RESUMEN
STUDY DESIGN: A retrospective review of 317 patients to determine the efficacy of allogeneic fibula arthrodesis after anterior cervical discectomy. OBJECTIVE: To examine the efficacy of allogeneic fibula as an alternative fusion substrate after anterior cervical discectomy, and to determine the effects of cigarette smoking on the healing of fibula allografts. SUMMARY OF BACKGROUND DATA: The use of autogeneic iliac crest is associated with graft harvest complications in up to 20% of patients. Most studies reporting on the use of allogeneic iliac crest cite a high collapse rate. Few studies exist that note the efficacy of allogeneic fibula in this procedure and the effects of cigarette smoking on fusion rate. METHODS: From 1988 to 1993, 317 patients underwent grafting by the Smith-Robinson technique with allogeneic fibula after anterior cervical discectomy. Patients who described themselves as habitual cigarette smokers or who smoked during the perioperative or postoperative period were categorized as smokers. All patients were immobilized in a rigid cervical orthosis (Philadelphia collar) for at least 10 weeks postoperatively. RESULTS: A minimum of 2 years follow-up was achieved in 289 patients. In all, 162 men and 127 women had a total of 311 levels grafted, and the mean follow-up period was 33 months (range, 24 to 51 months). Of patients who received allogeneic fibula at one level, 90% (242/269) achieved radiologic fusion. The fusion rate was 92% (182/198) among nonsmokers compared with 85% (60/71) among smokers (not a statistically significant difference; P = 0.120). After two-level procedures, 72% (13/18) of the patients showed fusion. The fusion rate was 50% (2/4) among smokers compared with 79% (11/14) among nonsmokers (P = 0.53). When one-level arthrodesis (90%) was compared with two-level arthrodesis (72%), the difference approached statistical significance (P = 0.054). Neither of the two patients, both nonsmokers, who received grafts at three levels achieved fusion. There were no infections, and no grafts collapsed. Two grafts extruded (0.6%), but these were partial and did not require reoperation. Both patients fused and constituted the only patients with more than 10 degrees of angulation in the series. Graft subsidence occurred in 5% (17/311) of the grafts, mostly in the beginning of the series, and was not problematic. This phenomenon was thought to have been caused by overaggressive removal of the cortical endplate. CONCLUSION: Allogeneic fibula is an effective substrate for use in achieving fusion after anterior cervical discectomy. Maximal results are achieved with its use at one level in nonsmokers. Cigarette smoking decreased the fusion rate with allogeneic fibula in the anterior cervical spine, but not by a statistically significant amount.
Asunto(s)
Vértebras Cervicales/cirugía , Discectomía , Peroné/trasplante , Enfermedades de la Columna Vertebral/cirugía , Fusión Vertebral/métodos , Vértebras Cervicales/patología , Femenino , Estudios de Seguimiento , Liofilización , Humanos , Masculino , Estudios Retrospectivos , Fumar/efectos adversos , Enfermedades de la Columna Vertebral/patología , Trasplante Homólogo , Cicatrización de HeridasRESUMEN
BACKGROUND: Fluoroscopy, cost, and patient transport contribute to difficulties occasionally associated with the placement of vena caval filters. Follow-up data in the literature document the use of duplex ultrasonography in visualizing the filter and determining caval patency. Filter placement at the bedside or in the vascular laboratory with duplex ultrasonography may simplify this common procedure. We have attempted to define the feasibility of this method. METHODS: Patients referred to the vascular surgery service for vena caval interruption were evaluated for ability to visualize the renal veins and inferior vena cava. Location of renal veins, maximum diameter of the vena cava, and presence or absence of thrombus were documented. If visualization was adequate, placement was performed at the bedside for patients in intensive care or in the vascular laboratory for nonmonitored patients. The initial 10 patients and subsequent patients in whom there was a question of adequate deployment underwent completion abdominal roentgenography. Patient follow-up was difficult. Duplex ultrasonography was used to assess migration, thrombus adherent to the filter, and vena caval patency. Patients in whom filter placement was prophylactic were given anticoagulants at the discretion of the primary physician. Inadequate visualization or vena caval size greater than 28 mm prompted fluoroscopic placement of the vena caval filter, because only Greenfield titanium filters were used in the study. RESULTS: Twenty-nine patients were referred for vena caval interruption. Inadequate visualization occurred in four obese patients, and filters were placed by fluoroscopy. There were no vena caval measurements greater than 24 mm. Twenty-five filters were placed without technical difficulty. One filter tilted into the right renal vein, requiring a suprarenal filter placed by fluoroscopy. Patient retrieval for follow-up has been difficult, but by ultrasonography there has been one vena caval thrombosis and no major filter migration. There have been no reported pulmonary emboli other than the one patient with initial tilt of the filter. CONCLUSIONS: Placement of vena caval filters is feasible with duplex ultrasonography. Visualization is the only limiting condition to placement and occurs rarely. Reducing the need for fluoroscopy, lowering costs, and not needing to transport the critically ill patient support the use of this system. Intravascular ultrasonography in selected patients may eliminate the need for fluoroscopic placement of vena caval filters.
Asunto(s)
Venas Renales/diagnóstico por imagen , Tromboflebitis/cirugía , Ultrasonografía Doppler Dúplex/métodos , Filtros de Vena Cava , Vena Cava Inferior/diagnóstico por imagen , Fluoroscopía , Humanos , Monitoreo Intraoperatorio/métodos , Arteria Renal/diagnóstico por imagen , Tromboflebitis/diagnóstico por imagenRESUMEN
Expression of the vascular permeability factor/vascular endothelial growth factor (VEGPF) gene was investigated in human central nervous system (CNS) neoplasms and normal brain. Adsorption of capillary permeability activity from human glioblastoma multiforme (GBM) cell conditioned medium and GBM cyst fluids by anti-VEGPF antibodies demonstrated that VEGPF is secreted by GBM cells and is present in sufficient quantities in vivo to induce vascular permeability. Cloning and sequencing of polymerase chain reaction-amplified GBM and normal brain cDNA demonstrated three forms of the VEGPF coding region (567, 495, and 363 nucleotides), corresponding to mature polypeptides of 189, 165, and 121 amino acids, respectively. VEGPF mRNA levels in CNS tumors vs. normal brain were investigated by the RNase protection assay. Significant elevation of VEGPF gene expression was observed in 81% (22/27) of the highly vascular and edema-associated CNS neoplasms (6/8 GBM, 8/8 capillary hemangioblastomas, 6/7 meningiomas, and 2/4 cerebral metastases). In contrast, only 13% (2/15) of those CNS tumors that are not commonly associated with significant neovascularity or cerebral edema (2/10 pituitary adenomas and 0/5 nonastrocytic gliomas) had significantly increased levels of VEGPF mRNA. The relative abundance of the forms of VEGPF mRNA was consistent in tumor and normal brain: VEGPF495 > VEGPF363 > VEGPF567. In situ hybridization confirmed the presence of VEGPF mRNA in tumor cells and its increased abundance in capillary hemangioblastomas. Our results suggest a significant role for VEGPF in the development of CNS tumor neovascularity and peritumoral edema.
Asunto(s)
Neoplasias Encefálicas/genética , Encéfalo/metabolismo , Neoplasias del Sistema Nervioso Central/genética , Factores de Crecimiento Endotelial/análisis , Factores de Crecimiento Endotelial/genética , Linfocinas/análisis , Linfocinas/genética , ARN Mensajero/metabolismo , Secuencia de Bases , Southern Blotting , Encéfalo/patología , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/secundario , Neoplasias del Sistema Nervioso Central/metabolismo , Neoplasias del Sistema Nervioso Central/patología , ADN de Neoplasias/análisis , ADN de Neoplasias/genética , Epilepsia/genética , Epilepsia/metabolismo , Epilepsia/patología , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patología , Hemangiosarcoma/genética , Hemangiosarcoma/metabolismo , Hemangiosarcoma/patología , Humanos , Neoplasias Meníngeas/genética , Neoplasias Meníngeas/metabolismo , Neoplasias Meníngeas/patología , Meningioma/genética , Meningioma/metabolismo , Meningioma/patología , Datos de Secuencia Molecular , Oligodesoxirribonucleótidos , Sondas de Oligonucleótidos , ARN Mensajero/análisis , ARN Mensajero/genética , Mapeo Restrictivo , Factor A de Crecimiento Endotelial Vascular , Factores de Crecimiento Endotelial VascularRESUMEN
Glioblastoma multiforme, the most common and most lethal primary central nervous system neoplasm, is noted for its phenotypic and biological heterogeneity. This heterogeneity may result from genetic alterations accumulated by a single transformed astrocyte as it evolves into a monoclonal tumor. Alternatively, it may be attributed to the presence of multiple biologically and genetically distinct astrocytic populations within a polyclonal tumor. To address the issue of clonal composition of glioblastoma multiforme the authors used two independent approaches: analysis of X-chromosome inactivation and analysis of chromosomes 10 and 17 for tumor-specific somatic deletions. The analysis included 10 tumors from nine female patients with glioblastoma multiforme (eight primary and two recurrent tumors), who were heterozygous at either of two X-chromosome genes (hypoxanthine phosphoribosyl-transferase or phosphoglycerate kinase). Nine glioblastomas multiforme demonstrated a monoclonal pattern on X-chromosome analysis; contamination with normal tissue obscured the analysis in one tumor. Somatic deletions on chromosomes 10 and/or 17 occurred in nine tumors, supporting a monoclonal composition for these tumors. These data suggest that glioblastoma multiforme is a monoclonal neoplasm, derived from the clonal expansion of a single transformed astrocyte that has, as a fundamental step in tumorigenesis, sustained a critical genetic alteration on chromosome 10 and/or 17.
Asunto(s)
Neoplasias Encefálicas/genética , Glioblastoma/genética , Hipoxantina Fosforribosiltransferasa/genética , Fosfoglicerato Quinasa/genética , Polimorfismo Genético/genética , Neoplasias Encefálicas/enzimología , Neoplasias Encefálicas/patología , Deleción Cromosómica , Mapeo Cromosómico , Cromosomas Humanos Par 10 , Cromosomas Humanos Par 17 , Células Clonales , ADN de Neoplasias/genética , Compensación de Dosificación (Genética) , Femenino , Glioblastoma/enzimología , Glioblastoma/patología , Heterocigoto , Humanos , Linfocitos/fisiología , Hibridación de Ácido NucleicoRESUMEN
The synthesis and secretion of anterior pituitary hormones are subjected to a variety of positive and negative feedback mechanisms. Aberrancies of these highly regulated phenomena may lead to hyperplasia involving multiple cells of the anterior lobe. Alternatively, a rare genetic mutation in a single cell may precede its clonal expansion. Which of these mechanisms is operative in the development of corticotroph adenomas is not known. To examine this question, we studied the clonal composition of ACTH-producing pituitary adenomas from female patients with Cushing's disease by using X-chromosome inactivation analysis. Nine of 27 patients examined were heterozygous at 1 of the 2 X-chromosome-linked polymorphic loci, hypoxanthine-phosphoribosyl-transferase and phosphoglycerate-kinase. The methylation patterns of the hypoxanthine-phosphoribosyl-transferase and phosphoglycerate-kinase genes, distinguishing between the active and inactive alleles, were analyzed in DNA extracted from the central part of the tumor and compared with those of autologous lymphocyte DNA. Six tumors (4 microadenomas and 2 macroadenomas) showed a single active allele of the X-chromosome-linked genes and were monoclonal in nature. The other 3 pituitary adenomas (1 microadenoma and 2 macroadenomas, 1 from a patient with Nelson's syndrome) revealed a polyclonal pattern of X-chromosome inactivation. Our data demonstrate that corticotroph adenomas of the pituitary may arise from a single cell or from more than one cell. Whether fundamentally different endocrine mechanisms underlie the two processes remains to be seen.
Asunto(s)
Adenoma/patología , Síndrome de Cushing/patología , Neoplasias Hipofisarias/patología , Polimorfismo de Longitud del Fragmento de Restricción , Cromosoma X , Adenoma/química , Adenoma/genética , Alelos , Antígenos CD/análisis , Células Clonales , ADN , Femenino , Heterocigoto , Humanos , Hipoxantina Fosforribosiltransferasa/genética , Fosfoglicerato Quinasa/genética , Hormonas Hipofisarias/análisis , Neoplasias Hipofisarias/química , Neoplasias Hipofisarias/genética , Coloración y EtiquetadoRESUMEN
Complement-derived peptides capable of activating neutrophils appear in plasma during flares of systemic lupus erythematosus (SLE). One possible consequence of such activation is an increased expression of the surface adhesion promoting heterodimer gp165/95 (the complement receptor CR3). The quantity of gp165/95 was measured by indirect immunofluorescence using a monoclonal antibody of the CD11b group. Mol, directed to the alpha chain. Eighty-three percent of 26 patients with SLE expressed gp165/95 on their neutrophil surface to a greater extent than normals. The highest levels of surface gp165/95 were found in patients with the most severe disease, who also had the highest levels of the circulating anaphylatoxin C3a (mean = 560 ng/ml versus 147 ng/ml in controls). There was a negative correlation between expression of gp165/95 and absolute neutrophil count. Five individuals followed serially demonstrated an increase in surface gp165/95 during disease flares which returned to normal with clinical improvement. These data support the hypothesis that the neutrophils of patients with active SLE recruit increased numbers of gp165/95 molecules to their surface in respose to complement activation; these activated neutrophils bearing increased numbers of adhesion promoting gp165/95 may contribute to endothelial injury in SLE.
Asunto(s)
Complemento C3a/análogos & derivados , Lupus Eritematoso Sistémico/inmunología , Neutrófilos/análisis , Receptores de Complemento/análisis , Anticuerpos Monoclonales/inmunología , Complemento C3/análogos & derivados , Complemento C3/análisis , Humanos , Receptores de Complemento 3bRESUMEN
Study of the chyme composition in different phases of digestion at different levels of the small intestine showed the composition to be stabilized enough in respect to the water and electrolytes contents as well as the main nutricious substances. Gradual increase in concentration of the main NSs occurs in the advancing chyme. The data obtained suggest that the constancy of the chyme composition is only valid in respect to the water and electrolytes regardless of their unequal contents in the food.
Asunto(s)
Digestión , Intestino Delgado/análisis , Animales , Perros , Duodeno/análisis , Femenino , Homeostasis , Absorción Intestinal , Yeyuno/análisis , Masculino , Estómago/análisis , Factores de TiempoRESUMEN
A device is described which can be attached to all blood bags. Two of these devices are heat-sealed together aseptically at any time during the storage life of the blood unit, and an opening connecting the two is created. In vitro and in vivo studies show that ten passes of a unit of blood through these devices produces no cytological changes and does not alter the in vivo survival of the unit when transfused. Further, if the unit is frozen, then thawed, and even stored at 4 C for five days after thawing, the in vivo survival is still unaffected.
Asunto(s)
Bancos de Sangre , Recolección de Muestras de Sangre/instrumentación , Esterilización , Conservación de la Sangre , Envejecimiento Eritrocítico , Calor , HumanosAsunto(s)
Amoníaco/farmacología , Hipercapnia/metabolismo , Hipoxia/metabolismo , Respiración/efectos de los fármacos , Aminoácidos/líquido cefalorraquídeo , Amoníaco/líquido cefalorraquídeo , Animales , Encéfalo/metabolismo , Dióxido de Carbono/sangre , Perros , Oxígeno/sangre , Ácidos Tricarboxílicos/líquido cefalorraquídeoRESUMEN
This study was designed to determine blood flow to the liver during hypercapnia and combined hypercapnia-hypoxia with the portal vein and hepatic artery intact except for placement of an electromagnetic flow probe around these vessels. Twenty mongrel dogs weighing 30-45 kg were anesthetized with pentobarbital and flow probes and occluders were surgically implanted. Ten of these dogs were subjected to hypercapnia alone. During inspiration of 6% CO2 in room air, portal vein flow increased from 588 +/- 73 ml/min to 731 +/- 113 ml/min (p less than .05), while hepatic artery flow did not change significantly from its control mean of 221 +/- 38 ml/min. In the remaining dogs, inhalation of 6% O2 resulted in a reduction of portal blood flow within 30 min from 527 +/- 55 ml/min to 381 +/- 41 ml/min (p less than .01). Again, mean hepatic artery flow did not increase significantly above its control of 273 +/- 43 ml/min. Subsequent inhalation of 6% CO2 plus 6% O2 (combined hypercapniahypoxia) for 30 min in these same animals resulted in a significant increase of portal vein blood flow from 514 +/- 46 ml/min to 716 +/- 116 ml/min (p less than .05). Thus, hypercapnia alone increases total liver blood flow, primarily by an increase in portal vein flow. Hypoxia results in a decrease in portal vein flow. The superimposition of hypercapnia on hypoxia restores blood flow to a level close to that found with hypercapnia alone. Hypercapnia in the range of 63 +/- 4 mmHg PCO2 overwhelms the tendency toward a reduction of portal vein blood flow induced by an arterial PO2 of 42 +/- 5 mmHg in the presence of mild hypocapnia (PCO2 : 30.2 +/- 1 mmHg).
Asunto(s)
Hipercapnia/fisiopatología , Hipoxia/fisiopatología , Circulación Hepática , Animales , Perros , Arterias Mesentéricas/fisiopatología , Sistema Porta/fisiopatologíaRESUMEN
Participation of the small intestine in the intermediate carbohydrate metabolism was pointed out by appearing of glucose in the small intestine secret within 2-3 hrs after carbohydrate uptake in the concentration comparable or even exceeding that in the blood. The glucose concentration in the blood drops just when it increases in the intestinal juice, while increase in the blood sugar coincided with reducing of the glucose concentration in the small intestine secret. This suggests that the small intestine lumen can serve as one of the depots for carbohydrates: a kind of temporary depot for monomeres.
Asunto(s)
Metabolismo de los Hidratos de Carbono , Intestino Delgado/metabolismo , Animales , Glucemia/metabolismo , Dieta , Perros , Ayuno , Glucosa/metabolismo , Mucosa Intestinal/metabolismo , Factores de TiempoRESUMEN
Differential light-scattering measurements of Staphylococcus aureus cultures were made before and after treatment with streptomycin. Changes were observed in the light-scattering characteristics of streptomycin-treated sensitive cells within 5 min after suspension in a hypotonic solution. No changes were observed with a resistant strain of cells nor with either strain in an isotonic solution. The observed effects occur more slowly when the cells are growing slowly. The physical effects consonant with the changes in the light-scattering curves are a broadening of the cell size distribution, a slight reduction in mean size, and the appearance of clumps or debris. We conclude that streptomycin rapidly alters the selective permeability of the cell membrane and makes the cells susceptible to increased osmotic stresses.
Asunto(s)
Fragilidad Osmótica , Staphylococcus/efectos de los fármacos , Estreptomicina/farmacología , Permeabilidad de la Membrana Celular/efectos de los fármacos , Medios de Cultivo , Farmacorresistencia Microbiana , Soluciones Hipotónicas , Soluciones Isotónicas , Rayos Láser , Dispersión de Radiación , Staphylococcus/citología , Staphylococcus/crecimiento & desarrollo , Factores de TiempoRESUMEN
Effects of heat on diameter, size distribution, and refractive index of Staphylococcus epidermidis suspensions were determined accurately by computer analysis of differential light scattering data.