RESUMEN
We discuss the calculation of crystal-field splittings using Wannier functions and show how contributions to the crystal-field splitting that are due to hybridization with different ligand states can be separated from the bare Coulomb contribution by constructing sets of Wannier functions incorporating different levels of hybridization. We demonstrate this method using SrVO3 as a generic example of a transition metal oxide. We then calculate trends in the crystal-field splitting for two series of hypothetical tetragonally distorted perovskite oxides and discuss the relation between the calculated 'electrostatic' contribution to the crystal field and the simple point charge model. Finally, we apply our method to the charge disproportionated 5d electron system CsAuCl3. The proposed procedure elucidates the way in which the negative charge transfer energy in this material leads to a reversal of the p-d ligand contribution to the crystal-field splitting such that the eg states of the nominally Au(3+) cation are energetically lower than the corresponding t2g states.
RESUMEN
A randomized surgical adjuvant trial in 242 evaluable patients with T1-3a, N0-1, and M0 breast cancer was initiated 4 years ago. The well-tolerated, oral combination chemotherapy with six cycles of Leukeran plus methotrexate plus fluorouracil (LMF) plus repeated BCG skin scarifications was used. After 4 years, the following results were seen: (1) significant increase of relapse-free (RFS) and also overall survival (S) in both pre- and postmenopausal node-negative patients versus surgical controls (RFS 91.1 vs. 701%, P = 0.003; S 96 vs. 88%, P = 0.03); (2) no significant increase of RFS or S in pre- and postmenopausal node-positive patients versus surgical controls (RFS 50.1 versus 44%, P = 0.49; S 70 versus 68 %, P = 0.9, respectively); (3) Patients receiving greater than 90% of the planned LMF dose showed significantly better survival after 4 years; and (4) Nonrandomized comparison with concurrent Swiss adjuvant studies with LMF alone indicate no beneficial or harmful effect of BCG skin scarifications in addition to the six-cycle LMF.
Asunto(s)
Neoplasias de la Mama/terapia , Clorambucilo/uso terapéutico , Fluorouracilo/uso terapéutico , Metotrexato/uso terapéutico , Neoplasias de la Mama/cirugía , Ensayos Clínicos como Asunto , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Humanos , Inmunoterapia , Metástasis Linfática , Menopausia , Mycobacterium bovis/inmunologíaRESUMEN
This paper describes two solutions for systematic measurement of surface elevation that can be used for both profile and surface reconstructions for quantitative fractography case studies. The first one is developed under Khoros graphical interface environment. It consists of an adaption of the almost classical area matching algorithm, that is based on cross-correlation operations, to the well-known method of parallax measurements from stereo pairs. A normalization function was created to avoid false cross-correlation peaks, driving to the true window best matching solution at each region analyzed on both stereo projections. Some limitations to the use of scanning electron microscopy and the types of surface patterns are also discussed. The second algorithm is based on a spatial correlation function. This solution is implemented under the NIH Image macro programming, combining a good representation for low contrast regions and many improvements on overall user interface and performance. Its advantages and limitations are also presented.
Asunto(s)
Algoritmos , Procesamiento de Imagen Asistido por Computador/métodos , Microscopía Electrónica de Rastreo/métodos , Aleaciones/análisis , Aleaciones/química , Aluminio/análisis , Aluminio/química , Fenómenos Químicos , Química Física , Microcomputadores , Programas InformáticosRESUMEN
Most ulcers of the lower limbs are caused by existing chronic venous insufficiency. Later on, true social and professional problems will arise, with serious economic and psychological consequences not only for the patient himself, but for the community as well, such as huge medical costs--hence the importance of prevention and treatment, which must in no case be purely symptomatic. The ligation of the arch and of the perforating veins and stripping of the affected vein are part of the classical management of varices. These procedures can may prove to be virtually impossible in case of chronic venous insufficiency, if the patient also presents with subcutaneous liposclerosis or atrophy in an already pregangrenous skin. This preulcerous stage can be aggravated later on if the requirements for surgical repair are not met. Necrosis can then occur, if too aggressive surgery directly or indirectly injures the microcirculatory system of the damaged skin. Omitted or undesirable acts are dangerous at the stage of trophic disorders and surgery may fail to reach its aim, which of course would be to definitively and quickly eliminate the varicose disease.
Asunto(s)
Várices/complicaciones , Várices/cirugía , Insuficiencia Venosa/complicaciones , Insuficiencia Venosa/cirugía , Atrofia/etiología , Atrofia/cirugía , Procedimientos Quirúrgicos Dermatologicos , Humanos , Piel/patología , Trasplante de Piel , Úlcera Varicosa/cirugíaRESUMEN
Indications and methods of inferior vena cava interruption in the management of recurrent pulmonary embolism are discussed. The results of a collected series are analyzed with special regard to the partial interruption technique using the Adams and de Weese clip. Five of our own cases, followed up 1 year postoperatively, are presented.
Asunto(s)
Embolia Pulmonar/prevención & control , Vena Cava Inferior/cirugía , Anciano , Constricción/métodos , Femenino , Estudios de Seguimiento , Humanos , Masculino , RecurrenciaRESUMEN
In many of the increasing number of primary or secondary calotte defects resulting from traumatic cranial injuries, plastic reconstruction of the cranium is required. Between 1965 and 1975 in the Surgical Department of Lucerne's Canton Hospital 73 posttraumatic defects of the cranium were repaired. In 69 cases autoplastic transplants and in 4 cases alloplastic transplants were used. The calotte plate (Elliot and Scott), pieces of pelvic bone (Converse), rib (Longacre and De Stefano), as well as costal cartilage (Peer) provided autoplastic material. Alloplasty for the cranium was carried out only in selected cases where special indications were present. Our results in the selection of autologous transplants for the reconstruction of secondary cranial defects is discussed and the surgical procedure is presented.
Asunto(s)
Trasplante Óseo , Cráneo/cirugía , Adolescente , Adulto , Factores de Edad , Cartílago/trasplante , Niño , Humanos , Metacrilatos , Prótesis e Implantes , Reimplantación , Costillas/trasplante , Cráneo/lesiones , Conservación de Tejido , Trasplante Autólogo/métodosRESUMEN
In a prospective randomized double-blind study, the risk of heparin-induced intra- or postoperative hemorrhage in prophylaxis of thromboembolism was studied. 500 general surgical patients were divided into 2 groups; group A receiving a reduced portion of heparin (2 X 2500 IU) in combination with 0.5 mg dihydroergotamine (DHE) was compared to group B with conventional low dose heparin regimen (2 X 5000 IU) with regard to postoperative wound hematomas and reoperation for hematoma. After prophylaxis with heparin dihydroergotamine 2500 wound hematoma and reoperation for hematoma are shown to be reduced in a significant way (p = 0.03).
Asunto(s)
Dihidroergotamina/administración & dosificación , Hemorragia/prevención & control , Heparina de Bajo-Peso-Molecular , Heparina/administración & dosificación , Procedimientos Quirúrgicos Operativos , Tromboembolia/prevención & control , Adulto , Anciano , Método Doble Ciego , Combinación de Medicamentos/administración & dosificación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/prevención & control , Estudios Prospectivos , Distribución Aleatoria , RiesgoRESUMEN
In this paper is presented the case of a 27 year old woman in whom a congenital duplication of the distal ileum led to a massive hemorrhage. Heterotopic gastric mucosa was found in the ileal lesion and ulcer formation histologically proven. This case shows that congenital lesions of this sort may not come to the attention of the pediatrician or pediatric surgeon but become the concern of the surgeon in adult life.
Asunto(s)
Hemorragia Gastrointestinal/etiología , Íleon/anomalías , Anomalías Múltiples , Adulto , Anomalías Congénitas/complicaciones , Femenino , Hemorragia Gastrointestinal/diagnóstico por imagen , Hemorragia Gastrointestinal/patología , Humanos , Íleon/diagnóstico por imagen , Íleon/patología , Lactante , Divertículo Ileal/complicaciones , Divertículo Ileal/diagnóstico , RadiografíaRESUMEN
During the past 7 years 45 patients have been operated upon using the Childs-Phillips method. Of those, 37 were subsequently examined for the study--7 patients had died in the meantime. None of the deaths occurred as a direct result of transmesenteric small-bowel plication. An early recurrence of intestinal obstruction occurred in 4.4% and a laparotomy was repeated. During the most recent examinations 86.5% of those patients checked had (virtually) no complaints--91.9% based upon the Visick classification. A subtotal intestinal obstruction occurred during the period of the study in 8.1% of cases, but could be conservatively treated. Up until the most recent examination there were still no instances of a late recurrence. Most intestinal obstruction recurrences are due to errors specific to the technique and are early recurrences. On the basis of our results, we are of the opinion that plication in the presence of existing peritonitis, as well as partial plication, is acceptable.
Asunto(s)
Obstrucción Intestinal/cirugía , Mesenterio/cirugía , Complicaciones Posoperatorias/cirugía , Adulto , Anciano , Femenino , Estudios de Seguimiento , Humanos , Obstrucción Intestinal/mortalidad , Masculino , Persona de Mediana Edad , Peritonitis/mortalidad , Peritonitis/cirugía , Complicaciones Posoperatorias/mortalidad , Recurrencia , Reoperación , Tasa de Supervivencia , Técnicas de Sutura , Adherencias Tisulares/cirugíaRESUMEN
Szilagyi's statement: 'The management of cases with infected arterial implants proves to be a task of grave and sometimes insurmountable difficulty' has kept its validity until today. In spite of restrictive patient selection, perfect surgical skill and perioperative antibiotic prophylaxis, infection of vascular grafts still do occur. Diagnosis has to be established without delay, and treatment of such often fatal infections is an aggressive surgical one.
Asunto(s)
Prótesis Vascular , Oclusión de Injerto Vascular/cirugía , Infección de la Herida Quirúrgica/cirugía , Humanos , ReoperaciónAsunto(s)
Meningocele/cirugía , Parálisis/etiología , Humanos , Masculino , Meningocele/complicaciones , Meningocele/diagnóstico , Persona de Mediana Edad , Mielografía , Neurofibromatosis 1/complicaciones , Complicaciones Posoperatorias , Radiografía Torácica , Tórax , Tomografía , Vejiga Urinaria Neurogénica/etiologíaAsunto(s)
Adenocarcinoma/cirugía , Carcinoma de Células Escamosas/cirugía , Trastornos de Deglución/cirugía , Neoplasias Esofágicas/cirugía , Intubación Gastrointestinal , Adenocarcinoma/mortalidad , Carcinoma de Células Escamosas/mortalidad , Neoplasias Esofágicas/mortalidad , Femenino , Estudios de Seguimiento , Humanos , Intubación Gastrointestinal/instrumentación , Tiempo de Internación , Masculino , Métodos , Persona de Mediana Edad , Cuidados Paliativos , Complicaciones Posoperatorias , Estudios Retrospectivos , Factores de TiempoAsunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Vacuna BCG/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias de la Mama/patología , Clorambucilo/administración & dosificación , Terapia Combinada , Relación Dosis-Respuesta a Droga , Femenino , Fluorouracilo/administración & dosificación , Humanos , Metástasis Linfática , Mastectomía , Metotrexato/administración & dosificación , Estadificación de Neoplasias , PronósticoRESUMEN
Extra-adrenal paraganglioma (chemodectoma) is a rare tumor; the tumor of the carotid body is the most frequently observed chemodectoma. Histochemical analysis of the glomus cell shows catecholamine in all cases, but functional activity of those tumors is an exception. The diagnosis of carotid body tumor can be confirmed by carotid arteriography. Surgery is the treatment of choice. Malignant degeneration of chemodectoma has been observed in a few cases.
Asunto(s)
Tumor del Cuerpo Carotídeo/diagnóstico , Paraganglioma/diagnóstico , Arterias Carótidas/diagnóstico por imagen , Tumor del Cuerpo Carotídeo/diagnóstico por imagen , Tumor del Cuerpo Carotídeo/patología , Diagnóstico Diferencial , Femenino , Humanos , Persona de Mediana Edad , Paraganglioma/diagnóstico por imagen , Paraganglioma/patología , RadiografíaRESUMEN
The case of a 31 year old male mongoloid patient is reported, where a congenital duodenal membrane, asymptomatic in childhood, had led to hiatal hernia, stricture of the oesophagus, and finally to carcinoma of the stricture (Fig. 1). Observation time until death was 26 months. In a first operation, the membrane was resected (Fig. 2) and Nissen's fundoplication performed. 31/2 months after that stricture, carcinoma was diagnosed. In the second operation, carcinoma was resected and continuity reestablished by oesophagogastrostomy. The patient died 8 months after the second intervention.
Asunto(s)
Síndrome de Down/complicaciones , Duodeno/anomalías , Neoplasias Esofágicas/etiología , Estenosis Esofágica/etiología , Hernia Diafragmática/etiología , Hernia Hiatal/etiología , Adulto , Neoplasias Esofágicas/cirugía , Estudios de Seguimiento , Hernia Hiatal/cirugía , Humanos , MasculinoRESUMEN
A series of 23 venous thrombectomies of the lower limb is presented. In 19 instances indirect thrombectomy of the iliacofemoral segment was performed. 1 direct thrombectomy of the v. cava inferior led to full lumen restoration. Direct thrombectomy of the popliteal vein was attempted in 3 cases, resulting in phlebographic and clinical normalization in 2 instances. In no instance did pulmonary embolism occur during or after venous thrombectomy.
Asunto(s)
Vena Femoral/cirugía , Vena Ilíaca/cirugía , Vena Poplítea/cirugía , Tromboflebitis/cirugía , Vena Cava Inferior/cirugía , Adulto , Femenino , Vena Femoral/diagnóstico por imagen , Humanos , Vena Ilíaca/diagnóstico por imagen , Vena Poplítea/diagnóstico por imagen , Radiografía , Tromboflebitis/diagnóstico por imagen , Vena Cava Inferior/diagnóstico por imagenRESUMEN
Fractures complicated by vascular trauma are rare but very complicated injuries. Clinical diagnosis is confirmed by Doppler sonography and/or arteriography. Time effectiveness in investigation and therapy is most important, cooperation between orthopedic and vascular surgeons is crucial. If indication is correct, arterial reconstruction has excellent results in these severe injuries.
Asunto(s)
Arteria Femoral/lesiones , Fracturas Abiertas/cirugía , Arterias Tibiales/lesiones , Arteria Femoral/diagnóstico por imagen , Arteria Femoral/cirugía , Fracturas Abiertas/diagnóstico por imagen , Humanos , Isquemia/diagnóstico por imagen , Isquemia/cirugía , Microcirugia , Grupo de Atención al Paciente , Arterias Tibiales/diagnóstico por imagen , Arterias Tibiales/cirugía , Ultrasonografía DopplerRESUMEN
In a series of 18 patients delayed embolectomy of the limb was performed 8-63 days after embolism had occurred. Three patients died (2 of them after amputation), and 7 limbs were amputated after surgery. In 10 instances blood flow was fully restored by the operation. Analysis of the 18 cases leads to the conclusion that the success of delayed embolectomy where neuromuscular function is intact depends primarily on surgical technique. Direct embolectomy by local or regional exposure of the obstructed arterial level is shown to produce better results than conventional (distant) balloon catheter embolectomy by proximal incision. This is thought to be due to increased mural adherence of the embolus, with secondary thrombus formation after a delay of 8 days or more. A plea is therefore made for a more aggressive surgical attitude to delayed arterial embolization. Provided that preoperative arteriography has localized the obstructive level and that the patient's general condition allows major vascular surgery, direct removal of the embolus and secondary thrombi by open exposure of the obstructed artery is recommended.