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1.
Bull Entomol Res ; 109(5): 695-700, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30971323

RESUMEN

Colorado potato beetle (Leptinotarsa decemlineata, Say) is the main pest of Solanaceae and its survival is mainly dependent on the carbohydrate digestion. Characterizing the gut enzymes may help us with finding effective inhibitors for plant protection. Activity measurements revealed that gut extracts contain α- and ß-glucosidase in addition to α-amylase. For larvae, amylase activity was detected only in gut saturated with nutrients. Leptinotarsa decemlineata α-amylase (LDAmy) had optimum pH of 6.0 and was active under 30-40°C temperature measured on a selective α-amylase substrate, 2-chloro-4-nitrophenyl-4-O-α-D-galactopyranosyl-maltoside. HPLC analysis demonstrated dimer, trimer, and tetramer reducing end amylolytic products from 2-chloro-4-nitrophenyl-maltoheptaoside substrate in similar ratio than that of during porcine pancreatic α-amylase (PPA) catalyzed hydrolysis. The 4,6-O-benzylidene-modified substrate (BzG7PNP) is very stable toward hydrolysis by exo-glycosidases, therefore is very useful to monitor the digestion catalyzed by α-amylases exclusively. Similarly to PPA active site, three glycon and two aglycon binding sites are suggested for LDAmy based on the pattern of early hydrolysis products of BzG7PNP. The observed similarity between LDAmy and PPA raises the possibility of using known inhibitors of mammalian α-amylases to protect the potato plant from attack of Colorado potato beetle.


Asunto(s)
Metabolismo de los Hidratos de Carbono , Escarabajos/enzimología , Sistema Digestivo/enzimología , Animales , Escarabajos/metabolismo , Concentración de Iones de Hidrógeno , Larva/enzimología , Larva/metabolismo , Temperatura , alfa-Amilasas , alfa-Glucosidasas , beta-Glucosidasa
2.
Anal Chem ; 84(14): 6061-9, 2012 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-22681761

RESUMEN

Ion beam analysis (IBA) is a cluster of techniques including Rutherford and non-Rutherford backscattering spectrometry and particle-induced X-ray emission (PIXE). Recently, the ability to treat multiple IBA techniques (including PIXE) self-consistently has been demonstrated. The utility of IBA for accurately depth profiling thin films is critically reviewed. As an important example of IBA, three laboratories have independently measured a silicon sample implanted with a fluence of nominally 5 × 10(15) As/cm(2) at an unprecedented absolute accuracy. Using 1.5 MeV (4)He(+) Rutherford backscattering spectrometry (RBS), each lab has demonstrated a combined standard uncertainty around 1% (coverage factor k = 1) traceable to an Sb-implanted certified reference material through the silicon electronic stopping power. The uncertainty budget shows that this accuracy is dominated by the knowledge of the electronic stopping, but that special care must also be taken to accurately determine the electronic gain of the detection system and other parameters. This RBS method is quite general and can be used routinely to accurately validate ion implanter charge collection systems, to certify SIMS standards, and for other applications. The generality of application of such methods in IBA is emphasized: if RBS and PIXE data are analysed self-consistently then the resulting depth profile inherits the accuracy and depth resolution of RBS and the sensitivity and elemental discrimination of PIXE.

3.
Infection ; 38(3): 159-64, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20232107

RESUMEN

BACKGROUND: The prevalence of hospital-acquired Methicillin-resistant Staphylococcus aureus (MRSA) infections shows a huge variety across Europe. Some countries reported a reduction in MRSA frequency, while in others countries increasing MRSA rates have been observed. To reduce the spread of MRSA in the healthcare setting, a sufficient MRSA management is essential. In order to reflect the MRSA management across Europe, MRSA prevention policies were surveyed in ten countries. MATERIALS AND METHODS: The survey was performed by questionnaires in European intensive care units (ICUs) and surgical departments (SDs) in 2004. Questionnaires asked for availability of bedside alcohol hand-disinfection, isolation precautions, decolonization and screening methods. The study was embedded in the Hospital in Europe Link for Infection Control through Surveillance (HELICS) Project, a European collaboration of national surveillance networks. HELICS was initiated in order to harmonize the national surveillance activities in the individual countries. Therefore, HELICS participants developed surveillance modules for nosocomial infections in ICUs and for surgical site infections (SSI). The coordination of this surveillance has now been transferred to the European Centre for Disease Prevention and Control (ECDC). RESULTS: A total of 526 ICUs and 223 SDs from ten countries sent data on organisational characteristics and policies, demonstrating wide variations in care. Substantial variation existed in availability of bedside alcohol hand-disinfection, which was much higher in participating ICUs rather than in SDs (86 vs. 59%). Surveillance cultures of contact patients were obtained in approximately three-fourths of all SDs (72%) and ICUs (75%). Countries with decreasing MRSA proportions showed especially strict implementation of various prevention measures. CONCLUSION: The data obtained regarding MRSA prevention measures should stimulate infection control professionals to pursue further initiatives. Particularly, the vigorous MRSA management in countries with decreasing MRSA proportions should encourage hospitals to implement preventive measures in order to reduce the spread of MRSA.


Asunto(s)
Infección Hospitalaria/epidemiología , Infección Hospitalaria/prevención & control , Control de Infecciones/métodos , Staphylococcus aureus Resistente a Meticilina , Vigilancia de la Población/métodos , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/prevención & control , Infección Hospitalaria/microbiología , Europa (Continente)/epidemiología , Humanos , Unidades de Cuidados Intensivos/estadística & datos numéricos , Infecciones Estafilocócicas/microbiología
4.
J Hosp Infect ; 71(1): 74-80, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18723245

RESUMEN

In 2004, a secure web-based national nosocomial infection surveillance system was established in Hungary. The system, named NNSR (Nemzeti Nosocomiális Surveillance Rendszer), is based on the US National Nosocomial Infection Surveillance System (NNIS). Surgical procedures, definitions, surveillance methodology and patient risk indices are those established by NNIS. In this paper, we present the results of the first two years of the surgical patient component of our system. During this period, 41 hospitals participated and selected 11 surgical procedures for surveillance. Altogether 15812 procedures were surveyed and 360 resulting surgical site infections (SSI) were recorded. The overall SSI rate was 2.27%. The most commonly selected procedures and corresponding SSI rates were caesarean section (1.31%), herniorrhaphy (2.09%), cholecystectomy (1.52%) and hip replacement (2.91%). Standardised infection ratios (SIR) were calculated for chosen surgical procedures in order to compare against NNIS published rates. SSI rates for colonic surgery, caesarean section and mastectomy were lower than expected according to the NNIS data but higher for cholecystectomy, herniorrhaphy and hip prosthesis infection rates. We intend to recruit more participating hospitals, leading to a robust national database that can be used to target infection control interventions for patients in Hungary.


Asunto(s)
Infección Hospitalaria/epidemiología , Vigilancia de la Población , Infección de la Herida Quirúrgica/epidemiología , Humanos , Hungría/epidemiología , Incidencia , Control de Infecciones
5.
J Hosp Infect ; 71(1): 66-73, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18799236

RESUMEN

This study was performed to evaluate associations between organisational characteristics, routine practices and the incidence densities of central venous catheter-associated bloodstream infections (CVC-BSI rates) in European intensive care units (ICUs) as part of the HELICS project (Hospitals in Europe Link for Infection Control through Surveillance). Questionnaires were sent to ICUs participating in the national nosocomial infection surveillance networks in 2004. The national networks were asked for the CVC-BSI rates of the ICUs participating for the time period 2003--2004. Univariate and multivariate risk factor analyses were performed to identify which practices had the greatest impact on CVC-BSI rates. A total of 526 ICUs from 10 countries sent data on organisational characteristics and practices, demonstrating wide variation in care. CVC-BSI rates were also provided for 288 ICUs from five countries. This made it possible to include 1383444 patient days, 969897 CVC days and 1935 CVC-BSI cases in the analysis. Adjusted logistic regression analysis showed that the categorical variables of country [odds ratio (OR) varying per country from OR: 2.3; 95% confidence interval (CI): 0.5-10.2; to OR: 12.8; 95% CI: 4.4-37.5; in reference to the country with the lowest CVC-BSI rates] and type of hospital 'university' (OR: 2.08; 95% CI: 1.02-4.25) were independent risk factors for high CVC-BSI rates. Substantial variation existed in CVC-BSI prevention activities, surveillance methods and estimated CVC-BSI rates among the European countries. Differences in cultural, social and legal perspectives as well as differences between healthcare systems are crucial in explaining these differences.


Asunto(s)
Bacteriemia/epidemiología , Infecciones Relacionadas con Catéteres/epidemiología , Infección Hospitalaria/epidemiología , Control de Infecciones/métodos , Bacteriemia/prevención & control , Infecciones Relacionadas con Catéteres/prevención & control , Infección Hospitalaria/prevención & control , Europa (Continente)/epidemiología , Hospitales Universitarios/estadística & datos numéricos , Humanos , Incidencia , Unidades de Cuidados Intensivos/estadística & datos numéricos , Oportunidad Relativa , Vigilancia de Guardia
6.
J Hosp Infect ; 102(3): 267-276, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30529703

RESUMEN

BACKGROUND: Surveillance of surgical site infections (SSIs) is a core component of effective infection control practices, though its impact has not been quantified on a large scale. AIM: To determine the time-trend of SSI rates in surveillance networks. METHODS: SSI surveillance networks provided procedure-specific data on numbers of SSIs and operations, stratified by hospitals' year of participation in the surveillance, to capture length of participation as an exposure. Pooled and procedure-specific random-effects Poisson regression was performed to obtain yearly rate ratios (RRs) with 95% confidence intervals (CIs), and including surveillance network as random intercept. FINDINGS: Of 36 invited networks, 17 networks from 15 high-income countries across Asia, Australia and Europe participated in the study. Aggregated data on 17 surgical procedures (cardiovascular, digestive, gynaecological-obstetrical, neurosurgical, and orthopaedic) were collected, resulting in data concerning 5,831,737 operations and 113,166 SSIs. There was a significant decrease in overall SSI rates over surveillance time, resulting in a 35% reduction at the ninth (final) included year of surveillance (RR: 0.65; 95% CI: 0.63-0.67). There were large variations across procedure-specific trends, but strong consistent decreases were observed for colorectal surgery, herniorrhaphy, caesarean section, hip prosthesis, and knee prosthesis. CONCLUSION: In this large, international cohort study, pooled SSI rates were associated with a stable and sustainable decrease after joining an SSI surveillance network; a causal relationship is possible, although unproven. There was heterogeneity in procedure-specific trends. These findings support the pivotal role of surveillance in reducing infection rates and call for widespread implementation of hospital-based SSI surveillance in high-income countries.


Asunto(s)
Monitoreo Epidemiológico , Control de Infecciones/métodos , Cooperación Internacional , Infección de la Herida Quirúrgica/epidemiología , Infección de la Herida Quirúrgica/prevención & control , Asia/epidemiología , Australia/epidemiología , Europa (Continente)/epidemiología , Humanos , Incidencia , Estudios Retrospectivos
7.
Stem Cell Rev Rep ; 14(2): 189-199, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29305755

RESUMEN

Over the past decade different stem cell (SC) based approaches were tested to treat Duchenne Muscular Dystrophy (DMD), a lethal X-linked disorder caused by mutations in dystrophin gene. Despite research efforts, there is no curative therapy for DMD. Allogeneic SC therapies aim to restore dystrophin in the affected muscles; however, they are challenged by rejection and limited engraftment. Thus, there is a need to develop new more efficacious SC therapies. Chimeric Cells (CC), created via ex vivo fusion of donor and recipient cells, represent a promising therapeutic option for tissue regeneration and Vascularized Composite Allotransplantation (VCA) due to tolerogenic properties that eliminate the need for lifelong immunosuppression. This proof of concept study tested feasibility of myoblast fusion for Dystrophin Expressing. Chimeric Cell (DEC) therapy through in vitro characterization and in vivo assessment of engraftment, survival, and efficacy in the mdx mouse model of DMD. Murine DEC were created via ex vivo fusion of normal (snj) and dystrophin-deficient (mdx) myoblasts using polyethylene glycol. Efficacy of myoblast fusion was confirmed by flow cytometry and dystrophin immunostaining, while proliferative and myogenic differentiation capacity of DEC were assessed in vitro. Therapeutic effect after DEC transplant (0.5 × 106) into the gastrocnemius muscle (GM) of mdx mice was assessed by muscle functional tests. At 30 days post-transplant dystrophin expression in GM of injected mdx mice increased to 37.27 ± 12.1% and correlated with improvement of muscle strength and function. Our study confirmed feasibility and efficacy of DEC therapy and represents a novel SC based approach for treatment of muscular dystrophies.


Asunto(s)
Distrofina/metabolismo , Distrofia Muscular de Duchenne/metabolismo , Mioblastos/citología , Mioblastos/metabolismo , Células Madre/citología , Células Madre/metabolismo , Animales , Proliferación Celular/genética , Proliferación Celular/fisiología , Células Cultivadas , Citometría de Flujo , Ratones , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/genética
8.
Artículo en Inglés | MEDLINE | ID: mdl-29163939

RESUMEN

BACKGROUND: Infections with carbapenem-resistant Enterobacteriaceae (CRE) are increasingly being reported from patients in healthcare settings. They are associated with high patient morbidity, attributable mortality and hospital costs. Patients who are "at-risk" may be carriers of these multidrug-resistant Enterobacteriaceae (MDR-E).The purpose of this guidance is to raise awareness and identify the "at-risk" patient when admitted to a healthcare setting and to outline effective infection prevention and control measures to halt the entry and spread of CRE. METHODS: The guidance was created by a group of experts who were functioning independently of their organisations, during two meetings hosted by the European Centre for Disease Prevention and Control. A list of epidemiological risk factors placing patients "at-risk" for carriage with CRE was created by the experts. The conclusions of a systematic review on the prevention of spread of CRE, with the addition of expert opinion, were used to construct lists of core and supplemental infection prevention and control measures to be implemented for "at-risk" patients upon admission to healthcare settings. RESULTS: Individuals with the following profile are "at-risk" for carriage of CRE: a) a history of an overnight stay in a healthcare setting in the last 12 months, b) dialysis-dependent or cancer chemotherapy in the last 12 months, c) known previous carriage of CRE in the last 12 months and d) epidemiological linkage to a known carrier of a CRE.Core infection prevention and control measures that should be considered for all patients in healthcare settings were compiled. Preliminary supplemental measures to be implemented for "at-risk" patients on admission are: pre-emptive isolation, active screening for CRE, and contact precautions. Patients who are confirmed positive for CRE will need additional supplemental measures. CONCLUSIONS: Strengthening the microbiological capacity, surveillance and reporting of new cases of CRE in healthcare settings and countries is necessary to monitor the epidemiological situation so that, if necessary, the implemented CRE prevention strategies can be refined in a timely manner. Creating a large communication network to exchange this information would be helpful to understand the extent of the CRE reservoir and to prevent infections in healthcare settings, by applying the principles outlined here.This guidance document offers suggestions for best practices, but is in no way prescriptive for all healthcare settings and all countries. Successful implementation will result if there is local commitment and accountability. The options for intervention can be adopted or adapted to local needs, depending on the availability of financial and structural resources.

9.
Clin Microbiol Infect ; 21(12): 1067-71, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26369604

RESUMEN

Reasons for a successful or unsuccessful implementation of infection prevention and control (IPC) guidelines are often multiple and interconnected. This article reviews key elements from the national to the individual level that contribute to the success of the implementation of IPC measures and gives perspectives for improvement. Governance approaches, modes of communication and formats of guidelines are discussed with a view to improve collaboration and transparency among actors. The culture of IPC influences practices and varies according to countries, specialties and healthcare providers. We describe important contextual aspects, such as relationships between actors and resources and behavioural features including professional background or experience. Behaviour change techniques providing goal-setting, feedback and action planning have proved effective in mobilizing participants and may be key to trigger social movements of implementation. The leadership of international societies in coordinating actions at international, national and institutional levels using multidisciplinary approaches and fostering collaboration among clinical microbiology, infectious diseases and IPC will be essential for success.


Asunto(s)
Control de Infecciones/métodos , Control de Infecciones/organización & administración , Infección Hospitalaria/prevención & control , Instituciones de Salud , Humanos , Guías de Práctica Clínica como Asunto , Sociedades Médicas
10.
Clin Microbiol Infect ; 21(12): 1047-51, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26417851

RESUMEN

Hand hygiene is considered to be the most effective way of preventing microbial transmission and healthcare-associated infections. The use of alcohol-based hand rubs (AHRs) is the reference standard for effective hand hygiene. AHR consumption is a valuable surrogate parameter for hand hygiene performance, and it can be easily tracked in the healthcare setting. AHR availability at the point of care ensures access to optimal agents, and makes hand hygiene easier by overcoming barriers such as lack of AHRs or inconvenient dispenser locations. Data on AHR consumption and availability at the point of care in European hospitals were obtained as part of the Prevention of Hospital Infections by Intervention and Training (PROHIBIT) study, a framework 7 project funded by the European Commission. Data on AHR consumption were provided by 232 hospitals, and showed median usage of 21 mL (interquartile range (IQR) 9-37 mL) per patient-day (PD) at the hospital level, 66 mL/PD (IQR 33-103 mL/PD) at the intensive-care unit (ICU) level, and 13 mL/PD (IQR 6-25 mL/PD) at the non-ICU level. Consumption varied by country and hospital type. Most ICUs (86%) had AHRs available at 76-100% of points of care, but only approximately two-thirds (65%) of non-ICUs did. The availability of wall-mounted and bed-mounted AHR dispensers was significantly associated with AHR consumption in both ICUs and non-ICUs. The data show that further improvement in hand hygiene behaviour is needed in Europe. To what extent factors at the national, hospital and ward levels influence AHR consumption must be explored further.


Asunto(s)
Antiinfecciosos Locales/administración & dosificación , Desinfección de las Manos/métodos , Desinfectantes para las Manos/administración & dosificación , Infección Hospitalaria/prevención & control , Europa (Continente) , Encuestas Epidemiológicas , Hospitales/estadística & datos numéricos , Humanos , Sistemas de Atención de Punto/estadística & datos numéricos
11.
Surgery ; 84(4): 563-72, 1978 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-694742

RESUMEN

The clinical course of 29 patients bearing 36 renal artery aneurysms was reviewed. The majority of the lesions (30 of 36 or 83%) were detected incidentally in the course of angiographic examination, mostly in the study of peripheral atherosclerotic arterial disease. Twenty-five lesions 2.0 cm or less in diameter, treated conservatively and observed during a period of time of from 1 to 17 years, remained clinically silent. In 10 patients (with 11 lesions) surgical treatment was employed. For eight patients the surgical treatment consisted of reconstructive excision and repair, with excellent results in all cases but one for a period of observation of from 1 to 17 years. In one patient aneurysmal dilatation of a vein bypass graft resulted in nephrectomy 2 years following operation. In the remaining two patients nephrectomy was required. Unless hypertension or pregnancy complicates the clinical picture, renal arterial aneurysms 1.5 cm or less in diameter can be observed safely by periodic angiography. Surgical repair of an aneurysm is recommended regardless of size if pregnancy cannot be avoided and hypertension is uncontrolled, and in aneurysms 1.5 cm or less in diameter which show an increase in size. A number of reconstructive vascular procedures have proved successful. Ex vivo repair may be an organ-saving technical aid.


Asunto(s)
Aneurisma/cirugía , Arteria Renal , Adulto , Anciano , Aneurisma/diagnóstico , Aneurisma/diagnóstico por imagen , Femenino , Humanos , Masculino , Métodos , Persona de Mediana Edad , Pronóstico , Radiografía , Arteria Renal/diagnóstico por imagen , Arteria Renal/cirugía
12.
Surgery ; 88(6): 833-45, 1980 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-7444764

RESUMEN

The clinical course of 225 patients who had experienced 309 arterial embolic episodes was reviewed with special reference to the problems of the identification of the source of embolization, multiplicity of involvement, significance of recurrence, and the effects of some therapeutic means, including anticoagulation, on the early and late results. The most common source of embolization was cardiac (in 85% of the cases). Persistent search, at times by complex diagnostic methods, uncovered the origin in all but 11% of the cases. Within a range of 8 hours to 7 days the effect of delayed treatment had a linear relationship to the severity of ischemic changes and the deterioration of favorable results. Angiography was helpful and often essential in the diagnosis of visceral embolism and in differentiating local thrombosis from embolism in the periphery. Recurrent embolization was common (in 28% of the cases), was often multiple, and had a grave prognosis. Permanent anticoagulant therapy, preferably with but even without the removal of the source of embolization, reduced the rate of recurrence and, in general, reduced early and late morbidity and mortality rates.


Asunto(s)
Embolia/diagnóstico , Adulto , Anciano , Angiografía , Anticoagulantes/uso terapéutico , Aortografía , Embolia/tratamiento farmacológico , Embolia/cirugía , Femenino , Humanos , Persona de Mediana Edad , Pronóstico , Recurrencia , Factores de Tiempo
13.
Mutat Res ; 111(2): 145-59, 1983 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-6415474

RESUMEN

The effect of storage on MMS-induced recessive lethals in the zeste-white (3A1-3C2) and the maroon-like (18F4-20F) regions was studied by complementation analysis. (1) Without any exception, all 52 mutants (from unstored spermatozoa) mapped in the zeste-white region were restricted to single complementation units. Furthermore, none of an additional 15 lethals, sampled from sperm that had been stored in females for 9-12 days, was associated with a deletion. (2) Of 34 mutations induced by 8.5 X 10(-2) mM MMS in the maroon-like (mal) region, 4 spanned 2 or more complementation units, and thus are considered to be deletions. A high dose of 2.5 mM MMS provided 55 lethals for analysis of which 4 were deletions. There was no evidence for any difference in the frequency of deletions as the MMS concentration was enhanced from 8.5 X 10(-2) mM to 2.5 mM. However, with storage, 47.1% lethals (16 of 34 mutants induced by 2.5 mM MMS) mapped in the mal region were found to involve large structural changes. (3) A high proportion of double mutants in both the zeste-white (z w) and the maroon-like regions was found among the chromosomes analyzed. These double mutants have one lethal positioned within the region studied and the other outside it. Clearly, the proportion of double mutants increased with dose, from 6.3 to 41.7% in z w and from 14.7 to 61.8% in the mal section. Apurinic sites in DNA reacted with MMS are considered as the likely primary lesions responsible for the storage effect on MMS-induced recessive lethals in the mal region. Thus, the ability of MMS to produce delayed deletion lethals seems to correlate with preference for alkylation of base nitrogens. An interesting aspect for further analysis is the apparent infrequency in the zeste-white region of alkylation-induced chromosomal breakage, as observed by various investigators for MMS, EMS and MNNG.


Asunto(s)
Drosophila melanogaster/genética , Genes Letales/efectos de los fármacos , Genes Recesivos/efectos de los fármacos , Metilmetanosulfonato/toxicidad , Cromosoma X/efectos de los fármacos , Alelos , Animales , Deleción Cromosómica , Cruzamientos Genéticos , ADN/genética , Relación Dosis-Respuesta a Droga , Drosophila melanogaster/efectos de los fármacos , Estabilidad de Medicamentos , Femenino , Prueba de Complementación Genética , Masculino , Espermatozoides/fisiología
14.
Struct Dyn ; 1(3): 034301, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-26798776

RESUMEN

We report measurements of the transient structural response of weakly photo-excited thin films of BiFeO3, Pb(Zr,Ti)O3, and Bi and time-scales for interfacial thermal transport. Utilizing picosecond x-ray diffraction at a 1.28 MHz repetition rate with time resolution extending down to 15 ps, transient changes in the diffraction angle are recorded. These changes are associated with photo-induced lattice strains within nanolayer thin films, resolved at the part-per-million level, corresponding to a shift in the scattering angle three orders of magnitude smaller than the rocking curve width and changes in the interlayer lattice spacing of fractions of a femtometer. The combination of high brightness, repetition rate, and stability of the synchrotron, in conjunction with high time resolution, represents a novel means to probe atomic-scale, near-equilibrium dynamics.

16.
Dis Colon Rectum ; 35(6): 574-7; discussion 577-8, 1992 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-1587176

RESUMEN

Thirty patients treated with combination chemotherapy (CT) and radiation therapy (RT) for anal canal carcinoma were reviewed retrospectively to analyze the results of abdominoperineal resection (APR) for treatment failures. Mean follow-up was 34.9 months. Twenty-four patients had squamous carcinomas, and six had cloacogenic carcinomas. Twenty-five had negative inguinal lymph nodes, and five had positive inguinal lymph nodes. The group received 5-fluorouracil, mitomycin C, and 30 to 50 Gy of RT. Biopsy was obtained at six weeks posttherapy. Seventeen of 22 patients (77 percent) with primary tumors of less than 5 cm and negative nodes were disease free at 37 months post-CT-RT. None of the seven patients with primary tumors of greater than 5 cm or positive nodes were free of disease. APR was done for positive biopsy in eight patients and for local recurrence (disease detected after six months of treatment) in one patient. Eight of nine patients who had APR died of disease (mean, 20 months), and one of nine died of other causes. A review of published series, including our data, reveals 24 cases of APR post-CT-RT for positive biopsy, with 17 of 24 (71 percent) dead of disease within three years. APR for CT-RT failures has a poor prognosis. Future protocols may determine whether further CT-RT will improve survival. APR for palliation should always remain an option.


Asunto(s)
Neoplasias del Ano/cirugía , Carcinoma de Células Escamosas/cirugía , Carcinoma de Células Transicionales/cirugía , Abdomen/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias del Ano/tratamiento farmacológico , Neoplasias del Ano/patología , Neoplasias del Ano/radioterapia , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/radioterapia , Carcinoma de Células Transicionales/tratamiento farmacológico , Carcinoma de Células Transicionales/patología , Carcinoma de Células Transicionales/radioterapia , Terapia Combinada , Femenino , Humanos , Ganglios Linfáticos/patología , Masculino , Persona de Mediana Edad , Perineo/cirugía , Pronóstico , Estudios Retrospectivos
17.
Dis Colon Rectum ; 32(2): 149-52, 1989 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2783671

RESUMEN

The case of a 60-year-old man with massive lower intestinal bleeding, secondary to erosion of an abnormally large submucosal muscular artery in the ascending colon, is reported. The bleeding site was localized by angiography. The clinicopathologic presentation of this case is identical to Dieulafoy's disease, which occurs almost exclusively in the stomach. Three similar patients with lesions also located in the ascending colon have been reported in the English medical literature.


Asunto(s)
Colon/irrigación sanguínea , Enfermedades del Colon/etiología , Hemorragia Gastrointestinal/etiología , Arterias/anomalías , Colon/patología , Humanos , Mucosa Intestinal/patología , Masculino , Persona de Mediana Edad
18.
Phys Rev Lett ; 88(15): 157202, 2002 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-11955216

RESUMEN

The domain structure of an antiferromagnetic superlattice is studied. Synchrotron Mössbauer and polarized neutron reflectometric maps show micrometer-size primary domain formation as the external field decreases from saturation to remanence. A secondary domain state consisting mainly of at least 1 order of magnitude larger domains is created when a small field along the layer magnetizations induces a bulk-spin-flop transition. The domain-size distribution is reproducibly dependent on the magnetic prehistory. The condition for domain coarsening is shown to be the equilibrium of the external field energy with the anisotropy energy.

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