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PubMed1989

Stab wounds of the renal artery branches: angiographic diagnosis and treatment by embolization.

Renal artery branch injury resulting from stab wounds of iatrogenic origin or street violence is an important cause of renal hemorrhage. Over a period of 10 years we accurately diagnosed the injury and successfully managed the associated hemorrhage in 15 patients by using angiography and percutaneous embolization techniques. Nine branch injuries in eight patients were due to street knifings and seven injuries were complications of invasive medical procedures (four from renal biopsy, two from nephrostolithotomy, and one from nephrostomy). All patients had gross hematuria at the time of angiographic evaluation. False aneurysms were present in six patients (one with associated frank extravasation), false aneurysm/arteriovenous fistula in three, false aneurysm/arteriocaliceal fistula in one, and isolated arteriovenous fistula in two. Frank extravasation without associated false aneurysm/arteriovenous fistula was present in two. One patient had two injuries, an upper-pole false aneurysm and a lower-pole false aneurysm/arteriovenous fistula. In the eight patients injured in street knifings, hematuria recurred after surgical exploration and treatment. None of the 16 injuries involved the main renal artery. Gelfoam was used for embolization of nine lesions and steel coils for four. Three others were treated with Gelfoam plus coils. Hemostasis was achieved in all and none required subsequent surgery. Renal tissue loss was small to moderate (less than 30%) in 12 patients and large (30-50%) in three patients. Transient postembolization hypertension occurred in one of the latter. We consider selective angiography/embolization to be an effective and safe means for diagnosing and treating wounds of the renal artery branches.

Adolescent↗
PubMed1991

Recurrent hepatocellular carcinoma after partial hepatectomy: value of treatment with transcatheter arterial chemoembolization.

The usefulness of transcatheter arterial chemoembolization (TACE) of the hepatic artery was retrospectively evaluated in 66 patients who underwent the procedure for treatment of hepatocellular carcinoma that recurred after partial hepatectomy. The materials infused were Gelfoam sponge or Gelfoam sponge plus Lipiodol and an anticancer agent. A control group of 15 patients with recurrent tumor received oral anticancer agents alone. The cumulative survival rate for the TACE group was 88% for the first year, 57% for 2 years, 42% for 3 years, and 27% for 5 years, whereas that of the control group was 80% for the first year, 27% for 2 years, and 18% for 3 years. Thus, the prognosis of the TACE group was significantly better (p less than or equal to .01, log-rank test) than that of the control group. The survival rate was inversely correlated with the ratio of the volume of the recurrent tumor to the volume of the whole residual liver. These results suggest that TACE is more effective than oral chemotherapy for treatment of hepatocellular carcinoma that recurs after partial hepatectomy.

Antineoplastic Agents↗
PubMed2002

Cochlear delivery of fibroblast growth factor 1 and its effects on apoptosis and cell cycling in noise-exposed guinea pig ears.

OBJECTIVES: Acidic fibroblast growth factor 1 (FGF-1) is a mitogen and antiapoptotic factor synthesized by cochlear neurons and transported to the organ of Corti. The objectives of this investigation were threefold: (1) to develop an animal model to study the cochlear effects of intratympanic delivery of FGF-1; (2) to determine the distribution, in the mature mammalian cochlea, of FGF-1 and the receptor, FGFR3, to which it binds with high affinity; and (3) to examine the effect of exogenous FGF-1 on cochlear apoptotic and cell-cycling markers in noise and non-noise-exposed guinea pigs ears. METHODS: Fifteen adult Hartley guinea pigs were divided into three groups. Group 1 animals (n = 5) underwent direct placement of FGF-1 in phosphate buffered saline (PBS) (20 pg/mL) soaked Gelfoam pledgets to the right round window membrane. Phosphate buffered saline-soaked Gelfoam pledgets were placed on the left round window membrane as a control. In group 2 animals (n = 5), surgical placement of either FGF-1 or PBS was followed by exposure to 120 dB of white noise for 2 hours. Group 3 animals (n = 5) were subjected to identical noise conditions prior to undergoing round window application of either FGF-1 or PBS. All groups were allowed to recover in a noise-controlled environment for 12 hours following surgery. Anti-FGF-1-stained Western blots and optical densitometry analyses were used to quantitate passage of FGF-1 into cochlear perilymph. Standard in situ immunohistochemical techniques were used to stain each cochlea for FGF-1 and FGFR3, apoptotic markers p53 and p21, Bcl-2, and the cell-cycling marker proliferating cell nuclear antigen (PCNA). Tissue sections were subjected to the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labelling technique (TUNEL) for apoptosis. RESULTS: Western blot and optical densitometry analyses of cochlear perilymph showed increased concentrations of FGF-1 in 10 of 14 experimental cochleas. Cochlear perilymph FGF-1 was consistently bound to heparan sulphate proteoglycan (HSPG). Immunoreactivity of both FGF-1 and FGFR3 was observed in spiral ganglion neurons, inner and outer hair cells, pillar cells, and Dieter and Hensen's cells. Specific FGF-1 immunostaining to the distal portion of the pars pectinata of the basilar membrane was noted in noise-exposed animals only. Bcl-2 and PCNA immunostaining was not detected in any group. There was no significant nuclear immunoreactivity to proapoptotic markers, p53 and p21, in any group. Semiquantitative analysis of TUNEL staining in block sections of all cochleas demonstrated a 340% increase in nuclear immunoreactivity of noise-exposed outer hair cells and organ of Corti cells. There was no difference between FGF-1 treated and control ears subjected to TUNEL staining. CONCLUSIONS: Exogenous FGF-1 crosses the round window membrane and is bound to HSPG in cochlear perilymph. The specific immunoreactivity of the pars pectinata to FGF-1 may represent a unique reservoir for cochlear FGF-1 in noise-exposed ears of the guinea pig. Noise induces apoptosis of organ of Corti cells as demonstrated with the TUNEL technique. PCNA, Bcl-2, p53, and p21 in noise-exposed and non-noise-exposed guinea pig cochleas are not affected by exogenous FGF-1. Noise-induced hair cell apoptosis appears to be independent of the p53 pathway. Lack of immunoreactivity to Bcl-2 supports the concept that the apoptotic mechanism is likely to involve C-Jun-N-terminal kinase- or caspase-dependent pathways. Exogenous FGF-1 does not alter apoptosis or cell cycling in the mature guinea pig cochlea within 12 hours of acute acoustic trauma.

Animals↗
PubMed2000

Surgical treatment of spontaneous spinal cerebrospinal fluid leaks.

Spontaneous spinal cerebrospinal fluid (CSF) leaks are an increasingly recognized cause of intracranial hypotension. In this report the authors review the indications for surgery, surgical techniques, and surgery-related outcomes for these lesions. The major presenting symptoms include postural headaches, nausea, vomiting, and diplopia. Often, there is no history of traumatic injury. The most common cranial magnetic resonance (MR) imaging features include pachymeningeal gadolinium enhancement and sagging of the brain. On spinal MR images, diverticula are frequently noted. In cases in which symptoms are severe and refractory to less invasive measures, surgical intervention is indicated. Tears in the dura or leaking diverticula that are identified as the sources of the CSF leak often can be ligated or repaired. When a source of CSF egress is not found intraoperatively, packing the epidural space with blood-soaked Gelfoam or muscle at the appropriate level can lead to relief of symptoms. Occasionally the dural defect is large, irregular, or has attenuated borders that may not be possible to repair with sutures. These may be repaired by packing the defect with muscle or blood-soaked Gelfoam. Indications for and outcomes of surgery in patients with this condition will become more defined as surgeons gain experience with these procedures.

Cerebrospinal Fluid Pressure↗
PubMed1990

Secretion of alpha 2-macroglobulin, alpha 2-antiplasmin, and plasminogen activator inhibitor-1 by glioblastoma multiforme in primary organ culture.

Explants from a glioblastoma multiforme were maintained for 4 weeks in a three-dimensional Gelfoam matrix culture in order to study the synthesis of alpha 2-antiplasmin (alpha 2AP), alpha 2-macroglobulin (alpha 2M), plasminogen activator inhibitor-1 (PAI-1), and tissue plasminogen activator (t-PA). Since the organ culture system promotes cellular differentiation in gliomas with increasing time in vitro, secretion of the proteinase inhibitors and t-PA was examined at weekly intervals. Increased immunohistochemical staining for glial fibrillary acidic protein, a marker of astroglial differentiation, was observed in the explants with advancing time in culture. The proteinase inhibitors alpha 2AP and alpha 2M were secreted into the medium in all 4 weeks, while PAI-1 was detected at significant concentrations by an enzyme-linked immunosorbent assay (ELISA) in Weeks 3 and 4 only. The quantity of each inhibitor secreted into fresh medium during a 24-hour interval increased with the age of the tumor explants in the Gelfoam culture system. At no time was a sensitive ELISA able to detect t-PA in the culture medium. This study demonstrates that glioblastoma multiforme cells in primary organ culture can secrete three major fibrinolysis proteinase inhibitors. The appearance of PAI-1 only after extensive culturing of the explants suggests a possible correlation with neoplastic astroglial maturation.

Brain Neoplasms↗
PubMed2002

Uterine arterial embolization for the treatment of uterine leiomyomas.

OBJECTIVE: The purpose of this study was to establish guidelines for using uterine artery embolization for the treatment of uterine leiomyomas accompanied by adenomyosis in Korea. This study was performed to investigate 1) the effects of uterine embolization on leiomyoma accompanied by adenomyosis, 2) the outcome of uterine embolization according to the embolization materials used, 3) the relationship between the Resistance Index (RI) and the change in uterine volume. MATERIALS AND METHODS: We performed a retrospective study on 37 women who had uterine leiomyomas accompanied by adenomyosis. Bilateral uterine artery embolization was performed over a period of 17 months in 37 patients (age range 25 - 65) experiencing pain, hypermenorrhea, urinary frequency, etc. due to leiomyomas. Ultrasound imaging was performed before the procedure and at mean 6.9 months after the procedure. RESULTS: All procedures were technically successful. Mean clinical follow-up time was 12.8 months. Minor complications occurred in 82% patients following the procedure. After follow-up imaging, the median uterine volume decreased by 34.4% and the dominant myoma volume decreased by 86%. There was no statistical difference in the uterine volume reduction and the dominant myoma size reduction, whether the occluding agent was polyvinyl alcohol, polyvinyl alcohol plus gelfoam, or gelfoam, and whether the ultrasound measured Resistance Index value before the procedure was low or high. CONCLUSION: Primary candidates for uterine artery embolization include those with symptomatic uterine leiomyomas, who no longer desire fertility, but who wish to avoid surgery or are poor surgical risks. According to the results of our study, adenomyosis should not be considered as a contraindication for uterine artery embolization. However, because little data is available about the subsequent reproductive potential following this procedure, it should not be routinely advocated for infertile women. Further investigation is warranted regarding the choice of occluding agent and the role of the Resistance Index.

Adult↗
PubMed1999

Glial cell line-derived neurotrophic factor rescues target-deprived sympathetic spinal cord neurons but requires transforming growth factor-beta as cofactor in vivo.

Glial cell line-derived neurotrophic factor (GDNF) is a potent neurotrophic factor for several populations of CNS and peripheral neurons. Synthesis and storage of GDNF by the neuron-like adrenal medullary cells suggest roles in adrenal functions and/or in the maintenance of spinal cord neurons that innervate the adrenal medulla. We show that unilateral adrenomedullectomy causes degeneration of all sympathetic preganglionic neurons within the intermediolateral column (IML) of spinal cord segments T7-T10 that project to the adrenal medulla. In situ hybridization revealed that IML neurons express the glycosylphosphatidylinositol-linked alpha receptor 1 and c-Ret receptors, which are essential for GDNF signaling. IML neurons also display immunoreactivity for transforming growth factor-beta (TGF-beta) receptor II. Administration of GDNF (recombinant human, 1 microg) in Gelfoam implanted into the medullectomized adrenal gland rescued all Fluoro-Gold-labeled preganglionic neurons projecting to the adrenal medulla after four weeks. Cytochrome c applied as a control protein was not effective. The protective effect of GDNF was prevented by co-administration to the Gelfoam of neutralizing antibodies recognizing all three TGF-beta isoforms but not GDNF. This suggests that the presence of endogenous TGF-beta was essential for permitting a neurotrophic effect of GDNF. Our data indicate that GDNF has a capacity to protect a population of autonomic spinal cord neurons from target-deprived cell death. Furthermore, our results demonstrate for the first time that the previously reported requirement of TGF-beta for permitting trophic actions of GDNF in vitro (Kreiglstein et al., 1998) also applies to the in vivo situation.

Adrenal Glands↗
PubMedDate not supplied

Experimental and clinical studies on liver regeneration following transcatheter portal embolization.

BACKGROUND/AIMS: We studied compensatory hypertrophy following transcatheter portal embolization experimentally in dogs and clinically under the condition of cholestasis. METHODOLOGY: Experimental study: Sixteen dogs were used for this study. Transcatheter portal embolization was performed in the left lobes (70% of the total liver) using Gelfoam powder in dogs with 2-week obstructive jaundice. Liver weight, liver blood flow and the intracellular adenosine triphosphate content of isolated hepatocytes were measured after transcatheter portal embolization. Clinical Study: transcatheter portal embolization of the right portal branch was performed in 13 patients with cancer of the biliary tract and 3 patients with hepatocellular carcinoma before (extended) right lobectomy, using Gelfoam powder and thrombin. Six patients who had a total bilirubin level > 5 mg/dLunderwent a percutaneous transhepatic biliary drainage before transcatheter portal embolization. Liver function tests, a volumetric study with computed tomography and immunohistochemical staining for profilerating cell nuclear antigen and apoptosis in the resected livers were performed. RESULTS: Experimental study: The weight ratio of the non-embolized lobes to the total liver, 2 weeks after transcatheter portal embolization in the dogs with jaundice, was significantly lower than that of the normal dogs with transcatheter portal embolization (40.5 +/- 4.5% vs. 47.6 +/- 3.2%), but significantly larger than that of the dogs without transcatheter portal embolization. The cellular adenosine triphosphate content and tissue blood flow in the embolized lobes were significantly lower than those in the nonembolized lobes in the normal and cholestatic livers. Clinical study: The postoperative course in all patients was uneventful, with no serious complication or liver dysfunction. Extended right lobectomy with caudate lobectomy was equivalent to 65% before transcatheter portal embolization and to 56% after, transcatheter portal embolization owing to compensatory hypertrophy of the left lobe. However, there was no significant difference in liver volume in the patients with or without obstructive jaundice. Apoptosis was observed in the embolized lobe. CONCLUSIONS: Preoperative transcatheter portal embolization with percutaneous transhepatic biliary drainage for the purpose of liver regeneration would be useful for treating extended hepatectomy with obstructive jaundice.

Animals↗
PubMed2000

Percutaneous obliteration of duodenal fistula.

High output external duodenal fistula is a difficult condition to treat and despite the advances in nutritional care, morbidity and mortality remain high. Although, non surgical methods (e.g. endoscopy, fistuloscopy and percutaneous injection of substances) have been reported sporadically in the treatment of enterocutaneous fistulae, gelfoam has not been tried. We present a case of duodenal fistula following blunt abdominal trauma which persisted for 14 weeks on conservative management. Percutaneous obliteration of the duodenal fistula was successfully performed using gelfoam injection through a catheter. This procedure is simple, safe and cheap and further experience may demonstrate that it is an easy and more practical tool in dealing with this problem.

Abdominal Injuries↗
PubMed1998

Bletilla striata as a vascular embolizing agent in interventional treatment of primary hepatic carcinoma.

OBJECTIVE: To evaluate Bletilla striata as a vascular embolizing agent in interventional treatment of primary hepatic carcinoma. METHODS: We made a vascular embolizing agent from a Chinese medicinal herb, Bletilla striata (bai ji). From October 1991 to January 1995, 56 patients with primary hepatic carcinoma were treated by hepatic arterial chemoembolization with Bletilla striata angioembolus, and 50 patients with primary hepatic carcinoma who were treated by conventional gelfoam embolization served as controls. All patients were followed up for 10-48 months. RESULTS: Embolization with the Bletilla striata powder produced extensive and permanent vascular obstruction, resulting in marked shrinkage of the tumor and significant decrease of serum alpha fetoprotein (AFP) level. After embolization, less collateral circulation formed later. The treatment interval was prolonged to an average of 7 months. The 1-, 2- and 3-year survival rates were 81.9%, 44.9%, and 33.6%, respectively, with a mean survival period of 19.8 months. All the clinical parameters were better than those in the control group treated by conventional gelfoam embolization. CONCLUSION: Bletilla striata angioembolus is a good vascular embolizing agent for treating PHC.

Adult↗
PubMed1975

Experimental diminution fo splenci function by selective embolization of the splenic artery.

The splenic artery was occluded by the selective injection of Amicar-mixed clot or Gelfoam in 18 dogs. The dogs were sacrificed at 24 hours, two weeks and two months. Angiography was done before and after embolization, three hours after embolization and prior to sacrifice. White blood counts and hematocrit values were evaluated weekly in the dogs sacrificed at two months. The results of this study reveal differences in the effects of the two embolic materials. Because Amicar-mixed clot was partially lysed in the first several hours and also pushed peripherally, the depression of hematologic function seen with its use was transient and most spleens returned to a relatively normal gross and histologic appearance. With Gelfoam, although the embolic material was also pushed peripherally into the branches of the splenic artery in several of the dogs, the depression of hematologic function was prolonged, and moderate splenic parenchymal fibrosis was seen. The areas between the bands of fibrosis appeared normal. The results indicate that selective embolic occlusion of the splenic artery and its branches may offer a method of depressing splenic function in patients who are not candidates for splenectomy.

Aminocaproates↗
PubMed1975

Dendrites and neuroglia following hemisection of rat spinal cord: effects of puromycin.

Within 60 to 90 days of spinal cord hemisection or hemisection, Gelfoam, water implantation in the lesion site, ventral horn neurons 0 to 5 mm proximal to the site of lesion form varicosities along the dendrite. The varicosities form on peripheral dendrites at 10 days and progressively involve the entire dendritic shaft by 60 to 90 days. Following spinal cord hemisection and Gelfoam puromycin implantation the neurons in the ventral horn are resistant to varicosity formation. Sixty days after hemisection puromycin-treated neurons form a few varicosities on occasional peripheral dendrites with no further involvement of the dendrite by 90 days postlesion. The neuroglial reaction to hemisection is not altered by puromycin treatment. The correlation of inhibition of protein synthesis and resistance to dendritic varicosity formation is discussed.

Animals↗
PubMed2001

Hepatic artery angiography and embolization for hemobilia after hepatobiliary surgery.

OBJECTIVE: To evaluate the effectiveness of hepatic angiography and embolization in the diagnosis and treatment of hemobilia after hepatobiliary surgery. METHODS: Nine patients had upper gastrointestinal bleeding 7 days to 3 months after surgery. They underwent emergency hepatic artery angiography and were treated by embolization using Gelfoam particles only (8 patients) and Gelfoam particles plus microcoils (1 patient). RESULTS: Hepatic artery angiography revealed hepatic artery pseudoaneurysms in 3 patients, diffuse hemorrhage of the hepatic artery branches in 3, right hepatic artery-bile duct fistulas in 2, and hepatic artery-small intestine fistula in 1. Hemobilia was controlled with embolization in 7 patients, of whom 1 had recurrent bleeding 1 day after treatment. During the follow-up, 3 patients died of multiple organ dysfunction syndrome. Two patients whose hemorrhage could not be controlled due to technical reasons died several days later. CONCLUSION: When hemobilia after hepatobiliary surgery is suspected, patients should receive hepatic angiography as a first diagnostic procedure and be treated with minimally invasive procedure of selective embolization of the involved artery as soon as possible.

Adolescent↗
PubMed2002

Mechanical stretch regimen enhances the formation of bioengineered autologous cardiac muscle grafts.

BACKGROUND: Surgical repair of congenital and acquired cardiac defects may be enhanced by the use of autologous bioengineered muscle grafts. These tissue-engineered constructs are not optimal in their formation and function. We hypothesized that a mechanical stretch regimen applied to human heart cells that were seeded on a three-dimensional gelatin scaffold (Gelfoam) would improve tissue formation and enhance graft strength. METHODS AND RESULTS: Heart cells from children undergoing repair of Tetralogy of Fallot were isolated and cultured. Heart cells were seeded on gelatin-matrix scaffolds (Gelfoam) and subjected to cyclical mechanical stress (n=7) using the Bio-Stretch Apparatus (80 cycles/minute for 14 days). Control scaffolds (n=7) were maintained under identical conditions but without cyclical stretch. Cell counting, histology, and computerized image analysis determined cell proliferation and their spatial distribution within the tissue-engineered grafts. Collagen matrix formation and organization was determined with polarized light and laser confocal microscopy. Uniaxial tensile testing assessed tissue-engineered graft function. Human heart cells proliferated within the gelatin scaffold. Remarkably, grafts that were subjected to cyclical stretch demonstrated increased cell proliferation and a marked improvement of cell distribution. Collagen matrix formation and organization was enhanced by mechanical stretch. Both maximal tensile strength and resistance to stretch were improved by cyclical mechanical stretch. CONCLUSION: The cyclical mechanical stretch regimen enhanced the formation of a three-dimensional tissue-engineered cardiac graft by improving the proliferation and distribution of seeded human heart cells and by stimulating organized matrix formation resulting in an order of magnitude increase in the mechanical strength of the graft.

Absorbable Implants↗
PubMed2000

[The preoperative application of selective catheterization and embolism of the external carotid artery in treating tumors with enriched blood supply in the base of skull].

OBJECTIVE: Embolizing the feeding vessels of the tumors with enriched blood supply in the base of skull in order to reduce the bleeding during operation. METHOD: Under digital subtraction angiographic control, superselectively catheterizing the external carotid artery, thus occluding the terminal branches of the feeding arteries of the tumor with particles of liquidized gelfoam. RESULT: Nine cases studied showed that the angiography of the feeding vessels of the tumor disappeared relatively. The bleeding decreased significantly during operation. The postoperative pathological findings showed that the entity of the tumor was congested with gelfoam. CONCLUSION: After figuring out the blood supply of the tumor, superselective catheterization of the external carotid artery followed by occlusion of the feeding vessels can reduce the size of the tumor and diminish the bleeding during operation, thus can improve the safety of the operation. It should be one of the crucial preoperation measures.

Adolescent↗
PubMed1992

The effect of transforming growth factor-alpha on airway angiogenesis.

A problem in lung transplantation is tracheal or bronchial dehiscence from ischemia. To determine if an angiogenic factor applied to the airway would improve capillary regrowth, a three-ring segment of trachea was completely severed and sutured in rats. In one group of animals the ischemic segment was wrapped with Gelfoam soaked in an angiogenic factor, transforming growth factor-alpha. In a second group the ischemic area was wrapped with Gelfoam soaked with only the vehicle. In a third group the devascularized area received no additional treatment. One animal from each group was killed daily for 7 days after operation. The tracheal vasculature was cast and viewed by light and scanning electron microscopy. None of the four animals that died early were in the transforming growth factor-alpha group. All animals lost weight between the day of operation and death, but this was least in the transforming growth factor-alpha group (p = 0.05). The light microscopy showed ischemic changes and the development of granulation tissue. The scanning electron microscopy of the vascular casts showed extensive loss of the vessels in the cut area. On day 1 the vessels of all animals dilated and their walls became rough. By day 3 a few corkscrew vessels penetrated the ischemic zone. By day 4 the animal that received transforming growth factor-alpha had more capillaries than the others. By day 6 revascularization in the transforming growth factor-alpha animal was abundant. Besides budding, new capillaries appeared to develop by lateral growth. After the fifth day vessels about 30 to 50 microns in diameter bulged focally. On the bulges, ridges the size, shape, and pattern of capillaries formed. Capillary formation in this manner has not been reported previously. Revascularization emerged sooner and more extensively with transforming growth factor-alpha. No adverse effect of transforming growth factor-alpha was found.

Animals↗
PubMed2003

Angiopoietin-1 inhibits vascular permeability, angiogenesis, and growth of hepatic colon cancer tumors.

Angiopoietin (Ang)-1 and -2 are critical regulators of embryonic and postnatal neovascularization. Ang-1 activates the endothelial cell-specific tyrosine kinase receptor Tie-2, which in turn leads to enhanced endothelial cell survival and stabilization. The effects of Ang-1 on tumor angiogenesis remain controversial; although we have previously demonstrated that Ang-1 overexpression in colon cancer cells leads to a decrease in s.c. tumor growth, others have shown that Ang-1 may be proangiogenic. Few studies have addressed the role of the Angs in tumors growing in the organ of metastatic growth. We hypothesized that overexpression of Ang-1 may inhibit the growth of colon cancers growing in the liver by inhibition of angiogenesis. We also wanted to investigate the mechanisms by which Ang-1 affects angiogenesis in vivo. Human colon cancer cells (HT29) were stably transfected with an Ang-1 construct or an empty vector (pcDNA) and injected directly into the livers of nude mice. After 37 days, livers were harvested and weighed, and tumor sizes were measured. In an additional experiment, to validate the paracrine effect of Ang-1, various mixtures of control cells and Ang-1-transfected cells were injected into livers, and tumor growth was assessed. Direct effects of recombinant Ang-1 on angiogenesis were studied with an in vivo Gelfoam angiogenesis assay. The impact of Ang-1 on vascular permeability was investigated using an intradermal Miles assay with conditioned media from transfected cells. Liver weights (P < 0.05), tumor volumes (P < 0.05), vessel counts (P < 0.01), and tumor cell proliferation (P < 0.01) in the Ang-1 group were significantly lower than those in the control (pcDNA) group. Tumor vessels in the Ang-1 group developed a significantly higher degree of pericyte coverage (P < 0.02) than vessels in pcDNA tumors. In the cell mixture experiment, even as few as a 1:10 mixture of Ang-1-transfected cells/control cells resulted in a significant reduction of hepatic tumor volumes (P < 0.04). In the angiogenesis assay, vessel counts in Gelfoam implants were significantly decreased by the addition of Ang-1 (P < 0.01). Finally, conditioned medium from Ang-1-transfected cells decreased vascular permeability more than that from control cells (P < 0.05). Our results suggest that Ang-1 is an important regulator of angiogenesis and vascular permeability and that this effect may be secondary to increasing periendothelial support and vessel stabilization. Thus, Ang-1 could potentially serve as an antineoplastic or anti-permeability agent for patients with metastatic colorectal cancer.

Angiogenesis Inducing Agents↗
PubMed1992

[Preoperative embolization for meningiomas using PVA particles].

Preoperative embolization for highly vascularized and large meningiomas is an indispensable technique for facilitating their surgical removal by decreasing blood loss during the operation. This is a report of 4 large and highly vascularized meningiomas in the skull base, on which embolization of feeders was performed preoperatively by PVA (Polyvinyl alcohol foam) particles (150-250 micron produced by INGENOR CO, Paris) and small strips of gelfoam (0.5 x 0.5 x 3-5mm). Under EEG monitoring, Isosorbide dinitrate was used for prevention and relief of vascular spasm. Lidocaine injection tests (Xylocaine 2%: 50mg mixed in equal volumes with Iopamiron 300) were performed for checking before embolization. In the intracranial portion, standard taper steerable guide wire was changed to seeker flexible soft-tip guide wire. In two cases, the meningioma was located in the medial part of the sphenoidal ridge. In the other two cases, one meningioma was in the lateral part of the sphenoidal ridge and the other was in the olfactory groove. In all 4 cases, we successfully performed embolization without complication. In one case, we had to perform embolization twice, because of revascularization detected by angiography 3 weeks after the first embolization. In this latter case, we had performed central embolization only, by using PVA particles, having left feeder without occlusion (peripheral embolization) using gelfoam. The result suggested that it was also necessary to perform peripheral embolization especially if the tumor is fed by large tortuous and irregular abnormal vessels. Peripheral embolization may prevent PVA particles from washing out and causing progressive thrombosis by PVA particles.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗