ABSTRACT
Tumor lysis syndrome (TLS) is the rapid disintegration of a malignant tumor treated with anticancer drugs or radiation, causing electrolyte abnormalities such as elevated uric acid levels, elevated potassium and phosphorus levels, and decreased calcium levels. These abnormalities can lead to hypotension, renal dysfunction, consciousness disorders, and even death in some cases. The current patient was a 65-year-old woman who had breast cancer with local invasion, lung metastasis, and bone metastasis from the time of the initial disease onset. Despite the administration of various chemotherapy and hormone therapy regimens, the tumor increased gradually, and at 2 years and 5 months after the initial onset, pain and bleeding from metastatic infiltration of the cervical lymph nodes were noted. Therefore, radiotherapy was indicated for palliation of pain and bleeding caused by metastatic invasion of the cervical lymph nodes. Irradiation (30 Gy/10fr) was planned with a 3-field technique using 4MVX and 10MVX. Approximately 11 h after the initial irradiation, symptoms such as respiratory distress, tachycardia, and hypotension were observed. Blood tests revealed hyperuricemia and hyperkalemia, leading to a diagnosis of TLS. Dialysis and electrolyte correction were immediately initiated resulting in normalization of electrolytes and stabilization of the blood pressure. It is crucial to understand that TLS is relatively rare but can occur after radiation therapy or in solid tumors, and warrants a prompt response if suspected based on symptoms or blood findings.
ABSTRACT
We experienced a case of inflammatory carcinoma, which has been well controlled by chemotherapy, especially, vinorelbine, S-1 and trastuzumab. A 54-year-old woman was diagnosed as inflammatory carcinoma with T4d, N3c, M0 in Stage III c. The lesion was diagnosed as invasive ductal carcinoma, scirrhous, ER(-), PgR(-), HER2(3+) by core needle biopsy, The skin lesion was diagnosed as dermal lymphatic carcinomatosis by skin biopsy. The following chemotherapy was performed: FEC(5-FU 500 mg/m2, epirubicin 70 mg/m2, cyclophosphamide 500 mg/m2) followed by docetaxel(DOC 70 mg/m/2), every 3 weeks, each 6 times; after that, sequentially, vinorelbine (25 mg/m2)+trastuzumab (2 mg/kg every week), UFT(300 mg, daily)+cyclophosphamide (100 mg 2 weeks on, 1 week off)+trastuzumab (continued) and S-1 (120 mg/body 4 weeks on, 2 weeks off)+trastuzumab (continued). The patient has been well controlled by the chemotherapy with good QOL. Especially vinorelbine, S-1, and trastuzumab contributed to the disappearance of skin lesion.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Carcinoma, Ductal, Breast/drug therapy , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal, Humanized , Antimetabolites, Antineoplastic/administration & dosage , Antineoplastic Agents/administration & dosage , Antineoplastic Agents, Phytogenic/administration & dosage , Carcinoma/drug therapy , Cyclophosphamide/administration & dosage , Docetaxel , Drug Administration Schedule , Drug Combinations , Female , Humans , Inflammation , Middle Aged , Oxonic Acid/administration & dosage , Skin Neoplasms/drug therapy , Taxoids/administration & dosage , Tegafur/administration & dosage , Trastuzumab , Vinblastine/administration & dosage , Vinblastine/analogs & derivatives , VinorelbineABSTRACT
PURPOSE: Thus far, the therapy of pancreatic cancer remains an insurmountable challenge. Not a solitary therapeutic modality in the battery of available therapeutic options is capable to cure or, at the very least, stop the progression of this disease in any meaningful way. The purpose of reported here studies was to implement a multimodality approach to radioimmunotherapy of pancreatic cancer and, ultimately, to develop a course of therapy with the clinical value. EXPERIMENTAL DESIGN: Animal model was NCr-nu/nu mouse bearing s.c. xenografts of SW1990 pancreatic adenocarcinoma. Radioimmunotherapy based on (131)ICC49, a TAG-72-targeting monoclonal antibody, was augmented with imatinib, a potent inhibitor of platelet-derived growth factor receptor-beta. The postulated interactions between these two modalities depended on the imatinib-induced drop in the tumor interstitial fluid pressure and the subsequent increase of (131)ICC49 uptake into the tumor, resulting in improved tumor responses to radioimmunotherapy. RESULTS: Biodistribution studies revealed a 50% improvement in the tumor uptake of (131)ICC49 in mice treated with imatinib. Tumor development was practically arrested for approximately 3 weeks in response to the treatment composed of (131)ICC49 and imatinib with tumor quadrupling time (T(Q)) of 40.8 days. (131)ICC49 alone and imatinib alone also delayed the tumor growth to T(Q) of 30.2 and 31.2 days, respectively. Unanticipated was the significant response of SW1990 to a brief treatment with imatinib given i.p. at 100 mg/kg b.i.d. for 3 days. Xenografts in control mice receiving injection of PBS had T(Q) of 23 days. CONCLUSIONS: The inclusion of imatinib in the radioimmunotherapy regimen is beneficial and it does not produce any overt side effects. The improved responses of pancreatic cancer xenografts to the multimodality treatment comprising radioimmunotherapy and platelet-derived growth factor receptor-beta inhibition suggest that this approach to therapy of pancreatic cancer may also be successful in patients.
Subject(s)
Pancreatic Neoplasms/therapy , Radioimmunotherapy/methods , Receptor, Platelet-Derived Growth Factor beta/antagonists & inhibitors , Animals , Benzamides , Cell Line, Tumor , Female , Humans , Imatinib Mesylate , Mice , Mice, Nude , Neoplasm Transplantation , Neoplasms, Experimental , Piperazines/pharmacology , Pressure , Pyrimidines/pharmacology , Time FactorsABSTRACT
Whereas radioimmunotherapy of hematologic malignancies has evolved into a viable treatment option, the responses of solid tumors to radioimmunotherapy are discouraging. The likely cause of this problem is the interstitial hypertension inherent to all solid tumors. Remarkable improvements in tumor responses to radioimmunotherapy were discovered after the inclusion of STI571 in the therapy regimen. A combination of the tumor stroma-reactive STI571, a potent platelet-derived growth factor receptor-beta (PDGFr-beta) antagonist, and the tumor-seeking radiolabeled antibody B72.3 yielded long-lasting growth arrest of the human colorectal adenocarcinoma LS174T grown as s.c. xenografts in athymic mice. The interaction of STI571 with the stromal PDGFr-beta reduced tumor interstitial fluid pressure (P(IF)) by >50% and in so doing improved the uptake of B72.3. The attenuation of P(IF) also had a positive effect on the homogeneity of antibody distribution. These effects were dose-dependent and under optimized dosing conditions allowed for a 2.45 times increase in the tumor uptake of B72.3 as determined in the biodistribution studies. Single-photon emission computed tomography imaging studies substantiated these results and indicated that the homogeneity of the radioisotope distribution was also much improved when compared with the control mice. The increased uptake of radioimmunotherapy into the tumor resulted in >400% increase in the tumor absorbed radiation doses in STI571 + radioimmunotherapy-treated mice compared with PBS + radioimmunotherapy-treated mice. The improved antibody uptake in response to the attenuation of tumor P(IF) was identified as the primary reason for the growth arrest of the STI571 + radioimmunotherapy-treated tumors. Two related causes were also identified: (a) the improved homogeneity of monoclonal antibody distribution in tumor and (b) the increased tumor radiosensitivity resulting from the improved tumor oxygenation.
Subject(s)
Adenocarcinoma/therapy , Colorectal Neoplasms/therapy , Piperazines/pharmacology , Pyrimidines/pharmacology , Radioimmunotherapy/methods , Receptor, Platelet-Derived Growth Factor beta/antagonists & inhibitors , Adenocarcinoma/enzymology , Adenocarcinoma/metabolism , Animals , Antibodies, Monoclonal/pharmacokinetics , Antibodies, Monoclonal/pharmacology , Antibodies, Neoplasm/metabolism , Antibodies, Neoplasm/pharmacology , Antineoplastic Agents/pharmacology , Benzamides , Colorectal Neoplasms/enzymology , Colorectal Neoplasms/metabolism , Female , Humans , Imatinib Mesylate , Immunotoxins/pharmacokinetics , Immunotoxins/pharmacology , Iodine Radioisotopes/pharmacology , Mice , Mice, Nude , Protein Kinase Inhibitors/pharmacology , Swine , Tissue Distribution , Xenograft Model Antitumor Assays , Yttrium Radioisotopes/pharmacologyABSTRACT
To clarify the potential involvement of plasmin(ogen) cascade proteins in the cell dissociation and subsequent invasion of pancreatic cancer cells, western blot analysis, immunocytochemistry, immunohistochemistry, and in vitro invasion assay were performed in the cell lines or tissue of pancreatic cancer. The strong expression of plasmin(ogen), urokinase type plasminogen activator (uPA) and uPA receptor (uPAR), and apparently weak expression of the relevant proteins were found in the conditioned medium of dissociated (PC-1.0) and non-dissociated (PC-1) pancreatic cancer cells, respectively. Furthermore, uPA-treatment significantly induced the expression of plasmin(ogen) and uPAR in the conditioned medium of non-dissociated (PC-1) pancreatic cancer cells. Moreover, the expression of plasmin(ogen) and uPAR was stronger at the invasive front than at the center of human pancreatic cancer tissue. On the other hand, plasmin-treatment induced the expression of matrix metalloproteinase-2 (MMP-2), MMP-7 and MMP-9 in PC-1 cells. Simultaneously, plasmin- or uPA-treatments obviously induced the dissociation of cell colonies and in vitro invasiveness in PC-1 cells. The plasmin(ogen) cascade is closely involved in the invasion of pancreatic cancer cells and, especially in its early stage, cell dissociation. Targeting the plasmin(ogen) cascade may provide a new insight into molecular target therapy based on anti-invasion and anti-metastasis for pancreatic cancer.
Subject(s)
Adenocarcinoma/metabolism , Pancreatic Neoplasms/metabolism , Plasminogen/metabolism , Adenocarcinoma/pathology , Adult , Aged , Animals , Cell Line, Tumor , Cell Movement/drug effects , Cricetinae , Female , Fibrinolysin/pharmacology , Humans , Male , Matrix Metalloproteinase 2/biosynthesis , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 7/biosynthesis , Matrix Metalloproteinase 7/metabolism , Matrix Metalloproteinase 9/biosynthesis , Matrix Metalloproteinase 9/metabolism , Middle Aged , Neoplasm Invasiveness , Neoplasm Metastasis , Pancreatic Neoplasms/pathology , Plasminogen/biosynthesis , Receptors, Cell Surface/metabolism , Receptors, Urokinase Plasminogen Activator , Urokinase-Type Plasminogen Activator/pharmacologyABSTRACT
We report the successful conservative management of an unusual case of esophageal perforation associated with an upper thoracic spinal fracture from blunt trauma in Minamata, Kumamoto, Japan. A 69-year-old man became paraplegic secondary to an L1 burst fracture caused by a boating accident and underwent posterior fixation on the day of admission. The patient also had a minimally displaced T4 vertebral fracture. Fever, dyspnea and elevated inflammatory markers all persisted postoperatively. Computed tomography showed free mediastinal air at the T4 level, and an esophagram showed contrast medium leakage, which helped diagnose esophageal perforation. The esophageal perforation healed with conservative treatment without life-threatening complications. The possibility of esophageal injury should always be considered when treating upper thoracic spinal injuries due to blunt trauma.
ABSTRACT
Epidermal growth factor receptor (EGFR) mediated mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathway was isolated as invasion-metastasis related factor in pancreatic cancer in our previous studies. Matrix metalloproteinase-7 (MMP-7) and tight junction (TJ) proteins are indicated to be involved in cancer invasion-metastasis. To clarify the underlying mechanism of involvement of MMP-7 in cancer invasion, western blotting, invasion assay and immunohistochemistry were performed in dissociated (PC-1.0 and AsPC-1) and non-dissociated (PC-1 and Capan-2) pancreatic cancer cells, as well as pancreatic cancer tissues. Intracellular MMP-7 protein presented as pre-proenzyme and its expression was decreased by AG1478 (EGFR inhibitor) or U0126 (MEK inhibitor) treatment in pancreatic cancer cells. Activated MMP-7 protein was only detected in the medium of PC-1.0 and AsPC-1 cells, but not detected in the medium of PC-1 and Capan-2 cells. Moreover, MMP-7 treatment significant induced the dissociation of cell colonies in PC-1 and Capan-2 cells. Synchronously, TJ structure was apparently disrupted and translocation of TJ proteins to cytoplasm or extracellular medium was induced in PC-1 and Capan-2 cells. Furthermore, MMP-7 treatment markedly increased the in vitro invasion of PC-1 and Capan-2 cells. In addition, MMP-7 expression at the invasive front was obviously stronger than that at the center of pancreatic cancer tissues. Activation of MMP-7 protein is closely involved in disruption of TJ structure and consequent induction of cell dissociation as well as invasion in pancreatic cancer. EGFR mediated MEK/ERK signaling pathway is implied to be involved in regulation of MMP-7 expression in pancreatic cancer cells.
Subject(s)
Adenocarcinoma/genetics , Adenocarcinoma/pathology , Gene Expression Profiling , Matrix Metalloproteinase 7/biosynthesis , Matrix Metalloproteinase 7/metabolism , Neoplasm Invasiveness/genetics , Neoplasm Metastasis/genetics , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Animals , Blotting, Western , Cricetinae , ErbB Receptors/physiology , Humans , Immunohistochemistry , Signal Transduction , Tumor Cells, CulturedABSTRACT
Tumor responses to radioimmunotherapy combined with peptide agonists of human C5a anaphylatoxin such as GCGYSFKPMPLaR (C5aAP) are two- to four-fold better, depending on the dose of C5aAP, than responses to radioimmunotherapy alone. The enhanced tumor vascular permeability (VP) is the key factor responsible for this improvement. These studies were designed to identify the sequence of events leading to the improved extravasation of immunoglobulin in response to C5aAP. The VP changes were measured in mice after administration of C5aAP alongside of various mediators. The depletion of circulating polymorphonuclear neutrophils (PMN) in mice abolished the C5aAP-induced VP increase. Blocking of P-selectin also returned VP to its basal levels after the C5aAP treatment, indicating that C5aAP-induced VP changes are initiated by interactions of C5aAP with PMNs. Aminoguanidine, an inducible nitric oxide synthase (NOS) inhibitor, given before C5aAP returned VP to control levels. N(omega)-nitro-L-arginine methyl ester, a nonselective NOS inhibitor, had a marginal effect on the activity of C5aAP. Indomethacin, a nonselective cyclooxygenase inhibitor, suppressed C5aAP-induced increases in VP, whereas N-(2-cyclohexyloxy-4-nitrophenyl)-methanesulfonamide, a selective cyclooxygenase-2 inhibitor, was active only at high doses. While C5aAP given i.p. did not alter tumor uptake of (125)I-B72.3, the i.v. administration resulted in approximately 40% increase, confirming the prerequisite interaction of C5aAP with PMNs. The sequence leading to the increased VP appears to be initiated by the interaction of C5aAP with C5a receptor expressed on PMNs followed by binding to endothelial cells of blood vessels. The interaction with P-selectin is responsible for the initiation of the nitric oxide cascade as evidenced by inducible NOS activation. Additionally, prostaglandins are required for expression of the full magnitude of the C5aAP activities.
Subject(s)
Capillary Permeability/drug effects , Complement C5a/pharmacology , Neutrophils/physiology , Nitric Oxide Synthase/metabolism , Prostaglandin-Endoperoxide Synthases/metabolism , Animals , Antibodies, Monoclonal/pharmacology , Binding, Competitive , CHO Cells , Cell Line, Tumor , Complement C5a/chemistry , Complement C5a/metabolism , Cricetinae , Cricetulus , Cyclooxygenase Inhibitors/pharmacology , Enzyme Inhibitors/pharmacology , Female , Granulocytes/immunology , Guanidines/pharmacology , Humans , Indomethacin/pharmacology , Mice , Mice, Nude , NG-Nitroarginine Methyl Ester/pharmacology , Nitric Oxide Synthase/antagonists & inhibitors , Nitrobenzenes/pharmacology , Oligopeptides/chemical synthesis , Oligopeptides/metabolism , Oligopeptides/pharmacology , P-Selectin/immunology , Protein Binding , Receptor, Anaphylatoxin C5a/metabolism , Sulfonamides/pharmacology , Xenograft Model Antitumor AssaysABSTRACT
BACKGROUND: Human liver has an unusual sensitivity to radiation that limits its use in cancer therapy or in preconditioning for hepatocyte transplantation. Because the characteristic veno-occlusive lesions of radiation-induced liver disease do not occur in rodents, there has been no experimental model to investigate the limits of safe radiation therapy or explore the pathogenesis of hepatic veno-occlusive disease. METHODS AND MATERIALS: We performed a dose-escalation study in a primate, the cynomolgus monkey, using hypofractionated stereotactic body radiotherapy in 13 animals. RESULTS: At doses ≥40 Gy, animals developed a systemic syndrome resembling human radiation-induced liver disease, consisting of decreased albumin, elevated alkaline phosphatase, loss of appetite, ascites, and normal bilirubin. Higher radiation doses were lethal, causing severe disease that required euthanasia approximately 10 weeks after radiation. Even at lower doses in which radiation-induced liver disease was mild or nonexistent, latent and significant injury to hepatocytes was demonstrated by asialoglycoprotein-mediated functional imaging. These monkeys developed hepatic failure with encephalopathy when they received parenteral nutrition containing high concentrations of glucose. Histologically, livers showed central obstruction via an unusual intimal swelling that progressed to central fibrosis. CONCLUSIONS: The cynomolgus monkey, as the first animal model of human veno-occlusive radiation-induced liver disease, provides a resource for characterizing the early changes and pathogenesis of venocclusion, for establishing nonlethal therapeutic dosages, and for examining experimental therapies to minimize radiation injury.
Subject(s)
Disease Models, Animal , Hepatic Veno-Occlusive Disease/etiology , Hepatocytes/radiation effects , Liver/radiation effects , Macaca fascicularis , Radiation Injuries, Experimental/etiology , Alanine Transaminase/analysis , Albumins/analysis , Alkaline Phosphatase/analysis , Animals , Body Weight/radiation effects , Dose Fractionation, Radiation , Hepatic Veno-Occlusive Disease/diagnostic imaging , Hepatic Veno-Occlusive Disease/pathology , Hepatocytes/diagnostic imaging , Hepatocytes/pathology , Liver/diagnostic imaging , Liver/pathology , Liver/surgery , Liver Failure, Acute/etiology , Male , Radiation Dosage , Radiation Injuries, Experimental/diagnostic imaging , Radiation Injuries, Experimental/pathology , Radiosurgery/adverse effects , Retreatment , Tomography, Emission-Computed, Single-Photon/methodsABSTRACT
Pancreatic cancer does not respond to a single-agent imatinib therapy. Consequently, multimodality treatments are contemplated. Published data indicate that in colorectal cancer, imatinib and radioimmunotherapy synergize to delay tumor growth. In pancreatic cancer, the tumor response is additive. This disparity of outcomes merited further studies because interactions between these modalities depend on the imatinib-induced reduction of the tumor interstitial fluid pressure. The examination of human and murine PDGFr-ß/PDGF-B pathways in SW1990 pancreatic cancer xenografts revealed that the human branch is practically dormant in untreated tumors but the insult on the stromal component produces massive responses of human cancer cells. Inhibition of the stromal PDGFr-ß with imatinib activates human PDGFr-ß/PDGF-B signaling loop, silent in untreated xenografts, via an apparent paracrine rescue pathway. Responses are treatment- and time-dependent. Soon after treatment, levels of human PDGFr-ß, compared to untreated tumors, are 3.4×, 12.4×, and 5.7× higher in imatinib-, radioimmunotherapy + imatinib-, and radioimmunotherapy-treated tumors, respectively. A continuous 14-day irradiation of imatinib-treated xenografts reduces levels of PDGFr-ß and phosphorylated PDGFr-ß by 5.3× and 4×, compared to earlier times. Human PDGF-B is upregulated suggesting that the survival signaling via the autocrine pathway is also triggered after stromal injury. These findings indicate that therapies targeting pancreatic cancer stromal components may have unintended mitogenic effects and that these effects can be reversed when imatinib is used in conjunction with radioimmunotherapy.
ABSTRACT
Claudin-1 is a tight junction transmembrane protein. Its localization in the maturation ameloblasts of rat incisors was examined by immunofluorescence microscopy. Distal junction area of ruffle-ended ameloblasts (RA) and the Golgi apparatus of a sub-population of smooth-ended ameloblasts (SA) and RAs stained positive with anti-claudin-1 antibodies. Since it has been shown that ameloblasts repeatedly alternate between an SA and an RA morphology during enamel maturation, the presence of claudin-1 in the Golgi cisterns may indicate the presence of tight junction precursors before transportation to the junctional area.
ABSTRACT
The clinical application of radioimmunotherapy (RIT) as a single modality in the treatment of prostate cancer is held back because of poor tumor responses to RIT and unacceptable normal tissue toxicities. The purpose of reported here studies was to develop a multimodality approach to RIT of prostate cancer that includes imatinib, a potent PDGFRbeta inhibitor, and in the course of these studies to define the mechanism of imatinib effects on RIT. Hypothesized interactions between these two modalities depend on the reduction of tumor interstitial fluid pressure with the subsequent increase of (131)ICC49 uptake into the tumor, and the inhibition of HIF-1alpha resulting in the improved tumor radiosensitivity. Levels of HIF-1alpha, IGF-1, PDGF-BB, phospho-PDGFRbeta and VEGF in response to imatinib were examined in PC-3 human prostate adenocarcinoma cells in vitro and in xenografts. RIT was based on (131)ICC49 and it was augmented with imatinib. Although PDGFRbeta appears to be functional in PC-3 tumors, the effect of imatinib on the tumor interstitial fluid pressure was insignificant. PC-3 cells and PC-3 xenografts express constitutive HIF-1alpha, which was significantly inhibited by imatinib. Reduced levels of HIF-1alpha were accompanied by the notable suppression of IGF-1. Simultaneously the increase in tumor levels of mouse and human PDGF-BB was observed. Improved PC-3 responses to RIT+imatinib treatment were significant and lasted approximately two weeks. Tumor doubling times in mice treated with (131)ICC49+imatinib were 21.6 +/- 0.7 days compared to 17.2 +/- 0.5 days in (131)ICC49+PBS-treated control mice. Imatinib alone had no effect on the tumor growth. In conclusion, imatinib inhibits HIF-1alpha expression in PC-3 tumors and improves RIT, but it has no effect on VEGF indicating absence of anti-angiogenic effects. There is a significant time- and dose-dependent reduction in the expression of IGF-1 suggesting an alternative pathway of imatinib-regulated HIF-1alpha expression leading to the improved PC-3 responses to RIT.
Subject(s)
Antineoplastic Agents/pharmacology , Hypoxia-Inducible Factor 1, alpha Subunit/antagonists & inhibitors , Piperazines/therapeutic use , Prostatic Neoplasms/therapy , Pyrimidines/therapeutic use , Radioimmunotherapy , Receptor, Platelet-Derived Growth Factor beta/antagonists & inhibitors , Animals , Becaplermin , Benzamides , Cell Line, Tumor , Dose-Response Relationship, Drug , Hypoxia-Inducible Factor 1, alpha Subunit/analysis , Imatinib Mesylate , Insulin-Like Growth Factor I/analysis , Male , Mice , Mice, Nude , Platelet-Derived Growth Factor/analysis , Prostatic Neoplasms/pathology , Proto-Oncogene Proteins c-sis , Receptor, Platelet-Derived Growth Factor beta/analysisABSTRACT
BACKGROUND & AIMS: Management of patients with liver failure can be a significant medical challenge, and transplantation of the liver is the only definitive therapy. Whole liver allotransplantation is limited by a shortage of human donors and the risks of the surgery in those most ill. Transplants consisting of xenogeneic hepatocytes might overcome these problems, and work in rodents indicates that such transplants can correct some metabolic deficiencies and can prevent the complications and mortality associated with hepatic failure. As a prelude to clinical application, we tested the feasibility of hepatocyte xenotransplantation in nonhuman primates. METHODS: One to 2 billion hepatocytes from outbred swine were transplanted into the spleens of cynomolgus monkeys using conventional immunosuppression to control rejection. Duration of graft function was determined based on assay for porcine albumin. RESULTS: Following a single infusion, xenogeneic hepatocytes functioned for more than 80 days and, following re-transplantation, for more than 253 days. Engraftment in the spleen was confirmed 40 days after transplantation by asialoglycoprotein receptor-directed nuclear scanning. The humoral immune response to the transplanted porcine cells had no discernible impact on the survival of the grafts. CONCLUSIONS: Xenotransplantation of hepatocytes should be explored as a readily available, minimally invasive form of therapy for hepatic failure.
Subject(s)
Graft Survival , Hepatocytes/transplantation , Transplantation, Heterologous/methods , Animals , Animals, Outbred Strains , Antibodies, Heterophile/blood , Asialoglycoprotein Receptor/metabolism , Cell Transplantation/methods , Feasibility Studies , Hepatocytes/immunology , Hepatocytes/physiology , Immunosuppressive Agents/pharmacology , Macaca fascicularis , Male , Radionuclide Imaging , Serum Albumin , Spleen/diagnostic imaging , Swine , TechnetiumABSTRACT
The micromeres, the first cells to be specified in sea urchin embryos, are generated by unequal cleavage at the fourth cell division. The micromeres differentiate autonomously to form spicules and dispatch signals to induce endomesoderm in the neighbouring macromeres cells in the embryo. Using a calcium indicator Fura-2/AM and a mixture of dextran conjugated Oregon green-BAPTA 488 and Rhodamine red, the intracellular calcium ion concentration ([Ca2+]i) was studied in embryos at the 16-cell stage. [Ca2+]i was characteristically elevated in the micromeres during furrowing at the 4th cleavage. Subsequently, Ca2+ oscillated for about 10 min in the micromeres, resulting in episodic high levels of [Ca2+]i. High [Ca2+]i regions were associated with regional localizations of the endoplasmic reticulum (ER), though not with ER accumulated at the vegetal pole of the micromeres during the 4th division. Pharmacological studies, using a blocker of IP3-mediated Ca2+ release (Xestospongin), a store-operated Ca2+ entry inhibitor (2 aminoethoxydiphenyl borate (2-APB)) and an inhibitor of stretch-dependent ion channels (gadolinium), suggest that the high [Ca2+]i and oscillations in the micromeres are triggered by calcium influx caused by the activation of stretch-dependent calcium channels, followed by the release of calcium ions from the endoplasmic reticulum. On the basis of these new findings, a possible mechanism for autonomous formation of the micromeres is discussed.
Subject(s)
Calcium Signaling , Calcium/metabolism , Embryo, Nonmammalian/cytology , Embryo, Nonmammalian/metabolism , Sea Urchins/embryology , Sea Urchins/metabolism , Animals , Boron Compounds/pharmacology , Calcium Signaling/drug effects , Embryo, Nonmammalian/drug effects , Endoplasmic Reticulum/drug effects , Endoplasmic Reticulum/metabolism , Gadolinium/pharmacology , Imidazoles/pharmacology , Inositol 1,4,5-Trisphosphate/metabolism , Macrocyclic Compounds , Microtubules/drug effects , Microtubules/metabolism , Oxazoles/pharmacology , Sea Urchins/cytology , Sea Urchins/drug effectsABSTRACT
Transplantation of isolated hepatocytes may eventually replace a whole liver transplantation for the treatment of selected liver metabolic disorders and acute hepatic failure. To understand the behavior of transplanted hepatocytes, methods for longitudinal assessment of functional activity and survival of hepatocyte transplants must be developed. Targeting of asialoglycoprotein receptor (ASGPr) with various radiolabeled or Gd-labeled constructs of asialofetuin (AF) is expected to allow noninvasive and quantitative assessments of the ASGPr status in functioning hepatocytes before and after the transplant. Six new constructs of (125)I-, (99m)Tc-, (153)Gd-, and (111)In-radiolabeled AF with distinct stabilities and clearance rates were prepared and evaluated in vitro in mice, rat, porcine, and human hepatocytes, and in vivo in mice and rats. The blood and organ clearance rates, as well as liver and spleen uptake, were measured. Even extensive chemical modifications of AF with poly-l-lysine and various chelating agents do not appear to diminish AF's binding to ASGPr. Binding to isolated hepatocytes and the in vivo liver uptake studies indicate unimpaired functional activity of AF as evidenced by the rapid (<10 min) and nearly complete hepatic extraction of AF constructs from the systemic circulation. The catabolic processing and elimination of AF constructs from liver depend on the chemical modification used in the preparation of a given reagent. Radioiodinated AF has by far the shortest postabsorption (5.1 min +/- 0.05 min) and elimination half-lives (2.8 +/- 0.06 h) in liver. In comparison, the AF construct prepared by conjugation of DTPA- and 2-iminothiolane-substituted p-Lys with N-sulfosuccinimidyl 4-(p-maleimidophenyl)butyrate (SMPB)-modified AF (AF-SMPB-Traut-p-Lys-((111)In-DTPA)(20)(-)(30)) has a hepatic postabsorption time of 9.1 +/- 0.1 min and an elimination half-life of 44.3 +/- 3.08 h, whereas [(99m)Tc]technetium-labeled AF appears to be permanently retained in liver. These differences in rates of liver uptake and clearance of catabolized radiolabeled AF can be used to determine functional activity of liver and transplanted hepatocytes.