Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 21
Filter
Add more filters










Publication year range
2.
Angiología ; 59(5): 387-391, sept.-oct. 2007. ilus
Article in Es | IBECS | ID: ibc-056510

ABSTRACT

Introducción. El aneurisma de aorta torácica complicado con una fístula aortobronquial es una entidad poco común que, sin control de su evolución, posee baja supervivencia debido a la hemoptisis masiva. La cirugía convencional se asocia a una alta tasa de mortalidad perioperatoria. Actualmente, el tratamiento endovascular ofrece una solución menos invasiva para esta patología. Presentamos un caso clínico y realizamos una revisión bibliográfica de esta entidad infrecuente, así como de los métodos de diagnóstico y las alternativas terapéuticas. Caso clínico. Varón de 67 años con hemoptisis masiva y descompensación hemodinámica a causa de una fístula aortobronquial por aneurisma verdadero de la aorta torácica de 6,7 cm diagnosticado por tomografía computarizada (TC), angiorresonancia y angiografía. El paciente fue sometido a un tratamiento endovascular con endoprótesis autoexpandible de politetrafluoroetileno (TAG Excluder 40 × 200 mm), previa colocación de urgencia de un balón oclusor aórtico, hasta lograr la compensación hemodinámica. No se registraron episodios de hemoptisis en el seguimiento. Los estudios fibrobroncoscópicos en el período postoperatorio fueron negativos. La TC de tórax de control mostró la exclusión completa del aneurisma. Conclusión. El tratamiento endovascular es una alternativa terapéutica segura para la resolución de un aneurisma verdadero de la aorta torácica complicado con una fístula aortobronquial


Introduction. Aneurysm of the thoracic aorta complicated with acute haemoptysis due to aortobronchial fistula is a lifethreating uncommon pathology. Open surgery is associated to a high perioperative mortality rate. Actually, endovascular approach offers a less invasive solution for this problem. We present a case report, and perform a bibliographic review of this unusual disease, as well a diagnostic images methods and current therapy modalities. Case report. A 67 years old male patient with a history of massive haemoptysis and unstable hemodynamically due to aortobronchial fistula secondary to a 6.7 cm thoracic aorta aneurysm, diagnosed by CT scan, angioresonance, and angiography. The patient was treated successfully by endovascular approach with a PTFE endograft (TAG Excluder 40 × 200 mm) being previously treated with an aortic occlusion balloon catheter. There were no episodes of haemoptysis in the postoperative period, and the fibrobronchoscopy was normal. CT scan showed total aneurysm exclusion. Conclusion. Endovascular approach is a safe alternative treatment when dealing with complicated thoracic aorta aneurysm due to aortobronchial fistula


Subject(s)
Male , Middle Aged , Humans , Bronchial Fistula/physiopathology , Bronchial Fistula , Aneurysm/diagnosis , Aneurysm , Tomography, Emission-Computed/methods , Angiography/methods , Polytetrafluoroethylene/therapeutic use , Bronchoscopy/methods , Radiography, Thoracic , Angioplasty , Aorta/surgery , Hemoptysis/diagnosis , Hemoptysis/therapy , Aorta , Hemoptysis/epidemiology , Hemoptysis
3.
J Biomed Mater Res A ; 78(3): 629-37, 2006 Sep 01.
Article in English | MEDLINE | ID: mdl-16788976

ABSTRACT

A new composite bone cement designated "G2B1" was developed for percutaneous transpedicular vertebroplasty. G2B1 contains beta tricalcium phosphate particles and methylmethacrylate-methylacrylate copolymer as the powder components, and methylmethacrylate, urethane dimethacrylate, and tetrahydrofurfuryl methacrylate as the liquid components. Biocompatibility and osteoconductivity were evaluated using scanning electron microscopy, contact microradiography, and Giemsa surface staining 4, 8, 12, 26, and 52 weeks after implantation into rat tibiae. To evaluate osteoconductivity, affinity indices (%) were calculated. Scanning electron microscopy and contact microradiography revealed that bone contact with G2B1 was attained within 4 weeks (affinity index: 50.2 +/- 11.8 at 4 weeks) and at most of the margin within 26 weeks (affinity index: 87.4 +/- 7.2 at 26 weeks). Specifically, G2B1 contacted bone via a wide calcium-phosphate-rich layer, and its degradation started within 8 weeks, mainly in the marginal area. Giemsa surface staining showed that there was almost no inflammatory reaction around the G2B1. These results indicate that G2B1 is a biocompatible and osteoconductive bone cement.


Subject(s)
Bone Substitutes , Calcium Phosphates , Spine/surgery , Animals , Male , Materials Testing , Polymethyl Methacrylate , Rats , Rats, Wistar
4.
Biomaterials ; 26(33): 6496-505, 2005 Nov.
Article in English | MEDLINE | ID: mdl-15941580

ABSTRACT

Three types of bioactive polymethylmethacrylate (PMMA)-based bone cement containing nano-sized titania (TiO2) particles were prepared, and their mechanical properties and osteoconductivity are evaluated. The three types of bioactive bone cement were T50c, ST50c, and ST60c, which contained 50 wt% TiO2, and 50 and 60 wt% silanized TiO2, respectively. Commercially available PMMA cement (PMMAc) was used as a control. The cements were inserted into rat tibiae and allowed to solidify in situ. After 6 and 12 weeks, tibiae were removed for evaluation of osteoconductivity using scanning electron microscopy (SEM), contact microradiography (CMR), and Giemsa surface staining. SEM revealed that ST60c and ST50c were directly apposed to bone while T50c and PMMAc were not. The osteoconduction of ST60c was significantly better than that of the other cements at each time interval, and the osteoconduction of T50c was no better than that of PMMAc. The compressive strength of ST60c was equivalent to that of PMMAc. These results show that ST60c is a promising material for use as a bone substitute.


Subject(s)
Biocompatible Materials/chemistry , Bone Cements/chemistry , Bone Substitutes/chemistry , Nanostructures/chemistry , Nanotechnology/methods , Titanium/chemistry , Animals , Male , Materials Testing , Microscopy, Electron, Scanning , Polymethyl Methacrylate/chemistry , Rats , Rats, Wistar , Stress, Mechanical , Tensile Strength , Time Factors , X-Rays
5.
J Biomed Mater Res ; 54(4): 491-500, 2001 Mar 15.
Article in English | MEDLINE | ID: mdl-11426593

ABSTRACT

A new bioactive bone cement (designated GBC), consisting of bioactive glass beads as an inorganic filler and polymethylmethacrylate (PMMA) as an organic matrix, has been developed. The purpose of the present study was to examine the effect of the amount of glass bead filler added to GBC on its mechanical and biological properties, and to decide the most suitable content of filler. Serial changes in GBC with time were also examined. The newly designed bioactive beads, consisting of MgO-CaO-SiO2-P2O5-CaF2 glass, were added to the cement in the proportions 30, 40, 50, 60, and 70 wt %. These cements were designated GBC30, GBC40, GBC50, GBC60, and GBC70, respectively. The compressive strength and the elastic modulus of bending of GBC increased as the glass bead content increased. The various types of GBC were packed into the intramedullar canals of rat tibiae to evaluate osteoconductivity, as determined by an affinity index calculated as the length of bone in direct contact with the cement expressed as a percentage of the total length of the cement surface. Rats were killed at 4 and 8 weeks after the operation and the affinity index was calculated for each type of GBC. Histologically, new bone had formed along the surface of all types of GBC within 4 weeks, even in GBC30 containing only 30 wt % of glass beads. At each time interval studied, there was a trend for the affinity index of GBC to increase as the glass bead filler content increased. There was no significant increase of affinity index between GBC60 and GBC70. The affinity indices for all types of GBC increased significantly with time up to 8 weeks. The handling properties of GBC were comparable to those of conventional PMMA bone cement. We conclude that when mechanical properties and osteoconductivity are both taken into consideration, GBC60 is the most suitable formulation; it shows excellent osteoconductivity and sufficient mechanical strength for clinical use.


Subject(s)
Bone Cements , Coated Materials, Biocompatible , Tibia/drug effects , Animals , Bone Cements/chemistry , Bone Cements/pharmacology , Elasticity , Glass , Male , Microscopy, Electron, Scanning , Polymethyl Methacrylate/chemistry , Polymethyl Methacrylate/pharmacology , Rats , Rats, Wistar , Stress, Mechanical , Tibia/ultrastructure
6.
J Biomed Mater Res ; 56(4): 571-7, 2001 Sep 15.
Article in English | MEDLINE | ID: mdl-11400135

ABSTRACT

A new bioactive bone cement, designated GBC, has been developed. It consists of polymethyl methacrylate (PMMA) as an organic matrix and bioactive glass beads as an inorganic filler. The bioactive beads, consisting of MgO--CaO--SiO(2)--P(2)O(5)--CaF(2) glass, have been newly designed, and a novel PMMA powder was selected. The purpose of the present study was to evaluate the effects on mechanical properties and osteoconductivity of adding a phosphoric ester (PE) monomer to the cement as an adhesion-promoting agent. Four kinds of cements were prepared: GBC, GBC with PE (designated GBC/PE), a cement consisting of the same PMMA used in GBC with apatite- and wollastonite-containing glass-ceramic (AW-GC) powder (designated AWC), and AWC with PE (designated AWC/PE). Each filler was added to the cement at 70 wt %. Adding PE to either GBC or AWC resulted in increases in the bending strength and decreases in the Young's modulus compared with the unmodified cements. Cements were packed into the intramedullar canals of rat tibiae to evaluate osteoconductivity as determined by an affinity index. Rats were sacrificed at 4 and 8 weeks after operation. The affinity index (length of bone in direct contact with the cement expressed as a percentage of the total length of the cement surface) was calculated for each cement. Adding PE to either GBC or AWC resulted in significant increases in the affinity index compared with the unmodified cements. The affinity index for GBC was significantly higher than that of AWC, and that for GBC/PE was also significantly higher than that of AWC/PE. The affinity indices for each cement increased significantly with time up to 8 weeks. Our study revealed that the higher osteoconductivity of GBC/PE was due to the large alkyl group in the PE monomer, to the hydrophilicity of the phosphoric acid in the PE monomer, and to the higher bioactivity of the bioactive glass beads at the cement surface. GBC/PE shows promise as an alternative bone cement with improved properties compared with conventional PMMA bone cement.


Subject(s)
Bone Cements , Organophosphates , Animals , Bone Remodeling , Male , Rats , Rats, Wistar , Surface Properties
7.
J Biomed Mater Res ; 56(3): 452-8, 2001 Sep 05.
Article in English | MEDLINE | ID: mdl-11372064

ABSTRACT

A bioactive bone cement (designated GBC), consisting of bioactive glass beads as an inorganic filler and poly(methyl methacrylate) (PMMA) as an organic matrix, has been developed. The purpose of the present study was to examine the effect of the size of the glass beads added as a filler to GBC on its mechanical properties and osteoconductivity. Serial changes in GBC with time were also examined. Four different sizes of beads (mean diameters 4, 5, 9, and 13 microm) consisting of MgO-CaO-SiO(2)-P(2)O(5)-CaF(2) glass were added to four GBC mixes in a proportion of 70 wt %. The bending strength of GBC increased as the mean size of the glass beads decreased. The four GBC mixes were packed into the intramedullary canals of rat tibiae to evaluate osteoconductivity, as determined by an affinity index. Rats were sacrificed at 4 and 8 weeks after surgery. The affinity index, which equaled the length of bone in direct contact with the cement surface expressed as a percentage of the total length of the cement surface, was calculated for each cement at each interval. Histologically, new bone had formed along the surface of all types of GBC within 4 weeks. At each time interval, there was a trend for the affinity index of GBC to increase as the mean glass bead size decreased. The affinity indices for all types of GBC increased significantly with time up to 8 weeks. The handling properties of GBC were comparable to those of conventional PMMA bone cement. We concluded that, considering both mechanical properties and osteoconductivity, GBC made with smaller sized glass beads as filler was the most suitable cement. GBC shows promise as an alternative bone cement with improved properties compared to conventional PMMA bone cement.


Subject(s)
Bone Cements , Animals , Bone Remodeling , Male , Rats , Rats, Wistar , Stress, Mechanical , Surface Properties
8.
J Biomed Mater Res ; 55(3): 277-84, 2001 Jun 05.
Article in English | MEDLINE | ID: mdl-11255180

ABSTRACT

A novel bioactive bone cement (GBC) was developed with newly designed bioactive MgO-CaO-SiO(2)-P(2)O(5)-CaF(2) glass beads as the inorganic filler and high molecular weight poly(methyl methacrylate) as the organic matrix. The purpose of this study was to examine the relationship between the amount of the silane coupling agent (gamma-methacryloxy propyl trimethoxy silane) used to treat the glass beads and the mechanical and biological properties of the resultant bone cement. Serial changes in the cement over time were also investigated. Five different kinds of cement, in which the glass beads were treated with different amounts of the coupling agent, were prepared. The quantities of the coupling agent were 0 (control), 0.1, 0.2, 0.5, and 1.0% (w/w) of the glass beads, and the cements were designated GBCs0, GBCs0.1, GBCs0.2, GBCs0.5, and GBCs1.0, respectively. After soaking in water at 75 degrees C for 5 days, GBCs0.1 and GBCs0.2 had significantly higher bending strengths than the other cements. Each GBC was packed into intramedullar canals of rat tibiae to evaluate osteoconductivity, as determined by affinity indices. Rats were killed 4 and 8 weeks after the operation. The affinity index was calculated for each GBC and equaled the length of bone in direct contact with the cement and was expressed as a percentage of the total length of the cement surface. Histologically, new bone had formed along all of the GBC surfaces within 4 weeks. At each time interval, a decreasing trend in the affinity index of GBC was found as the amount of the coupling agent increased. At 8 weeks, no significant change in the affinity index occurred when the amount of the coupling agent increased from 0 to 0.2%, whereas a significant decrease in the affinity index was observed when the amount of the coupling agent increased from 0 to 0.5 or 1.0%. The affinity indices for all the GBCs increased significantly up to 8 weeks. When both the mechanical properties and osteoconductivity were taken into consideration, GBCs0.1 and GBCs0.2 were the best cements, and they showed excellent osteoconductivity and strong enough mechanical properties for clinical use.


Subject(s)
Bone Cements , Animals , Biomechanical Phenomena , Bone Cements/chemistry , Glass , Male , Materials Testing , Microscopy, Electron, Scanning , Osseointegration , Polymethyl Methacrylate , Rats , Rats, Wistar , Silanes
9.
Biomaterials ; 21(21): 2137-46, 2000 Nov.
Article in English | MEDLINE | ID: mdl-10985486

ABSTRACT

We reported previously that a bioactive PMMA-based cement was obtained by using a dry method of silanation of apatite-wollastonite glass ceramic (AW-GC) particles, and using high molecular weight PMMA particles. But handling and mechanical properties of the cement were poor (Mousa et al., J Biomed Mater Res 1999;47:336-44). In the present study, we investigated the effect of the characteristics of PMMA powder on the cement. Different cements containing different PMMA powders (CMW1, Surgical Simplex, Palacos-R and other two types of PMMA powders with Mw 270,000 and 1,200,000) and AW-GC filler in 70 wt% ratio except Palacos-R (abbreviated as B-CMW1 and B-Surg Simp, B-Palacos 50 [50 wt% AW-GC filler] and B-Palacos 70 [70 wt% AW-GC filler], B-270 and B-1200) were made. Dough and setting times of B-CMW1, B-Surg Simp B-270 and B-1200 were similar to the commercial CMW1 cement which did not contain bioactive powder (C-CMW1), but B-palacos which contained large PMMA beads with high Mw had delayed setting time. B-270 had the highest bending strength among the tested cements. After 4 and 8 weeks of implantation in the medullary canals of rat tibiae, the bone-cement interface was examined using SEM. The affinity index of B-1200 was significantly higher than the other types of cements. B-270 showed good combination of handling properties, high mechanical properties and showed higher bioactivity with minimal soft tissue interposition between bone and cement compared with commercial PMMA bone cement. This may increase the strength of the bone-cement interface and increase the longevity of cemented arthroplasties.


Subject(s)
Bone Cements/chemistry , Polymethyl Methacrylate/chemistry , Animals , Male , Materials Testing , Microscopy, Electron , Microspheres , Molecular Weight , Pliability , Powders , Rats , Rats, Wistar , Tibia/surgery , Time Factors , Viscosity
10.
J Biomed Mater Res ; 51(2): 258-72, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10825226

ABSTRACT

A new bioactive bone cement (designated GBC) consisting of polymethyl methacrylate (PMMA) as an organic matrix and bioactive glass beads as an inorganic filler has been developed. The bioactive beads, consisting of MgO-CaO-SiO(2)-P(2)O(5)-CaF(2) glass, have been newly designed, and a novel PMMA powder was selected. The purpose of the present study was to compare this new bone cement GBC's mechanical properties in vitro and its osteoconductivity in vivo with cements consisting of the same matrix as GBC and either apatite- and wollastonite-containing glass-ceramic (AW-GC) powder (designated AWC) or sintered hydroxyapatite (HA) powder (HAC). Each filler added to the cements amounted to 70 wt %. The bending strength of GBC was significantly higher than that of AWC and HAC (p < 0.0001). Cements were packed into intramedullar canals of rat tibiae in order to evaluate osteoconductivity as determined by an affinity index. Rats were sacrificed at 2, 4, and 8 weeks after operation. An affinity index, which equaled the length of bone in direct contact with the cement expressed as a percentage of the total length of the cement surface, was calculated for each cement. At each time interval studied, GBC showed a significantly higher affinity index than AWC or HAC up to 8 weeks after implantation (p < 0.03). The value for GBC increased significantly with time up to 8 weeks (p < 0.006). The handling property of GBC was comparable with that of PMMA bone cement. Our study revealed that the higher osteoconductivity of GBC was due to the higher bioactivity of the bioactive glass beads at the cement surface and the lower solubility of the new PMMA powder to MMA monomer. In addition, it was found that the smaller spherical shape and glassy phase of the glass beads gave GBC strong enough mechanical properties to be useful under weight-bearing conditions. GBC shows promise as an alternative with improved properties to the conventionally used PMMA bone cement.


Subject(s)
Apatites/chemistry , Bone Cements/chemistry , Bone Substitutes , Ceramics/chemistry , Glass , Polymethyl Methacrylate/chemistry , Silicic Acid/chemistry , Animals , Apatites/pharmacology , Bone Cements/pharmacology , Ceramics/pharmacology , Durapatite/pharmacology , Elasticity , Male , Microscopy, Electron, Scanning , Osteogenesis/drug effects , Polymethyl Methacrylate/pharmacology , Rats , Rats, Wistar , Silicic Acid/pharmacology , Tensile Strength , Tibial Fractures/pathology , Tibial Fractures/surgery
11.
J Biomed Mater Res ; 53(1): 51-61, 2000.
Article in English | MEDLINE | ID: mdl-10634952

ABSTRACT

The fact that bisphenol-a-glycidyl methacrylate (bis-GMA)-based cements contain an uncured surface is believed to play an important role when determining the surface curing properties of the cements. Therefore, in the present study, the bone-bonding strength of cement plates having an uncured surface on one side and a cured surface on the other side has been evaluated. These cement plates were composites of a bis-GMA-based resin with either an apatite- and wollastonite-containing glass-ceramic (AW-GC) powder or a hydroxyapatite (HA) powder, respectively designated AWC and HAC. The amount of each of these powders in a composite cement was 70 wt %. We formulate the hypothesis that the uncured surface of a cement plate is bioactive having bone-bonding properties. The goal of the present study was to indicate the bone-bonding strength of the uncured surfaces of AWC and HAC and compare the strength with the respective cured surfaces by a detaching in vivo test, as well as to histologically examine the bone-cement interface. Each plate has been implanted into the tibiae of male Japanese white rabbits, taking care to retain the surface properties, and the so-called "failure load has been measured using a detaching test followed 8 weeks after implantation. The failure load for AWC-plates at the uncured surface (2.05 +/- 1.11 kgf, n = 8) was significantly higher than AWC at its cured surface side (0.28 +/- 0.64 kgf, n = 8). The failure load for HAC-plates at the uncured surfaces (1.40 +/- 0.68 kgf, n = 8) was significantly higher than HAC at its cured surface (0.00 +/- 0.00 kgf, n = 8). Failure loads for AWC at its uncured and cured surfaces were both higher than for HAC, although not significantly. Direct bone formation has been observed histologically for both AWC and HAC on the uncured surfaces, and a Ca-P-rich layer was observed only at the uncured surface of AWC. These findings strongly suggest that uncured surfaces are useful for exposing a bioactive filler on a surface of composites, being very effective in inducing bone bonding.


Subject(s)
Bone Cements , Animals , Bisphenol A-Glycidyl Methacrylate , Calcium Compounds , Durapatite , Glass , Male , Materials Testing , Microscopy, Electron, Scanning , Powders , Rabbits , Silicates , Surface Properties
12.
J Biomed Mater Res ; 49(3): 319-27, 2000 Mar 05.
Article in English | MEDLINE | ID: mdl-10602064

ABSTRACT

Three composites consisting of alumina powder dispersed in a bisphenol-a-glycidyl methacrylate (Bis-GMA) matrix were prepared and evaluated to assess the effect of alumina powder content on the mechanical properties and osteoconductivity of the composite. The alumina powder composites (APC) consisted of alumina powder (AL-P) as the inorganic filler dispersed in a Bis-GMA matrix that was solidified by a radical polymerization process. Prior to polymerization the AL-P was mixed with the monomers in proportions of 50%, 70%, and 80% by weight (APC50, APC70, and APC80). A fused silica-glass-filled composite containing 70% glass by weight (SGC70) was used as a control. The compressive and bending strengths, the elastic modulus in bending, and the bending strain of the composites increased as the AL-P content increased. We also evaluated the composites in vivo by implanting them into the medullary canals of rat tibiae. To compare the osteoconductivity of the composites, an affinity index was calculated for each composite; the affinity index equals the length of a bone in direct apposition to the composite and is expressed as a percentage of the total length of the composite surface. Microradiographic examination for periods of up to 26 weeks after implantation revealed that APC50, APC70, and APC80 all exhibited excellent osteoconductivity and made direct contact with the bone with no interposed soft tissues. However, the higher the AL-P content of the composite, the higher the osteoconductivity, especially at 4 weeks after the operation. Moreover, the amount of bone directly apposed to the composite surface increased with time. In contrast, little bone formation was seen on the surface of SGC70, even after 26 weeks. Observation by scanning electron microscope-energy dispersive X-ray microanalysis demonstrated that bone made direct contact with the APC surface through a layer containing calcium, phosphorus, and alumina powder. These results suggest that APC shows promise as a basis for developing mechanically strong and highly osteoconductive composites.


Subject(s)
Aluminum Oxide , Bisphenol A-Glycidyl Methacrylate , Bone Cements , Animals , Biocompatible Materials , Biomechanical Phenomena , Bone Substitutes , Electron Probe Microanalysis , Male , Materials Testing , Microscopy, Electron, Scanning , Osseointegration , Powders , Rats , Rats, Wistar , Tibia/anatomy & histology , Tibia/physiology , Tibia/surgery
13.
J Biomed Mater Res ; 49(1): 106-11, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10559752

ABSTRACT

We developed a composite (ABC) consisting of alumina bead powder as an inorganic filler and bisphenol-a-glycidyl dimethacrylate (Bis-GMA)-based resin as an organic matrix. Alumina bead powder was manufactured by fusing crushed alpha-alumina powder and quenching it. The beads took a spherical form 3 microm in average diameter. The proportion of filler in the composites was 70% w/w. The composite was implanted into rat tibiae and cured in situ. Specimens were prepared 1, 2, 4, and 8 weeks after the operation and observed by transmission electron microscopy. The results were compared with those of a bone composite made of alpha-alumina powder (alpha-ALC). In ABC-implanted tibiae, the uncured surface layer of Bis-GMA-based resin was completely filled with newly formed bonelike tissue 2 weeks after implantation. The alumina bead fillers were surrounded by and in contact with bonelike tissue. No intervening soft tissue was seen. In alpha-ALC-implanted tibiae, a gap was always observed between the alpha-ALC and the bonelike tissue. These results indicate that the ABC has osteoconductivity, although the precise mechanism is still unclear.


Subject(s)
Aluminum Oxide/chemistry , Bone Cements/chemistry , Bone and Bones/ultrastructure , Composite Resins/chemistry , Animals , Extracellular Matrix/drug effects , Extracellular Matrix/ultrastructure , Male , Materials Testing , Microscopy, Electron , Microspheres , Rats , Rats, Wistar , Surface Properties , Time Factors
14.
J Biomed Mater Res ; 46(4): 447-57, 1999 Sep 15.
Article in English | MEDLINE | ID: mdl-10398005

ABSTRACT

We took three types of bioactive bone cement (designated AWC, HAC, and TCPC), each with a different bioactive filler, and evaluated the influence of each filler on the mechanical properties and osteoconductivity of the cement. The cements consisted of bisphenol-a-glycidyl methacrylate-based (Bis-GMA based) monomers as an organic matrix, with a bioactive filler of apatite/wollastonite containing glass-ceramic (AW-GC) or sintered hydroxyapatite (HA) or beta-tricalcium phosphate (beta-TCP) powder. Each filler was mixed with the monomers in proportions of 50, 70, and 80% (w/w), giving a total of nine cement subgroups. The nine subgroups were designated AWC50, AWC70, AWC80, HAC50, HAC70, HAC80, TCPC50, TCPC70, and TCPC80. The compressive and bending strengths of AWC were found to be higher than those of HAC and TCPC for all bioactive filler contents. We also evaluated the cements in vivo by packing them into the intramedullary canals of rat tibiae. To compare the osteoconductivity of the cements, an affinity index was calculated for each cement; it equaled the length of bone in direct apposition to the cement, expressed as a percentage of the total length of the cement surface. Microradiographic examination up to 26 weeks after implantation revealed that AWC showed a higher affinity index than HAC and TCPC for each filler content although the affinity indices of all nine subgroups (especially the AWC and HAC subgroups) increased with time. New bone had formed along the AWC surface within 4 weeks, even in the cement containing AW-GC filler at only 50% (w/w); observation of the cement-bone interfaces using a scanning electron microscope showed that all the cements had directly contacted the bone. At 4 weeks the AWC had bonded to the bone via a 10 micron-thick reactive layer; the width of the layer, in which partly degraded AW-GC particles were seen, became slightly thicker with time. On the other hand, in the HAC- and TCPC-implanted tibiae, some particles on the cement surface were surrounded by new bone and partly absorbed or degraded. The results suggest that the stronger bonding between the inorganic filler and the organic matrix in the AWC cements gave them better mechanical properties. The results also indicate that the higher osteoconductivity of AWC was caused by the higher reactivity of the AW-GC powder on the cement surface.


Subject(s)
Apatites/chemistry , Bisphenol A-Glycidyl Methacrylate/chemistry , Bone Cements/chemistry , Calcium Phosphates/chemistry , Ceramics/chemistry , Durapatite/chemistry , Silicic Acid/chemistry , Animals , Compressive Strength , Elasticity , Male , Materials Testing , Mechanics , Osseointegration , Pliability , Prostheses and Implants , Rats , Rats, Wistar , Stress, Mechanical , Tensile Strength , Tibia/surgery
15.
J Biomed Mater Res ; 46(2): 287-300, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10380008

ABSTRACT

Previously we developed an alumina bead composite (ABC) consisting of alumina bead powder (AL-P) and bisphenol-alpha-glycidyl methacrylate (Bis-GMA)-based resin and reported its excellent osteoconductivity in rat tibiae. In the present study, are evaluated histologically and mechanically the effect of alumina crystallinity on the osteoconductivity and bone-bonding strength of the composite. AL-P was manufactured by fusing crushed alpha-alumina powder and quenching it. The AL-P was composed mainly of amorphous and delta-crystal phases of alumina. Its average particle size was 3.5 microm, and it took a spherical form. Another composite (alpha ALC), filled with pure alpha-alumina powder (alpha AL-P), was used as a referential material. The proportion of powder added to each composite was 70% w/w. Mechanical testing of ABC and alpha ALC indicated that they would be strong enough for use under weight-bearing conditions. The affinity indices for ABC, determined using male Wistar rat tibiae, were significantly higher than those for alpha ALC (p < 0.0001) up to 8 weeks. Composite plates (15 x 10 x 2 mm) that had an uncured surface layer on one side were made in situ in a rectangular mold. One of the plates was implanted into the proximal metaphysis of the tibia of a male Japanese white rabbit, and the failure load was measured by a detaching test 10 weeks after implantation. The failure loads for ABC on its uncured surface [1.91+/-1.23 kgf (n = 8)] were significantly higher than those for alpha ALC on its uncured surface [0.35+/-0.33 kgf (n = 8); (p < 0.0001)], and they also were significantly higher than those for ABC on the other (cured surface) side (p < 0.0001). Histological examinations using rabbit tibiae revealed bone ingrowth into the composite only on the uncured surface of ABC. This study revealed that the amorphous phase of alumina and formation of an uncured surface layer are needed for the osteoconductive and bone-bonding ability of ABC. ABC shows promise as a basis for the development of a highly osteoconductive and mechanically strong biomaterial.


Subject(s)
Aluminum Oxide , Bisphenol A-Glycidyl Methacrylate , Bone and Bones/physiology , Animals , Body Fluids , Bone Conduction , Bone Development , Bone and Bones/anatomy & histology , Elasticity , Male , Materials Testing , Microscopy, Electron, Scanning , Rabbits , Rats , Rats, Wistar , Surface Properties , Tensile Strength
16.
Int J Radiat Oncol Biol Phys ; 43(4): 777-82, 1999 Mar 01.
Article in English | MEDLINE | ID: mdl-10098432

ABSTRACT

PURPOSE: To evaluate the prognostic value of tumor diameter/volume and pelvic node status assessed by magnetic resonance imaging (MRI) in patients with uterine cervical cancer treated with radiation therapy. METHODS AND MATERIALS: Forty-four patients with intact uterine cervical squamous carcinoma treated with a combination of external irradiation and high-dose-rate intracavitary therapy were analyzed. Actuarial disease-free survival (DFS), pelvic control rate (PC), and distant metastasis-free rate (DMF) were analyzed by tumor diameter, volume, and pelvic node status assessed by pretreatment MRI. RESULTS: Anteroposterior (AP) and lateral (RL) tumor diameter significantly affected DFS. The 2-year DFS was 74% for patients with < 40 mm in AP diameter tumor, and 24% for > or = 40 mm tumor (p = 0.02). Whereas PC was not influenced, DMF was significantly affected by AP tumor diameter. Tumor volume did not significantly affect any endpoints. Patients with enlarged pelvic nodes had significantly poorer outcome compared to those with none on PC, DMF, and DFS. The 2-year DFS was 78% for node-negative, and 10% for node-positive patients (p = 0.0001). CONCLUSION: AP tumor diameter and pelvic lymph node status assessed by MRI were the significant prognostic factors in uterine cervical cancer treated with irradiation. Prognostic value of tumor volume should be reassessed prospectively with an appropriate imaging technique. AP tumor diameter predominantly affected the incidence of distant metastasis, and lymph node status affected both pelvic control and distant metastasis.


Subject(s)
Carcinoma, Squamous Cell/pathology , Uterine Cervical Neoplasms/pathology , Adult , Aged , Aged, 80 and over , Carcinoma, Squamous Cell/mortality , Carcinoma, Squamous Cell/radiotherapy , Carcinoma, Squamous Cell/secondary , Female , Humans , Linear Models , Lymphatic Metastasis , Magnetic Resonance Imaging , Middle Aged , Neoplasm Recurrence, Local , Neoplasm Staging , Pelvis , Prognosis , Retrospective Studies , Treatment Outcome , Uterine Cervical Neoplasms/mortality , Uterine Cervical Neoplasms/radiotherapy
17.
J Gastroenterol ; 33(4): 593-6, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9719250

ABSTRACT

Combined hepatocellular (HCC) and cholangiocellular carcinoma (CCC) (mixed carcinoma) is a rare subtype of primary hepatic carcinoma. We report a case of mixed carcinoma that developed in a non-cirrhotic liver, in a patient who was serologically negative for both hepatitis B and C viruses. A 65-year-old Japanese woman with a 25-year history of chronic rheumatoid arthritis had been treated with steroids and anti-inflammatory drugs, and was diagnosed by ultrasonography with an asymptomatic solitary tumor in the right lobe of the liver. On computed tomography scan and hepatic arteriography, the tumor was well enhanced by contrast medium in the early phase. Based on the findings of elevated serum alpha-feto protein (AFP, 245 ng/ml) and normal carcino-embryonic antigen (CEA, 2.6 ng/ml) levels, a preoperative diagnosis of hepatocellular carcinoma was made. Right lobectomy of the liver was performed on January 7, 1997. Histological examination showed that the resected tumor consisted of combined CCC cells and HCC cells in an intermingled form, with CCC being far more dominant than HCC. The tumor was therefore determined to be a combined carcinoma, subclassified as intermingled type. This case appears to indicate that mixed type carcinoma developed in a non-cirrhotic liver, with CCC being dominant; such a finding is extremely unusual, based on previously published reports.


Subject(s)
Carcinoma, Hepatocellular/diagnosis , Cholangiocarcinoma/diagnosis , Liver Neoplasms/diagnosis , Aged , Carcinoma, Hepatocellular/diagnostic imaging , Carcinoma, Hepatocellular/pathology , Cholangiocarcinoma/diagnostic imaging , Cholangiocarcinoma/pathology , Diagnosis, Differential , Female , Humans , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/pathology , Radiography
19.
Gynecol Oncol ; 65(3): 421-4, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9190968

ABSTRACT

We analyzed long-term treatment results in 51 patients with locally advanced uterine cervical carcinoma (IIB, 4; IIIB, 43; IVA, 4) treated with neoadjuvant intra-arterial (I-A) chemotherapy (cisplatin) via the uterine artery and irradiation. Thirty patients (58.8%) developed recurrence. Twelve had pelvic recurrence alone, 8 had distant metastases alone, and 10 had both pelvic and distant failure. The 5-year cumulative pelvic control rate, absolute survival rate, and disease-free survival rate were 55.3, 47.1, and 39.4%, respectively. Eight of 51 patients (15.7%) suffered late complications. These results suggest that our neoadjuvant I-A chemotherapy prior to irradiation has limited additional value for long-term prognosis in patients with locally advanced uterine cervical carcinoma.


Subject(s)
Antineoplastic Agents/administration & dosage , Cisplatin/administration & dosage , Uterine Cervical Neoplasms/drug therapy , Uterine Cervical Neoplasms/radiotherapy , Adult , Aged , Chemotherapy, Adjuvant , Female , Humans , Injections, Intra-Arterial , Middle Aged , Neoplasm Metastasis , Neoplasm Recurrence, Local/epidemiology , Survival Rate , Time Factors , Treatment Failure , Uterine Cervical Neoplasms/mortality , Uterine Cervical Neoplasms/pathology
20.
Nihon Igaku Hoshasen Gakkai Zasshi ; 56(7): 490-5, 1996 Jun.
Article in Japanese | MEDLINE | ID: mdl-8692665

ABSTRACT

We evaluated 35 patients with cerebral palsy on the basis of MR imaging findings in the brain. The types of palsy were spastic quadriplegia (n = 11), spastic diplegia (n = 9), spastic hemiplegia (n = 2), double hemiplegia (n = 1), athetosis (n = 10) and mixed (n = 2). Of all patients, 28 (80%) generated abnormal findings. In spastic quadriplegia, although eight cases revealed severe brain damage, two cases showed no abnormal findings in the brain. One of the three had cervical cord compression caused by atlanto-axial subluxation. In spastic diplegia, the findings were divided according to whether the patient was born at term or preterm. If the patient had been born prematurely, the findings showed periventricular leukomalacia and abnormally high intensity in the posterior limbs of the internal capsule on T2-weighted images. MR imaging in spastic hemiplegia revealed cerebral infarction. In the athetoid type, half of all cases showed either no abnormal findings or slight widening of the lateral ventricle. Three cases showed abnormal signals of the basal ganglia. The reason why athetoid-type palsy did not show severe abnormality is unknown. We believe that MR imaging is a useful diagnostic modality to detect damage in the brain in cerebral palsy and plays an important role in the differentiation of cerebral palsy from the spastic palsy disease.


Subject(s)
Brain/pathology , Cerebral Palsy/diagnosis , Adolescent , Adult , Child , Child, Preschool , Female , Humans , Magnetic Resonance Imaging , Male
SELECTION OF CITATIONS
SEARCH DETAIL
...