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There is an emerging body of evidence showing that young patients, post haematopoietic stem cell transplantation (HSCT), can develop skeletal changes that mimic an osteochondrodysplasia process. The key discriminator is that these children have had otherwise normal growth and skeletal development before the therapeutic intervention (HSCT), typically for a haematological malignancy. Herein we present that case of a boy who underwent HSCT for Haemophagocytic Lymphohistiocytosis (HLH) aged 2 years. Following Intervention with HSCT this boy's growth has severely decelerated (stature less than 1st centile matched for age) and he has developed a spondyloepiphyseal dysplasia.
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Trasplante de Células Madre Hematopoyéticas , Linfohistiocitosis Hemofagocítica , Osteocondrodisplasias , Humanos , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Masculino , Osteocondrodisplasias/genética , Osteocondrodisplasias/patología , Preescolar , Linfohistiocitosis Hemofagocítica/genética , Linfohistiocitosis Hemofagocítica/patología , Linfohistiocitosis Hemofagocítica/etiología , Trastornos del Crecimiento/patología , Trastornos del Crecimiento/etiología , Trastornos del Crecimiento/genéticaRESUMEN
Aims To analyse all paediatric patients who presented with diabetic ketoacidosis (DKA) from 2012 to 2017. Methods A retrospective observational study was carried out analysing all cases of diabetic ketoacidosis admitted to a regional centre from 2012-2017. Results We identified 133 cases of DKA, 81 (61%) were newly diagnosed patients and 52 (39%) were patients with known T1DM. There were 215 new diagnoses of T1DM during the study period giving a DKA rate at diagnosis of 38%. Among the 52 cases with established T1DM, 13 cases (25%) presented in severe DKA and 37 cases (71%) occurred in adolescents aged over 12 years. Precipitating factors included chronic suboptimal control and psychosocial factors (28/52), acute illness (16/52), and pump technical failure (5/52). There were two cases treated for suspected cerebral oedema and one case each of subarachnoid haemorrhage and cardiac arrhythmia. Conclusion The current proportion of new T1DM presenting in DKA is higher than international data. The high frequency of DKA in known T1DM indicates a need for particular focus on adolescents.
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Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/epidemiología , Cetoacidosis Diabética/epidemiología , Cetoacidosis Diabética/etiología , Adolescente , Niño , Preescolar , Femenino , Humanos , Incidencia , Lactante , Recién Nacido , Irlanda/epidemiología , Masculino , Estudios Retrospectivos , Factores de TiempoRESUMEN
Aim Our aim was to design a new insulin prescribing tool in compliance with the Irish Medicines Safety Network recommendations. Methods In 2015, we undertook a review of the existing paediatric subcutaneous insulin-prescribing sheet introduced to Cork University Hospital in 2013. This involved a retrospective analysis of 15 consecutive in-patient insulin prescribing charts and a questionnaire distributed to health professionals. Following this a new insulin prescribing chart was designed and implemented in 2016 and a re-audit was performed in 2017. Results The 2017 re-audit demonstrated that the new insulin chart was viewed as easier (95% of previous users n=18) and safer (n=16) to use. There was less confusion (2017: 28%, n=11/39 vs 2015: 50%, n=17/34 2015) and the ALERT system helped staff standardise hypo/hyperglycaemia management (71%, n=28). Conclusion The new paediatric insulin prescribing chart has improved safety and ease of prescribing insulin. The colour coded quasi graph and ALERT system has made it easier to appreciate capillary blood glucose trends and manage them safely.
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Diabetes Mellitus/tratamiento farmacológico , Insulina/administración & dosificación , Prescripciones/estadística & datos numéricos , Niño , Humanos , Seguridad del Paciente , Estudios RetrospectivosAsunto(s)
COVID-19 , Diabetes Mellitus , Niño , Humanos , Instituciones de Atención Ambulatoria , Teléfono , PadresRESUMEN
OBJECTIVE: To establish the prevalence of paediatric Type 2 diabetes in the Republic of Ireland and describe patient demographics, initial presentation, management, outcomes, comorbidities and complications. METHODS: Using a standardized proforma we conducted a cross-sectional survey of children and adolescents aged < 16 years with a diagnosis of Type 2 diabetes between October and December 2015 in each of the 19 centres in the Republic of Ireland responsible for the care of children with diabetes. RESULTS: Twelve cases of Type 2 diabetes were identified, giving a prevalence in children aged <16 years of 1.2/100 000 (95% CI 0.6 to 2). Six of these children (50%) were white, two (33%) of whom were members of the travelling community. Four (33%) were of black ethnicity. The prevalence of Type 2 diabetes in traveller children was 16.1/100 000 (95% CI 1.9 to 58.1) and was similar to that in black children, a known high-risk group, which was 13.3/100 000 (95% CI 3.6 to 34.1). The median current HbA1c value was 51 mmol/mol (6.8%) and four (33%) of the children achieved the International Society for Pediatric and Adolescent Diabetes target HbA1c of ≤48 mmol/mol (6.5%). Seven (59%) children were managed on metformin monotherapy, three (25%) were managed on insulin and metformin in combination, and two (16%) were receiving dietary management. CONCLUSION: This was the first national study to estimate the prevalence of childhood Type 2 diabetes in Ireland. Despite their white ethnicity, traveller children appear to be a high-risk group, but this finding requires further study.
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Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/epidemiología , Hipoglucemiantes/uso terapéutico , Adolescente , Niño , Preescolar , Estudios Transversales , Femenino , Humanos , Lactante , Insulina/uso terapéutico , Irlanda/epidemiología , Masculino , Metformina/uso terapéutico , PrevalenciaRESUMEN
Care of the patient with a presumed life- or limb-threatening lower extremity wound poses many challenges. The mindset regarding potential outcomes of such conditions is mostly driven by the experiences and expertise of those providing the care. This mindset generally appears as two primary actions presented to the afflicted patient: attempted resolution of the problem via medical, surgical or combination treatment, with the hope of low recurrence risk, or exacerbation and amputation-amputations at a level sufficient to, at least in the mind of the surgeon, eliminate the problem. Achieving the former outcome is dependent on a number of factors associated with both patient and caregiver. If healing is achieved, the secondary goal of prevention of recurrence may be no less arduous, with failure most likely resulting in amputation. Clearly, these considerations appear to be based more on the health professionals perception, of the patient's physical and medical status rather than on patient-centred considerations. This article will review considerations and recommendations for lower extremity amputation, and the short- and long-term implications. Based on our research, there is clear need for a set of criteria against which to weigh not just the medical issues, but also definitive patient-centred issues when considering a lower extremity amputation. We offer a set of patient-centred, easily verified and recognised criteria that we believe addresses this need. The goal of the Miller-Newgent Amputation Scale (MENACE) is to provide a decision base from which to consider and evaluate all factors in determining the need for a lower extremity amputation. This involves identification of patient-centred issues, which are likely to produce satisfactory short- and long-term physical and quality-of-life outcomes if the amputation does proceed.
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Traumatismos de la Pierna/cirugía , Índice de Severidad de la Enfermedad , Amputación Quirúrgica , Técnicas de Apoyo para la Decisión , Humanos , Recuperación del Miembro , Atención Dirigida al Paciente , Factores de Riesgo , Cicatrización de HeridasRESUMEN
Many countries have established regulations regarding growth hormone (GH) treatment in children, to standardise care and reduce cost. In this study, we describe current practice in Ireland surrounding child measurement and the approach to diagnosis of GH deficiency. A questionnaire was sent to 139 paediatricians in Ireland and 35 (9 paediatric endocrinologists) responded. Only 13 (37.1%) use the recommended 2-person technique for measuring children under 2. Amongst GH prescribers, there were a variety of GH Stimulation Tests used, sex steroid priming was used by 8 (80%) and the general cut off for a passed test was consistent (7ng/ml). Brand rotation (n=5, 50%) and cost (n=3, 30%) were the most common criteria for deciding the formulation of GH prescribed. We recommend that departments review their child measurement technique and equipment. We also advise the establishment of national guidelines for the use of GH, and a prospective registry for GH treated children.
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Combined pituitary hormone deficiency (CPHD) in man denotes impaired production of growth hormone (GH) and one or more of the other five anterior pituitary hormones. Mutations of the pituitary transcription factor gene POU1F1 (the human homologue of mouse Pit1) are responsible for deficiencies of GH, prolactin and thyroid stimulating hormone (TSH) in Snell and Jackson dwarf mice and in man, while the production of adrenocorticotrophic hormone (ACTH), luteinizing hormone (LH) and follicle stimulating hormone (FSH) is preserved. The Ames dwarf (df) mouse displays a similar phenotype, and appears to be epistatic to Snell and Jackson dwarfism. We have recently positionally cloned the putative Ames dwarf gene Prop1, which encodes a paired-like homeodomain protein that is expressed specifically in embryonic pituitary and is necessary for Pit1 expression. In this report, we have identified four CPHD families with homozygosity or compound heterozygosity for inactivating mutations of PROP1. These mutations in the human PROP1 gene result in a gene product with reduced DNA-binding and transcriptional activation ability in comparison to the product of the murine df mutation. In contrast to individuals with POU1F1 mutations, those with PROP1 mutations cannot produce LH and FSH at a sufficient level and do not enter puberty spontaneously. Our results identify a major cause of CPHD in humans and suggest a direct or indirect role for PROP1 in the ontogenesis of pituitary gonadotropes, as well as somatotropes, lactotropes and caudomedial thyrotropes.
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Proteínas de Homeodominio/genética , Hipopituitarismo/genética , Proteínas de la Membrana , Hormonas Hipofisarias/deficiencia , Proteínas de Saccharomyces cerevisiae , Factores de Transcripción/genética , Adolescente , Adulto , Secuencia de Aminoácidos , Animales , Proteínas Portadoras/genética , Niño , Secuencia Conservada , Enanismo/genética , Femenino , Hormona del Crecimiento/deficiencia , Heterocigoto , Proteínas de Homeodominio/biosíntesis , Proteínas de Homeodominio/química , Homocigoto , Hormona de Crecimiento Humana/deficiencia , Humanos , Masculino , Ratones , Ratones Mutantes , Datos de Secuencia Molecular , Linaje , Proteínas de Transferencia de Fosfolípidos , Prolactina/deficiencia , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Tirotropina/deficiencia , Factores de Transcripción/biosíntesis , Factores de Transcripción/químicaRESUMEN
BACKGROUND: Rare diseases (RDs) are often complex, serious, chronic and multi-systemic conditions, associated with physical, sensory and intellectual disability. Patients require follow-up management from multiple medical specialists and health and social care professionals involving a high level of integrated care, service coordination and specified care pathways. METHODS AND OBJECTIVES: This pilot study aimed to explore the best approach for developing national RD care pathways in the Irish healthcare system in the context of a lack of agreed methodology. Irish clinical specialists and patient/lived experience experts were asked to map existing practice against evidence-based clinical practice guidelines (CPGs) and best practice recommendations from the European Reference Networks (ERNs) to develop optimal care pathways. The study focused on the more prevalent, multisystemic rare conditions that require multidisciplinary care, services, supports and therapeutic interventions. RESULTS: 29 rare conditions were selected across 18 ERNs, for care pathway development. Multidisciplinary input from multiple specialisms was relevant for all pathways. A high level of engagement was experienced from clinical leads and patient organisations. CPGs were identified for 26 of the conditions. Nurse specialist, Psychology, Medical Social Work and Database Manager roles were deemed essential for all care pathways. Access to the therapeutic Health Service Professionals: Physiotherapy, Occupational Therapy, and Speech and Language Therapy were seen as key requirements for holistic care. Genetic counselling was highlighted as a core discipline in 27 pathways demonstrating the importance of access to Clinical Genetics services for many people with RDs. CONCLUSIONS: This study proposes a methodology for Irish RD care pathway development, in collaboration with patient/service user advocates. Common RD patient needs and health care professional interventions across all pathways were identified. Key RD stakeholders have endorsed this national care pathway initiative. Future research focused on the implementation of such care pathways is a priority.
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Vías Clínicas , Enfermedades Raras , Atención a la Salud , Humanos , Irlanda , Proyectos Piloto , Enfermedades Raras/terapiaRESUMEN
We sought to evaluate the oral health status of children born small for gestational age (SGA). Children now aged 4-8 years who were born SGA (birth weight < -2 SDS) were examined using standardised criteria. The parents completed a structured oral health questionnaire. Twenty females and 25 males, mean age 72.1 months, and mean birth weight 2.1 kg, participated in the study. Poor appetite was a concern; 32 (71%) children snacked between meals and 14 (30%) used carbonated beverages more than 3 times daily. Erosion was present in 9 (20%) children. Dental decay occurred in 22 (47%) children with 92% being untreated. Eight children had more than 5 decayed teeth. It is essential that clinicians working with children born SGA include oral health within the general health surveillance and refer these children for a dental assessment within the first 2 years to support parents in establishing safe feeding patterns for their children.
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Recién Nacido Pequeño para la Edad Gestacional , Salud Bucal , Niño , Preescolar , Caries Dental/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Recién Nacido , Masculino , Erosión de los Dientes/epidemiologíaRESUMEN
Axon pathfinding relies on the ability of the growth cone to detect and interpret guidance cues and to modulate cytoskeletal changes in response to these signals. We report that the murine POU domain transcription factor Brn-3.2 regulates pathfinding in retinal ganglion cell (RGC) axons at multiple points along their pathways and the establishment of topographic order in the superior colliculus. Using representational difference analysis, we identified Brn-3.2 gene targets likely to act on axon guidance at the levels of transcription, cell-cell interaction, and signal transduction, including the actin-binding LIM domain protein abLIM. We present evidence that abLIM plays a crucial role in RGC axon pathfinding, sharing functional similarity with its C. elegans homolog, UNC-115. Our findings provide insights into a Brn-3.2-directed hierarchical program linking signaling events to cytoskeletal changes required for axon pathfinding.
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Axones/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas de Homeodominio , Factores de Transcripción/metabolismo , Vías Visuales/embriología , Vías Visuales/metabolismo , Animales , Axones/ultraestructura , Comunicación Celular/genética , Embrión de Pollo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/farmacología , Perfilación de la Expresión Génica/métodos , Conos de Crecimiento/metabolismo , Proteínas con Dominio LIM , Ratones , Ratones Noqueados , Proteínas de Microfilamentos/genética , Proteínas de Microfilamentos/metabolismo , Datos de Secuencia Molecular , Nervio Óptico/patología , Enfermedades del Nervio Óptico/genética , Enfermedades del Nervio Óptico/patología , Estructura Terciaria de Proteína , Retina/patología , Células Ganglionares de la Retina/citología , Células Ganglionares de la Retina/metabolismo , Homología de Secuencia de Aminoácido , Transducción de Señal/genética , Colículos Superiores/citología , Colículos Superiores/embriología , Colículos Superiores/metabolismo , Factor de Transcripción Brn-3B , Factores de Transcripción/genética , Factores de Transcripción/farmacología , Vías Visuales/citologíaRESUMEN
Human intraepithelial lymphocytes (IEL), predominantly CD8+ T-lymphocytes located between intestinal epithelial cells (EC), may represent the first-line immune defense against colon cancer. The mechanism by which IEL bind to the colon cancer line, DLD-1, was evaluated. A larger fraction of IEL than peripheral blood mononuclear cells bound to DLD-1 monolayers (25 +/- 16 versus 8 +/- 4% binding, P < 0.05). Binding increased when DLD-1 monolayers were incubated with interferon-gamma but not with tumor necrosis factor-alpha. Similar numbers of IEL adhered to EC tumors, HT-29 and 5637, and the non-EC tumor, A375, but fewer bound to nonmalignant smooth muscle (HISM) and fibroblast (KD) lines (P < 0.01). Binding of IEL to DLD-1 was reduced by monoclonal antibodies to HML-1 and CD11a (47 +/- 9 and 26 +/- 13% inhibition, respectively) and was completely eliminated by both combined (93 +/- 4% inhibition). Anti-HML-1 also inhibited the binding of IEL to other EC tumors but did not affect binding to non-EC tumors or fibroblasts. To conclude, the binding of IEL to EC tumors is mediated by HML-1 and CD11a [A. I. Roberts, S. M. O'Connell, and E. C. Ebert. Binding of intraepithelial lymphocytes to colon cancer cells is mediated by HML-1 and LFA-1 (abstract). Gastroenterology, 102: A685, 1992].
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Antígenos de Neoplasias/inmunología , Neoplasias del Colon/inmunología , Antígeno-1 Asociado a Función de Linfocito/inmunología , Linfocitos T/inmunología , Adhesión Celular/efectos de los fármacos , Adhesión Celular/inmunología , Separación Celular/métodos , Células Epiteliales , Epitelio/inmunología , Humanos , Inmunidad Celular , Interferón gamma/farmacología , Intestinos/citología , Intestinos/inmunología , Linfocitos T/efectos de los fármacosRESUMEN
Treatment of U-937 cells with the cyclic nucleotide analog, dibutyryl cyclic adenosine-3',5'-monophosphate (dBcAMP) induced these cells to differentiate towards granulocytes. dBcAMP produced a dose- and time-dependent inhibition of U-937 cell growth reaching a maximum after 48-h treatment with 500 microM. At this concentration, dBcAMP had no effect on cell viability. Treatment with dBcAMP caused a rapid (within 24 h) decrease in the number of cells in the S phase of the cell cycle, with a concomitant increase in cells in the G0/G1 phase. dBcAMP also induced the appearance of f-met-leu-phe receptors on U-937 cells as well as the ability to produce hydrogen peroxide and superoxide anion. These data suggest that dBcAMP-treated U-937 cells were functionally mature. Using specific monoclonal antibodies and flow cytometry, we found that differentiated U-937 cells expressed the monocytic/granulocytic surface markers MY8 and MAC-1, but not the monocyte specific markers MO2 or MY4. In addition, dBcAMP-treated U-937 cells did not stain for nonspecific esterase, displayed less HLA-DR antibody binding than undifferentiated cells and appeared smaller and more granular. These are all characteristics of mature granulocytes. Taken together our studies indicate that differentiation of U-937 cells is not necessarily limited to the monocytic pathway of development.
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Bucladesina/farmacología , Diferenciación Celular/efectos de los fármacos , Linfoma de Células B Grandes Difuso/patología , Neutrófilos/citología , Células Tumorales Cultivadas/citología , Anticuerpos Monoclonales , Antígenos de Superficie/análisis , Biomarcadores/análisis , Ciclo Celular/efectos de los fármacos , División Celular/efectos de los fármacos , Línea Celular , Técnica del Anticuerpo Fluorescente , Humanos , Peróxido de Hidrógeno/metabolismo , Cinética , N-Formilmetionina Leucil-Fenilalanina/farmacología , Receptores de Formil Péptido , Receptores Inmunológicos/metabolismo , Superóxidos/metabolismo , Células Tumorales Cultivadas/efectos de los fármacosRESUMEN
The ability of murine epidermal cells to produce intracellular hydrogen peroxide was analyzed by flow cytometry and the measurement of 2',7'- dichlorofluorescin (DCFH) oxidation. Epidermal cells isolated from acetone-treated CD-1 mice for 24 h were relatively homogeneous in cell size and density and oxidized low levels of DCFH. However, following 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment of mice (10 micrograms; 24 h), two cytokeratin-positive populations of cells were identified that were heterogeneous with respect to size and density. These two TPA-derived cell populations oxidized levels of DCFH that were time and dose dependent and were between 2- and 10-fold higher than levels of DCFH oxidized by cells isolated from acetone-treated mice. The ability of catalase, the enzyme that detoxifies hydrogen peroxide, to suppress DCFH oxidation to control levels suggested that intracellular hydrogen peroxide was responsible for the enhanced rate of DCFH oxidation in epidermal cells isolated from TPA-treated mice. The ability of mouse epidermal keratinocytes to oxidize DCFH in response to TPA treatment was confirmed using a cloned keratinocyte cell line. These results suggest that specific subpopulations of keratinocytes produce elevated levels of intracellular peroxides following treatment with TPA either in vivo or in culture.
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Peróxido de Hidrógeno/metabolismo , Queratinocitos/efectos de los fármacos , Acetato de Tetradecanoilforbol/farmacología , Animales , Femenino , Citometría de Flujo , Fluoresceínas/metabolismo , Queratinocitos/metabolismo , Queratinocitos/patología , Ratones , Oxidación-Reducción , Oxígeno/metabolismoRESUMEN
The search for surgical prosthetics that do not act to promote infection has been frustrating. However, recent experience with the implantation of polyglycolic acid mesh (PGA) used as an intestinal sling has been associated with a lack of pelvic infections. To examine the basis for these observations, 1 x 1-cm pieces of biomaterials were sewn onto the peritoneal cavity of rats. The biomaterials examined included PGA mesh, a composite mesh composed of a permanent nonabsorbable Novafil inner layer coated with a PGA outer layer, polyvinyl alcohol sponge, and silicon elastomer. Biomaterials were removed at postoperative days 1, 2, 8, and 14, and examined for bacteriostatic and bactericidal activity by standard techniques. Mesh adherent leukocytes were evaluated for their ability to oxidize dichlorofluorescein diacetate (DCFH-DA), which is fluorescent in the presence of intracellular hydrogen peroxide produced by both polymorphonuclear cells and monocytes. PGA and the composite mesh had no intrinsic bacteriostatic or bactericidal activity. However, adherent leukocytes were induced to oxidize DCFH at levels 10-fold and 5-fold, respectively, by postoperative day 14, compared with earlier time points and other biomaterials. The ability of these PGA meshes to stimulate respiratory bursts by peritoneal cells may partly be responsible for the lack of infections associated with their use.
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Materiales Biocompatibles , Leucocitos/fisiología , Cavidad Peritoneal/cirugía , Mallas Quirúrgicas , Animales , Fluoresceínas/metabolismo , Peróxido de Hidrógeno/metabolismo , Leucocitos/metabolismo , Oxidación-Reducción , Poliésteres , Ácido Poliglicólico , Alcohol Polivinílico , Ratas , Elastómeros de SiliconaRESUMEN
The superior larval competitive ability of Aedes albopictus has been proposed to explain the recent displacement of Aedes aegyptiby the former species inparts of the southeastern U.S. Ae. aegypti persists, however, in sympatry with Ae. albopictus in urban areas of southern Louisiana, Florida, and Texas, and the impact of larval competition between these species has not been investigated at higher temperatures that may be characteristic of these urban environments. We compared growth and survivorship of the two species at controlled temperatures of 24 degrees and 30 degrees C in water-containing tires under conditions of intra- and interspecific competition and with or without leaf litter. When other variables were controlled statistically, the estimated finite rate of increase (lambda') was significantly higher for both species at the higher temperature, and the proportional increases in lambda' did not differ between species. Therefore, our experiment predicts that by itself, temperatures between 24 degrees and 30 degrees C would not alter the outcome of larval competition. Overall, response measures of Ae. albopictus were more sensitive than those of Ae. aegypti to the litter and species/density variables, although the development ofAe. aegypti females was uniquely retarded by a high density of its own species.
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Adaptación Fisiológica , Aedes , Temperatura , Animales , Larva/crecimiento & desarrollo , Hojas de la Planta , Dinámica Poblacional , Sobrevida , AguaRESUMEN
BACKGROUND: The healing potential of platelet growth factors has generated interest in using Platelet-Rich Plasma (PRP) in ridge preservation procedures. A canine study was performed to determine if extraction sites treated with platelet-rich fibrin matrix (PRFM) exhibit enhanced healing compared to sites treated with non-viable materials. METHODS: Four dog's extraction sockets were treated individually with PRFM, PRFM and membrane, Demineralized Freeze-Dried Bone Allograft (DFDBA) and membrane, PRFM and DFDBA, and untreated control. Treatment sequencing permitted clinical and histologic evaluation of healing at 10 days, 2, 3, 6 and 12 weeks. RESULTS: Healing was more rapid in the PRFM and PRFM and membrane sites. By 3 weeks those sockets had osseous fill. Sites containing DFDBA had little new bone at 6 weeks. By 12 weeks those sockets had osseous fill but DFDBA particles were still noted in coronal areas. CONCLUSIONS: PRFM alone may be the best graft for ridge preservation procedures. ADVANTAGES: faster healing, and elimination of disadvantages involved in using barrier membranes.
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1. Ca2+ homeostasis in freshly dissociated neurons from embryonic rat hypothalamus, cortex, and brain stem was investigated with flow cytometry. Cells were dissociated from embryonic brain by enzymatic and mechanical means and were incubated with the acetoxymethylester derivative of the Ca(2+)-sensitive dye indo-1. Neurons hydrolyzed and retained the dye as determined by the intensity of fluorescence emission, whereas similarly treated cultured astrocytes gave very low-level fluorescence. 2. The fluorescence of the indo-1 dye was measured at two wavelengths (405 and 485 nm) for each cell. Data were collected only from those cells (presumptive neurons) with high levels of fluorescence. Methods were developed to calibrate the level of intracellular free calcium ([Ca2+]i) as the ratio of fluorescence at 410 and 485 nm. The level of intracellular free Ca2+ was then calculated for each neuron. 3. A wide distribution of resting [Ca2+]i was found, with a median of approximately 90 nM. After addition of ionomycin to cells in Ca(2+)-free medium, there was a transient increase in [Ca2+]i, suggesting that all embryonic neurons had internal Ca2+ stores. The presence of active calcium extrusion mechanisms was demonstrated with the use of ionomycin in Ca(2+)-containing medium and with metabolic inhibitors. Furthermore, incubation in sodium-free medium resulted in a transient increase in [Ca2+]i and a reduced ability to eliminate elevated [Ca2+]i from the cytoplasm, suggesting that calcium homeostasis was dependent on the activity of the Na(+)-Ca2+ exchange mechanism. 4. Depolarization with K+ or veratrine increased [Ca2+]i in approximately 20% of the cells. This increase was blocked by eliminating extracellular free Ca2+ or adding Co2+, nifedipine, or verapamil, suggesting mediation by voltage-sensitive calcium channels. 5. Neurons were sorted on the basis of high [Ca2+]i and placed into dissociated culture. After 24 h, neurons in culture retained indo-1 fluorescence, suggesting that populations of neurons can be collected on the basis of their levels of [Ca2+]i. 6. These results demonstrate that flow cytometric analysis allows the characterization of a variety of Ca(2+)-regulatory mechanisms in populations of freshly dissociated embryonic neurons. Although only a proportion of embryonic day 17 neurons exhibit voltage-sensitive calcium channels, all neurons have developed the ability to sequester and extrude Ca2+.
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Encéfalo/citología , Calcio/fisiología , Homeostasis/fisiología , Neuronas/fisiología , Animales , Encéfalo/embriología , Bloqueadores de los Canales de Calcio/farmacología , Canales de Calcio/metabolismo , Canales de Calcio/fisiología , Células Cultivadas , Ácido Egtácico/farmacología , Femenino , Citometría de Flujo , Indoles , Ionomicina/farmacología , Potasio/farmacología , Embarazo , Ratas , Ratas Endogámicas , Veratrina/farmacologíaRESUMEN
The intestinal sling procedure has been used successfully without the observance of pelvic infections. This procedure involves the implantation of polyglycolic acid (PGA) mesh to hold the bowel out of the pelvis to prevent radiation enteritis. We previously showed that PGA mesh has no intrinsic bactericidal activity. Since phagocytic leukocytes produce reactive oxygen intermediates during respiratory burst that are associated with oxygen-dependent bactericidal activity, we examined peritoneal cell types and their respiratory burst activity isolated from patients with biopsy-confirmed rectal carcinoma who underwent the intestinal sling procedure (N = 12) compared with patients who did not (N = 13). There was no significant difference in the cell types within the peritoneal cavity over the 7-day postoperative period examined. However, there was a significant increase in the ability of leukocytes isolated from mesh patients to produce hydrogen peroxide in the absence of an exogenous stimulus (P less than 0.05), as measured by flow cytometric quantitation of oxidation of the hydroperoxide-sensitive dye, 2',7'-dichlorofluorescin diacetate (DCFH-DA). Despite the higher endogenous DCFH oxidation by leukocytes from mesh patients, the cells retained the ability to oxidize DCFH following treatment with a membrane-active stimulant for respiratory burst activity, 12-O-tetradecanoyl-phorbol-13-acetate. These observations suggest that PGA mesh used for the intestinal sling procedure stimulates the respiratory burst activity of peritoneal leukocytes during the postoperative period in which bacterial proliferation and colonization occur. The stimulation of reactive oxygen intermediates involved in oxygen-dependent bactericidal activity by PGA mesh may be one of the mechanisms underlying the lack of infections observed with the use of PGA mesh in contaminated settings.