RESUMEN
AIMS: Lumbar fusion is known to reduce the variation in pelvic tilt between standing and sitting. A flexible lumbo-pelvic unit increases the stability of total hip arthroplasty (THA) when seated by increasing anterior clearance and acetabular anteversion, thereby preventing impingement of the prosthesis. Lumbar fusion may eliminate this protective pelvic movement. The effect of lumbar fusion on the stability of total hip arthroplasty has not previously been investigated. PATIENTS AND METHODS: The Medicare database was searched for patients who had undergone THA and spinal fusion between 2005 and 2012. PearlDiver software was used to query the database by the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) procedural code for primary THA and lumbar spinal fusion. Patients who had undergone both lumbar fusion and THA were then divided into three groups: 1 to 2 levels, 3 to 7 levels and 8+ levels of fusion. The rate of dislocation in each group was established using ICD-9-CM codes. Patients who underwent THA without spinal fusion were used as a control group. Statistical significant difference between groups was tested using the chi-squared test, and significance set at p < 0.05. RESULTS: At one-year follow-up, 14 747 patients were found to have had a THA after lumbar spinal fusion (12 079 1 to 2 levels, 2594 3 to 7 levels, 74 8+ levels). The control group consisted of 839 004 patients. The dislocation rate in the control group was 1.55%. A higher rate of dislocation was found in patients with a spinal fusion of 1 to 2 levels (2.96%, p < 0.0001) and 3 to 7 levels (4.12%, p < 0.0001). Patients with 3 to 7 levels of fusion had a higher rate of dislocation than patients with 1 to 2 levels of fusion (odds ratio (OR) = 1.60, p < 0.0001). When groups were matched for age and gender to the unfused cohort, patients with 1 to 2 levels of fusion had an OR of 1.93 (95% confidence interval (CI) 1.42 to 2.32, p < 0.001), and those with 3 to 7 levels of fusion an OR of 2.77 (CI 2.04 to 4.80, p < 0.001) for dislocation. CONCLUSION: Patients with a previous history of lumbar spinal fusion have a significantly higher rate of dislocation of their THA than age- and gender-matched patients without a lumbar spinal fusion. Cite this article: Bone Joint J 2017;99-B:585-91.
Asunto(s)
Artroplastia de Reemplazo de Cadera/efectos adversos , Luxación de la Cadera/etiología , Fusión Vertebral/efectos adversos , Anciano , Anciano de 80 o más Años , Bases de Datos Factuales , Femenino , Luxación de la Cadera/epidemiología , Articulación de la Cadera/diagnóstico por imagen , Prótesis de Cadera/efectos adversos , Humanos , Vértebras Lumbares/cirugía , Masculino , Persona de Mediana Edad , Postura , Falla de Prótesis , Radiografía , Estudios Retrospectivos , Medición de Riesgo/métodos , Fusión Vertebral/métodos , Estados Unidos/epidemiologíaRESUMEN
The fate of 2,4-dichlorophenoxyacetic acid (2,4-D) applied foliarly as the 2-ethylhexyl ester (EHE) to wheat and potatoes, to the soil as the dimethylamine (DMA) salt under apple tree canopies, and preplant as the free acid for wheat, lettuce, and radish was studied to evaluate metabolic pathways. Crop fractions analyzed for (14)C residues included wheat forage, straw, and grain; potato vine and tubers; and apple fruit. The primary metabolic pathway for foliar application in wheat is ester hydrolysis followed by the formation of base-labile 2,4-D conjugates. A less significant pathway for 2,4-D in wheat was ring hydroxylation to give NIH-shift products 2,5-dichloro-4-hydroxyphenoxyacetic acid (4-OH-2,5-D), 4-OH-2,3-D, and 5-OH-2,4-D both free and as acid-labile conjugates. The primary metabolic pathway in potato was again ester hydrolysis. 2,4-D acid was further transformed to 4-chlorophenoxyacetic acid and 4-OH-2,5-D. For the soil applications, (14)C residues in the crops were low, and characterization of the (14)C residues indicated association with or incorporation into the biochemical matrix of the tissue. The degradative pathways observed in wheat are similar to those characterized in other intact plant studies but differ from those in studies in wheat cell suspension culture in that no amino acid conjugates were observed.
Asunto(s)
Ácido 2,4-Diclorofenoxiacético/administración & dosificación , Ácido 2,4-Diclorofenoxiacético/metabolismo , Frutas/metabolismo , Herbicidas/metabolismo , Triticum/metabolismo , Verduras/metabolismo , Biodegradación Ambiental , Radioisótopos de Carbono , Hojas de la Planta , Suelo , Solanum tuberosum/metabolismoRESUMEN
2,4-Dichlorophenoxyacetic acid (2,4-D) labeled with (14)C was found to be rapidly eliminated by laying hens and lactating goats dosed orally for 7 consecutive days at 18 mg/kg of food intake and for 3 consecutive days at 483 mg/kg of food intake, respectively. Excreta of hens and goats contained >90% of the total dose within 24 h after the final dose. Tissue residues were low and accounted for <0.1% of the dose in these animals. For hens, the residues in muscle, liver, and eggs (0.006-0.030 ppm) were lower than those found in fat and kidney (0.028-0.714 ppm), 2,4-D equivalents. The tissue with highest residue in goat was the kidney at 1.44 ppm, 2,4-D equivalents. Milk, liver, composite fat, and composite muscle had significantly lower residue levels of 0.202, 0.224, 0.088, and 0.037 ppm, respectively. The most abundant tissue residue was 2,4-D and acid/base releasable residues of 2,4-D. A minor metabolite was identified as 2,4-dichlorophenol.
Asunto(s)
Ácido 2,4-Diclorofenoxiacético/farmacocinética , Pollos/metabolismo , Cabras/metabolismo , Lactancia , Tejido Adiposo/química , Animales , Radioisótopos de Carbono , Cromatografía Líquida de Alta Presión , Heces/química , Femenino , Riñón/química , Hígado/química , Espectrometría de Masas , Leche/química , Músculos/química , Residuos de Plaguicidas/análisisRESUMEN
Besides genistein and daidzein, which are active inducers of the nodYABCSUIJ operon in Bradyrhizobium japonicum, soybean seeds also excrete compounds that are not inducers of the nodYABCSUIJ genes but enhance induction of this operon in the presence of a suboptimal genistein concentration. This synergism was studied in detail, and specific compounds were identified in seed exudate which specifically induce the nodD1 gene but not the nodYABCSUIJ operon. Therefore, our current hypothesis is that the observed synergism is caused by a specific induction of nodD1. The specific nodD1 inducers from soybean seed extract have been purified and characterized chemically. They appear to be derivatives of genistein, glycitein, and daidzein with glucose, malonyl, and acetyl groups attached. Both root and seed exudate appear to contain these compounds, with the seed being the major source. No hydrolysis of these compounds to their aglycone forms was detected in the presence of B. japonicum. A model for nod gene induction in B. japonicum is discussed.
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Proteínas Bacterianas/genética , Flavonoides/fisiología , Regulación Bacteriana de la Expresión Génica , Operón , Rhizobiaceae/genética , Cromatografía Líquida de Alta Presión , Flavonoides/aislamiento & purificación , Genisteína , Hidrólisis , Isoflavonas/farmacología , Espectroscopía de Resonancia Magnética , Modelos Genéticos , Glycine max/química , Espectrometría de Masa Bombardeada por Átomos Veloces , Espectrofotometría Ultravioleta , Activación Transcripcional , beta-Galactosidasa/metabolismoRESUMEN
Evidence for the anomeric configurations and attachment sites of 3-deoxy-D-lyxo-2-heptulosaric acid (DHA) and apiosyl residues has been obtained through the characterization of two oligoglycosyl fragments isolated from rhamnogalacturonan II (RG-II). One of the oligoglycosyl fragments, a pentaglycosyl aldonic acid generated by Smith degradation of RG-II, was composed of four D-galactopyranosyluronic acid residues, a DHA residue, and a threonic acid residue (derived from a D-galactopyranosyluronic acid residue). The structural analysis of the pentaglycosyl aldonic acid established the beta-D-configuration for the DHA residue. Furthermore, it established that a previously identified diglycosyl side chain, 5-O-(beta-L-arabinofuranosyl)-DHA was directly attached to O-3 of a D-galactopyranosyluronic acid residue in the backbone of RG-II. The second oligoglycosyl fragment, a peralkylated diglycosyl hex-1-enitol, was generated by hex-5-enose degradation of permethylated and carboxyl-reduced RG-II. The structure of the peralkylated diglycosyl hex-1-enitol, beta-L-Rhap-(1----3')-beta-D-Apif-(1----5)-hex-1-enitol++ +, was determined by a combination of glycosyl-linkage composition analysis and n.m.r. spectroscopy. The n.m.r. data indicated the beta-configuration for the D-apiosyl residue. The isolation and characterization of the diglycosyl hex-1-enitol also established that a previously identified heptaglycosyl side chain was directly attached to O-2 of a D-galactopyranosyluronic acid in the backbone of RG-II.
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Pared Celular/química , Desoxiazúcares/metabolismo , Mananos/metabolismo , Oligosacáridos/química , Pectinas/metabolismo , Árboles/química , Butiratos/química , Secuencia de Carbohidratos , Células Cultivadas , Desoxiazúcares/química , Glucósidos/química , Mananos/química , Datos de Secuencia Molecular , Pectinas/química , Pentosas/química , Azúcares Ácidos/química , Alcoholes del Azúcar/químicaRESUMEN
Pneumocystis carinii cysts are capable of resisting host defenses and antimicrobial drugs and are therefore thought to be responsible for relapses of P. carinii pneumonia in AIDS and other immunocompromised patients. The interaction of P. carinii with its host, and other P. carinii, might be mediated by molecules which form the outer surfaces of this organism. Carbohydrates are known to play many roles in cell-cell adhesion, and have been detected on the surface of P. carinii by lectin labeling experiments. In this study P. carinii cyst wall material was obtained from Zymolyase treatment. Alditol acetate derivatives of neutral and amino sugars or trimethylsilyl derivatives of methyl glycosides were prepared from the monosaccharides released from the sample by acid hydrolysis. Analyses were done by a combination of gas chromatography and mass spectrometry. Glucose was found to be the major sugar constituent. Mannose and galactose were present in equal ratios. A lesser amount of N-acetyl-D-glucosamine, and trace amounts of ribose and sialic acid were present in the cyst wall samples analyzed. These sugars may mediate P. carinii-host interaction and play an important protective role by creating a permeability barrier around the cyst.
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Carbohidratos/análisis , Pneumocystis/análisis , Acetatos/química , Carbohidratos/química , Pared Celular/química , Cromatografía de Gases , Cromatografía de Gases y Espectrometría de Masas , Polisacáridos/química , Esporas Fúngicas/análisis , Alcoholes del Azúcar/química , Compuestos de Trimetilsililo/químicaRESUMEN
Lipid A's from two Bradyrhizobium species and from the phylogenetically closely related species "Pseudomonas carboxydovorans" were found to contain 2,3-diamino-2,3-dideoxy-glucose as lipid A backbone sugar. In contrast, three representatives of the genus Rhizobium, as well as the phylogenetically related species Agrobacterium tumefaciens, contain solely glucosamine as lipid A backbone sugar. These findings support independent studies on the phylogenetical relatedness based on 16S rRNA-data of the genus Bradyrhizobium with "Pseudomonas carboxydovorans" and Rhodopseudomonas palustris, which form a tight phylogenetical cluster and which all contain the 2,3-diamino-2,3-dideoxy-glucose-containing lipid A. The relatedness of these species to the glucosamine-containing species of the genus Rhizobium and to Agrobacterium tumefaciens is rather distant as documented by 16S rRNA studies.
Asunto(s)
Glucosamina/análogos & derivados , Lípido A/análisis , Lipopolisacáridos/análisis , Pseudomonas/análisis , Rhizobiaceae/análisis , Electroforesis en Gel de Poliacrilamida , Glucosamina/análisis , Filogenia , Pseudomonas/clasificación , Pseudomonas/crecimiento & desarrollo , Rhizobiaceae/clasificación , Rhizobiaceae/crecimiento & desarrollo , Rhizobium/análisis , Rhizobium/clasificación , Rhizobium/crecimiento & desarrolloRESUMEN
Mutants of Rhizobium meliloti have been isolated which are deficient in exopolysaccharide (EPS) production and effective nodulation of alfalfa (J. A. Leigh, E. R. Signer, and G. C. Walker, Proc. Natl. Acad. Sci. USA 82:6231-6235, 1985). We isolated approximately 100 analogous EPS-deficient (Exo) mutants of the closely related plant pathogen Agrobacterium tumefaciens, including strains whose EPS deficiencies were specifically complemented by each of five cloned R. meliloti exo loci. We also cloned A. tumefaciens genes which complemented EPS defects in three of the R. meliloti Exo mutants. In two of these cases, symbiotic defects were also complemented. All of the A. tumefaciens Exo mutants formed normal crown gall tumors on four different plant hosts, except ExoC mutants, which were nontumorigenic and unable to attach to plant cells in vitro. Like their R. meliloti counterparts, A. tumefaciens Exo mutants were deficient in production of succinoglycan, the major acidic EPS species produced by both genera. A. tumefaciens ExoC mutants also produced extremely low levels of another major EPS, cyclic 1,2-beta-D-glucan. This deficiency has been noted previously in a different set of nontumorigenic, attachment-defective A. tumefaciens mutants.
Asunto(s)
Polisacáridos Bacterianos/biosíntesis , Rhizobium/metabolismo , Prueba de Complementación Genética , Mutación , Tumores de Planta/microbiología , Rhizobium/genética , SimbiosisRESUMEN
The cell surface polysaccharides of wild-type Bradyrhizobium japonicum USDA 110 and a nonnodulating mutant, strain HS123, were analyzed. The capsular polysaccharide (CPS) and exopolysaccharide (EPS) of the wild type and the mutant strain do not differ in their sugar composition. CPS and EPS are composed of mannose, 4-O-methylgalactose/galactose, glucose, and galacturonic acid in a ratio of 1:1:2:1, respectively. H nuclear magnetic resonance spectra of the EPS and CPS of the wild type and mutant strain are very similar, but not identical, suggesting minor structural variation in these polysaccharides. The lipopolysaccharides (LPS) of the above two strains were purified, and their compositions were determined. Gross differences in the chemical compositions of the two LPS were observed. Chemical and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analyses indicated that strain HS123 is a rough-type mutant lacking a complete LPS. The LPS of mutant strain HS123 is composed of mannose, glucose, glucosamine, 2-keto-3-deoxyoctulosonic acid, and lipid A. The wild-type LPS is composed of fucose, xylose, arabinose, mannose, glucose, fucosamine, quinovosamine, glucosamine, uronic acid, 2-keto-3-deoxyoctulosonic acid, and lipid A. Preliminary sugar analysis of lipid A from B. japonicum identified mannose, while traces of glucosamine were detected. 3-Hydroxydodecanoic and 3-hydroxytetradecanoic acids formed a major portion of the fatty acids in lipid A. Lesser quantities of nonhydroxylated 16:0, 18:0, 22:0, and 24:0 acids also were detected.
Asunto(s)
Mutación , Polisacáridos/análisis , Rhizobium/análisis , Carbohidratos/análisis , Electroforesis en Gel de Poliacrilamida , Espectroscopía de Resonancia Magnética , Rhizobium/genéticaRESUMEN
Phenol-water cell extracts of virulent Agrobacterium tumefaciens A348 and several avirulent mutants with a reduced ability to attach to plant surfaces were examined. A low-molecular-weight 2-linked-beta-D-glucan was identified in the cell wall extracts of the virulent wild-type strain. Analyses of phenol-water extracts and culture filtrates of four mutant strains showed that the mutants did not produce any 2-linked-beta-D-glucan. When these mutants were complemented, the ability to produce the glucan described above was restored. These results suggest that there is a role for 2-linked-beta-D-glucans in the attachment of A. tumefaciens to plant cells. One avirulent, attachment-defective mutant retained its ability to produce the low-molecular-weight glucan. This mutation, however, mapped to a different transcriptional unit than the mutants deficient in the glucan described above. Thus, it appears that 2-linked-beta-D-glucan is only one component that may be necessary for attachment of A. tumefaciens to plant cell surfaces.
Asunto(s)
Glucanos/fisiología , Rhizobium/patogenicidad , Adhesividad , Glucanos/análisis , Espectroscopía de Resonancia Magnética , Mutación , Rhizobium/análisis , Rhizobium/genética , VirulenciaRESUMEN
A bacteriophage (phage TN1) that lyses Rhizobium japonicum 3I1b110 was isolated from Tennessee soil. Structurally, this phage resembles the Escherichia coli phage T4, having an icosahedral head (47 by 60 nm) and a contractile tail (17 by 80 nm). An interesting feature of this phage is that it lyses all of the symbiotic defective mutants derived from R. japonicum 3I1b110 that were tested, except one, mutant strain HS123. Mutant strain HS123 is a non-nodulating mutant that is defective in attachment to soybean roots. Since Rhizobium attachment to host roots is thought to be mediated by a specific cell surface interaction, it is likely that mutant strain HS123 is defective in some way in its cell surface. Mutant strain HS123 bound soybean lectin to the same extent as the wild type as measured by the binding of tritium-labeled lectin. Phage TN1 did not attach to the surface of strain HS123, nor did cells of strain HS123 inactivate phage TN1. A hot phenol-water cell extract from the wild-type inactivated phage TN1, whereas a similar cell extract from mutant HS123 did not. Capsular polysaccharide isolated from mutant or wild type did not inactivate the phage. Capsular polysaccharide and exopolysaccharide from the mutant and wild type do not differ in sugar composition. These results indicate that capsular polysaccharide may not play a role in attachment to the plant root surface and that other cell wall components may be important.