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1.
Am J Sports Med ; 50(7): 1788-1797, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35648628

RESUMEN

BACKGROUND: Patients with anterior cruciate ligament (ACL) revision report lower outcome scores on validated knee questionnaires postoperatively compared to cohorts with primary ACL reconstruction. In a previously active population, it is unclear if patient-reported outcomes (PROs) are associated with a return to activity (RTA) or vary by sports participation level (higher level vs. recreational athletes). HYPOTHESES: Individual RTA would be associated with improved outcomes (ie, decreased knee symptoms, pain, function) as measured using validated PROs. Recreational participants would report lower PROs compared with higher level athletes and be less likely to RTA. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: There were 862 patients who underwent a revision ACL reconstruction (rACLR) and self-reported physical activity at any level preoperatively. Those who did not RTA reported no activity 2 years after revision. Baseline data included patient characteristics, surgical history and characteristics, and PROs: International Knee Documentation Committee questionnaire, Marx Activity Rating Scale, Knee injury and Osteoarthritis Outcome Score, and the Western Ontario and McMaster Universities Osteoarthritis Index. A binary indicator was used to identify patients with same/better PROs versus worse outcomes compared with baseline, quantifying the magnitude of change in each direction, respectively. Multivariable regression models were used to evaluate risk factors for not returning to activity, the association of 2-year PROs after rACLR surgery by RTA status, and whether each PRO and RTA status differed by participation level. RESULTS: At 2 years postoperatively, approximately 15% did not RTA, with current smokers (adjusted odds ratio [aOR] = 3.3; P = .001), female patients (aOR = 2.9; P < .001), recreational participants (aOR = 2.0; P = .016), and those with a previous medial meniscal excision (aOR = 1.9; P = .013) having higher odds of not returning. In multivariate models, not returning to activity was significantly associated with having worse PROs at 2 years; however, no clinically meaningful differences in PROs at 2 years were seen between participation levels. CONCLUSION: Recreational-level participants were twice as likely to not RTA compared with those participating at higher levels. Within a previously active cohort, no RTA was a significant predictor of lower PROs after rACLR. However, among patients who did RTA after rACLR, approximately 20% reported lower outcome scores. Most patients with rACLR who were active at baseline improved over time; however, patients who reported worse outcomes at 2 years had a clinically meaningful decline across all PROs.


Asunto(s)
Lesiones del Ligamento Cruzado Anterior , Osteoartritis , Ligamento Cruzado Anterior/cirugía , Lesiones del Ligamento Cruzado Anterior/cirugía , Estudios de Cohortes , Femenino , Humanos , Osteoartritis/cirugía , Reoperación
2.
Am J Sports Med ; 49(10): 2589-2598, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34260326

RESUMEN

BACKGROUND: Although graft choice may be limited in the revision setting based on previously used grafts, most surgeons believe that graft choice for anterior cruciate ligament (ACL) reconstruction is an important factor related to outcome. HYPOTHESIS: In the ACL revision setting, there would be no difference between autograft and allograft in rerupture rate and patient-reported outcomes (PROs) at 6-year follow-up. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Patients who had revision surgery were identified and prospectively enrolled in this cohort study by 83 surgeons over 52 sites. Data collected included baseline characteristics, surgical technique and pathology, and a series of validated PRO measures. Patients were followed up at 6 years and asked to complete the identical set of PRO instruments. Incidence of additional surgery and reoperation because of graft failure were also recorded. Multivariable regression models were used to determine the predictors (risk factors) of PROs, graft rerupture, and reoperation at 6 years after revision surgery. RESULTS: A total of 1234 patients including 716 (58%) men were enrolled. A total of 325 (26%) underwent revision using a bone-patellar tendon-bone (BTB) autograft; 251 (20%), soft tissue autograft; 289 (23%), BTB allograft; 302 (25%), soft tissue allograft; and 67 (5%), other graft. Questionnaires and telephone follow-up for subsequent surgery information were obtained for 809 (66%) patients, while telephone follow-up was only obtained for an additional 128 patients for the total follow-up on 949 (77%) patients. Graft choice was a significant predictor of 6-year Marx Activity Rating Scale scores (P = .024). Specifically, patients who received a BTB autograft for revision reconstruction had higher activity levels than did patients who received a BTB allograft (odds ratio [OR], 1.92; 95% CI, 1.25-2.94). Graft rerupture was reported in 5.8% (55/949) of patients by their 6-year follow-up: 3.5% (16/455) of patients with autografts and 8.4% (37/441) of patients with allografts. Use of a BTB autograft for revision resulted in patients being 4.2 times less likely to sustain a subsequent graft rupture than if a BTB allograft were utilized (P = .011; 95% CI, 1.56-11.27). No significant differences were found in graft rerupture rates between BTB autograft and soft tissue autografts (P = .87) or between BTB autografts and soft tissue allografts (P = .36). Use of an autograft was found to be a significant predictor of having fewer reoperations within 6 years compared with using an allograft (P = .010; OR, 0.56; 95% CI, 0.36-0.87). CONCLUSION: BTB and soft tissue autografts had a decreased risk in graft rerupture compared with BTB allografts. BTB autografts were associated with higher activity level than were BTB allografts at 6 years after revision reconstruction. Surgeons and patients should consider this information when choosing a graft for revision ACL reconstruction.


Asunto(s)
Lesiones del Ligamento Cruzado Anterior , Reconstrucción del Ligamento Cruzado Anterior , Lesiones del Ligamento Cruzado Anterior/cirugía , Autoinjertos , Plastía con Hueso-Tendón Rotuliano-Hueso , Estudios de Cohortes , Humanos , Masculino , Reoperación , Trasplante Autólogo
3.
Am J Sports Med ; 48(12): 2978-2985, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32822238

RESUMEN

BACKGROUND: Meniscal preservation has been demonstrated to contribute to long-term knee health. This has been a successful intervention in patients with isolated tears and tears associated with anterior cruciate ligament (ACL) reconstruction. However, the results of meniscal repair in the setting of revision ACL reconstruction have not been documented. PURPOSE: To examine the prevalence and 2-year operative success rate of meniscal repairs in the revision ACL setting. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: All cases of revision ACL reconstruction with concomitant meniscal repair from a multicenter group between 2006 and 2011 were selected. Two-year follow-up was obtained by phone and email to determine whether any subsequent surgery had occurred to either knee since the initial revision ACL reconstruction. If so, operative reports were obtained, whenever possible, to verify the pathologic condition and subsequent treatment. RESULTS: In total, 218 patients (18%) from 1205 revision ACL reconstructions underwent concurrent meniscal repairs. There were 235 repairs performed: 153 medial, 48 lateral, and 17 medial and lateral. The majority of these repairs (n = 178; 76%) were performed with all-inside techniques. Two-year surgical follow-up was obtained on 90% (197/218) of the cohort. Overall, the meniscal repair failure rate was 8.6% (17/197) at 2 years. Of the 17 failures, 15 were medial (13 all-inside, 2 inside-out) and 2 were lateral (both all-inside). Four medial failures were treated in conjunction with a subsequent repeat revision ACL reconstruction. CONCLUSION: Meniscal repair in the revision ACL reconstruction setting does not have a high failure rate at 2-year follow-up. Failure rates for medial and lateral repairs were both <10% and consistent with success rates of primary ACL reconstruction meniscal repair. Medial tears underwent reoperation for failure at a significantly higher rate than lateral tears.


Asunto(s)
Lesiones del Ligamento Cruzado Anterior , Reconstrucción del Ligamento Cruzado Anterior , Reoperación/estadística & datos numéricos , Lesiones de Menisco Tibial , Lesiones del Ligamento Cruzado Anterior/cirugía , Estudios de Casos y Controles , Humanos , Meniscos Tibiales/cirugía , Lesiones de Menisco Tibial/cirugía
4.
Arch Pediatr ; 26(6): 374-376, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31506230

RESUMEN

Group B Streptococcus is the most frequent cause of neonatal sepsis. However, recurrences are rare. We report a case of recurrent meningitis due to Streptococcus B in a 2-month-old infant. Streptococcus B identified was hypervirulent clone ST-17 serotype III, which is known for its neurotropism. We found five other cases of recurrent group B streptococcal meningitis in the literature, which we report here. Many reports have identified breastfeeding and persistent colonization as the mode of transmission in recurrent Streptococcus B infections. We also discuss different ways to prevent recurrent group B streptococcal infections. Oral antibiotic therapy against carriage does not seem to be effective and there is no consensus on management of breastfeeding.


Asunto(s)
Meningitis Bacterianas/diagnóstico , Infecciones Estreptocócicas/diagnóstico , Streptococcus agalactiae/aislamiento & purificación , Antibacterianos/uso terapéutico , Femenino , Humanos , Lactante , Meningitis Bacterianas/tratamiento farmacológico , Recurrencia , Infecciones Estreptocócicas/tratamiento farmacológico
5.
Am J Sports Med ; 47(10): 2394-2401, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31318611

RESUMEN

BACKGROUND: Patient-reported outcomes (PROs) are a valid measure of results after revision anterior cruciate ligament (ACL) reconstruction. Revision ACL reconstruction has been documented to have worse outcomes when compared with primary ACL reconstruction. Understanding positive and negative predictors of PROs will allow surgeons to modify and potentially improve outcome for patients. PURPOSE/HYPOTHESIS: The purpose was to describe PROs after revision ACL reconstruction and test the hypothesis that patient- and technique-specific variables are associated with these outcomes. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Patients undergoing revision ACL reconstruction were identified and prospectively enrolled by 83 surgeons over 52 sites. Data included baseline demographics, surgical technique and pathology, and a series of validated PRO instruments: International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index, and Marx Activity Rating Scale. Patients were followed up at 2 years and asked to complete the identical set of outcome instruments. Multivariate regression models were used to control for a variety of demographic and surgical factors to determine the positive and negative predictors of PRO scores at 2 years after revision surgery. RESULTS: A total of 1205 patients met the inclusion criteria and were successfully enrolled: 697 (58%) were male, with a median cohort age of 26 years. The median time since their most recent previous ACL reconstruction was 3.4 years. Two-year questionnaire follow-up was obtained from 989 patients (82%). The most significant positive predictors of 2-year IKDC scores were a high baseline IKDC score, high baseline Marx activity level, male sex, and having a longer time since the most recent previous ACL reconstruction, while negative predictors included having a lateral meniscectomy before the revision ACL reconstruction or having grade 3/4 chondrosis in either the trochlear groove or the medial tibial plateau at the time of the revision surgery. For KOOS, having a high baseline score and having a longer time between the most recent previous ACL reconstruction and revision surgery were significant positive predictors for having a better (ie, higher) 2-year KOOS, while having a lateral meniscectomy before the revision ACL reconstruction was a consistent predictor for having a significantly worse (ie, lower) 2-year KOOS. Statistically significant positive predictors for 2-year Marx activity levels included higher baseline Marx activity levels, younger age, male sex, and being a nonsmoker. Negative 2-year activity level predictors included having an allograft or a biologic enhancement at the time of revision surgery. CONCLUSION: PROs after revision ACL reconstruction are associated with a variety of patient- and surgeon-related variables. Understanding positive and negative predictors of PROs will allow surgeons to guide patient expectations as well as potentially improve outcomes.


Asunto(s)
Lesiones del Ligamento Cruzado Anterior/cirugía , Reconstrucción del Ligamento Cruzado Anterior/métodos , Medición de Resultados Informados por el Paciente , Adolescente , Adulto , Enfermedades de los Cartílagos/cirugía , Estudios de Cohortes , Femenino , Humanos , Articulación de la Rodilla/cirugía , Masculino , Meniscectomía/estadística & datos numéricos , Persona de Mediana Edad , Reoperación , Encuestas y Cuestionarios , Adulto Joven
6.
Am J Sports Med ; 46(12): 2836-2841, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29882693

RESUMEN

BACKGROUND: The occurrence of physiologic knee hyperextension (HE) in the revision anterior cruciate ligament reconstruction (ACLR) population and its effect on outcomes have yet to be reported. Hypothesis/Purpose: The prevalence of knee HE in revision ACLR and its effect on 2-year outcome were studied with the hypothesis that preoperative physiologic knee HE ≥5° is a risk factor for anterior cruciate ligament (ACL) graft rupture. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Patients undergoing revision ACLR were identified and prospectively enrolled between 2006 and 2011. Study inclusion criteria were patients undergoing single-bundle graft reconstructions. Patients were followed up at 2 years and asked to complete an identical set of outcome instruments (International Knee Documentation Committee, Knee injury and Osteoarthritis Outcome Score, WOMAC, and Marx Activity Rating Scale) as well as provide information regarding revision ACL graft failure. A regression model with graft failure as the dependent variable included age, sex, graft type at the time of the revision ACL surgery, and physiologic preoperative passive HE ≥5° (yes/no) to assess these as potential risk factors for clinical outcomes 2 years after revision ACLR. RESULTS: Analyses included 1145 patients, for whom 2-year follow-up was attained for 91%. The median age was 26 years, with age being a continuous variable. Those below the median were grouped as "younger" and those above as "older" (age: interquartile range = 20, 35 years), and 42% of patients were female. There were 50% autografts, 48% allografts, and 2% that had a combination of autograft plus allograft. Passive knee HE ≥5° was present in 374 (33%) patients in the revision cohort, with 52% being female. Graft rupture at 2-year follow-up occurred in 34 cases in the entire cohort, of which 12 were in the HE ≥5° group (3.2% failure rate) and 22 in the non-HE group (2.9% failure rate). The median age of patients who failed was 19 years, as opposed to 26 years for those with intact grafts. Three variables in the regression model were significant predictors of graft failure: younger age (odds ratio [OR] = 3.6; 95% CI, 1.6-7.9; P = .002), use of allograft (OR = 3.3; 95% CI, 1.5-7.4; P = .003), and HE ≥5° (OR = 2.12; 95% CI, 1.1-4.7; P = .03). CONCLUSION: This study revealed that preoperative physiologic passive knee HE ≥5° is present in one-third of patients who undergo revision ACLR. HE ≥5° was an independent significant predictor of graft failure after revision ACLR with a >2-fold OR of subsequent graft rupture in revision ACL surgery. Registration: NCT00625885 ( ClinicalTrials.gov identifier).


Asunto(s)
Lesiones del Ligamento Cruzado Anterior/cirugía , Reconstrucción del Ligamento Cruzado Anterior/métodos , Adolescente , Adulto , Ligamento Cruzado Anterior/cirugía , Lesiones del Ligamento Cruzado Anterior/fisiopatología , Femenino , Humanos , Articulación de la Rodilla/fisiopatología , Articulación de la Rodilla/cirugía , Masculino , Cuidados Preoperatorios , Pronóstico , Estudios Prospectivos , Rango del Movimiento Articular , Reoperación , Factores de Riesgo , Rotura , Trasplante Autólogo , Adulto Joven
7.
J Antimicrob Chemother ; 61(3): 504-8, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18222958

RESUMEN

OBJECTIVES: Escherichia coli producing CTX-M-15 enzyme began to rapidly spread in the UK from around 2003 but other types also occur, notably CTX-M-14. We examined breasts from UK-reared (n = 62) and imported (n = 27) chickens as potential sources of quinolone-resistant E. coli with bla(CTX-M) genes. A further 40 samples for which the country of rearing could not be identified were examined. METHODS: During 2006, 129 fresh and frozen chicken breast fillets were purchased from retail outlets in the West Midlands. These were cultured for E. coli on CLED agar containing 8 mg/L ciprofloxacin and carrying a 10 microg cefpodoxime disc. Resistant isolates were identified and typed by RAPD fingerprinting; bla(CTX-M) was identified by PCR and genotyped by reverse-line hybridization. RESULTS: The country of rearing was identified from the packaging for 89 of 129 purchased samples. Only one of the 62 UK-reared chicken samples carried E. coli producing a CTX-M-1 enzyme, whereas 10 of 27 samples reared overseas had E. coli with CTX-M enzymes. Specifically, 4/10 Brazilian, 3/4 Brazilian/Polish/French, and 2/2 Dutch samples had E. coli with CTX-M-2 enzymes. Six of 40 samples for which the country of rearing was not known had producers of CTX-M enzymes, 5 of them with CTX-M-14. CONCLUSIONS: Quinolone-resistant E. coli with various CTX-M beta-lactamase genes that are common in human infections worldwide were found in imported chicken breasts, indicating a possible source for gut colonization. Samples from Brazil were commonly positive for E. coli with CTX-M-2, the dominant bla(CTX-M) genotype from human infections in South America, which is currently rare in clinical infections in the UK. CTX-M-15, the dominant CTX-M type in human infections in the UK, was not found in chicken isolates, suggesting that the UK-reared chickens are not a reservoir of CTX-M-15.


Asunto(s)
Farmacorresistencia Bacteriana/fisiología , Escherichia coli/enzimología , Escherichia coli/aislamiento & purificación , Microbiología de Alimentos , Carne/microbiología , beta-Lactamasas/aislamiento & purificación , Animales , Brasil , Pollos , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/prevención & control , Europa (Continente) , Contaminación de Alimentos/análisis , Contaminación de Alimentos/prevención & control , Reino Unido , beta-Lactamasas/biosíntesis
8.
Onderstepoort J Vet Res ; 74(4): 307-14, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18453240

RESUMEN

Krimpsiekte, a chronic form of cardiac glycoside poisoning, is an important plant-induced intoxication of small stock in South Africa. It is caused by cumulative, neurotoxic bufadienolides, such as cotyledoside. A cotyledoside-bovine serum albumin conjugate was synthesized to immunize animals. The efficacy of the cotyledoside-conjugate in inducing an immunological response was ascertained in rabbits (n = 4) and sheep (n = 4) by determining cotyledoside antibody titres with an ELISA using cotyledoside-hen ovalbumin as antigen. The formation of anticotyledoside antibodies was induced in both rabbits and sheep following immunization with the cotyledoside-protein conjugate. Protection provided by the vaccine was demonstrated by challenging sheep (n = 4) with repeated, daily doses of cotyledoside (0.015 mg/kg) administered intravenously, commencing 45 days after the initial vaccination. One control animal died on Day 3 of the challenge period and the other was severely affected after administration of the third cotyledoside dose. The immunized ewes (n = 2) remained clinically unaffected and the challenge was suspended following six daily injections. Vaccination as a means of preventing krimpsiekte seems to be quite feasible and deserves further investigation.


Asunto(s)
Bufanólidos/inmunología , Glicósidos Cardíacos/envenenamiento , Intoxicación por Plantas/veterinaria , Enfermedades de las Ovejas/prevención & control , Vacunación/veterinaria , Animales , Anticuerpos/sangre , Formación de Anticuerpos , Bufanólidos/administración & dosificación , Relación Dosis-Respuesta a Droga , Relación Dosis-Respuesta Inmunológica , Ensayo de Inmunoadsorción Enzimática/métodos , Ensayo de Inmunoadsorción Enzimática/veterinaria , Femenino , Masculino , Miocardio/patología , Intoxicación por Plantas/prevención & control , Plantas Tóxicas , Conejos , Distribución Aleatoria , Ovinos , Vacunación/métodos
9.
Am J Orthop (Belle Mead NJ) ; 29(7): 557-62, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10926407

RESUMEN

Investigators have shown that significant segmental motion occurs in patients immobilized in halo vests. One cadaver study showed that this is decreased with a posterior pad added to the construct. To improve nonoperative care of patients with cervical trauma, segmental cervical motion was evaluated in normal volunteers immobilized in a halo vest with and without a posterior pad. Two commonly used methods to measure sagittal angulation were used. Thirty normal volunteers were placed in halo vests by using positioning pins on the cranium. A sphygmomanometer attached to the posterior uprights of the vest inflated to 40 mm Hg was used as a posterior pad at the greatest visible lordosis. Lateral radiographs of the cervical spine were taken with volunteers in the upright and supine positions with and without the posterior pad inflated. Radiographs were randomly sorted and were each read twice by 3 readers. Measurements of the posterior atlantodental interval, sagittal displacement, and sagittal rotation were recorded using 2 different methods: the Buetti-Bauml method, which uses lines drawn along the posterior vertebral bodies, and the method of White and colleagues, which uses lines drawn along the inferior vertebral bodies. Inflation status of the pad showed no statistically significant difference in any of the measured variables. This was true for both methods of measurement. Application of a posterior pad to the halo vest did not show any change in the segmental motion of the cervical spine in normal volunteers.


Asunto(s)
Vértebras Cervicales/lesiones , Movimientos de la Cabeza/fisiología , Aparatos Ortopédicos , Traumatismos Vertebrales/rehabilitación , Adulto , Vértebras Cervicales/fisiopatología , Diseño de Equipo , Femenino , Humanos , Inmovilización , Masculino , Presión , Traumatismos Vertebrales/fisiopatología
10.
Immunology ; 96(4): 507-10, 1999 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10233734

RESUMEN

A eukaryotic plasmid DNA carrying the AACGTT CpG motif in its ampR gene is a 'danger' signal for mice and caused an increase in the specific antibody titres of fish and mice after immunization with beta-galactosidase (beta-gal). A second pUC-based plasmid, which is inactive in mice and contains the GACGTC CpG motif in its cytomegalovirus (CMV) promoter, had no effect on antibody responses to beta-gal in either fish or mice. A synthetic oligonucleotide, which contains the GACGTT motif, potentiated antibody responses to co-administered beta-gal protein in mice, but not in fish. This is early evidence that lower and higher vertebrates recognize different unmethylated CpG motifs as 'danger' signals. In addition, plasmid DNA expressing mouse granulocyte-macrophage colony-stimulating factor (GM-CSF) had a marked effect on cytotoxic T-cell-like activity in fish by reducing the average number of myofibres that expressed beta-gal, 28 days after co-injection with plasmid DNA expressing beta-gal. Although the mechanism by which the mouse GM-CSF exerted its biological effects in fish is unknown, this finding might have important implications for fish vaccination, particularly when cytotoxic T cells may play a critical role.


Asunto(s)
Islas de CpG/inmunología , Peces/inmunología , Factor Estimulante de Colonias de Granulocitos y Macrófagos/inmunología , Vacunas de ADN/inmunología , Animales , Femenino , Inmunidad Celular , Inmunoglobulina G/biosíntesis , Ratones , Ratones Endogámicos BALB C , Especificidad de la Especie , Linfocitos T/inmunología , beta-Galactosidasa/inmunología
11.
J Nat Prod ; 61(12): 1476-81, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9868147

RESUMEN

We have previously described the structures of four novel unconjugated bufadienolides in the ovary of the toad, Bufo marinus. In this study, we report the separation and characterization of three novel bufadienolide conjugates. These compounds were purified by HPLC, and their structures were determined to be 11alpha, 19-dihydroxytelocinobufagin-3-(12-hydroxydodecanoic acid) ester, 11alpha,19-dihydroxytelocinobufagin-3-(14-hydroxy-7-tetra decenoic acid) ester, and 11alpha, 19-dihydroxytelocinobufagin-3-(14-hydroxytetradecanoic acid) ester on the basis of NMR and MS data. Numerous dicarboxylic acid esters of bufadienolides have previously been described, but the three bufadienolide conjugates described in this report differ from previously described esters in that they contain hydroxylated monocarboxylic acids. The function of these three conjugates is not known but they are, like bufotoxins, potent inhibitors of Na+, K+-ATPase and may play a developmental role in the differentiation of toad oocytes.


Asunto(s)
Digoxina , Inhibidores Enzimáticos/aislamiento & purificación , Ovario/química , Saponinas/aislamiento & purificación , ATPasa Intercambiadora de Sodio-Potasio/antagonistas & inhibidores , Animales , Bufo marinus , Cardenólidos , Cromatografía de Gases , Cromatografía Líquida de Alta Presión , Perros , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Femenino , Saponinas/química , Saponinas/farmacología
12.
Comp Biochem Physiol A Physiol ; 118(3): 599-606, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9406436

RESUMEN

Toads of the genus Bufo are highly resistant to the toxic effects of digitalis glycosides, and the Na+,K(+)-ATPase of all toad tissues studied to date has been relatively insensitive to inhibition by digitalis and related compounds. In studies of brain microsomal preparations from two toad species, Bufo marinus and Bufo viridis, inhibition of ATPase activity and displacement of [3H]ouabain from Na+,K(+)-ATPase occurred over broad ranges of ouabain or bufalin concentrations, consistent with the possibility that more than one Na+,K(+)-ATPase isoform may be present in toad brain. The data could be fitted to one- or two-site models, both of which were consistent with the presence of Na+,K(+)-ATPase activity with high sensitivity to ouabain and bufalin. Ki (concentration capable of producing 50% inhibition of activity) values for ouabain in the one-site model were in the 0.2 to 3.7 microM range, whereas Ki1 values in the two-site model ranged from 0.085 to 0.85 microM, indicating that brain ATPase was at least three orders of magnitude more sensitive to ouabain than B. marinus bladder ATPase (Ki = 5940 microM). Ouabain was also an effective inhibitor of 86Rb+ uptake in B. marinus brain tissue slices (Ki = 3.1 microM in the one-site model; Ki1 = 0.03 microM in the two-site model). However, the relative contribution of the high ouabain-sensitivity site to the total activity was 17% in the transport assay as compared with 63% in the Na+,K(+)-ATPase enzymatic assay. We conclude that a highly ouabain-sensitive Na+,K(+)-ATPase activity is present and functional in toad brain but that its function may be partially inhibited in vivo.


Asunto(s)
Bufonidae/metabolismo , Inhibidores Enzimáticos/farmacología , Ouabaína/farmacología , ATPasa Intercambiadora de Sodio-Potasio/antagonistas & inhibidores , Animales , Sitios de Unión , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Bufo marinus/metabolismo , Glicósidos Digitálicos/metabolismo , Glicósidos Digitálicos/toxicidad , Femenino , Técnicas In Vitro , Transporte Iónico , Masculino , Microsomas/efectos de los fármacos , Microsomas/metabolismo , Modelos Biológicos , Ouabaína/metabolismo , Rubidio/farmacocinética , Temperatura , Vejiga Urinaria/efectos de los fármacos , Vejiga Urinaria/metabolismo
13.
Chem Pharm Bull (Tokyo) ; 45(2): 249-54, 1997 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9118440

RESUMEN

We have identified a novel cardiac steroid, 11,19-epoxy-19-methoxytelocinobufagin, named marinosin (1), in the skin of the toad, Bufo marinus (L.) Schneider. The treatment of compound 1 with 50% CH3CN containing 0.1% trifluoroacetic acid yielded a 11 alpha-hydroxyhellebrigenin (2), which has not previously been isolated from animals or plants. The structures of both compounds were established from spectral data obtained by NMR and MS, which were compared with those of a reference bufadienolide, 11 alpha-hydroxytelocinobufagin. Compounds 1 and 2 have A/B cis and C/D cis configuration, which is characteristic of bufadienolides such as bufalin and marinobufagin. However, the stereo-structure of compound 1 was characterized by a boat form of the B ring, which is different from the chair form in typical bufadienolides such as compound 2. Compounds 1 and 2 both exhibited activity, as demonstrated by inhibition of Na+, K(+)-ATPase enzymatic activity and by inhibition of the binding of [3H]ouabain to Na+, K(+)-ATPase; however, marinosin (1) was as less effective inhibitor than 2, 11 alpha-hydroxyhellebrigenin. We have identified compound 2 in toad venom, but not in the skin.


Asunto(s)
Bufanólidos/química , Piel/química , Animales , Bufanólidos/farmacología , Bufo marinus , Cromatografía Líquida de Alta Presión , Femenino , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Ouabaína/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/antagonistas & inhibidores
14.
Leadersh Health Serv ; 5(5): 13-6, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-10161453

RESUMEN

When a B.C. health commission proposed strategies for promoting cultural awareness in healthcare, members of one hospital staff took up the challenge. With no budget and in addition to their regular duties, they researched and developed practical tools for healthcare workers in the midst of Victoria's diverse community.


Asunto(s)
Diversidad Cultural , Personal de Salud , Actitud del Personal de Salud , Colombia Británica , Humanos , Relaciones Interprofesionales , Relaciones Profesional-Paciente
15.
Am J Physiol ; 271(2 Pt 2): R325-32, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8770130

RESUMEN

Three major groups of endogenous digitalis-like substances (EDLS) have been identified in the plasma of the toad, Bufo marinus. One group of compounds, present in fresh plasma, is composed of chromatographically homogeneous polar conjugates, principally bufadienolide 3-sulfates, which exhibit relatively weak Na(+)-K(+)-adenosinetriphosphatase (ATPase) inhibitory activity. A second and larger group of compounds, also found in fresh plasma, includes chromatographically heterogeneous conjugates, which are effective inhibitors of Na(+)-K(+)-ATPase; these compounds possess properties similar to those of bufotoxins. The third group of EDLS consists of free unconjugated bufadienolides, which are also effective Na(+)-K(+)-ATPase inhibitors. These unconjugated bufadienolides are present in relatively low concentrations in fresh toad plasma, but appreciable quantities are enzymatically generated from conjugates (believed to consist principally of bufotoxins) during the in vitro incubation of plasma. We suggest that the extent to which circulating polar EDLS are enzymatically deconjugated in vivo may be important in the regulation of the digitalis-sensitive Na(+)-K(+)-ATPase of toad brain, the only known digitalis-sensitive Na(+)-K(+)-ATPase in the toad.


Asunto(s)
Bufo marinus/sangre , Digoxina , Inhibidores Enzimáticos/sangre , Saponinas/sangre , Animales , Bufanólidos/sangre , Bufanólidos/química , Cardenólidos , Cromatografía Líquida de Alta Presión , Estabilidad de Medicamentos , Femenino , Saponinas/química , ATPasa Intercambiadora de Sodio-Potasio/antagonistas & inhibidores
17.
Chem Pharm Bull (Tokyo) ; 44(1): 255-7, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8582043

RESUMEN

We found a novel substance, 3 beta-hydroxy-11,12-seco-5 beta, 14 beta-bufa-20,22-dienolide-11,14-olide-12-oic acid (1), which we called marinoic acid, in the skin of the toad, Bufo marinus. The structure was established from NMR and MS data. Like bufadienolides, marinoic acid contained an A/B ring structure in the cis configuration and a D/alpha-pyrone ring structure, but the structure of the C ring differed considerably from that of bufadienolides. Marinoic acid exhibited biological activity, as demonstrated by inhibition of Na+, K(+)-ATPase enzymatic activity, and by inhibition of [3H]ouabain binding to the digitalis receptor site on Na+, K(+)-ATPase, although marinoic acid was a less effective inhibitor than typical bufadienolides. Although marinoic acid cannot be classified as a bufadienolide, its chemical structure and its Na+, K(+)-ATPase inhibitory activity suggest that it is bufadienolide-related.


Asunto(s)
Bufanólidos/aislamiento & purificación , Cardiotónicos/aislamiento & purificación , Inhibidores Enzimáticos/aislamiento & purificación , Piel/química , Animales , Bufanólidos/química , Bufo marinus , Cardiotónicos/química , Inhibidores Enzimáticos/química , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , ATPasa Intercambiadora de Sodio-Potasio/antagonistas & inhibidores
18.
Ann Intern Med ; 123(9): 676-80, 1995 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-7574223

RESUMEN

OBJECTIVE: To assess the role of digitalis in the development of visual symptoms severe enough to warrant ophthalmologic consultation in patients who received digitalis and who had no other clinical or laboratory evidence of digitalis toxicity. DESIGN: Clinical case study. SETTING: Neuro-ophthalmology referral practice. PATIENTS: Six elderly patients (aged 66 to 85 years) who received digitalis were referred to ophthalmologists for evaluation of photopsia (five patients) or decreased visual acuity (one patient). No patient had chromatopsia or nonvisual clinical manifestations of digitalis intoxication at the time of examination. MEASUREMENTS: All patients had serum digitalis concentrations within or below the therapeutic range. In most patients, the electroretinographic cone b-wave implicit time was longer than normal. RESULTS: Discontinuation of digitalis therapy, which was possible in five patients, was followed by resolution of visual symptoms and by shortening of the b-wave implicit time. Characteristic features of digitalis-induced photopsia were its dependence on illumination and its tendency to be localized in peripheral visual fields. CONCLUSIONS: In an elderly patient receiving digitalis, the development of photopsia characterized by innumerable points of light in the peripheral visual fields or a decrease in visual acuity raises the possibility that the patient's visual disturbance may have been digitalis induced. Digitalis-induced visual disturbances other than chromatopsia or disturbances of color vision may occur in elderly patients who have no other clinical manifestations of digitalis intoxication and who have a serum digitalis concentration within or below the therapeutic range.


Asunto(s)
Glicósidos Digitálicos/efectos adversos , Trastornos de la Visión/inducido químicamente , Anciano , Anciano de 80 o más Años , Glicósidos Digitálicos/sangre , Electrorretinografía , Femenino , Humanos , Masculino , Trastornos de la Visión/diagnóstico
19.
J Lipid Res ; 35(9): 1646-51, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7806978

RESUMEN

The bile salts present in gallbladder bile of the toad, Bufo marinus, were found to consist of a mixture of bile alcohol sulfates and unconjugated bile acids. The major bile alcohol was 5 beta-bufol; 5 alpha- and 5 beta-cholestane-3 alpha,7 alpha,12 alpha, 26-tetrols occurred as the minor bile alcohols. Bile acids of Bufo marinus were cholic acid, allocholic acid, 3 alpha,7 alpha,12 alpha-trihydroxy-5 alpha- and 5 beta-cholestan-26-oic acids, 3 alpha,7 alpha,12 alpha-trihydroxy-5 alpha- and 5 beta-cholest-23-en-26-oic acids, 3 alpha,7 alpha,12 alpha, 26-tetrahydroxy-5 beta-cholestan-27-oic acid, and a C27 bile acid which has not been previously described. By chromatographic behavior, mass spectral data, and identification of the products of catalytic hydrogenation and ozonolysis, the structure of the new higher bile acid was elucidated as 3 alpha,7 alpha,12 alpha,26-tetrahydroxy-5 beta-cholest-23-en-27-oic acid. The bile salt pattern of Bufo marinus closely resembles that of Bufo vulgaris formosus, except for the absence of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholest-22-ene-24-carboxylic acid, the major bile acid of the latter toad.


Asunto(s)
Ácidos y Sales Biliares/química , Bufo marinus/metabolismo , Colestanoles/aislamiento & purificación , Animales , Ácidos y Sales Biliares/biosíntesis , Ácidos y Sales Biliares/aislamiento & purificación , Bufonidae/metabolismo , Colestanoles/química , Colestanoles/metabolismo , Cromatografía de Gases , Cromatografía de Gases y Espectrometría de Masas , Estructura Molecular , Especificidad de la Especie
20.
Ann Surg Oncol ; 1(4): 339-44, 1994 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7850533

RESUMEN

BACKGROUND: Although the etiology of gross cystic disease of the breast is unknown, elevated cyst concentrations of potassium (K+) (> 60 mM/L) may be related to symptoms. The purpose of this study was to clarify the mechanism(s) of K+ accumulation in breast cysts. METHODS: We assayed cyst fluids for factors known to exert effects on K+ transport, namely, endogenous digitalis-like inhibitors of Na+,K(+)-ATPase (NKA) and the neuropeptides gastrin-releasing peptide (GRP), calcitonin (CT), and calcitonin gene-related peptide (CGRP). RESULTS: Cyst fluid K+ was directly correlated with cyst volume, cyst NKA inhibitory activity (in ouabain equivalents), and cyst concentrations of calcitonin, GRP, and CGRP. Cyst fluid Na+ was inversely correlated with cyst fluid K+, cyst NKA inhibitory activity, cyst volume, and cyst fluid concentrations of calcitonin, GRP, and CGRP. NKA inhibitory activity correlated directly with GRP and CGRP. Immunocytochemistry localized GRP to breast cyst lining cells and areas of ductal and lobular epithelial hyperplasia in biopsies of 15 of 15 cysts and in 5 of 5 breast carcinomas, but not in (0 of 5) normal breast biopsies. Specificity of GRP staining was demonstrated by total abolition of reactivity after adsorption with synthetic GRP, but not after adsorption with synthetic substance P, neurokinin A, or neurokinin B. CONCLUSIONS: We conclude that both the concentrations of endogenous digitalis-like factors and the neuropeptides calcitonin, GRP, and CGRP in human breast cyst fluids are related to the concentrations of K+ and Na+ in breast cysts and to cyst volume.


Asunto(s)
Líquidos Corporales/metabolismo , Enfermedad Fibroquística de la Mama/metabolismo , Neuropéptidos/análisis , Potasio/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/análisis , Adulto , Transporte Biológico Activo , Líquidos Corporales/química , Calcitonina/análisis , Péptido Relacionado con Gen de Calcitonina/análisis , Femenino , Enfermedad Fibroquística de la Mama/química , Enfermedad Fibroquística de la Mama/patología , Péptido Liberador de Gastrina , Hormonas Gastrointestinales/análisis , Humanos , Inmunohistoquímica , Persona de Mediana Edad , Péptidos/análisis , Sodio/análisis
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