RESUMEN
Pediatric Budd-Chiari syndrome (BCS) is a rare cause of portal hypertension and liver disease in Europe and North America. In order to understand the long-term effect of radiological intervention on BCS we performed a single center retrospective review. Fourteen cases were identified; 6 of 14 (43%) had a congenital thrombophilia with many having multiple prothrombotic mutations. Two were managed with medical anticoagulation alone and two required super-urgent transplant for acute liver failure. The remaining 10 of 14 (71%) underwent radiological intervention: 1 of 14 thrombolysis, 5 of 14 angioplasty, and 4 of 14 transjugular intrahepatic portosystemic shunt (TIPS). Six of 14 (43%) patients required repeat radiological intervention (1 angioplasty, 5 TIPS) but none required surgical shunts or liver transplantation for chronic liver disease. The time between diagnosis and treatment did not predict the need for repeat radiological intervention. These data show that radiological intervention can be highly effective, and reduces the need for surgery, though it requires specialist multidisciplinary teams for monitoring.
Asunto(s)
Síndrome de Budd-Chiari , Derivación Portosistémica Intrahepática Transyugular , Humanos , Niño , Síndrome de Budd-Chiari/diagnóstico , Síndrome de Budd-Chiari/terapia , Estudios Retrospectivos , Angioplastia , Reino Unido , Resultado del TratamientoRESUMEN
Despite undeniable improvement in the management of rheumatoid arthritis (RA), the discovery of more effective, less toxic and, ideally, less immune suppressive drugs are much needed. In the current study, we set to explore the potential anti-rheumatic activity of the non-toxic, tellurium-based immunomodulator, AS101 in an experimental animal model of RA. The effect of AS101 was assessed on adjuvant-induced arthritis (AIA) rats. Clinical signs of arthritis were assessed. Histopathological examination was used to assess inflammation, synovial changes and tissue lesions. Very late antigen-4 (VLA-4)+ cellular infiltration was detected using immunohistochemical staining. Enzyme-linked immunosorbent assay (ELISA) was used to measure circulating anti-cyclic citrullinated-peptide autoantibody (ACPA) and real-time polymerase chain reaction (PCR) was used to measure the in-vitro effect of AS101 on interleukin (IL)-6 and IL-1ß expression in activated primary human fibroblasts. Prophylactic treatment with intraperitoneal AS101 reduced clinical arthritis scores in AIA rats (P < 0·01). AS101 abrogated the migration of active chronic inflammatory immune cells, particularly VLA-4+ cells, into joint cartilage and synovium, reduced the extent of joint damage and preserved joint architecture. Compared to phosphate-buffered saline (PBS)-treated AIA rats, histopathological inflammatory scores were significantly reduced (P < 0·05). Furthermore, AS101 resulted in a marked reduction of circulating ACPA in comparison to PBS-treated rats (P < 0·05). Importantly, AS101 significantly reduced mRNA levels of proinflammatory mediators such as IL-6 (P < 0·05) and IL-1ß (P < 0·01) in activated primary human fibroblasts. Taken together, we report the first demonstration of the anti-rheumatic/inflammatory activity of AS101 in experimental RA model, thereby supporting an alternative early therapeutic intervention and identifying a promising agent for therapeutic intervention.
Asunto(s)
Artritis Experimental/inmunología , Artritis Reumatoide/inmunología , Etilenos/inmunología , Telurio/inmunología , Adyuvantes Inmunológicos/farmacología , Animales , Artritis Experimental/metabolismo , Artritis Experimental/prevención & control , Artritis Reumatoide/metabolismo , Artritis Reumatoide/prevención & control , Células Cultivadas , Etilenos/farmacología , Femenino , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Expresión Génica/efectos de los fármacos , Humanos , Factores Inmunológicos/inmunología , Factores Inmunológicos/farmacología , Integrina alfa4beta1/inmunología , Integrina alfa4beta1/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Ratas Endogámicas Lew , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Telurio/farmacologíaRESUMEN
Ferritin, which was only discovered in the last century, has stirred a formidable debate. Ferritin has long been appreciated as a non-specific acute-phase reactant. Several years ago, we hypothesized the contributory role of ferritin as a pathogenic molecule rather than being a product of inflammation. The latest emerging evidence provides support to this notion. Such revelation provides a step forward towards the understanding of disease conditions associated with hyperferritinaemia, and hence provide new targets for treatment modalities.
Asunto(s)
Proteínas de Fase Aguda/metabolismo , Ferritinas/metabolismo , Inflamación/inmunología , Trastornos del Metabolismo del Hierro/inmunología , Macrófagos/inmunología , Animales , Humanos , Inmunomodulación , Activación de Macrófagos , Terapia Molecular DirigidaRESUMEN
WHAT IS KNOWN AND OBJECTIVES: Rituximab is a chimeric monoclonal anti-CD20 antibody approved for the treatment of some lymphoid malignancies as well as for autoimmune diseases including rheumatoid arthritis (RA), idiopathic thrombocytopenic purpura (ITP) and vasculitis. Generally, rituximab is well tolerated; nevertheless, some patients develop adverse effects including infusion reactions. Albeit rare, these reactions may in some cases be life-threatening conditions. Rituximab cardiovascular side effects include more common effects such as hypertension, oedema and rare cases of arrhythmias and myocardial infarction. CASE SUMMARY: In this article, we report a case of a 58-year-old man with a history of overlap syndrome including RA and limited scleroderma who was treated with rituximab and developed a dramatic ST-elevation myocardial infarction (STEMI) during the drug administration. WHAT IS NEW AND CONCLUSION: This report underlines previous published reports emphasizing the awareness of such an association. This communication also warrants the importance of screening for ischaemic heart disease in selected cases of patients treated with rituximab.
Asunto(s)
Antirreumáticos/efectos adversos , Rituximab/efectos adversos , Infarto del Miocardio con Elevación del ST/inducido químicamente , Antirreumáticos/administración & dosificación , Artritis Reumatoide/tratamiento farmacológico , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Rituximab/administración & dosificación , Esclerodermia Limitada/tratamiento farmacológico , Enfermedades Indiferenciadas del Tejido Conectivo/tratamiento farmacológicoRESUMEN
Late-onset LAL deficiency, previously referred to as cholesteryl ester storage disorder, is a rare lysosomal storage disorder characterized by accumulation of cholesteryl esters. It has a heterogeneous clinical phenotype including abdominal pain, poor growth, hyperlipidemia with vascular complications and hepatosplenomegaly. End-stage liver disease may occur, but there are few reports of successful LT. There are also concerns that systemic manifestations of the disease might persist post-LT. We report a case with excellent outcome eight yr following LT. The subject was noted to have asymptomatic hepatosplenomegaly during an intercurrent illness, and LAL deficiency was confirmed with compound heterozygosity in the LIPA. Despite dietary fat restriction, he developed signs of progressive liver disease and subsequently developed hepatopulmonary syndrome. He underwent cadaveric LT at the age of nine and a half yr and recovered with prompt resolution of hepatopulmonary syndrome. Eight yr post-transplant he has normal growth, normal lipid profile, and liver and renal function tests. Liver histology showed no evidence of disease recurrence at this stage. LT in this subject resulted in an excellent functional correction of late-onset LAL deficiency.
Asunto(s)
Trasplante de Hígado , Enfermedad de Wolman/cirugía , Niño , Humanos , Masculino , Enfermedad de WolmanRESUMEN
Propionic acidemia (PA) is a severe metabolic disorder with cardiac and neurologic complications and a poor quality of life. Liver transplantation (LT) was thus proposed in PA to increase enzyme activity. We studied retrospectively LT in PA in two European centers. Twelve patients underwent 17 LTs between 1991 and 2013. They developed severe, unusual and unexpected complications, with high mortality (58%). When present, the cardiomyopathy resolved and no acute metabolic decompensation occurred allowing dietary relaxation. Renal failure was present in half of the patients before LT and worsened in all of them. We suggest that cardiac and renal functions should be assessed before LT and monitored closely afterward. A renal sparing immunosuppression should be used. We speculate that some complications may be related to accumulated toxicity of the disease and that earlier LT could prevent some of these consequences. As kidney transplantation has been performed successfully in methylmalonic acidemia, a metabolic disease in the same biochemical pathway, the choice of the organ to transplant could be further discussed.
Asunto(s)
Trasplante de Hígado/efectos adversos , Acidemia Propiónica/cirugía , Niño , Femenino , Humanos , Inmunosupresores/administración & dosificación , Masculino , Acidemia Propiónica/fisiopatologíaRESUMEN
Multivariate analysis of thin-layer chromatography (TLC) images was modeled to predict antioxidant activity of Pereskia bleo leaves and to identify the contributing compounds of the activity. TLC was developed in optimized mobile phase using the 'PRISMA' optimization method and the image was then converted to wavelet signals and imported for multivariate analysis. An orthogonal partial least square (OPLS) model was developed consisting of a wavelet-converted TLC image and 2,2-diphynyl-picrylhydrazyl free radical scavenging activity of 24 different preparations of P. bleo as the x- and y-variables, respectively. The quality of the constructed OPLS model (1 + 1 + 0) with one predictive and one orthogonal component was evaluated by internal and external validity tests. The validated model was then used to identify the contributing spot from the TLC plate that was then analyzed by GC-MS after trimethylsilyl derivatization. Glycerol and amine compounds were mainly found to contribute to the antioxidant activity of the sample. An alternative method to predict the antioxidant activity of a new sample of P. bleo leaves has been developed.
Asunto(s)
Antioxidantes , Cactaceae/química , Cromatografía en Capa Delgada/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Antioxidantes/análisis , Antioxidantes/química , Antioxidantes/metabolismo , Análisis de los Mínimos Cuadrados , Análisis Multivariante , Extractos Vegetales/química , Hojas de la Planta/químicaRESUMEN
To compare the incidence of acute histologically proven rejection in children who have had a liver transplant for hepatoblastoma with a control group of children transplanted for biliary atresia (EHBA). A retrospective case notes based study was performed. Twenty patients were identified with hepatoblastoma who were transplanted at a single unit between 1991 and 2008. These were matched as closely as possible for age, gender, year of transplant and type of immunosuppression used to the control group transplanted for biliary atresia (n = 60). There was a significant decrease in rate of acute rejection as assessed by the rejection activity index (RAI) in the hepatoblastoma group (75% vs. 50%, respectively, p < 0.04). Chronic rejection was rare in both groups, but twice as common in the biliary atresia group. Equal levels of immunosuppression were achieved in both groups. Renal function was noted to be reduced one yr post-transplant in both groups, as previously reported. A modified immunosuppression regimen could be considered in children with hepatoblastoma undergoing liver transplantation.
Asunto(s)
Rechazo de Injerto/epidemiología , Hepatoblastoma/terapia , Neoplasias Hepáticas/terapia , Trasplante de Hígado , Atresia Biliar/terapia , Niño , Preescolar , Femenino , Humanos , Terapia de Inmunosupresión , Inmunosupresores/uso terapéutico , Masculino , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
AIMS: To report the results and successes of intestinal transplantation (ITx) in the most active European centres, to emphasize that, although it is a difficult procedure, it should remain a therapeutic option for children with total, definitive and complicated intestinal failure when intestinal rehabilitation fails. METHODS: We retrospectively collected data about all patients less than 18 receiving an ITx from 2010 to 2022 in 8 centres, and outcomes in July 2022. RESULTS: ITx was performed in 155 patients, median age 6.9 years, in 45% for short bowel syndromes, 22% congenital enteropathies, 25% motility disorders, and 15% re-transplantations. Indications were multiple in most patients, intestinal failure-associated liver disease in half. The graft was in 70% liver-containing. At last follow up 64% were alive, weaned from parenteral nutrition, for 7.9 years; 27% had died and the graft was removed in 8%, mostly early after ITx. DISCUSSION: ITx, despite its difficulties, can give a future to children with complicated intestinal failure. It should be considered among the therapeutic options offered to patients with a predicted survival rate lower than that after ITx. Patients should be early discussed within multidisciplinary teams in ITx centres, to avoid severe complications impacting the results of ITx, or even to avoid ITx.
Asunto(s)
Intestinos , Humanos , Estudios Retrospectivos , Niño , Masculino , Femenino , Intestinos/trasplante , Preescolar , Lactante , Resultado del Tratamiento , Adolescente , Insuficiencia Intestinal , Síndrome del Intestino Corto/cirugía , Enfermedades Intestinales/cirugía , Europa (Continente) , Nutrición ParenteralRESUMEN
Liver and small bowel transplant is an established treatment for infants with IFALD. Despite organ reduction techniques, mortality on the waiting list remains high due to shortage of size-matched pediatric donors. Small abdominal cavity volume due to previous intestinal resection poses a significant challenge to achieve abdominal closure post-transplant. Seven children underwent tissue expansion of abdominal skin prior to multiorgan transplant. In total, 17 tissue expanders were placed subcutaneously in seven children. All seven subjects underwent re-exploration to deal with complications: hematoma, extrusion, infection, or port related. Three expanders had to be removed. Four children went on to have successful combined liver and small bowel transplant. Two children died on the waiting list of causes not related to the expander and one child died from sepsis attributed to an infected expander. Tissue expansion can generate skin to facilitate closure of abdomen post-transplant, thus allowing infants with small abdominal volumes to be considered for transplant surgery. Tissue expansion in children with end-stage liver disease and portal hypertension is associated with a very high complication rate and needs to be closely monitored during the expansion process.
Asunto(s)
Intestino Delgado/cirugía , Intestinos/trasplante , Trasplante de Hígado , Complicaciones Posoperatorias/etiología , Expansión de Tejido/métodos , Cavidad Abdominal/cirugía , Estudios de Cohortes , Colágeno/química , Enfermedad Hepática en Estado Terminal/complicaciones , Enfermedad Hepática en Estado Terminal/terapia , Enterocolitis Necrotizante/cirugía , Femenino , Gastrosquisis/cirugía , Hematoma/etiología , Humanos , Lactante , Infecciones/etiología , Atresia Intestinal/cirugía , Masculino , Complicaciones Posoperatorias/diagnóstico , Sepsis/etiología , Sepsis/mortalidad , Síndrome del Intestino Corto/cirugíaRESUMEN
BACKGROUND AND AIM: A select group of children with short bowel syndrome (SBS) and intestinal failure-associated liver disease (IFALD) fulfill the criteria for isolated liver transplantation (iLTx). Long-term results in this group of patients have not been reported. METHODS: A retrospective study of the medical records of 8 survivors of 14 children who underwent iLTx for SBS and IFALD from 1998 to 2005, managed by a multidisciplinary intestinal rehabilitation team at our institution. RESULTS: Median follow-up is 107.5 months (range 89-153 months). Five of 8 children were weaned from parenteral nutrition (PN) to enteral nutrition (EN) in a median of 10 months after iLTx (range 3-32 months). Three of 5 children were subsequently weaned from EN to full oral feeding in 13, 24, and 53 months after stopping PN, whereas the remaining 2 are still receiving EN 118 and 74 months after stopping PN. These 5 children maintain their weight median z scores with a median increase of 1.59 (range 1.24-1.79) compared with the pretransplant z score, whereas the height z scores show fluctuations through the years with a median change of 0.12 (range -0.29 to 0.36). The other 3 of 8 children developed progressive intestinal failure; 2 underwent isolated small bowel transplantation 112 and 84 months after iLTx and the third is receiving PN. CONCLUSIONS: Children with SBS and IFALD who have the potential for adaptation in the residual bowel can undergo iLTx, but it is a treatment option to be exercised with extreme caution. These children need close follow-up with an experienced multidisciplinary team to monitor nutritional outcomes and may need consideration for transplant or nontransplant surgery in the long term.
Asunto(s)
Enfermedades Intestinales/terapia , Intestinos/patología , Fallo Hepático/terapia , Trasplante de Hígado , Síndrome del Intestino Corto/terapia , Adolescente , Niño , Procedimientos Quirúrgicos del Sistema Digestivo/métodos , Nutrición Enteral , Estudios de Seguimiento , Humanos , Enfermedades Intestinales/complicaciones , Enfermedades Intestinales/patología , Fallo Hepático/complicaciones , Fallo Hepático/patología , Nutrición Parenteral , Estudios Retrospectivos , Síndrome del Intestino Corto/complicaciones , Síndrome del Intestino Corto/patología , Resultado del TratamientoRESUMEN
Following paediatric SBMT, size discrepancy between the recipient's abdomen and the graft may lead to ACS, graft dysfunction, and death. We report our experience with SAC in these patients. Between 04/1993 and 03/2009, 57 children underwent 62 SBMTs. When abdominal wall tension seemed excessive for safe PAC, SAC was performed, using a Silastic® sheet and a vacuum occlusive dressing. Transplantations with SAC (23 combined liver and small bowel [CLB]) were compared with those with PAC [14 ISB and 25 CLB]. Indications for transplantation, preoperative status (after stratification for ISB/CLB transplants), age at transplantation, donor-to-recipient weight ratio, reduction in bowel and/or liver, and incidence of wound complications were not different in both groups. Post-operative intubation, stay in intensive care unit, and hospital stay were prolonged after SAC. Two deaths were related to ACS after PAC, none after SAC. Since 2000, one-yr patient survival is 73% after ISB transplantation and 57% vs. 75% after CLB transplantation with PAC vs. SAC, respectively (NS). SAC safely reduces severe ACS after paediatric SBMT and can be combined with graft reduction for transplantation of small recipients.
Asunto(s)
Pared Abdominal/cirugía , Intestino Delgado/trasplante , Intestinos/trasplante , Hipertensión Intraabdominal/prevención & control , Niño , Preescolar , Procedimientos Quirúrgicos del Sistema Digestivo/métodos , Supervivencia de Injerto , Humanos , Enfermedades Intestinales/terapia , Intestino Delgado/patología , Intestinos/patología , Hígado/patología , Trasplante de Hígado/métodos , Complicaciones Posoperatorias , Factores de Tiempo , Resultado del TratamientoRESUMEN
A male infant was diagnosed with atypical hemolytic uremic syndrome (aHUS) at the age of 5.5 months. Sequencing of the gene (CFH) encoding complement factor H revealed a heterozygous mutation (c.3644G>A, p.Arg1215Gln). Despite maintenance plasmapheresis he developed recurrent episodes of aHUS and vascular access complications while maintaining stable renal function. At the age of 5 years he received an isolated split liver graft following a previously established protocol using pretransplant plasma exchange (PE) and intratransplant plasma infusion. Graft function, renal function and disease remission are preserved 2 years after transplantation. Preemptive liver transplantation prior to the development of end stage renal disease is a valuable option in the management of aHUS associated with CFH mutations.
Asunto(s)
Factor H de Complemento/genética , Síndrome Hemolítico-Urémico/genética , Síndrome Hemolítico-Urémico/cirugía , Trasplante de Hígado , Mutación , Infecciones por Caliciviridae/etiología , Gastroenteritis/virología , Síndrome Hemolítico-Urémico/fisiopatología , Herpesvirus Humano 4 , Heterocigoto , Humanos , Recién Nacido , Riñón/fisiopatología , Trasplante de Hígado/efectos adversos , Masculino , Norovirus , Complicaciones Posoperatorias , Medición de Riesgo , Prevención Secundaria , Viremia/etiologíaRESUMEN
This study evaluated the results of a management protocol combining a number of investigations and interventions, previously proven beneficial in randomized controlled trials in IVF/intracytoplasmic sperm injection (ICSI) patients with apparently unexplained recurrent implantation failure (defined as two or more previous failed cycles, during which at least six good-quality embryos were transferred). It was a prospective cohort study and included 273 couples with previous recurrent implantation failure. Each patient (all under 40) underwent a pre-treatment work-up, consisting of pelvic ultrasound scan for hydrosalpinx, hysteroscopy and screening for acquired and congenital thrombophilia. Detected abnormalities were dealt with accordingly: proximal occlusion for hydrosalpinx, hysteroscopic management for intrauterine pathology and thromboprophylaxis with daily low-molecular weight heparin from the day of embryo transfer for thrombophilia. The patients then underwent IVF/ICSI with laser-assisted hatching. 112 patients (41%; group 1) had abnormalities detected (17 hydrosalpinx, 11 intrauterine pathology, 63 congenital thrombophilia, 21 acquired thrombophilia) and the remaining 161 (59%; group 2) had normal work-up. The pregnancy rates per cycle started for all patients, group 1 and group 2 were 47%, 55% and 41%, respectively. This suggests that using the described management protocol in couples with previous recurrent implantation failure leads to a favourable chance of success.
Asunto(s)
Infertilidad/terapia , Técnicas Reproductivas Asistidas , Adulto , Protocolos Clínicos , Implantación del Embrión , Transferencia de Embrión , Medicina Basada en la Evidencia , Trompas Uterinas/patología , Femenino , Fertilización In Vitro , Humanos , Histeroscopía , Infertilidad/etiología , Cariotipificación , Masculino , Embarazo , Recurrencia , Inyecciones de Esperma Intracitoplasmáticas , Trombofilia/complicaciones , Trombofilia/diagnóstico , Insuficiencia del TratamientoRESUMEN
Selected livers from controlled NHBD are accepted for OLT in adults. Recent evidence has shown good medium-term outcome. The purpose of this study was to report our experience of pediatric OLT with whole and partial grafts from NHBD, analyzing complications and outcome. Retrospective review of all the recipients who underwent primary OLT between December 2005 and December 2008, using livers from NHBD. Four children (one male child) mean age was 9.5 yr (0.2-17), mean weight was 26 kg (range 2.6-48), underwent OLT using NHBD. Mean donor age was 14.2 yr, and mean WIT (systolic BP<50 mmHg to cold perfusion) 12.2 min (range 10-15). Two children received reduced grafts and two full grafts. Mean cold ischemia time was 7.18 h (range 6-8). Liver function tests one wk and nine months post-OLT confirmed a good graft function. One child was treated for two episodes of acute rejection. Post-transplant complications included two cases of mild ischemic cholangiopathy treated conservatively. Graft and patient survival was 100% with a mean follow-up of 19 months (range 8.1-43.4). Short- to medium-term follow-up suggests that liver grafts from young NHBD with short warm and cold ischemia times can be safely utilized in pediatric transplantation.
Asunto(s)
Paro Cardíaco , Trasplante de Hígado/fisiología , Donantes de Tejidos/estadística & datos numéricos , Adolescente , Niño , Preescolar , Isquemia Fría , Humanos , Lactante , Trasplante de Hígado/mortalidad , Tamaño de los Órganos , Estudios Retrospectivos , Análisis de Supervivencia , Listas de Espera , Isquemia TibiaRESUMEN
[This corrects the article DOI: 10.1016/j.jpra.2018.03.003.].
RESUMEN
An 11-year-old boy with irreversible intestinal failure secondary to chronic intestinal pseudo-obstruction (CIPO) and intestinal failure-associated liver disease (IFALD) underwent a combined en bloc reduced liver and small bowel transplantation. He was discharged home after 9 weeks on full oral intake without requiring intravenous nutritional or fluid supplementation. The first episode of mild acute rejection, which occurred 18 months after transplantation, was successfully treated with steroids. An episode of rotavirus gastroenteritis led to severe exfoliative rejection of the bowel graft, which was resistant to steroid and Infliximab treatment but responded to OKT3. There was associated Epstein-Barr virus viremia with no evidence of posttransplant lymphoproliferative disease. Another episode of moderate to severe acute liver rejection occurred 5 months later. At the same time, multiple biliary strictures were diagnosed and treated. Persistent clinical symptoms of abdominal pain and increased stomal output as well as atrophy of the ileal mucosa on several biopsies, suggested the possibility of chronic rejection (CR). A second combined whole liver and small bowel transplant was performed. The diagnosis of CR was confirmed on histology of the explanted graft. The postoperative course was severely complicated and 71 days after the retransplantation, the boy died because of respiratory failure and multiorgan failure. In summary, intestinal transplantation can be successfully performed in children with CIPO, giving them the opportunity to be free from total parenteral nutrition. As survival following intestinal transplantation continues to improve, the problem of CR has become increasingly important and the only treatment available is retransplantation, which is associated with poor outcomes.
Asunto(s)
Rechazo de Injerto/tratamiento farmacológico , Seudoobstrucción Intestinal/cirugía , Intestino Delgado/trasplante , Trasplante de Hígado , Corticoesteroides/uso terapéutico , Niño , Enfermedad Crónica , Colon/trasplante , Resultado Fatal , Humanos , Inmunosupresores/uso terapéutico , Trasplante de Hígado/efectos adversos , Masculino , Insuficiencia Multiorgánica , Trasplante de Páncreas/efectos adversos , ReoperaciónRESUMEN
This is a report describing the case of a 66-year-old male with development of halo naevi. A biopsy of one of these naevi revealed a malignant melanoma with extensive regression. The purpose of this report is to identify that development of halo naevi outside of childhood or adolescence should raise suspicion and may require biopsy.
RESUMEN
Micropitting is a form of surface fatigue damage that happens at the surface roughness scale in lubricated contacts in commonly used machine elements, such as gears and bearings. It occurs where the specific film thickness (ratio of smooth surface film thickness to composite surface roughness) is sufficiently low for the contacts to operate in the mixed lubrication regime, where the load is in part carried by direct asperity contacts. Micropitting is currently seen as a greater issue for gear designers than is regular pitting fatigue failure as the latter can be avoided by control of steel cleanliness. This paper describes the results of both theoretical and experimental studies of the onset of micropitting in test disks operated in the mixed lubrication regime. A series of twin disk mixed-lubrication experiments were performed in order to examine the evolution of micropitting damage during repeated cyclic loading of surface roughness asperities as they pass through the contact. Representative measurements of the surfaces used in the experimental work were then evaluated using a numerical model which combines a transient line contact micro-elastohydrodynamic lubrication (micro-EHL) simulation with a calculation of elastic sub-surface stresses. This model generated time-history of stresses within a block of material as it passes through the contact, based on the instantaneous surface contact pressure and traction at each point in the computing mesh at each timestep. This stress time-history was then used within a shear-strain-based fatigue model to calculate the cumulative damage experienced by the surface due to the loading sequence experienced during the experiments. The proposed micro-EHL model results and the experimental study were shown to agree well in terms of predicting the number of loading cycles that are required for the initial micropitting to occur.
RESUMEN
In this unusual case, accumulation of silver nitrate used to treat over-granulation in a finger injury led to a near-misdiagnosis of a bony tumour on X-ray. This underlines the need to support X-ray results with a full clinical assessment.