RESUMEN
Prenatal alcohol exposure can produce permanent alterations in brain structure and profound behavioral deficits. Mouse models can help discover mechanisms and identify potentially useful interventions. This study examined long-term influences of either a single or repeated alcohol exposure during the third-trimester equivalent on survival of new neurons in the hippocampus, behavioral performance on the Passive avoidance and Rotarod tasks, and the potential role of exercise as a therapeutic intervention. C57BL/6J male mice received either saline or 5g/kg ethanol split into two s.c. injections, two hours apart, on postnatal day (PD)7 (Experiment 1) or on PD5, 7 and 9 (Experiment 2). All mice were weaned on PD21 and received either a running wheel or remained sedentary from PD35-PD80/81. From PD36-45, mice received i.p. injections of 50mg/kg bromodeoxyuridine (BrdU) to label dividing cells. Behavioral testing occurred between PD72-79. Number of surviving BrdU+ cells and immature neurons (doublecortin; DCX+) was measured at PD80-81. Alcohol did not affect number of BrdU+ or DCX+ cells in either experiment. Running significantly increased number of BrdU+ and DCX+ cells in both treatment groups. Alcohol-induced deficits on Rotarod performance and acquisition of the Passive avoidance task (Day 1) were evident only in Experiment 2 and running rescued these deficits. These data suggest neonatal alcohol exposure does not result in long-term impairments in adult hippocampal neurogenesis in the mouse model. Three doses of ethanol were necessary to induce behavioral deficits. Finally, the mechanisms by which exercise ameliorated the neonatal alcohol induced behavioral deficits remain unknown.
Asunto(s)
Etanol/farmacología , Hipocampo/efectos de los fármacos , Actividad Motora/efectos de los fármacos , Neurogénesis/efectos de los fármacos , Animales , Conducta Animal , Supervivencia Celular/efectos de los fármacos , Proteína Doblecortina , Hipocampo/fisiología , Masculino , Ratones Endogámicos C57BL , Neurogénesis/fisiología , Neuronas/efectos de los fármacos , Condicionamiento Físico Animal/fisiologíaRESUMEN
Many marine fishes change sex in response to social cues when the dominance hierarchy is perturbed. Arginine-vasotocin (AVT) and the mammalian homolog arginine vasopressin are neuropeptides involved in social and reproductive behaviors across vertebrate taxa. The goal of this study was to determine whether AVT signaling influences aggression and expression of c-Fos, a marker of neuroplasticity, in key brain regions of the social decision circuit in Amphiprion ocellaris clownfish, a species where behavioral dominance precedes gonadal sex change from male to female. In experiment 1, juvenile clownfish (average mass 2.5g) were paired together in a tank (a total of 24 pairs), matched approximately for size with one fish randomly receiving either an intraperitoneal injection of the arginine vasopressin V1a receptor antagonist (Manning compound) or saline vehicle, and evaluated for aggressive and submissive behaviors over a 10-min period. The second experiment was a repeat of the first using five pairs of mature, reproductive males, except the animals interacted for 90-min immediately followed by euthanasia for immunohistochemical detection of c-Fos protein. Numbers of c-Fos-positive cells were quantified in the preoptic area of the hypothalamus (POA), the anterior tuberal nucleus (aTn), and periventricular nucleus of the posterior tuberculum (TPp). Manning compound significantly reduced aggression and the probability of winning the contest relative to saline (vehicle) controls. In experiment 2, saline-treated fish displayed approximately twice as many c-Fos-positive cells in the POA and 25% more in the TPp than the Manning-treated fish, no differences were observed in the aTn. Taken together, results suggest AVT signaling is necessary for aggressive behavior and expression of neuroplasticity in the POA and TPp that likely contributes to behavioral dominance and hence, sex change in A. ocellaris.
Asunto(s)
Hipotálamo Posterior/metabolismo , Área Preóptica/metabolismo , Proteínas Proto-Oncogénicas c-fos/metabolismo , Transducción de Señal/fisiología , Vasotocina/metabolismo , Factores de Edad , Agresión/fisiología , Animales , Arginina Vasopresina/análogos & derivados , Arginina Vasopresina/farmacología , Femenino , Peces , Jerarquia Social , Masculino , Transducción de Señal/efectos de los fármacos , Factores de Tiempo , Vasotocina/antagonistas & inhibidoresRESUMEN
Simultaneous current ramping and application of lower hybrid heating and current drive (LHCD) have produced a region with zero current density within measurement errors in the core ( r/a< or =0.2) of JET tokamak optimized shear discharges. The reduction of core current density is consistent with a simple physical explanation and numerical simulations of radial current diffusion including the effects of LHCD. However, the core current density is clamped at zero, indicating the existence of a physical mechanism which prevents it from becoming negative.
RESUMEN
Previous studies showed that following acute carbon tetrachloride (CCl(4)) treatment, interleukin-6 null (IL-6-/-) mice develop increased hepatocellular injury, defective regeneration, delayed wound healing, and increased hepatocyte apoptosis. Pretreatment with IL-6 prior to CCl(4) reduces injury, hepatocyte apoptosis, and accelerates regeneration in both IL-6-/- and +/+ livers. To demonstrate whether IL-6 can prevent liver injury that involves direct stimulation of hepatocyte apoptosis, IL-6-/- and +/+ mice were treated with the Fas agonist, Jo-2 mAb. At low Fas agonist doses, IL-6+/+ mice developed mild hepatic injury and survived, whereas IL-6-/- mice developed severe apoptotic hepatitis within 12 h and died. Pretreatment with IL-6 improved survival in IL-6-/- mice and reduced injury in both IL-6-/- and +/+ livers. The direct anti-apoptotic effects of IL-6 were demonstrated in vitro as IL-6 decreased Fas-mediated apoptosis in both IL-6-/- and +/+ primary hepatocyte cultures, and suggested that IL-6-/- hepatocytes have a pre-existing defect in anti-apoptotic pathways. After Fas activation, IL-6-/- livers demonstrated evidence of both proximal and distal alterations in the apoptotic pathways including elevated caspase 8 and 3 activation-associated fragments, and loss of cytochrome c staining. IL-6-/- livers had reduced pre-existing protein expression of the anti-apoptotic factors Bcl-2 and Bcl-xL as well as more rapid degradation of FLIP following Fas treatment that appeared to be post-transcriptionally regulated. FLIP is a crucial proximal inhibitor of caspase 8 activation in Fas, tumor necrosis factor, and DR3/DR4-mediated apoptosis, and Bcl-2 and Bcl-xL more downstream anti-apoptotic regulators. IL-6 may function as a critical anti-apoptotic factor in the liver by its ability to establish and maintain an adequate level of FLIP and downstream anti-apoptotic factors.
Asunto(s)
Proteínas Portadoras/metabolismo , Interleucina-6/farmacología , Péptidos y Proteínas de Señalización Intracelular , Hígado/patología , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Animales , Proteína Reguladora de Apoptosis Similar a CASP8 y FADD , Muerte Celular/efectos de los fármacos , Interleucina-6/metabolismo , Hígado/metabolismo , Ratones , Proteína bcl-X , Receptor fas/metabolismoRESUMEN
Nuclear factor kappaB (NF-kappaB) is rapidly activated during liver regeneration following partial hepatectomy or carbon tetrachloride (CCl(4))-mediated liver injury and is felt to be important in the antiapoptotic and regenerative responses. After partial hepatectomy, livers of mice deficient in the p50 subunit of NF-kappaB (p50(-/-)) showed a loss of NF-kappaB and decreased STAT3 transcription factor DNA binding activities. However, nuclear levels of the NF-kappaB p65 subunit were increased and peaked earlier in p50(-/-) livers. Both messenger RNA and cytoplasmic protein levels of the NF-kappaB inhibitor IkappaBalpha were lower in p50(-/-) livers, potentially accounting for the increase in p65 protein. Small effects on gene expression posthepatectomy were observed in p50(-/-) livers, but no effects were seen on hepatocyte DNA synthetic or mitotic responses, serum enzyme levels, or overall liver mass restoration. After CCl(4) treatment, hepatocyte DNA synthesis and mitosis and serum enzyme levels were similar in p50(-/-) and p50(+/+) mice, and histologic analysis indicated a slight decrease in overall damage in p50(-/-) livers. After injection of Fas antibody, p50(-/-) livers showed an earlier onset of nuclear changes consistent with apoptosis. These data indicate that absence of p50 affects certain protein and gene activation pathways following partial hepatectomy, CCl(4), and Fas treatment but does not impair overall liver regeneration. Interleukin 6 (IL-6) levels were reduced but still adequate to support regeneration. We hypothesize that increased levels of the NF-kappaB p65 subunit in p50(-/-) livers may provide compensation for the absence of p50, thereby allowing normal liver regeneration and repair following liver injury.
Asunto(s)
Regeneración Hepática/fisiología , FN-kappa B/fisiología , Alanina Transaminasa/sangre , Animales , Apoptosis , Tetracloruro de Carbono/farmacología , ADN/biosíntesis , Proteínas de Unión al ADN/metabolismo , Expresión Génica , Hepatectomía/métodos , Proteínas I-kappa B/metabolismo , Inyecciones Intraperitoneales , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Ratones , Ratones Noqueados/genética , FN-kappa B/genética , Isoformas de Proteínas/genética , Isoformas de Proteínas/fisiología , Valores de Referencia , Factor de Transcripción STAT3 , Transactivadores/metabolismo , Receptor fas/farmacologíaRESUMEN
Interleukin-6 null (IL-6-/-) mice have impaired liver regeneration and increased liver necrosis following partial hepatectomy that is corrected with IL-6 treatment. Following acute carbon tetrachloride (CCl(4)) treatment, we found that IL-6-/- mice developed increased hepatocellular injury and defective regeneration with significant blunting of signal transducer-and-activator of transcription protein 3 (STAT3) and nuclear factor-kappaB (NF-kappaB) activation and reduced hepatocyte DNA synthetic and mitotic responses. After CCl(4) treatment, unlike partial hepatectomy, increased hepatocyte apoptosis was noted in IL-6-/- livers. Pretreatment with IL-6 before CCl(4) reduced acute CCl(4) injury and apoptosis and accelerated regeneration in both IL-6+/+ and -/- livers. Repetitive doses of CCl(4) in the presence or absence of phenobarbital resulted in increased injury and fibrosis in IL-6 -/- compared with +/+ livers. After acute and chronic injury, IL-6-/- livers showed the protracted presence of alpha-smooth muscle actin associated with activated stellate cells, indicating a disturbed response in wound healing that progressed to fibrosis. These data provide evidence for an important role for IL-6 in reducing CCl(4)-induced acute and chronic liver injury and fibrosis.
Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas , Interleucina-6/deficiencia , Cirrosis Hepática Experimental/inducido químicamente , Actinas/metabolismo , Animales , Apoptosis , Tetracloruro de Carbono , ADN/biosíntesis , Proteínas de Unión al ADN/metabolismo , Interleucina-6/fisiología , Cinética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mitosis , FN-kappa B/metabolismo , Fenobarbital/administración & dosificación , Factor de Transcripción STAT3 , Transactivadores/metabolismoRESUMEN
The insulin-like growth factor binding protein-1 (IGFBP-1) gene is highly expressed in fetal, perinatal, and regenerating liver. Up-regulation is transcriptionally mediated in regenerating liver and occurs in the first few minutes to hours after partial hepatectomy. In transgenic mice a 970-bp region from -776 to +151 of the IGFBP-1 promoter was sufficient for tissue-specific and induced expression of the gene in fetal and hepatectomized livers. However weak and/or poorly regulated expression in some transgenic lines suggested the existence of other regulatory regions. Here, genomic clones containing large regions 5' of the mouse IGFBP-1 gene sequence were isolated, subcloned, and sequenced. Deoxyribonuclease I (DNaseI) hypersensitivity analyses identified clusters of tissue-specific nuclease-sensitive sites in the promoter region, -100 to -300, -2,300, -3,100, and -5,000 along with other weak sites. After partial hepatectomy, enhanced sensitivity and/or novel sites were detected in the -100/-300, -5,000, and -3,100 regions, the promoter region remaining the most hypersensitive. A subset of these sites was present in fetal and perinatal livers. Novel tissue-specific sites that interacted with C/EBP and hepatic nuclear factor 3 (HNF3) transcription factors were identified in the -3,100 region. A hepatectomy-induced DNA binding complex containing the transcription factor USF1 was identified within the -100 to -300 region of the promoter. These results suggested that a complex array of tissue-specific and hepatic proliferation-induced transcription factors combine to regulate both the proximal promoter and more distal regulatory elements of the IGFBP-1 gene.
Asunto(s)
Regulación del Desarrollo de la Expresión Génica , Proteína 1 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Regeneración Hepática , Hígado/citología , Hígado/metabolismo , Regiones Promotoras Genéticas , Animales , Secuencia de Bases , Carcinoma Hepatocelular , Clonación Molecular , Desoxirribonucleasa I , Feto , Hepatectomía , Humanos , Riñón/metabolismo , Neoplasias Hepáticas , Ratones , Ratones Transgénicos , Datos de Secuencia Molecular , Proteínas Recombinantes/biosíntesis , Secuencias Reguladoras de Ácidos Nucleicos , Mapeo Restrictivo , Alineación de Secuencia , Homología de Secuencia de Ácido Nucleico , Bazo/metabolismo , Especificidad por Sustrato , Transfección , Células Tumorales CultivadasRESUMEN
Automated liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) analysis of >100 tryptic digests carried out on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) separated, Coomassie Blue-stained proteins that were prepared by >50 different laboratories demonstrates that a commercial electrospray/quadrupole ion trap mass spectrometer and the tandem mass correlation algorithm developed by Eng et al. (Am. Soc. Mass Spectrom. 1994, 5, 976-989) provide an extremely robust and facile approach to routine protein identification. By requiring a minimum of two significant matches to peptides that would be predicted to be produced by the protease that was used, low pmol levels of proteins can be identified with high confidence while minimizing the probability of identifying the protease itself and/or the ubiquitous contaminant, keratin. Hence, in only 7% of the digests analyzed was keratin identified and in only 5% of the digests analyzed was the protease itself identified. In contrast, 58% of the analyzed samples were identified and, in many instances, multiple proteins were identified in the same sample. Although the median amount of digest analyzed was 6.1 pmol, the limit of sensitivity (as the instrument is configured with a flow rate of 4 microL/min) appears to be at the 500 fmol level. Since one of the primary reasons for not identifying a sample is that its sequence is not yet in the database searched, the utility of an LC MS/MS approach to protein identification will certainly increase in the future as the sequences of more genomes are completed.
Asunto(s)
Electroforesis en Gel de Poliacrilamida/métodos , Proteínas/aislamiento & purificación , Dodecil Sulfato de Sodio/metabolismo , Espectrometría de Masa de Ion Secundario/métodos , Cromatografía Líquida de Alta Presión/métodos , Bases de Datos Factuales , Hidrólisis , Mapeo Peptídico/métodos , Proteínas/metabolismo , TripsinaRESUMEN
Liver regeneration stimulated by a loss of liver mass leads to hepatocyte and nonparenchymal cell proliferation and rapid restoration of liver parenchyma. Mice with targeted disruption of the interleukin-6 (IL-6) gene had impaired liver regeneration characterized by liver necrosis and failure. There was a blunted DNA synthetic response in hepatocytes of these mice but not in nonparenchymal liver cells. Furthermore, there were discrete G1 phase (prereplicative stage in the cell cycle) abnormalities including absence of STAT3 (signal transducer and activator of transcription protein 3) activation and depressed AP-1, Myc, and cyclin D1 expression. Treatment of IL-6-deficient mice with a single preoperative dose of IL-6 returned STAT3 binding, gene expression, and hepatocyte proliferation to near normal and prevented liver damage, establishing that IL-6 is a critical component of the regenerative response.
Asunto(s)
Interleucina-6/fisiología , Fallo Hepático/etiología , Regeneración Hepática , Hígado/citología , Animales , Ciclina D1 , Ciclinas/biosíntesis , ADN/biosíntesis , ADN/metabolismo , Proteínas de Unión al ADN/metabolismo , Fase G1 , Regulación de la Expresión Génica , Marcación de Gen , Genes Inmediatos-Precoces , Hepatectomía , Interleucina-6/deficiencia , Interleucina-6/genética , Interleucina-6/farmacología , Hígado/metabolismo , Hígado/patología , Fallo Hepático/patología , Ratones , Ratones Endogámicos C57BL , Mitosis , Mutación , Necrosis , Proteínas Oncogénicas/biosíntesis , Proteínas Proto-Oncogénicas c-myc/biosíntesis , Factor de Transcripción STAT3 , Transactivadores/metabolismo , Factor de Transcripción AP-1/biosíntesisRESUMEN
Many cases reported as malignant melanomas arising in benign congenital melanocytic nevi in the neonatal period have not shown evidence of metastases after several years of follow-up. These lesions were probably pathologically misdiagnosed, thus creating a controversy regarding the precise incidence. This article describes the case of an infant with a giant melanocytic nevus simulating malignant melanoma to illustrate the proper criteria for diagnosis of this condition so extensive and unnecessary therapy procedures can be avoided.
Asunto(s)
Melanoma/diagnóstico , Nevo Pigmentado/congénito , Nevo Pigmentado/diagnóstico , Neoplasias Cutáneas/congénito , Neoplasias Cutáneas/diagnóstico , Diagnóstico Diferencial , Humanos , Lactante , Masculino , Melanoma/patología , Nevo Pigmentado/patología , Nevo Pigmentado/cirugía , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/cirugíaRESUMEN
Superelastic mechanical behavior of nitinol alloy orthodontic wires is thought to be the result of a stress induced crystallographic transformation from austenite to martensite. The purpose of the study was to compare the SE mechanical behavior of nitinol wires to stress-induced phase changes. Eight nitinol arch wires having rectangular cross-sections were strained from 0% to 10% in tension with a mechanical testing machine. Load/extension plots were subjectively ranked for SE behavior. X-ray diffraction patterns were collected with and without 6% strain. Without strain, nitinol wires were found to be predominantly austenite with some wires containing a small amount of martensite. When strained 6%, superelastic wires demonstrated a phase transformation from austenite to martensite. XRD patterns were ranked for percent transformation and 110 peak width. Product rankings of the degree of superelasticity were positively correlated with the rank of martensitic transformation (p < 0.05). Superelasticity ranks were negatively correlated with XRD peak width ranks (p < 0.01). Increased peak width indicates greater cold work. A range of superelastic mechanical behavior and martensitic transformation is exhibited by wires currently on the market. Cold work and heat treatments are important variables to be controlled during the manufacture of nitinol products.
Asunto(s)
Aleaciones Dentales/química , Níquel/química , Alambres para Ortodoncia , Titanio/química , Aleaciones/química , Aleaciones Dentales/análisis , Análisis del Estrés Dental , Análisis Diferencial Térmico , Elasticidad , Ensayo de Materiales , Estructura Molecular , Resistencia a la Tracción , Difracción de Rayos XRESUMEN
1. Tyloxapol, trace-labelled (50-100 microCi/animal) with 3H or 14C, was administered intratracheally in a surfactant formulation (EXOSURF Neonatal) to the male rabbit in a total tyloxapol dose of 5 mg/kg. Urine, faeces, expired air, and blood were collected for up to 10 days following tyloxapol administration. 2. Over 5 days, 3H-tyloxapol-related radioactivity in the urine (13.4%) and faeces (27.4%) accounted for a major fraction of the labelled dose. However, urine also contained an additional 13% of the dose as tritiated water. Expired air accounted for only 4.2% of the dose. At the end of the study, an additional 35.6% of the radioactive dose was found in tissues and the carcass, mainly in the lung (27.4%) and to a lesser extent in the liver (2.8%) and kidney (0.4%). Levels of radioactivity in other tissues, including whole blood, were low. 3. Over a separate 10-day study, faecal (30.4%) and renal (9.7%) elimination of 14C-tyloxapol accounted for 40% of the radioactive dose, with expired air accounting for much less (2.7%). At the end of the study, additional radioactivity was recovered from the lung (43.9%) and to a lesser extent from the liver (3.8%) and kidney (0.3%). The half-life for the elimination of total radioactivity from the lung was estimated to be 10-12 days. 4. These data indicate that, following intratracheal administration, tyloxapol and metabolites were retained by the lung, released slowly into the systemic circulation, and eliminated through faecal and renal excretion.
Asunto(s)
Polietilenglicoles/farmacocinética , Tensoactivos/farmacocinética , Animales , Cromatografía Líquida de Alta Presión , Heces/química , Semivida , Intubación Intratraqueal , Masculino , Conformación Molecular , Polietilenglicoles/administración & dosificación , Conejos , Conteo por Cintilación , Espectrofotometría Ultravioleta , Tensoactivos/administración & dosificación , Distribución Tisular , Agua/metabolismoRESUMEN
High dose aprotinin has been used in cardiac surgery (Royston 1987) to reduce post operative bleeding. A low dose aprotinin ie 2000000 KIU in the oxygenator prime, has been also proposed. OBJECTIVE. To evaluate postoperative losses and holomogous blood transfusions, in patients undergoing cardiac surgery treated with low and high dose aprotinin. METHODS AND MATERIALS. Ninety-nine patients, between January and May 1993, have randomized in 3 groups: A, high dose aprotinin; B, low dose aprotinin; C, control. All patients were treated with additional blood saving techniques routinely used in our center. Statistical analysis was performed by means of ANOVA and Tukey Kramer test. MAIN RESULTS. Five patients (3 in group A, 1 each in groups B and C) have been excluded during the trial. The groups resulted omogeneus and comparable. Total blood losses were 372 +/- 159 ml in group A, 401 +/- 178 ml in group B (difference are not significative); the 621 +/- 255 m1 in group C are highly significative. Patients transfused were 18.7% in group C, 10.34% in group A and 6.20% in group B. CONCLUSIONS. Effects of low dose aprotinin are comparable to high dose. Further advantages with low dose are reduction of collateral effects and intolerance phenomena and a better cost benefits ratio.
Asunto(s)
Aprotinina/administración & dosificación , Pérdida de Sangre Quirúrgica/prevención & control , Anciano , Transfusión de Sangre Autóloga , Humanos , Persona de Mediana EdadRESUMEN
This article provided a brief overview of synthetic surfactants and DPPC metabolism, and summarized disposition data on the most widely used synthetic surfactant, CPHT (colfosceril palmitate, hexadecanol, and tyloxapol; Exosurf Neonatal, Burroughs Wellcome Co.). In separate experiments, young male rabbits were given intratracheal administrations of CPHT trace-labeled with either hexadecanol-3-[14C], choline-labeled [14C]DPPC, or [3H]tyloxapol. In mass balance and tissue distribution studies, radioactivity was quantitated in excreta and selected tissues over 5 days. Hexadecanol entered the pathways of intermediary lipid metabolism, via oxidation to palmitic acid, which was then utilized in the synthesis of phospholipids. After 5 days, most of the radiolabeled dose (56%) was distributed throughout the body, with renal (4%) and fecal (2%) excretion being minor routes of elimination compared with expired air (28%). The active component, DPPC, was still retained by the body (72%) after 5 days, having entered the pathways of lipid metabolism to become tissue associated. At this time, the lung and liver each contained approximately 10% of the labeled dose, whereas elimination in excreta (8%) was minimal compared with that in expired air (17%). Tyloxapol and metabolites were retained by the lung, released slowly (t1/2 = 5 to 6 days) into the systemic circulation, and eliminated through fecal (27%) and renal (26%) excretion.
Asunto(s)
Surfactantes Pulmonares/metabolismo , 1,2-Dipalmitoilfosfatidilcolina/análogos & derivados , 1,2-Dipalmitoilfosfatidilcolina/metabolismo , Animales , Alcoholes Grasos/metabolismo , Tasa de Depuración Metabólica , Polietilenglicoles/metabolismo , Surfactantes Pulmonares/síntesis química , Surfactantes Pulmonares/farmacocinética , Tensoactivos/metabolismoRESUMEN
Esophageal replacement remains a challenge. Colon and jejunum provide alternative conduits to replace the lower esophagus when stomach is not suitable. Between 1971 and 1991, 41 patients underwent short-segment interposition of the esophagus with jejunum or colon. Indications were failed antireflux procedures (n = 21), nondilatable stricture (n = 9), achalasia (n = 2), moniliasis (n = 2), Barrett's esophagus with carcinoma in situ (n = 2), hemorrhagic esophagitis after esophagogastrectomy (n = 1), motility disorder (n = 1), instrumental perforation (n = 1), carcinoma (n = 1), and leiomyosarcoma (n = 1). Thirty-one patients (75.6%) had prior surgical procedures. Interposition with colon was performed in 22 patients and with jejunum in 19. Major complications occurred in 45% after colon interposition (10/22) and hospital mortality was 4.5% (1/22). Major complications after jejunal interposition occurred in 31% (6/19) and hospital mortality was 10.5% (2/19). A contained anastomotic leak occurred in 1 patient, perforation of a colon segment in 1, and jejunal graft necrosis in a third. Late functional results in 34 patients with a mean follow-up of 87 months were excellent or good in 26, fair in 5, and poor in 1. Colon interposition failed to improve symptoms in 2 patients with gastrointestinal motility disorders. Six patients underwent manometry and barium food provocation study. Two colon segments and 3 jejunal interpositions were hypoperistaltic or aperistaltic according to manometry. There was 1 case of aperistaltic jejunum with a distended afferent loop. When stomach is not available, successful palliation of swallowing can be accomplished with either jejunum or colon. Surgeons involved in the management of esophageal disease should be familiar with the technical details of both procedures.
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Colon/trasplante , Estenosis Esofágica/cirugía , Esofagectomía/métodos , Reflujo Gastroesofágico/cirugía , Yeyuno/trasplante , Adulto , Anciano , Anastomosis Quirúrgica/métodos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Reoperación , Resultado del TratamientoRESUMEN
The ability of a siderophore-catabolizing bacterium to assimilate ferric ion was examined. While the bacterium utilizes the siderophore deferrioxamine B (DFB) as a carbon source, it was incapable of using the ferric ion analogue (ferrioxamine B) as an iron source. It did, however, assimilate the ferric ion of the chelator ferric nitrilotriacetic acid and of the siderophore ferrirhodotorulic acid (ferriRA). Neither ferriRA nor its deferrated analog (RA), however, were capable of functioning as carbon sources for the bacterium. The microbe thus employs a 'nutritional selectivity' with respect to these two siderophores. That is, it does not use the siderophore it employs as a carbon source (DFB) as an iron source nor does the siderophore utilized as an iron source, i.e. ferriRA, nor its deferrated analog (RA), serve as carbon sources for the organism.
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Bacterias/metabolismo , Deferoxamina/metabolismo , Hierro/metabolismo , Bacterias/crecimiento & desarrollo , Bacterias/aislamiento & purificación , Transporte Biológico , Compuestos Férricos/metabolismo , Radioisótopos de Hierro , Cinética , Microbiología del SueloRESUMEN
Hypokalemia is an electrolyte imbalance that can have serious effects on the patient if not detected early. Therefore, it is important for the nurse to: (1) be aware of those patients at risk for excess potassium loss, (2) monitor those patients' ECG to observe for any changes indicative of hypokalemia, and (3) assess for physical signs and symptoms indicative of hypokalemia. Early detection of hypokalemia and early intervention will prevent potential catastrophic events.
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Electrocardiografía , Hipopotasemia/fisiopatología , Humanos , Hipopotasemia/tratamiento farmacológico , Hipopotasemia/enfermería , Infusiones Intravenosas , Planificación de Atención al Paciente , Potasio/administración & dosificación , Potasio/uso terapéuticoRESUMEN
A rapid and sensitive high-performance liquid chromatographic procedure was developed for the analysis of the new, long-acting neuromuscular blocker doxacurium in the plasma and urine of dog and man and in the bile of dog. Samples were prepared on solid-phase extraction cartridges containing a methyl (C1) bonded phase and were chromatographed on a 15 cm reversed-phase column (C1) using a mobile phase of 0.05 M monobasic potassium phosphate-acetonitrile (30:70, v/v). The compound was detected at 210 nm with a lower limit of quantitation of 10 ng/ml. An inter-assay accuracy of 90-92% was obtained for the analysis of the drug from biological fluids. The method was applied to studies of doxacurium after intravenous administration to dog and man.