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1.
Osteoporos Int ; 28(3): 1013-1020, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-27826645

RESUMEN

Fracture liaison services often perform laboratory testing, but these results may be altered by surgery. In 40 hip arthroplasty patients, many laboratory parameters of bone health relevance were reduced by 8-22% on the first post-operative day. Laboratory results obtained in the immediate post-surgery interval do not reliably ascertain baseline status. INTRODUCTION: As secondary causes of osteoporosis are common, fracture liaison services often perform laboratory testing in the immediate post-fracture interval. We hypothesized that laboratory results obtained shortly after surgery may not accurately ascertain baseline status. If true, such alterations might confound subsequent fracture prevention efforts. METHODS: Patients undergoing elective total hip arthroplasty were studied as a surrogate for hip fracture patients. Blood and urine were obtained 2 weeks before surgery, before anesthetic induction, on post-operative day one, and 6 weeks after surgery. Serum total and free 25-hydroxyvitamin D (25(OH)D), vitamin D-binding protein (DBP), calcium, creatinine, albumin (Alb), alkaline phosphatase (ALP), plasma hemoglobin (Hgb) and urinary DBP/creatinine ratio (UDBP/Cr) were measured. RESULTS: Forty volunteers (28 women; 12 men) with mean age of 65.7 [8.7] years were studied. Laboratory results were stable from 2 weeks before to the day of surgery. On the first day after surgery, total 25(OH)D, DBP, calcium, creatinine, ALP, and Alb declined 8-22% (p < 0.0001); free 25(OH)D and Hgb declined by 8 and 15% (p < 0.01), respectively; and UDBP/Cr increased 32% (p < 0.01). Using a 25(OH)D <30 ng/mL threshold, vitamin D inadequacy prevalence increased from 38% before surgery to 68% the day after (p < 0.001). All laboratory values returned to baseline at 6 weeks after surgery. CONCLUSIONS: Laboratory values are reduced immediately following elective total hip arthroplasty. Testing at that time does not accurately ascertain baseline status and may lead to elevated estimates of vitamin D inadequacy, incorrect interventions, and misallocation of healthcare resources.


Asunto(s)
Artroplastia de Reemplazo de Cadera/efectos adversos , Osteoartritis de la Cadera/cirugía , Deficiencia de Vitamina D/diagnóstico , Deficiencia de Vitamina D/etiología , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Reacciones Falso Positivas , Femenino , Fracturas de Cadera/etiología , Fracturas de Cadera/cirugía , Humanos , Masculino , Persona de Mediana Edad , Osteoporosis/diagnóstico , Osteoporosis/etiología , Fracturas Osteoporóticas/diagnóstico , Fracturas Osteoporóticas/etiología , Cuidados Posoperatorios/métodos , Periodo Posoperatorio , Estudios Prospectivos , Vitamina D/análogos & derivados , Vitamina D/sangre , Deficiencia de Vitamina D/sangre
2.
J Sci Food Agric ; 93(2): 227-37, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22806403

RESUMEN

BACKGROUND: The postharvest quality and shelf life of spinach are greatly influenced by cultural practices. Reduced spinach shelf life is a common quandary in the Salinas Valley, California, where current agronomic practices depend on high nitrogen (N) rates. This study aimed to describe the postharvest fracture properties of spinach leaves in relation to N fertilization, leaf age and spinach cultivar. RESULTS: Force-displacement curves, generated by a puncture test, showed a negative correlation between N fertilization and the toughness, stiffness and strength of spinach leaves (P > 0.05). Younger leaves (leaves 12 and 16) from all N treatments were tougher than older leaves (leaves 6 and 8) (P > 0.05). Leaves from the 50 and 75 ppm total N treatments irrespective of spinach cultivar had higher fracture properties and nutritional quality than leaves from other N treatments (P > 0.05). Total alcohol-insoluble residues (AIR) and pectins were present at higher concentrations in low-N grown plants. These plants also had smaller cells and intercellular spaces than high-N grown leaves (P > 0.05). CONCLUSION: Observed changes in physicochemical and mechanical properties of spinach leaves due to excess nitrogen fertilization were significantly associated with greater postharvest leaf fragility and lower nutritional quality.


Asunto(s)
Fertilizantes , Calidad de los Alimentos , Ciclo del Nitrógeno , Hojas de la Planta/química , Hojas de la Planta/crecimiento & desarrollo , Spinacia oleracea/química , Spinacia oleracea/crecimiento & desarrollo , California , Tamaño de la Célula , Pared Celular/química , Pared Celular/metabolismo , Fenómenos Químicos , Espacio Extracelular , Fertilizantes/efectos adversos , Humanos , Fenómenos Mecánicos , Valor Nutritivo , Pectinas/análisis , Pectinas/metabolismo , Pigmentos Biológicos/análisis , Pigmentos Biológicos/metabolismo , Hojas de la Planta/citología , Hojas de la Planta/metabolismo , Especificidad de la Especie , Spinacia oleracea/citología , Spinacia oleracea/metabolismo , Agua/análisis
3.
Chemistry ; 15(10): 2270-2, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19180598

RESUMEN

Chloride avoided! A new chloride-free method to synthesise ionic liquids (ILs) with mixed borate anions, starting from tetrafluoroborate compounds, has been developed and a number of examples including some new ILs are presented (see scheme; [CAT](+) = cation). It is widely applicable and allows access to mixed borates with various types of ligands in a straightforward manner.

4.
Cancer Res ; 47(20): 5377-81, 1987 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-3115567

RESUMEN

3F8 is a murine IgG3 monoclonal antibody specific for the antigen disialoganglioside GD2. Immunofluorescence staining showed strong binding of 3F8 to 15 of 17 human osteosarcomas, including primary and metastatic tumors. The targeting potentials of the native monoclonal antibody (3F8) and the F(ab')2 fragment (p-3F8) were tested in BALB/c athymic nude mice xenografted with human osteosarcomas. After radiolabeling with iodine using the chloramine T method, both 3F8 and p-3F8 retained immunoreactivities. The irrelevant IgG3 antibody TIB114 and its F(ab')2 fragment were used as negative controls. A Ewing's sarcoma xenograft, which was low in GD2 antigen, was also studied for comparison. Mice were sacrificed 1 day and 4 days after i.v. antibody injection. 3F8 and p-3F8 showed preferential accumulation in osteosarcoma over normal tissues with tumor:nontumor ratios of 2.7-58:1 and 1.4-82:1, respectively, on Day 1. These ratios improved to 10-163:1 and 6.0-75:1 on Day 4. The intact antibody 3F8 showed selective tumor uptake with a much higher percentage of injected dose per g than the fragment p-3F8 and exhibited a longer tissue half-life than p-3F8. These data indicate that anti-GD2 monoclonal antibodies may be useful for imaging and targeted therapy of human osteogenic sarcoma. The F(ab')2 fragment has the advantage of achieving favorable tumor:nontumor ratios sooner after antibody injection while the intact antibody shows better retention by tumor tissues.


Asunto(s)
Anticuerpos Monoclonales/análisis , Neoplasias Óseas/inmunología , Gangliósidos/inmunología , Osteosarcoma/inmunología , Animales , Autorradiografía , Técnica del Anticuerpo Fluorescente , Semivida , Humanos , Radioisótopos de Yodo/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Sarcoma de Ewing/inmunología , Distribución Tisular
5.
Hum Gene Ther ; 8(7): 875-91, 1997 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-9143914

RESUMEN

The objective of this Phase I study is to assess the acute and long-term toxicities of intradermal vaccination of cancer patients with lethally-irradiated tumor cells that have been transfected by particle-mediated gene transfer (PMGT) with gold particles coated with human granulocyte-macrophage colony stimulating factor (GM-CSF) DNA in a plasmid expression vector. The GM-CSF DNA-coated gold particles are delivered to tumor cells using helium pressure with a hand held gene delivery device. Preclinical studies have demonstrated that vaccination of mice with irradiated, GM-CSF-transfected melanoma cells provided protection from subsequent challenges with non-irradiated, non-transfected tumor cells. Ongoing human tumor immunotherapy studies use patients' melanoma or renal carcinoma cells transfected with a retroviral vector containing GM-CSF cDNA as a vaccine to elicit anti-tumor immune responses. PMGT transfection, unlike retroviral transfection, does not require tumor cells to proliferate in vitro to undergo gene transfer. Instead, tumor tissue can be dissociated into small tissue clumps or cell aggregates and then immediately transfected using the gene gun. PMGT physically inserts the DNA without the need for cell surface interaction with viral components or exposure of the patient to viral antigens. As described in this protocol, fresh human sarcoma and melanoma specimens can be transfected with the GM-CSF DNA-coated gold particles with subsequent production of biologically active GM-CSF protein. In this study tumor tissue will be obtained from patients with melanoma or sarcoma. Tumor tissue will be dissociated, irradiated, and transfected with GM-CSF DNA by PMGT. In this ascending dosage study, two dose levels of GM-CSF DNA will be studied in 2 groups of 6 patients each. Patients will receive two intradermal injections of the irradiated, transfected tumor in a single extremity. On days 3 and 14 post-vaccination, patients will undergo surgical excision of the vaccination sites to assess GM-CSF production and infiltration of immune effector cells. On Day 25, patients will undergo DTH testing with intradermal injection in their opposite extremity of 5 x 10(6) irradiated non-transfected autologous tumor cells cryopreserved at the time of vaccine preparation. This injection site will be assessed on day 28 post-vaccination and surgical excision of the DTH testing site will be performed on day 28 if a positive reaction is noted. The patients will be observed for local and systemic toxicity on days 2, 3, 5, 8, 14, 25, and 28 after the vaccination. Restaging of the patients' disease and long term toxicity evaluation will be performed at 3, 6, and 12 months and then yearly.


Asunto(s)
Vacunas contra el Cáncer/uso terapéutico , Técnicas de Transferencia de Gen , Terapia Genética , Factor Estimulante de Colonias de Granulocitos y Macrófagos/genética , Melanoma/terapia , Sarcoma/terapia , Animales , Vacunas contra el Cáncer/efectos adversos , Protocolos Clínicos , Ensayos Clínicos Fase I como Asunto , Factor Estimulante de Colonias de Granulocitos y Macrófagos/efectos adversos , Factor Estimulante de Colonias de Granulocitos y Macrófagos/inmunología , Humanos , Melanoma/inmunología , Ratones , Sarcoma/inmunología , Transfección , Células Tumorales Cultivadas
6.
J Clin Endocrinol Metab ; 80(12): 3412-8, 1995 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8530574

RESUMEN

Chronic GnRH agonist therapy lowers androgens and decreases androgen-dependent hair shaft diameter, but the resulting induction of hypoestrogenemia has limited its usefulness as a single agent. Estrogen- and progestin-containing oral contraceptives also reduce circulating androgen levels and are commonly used empirically for the treatment of hirsutism, but have not been evaluated in a blinded randomized controlled fashion. The present study is the first double masked trial to evaluate the combination use of a GnRH agonist and an estrogen-containing oral contraceptive and tests our hypothesis that these could synergistically reduce androgen levels and suppress hormone-dependent hair growth while avoiding the symptoms and risks of agonist-induced hypoestrogenemia. We enrolled 64 women in a 24-week blinded randomized controlled trial to compare placebo, nafarelin (NAF; 400 micrograms, intranasal spray, twice daily), norethindrone (1 mg), and ethinyl estradiol (NOR 1/35; 0.035 mg, daily, for 3 of 4 weeks), or combined use of NAF and NOR 1/35 for 24 weeks. At baseline and every 8 weeks, we measured gonadotropins, estrogens, androgens, and hair growth. Bone density was assessed by dual energy x-ray adsorptiometry, and hot flashes were measured objectively. Baseline total testosterone (T), free T, percent free T, and sex hormone-binding globulin-binding capacity were similar among groups. With treatment, significant reductions (P = 0.01) in total T were seen with combination and NAF only therapy. Significant increases (P < 0.001) in the sex hormone-binding globulin-binding capacity were seen in women given NOR 1/35 alone or in combination with NAF. Free T levels decreased to approximately half of baseline levels with combination treatment (17.9 to 6.4 nmol/L; P < 0.001) and NOR 1/35 alone (20.8 to 10.2 nmol/L; P < 0.001). There was a significant decrease in hair shaft diameter after combination therapy (P < 0.05) that was not seen with either agent alone. Combination therapy also prevented the hot flashes and bone loss that occurred with agonist alone. In summary, our results demonstrate that combination GnRH agonist and low dose oral contraceptive therapy is more effective than either agent alone in the treatment of hirsutism and avoids the hypoestrogenic complications that occur with agonist only therapy.


Asunto(s)
Anticonceptivos Orales/administración & dosificación , Etinilestradiol/uso terapéutico , Hormona Liberadora de Gonadotropina/agonistas , Hirsutismo/tratamiento farmacológico , Nafarelina/uso terapéutico , Noretindrona/uso terapéutico , Adulto , Anticonceptivos Orales/uso terapéutico , Relación Dosis-Respuesta a Droga , Combinación de Medicamentos , Femenino , Cabello/efectos de los fármacos , Cabello/patología , Hirsutismo/patología , Humanos , Persona de Mediana Edad , Resultado del Tratamiento
7.
Obstet Gynecol ; 86(3): 386-8, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7651647

RESUMEN

OBJECTIVE: To compare the size of arterial vessels in myomas from women treated with GnRH agonist (GnRH-a) or given placebo. METHODS: Our study group included 46 women about to undergo myomectomy or hysterectomy; 30 were treated with leuprolide acetate (3.75 or 7.5 mg) in three monthly doses, and 16 were given placebo. Arterial diameters of the intramyomatous vessels were measured using an ocular micrometer on hematoxylin and eosin-stained slides. RESULTS: Clinically and radiologically, the uterine volume of GnRH-a-treated patients decreased by an average of 30%, and the diameter of the largest myoma decreased by 27%. The average diameter of intramyomatous arteries was 24% smaller in GnRH-a subjects compared with those receiving placebo (136 +/- 42 versus 178 +/- 60 microns, P < .01). In addition, arteriosclerotic changes, including intimal and medial fibrosis, were seen more often in the GnRH-a-treated subjects (48 versus 25%, P < .05). CONCLUSION: Intramyomatous arteries were smaller and more often showed arteriosclerotic changes in leiomyomas removed from women treated with GnRH-a compared with those given placebo. The estrogen deprivation induced by GnRH-a may cause a relative vasoconstriction of myomatous vessels. Whether this decreased vessel size is the principal contributor to decreased myoma size will require further study.


Asunto(s)
Leiomioma/tratamiento farmacológico , Leuprolida/uso terapéutico , Premedicación/métodos , Neoplasias Uterinas/tratamiento farmacológico , Útero/irrigación sanguínea , Adulto , Arterias/efectos de los fármacos , Arterias/patología , Terapia Combinada , Constricción Patológica/inducido químicamente , Método Doble Ciego , Femenino , Humanos , Histerectomía , Leiomioma/patología , Neoplasias Uterinas/patología
8.
Fertil Steril ; 58(2): 373-7, 1992 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1633905

RESUMEN

STUDY OBJECTIVE: To assess the predictive value of a single serum human chorionic gonadotropin (hCG) measurement obtained on day 14, 15, or 16 after transfer in in vitro fertilization or gamete intrafallopian transfer pregnancies. DESIGN: Retrospective. SETTING: Assisted reproductive technology (ART) programs. PATIENTS: One hundred thirty-four consecutive pregnancies from two ART programs were reviewed. RESULTS: The incidence of livebirth was only 6% when day 14 to 16 hCG values were less than 100 mIU/mL, but increased to 82% with levels greater than 100 mIU/mL (P less than 0.001). The incidence of livebirth and multiple birth correlated with rising hCG levels. Only 1% (1/71) of pregnancies with serum hCG values greater than 100 mIU/mL was ectopic, and this case was a bilateral (double) ectopic. CONCLUSIONS: A single serum hCG measurement obtained 14 to 16 days after embryo or gamete transfer not only is diagnostic but also has good predictive value for pregnancy outcome.


Asunto(s)
Gonadotropina Coriónica/sangre , Fertilización In Vitro , Transferencia Intrafalopiana del Gameto , Resultado del Embarazo , Femenino , Humanos , Embarazo , Estudios Retrospectivos , Factores de Tiempo
9.
J Orthop Res ; 10(6): 836-44, 1992 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1403298

RESUMEN

Bone remodeling is an expected sequela with total hip arthroplasty (THA). Although there are several methods of estimating bone response in THA patients from radiographs, there are no accurate and generally accepted methods for quantitative determinations in vivo. In this study, we describe an application of dual x-ray absorptiometry (DXA) for measuring bone mineral content and bone mineral density in the proximal femur following THA. DXA is a noninvasive technique with minimal radiation exposure (< 5 mrem). Various aspects of measurement error (accuracy and reliability) of this application of DXA were determined in a series of studies reported here. Accuracy error (how similar are the measured and actual values) was < 1% determined in bone phantoms of four densities. Precision error (how reproducible are the measurements) was also < 1% at all four densities in the phantoms and was only slightly elevated (0.9-1.5%) in repeated measurements of implanted cadaver femora. Precision error in vivo, determined both from multiple replicates on five patients and from duplicate scans on 30 patients, was further elevated but remained < 5%. Contributions to precision error, rotation of the leg, and interoperator variability were assessed; none was found to elevate precision error appreciably. We suggest that DXA is a feasible method for quantifying bone response following THA, and will allow discrimination of small changes (> 5%) not previously measurable.


Asunto(s)
Densidad Ósea , Articulación de la Cadera/diagnóstico por imagen , Prótesis de Cadera , Absorciometría de Fotón , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Remodelación Ósea , Fémur/diagnóstico por imagen , Humanos , Modelos Estructurales , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados
10.
J Orthop Res ; 12(5): 657-64, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7931782

RESUMEN

We examined bone-to-implant relative displacement of acetabular prostheses acutely and after ingrowth in a canine model. Uncemented hemispherical acetabular cups with titanium mesh pads comprising approximately 26% of the surface of the cup were inserted in eight adult canine hemipelves ex vivo. The acetabular prostheses were fixed with 13 mm titanium screws. Zero, one, and two-screw configurations were tested, with the order of testing randomly assigned. A load simulating 1,000 cycles of canine gait as applied to the acetabular component, and relative displacements were measured at three locations between implant and bone to determine acute fixation. A repeated measures analysis of variance showed that two screws produced only 42% of the average relative displacement of one screw and 14% that of zero screws. Eight adult mixed-breed dogs then underwent unilateral total hip arthroplasty. All acetabula were biologically fixed with two cancellous screws. The results at 4 months showed significantly less relative displacement between the implant and bone than was measured in ex vivo implantations (p = 0.014). Bone ingrowth filled 20 +/- 6% (mean +/- SD) of the available space. The relative displacements of these implants were small in all cases (12 +/- 13 microns) and did not correlate with the amount of bone ingrowth. These data suggest that acetabular fixation with two screws can lead to bone ingrowth and reduced relative motion of the prosthesis under functional loading.


Asunto(s)
Acetábulo/fisiología , Fijación de Fractura , Prótesis Articulares , Oseointegración/fisiología , Acetábulo/cirugía , Animales , Tornillos Óseos , Perros , Modelos Biológicos , Falla de Prótesis , Soporte de Peso/fisiología
11.
J Orthop Res ; 18(1): 56-63, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10716279

RESUMEN

This study used radiography, gait analysis, gluteal muscle mass, mechanical testing, and qualitative histology to compare three methods of gluteal muscle attachment to an allograft/endoprosthetic composite of the proximal 25% of the femur in an in vivo canine model. The three methods of gluteal muscle attachment were identical to those used clinically in human patients for hip revision and proximal femoral limb salvage: the host gluteal tendon sutured to the allograft tendon (tendon group), the host greater trochanter with intact gluteal tendons secured to the allograft with a cable-grip system (grip group), and periosteally vascularized proximal femoral bone onlay with intact tendons wrapped around the allograft (wrap group). On the basis of radiographs taken every 2 months, the tendon group had more graft fractures than did the grip or wrap group. Radiographic union of the graft-host bone junction occurred more rapidly and there was less graft resorption in the wrap group than in the other two groups. In all dogs, peak vertical ground-reaction forces in the treated limb decreased immediately after surgery and then slowly increased over the length of the study. The dogs in the wrap group regained normal weight-bearing on the treated limb more quickly than did those in the other groups. The constructs in the tendon group were weaker and less stiff immediately after surgery than were those in the other groups or in intact controls. Histologic analysis confirmed that the wrap technique resulted in complete union of the host bone-allograft junction more often than did the other techniques. The wrap method had the best functional outcome after 9 months when an allograft/endoprosthetic composite was used during total hip arthroplasty in this canine model.


Asunto(s)
Artroplastia de Reemplazo de Cadera/métodos , Fémur/trasplante , Animales , Perros , Músculos , Tendones/fisiología , Resistencia a la Tracción , Trasplante Homólogo
12.
J Orthop Res ; 19(2): 308-17, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11347706

RESUMEN

This study compared the effect of augmentation of allograft host bone junctions with recombinant human bone morphogenetic protein-2 (rhBMP-2) on an absorbable collagen sponge (ACS), autogenous cancellous bone graft (CBG), and a collagen sponge alone in a canine intercalary femoral defect model repaired with a frozen allograft. Outcome assessment included serial radiographs, dual energy X-ray absorptiometry scans, and gait analyses, and mechanical testing and histology of post-mortem specimens. The distal junction healed more quickly and completely with rhBMP-2 than ACS alone based on qualitative radiography and histologic evaluations. The primary tissue in the unhealed gaps in the ACS group was fibrous connective tissue. The proximal allograft host bone junction had complete bone union in the three treatment groups. There was significantly greater new bone callus formation at both junctions with rhBMP-2 than with CBG or ACS alone that resulted in increased bone density around the allograft host bone junctions. All dogs shifted their weight from the treated leg to the contralateral pelvic limb immediately after surgery. Weight bearing forces were redistributed equally between the pelvic limbs at 12 weeks after surgery with rhBMP-2, at 16 weeks after surgery with CBG, and at 24 weeks after surgery with ACS alone. Bending and compressive stiffnesses of the whole treated femora were equal to the contralateral control femora in all treatment groups, whereas torsional rigidities of the whole treated femora for the CBG and ACS groups were significantly less than the control. Both the proximal and distal junctions the treated with rhBMP-2 had torsional stiffnesses and strengths equal to intact control bones. Ultimate failure torques of the proximal junctions of the CBG group and of both junctions of the ACS group were significantly less than the BMP-treated bones. Augmentation of the allograft host bone junctions with rhBMP-2 on an ACS gave results for all parameters measured that equaled or exceeded autogenous graft in this canine intercalary femoral defect model.


Asunto(s)
Proteínas Morfogenéticas Óseas/uso terapéutico , Trasplante Óseo , Fémur/cirugía , Factor de Crecimiento Transformador beta , Animales , Fenómenos Biomecánicos , Densidad Ósea , Proteína Morfogenética Ósea 2 , Perros , Elasticidad , Femenino , Fémur/diagnóstico por imagen , Fémur/patología , Fémur/fisiopatología , Humanos , Radiografía , Proteínas Recombinantes , Resistencia a la Tracción , Trasplante Homólogo , Soporte de Peso
13.
J Orthop Res ; 19(2): 318-27, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11347707

RESUMEN

The purpose of this study was to determine the effect of recombinant human bone morphogenetic protein type 2 (rhBMP-2) on the histomorphometry of femoral allograft-host bone union and allograft remodeling. A 6 cm mid-diaphyseal femoral defect was created and filled with an allograft stabilized with an interlocking nail in 21 dogs. Dogs were randomly divided into three equal groups and the allograft-host bone junctions and the mid-diaphyses of the allografts were treated with either an absorbable collagen sponge (ACS) loaded with rhBMP-2 (BMP group), an autogenous cancellous bone graft (CBG group), or ACS loaded with buffer solution (ACS group). All dogs received daily tetracycline until sacrifice at 24 weeks to label new bone formation. Histomorphometric analyses on sections of proximal and distal allograft-host bone junctions and the mid-diaphyseal portion of allografts were performed using fluorescent and regular light microscopy. Analyses of the host bone and junctions between allograft and host bone revealed significantly greater new bone formation and larger osteon radii in the BMP group compared to CBG and ACS groups and contralateral intact bone. Porosity in CBG and ACS groups was significantly higher than in the BMP group, which had similar values to intact bone. In transverse sections of allografts, the largest pore diameters were present in the CBG group. Based on all parameters measured, significantly higher bone turnover occurred in the outer cortical area of the allograft in all groups as compared to the inner cortical and mid-cortical areas. New bone formation and osteon radius/osteon width in allografts were similar for all three groups. Higher porosity and larger pore diameters in the CBG and ACS groups suggested higher bone resorption versus formation in these groups compared to the BMP group. The results of this study reveal more balanced allograft bone resorption and bone formation in the BMP group, with greater resorptive activity in the CBG and ACS groups. However, neither rhBMP-2 nor autogenous bone graft increased allograft incorporation when compared to the negative control (ACS group).


Asunto(s)
Enfermedades Óseas/cirugía , Remodelación Ósea , Trasplante Óseo , Fémur/fisiopatología , Fémur/cirugía , Factor de Crecimiento Transformador beta , Implantes Absorbibles , Animales , Proteína Morfogenética Ósea 2 , Proteínas Morfogenéticas Óseas/uso terapéutico , Remodelación Ósea/efectos de los fármacos , Colágeno , Perros , Femenino , Fémur/efectos de los fármacos , Humanos , Poríferos , Proteínas Recombinantes , Trasplante Homólogo
14.
J Bone Joint Surg Am ; 76(2): 195-201, 1994 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8113253

RESUMEN

A study was begun in 1983 to determine the efficacy of a threaded acetabular cup. Fifty-five patients who had a total of sixty-eight threaded titanium cups had a complete clinical and radiographic evaluation yearly. Fifty-two of the arthroplasties had been primary and sixteen, revisions. The average duration of follow-up was six years (range, five to nine years). Seventeen cups had to be revised at an average of sixty-two months (range, twenty-seven to 108 months) after the index operation. Nine additional cups were loose and revision was pending at the most recent follow-up examination. Failure was defined as revision or pending revision. Thus, twenty-six (38 per cent) of the sixty-eight cups failed. Sixteen (31 per cent) of the fifty-two primary arthroplasties failed and ten of the sixteen revision arthroplasties failed. Radiographic changes that were evident in patients who had a failed cup consisted of superomedial migration of the cup with osteolysis in Zone 3, as classified by DeLee and Charnley. These radiographic changes preceded symptoms in most patients. Because of the high rate of failure of this acetabular component at six years, we believe that its use is not warranted.


Asunto(s)
Prótesis de Cadera/instrumentación , Reoperación/estadística & datos numéricos , Acetábulo , Adulto , Anciano , Femenino , Estudios de Seguimiento , Prótesis de Cadera/efectos adversos , Prótesis de Cadera/métodos , Humanos , Masculino , Persona de Mediana Edad , Osteólisis/clasificación , Osteólisis/diagnóstico por imagen , Osteólisis/patología , Diseño de Prótesis , Falla de Prótesis , Radiografía , Titanio
15.
J Bone Joint Surg Am ; 76(6): 839-47, 1994 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8200890

RESUMEN

Twenty-four matched pairs of fresh-frozen humeri from human cadavera were divided randomly into four groups, in order to determine the most biomechanically desirable construct for the prophylactic fixation of impending fractures of the distal third of the humerus. Group I comprised intact humeri and matched humeri in which a 50 per cent lateral, semicylindrical cortical defect of the distal third had been created, resulting in a reproducible model of an impending fracture due to a lytic defect involving 50 per cent cortical disruption at the distal end of the humeral medullary canal. In Group II, such a lateral defect was created in both the right and the left, matched humeri. Group III was composed of humeri in which the defect had been fixed prophylactically with a single plate and the contralateral humeri, which had been treated with double-plating. Group IV comprised specimens in which the defect had been fixed with double-plating as well as those fixed with Rush rods. The fixation of each specimen in Groups III and IV was supplemented with bone cement. Each specimen was tested in torsion to failure, and the resulting peak torque, torsional stiffness, and total energy absorbed were analyzed for each group. The Group-I specimens that had a defect had a significantly lower (p < 0.05) peak torque, torsional stiffness, and total energy absorbed than the intact specimens; all of the specimens with a defect failed at the defect, and all of the intact specimens failed proximally. In Group II, there was a high side-to-side association with respect to peak torque, torsional stiffness, and total energy absorbed.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Fracturas Espontáneas/prevención & control , Fracturas del Húmero/prevención & control , Fenómenos Biomecánicos , Cementos para Huesos , Clavos Ortopédicos , Placas Óseas , Fracturas Espontáneas/fisiopatología , Humanos , Fracturas del Húmero/fisiopatología , Técnicas In Vitro , Anomalía Torsional
16.
J Biomech ; 27(2): 137-44, 1994 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8132681

RESUMEN

Effects of canine hip replacement (with a porous-coated femoral component) on the material properties of surrounding cortical bone were evaluated. The hypotheses were: (1) after four months of implantation, mechanical properties of the cortex would change, and (2) a collared implant would be associated with smaller changes than a collarless design. Unilateral total hip arthroplasty was performed in 15 mixed-breed dogs. Nine received a collared and six received a collarless femoral component. Four months after implantation, longitudinal ultrasonic wave propagation velocities and bone mineral densities (from dual energy X-ray absorptiometry) were measured in harvested femora and used to calculate the axial elastic constitutive coefficients for the cortex surrounding the implants. Results showed no difference in bone elasticity or bone density between collared and collarless designs. Significant velocity decreases from control values (p < 0.0001) were noted in all implanted femora at four months. Bone mineral densities also displayed decreased values after four months of implantation (p < 0.0145). Elastic coefficients were consistently less after four months of implantation when compared to control values (p < 0.0001). This alteration in material properties would affect load transfer into the implanted femur via the increased disparity between implant and bone stiffnesses regardless of the component design. Significant differences in the elastic coefficients between implanted and control femora support hypothesis 1. However, no group differences were found between collared and collarless implantations; thus, the study does not support hypothesis 2.


Asunto(s)
Densidad Ósea , Fémur/fisiología , Prótesis de Cadera , Aleaciones/química , Animales , Perros , Elasticidad , Fémur/diagnóstico por imagen , Modelos Biológicos , Oseointegración , Diseño de Prótesis , Estrés Mecánico , Propiedades de Superficie , Factores de Tiempo , Titanio/química , Ultrasonografía
17.
Orthop Clin North Am ; 31(4): 661-73, ix, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11043104

RESUMEN

Metastases to soft tissue are rare clinical problems. Most metastases are caused by carcinomatous deposits in the skeletal muscle, with lung carcinoma being the most common primary cause. Pain is more commonly observed in association with metastatic soft tissue masses than for soft tissue sarcomas. Treatment should be individualized, but for most carcinomas, initial radiotherapy treatment is recommended. Prognosis varies with the underlying disease, but for the typical patient with a metastatic carcinoma, mean survival duration is approximately 6 months.


Asunto(s)
Neoplasias de los Tejidos Blandos/secundario , Neoplasias de los Tejidos Blandos/terapia , Diagnóstico Diferencial , Humanos , Prevalencia , Pronóstico , Neoplasias de los Tejidos Blandos/diagnóstico , Neoplasias de los Tejidos Blandos/epidemiología
18.
Foot Ankle Int ; 20(5): 337-9, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10353775

RESUMEN

A case involving an isolated bony avulsion fracture of the extensor insertion on the distal phalanx of the great toe is described. The fracture was displaced 2 mm with 30 degrees dorsal angulation; the joint was congruent and not subluxed. The patient was treated nonsurgically with a rigid-soled sandal. Bony healing at the fracture site was clearly evident at 16 weeks postinjury. The patient began using a normal shoe at 10 weeks and resumed his running activities without pain at 16 weeks. The nonsurgical treatment of this injury, similar to that of a mallet finger, was successful.


Asunto(s)
Huesos del Pie/lesiones , Fracturas Óseas/fisiopatología , Hallux/lesiones , Adulto , Fracturas Óseas/terapia , Humanos , Masculino
19.
Am J Orthop (Belle Mead NJ) ; 29(4): 308-11, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10784020

RESUMEN

We present a case report of fat embolism syndrome (FES) that resulted in prolonged coma after cemented hemiarthroplasty in a patient with metastatic breast cancer. After the cemented hip prosthesis was placed, the patient developed decreased sensorium that progressed to coma in association with hypoxemia and tachypnea. Pulmonary compromise was mild, and the patient required only supplemental oxygen for support. The patient demonstrated no petechiae. Magnetic imaging results were consistent with FES. While the pulmonary symptoms resolved quickly, the patient remained unresponsive for 11 days without purposeful motor function. After waking she recovered rapidly, and at her 2-month follow-up appointment, demonstrated no adverse orthopedic, pulmonary, or neurologic sequelae.


Asunto(s)
Artroplastia de Reemplazo de Cadera , Coma/etiología , Embolia Grasa/complicaciones , Neoplasias Femorales/cirugía , Complicaciones Posoperatorias , Anciano , Neoplasias de la Mama/patología , Femenino , Neoplasias Femorales/complicaciones , Neoplasias Femorales/secundario , Fracturas de Cadera/etiología , Humanos
20.
Orv Hetil ; 138(37): 2349-54, 1997 Sep 14.
Artículo en Húngaro | MEDLINE | ID: mdl-9340583

RESUMEN

Prosthesis implantation in malignant oesophageal stenosis, postoperative gastric outlet obstruction and jejunal stenosis is a quick and efficient method. The expansile metal stents are a new alternative to conventional plastic prosthesis. The Wallstent is made of surgical steel alloy elements braided in tubular fashion. The Wallstent is delivered in a small diameter device, but it expands to a much larger size after placement than the inner diameter of plastic stent. The small predilatations diameter makes implantation of the Wallstent less prone to cause complications or severe discomfort to the patient. The authors implanted seven Wallstents in six patients. One patient had oesophageal cancer, one ischaemic jejunal stenosis and four jejunal stenosis due to extraluminal tumour recurrences following total gastrectomy for cancer. The authors discuss in detail the usefulness of the Wallstent implantation in two cases with malignant disease of the oesophagus and jejunum. They remained symptoms free for 7 and 10 months after Wallstent implantation until death. Despite their higher initial cost, the metal stents are cost effective because of the absence of early and severe complications and the decrease in the hospitalization.


Asunto(s)
Neoplasias Esofágicas/cirugía , Stents , Neoplasias Gástricas/cirugía , Anciano , Cardias/patología , Constricción Patológica/diagnóstico por imagen , Constricción Patológica/patología , Constricción Patológica/cirugía , Neoplasias Esofágicas/diagnóstico por imagen , Neoplasias Esofágicas/patología , Humanos , Masculino , Metales , Persona de Mediana Edad , Radiografía , Neoplasias Gástricas/diagnóstico por imagen , Neoplasias Gástricas/patología
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