Holmgren's principle of delamination during fin skeletogenesis.

During fin morphogenesis, several mesenchyme condensations occur to give rise to the dermal skeleton. Although each of them seems to create distinctive and unique structures, they all follow the premises of the same morphogenetic principle. Holmgren's principle of delamination was first proposed to describe the morphogenesis of skeletal elements of the cranium, but Jarvik extended it to the development of the fin exoskeleton. Since then, some cellular or molecular explanations, such as the "flypaper" model (Thorogood et al.), or the evolutionary description by Moss, have tried to clarify this topic. In this article, we review new data from zebrafish studies to meet these criteria described by Holmgren and other authors. The variety of cell lineages involved in these skeletogenic condensations sheds light on an open discussion of the contributions of mesoderm- versus neural crest-derived cell lineages to the development of the head and trunk skeleton. Moreover, we discuss emerging molecular studies that are disclosing conserved regulatory mechanisms for dermal skeletogenesis and similarities during fin development and regeneration, which may have important implications in the potential use of the zebrafish fin as a model for regenerative medicine.

Sentinel node biopsy in relation to survival in floor of the mouth carcinoma.

Promising results have been obtained with sentinel node biopsy (SNB) in early oral carcinoma, but the floor of the mouth remains a site at risk of misdiagnosis. A retrospective and prospective study was designed to test the safety of SNB by comparing survival among patients with early stage carcinoma of the floor of the mouth (FOM) undergoing SNB, to a control group managed traditionally by a combination of clinical observation and elective neck dissection (END). A total of 63 patients with early stage carcinoma of the FOM were treated between 1991 and 2005. In the control group, 26 patients were managed with END and nine by close observation. In the test group, 28 patients were managed prospectively with SNB. Regional recurrence occurred in 23% (8/35) of control patients and 25% (7/28) of test patients. Approximately 25% of patients were successfully treated by salvage surgery. Disease-specific survival was 65.5% for control patients and 85% for SNB patients; the difference was not statistically significant. The use of SNB in the management of cancers of the FOM did not adversely affect survival and prevented 69.5% of patients undergoing unnecessary neck dissections, while clinical progress was better in the SNB group than in controls.

Actinotrichia collagens and their role in fin formation.

The skeleton of zebrafish fins consists of lepidotrichia and actinotrichia. Actinotrichia are fibrils located at the tip of each lepidotrichia and play a morphogenetic role in fin formation. Actinotrichia are formed by collagens associated with non-collagen components. The non-collagen components of actinotrichia (actinodins) have been shown to play a critical role in fin to limb transition. The present study has focused on the collagens that form actinotrichia and their role in fin formation. We have found actinotrichia are formed by Collagen I plus a novel form of Collagen II, encoded by the col2a1b gene. This second copy of the collagen II gene is only found in fishes and is the only Collagen type II expressed in fins. Both col1a1a and col2a1b were found in actinotrichia forming cells. Significantly, they also expressed the lysyl hydroxylase 1 (lh1) gene, which encodes an enzyme involved in the post-translational processing of collagens. Morpholino knockdown in zebrafish embryos demonstrated that the two collagens and lh1 are essential for actinotrichia and fin fold morphogenesis. The col1a1 dominant mutant chihuahua showed aberrant phenotypes in both actinotrichia and lepidotrichia during fin development and regeneration. These pieces of evidences support that actinotrichia are composed of Collagens I and II, which are post-translationally processed by Lh1, and that the correct expression and assembling of these collagens is essential for fin formation. The unique collagen composition of actinotrichia may play a role in fin skeleton morphogenesis.

[What can we expect of Collaborative Review Groups of Cochrane Collaboration in neuropaediatrics?]. / Qué podemos esperar de los Grupos Colaboradores de Revisión de la Colaboración Cochrane en neuropediatría?

INTRODUCTION: Cochrane Collaboration (CC) contains detailed, critical and up-to-date systematic reviews (SR) of the best scientific evidence available. AIM: To analyse the bibliometric characteristics of the SR related to paediatric neurology published in the 50 Collaborative Review Groups (CRG) of the CC. MATERIALS AND METHODS: Bibliometric analysis of the Database of Systematic Reviews in Cochrane Library, Issue 2, 2005 (n = 2.231 SR). The variables recorded were: number of SR and protocols in any CRG, authors and clusters of secondary research, dates (late review and update), type of study, critical review of the SR and conclusions. RESULTS: Nine published SR about neuropaediatrics: the Epilepsy Group (24 SR), the Neuromuscular Disease Group (16), the Neonatal Group (16), the Developmental, Psychosocial and Learning Problems Group (10), the Pain, Palliative Care and Supportive Care Group (4), the Movement Disorders Group (3), the Injuries Group (3), the Infectious Disease Group (3) and the Acute Respiratory Infections Group (2). The three main thematic areas were treatment of epilepsy (pharmacologic and non-pharmacologic), neonatal neurology (mainly intraventricular haemorrhage and perinatal asphyxia) and miscellanea (autism spectrum disorder, headache, cerebral palsy, myasthenia gravis, Guillain-Barre syndrome, Bell's palsy and bacterial meningitis). All the SR were about treatment interventions. CONCLUSIONS: Paediatric neurology SR are infrequent (3.6% of the 2.231 SR published in CC), and helps an evidence-based decision-making in a few areas: pharmacologic treatment of epilepsy, management of intraventricular haemorrhage of preterm infants and bacterial meningitis. Many therapies in paediatric neurology persist with no supporting evidence, and we detected no SR about important neurological issues in childhood as attention-deficit hyperactivity disorder, mental retardation and hypotonia.

¿Qué podemos esperar de los Grupos Colaboradores de Revisión de la Colaboración Cochrane en neuropediatría? / What can we expect of Collaborative Review Groups of Cochrane collaboration in Neuropaediatrics?

Introducción. La Colaboración Cochrane (CC) se fundamentaen revisiones sistemáticas (RS) exhaustivas, críticas y actualizadasde la mejor evidencia científica disponible. Objetivo.Analizar las características bibliométricas de las RS relacionadascon la neuropediatría publicadas en los 50 Grupos Colaboradoresde Revisión (GCR) de la CC. Materiales y métodos. Análisis bibliométricode la Base de Datos de RS en la Cochrane Library, Issue 2,2005 (n = 2.231 RS). Variables analizadas: número de RS y protocolosen cada GCR, autores y grupos de investigación secundaria,fechas (última revisión y actualización), tipo de estudio, valoracióncrítica de la RS y conclusiones. Resultados. Nueve GCR presentanRS sobre neuropediatría: 24 en Epilepsy Group, 16 en NeuromuscularDisease Group, 16 en Neonatal Group, 10 en Developmental,Psychosocial and Learning Problems Group, cuatro RS en CochranePain, Palliative Care and Supportive Care Group, tres en MovementDisorders Group, tres en Injuries Group, tres en Cochrane InfectiousDisease Group y dos en Cochrane Acute Respiratory InfectionsGroup. Las tres áreas temáticas principales detectadas fuerontratamiento de la epilepsia (farmacológico y no farmacológico),patología neurológica neonatal (principalmente hemorragia intraventriculary asfixia perinatal) y miscelánea (espectro autista, cefalea,parálisis cerebral infantil, miastenia grave, síndrome de Guillain-Barré, parálisis facial de Bell y meningitis bacteriana). Todaslas RS versan sobre intervenciones terapéuticas. Conclusiones. LasRS sobre neuropediatría son escasas (3,6% del total de 2.231 RSpublicadas en CC) y sólo permiten una toma de decisiones basadaen pruebas en algunos temas: tratamiento farmacológico de la epilepsia,manejo de la hemorragia intraventricular del prematuro ymeningitis bacteriana. Muchos tratamientos en neurología pediátricapermanecen sin un soporte de evidencia científica y no se encuentranRS acerca de áreas importantes de la neurología pediátricacomo trastorno por déficit de atención/hiperactividad, retrasomental e hipotonía

Introduction. Cochrane Collaboration (CC) contains detailed, critical and up-to-date systematic reviews (SR) of thebest scientific evidence available. Aim. To analyse the bibliometric characteristics of the SR related to paediatric neurologypublished in the 50 Collaborative Review Groups (CRG) of the CC. Materials and methods. Bibliometric analysis of the Databaseof Systematic Reviews in Cochrane Library, Issue 2, 2005 (n = 2.231 SR). The variables recorded were: number of SR andprotocols in any CRG, authors and clusters of secondary research, dates (late review and update), type of study, critical reviewof the SR and conclusions. Results. Nine published SR about neuropaediatrics: the Epilepsy Group (24 SR), the NeuromuscularDisease Group (16), the Neonatal Group (16), the Developmental, Psychosocial and Learning Problems Group (10), the Pain,Palliative Care and Supportive Care Group (4), the Movement Disorders Group (3), the Injuries Group (3), the InfectiousDisease Group (3) and the Acute Respiratory Infections Group (2). The three main thematic areas were treatment of epilepsy(pharmacologic and non-pharmacologic), neonatal neurology (mainly intraventricular haemorrhage and perinatal asphyxia)and miscellanea (autism spectrum disorder, headache, cerebral palsy, myasthenia gravis, Guillain-Barré syndrome, Bell’s palsyand bacterial meningitis). All the SR were about treatment interventions. Conclusions. Paediatric neurology SR are infrequent(3.6% of the 2.231 SR published in CC), and helps an evidence-based decision-making in a few areas: pharmacologic treatmentof epilepsy, management of intraventricular haemorrhage of preterm infants and bacterial meningitis. Many therapies inpaediatric neurology persist with no supporting evidence, and we detected no SR about important neurological issues in childhoodas attention-deficit hyperactivity disorder, mental retardation and hypotonia

Production of a recombinant human basic fibroblast growth factor with a collagen binding domain.

Basic fibroblast growth factor (bFGF) is a potent in vitro mitogen for capillary endothelial cells, stimulates angiogenesis in vivo, and may participate in tissue repair. Basic FGF is found in abundance in tissues such as brain, kidney, and cartilage. This study reports the expression, purification, and renaturation of a biologically active human basic fibroblast growth factor fusion protein (hbFGF-F1) from Escherichia coli. A prokaryotic expression vector was engineered to produce a tripartite fusion protein consisting of a purification tag, a protease-sensitive linker and collagen binding domain, and a cDNA sequence encoding the active fragment of hbFGF. The expressed hbFGF-F1 and hbFGF-F2 (it contains the collagen binding domain), located in inclusion bodies, were solubilized with 6 M guanidine-HCl and renatured by a glutathione redox system and protracted dialysis under various experimental conditions. The purification of the recombinant proteins was achieved by binding the His-tag of the fusion protein on a nickel-nitrilotriacetic acid metal chelate column. The biological activity of the recombinant growth factor was demonstrated by its ability to stimulate proliferation of human vein endothelial cells, monitored by [3H]thymidine incorporation, where commercial recombinant human bFGF (rhbFGF) served as a positive control. Purified rhbFGF-F1 and rhbFGF-F2 constructs exhibited proliferative activity comparable to commercial rhbFGF. The high-affinity binding was demonstrated by the binding of [3H]collagen to the rhbFGF-F2 protein immobilized on a Ni-nitrilotriacetic acid column. The rhbFGF-F2 fusion protein bound to collagen-coated surfaces with high affinity. Taken together, these results demonstrate that biologically active rhbFGF fusion proteins can be recovered from transformed bacteria by oxidative refolding; thus, providing a means for their high-yield production, purification, and renaturation from microorganisms. Furthermore, we demonstrate that the auxiliary collagen binding domain effectively targets the recombinant growth factor to type I collagen. These studies advance the technology necessary to generate large quantities of targeted bFGF fusion proteins for specific biomedical applications.

[Usefulness of a software package to reduce medication errors in neonatal care]. / Utilidad de una aplicación informática para disminuir errores de tratamiento en neonatología.

BACKGROUND: Many treatment errors in neonatal intensive care units are caused by the need to carry out a sequence of calculations to determine the dose and dilution of the drugs used. OBJECTIVES: To help in this task, we designed a spreadsheet (Neodosis) that helps clinicians and nurses to calculate the doses and standardize the dilutions of some of the drugs most commonly used in resuscitation and neonatal intensive care units. The aim of this study was to verify the usefulness and reliability of this software package. METHODS: A randomized, cross-over, controlled trial was conducted through simulated clinical cases in which the number of errors in the prescription data and the amount of time spent in making calculations, with and without the program, were evaluated. Fifty-four tests were performed by pediatricians, third- and fourth-year pediatric residents, and nurses. RESULTS: Without computer support, all three groups made errors (residents, pediatricians and nurses in descending order). When Neodosis was used, all the medical staff made significantly fewer errors. The greatest reduction was found in errors made by pediatric residents: minor errors decreased from 16 % to 2 % and major errors from 1.6 % to zero. When using the spreadsheet, the time spent by all groups in making the calculations was reduced by between one-third and one-half. CONCLUSIONS: The tests performed with simulated clinical cases revealed that the number of errors made by the healthcare personnel who participated in this study was not inconsiderable. The use of Neodosis helped physicians and nurses to make markedly fewer errors and also saved them time.

Utilidad de una aplicación informática para disminuir errores de tratamiento en neonatología / Usefulness of a software package to reduce medication errors in neonatal care

Antecedentes: Muchos de los errores de tratamiento producidos en las unidades de cuidados intensivos neonatales (UCIN) tienen su origen en la necesidad de efectuar secuencias de cálculos para determinar dosis y diluciones de fármacos. Objetivos: Para ayudar en estas tareas se diseñó una hoja de cálculo (neodosis) que facilita los cálculos y estandariza las diluciones de algunas de las terapias más usadas en reanimación y UCIN. Para evaluar su utilidad se diseñó este trabajo. Métodos: Se efectuó un estudio controlado, cruzado y aleatorizado mediante simulaciones clínicas en las que se evaluó el número de errores y tiempo utilizado en su resolución, con y sin el programa. Fueron realizadas un total de 54 pruebas en las que intervinieron médicos (residentes de tercer y cuarto año y pediatras) y personal de enfermería. Resultados: Sin ayuda de ordenador todos los estamentos cometieron errores (en orden decreciente: residentes, pediatras y enfermería). El conjunto del estamento médico experimentó una reducción significativa de errores con la ayuda informática. El grupo de residentes fue el más beneficiado con su utilización: su porcentaje de errores "menores" pasó del 16 al 2% y el de errores "mayores" del 1,6% a 0. El tiempo empleado por todos los grupos se redujo entre un tercio y la mitad. Conclusiones: El personal asistencial probado cometió un número no insignificante de errores en pruebas de simulación sobre cálculos típicos de UCIN. Neodosis ayudó a médicos y enfermeras a reducir muy sensiblemente estos errores y a emplear menos tiempo en su resolución (AU)

Selection and amplification of a bone marrow cell population and its induction to the chondro-osteogenic lineage by rhOP-1: an in vitro and in vivo study.

The differentiation and maturation of osteoprogenitor cells into osteoblasts are processes which are thought to be modulated by transforming growth factors-beta (TGF-beta) as well as by bone morphogenetic proteins (BMPs). Osteogenic protein-1 (OP-1, also known as BMP-7) is a member of the BMP family, and it is considered to have important regulatory roles in skeletal embryogenesis and bone healing. Rat bone marrow cells were cultured in vitro in a collagen-gel medium containing 0.5% fetal bovine serum (FBS) for 10 days in the presence of 40 ng/ml recombinant human OP-1 (rhOP-1). Under these conditions, survival of the bone marrow cell population was dependent on the presence of rhOP-1. Subsequently, the selected cells were cultured-for 6 days in medium containing 40 ng rhOP-1 and 10% FBS. During the last 2 days, dexamethasone (10(-8) M) and beta-glycerophosphate (2 mM) were added to potentiate osteoinduction. Concomitant with an up-regulation of cell proliferation, DNA synthesis levels, colony number and size were determined. Chondro-osteogenic differentiation in vitro was evaluated in terms of the expression of alkaline phosphatase, the production of osteocalcin and the formation of mineralized matrix. After culturing in vitro, cells were placed inside diffusion chambers or inactivated demineralized bone matrix (DBM) cylinders and implanted subdermically into the backs of old rats for 28 days. Biochemical, histological and immunocytochemical analyses provided evidence of cartilage and osteoid tissue inside the diffusion chambers, whereas bone was also observed inside the DBM implants. In conclusion, this experimental procedure is capable of selecting a cell population from bone marrow which, in the presence of rhOP-1, achieves skeletogenic potential under in vitro as well as in vivo environments.

[Episodic benign unilateral mydriasis. Clinical case in a girl]. / Midriasis unilateral benigna episódica. Caso clínico en una niña.

INTRODUCTION: Pupil asymmetry is an alarm signal which should lead to investigation to rule out severe underlying neurological disorders. Among its causes are tumors, aneurysms and hernia of the uncus. The differential diagnosis should also include other conditions such as Adie's tonic pupil, the Pourfour de Petit syndrome and local disorders such as closed angle glaucoma or segmental spasm of the iris dilator muscle. In practice however, exposure to mydriatic substance is one of the commonest causes. Another cause of this sign is benign episodic unilateral mydriasis. This uncommon condition has been defined as an isolated benign cause of pupil asymmetry. The underlying physiopathology is not always clear and may involve either parasympathetic deficiency or sympathetic hyperactivity affecting the iris. Usually related to migraine, some authors classify it as a limited form of ophthalmoplegic migraine, although some cases have been described with no accompanying headache. CLINICAL CASE: We describe a case of benign episodic unilateral mydriasis in a six-year-old girl who presented with intermittent episodes of pupil asymmetry with no other neurological symptoms. CONCLUSION: We underline the rarity of this condition in children with no simultaneous headache.

Reconstruction of the aesthetic units of the face with microsurgery: experience in five years.

Since the description of the aesthetic units of the face by González-Ulloa, surgical attempts have been made to achieve excellent results with skin grafts, pedicled flaps, and free flaps. At our institution, we preferentially use microsurgical replacement of the aesthetic units independent of the etiology. The objective of this article is to present a retrospective review of the outcome of patients who underwent these procedures. The etiology, the choice of the procedure, and the functional and aesthetic results are assessed. We suggest the main features according to the results obtained. In this retrospective review, 43 procedures in a 5-year period are analyzed and the results reported. We conclude that the operative procedure is both technically simple and effective over the long term.

Hipoglucemia hiperinsulinémica persistente en recién nacido asociada al tratamiento con glimepiride al inicio del embarazo

No disponible

Firing up the front line.

For many organizations, achieving competitive advantage means eliciting superior performance from employees on the front line--the burger flippers, hotel room cleaners, and baggage handlers whose work has an enormous effect on customers. That's no easy task. Front line workers are paid low wages, have scant hope of advancement, and--not surprisingly--often care little about the company's performance. But then how do some companies succeed in engaging the emotional energy of rank-and-file workers? A team of researchers at McKinsey & Company and the Conference Board recently explored that question and discovered that one highly effective route is demonstrated by the U.S. Marine Corps. The Marines' approach to motivation follows the "mission, values, and pride" path, which researchers say is practical and relevant for the business world. More specifically, the authors say the Marines follow five practices: they over-invest in cultivating core value; prepare every person to lead, including front line supervisors; learn when to create teams and when to create single-leader work groups; attend to all employees, not just the top half; and encourage self-discipline as a way of building pride. The authors admit there are critical differences between the Marines and most businesses. But using vivid examples from companies such as KFC and Marriott International, the authors illustrate how the Marines' approach can be translated for corporate use. Sometimes, the authors maintain, minor changes in a company's standard operating procedure can have a powerful effect on front line pride and can result in substantial payoffs in company performance.

Analysis of the mechanism of quinolone resistance in nalidixic acid-resistant clinical isolates of Salmonella serotype Typhimurium.

Over a period of 2.5 years, 42 cases of gastro-enteritis caused by nalidixic acid-resistant Salmonella serotype Typhimurium occurred in Malaga. The epidemiological relationship among the strains involved was investigated by analysis of plasmid profile and of chromosomal DNA by pulsed-field gel electrophoresis (PFGE). Despite having different plasmid profiles, all 42 nalidixic-acid resistant Typhimurium isolates had evolved from one clone as shown by analysis of chromosomal DNA by PFGE. The mechanism of quinolone resistance in these Typhimurium isolates was also investigated. Analysis of outer-membrane proteins and lipopolysaccharide from quinolone-susceptible and resistant clinical isolates tested showed no differences. All nalidixic acid-resistant isolates had MICs for ciprofloxacin of 0.25 mg/L and for nalidixic acid of 1024 mg/L. Polymerase chain reaction fragments of 285 bp, containing the quinolone resistance-determining region of the gyrA gene, and of 237 bp, containing the region of parC homologous to the quinolone resistance-determining region of the gyrA gene, were sequenced. All resistant isolates presented a change at Ser-83 to Phe in the GyrA protein, but no changes were observed in the ParC protein. These findings indicated that this mutation in gyrA plays a major role in the acquisition of nalidixic-acid resistance in clinical isolates of Typhimurium.

Eikenella corrodens skull infection: a case report with review of the literature.

BACKGROUND: Subgaleal abscesses and skull osteomyelitis are very uncommon since the introduction of antibiotics. Eikenella corrodens infection is extremely rare in childhood and has never been reported in calvarial osteomyelitis. METHODS: We present a previously healthy 9-year-old boy, with a history of frontal contusion without injury, who developed E corrodens osteomyelitis of the skull. The radiographic findings are reviewed, including skull films and computed tomographic scans. The patient underwent surgical debridement of the lesion, as well as systemic medical therapy with amoxicillin. We review the medical and surgical therapy for such lesions. The differential diagnosis of a posttraumatic scalp swelling is also reviewed. RESULTS: Good resolution after debridement and antibiotic therapy is reported. CONCLUSIONS: Surgical intervention is emphasized for the removal of bony sequestrum and nonviable bone while maintaining an intact dura.

Incorporation of bromodeoxyuridine in regenerating fin tissue of the goldfish Carassius auratus.

We have investigated the pattern of incorporation of 5-bromo-2'-deoxyuridine-5'-monophosphate (BrdU) by proliferating cells during regeneration of the tail fin of Carassius auratus. Fifteen days after amputation, intraperitoneal injection of a single dose of 0.25 mg/g wet weight of BrdU and subsequent immunocytochemical detection on sections revealed groups of replicating cells in the blastema and epidermis at different proximodistal levels. Proliferating blastemal cells were confined to a crowded, compact distal area that lost its replicative capacity laterally, causing the differentiation of scleroblasts, which synthesize the lepidotrichia hemisegments. Proximally, but centrally located, the blastemal cells did not incorporate BrdU and they differentiated giving rise to the mature intraray connective tissue. An independent cell-proliferation process was noted in the epidermis. The distal cap did not proliferate; the lateral faces of the epidermis showed high rates of cell replication in the central layer at every level of the regenerate rays; quiescent cells remained in the superficial layers. The basal epidermal cells did not incorporate BrdU when actinotrichia were present. The possible role of basal epidermal cells in the synthesis of actinotrichia, the contribution of these collagen macrofibrils to the morphogenetic process, and the different pathways of cell differentiation during fin regeneration are discussed.