Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 68
Filtrar
1.
Gen Comp Endocrinol ; 290: 113393, 2020 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-31982398

RESUMEN

In the lacertid Podarcis siculus the reproductive cycle is typically biphasic, with alternate recrudescence (Spring and Fall) and resting (Summer and Winter) phases. This study aimed to shed some light on the role exerted by progesterone during the two recrudescence periods; to this purpose, exogenous progesterone was administered intraperitoneally and the effects on oogonial proliferation, oocyte recruitment, and follicle cells apoptosis were determined. The presence and distribution of progesterone receptors was also investigated by immunohistochemistry and western blotting. Results indicate that progesterone would play different roles and follow different route of action in the two recrudescence periods thus confirming the complexity of the mechanisms controlling oogenesis in this species of vertebrate.


Asunto(s)
Lagartos , Ovario/fisiopatología , Progesterona/metabolismo , Animales , Femenino , Recurrencia , Estaciones del Año
2.
Mar Environ Res ; 193: 106293, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38103302

RESUMEN

Here we provide evidence, along an 8-year period time-series based on multifaceted data from a Mediterranean marine protected area (MPA), whether protection can tackle invasive and range expanding herbivore fishes, and their effects on the algal resource availability, taking into account the population trends of predatory fishes, fisheries catches of herbivore fishes and sea surface temperature (SST) through time. Our findings pointed out that an ineffective in restoring top-down control process MPA may facilitate, rather than alleviate, the sudden and enduring population burst of invasive and range-expanding herbivorous fishes at tipping points of abrupt change. This subsequently results in the deterioration of rocky reef habitats and the depletion of algal resources, with the tipping points of abrupt change for algal and herbivore fish species not overlapping chronologically. As sea temperature increases, ineffective or recently established MPAs may inadvertently facilitate the proliferation of invasive and range-expanding species, posing a significant challenge to management effectiveness and conservation objectives.


Asunto(s)
Ecosistema , Herbivoria , Animales , Peces , Explotaciones Pesqueras , Temperatura , Conservación de los Recursos Naturales
3.
Commun Agric Appl Biol Sci ; 78(2): 55-63, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-25145225

RESUMEN

Chemical and eating quality of citrus fruit changes slowly after harvest, and quality alteration is mainly due to shrinkage, loss of firmness, excessive weight loss and decay rather than a reduction of nutritional value and taste features. Film wrapping may be a suitable means to reduce transpiration and preserve market quality provided film permeability to gases does not lead to: 1) a reduction of in-package O2 partial pressure at a point that would induce anaerobic respiration; 2) an increase of CO2 concentration to toxic levels. This experiment was carried out to study quality changes of 'Sanguinello' oranges treated or not treated with 500 mg/L imazalil (IMZ) and wrapped with continuous, macro- or micro-perforated polyolefinic films. Wrapped and no-wrapped fruit were stored at 20 degrees C and 60% RH for 20 or 30 days. In-package gas composition of the macro-perforated film showed no significant difference compared to air composition, while in-package partial pressure of CO2 and O2 ranged between 4 (continuous film) and 9.8 kPa (micro-perforated films), and 14.8 (continuous film) and 5 kPa (micro-perforated films), respectively. After 30 days of storage weight loss in fruit wrapped with the macro-perforated film was (4.3%) slightly lowerthan un-packed fruit (5%), while in all other packages weight loss never exceeded 0.7%.Quality changes were quite stable over storage in all treatments, although slight but significantly lower levels of total soluble solids and ascorbic acid were detected in micro-perforated films with the lowest degree of perforation. However, the sensory analysis denoted a remarkable decrease of firmness in un-wrapped or wrapped fruit with macro-perforated film, while a moderate build-up of off-flavour, which reduced the eating quality, developed in micro-perforated films. Decay ranged between 6 and 12% in not treated fruit, with the lowest incidence detected in un-wrapped fruit, whereas differences among the different films were not significant. No decay was detected in fruit treated with IMZ. 'Sanguinello' oranges can be stored under retail conditions for a month by the only means of film wrapping without important changes in chemical, eating and marketing quality provided fruit are treated with an effective fungicide to prevent decay and that in-package gas composition is not markedly changed with respect to air.


Asunto(s)
Citrus sinensis/química , Embalaje de Alimentos/instrumentación , Embalaje de Alimentos/métodos , Frutas/química , Plásticos/química , Embalaje de Alimentos/economía , Conservación de Alimentos , Almacenamiento de Alimentos , Frutas/economía , Humanos , Permeabilidad , Control de Calidad , Gusto
4.
Curr Nutr Rep ; 12(3): 527-544, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37213054

RESUMEN

PURPOSE OF REVIEW: Polycystic ovary syndrome (PCOS) is the most common endocrine and metabolic disorder in women of reproductive age worldwide. This disease causes menstrual, metabolic, and biochemical abnormalities such as hyperandrogenism, oligo-anovulatory menstrual cycles, polycystic ovary, hyperleptinemia, insulin resistance (IR), and cardiometabolic disorders, often associated with overweight or obesity and visceral adiposity. RECENT FINDINGS: The etiology and pathophysiology of PCOS are not yet fully understood, but insulin seems to play a key role in this disease. PCOS shares an inflammatory state with other chronic diseases such as obesity, type II diabetes, and cardiovascular diseases; however, recent studies have shown that a healthy nutritional approach can improve IR and metabolic and reproductive functions, representing a valid therapeutic strategy to ameliorate PCOS symptomatology. This review aimed to summarize and collect evidence about different nutritional approaches such as the Mediterranean diet (MedDiet) and the ketogenic diet (KD), as well as bariatric surgery and nutraceutical supplementation as probiotics, prebiotics, and synbiotics, among the others, used in patients with PCOS.


Asunto(s)
Diabetes Mellitus Tipo 2 , Hiperandrogenismo , Resistencia a la Insulina , Síndrome del Ovario Poliquístico , Humanos , Femenino , Síndrome del Ovario Poliquístico/complicaciones , Síndrome del Ovario Poliquístico/tratamiento farmacológico , Hiperandrogenismo/complicaciones , Obesidad/complicaciones
5.
Environ Int ; 161: 107143, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35176575

RESUMEN

With the advent of the SARS-CoV-2 pandemic, Wastewater-Based Epidemiology (WBE) has been applied to track community infection in cities worldwide and has proven succesful as an early warning system for identification of hotspots and changingprevalence of infections (both symptomatic and asymptomatic) at a city or sub-city level. Wastewater is only one of environmental compartments that requires consideration. In this manuscript, we have critically evaluated the knowledge-base and preparedness for building early warning systems in a rapidly urbanising world, with particular attention to Africa, which experiences rapid population growth and urbanisation. We have proposed a Digital Urban Environment Fingerprinting Platform (DUEF) - a new approach in hazard forecasting and early-warning systems for global health risks and an extension to the existing concept of smart cities. The urban environment (especially wastewater) contains a complex mixture of substances including toxic chemicals, infectious biological agents and human excretion products. DUEF assumes that these specific endo- and exogenous residues, anonymously pooled by communities' wastewater, are indicative of community-wide exposure and the resulting effects. DUEF postulates that the measurement of the substances continuously and anonymously pooled by the receiving environment (sewage, surface water, soils and air), can provide near real-time dynamic information about the quantity and type of physical, biological or chemical stressors to which the surveyed systems are exposed, and can create a risk profile on the potential effects of these exposures. Successful development and utilisation of a DUEF globally requires a tiered approach including: Stage I: network building, capacity building, stakeholder engagement as well as a conceptual model, followed by Stage II: DUEF development, Stage III: implementation, and Stage IV: management and utilization. We have identified four key pillars required for the establishment of a DUEF framework: (1) Environmental fingerprints, (2) Socioeconomic fingerprints, (3) Statistics and modelling and (4) Information systems. This manuscript critically evaluates the current knowledge base within each pillar and provides recommendations for further developments with an aim of laying grounds for successful development of global DUEF platforms.


Asunto(s)
COVID-19 , Monitoreo Epidemiológico Basado en Aguas Residuales , COVID-19/epidemiología , Salud Global , Humanos , Pandemias , SARS-CoV-2 , Aguas Residuales
6.
Environ Pollut ; 266(Pt 1): 115213, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32688110

RESUMEN

Abundance, composition, and distribution of macro-litter found on the seafloor of the Strait of Sicily between 10 and 800 m depth has been studied using data collected by bottom trawl surveys MEDITS from 2015 to 2019. Three waste categories based on the items use were considered: single-use, fishing-related and generic-use. Over 600 sampling sites, just 14% of these were litter-free. The five-years average density of seafloor litter was 79.6 items/km2 and ranged between 46.8 in 2019 and 118.1 items/km2 in 2015. The predominant waste type was plastic (58% of all items). Regardless of material type, single-use items were a dominant (60% of items) and widespread (79% of hauls) fraction of litter with a mean density of 48.4 items/km2. Fishing-related items accounted for 12% of total litter items. Percentage of dirty hauls and litter density increased with depth. Analysis of the relation density-depth indicates a progressive increase of litter density beyond depth values situated within the interval 234-477 m depending on the litter category. A significant decrease in litter density by categories was observed over the period. Patterns of spatial distribution at the higher depths (200-80 0m) resulted stable over the years. Density hotspots of fishing-related items were found where the fishing activity that uses fish aggregating devices (FADs) is practised and in the proximity of rocky banks. Single-use and generic-use objects densities were greater on the seafloor along main maritime routes than other areas. Comparisons between the percentage of hauls littered with anthropic waste from the mid-1990s against those in 2018-19 highlighted an increase of about 10.8% and 15.3% for single-use items and fishing-related items respectively, and a decrease of 18.6% for generic-use items. This study provides a snapshot of the current situation of littering in the central Mediterranean Sea and represents a solid baseline against which the effectiveness of current and future mitigation strategies of the litter impact on marine environment can be measured.


Asunto(s)
Monitoreo del Ambiente , Residuos/análisis , Animales , Mar Mediterráneo , Plásticos , Sicilia
8.
Am J Med ; 110(7): 528-35, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11343666

RESUMEN

PURPOSE: Echocardiography is advocated by some as a useful diagnostic test for patients with suspected pulmonary embolism (PE), but its diagnostic accuracy is unknown. The present study was undertaken to determine prospectively the sensitivity and specificity of transthoracic echocardiography in the diagnosis of PE. SUBJECTS AND METHODS: We examined 110 consecutive patients with suspected PE. The study protocol included assessment of clinical probability, echocardiography, and perfusion lung scanning. Pulmonary angiography was performed in all patients with abnormal scans. As echocardiographic criteria to diagnose acute PE, we used the presence of any two of the following: right ventricular (RV) hypokinesis, RV end-diastolic diameter >27 mm (without RV wall hypertrophy), or tricuspid regurgitation velocity >2.7 m/sec. Clinical estimates of PE served as pretest probabilities in calculating, after echocardiography, the posttest probabilities of PE. RESULTS: Pulmonary angiography confirmed PE in 43 (39%) of 110 patients. Echocardiographic diagnostic criteria for PE yielded a sensitivity of 56% and a specificity of 90%. For pretest probabilities of 10%, 50%, and 90%, the posttest probabilities of PE conditioned by a positive echocardiogram were 38%, 85%, and 98%, respectively. The posttest probabilities of PE conditioned by a negative echocardiogram were 5%, 33%, and 81%, respectively. CONCLUSIONS: In unselected patients with suspected PE, transthoracic echocardiography fails to identify some 50% of patients with angiographically proven PE. Although echocardiographic findings of RV strain, paired with a high clinical likelihood, support a diagnosis of PE, the transthoracic echocardiography has to have a better sensitivity to be used as a screening test to rule out PE.


Asunto(s)
Embolia Pulmonar/diagnóstico por imagen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Ecocardiografía Doppler , Femenino , Humanos , Masculino , Persona de Mediana Edad , Probabilidad , Estudios Prospectivos , Estándares de Referencia , Factores de Riesgo , Sensibilidad y Especificidad
9.
Res Microbiol ; 149(1): 15-25, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9766205

RESUMEN

We have investigated the role of H-NS, one of the major components of the bacterial nucleoid, in the expression of the virF gene present on the large virulence plasmid of Shigella and enteroinvasive Escherichia coli in response to different environmental conditions. VirF is an AraC-like protein which activates at least two promoters, virB and virG, both repressed by H-NS. Band shift experiments reveal that the affinity of H-NS for the virF and virB promoters is comparable, while the affinity for the virG promoter is higher. Polyacrylamide gel electrophoresis of three DNA fragments containing the virF, the virB and the VirG promoters demonstrates, in agreement with computer predictions, that they have an intrinsically curved structure, confirming the preference of H-NS for bent DNA. In vivo transcriptional analysis of virF mRNA shows that H-NS negatively controls the expression of virF at 30 degrees C. The expression of a virF-lacZ translational fusion in E.coli wild type and in an hns-defective derivative grown at 30 degrees or 37 degrees C and at pH 6.0 or 7.0 indicates that, in the absence of H-NS, virF expression becomes insensitive to temperature and to limited pH changes. Our results strongly suggest that H-NS controls virF expression by binding to the virF promoter and by repressing its expression at low temperature and at low pH.


Asunto(s)
Proteínas Bacterianas/biosíntesis , Proteínas de Unión al ADN/metabolismo , Escherichia coli/genética , Proteínas Represoras/metabolismo , Shigella/genética , Factores de Virulencia , Frío , ADN Bacteriano/química , Escherichia coli/patogenicidad , Regulación Bacteriana de la Expresión Génica , Concentración de Iones de Hidrógeno , Conformación de Ácido Nucleico , Regiones Promotoras Genéticas , Unión Proteica , Shigella/patogenicidad , Transcripción Genética
10.
J Pediatr Surg ; 36(5): 700-5, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11329569

RESUMEN

BACKGROUND/PURPOSE: Nitric oxide (NO) mediates enteric smooth muscle relaxation and mucosal protection. The authors have identified an ontogenically determined pattern of enteric NO neural maturation that may render the distal gut of premature piglets susceptible to injury. METHODS: NO synthase (cNOS and iNOS) activities were measured in the developing piglet gut wall and compared with gut from an intraluminal model of necrotizing enterocolitis (NEC) at different times. RESULTS: In premature animals, iNOS activity was significantly higher 3 hours after NEC induction compared with similarly treated 3-day-old piglets. INOS levels continued to rise 6 hours after NEC induction in prematures. Premature animals (labor induced by prostaglandins) failed to show such a rise in iNOS. In 3 day olds, iNOS levels increased significantly 16 hours after injury compared with the 3-hour group. CONCLUSIONS: iNOS production increases in premature piglets with NEC compared with full-term NEC animals and continues to rise in the presence of intestinal damage regardless of developmental status. Maternal administration of prostaglandins attenuates this rise in iNOS activity. Elevated NO production in premature gut may contribute to increased susceptibility to damage in NEC.


Asunto(s)
Animales Recién Nacidos/metabolismo , Modelos Animales de Enfermedad , Enterocolitis Necrotizante/metabolismo , Mucosa Intestinal/metabolismo , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico/metabolismo , Trabajo de Parto Prematuro/metabolismo , Factores de Edad , Animales , Susceptibilidad a Enfermedades , Femenino , Edad Gestacional , Trabajo de Parto Prematuro/tratamiento farmacológico , Embarazo , Prostaglandinas/uso terapéutico , Porcinos , Factores de Tiempo
11.
J Pediatr Surg ; 23(8): 762-5, 1988 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-2845044

RESUMEN

A retrospective analysis, from 1965 to 1987, of 22 patients less than 18 years of age undergoing thoracotomy for pulmonary metastases from previously diagnosed malignancy, was performed. There were 15 males and seven females whose ages ranged from 8 months to 17, years. Ten patients had primary osteogenic sarcoma, five had Wilms' tumor, and seven had miscellaneous other tumors. A total of 41 thoracotomies were performed with no mortality. The overall survival rate was 54.5%, with an average survival of 6.2 years after initial diagnosis. The osteosarcoma group had a 50% survival rate after an average of 62 months from initial diagnosis, while the Wilms' tumor group had an 80% survival rate with a 100-month average. The remaining seven patients had a 29% average survival rate 62 months after diagnosis. Of the 12 patients undergoing wedge resections, two died upon follow-up 20 and 21 months after initial diagnosis. As opposed to the survivors in this group, both required more than four wedge resections upon initial thoracotomy. Two patients requiring extended resections, one for Ewing's sarcoma and one for hepatoblastoma, died 35 and 3 months after diagnosis, respectively. Of the eight patients undergoing lobectomy and/or segmentectomy, 75% died an average of 31.3 months after diagnosis. Ten patients had two or more thoracotomies for an average of 2.9, with a 40% survival rate. Of the 27% who presented with initial bilateral lung metastases, 33% survived. Forty-five percent of patients had a tumor-free interval of less than 12 months prior to thoracotomy, resulting in a 60% mortality rate.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Neoplasias Pulmonares/secundario , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/cirugía , Masculino , Osteosarcoma/mortalidad , Osteosarcoma/secundario , Osteosarcoma/cirugía , Tumor de Wilms/mortalidad , Tumor de Wilms/secundario , Tumor de Wilms/cirugía
12.
J Pediatr Surg ; 26(11): 1334-6, 1991 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1812270

RESUMEN

Sirenomelia, or the mermaid syndrome, is the most extreme example of the caudal regression syndrome. It invariably presents with lower limb fusion, sacral and pelvic bony anomalies, absent external genitalia, anal imperforation, and renal agenesis or dysgenesis. Because of the resultant oligohydramnios, these infants most often have Potter's facies and pulmonary hypoplasia. There are approximately 300 cases reported in the literature, 15% of which are associated with twinning, most often monozygotic. The syndrome of caudal regression is thought to be the result of injury to the caudal mesoderm early in gestation. It has been suggested that the association of the most extreme form of caudal regression, sirenomelia, with monozygotic twinning may represent developmental arrest of the primitive streak, with creation of a second primitive streak that gives rise to the usually normal twin. The embryology of the various presentations of the caudal regression syndrome may be further delineated by studying infants with this dramatic and fatal syndrome.


Asunto(s)
Enfermedades en Gemelos , Ectromelia , Gemelos Monocigóticos , Humanos , Recién Nacido , Masculino
13.
J Pediatr Surg ; 30(8): 1138-42, 1995 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7472967

RESUMEN

UNLABELLED: The most common risk factors for the development of necrotizing enterocolitis (NEC) are prematurity and enteral feeding. Most models of NEC involve ischemic insult resulting in generalized necrosis, different from the classical ileocecal predilection of NEC. This anatomic predisposition is explained by dysmotility of immature gut, leading to bacterial overgrowth in the terminal ileum and colon. Infant formula containing lactose as the sole carbohydrate source overwhelms partially developed lactase activity, allowing enteric bacteria to ferment excess carbohydrate to short-chain fatty acids, decreasing intraluminal gut pH and predisposing to mucosal injury. Impaired clearance of intraluminal contents exacerbates this effect. In the present study the authors used a model of NEC, originally developed in rabbits and based on analysis of intestinal contents of NEC babies, modified and adapted here to neonatal piglets, the gastrointestinal tract of which more closely resembles the human neonate. METHOD: Piglets < 3 days old and 2 weeks old were laparotomized. Loops created from the distal ileum to the proximal colon were injected with isoosmolar acidified casein solution or 0.9% saline. Segments were harvested 3 hours later, sectioned for H&E, and graded from 0 (intact villi) to 4 (transmural necrosis). RESULTS: Acidified casein-induced damage included areas of necrosis, submucosal edema, inflammatory cell infiltrate, and lymphatic distension. In younger animals, lesions were more pronounced (3.25 +/- 0.13 for the < 3-day-old v 2.43 +/- 0.14 for the 2-week-old piglets; P < .005). CONCLUSION: The authors believe that this piglet NEC model most closely approximates human NEC because it incorporates two of the most common risk factors: dysmotility (by creating intestinal loops) and enteral feeding (by intraluminal injection of acidified casein).


Asunto(s)
Modelos Animales de Enfermedad , Enterocolitis Seudomembranosa/etiología , Envejecimiento , Animales , Animales Recién Nacidos , Bacterias/metabolismo , Gluconato de Calcio/administración & dosificación , Gluconato de Calcio/efectos adversos , Caseínas/administración & dosificación , Caseínas/efectos adversos , Enfermedades del Ciego/inducido químicamente , Enfermedades del Ciego/etiología , Enfermedades del Ciego/microbiología , Edema/inducido químicamente , Nutrición Enteral/efectos adversos , Enterocolitis Seudomembranosa/inducido químicamente , Enterocolitis Seudomembranosa/microbiología , Ácidos Grasos Volátiles/metabolismo , Fermentación , Motilidad Gastrointestinal , Humanos , Concentración de Iones de Hidrógeno , Enfermedades del Íleon/inducido químicamente , Enfermedades del Íleon/etiología , Enfermedades del Íleon/microbiología , Mucosa Intestinal/efectos de los fármacos , Sistema Linfático/efectos de los fármacos , Concentración Osmolar , Propionatos/administración & dosificación , Propionatos/efectos adversos , Conejos , Porcinos
14.
J Pediatr Surg ; 30(2): 235-40; discussion 240-1, 1995 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7537808

RESUMEN

UNLABELLED: Although multifactorial in etiology, prematurity and feeding are two of the most common risk factors associated with necrotizing enterocolitis (NEC). To understand the pathogenesis of NEC, the complex interaction between intestinal contents and clearing mechanisms in the immature human gut must be elucidated. Nitric oxide (NO) is a proposed mediator of nonadrenergic noncholinergic neural inhibition, causing relaxation in the gut. In addition to its role as a neuroeffector substance, studies suggest that endogenous formation of NO maintains intestinal mucosal integrity, protecting the gut from blood-borne toxins and tissue-destructive mediators. Thus, NO has a dual role in both gut smooth muscle relaxation and mucosal protection. Because two of the primary risk factors in the development of NEC are prematurity (as it relates to gut dysmotility) and enteral feeding (as it relates to mucosal damage by intraluminal substrate), the authors chose to investigate the role of NO in the pathogenesis of NEC induced by intraluminal injection of acidified casein solution in neonatal piglets. METHODS: Having confirmed the consistent induction of NEC both macroscopically and histologically with this model (n = 32), the following were undertaken. Neonatal piglets (< 3 days old) were laparotomized, and intestinal loops were created from the terminal ileum to the proximal colon. The loops were injected with acidified casein solution and separated by saline-injected control loops. When the abdomen was closed, a continuous peripheral intravenous infusion of L-arginine, an NO synthase substrate (600 mg/kg/h [n = 6]), or N-omega-nitro-L-arginine methyl ester (L-NAME), an NO synthase inhibitor (20 mg/kg/h [n = 6]), was begun. Gut segments were harvested 3 hours later and processed for evaluation of the extent of necrosis. RESULTS: Macroscopically, the L-NAME-treated group showed areas of hemorrhagic necrosis in the NEC-induced loops. The L-arginine-treated group had greatly diminished or virtually absent lesions. H&E-stained sections were graded microscopically, using a scale from 0 to 4, ranging from intact villi (grade 0) to transmural necrosis (grade 4). In the untreated NEC group, intestinal damage in the acidified casein loops was exhibited by areas of necrosis (extending, in some cases, transmurally), submucosal edema, and inflammatory cell infiltrate (average grade, 3.5). In the L-NAME-treated group, the intestinal damage was similar to that of the NEC-induced group (average grade, 3.5), but also presented with marked hemorrhagic congestion. In the L-arginine group, NEC-induced tissue damage was greatly attenuated, with necrosis limited primarily to the villus tips (average grade, 1). Nevertheless, inflammatory cell infiltrate and mild submucosal edema were still present. CONCLUSION: Continuous intravenous infusion with the NO synthase substrate L-arginine markedly attenuates intestinal injury in this neonatal piglet model of NEC. Intravenous administration of the NO synthase inhibitor L-NAME causes hemorrhagic congestion of the gut wall. Based on these findings, the authors propose that treatment with the amino acid L-arginine should be considered as a potential therapeutic modality for NEC.


Asunto(s)
Arginina/uso terapéutico , Enterocolitis Seudomembranosa/terapia , Aminoácido Oxidorreductasas/metabolismo , Animales , Caseínas , Modelos Animales de Enfermedad , Enterocolitis Seudomembranosa/inducido químicamente , Enterocolitis Seudomembranosa/fisiopatología , Motilidad Gastrointestinal , Infusiones Intravenosas , Mucosa Intestinal/fisiopatología , Óxido Nítrico Sintasa , Porcinos
15.
J Pediatr Surg ; 22(8): 710-2, 1987 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-2958614

RESUMEN

Between January 1, 1971 and December 31, 1985, 59 cases of gastroschisis were treated at Hôpital Sainte-Justine in Montreal. In the period before 1978, 6 of 19 patients (31.6%) were closed primarily at the time of surgery and 13 of 19 patients (68.4%) had silon pouch closure. After 1978, 33 of 40 patients (82.5%) had primary closure and 7 of 40 (17.5%) had a silon pouch. Our overall mortality rate was 13.6%. The complication rate for the primary closure group was 25.6% with a 12.8% (5/39) mortality rate, interestingly, in the higher birth weight group. Those closed with a silon pouch had a 75% complication rate, mostly infectious, with 15% mortality. Neither low birth weight nor gestational age influenced mortality. A significant difference in the length of hospital stay was observed. This was 33.6 days for the primary closures and 56 days for the silon pouch closures. Our series demonstrates a definite favorable trend in the results of treatment of this malformation. The most important factor affecting these results is a change in surgical approach. Primary abdominal wall closure, being usually possible, should always be attempted. We also note an association between high birth weight and death due to bowel dysmotility.


Asunto(s)
Músculos Abdominales/anomalías , Músculos Abdominales/cirugía , Enfermedades en Gemelos , Femenino , Estudios de Seguimiento , Humanos , Recién Nacido , Tiempo de Internación , Masculino , Edad Materna , Mortalidad , Complicaciones Posoperatorias/epidemiología
16.
J Pediatr Surg ; 24(10): 988-91, 1989 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-2809973

RESUMEN

Between 1967 and 1987, 26 patients with bronchogenic cysts were treated in our institution: 15 females and 11 males, ranging in age from 2 months to 14 years (average 6 years, 4 months). Only four patients (15%) were 1 year old or less. Seven patients presented with asymptomatic lesions discovered on chest film. Nineteen patients presented with respiratory symptoms. Of note are the four patients aged 1 year or less, who presented with dyspnea and cyanotic spells. Only one of them presented with dysphagia. All patients underwent routine chest films and tomography and, later, computed tomography (CT) scan of the thorax once the study became available. Barium esophagogram and bronchoscopy were performed as required. Contrary to what has been published concerning the intraparenchymal location of bronchogenic cysts, the majority of the cysts (65%) were located in the mediastinum, usually in close proximity to the carina, mainstem bronchi, trachea, esophagus, or pericardium. Only 27% (7 of 26) were intraparenchymal, and 8% (2 of 26) were situated in the inferior pulmonary ligament. A correct preoperative diagnosis was made in 19 patients (73%). Intrapulmonary lesions were removed by segmentectomy or lobectomy. Cysts located elsewhere were simply excised. Among the cysts adhering to the trachea, 50% (two of four) required suture of the membranous trachea after excision. Postoperative complications included one pneumonia, which responded to antibiotics, and one transient paresis of the right phrenic nerve. Follow-up averaged 17 months (range, 0 to 17 years). No sequelae were noted and all patients were cured.


Asunto(s)
Quiste Broncogénico/cirugía , Adolescente , Quiste Broncogénico/diagnóstico , Niño , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Lactante , Masculino , Toracotomía
17.
J Pediatr Surg ; 25(11): 1143-6, 1990 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-2273428

RESUMEN

Malignant thymomas are extremely rare in children, with only 27 cases reported thus far in the pediatric surgical literature. We report four additional cases diagnosed at this institution over the past 20 years (ages 3 to 14 years). Clinical presentations included superior vena cava syndrome, cough, dyspnea, cyanosis, enlarging mediastinal mass, spontaneous pneumothorax, and pleuropericardial effusion. Three patients underwent incomplete resection of the mass or biopsy because of "unresectability" and were treated with radiotherapy and adjunctive chemotherapy. One patient underwent near complete macroscopic resection as well as radiotherapy and chemotherapy. All patients died at intervals ranging from 6 months to 2 1/2 years after diagnosis. Three patients were found to have metastatic disease prior to death or at autopsy. In one case, the initial pathological diagnosis was lymphocytic thymoma. After ultrastructural studies were performed, the diagnosis was changed to thymic T-cell lymphoma. This patient subsequently developed acute lymphoblastic leukemia 3 months after surgical resection followed by radiotherapy. Malignant thymomas are highly aggressive tumors in children. A radical surgical approach with complete excision of the tumor and contiguous structures in continuity, with adjunctive radiotherapy and chemotherapy remains the only hope for survival in children with these rare lesions.


Asunto(s)
Timoma/patología , Neoplasias del Timo/patología , Adolescente , Preescolar , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Invasividad Neoplásica , Timoma/mortalidad , Timoma/terapia , Neoplasias del Timo/mortalidad , Neoplasias del Timo/terapia
18.
J Pediatr Surg ; 25(11): 1183-4, 1990 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-2177105

RESUMEN

This is the case report of a 4-year-old white boy who was diagnosed as having acute lymphoblastic leukemia (ALL) in November 1985. While in remission and on maintenance chemotherapy, he developed a primary Epstein-Barr virus (EBV) respiratory infection in October 1986. On October 27, 1986 a plain abdominal radiograph taken for abdominal distention showed free air. At celiotomy, multiple nodules were noted to stud the small bowel. Central necrosis of these nodules with perforations were present in the distal small bowel. Resections and end-to-end anastomoses were performed. Three days later the patient again had a similar acute abdominal episode. At reexploration, similar lesions in the liver, kidney, duodenum, proximal jejunum, and colon were found. Liver biopsy as well as intestinal resections and end-to-end anastomoses were performed, along with a loop ileostomy. Polymorphic B-cell lymphoma positive for EBV was found in the specimens. After cessation of chemotherapy and institution of abdominal radiotherapy, the hepatic and renal lesions were seen to resolve on computed tomography scan. The patient's course was complicated by the development of cervical and mediastinal abscesses that were drained, and E coli sepsis accompanied by chronic diarrhea requiring intravenous hyperalimentation. By January 1988, he appeared to be recovering. His ileostomy was closed in March 1988. Despite cessation of chemotherapy since October 1986, the patient is now well and in complete remission.


Asunto(s)
Herpesvirus Humano 4 , Neoplasias Intestinales/complicaciones , Perforación Intestinal/etiología , Linfoma de Células B/complicaciones , Leucemia-Linfoma Linfoblástico de Células Precursoras , Infecciones Tumorales por Virus/complicaciones , Preescolar , Humanos , Enfermedades del Íleon/etiología , Enfermedades del Yeyuno/etiología , Masculino
19.
J Pediatr Surg ; 28(9): 1133-6, 1993 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8308677

RESUMEN

Nine children (6 boys, 3 girls) were diagnosed with a primary endobronchial or pulmonary parenchymal neoplasm. The average age at diagnosis was 9 years. Presenting complaints included cough (7), fever (5), pulmonary infection (3), respiratory distress (3), weight loss (2), pain (2), and hemoptysis (1). Pulmonary x-rays showed persistent atelectasis, pneumonic infiltrates or mass lesions. A computed tomography scan was performed in 8. Five of six endobronchial tumors were diagnosed with bronchoscopy and biopsy. Treatment consisted of thoracotomy and pulmonary resection in 7 cases and laser resection in 2. The pathologic diagnoses were bronchial carcinoid (3), bronchial mucoepidermoid carcinoma (1), inflammatory pseudotumor (plasma cell granuloma) of the bronchus (2) and of the lung parenchyma (1), fibrosarcoma (1), and rhabdomyosarcoma (1). Postoperative chemotherapy was given only to the patient with pulmonary rhabdomyosarcoma; this child died. One child has developed a local recurrence while 7 children are alive and free of disease at an average of 2.4 years postresection. Pulmonary neoplasms are unusual in the pediatric age group and represent a wide spectrum of pathology. Including the present series, 383 tumors have been described. Seventy-six percent were malignant. Early investigation and surgical intervention are essential in children with persistent pulmonary symptoms or x-ray abnormalities. In most cases, the prognosis is excellent with complete surgical resection; however, malignancies other than bronchial adenoma are associated with significantly mortality.


Asunto(s)
Neoplasias de los Bronquios/epidemiología , Neoplasias Pulmonares/epidemiología , Granuloma de Células Plasmáticas del Pulmón/epidemiología , Neoplasias de los Bronquios/diagnóstico , Neoplasias de los Bronquios/cirugía , Tumor Carcinoide/diagnóstico , Tumor Carcinoide/epidemiología , Tumor Carcinoide/cirugía , Niño , Femenino , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/cirugía , Masculino , Granuloma de Células Plasmáticas del Pulmón/diagnóstico , Granuloma de Células Plasmáticas del Pulmón/cirugía
20.
J Pediatr Surg ; 35(5): 696-8, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10813327

RESUMEN

Surgical repair of large umbilical hernias may present a challenging surgical problem. The currently described surgical techniques often yield disappointing results. The authors describe a new technique that allows for the repair of the fascial defect and the creation, with the use of a square cutaneous flap, of a neoumbilicus with sufficient depth and a good cosmetic appearance.


Asunto(s)
Procedimientos Quirúrgicos del Sistema Digestivo/métodos , Hernia Umbilical/cirugía , Población Negra , Niño , Preescolar , Estética , Femenino , Estudios de Seguimiento , Hernia Umbilical/diagnóstico , Hernia Umbilical/etnología , Humanos , Masculino , Índice de Severidad de la Enfermedad , Colgajos Quirúrgicos , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda