that had invaded the common hepatic and/or celiac arteries.

METHODS

Six cases of an "extended" DP were compared with 19 cases of a "standard" DP for pancreatic ductal carcinoma in terms of clinical and pathologic findings, perioperative course, and long-term outcome. We also compared the survival rate of these two groups with a third group consisting of 22 patients with unresectable pancreatic ductal carcinoma.

RESULTS

The mean operative time, postoperative serum aspartate aminotransferase concentration, and length of hospital stay did not significantly differ between the "extended" and "standard" DP groups. The cumulative 1- and 3-yr accumulated survival rates for the "extended," "standard," and unresectable groups were 40.0, 33.3, and 5.4, and 20.0, 16.6, and 0%, respectively. Statistically significant differences (p < 0.01) existed between the "extended" and unresected groups.

Antimetastatic effect of synthetic Glu-Ile-Leu-Asp-Val peptide derivatives containing D-amino acids

The aim of this study was to increase the antimetastatic potency of the fibronectin-related peptide, Glu-Ile-Leu-Asp-Val (EILDV), and to determine the minimal core sequence of EILDV required to inhibit tumor metastasis in vivo. The EILDV subpeptide analog, ILDV, markedly inhibited the adhesion of B16-BL6 melanoma cells to fibronectin. EILD and ILD were only slightly inhibitory, and the smaller overlapping tripeptide, LDV, was inactive. The inhibitory activities of ILDV and LDV on the migration of B16-BL6 melanoma cells were as potent as those of EILDV, whereas ILD did not inhibit cell migration. These results suggested that the minimal sequences essential for cell adhesion and migration are ILD and LDV, respectively. However, the antimetastatic effects of all subpeptide analogs were lower than that of EILDV. In order to improve the stability in vivo, we synthesized various EILDV-related peptides substituted with a D-amino acid. EILDV containing D-Glu or D-Ile inhibited cell adhesion and migration as potent as EILDV, whereas replacing Leu, Asp or Val with the corresponding D-isomer reduced the antiadhesive activities. The inhibitory effect of EILDV-related peptides containing D-Leu, D-Asp or D-Val on migration was also lower than that of EILDV. All synthetic EILDV-related peptides containing D-amino acids inhibited metastasis by B16-BL6 melanoma cells to the same extent as EILDV, whereas the specific activity of EILDV was decreased by the D-amino acid substitution. These results indicated that the balance of stability in vivo and biological activity in vitro is important in inhibiting tumor metastasis.

Antibody-based therapy targeting tumor vascular endothelial cells suppresses solid tumor growth in rats

We have developed a new approach to antibody-based therapy of solid tumors by targeting tumor vascular endothelial cells (EC) which are essential for the growth of solid tumors. We investigated the effect of an antibody against tumor-derived endothelial cells (TEC) on the growth of solid tumors in rats. Intravenous administration of TES-23, a monoclonal antibody generated by TEC isolated from rat KMT-17 solid tumors, at 1 mg/rat/day for 5 days resulted in significant suppression of KMT-17 tumor growth. Histopathological analysis of tumors administered with TES-23 showed that adhesion of lymphocytes to EC followed by denudation of EC in the viable tumor area. In contrast, little obvious toxicity was observed in most of the rat organs examined. These findings suggest that the concept of an antibody-based therapy with targeting tumor vascular EC would be promising in treatment of solid tumors.

Enhancing effect of nonionic surfactant on the inactivation of lipopolysaccharide by steam-heat treatment II

n-alkylpolyoxyethylene surfactants (CnH2n+1O(CH2CH2O)mH; CnEm) showed a strong enhancing effect on the inactivation of lipopolysaccharide (LPS) by heat treatment over a wide range of temperatures. The effect of CnE8 (n = 10-16) was observed above the critical micelle concentration (CMC) and above the cloud point, and was influenced by the length of the alkyl chains. The efficacy of the surfactants was in the order C10E8 < C12E8, C16E8 < C14E8. However, the hydrophilic moiety seemed to have no influence. An 80-95% solution of n-butanol showed a similar effect, indicating that LPS was more effectively inactivated in the oily phase of the surfactants than in water. The effect of surfactant on the hydrodynamic diameter of LPS was the same before and after steam-heat treatment for 20 minutes at 121 degrees C. Each surfactant disaggregated LPS without alteration of the activity of LPS before the heat treatment. We consider that the surfactants interact with LPS in the region of lipid A in a manner that favors loss of the activities of LPS during heating.

A novel type of calcium channel sensitive to omega-agatoxin-TK in cultured rat cerebral cortical neurons

We characterized the electrophysiological properties of calcium channels in cultured rat cerebral cortical neurons using omega-agatoxin-TK (omega-Aga-TK) by a patch-clamp technique. Two types of slowly inactivating calcium channels sensitive to omega-Aga-TK were detected. The first type showed high sensitivity to omega-Aga-TK and low recovery from the omega-Aga-TK-induced blockade during washout, corresponding to the P-type channel. The second type showed low sensitivity to omega-Aga-TK and high recovery, resembling the Q-type channel, although it was distinct from the Q-type in terms of slower inactivation kinetics. We designate this channel as Q(L)-type (long-lasting Q channel). The omega-Aga-TK-sensitive calcium channels involved in the glutamatergic synaptic transmission were also divided into two types based on the sensitivity to omega-Aga-TK and reversibility of omega-Aga-TK-induced blockade. We conclude that the Q(L)-type is a novel type of channel, and that both P-type and Q(L)-type channels play a significant role in the cerebral cortical synaptic transmission.

Cytoplasmic gene expression system enhances the efficiency of cationic liposome-mediated in vivo gene transfer into mouse brain

Development of methodologies for gene transfer into the central nervous system (CNS) is important for fundamental research as well as clinical studies for gene therapy. Cationic liposomes (CL) are attractive vectors because of their safety and ease of use. However, to date only low rates of success have been reported. We succeeded in obtaining high transfection efficiencies into the newborn mouse brain in vivo by CL and a cytoplasmic gene expression system based on T7 RNA polymerase and T7 RNA polymerase- and the luciferase-gene with the T7 promoter sequence. This system showed an efficiency rate 2 orders of magnitude higher than the standard system, which used CL and luciferase genes with a Rous sarcoma virus promoter, pRSVL. In addition, in vitro experiments using LLCMK2 cells showed that cytoplasmic gene expression occurred rapidly (within 6 h) after transfection. In contrast, pRSVL required 24-48 h for induction of luciferase expression. Our results suggest that the cytoplasmic gene expression system is useful for gene delivery into the CNS.

Bruceine B, a potent inhibitor of leukocyte-endothelial cell adhesion

Leukocyte adhesion to vascular endothelial cells is an essential step in the development of inflammatory diseases. We have searched for inhibitors of leukocyte-endothelial cell adhesion that could be used as anti-inflammatory drugs and found that bruceine B (0.2 microgram/ml; 0.44 microM) inhibited human neutrophil or T cell adhesion to tumor necrosis factor-alpha (TNF) stimulated human umbilical vein endothelial cells (HUVEC). The inhibition of neutrophil adhesion to TNF-stimulated HUVEC by bruceine B was not derived from cytotoxic effects, as determined by measurement of the level of lactate dehydrogenase (LDH) activity in conditioned medium. The effect of bruceine B on neutrophil adhesion to HUVEC was not seen when the neutrophils were preincubated with bruceine B. However, inhibitory effects were evident when the HUVEC were preincubated with bruceine B. Bruceine B also inhibited neutrophil adhesion to lipopolysaccharide-stimulated HUVEC and T cell adhesion to TNF-stimulated HUVEC. These findings suggest that bruceine B may have anti-inflammatory activity.

Therapeutic effect of cytomedicine on mesangio-proliferative glomerulonephritis in human interleukin-6 transgenic mice

We previously demonstrated that IgG1 plasmacytosis in human interleukin-6 transgenic mice (hIL-6 Tgm) was suppressed by the implantation of SK2 hybridoma cells (SK2 cells, which secrete anti-hIL-6 monoclonal antibodies) microencapsulated in a semipermeable and biocompatible device. In this study, we demonstrated that the mesangio-proliferative glomerulonephritis in hIL-6 Tgm was also improved by the same treatment. These results strongly support the concept of cytomedicine, which is a novel drug delivery system (DDS) using living cells. However, an electron microscopy study showed that cytomedicine has a limited duration of effectiveness because of the disappearance of space for cell proliferation in the microcapsule. Thus, the control of cell proliferation in a device must be developed to prolong the function and effectiveness of cytomedicine.

Cytomedical therapy for IgG1 plasmacytosis in human interleukin-6 transgenic mice using hybridoma cells microencapsulated in alginate-poly(L)lysine-alginate membrane

Cytomedical therapy for human interleukin-6 transgenic mice (hIL-6 Tgm) was implemented by the intraperitoneal injection of alginate-poly(L)lysine-alginate (APA) membranes microencapsulating SK2 hybridoma cells (APA-SK2 cells) which secrete anti-hIL-6 monoclonal antibodies (SK2 mAb). IgG1 plasmacytosis in the hIL-6 Tgm was suppressed by a single injection of APA-SK2 cells, and the survival time of these mice was remarkably prolonged. The viable cell number and the SK2 mAb-secretion of APA-SK2 cells increased for at least one month both under culture conditions and in allogeneic recipients (in vivo). Moreover, SK2 mAb which were secreted from APA-SK2 cells injected into allogeneic recipients was detected in serum at high concentrations; 3-5 mg/ml from day 14 to day 50 post-injection. In contrast, the injection of free SK2 cells had no therapeutic effect on hIL-6 Tgm. These results strongly suggest that APA membranes microencapsulating cells which were modified to secrete molecules useful for the treatment of a disorder were effective as an in vivo long-term delivery system of bioactive molecules, as 'cytomedicine'.

Immunological studies of SK2 hybridoma cells microencapsulated with alginate-poly(L)lysine-alginate (APA) membrane following allogeneic transplantation

Microencapsulation of living cells or tissues has been proposed to prevent their immune destruction following transplantation. In this study, we examined whether SK2 hybridoma cells microencapsulated in an alginate-poly(L)lysine-alginate (APA) membrane (APA-SK2 cells) were immunoisolated from the allogeneic host's immune system using a cytotoxicity test. The APA membrane inhibited the activation of the host's cellular immune response, but did not prevent the production of cytotoxic antibodies against entrapped SK2 cells following allogeneic transplantation. However, the APA-SK2 cells remained vital in SK2 cell-immunized mice as well as in intact mice. We considered that complement regulatory factors which were present on cell membrane and had species-specific restriction blocked the complement-mediated cell lysis on allogeneic transplantation, since APA-SK2 cells were destroyed by rabbit anti-SK2 cell antiserum. Our results demonstrated that APA membrane could inhibit cell-cell contact between entrapped cells and the host's lymphocytes, but could not completely protect the entrapped cells from xenogeneic humoral immunity.

PEGylation of interleukin-6 effectively increases its thrombopoietic potency

The in vivo thrombopoietic activity of polyethylene glycol-modified interleukin-6 (MPEG-IL-6), in which 54% of the 14 lysine amino groups of IL-6 were coupled with PEG, was compared to that of native IL-6. Native IL-6 and MPEG-IL-6, which showed about 51% of the specific bioactivity of native IL-6, were administered subcutaneously to mice every 2 days for 7 days. Native IL-6 increased not only the peripheral platelet count, but also the plasma-IgG1 level in a dose-dependent manner. MPEG-IL-6 showed about 500 times higher thrombopoietic potency than native IL-6. Further, in comparison to native IL-6, MPEG-IL-6 did not enhance IgG1 production as much as it enhanced platelet production. MPEG-IL-6 significantly stimulated platelet recovery in mice treated with 5-fluorouracil, whereas the administration of native IL-6 had a negligible effect. The plasma half-life of MPEG-IL-6 was about 100-fold longer than that of native IL-6. The decrease in the plasma clearance of MPEG-IL-6 was thought to be due, in part, to the shielding of the proteolytic sites in the IL-6 molecule by the PEG chain. The uptake of IL-6 by the reticuloendothelial system, such as the liver and spleen, was markedly limited by PEGylation. The PEGylation of IL-6 markedly enhanced the blood-residency of IL-6, resulting in effective augmentation of its thrombopoietic activity and a marked decrease in its side-effects. These findings suggest that MPEG-IL-6 may be a potential candidate for thrombopoietic agent.

Lecithinization of IL-6 enhances its thrombopoietic activity in mice

This study was conducted to assess the merit of lecithinization of recombinant human interleukin-6 (IL-6) as a drug delivery system. IL-6 was lecithinized by covalently binding it with a phosphatidylcholine (lecithin, PC) derivative. The in-vivo thrombopoietic potency of lecithinized IL-6 (PC-IL-6) was greater than that of native IL-6 when administered subcutaneously, although the in-vitro bioactivity of PC-IL-6 was markedly reduced by lecithinization. When PC-IL-6 and native IL-6 were given in doses that produced the same level of thrombopoietic activity, the former stimulated less production of IgG1, a marker of the adverse effects of IL-6, than did the latter. Furthermore, PC-IL-6 persisted in the blood longer than native IL-6. Based on the above, PC-IL-6 appears to be useful as a drug delivery system and may also be useful in the treatment of drug-induced thrombocytopenia.

Comparison of tympanic, esophageal and blood temperatures during mild hypothermic cardiopulmonary bypass: a study using an infrared emission detection tympanic thermometer

OBJECTIVE

Tympanic temperature can be obtained instantaneously using an infrared emission detection (IRED) thermometer. Its accuracy has been documented in a variety of clinical settings, but its performance at low body temperatures is still unknown. In this study we evaluated its performance during coronary artery revascularization surgery in which mild hypothermic cardiopulmonary bypass (CPB) was used.

METHODS

Thirty adult patients undergoing coronary artery bypass graft surgery were enrolled in the study. Tympanic temperature obtained using IRED thermometry (Tt1) was compared with core temperatures from the esophagus (Te), and venous blood of CPB (Tv) before, during, and after CPB. We also measured tympanic temperature using a thermocouple probe (Tt2) in 16 of the 30 patients in order to study the agreement between the two methods. Values for correlation coefficients and limits of agreement were computed to assess the degree of agreement among the temperatures obtained.

RESULTS

The highest agreement with Tv during CPB was obtained from Tt1 (r = 0.94, 0.41 +/- 1.73, limits of agreement) and from Te (0.91, 0.36 +/- 2.46). Tt1 also showed good agreement with Tt2 during surgery.

CONCLUSIONS

Infrared tympanic thermometry is a reliable, alternative method to measure tympanic temperature and may be useful to assess core temperature in both normothermic and mild hypothermic conditions.

Preparation of influenza virosome vaccine with muramyldipeptide derivative B30-MDP

An influenza virosome vaccine, consisting of influenza hemagglutinin-neuraminidase antigens (HANA), the muramyldipeptide derivative 6-O-(2-tetra-decylhexadecanoyl)-N-acetyl-muramyl-L-alanyl-D-isoglu tamine (B30-MDP) and cholesterol, was prepared by the detergent removal method using a flow-through dialyzer, Liposomat. The shape of the influenza virosome vaccine mimicked that of the influenza virus, namely, B30-MDP/cholesterol vesicle covered with HANA spikes. THe particle size and size distribution of prepared virosomes were evaluated by quasi-elastic laser light scattering and gel permeation chromatography. The state of incorporation of HANA spikes at the membrane surface of virosome was confirmed by electron microscopy. The results indicated that virosome formation was influenced by initial B30-MDP concentration in the mixed micellar solution prior to dialysis. It is apparent that the initial concentration of B30-MDP, relative to the mixed-micelle-to-virosome transition, is an important factor for virosome preparation. Accordingly, the transition was evaluated and clarified by the changes in membrane fluidity and particle size during the dialysis process. The results indicated that it is important to adjust the initial B30-MDP concentration in the mixed micellar solution before dialysis so that the concentration for the mixed-micelle-to-vesicle transition coincides with that for mixed-micelle-to-rosette-transition appropriate for virosome formation.

Amino acids and peptides. XXIX. Synthesis and antimetastatic effects of peptides and peptide-poly(ethylene glycol) hybrids related to the core sequence of the type III connecting segment domain of fibronectin

Peptides (H-Glu-Ile-Leu-Asp-Val-NH2, H-Glu-Ile-Leu-Asp-Val-Pro-Ser-Thr-NH2, H-Arg-Glu-Asp-Val-NH2) and their poly(ethylene glycol) (PEG) hybrids related to the core sequence of the type III connecting segment domain of fibronectin A chain were prepared by the solution method or the solid phase method. Their inhibitory effects on the adhesion and migration of B16-BL6 melanoma cells to fibronectin were assessed in vitro, and their therapeutic potency against tumor metastasis were also examined. Anti-adhesive and anti-migrative effects of the synthetic fibronectin-related peptids were superior to those of their PEG hybrids, so we found that the in vitro bioactivity of peptides decreased by PEGylation. In the in vivo assay, we found that the synthetic peptides containing Glu-Ile-Leu-Asp-Val and Arg-Glu-Asp-Val sequences exhibited an inhibitory effect on the experimental metastasis of B16-BL6 melanoma. Of the synthetic peptides, H-Glu-Ile-Leu-Asp-Val-NH2 exhibited the most potent inhibitory effect. Hybrid formation of Arg-Glu-Asp-Val with poly(ethylene glycol) resulted in potentiation of the inhibitory effect of the parent peptides. A mixture composed of PEG hybrids of Glu-Ile-Leu-Asp-Val, Arg-Glu-Asp-Val and Tyr-Ile-Gly-Ser-Arg dramatically inhibited tumor metastasis.

Indonesian medicinal plants. XVII. Characterization of quassinoids from the stems of Quassia indica

Four new quassinoids named samaderines X (1), Y (2) and Z (3), and indaquassin X (5), and a new C19 quassinoid glycoside, 2-O-glucosylsamaderine C (10), together with five known quassinoids, samaderines B (7), C (8), and E (4), indaquassin C (6), and simarinolide (9), were isolated form the stems of Quassia indica (Simaroubaceae), an Indonesian medicinal plant. The chemical structures of these quassinoids have been elucidated on the bases of their chemical and physiochemical properties. Samaderines X (1), Z (3), E (4), and B (7) were shown to exhibit significant growth-inhibitory activity against the cultured malarial parasite Plasmodium falciparum (a chloroquine- resistant K1 strain), and 1--8 were shown to exhibit in vitro cytotoxicity (IC50: 0.04--100 micrograms/ml) against KB cells. Samaderines X (1), B (7) and C (8), as well s indaquassin X (5), exhibited inhibitory activity in the in vitro endothelial cell-neutrophil leukocyte adhesion assay, whereas samaderines X (1) and B (7) were found to exhibit significant anti-inflammatory activity.

In vivo anti-tumor efficacy of polyethylene glycol-modified tumor necrosis factor-alpha against tumor necrosis factor-resistant tumors

We previously reported that the optimally PEGylated tumor necrosis factor-alpha (MPEG-TNF-alpha), in which 56% of the TNF-alpha-lysine amino groups were coupled with polyethylene glycol (PEG), had about 100-fold greater anti-tumor effect than native TNF-alpha. Here, we assessed the usefulness of MPEG-TNF-alpha as a systemic anti-tumor therapeutic drug, using B16-BL6 melanoma and colon-26 adenocarcinoma, which have been reported to be resistant to TNF-alpha in vivo, as compared with Meth-A fibrosarcoma. MPEG-TNF-alpha markedly inhibited the growth of both tumors without causing any TNF-alpha-mediated side-effects, whereas native TNF-alpha had no anti-tumor effects and caused adverse side-effects. In addition, MPEG-TNF-alpha drastically inhibited the metastatic colony formation of B16-BL6 melanoma. MPEG-TNF-alpha may, thus, be a potential systemic anti-tumor therapeutic agent.

Molecular design of hybrid tumour necrosis factor-alpha. II: The molecular size of polyethylene glycol-modified tumour necrosis factor-alpha affects its anti-tumour potency

To design hybrid tumour necrosis factor-alpha (TNF-alpha) applicable to systemic anti-tumour therapeutic use, we assessed the relationships among the molecular size of hybrid TNF-alpha, in vitro bioactivity and in vivo anti-tumour potency. Natural human TNF-alpha was covalently modified with polyethylene glycol (PEG) of various number-average molecular weights (Mn = 2000, 5000, 12,000). The in vitro bioactivity of PEG-modified TNF-alpha s decreased with an increase in the degree of PEG modification, irrespective of the molecular weight of PEG. This decrease in the specific bioactivity markedly increased with an increase in the molecular weight of the attached PEG. The in vivo anti-tumour effects of the hybrid TNF-alpha s with a molecular size from 100 to 110 kDa, which had more than 50% of specific bioactivity of native TNF-alpha, were significantly superior to other PEG-TNF-alpha s. These hybrid TNF-alpha s showed over ten times greater anti-tumour effects than native TNF-alpha. Thus, the molecular size, which was determined by the degree of PEG modification and PEG molecular weight, influences the specific activity and anti-tumour effects of hybrid TNF-alpha.

Molecular design of hybrid tumor necrosis factor-alpha III: polyethylene glycol-modified tumor necrosis factor-alpha has markedly enhanced antitumor potency due to longer plasma half-life and higher tumor accumulation

We have reported that chemical modification of tumor necrosis factor-alpha (TNF-alpha) with polyethylene glycol (PEG) markedly increases its antitumor potency without any adverse side effects. MPEG-TNF-alpha, especially, in which 56% of the lysine amino groups of TNF-alpha are coupled with PEG, exhibits 100-fold more antitumor activity in vivo than native TNF-alpha in the Meth-A murine sarcoma model. In this study, we investigated the pharmacokinetics of PEG-modified TNF-alpha with various molecular sizes to clarify the mechanisms of the enhanced antitumor potency of MPEG-TNF-alpha. The plasma half-lives of modified TNF-alpha increased with increasing molecular size. The decreased plasma clearance of modified TNF-alpha was partially caused by the shielding effect of the proteolytic sites in TNF-alpha by the attached PEG and the decreased transport from blood to various tissues. Almost all native TNF-alpha was uniformly distributed to the kidney and reticuloendothelial system within 1 hr of an intravenous administration, and rapidly disappeared from these tissues at 3 hr. However, very little native TNF-alpha was transported into the tumor. The absolute distributed amount and distribution profile of modified TNF-alpha to tissues other than the tumor were the same as those of native TNF-alpha, whereas the plasma levels of the modified TNF-alpha were higher than plasma levels of the native TNF-alpha. The tumor distribution of modified TNF-alpha was markedly enhanced compared with native TNF-alpha and gradually increased over time. About 9-fold more MPEG-TNF-alpha was distributed to the tumor than native TNF-alpha. Thus, we found that the marked increase in the antitumor potency of PEG-modified TNF-alpha resulted from the enhanced blood residency and tumor accumulation. The antitumor effect of MPEG-TNF-alpha against sarcoma-180 other than Meth-A fibrosarcoma was also about 100 times greater than that of native TNF-alpha when systemically administered. The optimal PEGylation of TNF-alpha facilitated its antitumor potency and MPEG-TNF-alpha may be useful systemic antitumor therapeutic drug.

Evaluation of angiogenic inhibitors with an in vivo quantitative angiogenesis method using agarose microencapsulation and mouse hemoglobin enzyme-linked immunosorbent assay

In the present work, using a previously reported in vivo quantitative tumor-angiogenesis model, we attempted to ascertain whether this animal model is suitable for practical use in monitoring inhibitors of tumor angiogenesis. Mouse sarcoma-180 cells, human A431 cells or rat C6 cells microencapsulated in agarose beads were implanted s.c. into C57BL/6 mice. The level of blood vessel induction at the agarose pellet site was evaluated using mouse hemoglobin enzyme-linked immunosorbent assay on day 10 after implantation. Hydrocortisone, tetrahydro-S, medroxyprogesterone acetate, pentosan polysulfate and suramin inhibited blood vessel growth in our in vivo tumor-angiogenesis assay system, and heparin enhanced the antiangiogenic effects of hydrocortisone and tetrahydro-S. These results are almost entirely consistent with those observed in common assay systems, and suggest that this method may be useful for the identification and quantitative evaluation of inhibitors of tumor angiogenesis.

Selective enhancement by tumor necrosis factor-alpha of vascular permeability of new blood vessels induced with agarose hydrogel-entrapped Meth-A fibrosarcoma cells

We have previously developed a simple and quantitative method for assessment of in vivo tumor cell-induced angiogenesis by means of microencapsulation of tumor cells in agarose hydrogel and mouse hemoglobin ELISA (mHb-ELISA). In this article, we report that the new blood vessels induced with agarose-encapsulated tumor cells have the same sensitivity to tumor necrosis factor-alpha (TNF-alpha) as the original solid-tumor vessels. Agarose beads (average diameter = 200 microns), in which Meth-A fibrosarcoma cells were microencapsulated, were subcutaneously implanted in non-syngeneic ddY mice. Ten days later, extensive angiogenesis was observed on the implanted sites of Meth-A agarose heads, whereas no new blood vessels were induced with cell-free agarose heads. The vascular permeability of the new blood vessels induced with agarose-microencapsulated Meth-A cells was selectively and significantly enhanced by the i.v. injection of TNF-alpha, and it reached the maximum level at 2 h after the injection of TNF-alpha. At 4 h after the injection of TNF-alpha, the vascular permeability was reduced to the basal level. This permeability profile in Meth-A agarose beads in ddY mice is very similar to that in Meth-A solid tumor in syngeneic BALB/c mice. On the other hand, TNF-alpha-treatment did not affect the vascular permeability of other normal tissues or inflammatory tissue in ddY mice. These results strongly suggest that the new blood vessels induced with agarose-microencapsulated tumor cells have the specific characteristics of tumor vessels. Our in vivo angiogenesis assay system should be useful not only to screen anti-angiogenetic agents, but also to elucidate the mechanism of tumor angiogenesis.

Zonal heterogeneity of hepatic injury following shock/resuscitation: relationship of xanthine oxidase activity to localization of neutrophil accumulation and central lobular necrosis

Post-ischemic hepatic injury is characterized by zonal heterogeneity of injury (central lobular necrosis), sinusoidal neutrophil accumulation, and injury generated by reactive oxygen metabolites. We evaluated the role of the heterogeneous distribution of hepatic xanthine oxidase in the generation of neutrophil accumulation and consequent hepatocellular injury in rats subjected to shock [controlled hemorrhagic hypotension (mean arterial pressure = 37.5 + or - 2.5 mmHg for 120 min)], with or without subsequent resuscitation and hemodynamic stabilization, compared with sham-operated rats. Shock/resuscitation produced striking neutrophil accumulation (assayed by esterase histochemistry) in the pericentral sinusoids, associated with centrolobular necrosis. This paralleled the pericentral distribution of xanthine oxidase (determined by histochemical assay of frozen sections) and its release from the liver into the circulation at resuscitation. Pretreatment with allopurinol inhibited hepatic xanthine oxidase activity, neutrophil accumulation, and pericentral hepatocyte necrosis in shock/resuscitation in rats. These findings suggest that reactive oxygen metabolites generated by heterogeneously distributed xanthine oxidase may contribute to the heterogeneity of hepatocellular injury in "ischemic hepatitis."

Marine natural products. XXXVI. Biologically active polyacetylenes, adociacetylenes A, B, C, and D, from an Okinawan Marine sponge of Adocia sp

Adociacetylenes A (1), B (2), C (3), and D (4) were isolated as new polyacetylenes from an Okinawan marine sponge of Adocia sp. Their chemical structures have been elucidated on the bases of their chemical and physicochemical properties. Adociacetylenes A (1), C (3), and D (4) exhibited inhibitory activity in the in vitro endothelial cell-neutrophil leukocyte adhesion assay.