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1.
Semin Fetal Neonatal Med ; 28(3): 101444, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37150640

RESUMEN

Severe intracranial hemorrhages are not rare in extremely preterm infants. They occur early, generally when babies require life-sustaining interventions. This may lead to ethical discussions and decision-making about levels of care. Prognosis is variable and depends on the extent, location, and laterality of the lesions, and, importantly also on the subsequent occurrence of other clinical complications or progressive ventricular dilatation. Decision-making should depend on prognosis and parental values. This article will review prognosis and the uncertainty of outcomes for different lesions and provide an outline of ways to conduct an ethically appropriate discussion on the decision of whether to continue life sustaining therapy. It is possible to communicate in a compassionate and honest way with parents and engage in decision-making, focussing on personalized information and decisions, and on function, as opposed to diagnosis.


Asunto(s)
Recien Nacido Extremadamente Prematuro , Privación de Tratamiento , Humanos , Recién Nacido , Padres , Comunicación , Hemorragia , Toma de Decisiones
2.
J Crohns Colitis ; 16(2): 216-223, 2022 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-34379117

RESUMEN

BACKGROUND: Canadian-born children of South Asian [SA] ethnicity develop inflammatory bowel disease [IBD] at similar rates to those among Caucasian children. We evaluated the variation in phenotypic spectrum of IBD in SA and Caucasian children in a national paediatric inception cohort of new-onset IBD. METHODS: Patients aged <17 years, enrolled in a Canadian nationwide inception cohort study, were included. Baseline demographic and IBD phenotypic features were compared between SA and Caucasian children. Longitudinal outcomes through 18 months of follow-up were compared matched by propensity scores. RESULTS: Of 1156 children enrolled over 2014 to 2019, 623 were Caucasian [98% and 88% parents Canadian born] and 114 SA [79% Canadian born, 87% parents SA born]. Fewer SAs have a first-degree relative with IBD, 6% vs 19% in Caucasians, p = 0.002. SAs present at a younger age, median age 11.4 years (interquartile range [IQR] 9.2-14.3) vs 13 years [IQR 10.9-15 years], p = 0.03 and more commonly with a UC/IBD-U [ulcerative colitis/IBD-unclassified] subtype [ratio of UC/IBD-U to CD 1.2:1 vs 1:1.8 for Caucasians, p <0.001]. Additionally, a greater proportion of SA CD patients present with colonic-only disease [colonic-only CD/UC/IBD-U in SAs 67% vs 57% for Caucasians, p = 0.001], and among those with CD, colonic CD in SAs 31% vs 23% in Caucasians, p = 0.20]. Perianal fistulising disease was also numerically more common in SAs (14 [27%] vs 64 [18%], p = 0.06]. Adjusting for differences in phenotypic presentation, anti-tumour necrosis factor [TNF] exposure, and time to initiation was similar, and two-thirds of children, whether anti-TNF exposed or naïve, were in corticosteroid-free clinical remission at 18 months irrespective of ethnicity. CONCLUSIONS: The phenotypic spectrum of new-onset IBD in SA children differs from that of Caucasian children, but treatment and clinical course are similar within phenotypic subgroups.


Asunto(s)
Colitis Ulcerosa , Enfermedad de Crohn , Enfermedades Inflamatorias del Intestino , Adolescente , Canadá/epidemiología , Niño , Estudios de Cohortes , Colitis Ulcerosa/terapia , Enfermedad de Crohn/terapia , Etnicidad , Humanos , Estudios Prospectivos , Inhibidores del Factor de Necrosis Tumoral
3.
J. obstet. gynaecol. Can ; 43(1): 124-139, Jan. 1, 2021.
Artículo en Inglés | BIGG - guías GRADE | ID: biblio-1146592

RESUMEN

This revised guideline is intended to provide an update on the genetic aspects, prevention, screening, diagnosis, and management of fetal neural tube defects. Target population: Women who are pregnant or may become pregnant. Neural tube defect screening should be offered to all pregnant women. For prevention: a folate-rich diet, and folic acid and vitamin B12 supplementation, with dosage depending on risk level. For screening: second-trimester anatomical sonography; first-trimester sonographic screening; maternal serum alpha fetoprotein; prenatal magnetic resonance imaging. For genetic testing: diagnostic amniocentesis with chromosomal microarray and amniotic fluid alpha fetoprotein and acetylcholinesterase; fetal exome sequencing. For pregnancy management: prenatal surgical repair; postnatal surgical repair; pregnancy termination with autopsy. For subsequent pregnancies: prevention and screening options and counselling. The research on and implementation of fetal surgery for prenatally diagnosed myelomeningocele has added a significant treatment option to the previous options (postnatal repair or pregnancy termination), but this new option carries an increased risk of maternal morbidity. Significant improvements in health and quality of life, both for the mother and the infant, have been shown to result from the prevention, screening, diagnosis, and treatment of fetal neural tube defects. The benefits for patient autonomy and decision-making are provided in the guideline. Harms include an unexpected fetal diagnosis and the subsequent management decisions. Harm can also result if the patient declines routine sonographic scans or if counselling and access to care for neural tube defects are delayed. Cost analysis (personal, family, health care) is not within the scope of this clinical practice guideline. A directed and focused literature review was conducted using the search terms spina bifida, neural tube defect, myelomeningocele, prenatal diagnosis, fetal surgery, neural tube defect prevention, neural tube defect screening, neural tube defect diagnosis, and neural tube defect management in order to update and revise this guideline. A peer review process was used for content validation and clarity, with appropriate ethical considerations. The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations). Maternity care professionals who provide any part of pre-conception, antenatal, delivery, and neonatal care. This guideline is also appropriate for patient education.


Asunto(s)
Humanos , Femenino , Embarazo , Complicaciones del Embarazo/prevención & control , Manejo de Atención al Paciente/organización & administración , Desarrollo Fetal/genética , Defectos del Tubo Neural/prevención & control , Adenina/uso terapéutico , Ultrasonografía Prenatal/métodos , Ácido Fólico/uso terapéutico
4.
J Crohns Colitis ; 14(4): 445-454, 2020 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-31136648

RESUMEN

BACKGROUND AND AIMS: Incidence of paediatric inflammatory bowel disease [IBD] in Canada is among the highest worldwide, and age of onset may be decreasing. In a multicentre nationwide inception cohort study, we examined variation in phenotype of IBD throughout the paediatric age spectrum. METHODS: Children aged ≥2 years [y] and <17y [A1 age at diagnosis], with new onset IBD, were systematically evaluated at sites of the Canadian Children IBD Network. Prospectively recorded phenotypic data were compared between age groups. RESULTS: Among 1092 children (70% Caucasian; 64% Crohn's disease [CD], 36% ulcerative colitis/inflammatory bowel disease unclassified [UC/IBD-U]; median age 13 y, interquartile range [IQR] 11-15 y), 210 [19%] were diagnosed before the age of age 10 y [Paris A1a] and 43 [4%] before age 6 y (very-early-onset [VEO-IBD]). CD was less common in younger children [42%, 56%, 66%, respectively, of VEO-IBD, A1a; A1b]. Colon-only IBD [UC/IBDU or CD-colon] was present in 81% of VEO-IBD and 65% of A1a; ileal disease increased progressively, reaching plateau at age 10 y. CD location was ileocolonic [L3] in 53% overall. Ileitis [L1] increased with age [6% of VEO-IBD; 13% of A1a; 21% of A1b], as did stricturing/penetrating CD [4% of A1a; 11% of A1b]. At all ages UC was extensive [E3/E4] in >85%, and disease activity moderate to severe according to Physician's Global Assessment [PGA] and weighted Paediatric Crohn's Disease Activity Index/Paediatric Ulcerative Colitis Activity Index [wPCDAI/PUCAI] in >70%. Heights were modestly reduced in CD [mean height z score -0.30 ± 1.23], but normal in UC/IBD-U. CONCLUSIONS: Paris classification of age at diagnosis is supported by age-related increases in ileal disease until age 10 years. Other phenotypic features, including severity, are similar across all ages. Linear growth is less impaired in CD than in historical cohorts, reflecting earlier diagnosis.


Asunto(s)
Colitis Ulcerosa , Enfermedad de Crohn , Edad de Inicio , Variación Biológica Poblacional , Canadá/epidemiología , Niño , Estudios de Cohortes , Colitis Ulcerosa/diagnóstico , Colitis Ulcerosa/epidemiología , Colitis Ulcerosa/fisiopatología , Enfermedad de Crohn/diagnóstico , Enfermedad de Crohn/epidemiología , Enfermedad de Crohn/fisiopatología , Progresión de la Enfermedad , Femenino , Humanos , Incidencia , Masculino , Estudios Prospectivos , Índice de Severidad de la Enfermedad
5.
Child Care Health Dev ; 43(6): 783-796, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28370174

RESUMEN

BACKGROUND: Parents undergo multiple transitions following the birth of an ill infant: their infant's illness-health trajectory, neonatal intensive care unit hospitalization and transfers from one healthcare setting to another, while also transitioning to parenthood. The objective of this review was to map and synthesize evidence on the experiences and needs of parents of preterm or ill infants as they transition within and between healthcare settings following birth. METHODS: The scoping review followed Arskey and O'Malley's () framework, enhanced by Levac et al. (). Relevant studies were identified through a comprehensive search strategy of scientific and grey literature databases, online networks, Web of Science and citation lists of relevant articles. Inclusion criteria encompassed a focus on infants undergoing a healthcare transition, and the experiences and needs of parents during transition. Studies were appraised for design quality, and data relevant to parent experiences were extracted and underwent thematic analysis. RESULTS: A total of 7773 records were retrieved, 90 full texts reviewed and 11 articles synthesized that represented a total sample of 435 parents of preterm or ill infants. Parents reported on their experiences in response to their infant's transition within and between hospitals and across levels of neonatal intensive care unit, intermediate and community hospital care. Ten studies used qualitative research methods, while one employed quantitative survey methods. Four key themes were identified: that of parent distress throughout transition, parenting at a distance, sources of stress and sources of support. Parents' stress resulted from not being informed or involved in the transition decision, inadequate communication and perceived differences in cultures of care across healthcare settings. CONCLUSIONS: Opportunities to improve parents' early transition experiences include enhanced engagement, communication, information-sharing and shared decision-making between health care providers and parents. Future areas of research should focus on early transition interventions to advance parent capacity, confidence and closeness as the primary nurturer.


Asunto(s)
Actitud Frente a la Salud , Servicios de Salud del Niño/organización & administración , Padres/psicología , Transferencia de Pacientes/organización & administración , Enfermedad Aguda , Humanos , Lactante , Recién Nacido , Responsabilidad Parental/psicología , Relaciones Profesional-Familia , Investigación Cualitativa
6.
Child Care Health Dev ; 41(6): 954-62, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26010416

RESUMEN

BACKGROUND: Urinary incontinence is frequently experienced by children with spina bifida, putting them at increased risk for low self-esteem and impacting upon participation in home, school and leisure activities. However, little is known about children's experiences of these continence issues. OBJECTIVE: This study explored the experiences of children and young people with spina bifida around continence issues, social participation and peer relationships, in order to identify potential areas of support healthcare professionals can provide. METHODS: Children and youth aged 6-18 years with diagnoses of spina bifida and neurogenic bladder and their parents were invited to participate in semi-structured interviews. Descriptive thematic analysis was employed. RESULTS: Eleven children (with a range of mobility levels, types of spina bifida and degrees of bladder control) and their parents participated in the study. Three broad themes were identified, which encompassed the following: (1) normal versus different; (2) independence, ownership and the road to continence; and (3) peer relationships and acceptance. DISCUSSION: The experiences discussed by the children and parents in this study ranged from minimal impact of incontinence on their day-to-day living to significant social isolation and rejection. The stigma of incontinence was apparent in all interviews. Children and youth who were able to control their bladder with minimal accidents had greater independence and more opportunities for social participation. Healthcare professionals need to take into account that parents and their children may differ in attitudes and desires about the management of incontinence.


Asunto(s)
Actitud Frente a la Salud , Participación Social , Disrafia Espinal/complicaciones , Incontinencia Urinaria/etiología , Incontinencia Urinaria/psicología , Adolescente , Niño , Femenino , Humanos , Relaciones Interpersonales , Masculino , Ontario , Padres/psicología , Grupo Paritario , Investigación Cualitativa , Autocuidado , Disrafia Espinal/psicología , Disrafia Espinal/rehabilitación , Incontinencia Urinaria/rehabilitación
7.
Aliment Pharmacol Ther ; 41(2): 153-66, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25403954

RESUMEN

BACKGROUND: In the treatment of Crohn's disease (CD), mucosal healing has become a major goal, with the hope of avoiding intestinal damage from chronic inflammation. Magnetic resonance enterography (MRE) has emerged as a non-invasive means of monitoring inflammation and damage. AIMS: As part of the development of MRE-based multi-item measures of inflammation and damage for paediatric studies, we carried out a systematic review and meta-analysis to identify MRE variables used to describe these two distinct concepts. METHODS: 2501 studies of MRI and CD were identified. Studies written in any language reporting individual MRE signs for patients diagnosed with CD were included. Two-hundred-and-forty-four studies were fully reviewed and 62 were included (inflammation, n = 51; damage, n = 24). Sensitivity, specificity and associated confidence intervals were calculated, and hierarchical summary ROC curves were constructed for each MRE sign. RESULTS: A total of 22 MRE signs were used to reflect inflammation, and 9 to reflect damage. Diagnostic accuracy of MRE signs of inflammation and damage was heterogeneous; however, wall enhancement, mucosal lesions and wall T2 hyperintensity were the most consistently useful for inflammation (most sensitivities >80% and specificities >90%), and detection of abscess and fistula were most consistently useful for damage (most sensitivities >90%, specificities >95%). CONCLUSIONS: Identifying the best MRE variables to reflect inflammation and damage will maximise the utility of this rapidly emerging technique and is the first stage of constructing MRE-based indices for evaluating inflammation and intestinal damage.


Asunto(s)
Absceso Abdominal/diagnóstico , Enfermedad de Crohn/diagnóstico , Inflamación/diagnóstico , Fístula Intestinal/diagnóstico , Imagen por Resonancia Magnética , Absceso Abdominal/complicaciones , Niño , Enfermedad de Crohn/complicaciones , Humanos , Inflamación/complicaciones , Fístula Intestinal/complicaciones , Curva ROC , Sensibilidad y Especificidad , Evaluación de Síntomas
8.
Ann N Y Acad Sci ; 976: 356-66, 2002 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12502582

RESUMEN

Immunocytochemistry reveals that the Na/Ca exchanger (NCX) in neuronal somata and astrocytes is confined to plasma membrane (PM) microdomains that overlie sub-PM (junctional) endoplasmic reticulum (jER). By contrast, the PM Ca(2+) pump (PMCA) is more uniformly distributed in the PM. At presynaptic nerve terminals, the NCX distribution is consistent with that observed in the neuronal somata, but the PMCA is clustered at the active zones. Thus, the PMCA, with high affinity for Ca(2+) (K(d) congruent with 100 nM), may keep active zone Ca(2+) very low and thereby "reprime" the vesicular release mechanism following activity. NCX, with lower affinity for Ca(2+) (K(d) congruent with 1,000 nM), on the other hand, may extrude Ca(2+) that has diffused away from the active zones and been temporarily sequestered in the endoplasmic reticulum. The PL microdomains that contain the NCX also contain Na(+) pump high ouabain affinity alpha2 (astrocytes) or alpha 3 (neurons) subunit isoforms (IC(50) congruent with 5-50 nM ouabain). In contrast, the alpha1 isoform (low ouabain affinity in rodents; IC(50) >10,000 nM), like the PMCA, is more uniformly distributed in these cells. The sub-PM endoplasmic reticulum in neurons (and probably glia and other cell types as well) and the adjacent PM form junctions that resemble cardiac muscle dyads. We suggest that the PM microdomains containing NCX and alpha 2/alpha 3 Na(+) pumps, the underlying jER, and the intervening tiny volume of cytosol (<10(-18) l) form functional units (PLasmERosomes); diffusion of Na(+) and Ca(2+) between these cytosolic compartments and "bulk" cytosol may be markedly restricted. The activity of the Na(+) pumps with alpha 2/alpha 3 subunits may thus regulate NCX activity and jER Ca(2+) content. This view is supported by studies in mice with genetically reduced (by congruent with 50%) alpha 2 Na(+) pumps: evoked Ca(2+) transients were augmented in these cells despite normal cytosolic Na(+) and resting Ca(2+) concentrations ([Na(+)](CYT) and [Ca(2+)](CYT)). We conclude that alpha 2/alpha 3 Na(+) pumps control PLasmERosome (local) [Na(+)](CYT). This, in turn, via NCX, modulates local [Ca(2+)](CYT), jER Ca(2+) storage, Ca(2+) signaling, and cell responses.


Asunto(s)
Astrocitos/metabolismo , ATPasas Transportadoras de Calcio/metabolismo , Membrana Celular/metabolismo , Neuronas/metabolismo , Intercambiador de Sodio-Calcio/metabolismo , Animales , Encéfalo/metabolismo , Isoenzimas/metabolismo , Cinética , Ratones , Modelos Biológicos , Subunidades de Proteína/metabolismo
9.
J Neurosci ; 21(3): RC127, 2001 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-11157098

RESUMEN

In the present study, we examined the targeting of neuropeptide-containing vesicles in terminals of neurons that release both neuropeptides and classical transmitters. Single neurons were electrically stimulated with patterns of activity that were recorded in freely behaving animals. The amount of peptide release was measured biochemically using a radioimmunoassay, and the targeting of peptidergic vesicles was quantified using immunoelectronmicroscopy. Repeated electrical stimulation of single neurons produced a very large increase in peptide release. Peptide release is paralleled by a twofold increase in the number of peptidergic vesicles docked at the portion of the terminal membrane that is away from the target muscle. This is in stark contrast to cholinergic vesicles, which aggregate at, and are released from the conventional release sites in close apposition to the muscle. This differential targeting of cholinergic and peptidergic vesicles may play a significant role in the distinct release requirements and spatial and temporal characteristics of the actions of conventional and peptidergic transmitters.


Asunto(s)
Terminales Presinápticos/metabolismo , Transmisión Sináptica/fisiología , Vesículas Sinápticas/metabolismo , Animales , Aplysia , Estimulación Eléctrica , Técnicas In Vitro , Microscopía Inmunoelectrónica , Neuronas Motoras/citología , Neuronas Motoras/metabolismo , Unión Neuromuscular/metabolismo , Neuropéptidos/análisis , Neuropéptidos/metabolismo , Neurotransmisores/metabolismo , Terminales Presinápticos/ultraestructura , Radioinmunoensayo , Vesículas Secretoras/metabolismo , Vesículas Secretoras/ultraestructura , Vesículas Sinápticas/ultraestructura
10.
J Neurosci ; 20(18): 6760-72, 2000 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-10995819

RESUMEN

In this paper we construct, on the basis of existing experimental data, a mathematical model of firing-elicited release of peptide transmitters from motor neuron B15 in the accessory radula closer neuromuscular system of Aplysia. The model consists of a slow "mobilizing" reaction and the fast release reaction itself. Experimentally, however, it was possible to measure only the mean, heavily averaged release, lacking fast kinetic information. Considered in the conventional way, the data were insufficient to completely specify the details of the model, in particular the relative properties of the slow and the unobservable fast reaction. We illustrate here, with our model and with additional experiments, how to approach such a problem by considering another dimension of release, namely its pattern dependence. The mean release is sensitive to the temporal pattern of firing, even to pattern on time scales much faster than the time scale on which the release is averaged. The mean release varies with the time scale and magnitude of the pattern, relative to the time scale and nonlinearity of the release reactions with which the pattern interacts. The type and magnitude of pattern dependence, especially when correlated systematically over a range of patterns, can therefore yield information about the properties of the release reactions. Thus, temporal pattern can be used as a probe of the release process, even of its fast, directly unobservable components. More generally, the analysis provides insights into the possible ways in which such pattern dependence, widespread especially in neuropeptide- and hormone-releasing systems, might arise from the properties of the underlying cellular reactions.


Asunto(s)
Modelos Neurológicos , Neuronas Motoras/metabolismo , Neuropéptidos/metabolismo , Dinámicas no Lineales , Animales , Aplysia , Simulación por Computador , Ganglios de Invertebrados/citología , Ganglios de Invertebrados/metabolismo , Técnicas In Vitro , Valor Predictivo de las Pruebas , Tiempo de Reacción/fisiología , Reproducibilidad de los Resultados
11.
Urology ; 56(3): 492-5, 2000 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-10962322

RESUMEN

We describe a procedure for intraoperative treatment planning for seed implantation. One hundred seven treatment plans have been analyzed at the Beth Israel Deaconess Medical Center and affiliated hospitals. The average time for the intraoperative procedure was 1. 74 hours. No significant difference in dose coverage to the prostate or normal tissues was evident.


Asunto(s)
Braquiterapia/métodos , Radioisótopos de Yodo/uso terapéutico , Neoplasias de la Próstata/radioterapia , Humanos , Periodo Intraoperatorio , Masculino , Quirófanos , Neoplasias de la Próstata/cirugía , Dosificación Radioterapéutica
12.
Exp Dermatol ; 9(4): 275-82, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10949550

RESUMEN

Dermatitis herpetiformis (DH) is a blistering skin disease characterized by cutaneous deposits of IgA and an associated, most often asymptomatic, gluten sensitive enteropathy (GSE). Gluten sensitive enteropathy is also seen in patients that do not have skin disease or cutaneous IgA deposits, but do have significant gastrointestinal (GI) complaints. Patients with DH and with GSE without skin disease have similar small bowel morphologic changes and HLA associations and both the skin disease and the GI symptoms can be controlled by a gluten free diet. It is not known what factors allow almost all patients with DH to continue to eat gluten and not develop symptomatic gastrointestinal disease. We have examined the expression of the Vbeta T-cell receptor (TCR) in the small bowel of patients with DH (n=11) and of patients with both symptomatic (n=10) and asymptomatic (n=7) GSE without skin disease to determine if differences in the pattern of TCR Vbeta expression are associated with differences in the clinical manifestations of these diseases. TCR Vbeta expression was analyzed using RT-PCR from small bowel biopsies. Patients with DH and those with GSE without skin disease that were on a gluten free diet and asymptomatic were found to express 6.6 and 5.6 out of 20 Vbeta families respectively, with no single family preference. Examination of peripheral blood lymphocytes from these patients did not reveal any restriction of TCR Vbeta family expression. In contrast, patients with symptomatic GSE expressed 12.6 Vbeta families (P< 0.05), with no consistent preferential expression of any single Vbeta family between patients. Patients with DH, who are continuing to ingest wheat, show a more restricted pattern of TCR Vbeta utilization, similar to that of treated patients with GSE without skin disease, and significantly different from GSE without skin disease patients eating gluten. These findings suggest that the restricted nature of the TCR Vbeta expression may play a role in the different clinical manifestations of dermatitis herpetiformis and isolated gluten sensitive enteropathy.


Asunto(s)
Enfermedad Celíaca/genética , Enfermedad Celíaca/inmunología , Dermatitis Herpetiforme/genética , Dermatitis Herpetiforme/inmunología , Intestino Delgado/inmunología , Receptores de Antígenos de Linfocitos T alfa-beta/genética , Adolescente , Adulto , Anciano , Enfermedad Celíaca/complicaciones , Enfermedad Celíaca/dietoterapia , Dermatitis Herpetiforme/complicaciones , Proteínas en la Dieta/administración & dosificación , Femenino , Expresión Génica , Glútenes/administración & dosificación , Humanos , Masculino , Persona de Mediana Edad
13.
Eur J Neurosci ; 12(3): 839-46, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10762313

RESUMEN

The plasma membrane ATP-driven Ca2+ pump (PMCA) and the Na+/Ca2+ exchanger (NCX) are the major means of Ca2+ extrusion at presynaptic nerve terminals, but little is know about the location of these transporters relative to the major sites of Ca2+ influx, the transmitter release sites. We used immunocytochemistry to identify these transport proteins in a calyx-type presynaptic nerve terminal from the ciliary ganglion of the chick. The PMCA clusters were localized to the transmitter release sites, as identified by staining for the secretory vesicle-specific protein synaptotagmin I. This colocalization was not due to the presence of the pump on the secretory vesicle itself because membrane fractionation of chick brain synaptosomes demonstrated comigration of the pump with surface membrane and not vesicle markers. In contrast, the NCX did not colocalize with synaptotagmin but tended to be located at nonsynaptic regions of the terminal. The PMCA location, near the transmitter release sites, suggests that it plays a role in priming the release site by maintaining a low free Ca2+ level, facilitating the dissociation of the ion from its binding sites. The PMCA may also replenish external Ca2+ in the synaptic cleft following periods of synaptic activity. In contrast, the NCX location suggests a role in the rapid emptying of cytoplasmic Ca2+ uptake organelles which serve as the main line of defence against high free Ca2+.


Asunto(s)
Proteínas de Unión al Calcio , ATPasas Transportadoras de Calcio/metabolismo , Terminales Presinápticos/metabolismo , Intercambiador de Sodio-Calcio/metabolismo , Animales , Western Blotting , Encéfalo/citología , Embrión de Pollo , Ganglios Parasimpáticos/citología , Ganglios Parasimpáticos/metabolismo , Glicoproteínas de Membrana/metabolismo , Microscopía Fluorescente , Terminaciones Nerviosas/enzimología , Terminaciones Nerviosas/metabolismo , Terminaciones Nerviosas/ultraestructura , Proteínas del Tejido Nervioso/metabolismo , Neurotransmisores/metabolismo , Terminales Presinápticos/enzimología , Terminales Presinápticos/ultraestructura , Sinaptosomas/metabolismo , Sinaptotagmina I , Sinaptotagminas
14.
Prostate ; 39(3): 153-8, 1999 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-10334103

RESUMEN

BACKGROUND: Measurement of the free fraction of total prostate-specific antigen (fPSA%) has been proposed as a useful addition to total PSA for the detection of prostate cancer. METHODS: We assessed the performance of fPSA% in differentiating men with prostate cancer from men without cancer in a group of 1,709 subjects studied in five institutions. RESULTS: On the basis of PSA testing, digital rectal examination, and ultrasound examination conducted at one or more visits, 229 cancers were diagnosed. The mean fPSA% in men with cancer was 9.1% compared to 18.9% in men without cancer. The fPSA% varied by age, with men under 60 having a mean fPSA of 13.9% compared to 17.5% in men 60-69 years old and 19.8% in men over age 70. Significant associations of fPSA% with gland volume and PSA level were also observed. The sensitivity, specificity, and positive predictive value of different fPSA% cutoff levels were assessed in 513 men who underwent sextant biopsy. Sensitivity of 85.4%, 32.1% specificity, and a 39.2% positive predictive value were observed using an fPSA cutoff of 15% in men with PSA in the 4.0-9.9 ng/ml range. Sensitivity of 96.9%, 12.3% specificity, and a 36.2% positive predictive value were observed using an fPSA cutoff of 20% in the same men. If 15% fPSA had been used as a biopsy criterion in men with PSA of 4.0-9.9 ng/ml, the number of biopsies performed could have been reduced by 21.2%, with a concomitant reduction in cancer detection of 14.6%. Using a 20% fPSA criterion, biopsies would have been reduced 12.7%, with a 3.1% reduction in cancer detection. CONCLUSIONS: These results provide some evidence that the detection of prostate cancer is enhanced by measuring fPSA% in addition to the established measure of total PSA level. Further research is needed to identify other markers that have better sensitivity and specificity.


Asunto(s)
Antígeno Prostático Específico/metabolismo , Neoplasias de la Próstata/diagnóstico , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Humanos , Masculino , Persona de Mediana Edad , Próstata/fisiopatología , Neoplasias de la Próstata/metabolismo , Sensibilidad y Especificidad
15.
J Urol ; 156(4): 1280-5, 1996 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8808854

RESUMEN

PURPOSE: The purpose of this trial was to evaluate an immunoassay for urinary nuclear matrix protein, NMP22, as an indicator for transitional cell carcinoma of the urinary tract. MATERIALS AND METHODS: Three groups of subjects participated in this trial of NMP22: 1-175 with transitional cell carcinoma, 2-117 with benign urinary tract conditions and 3-375 healthy volunteers. Each subject provided a single (3 voids) urine sample for analysis at the time of study entry. Each sample was assayed for the level of NMP22. RESULTS: In normal healthy volunteers and in subjects with benign conditions median NMP22 levels were 2.9 and 3.3 units per ml., respectively. Median urinary NMP22 levels in patients with transitional cell carcinoma were significantly greater than in comparison subjects. Patients with active transitional cell carcinoma had significantly greater median urinary NMP22 levels than those with no evidence of disease (6.04 versus 4.11 units per ml., p = 0.027, 1-tailed Mann-Whitney U test). We noted no effect of tumor grade, extent of disease or exposure to intravesical therapy on urinary NMP22 levels. CONCLUSIONS: NMP22 is a promising urinary tumor marker for monitoring transitional cell carcinoma. Nuclear matrix proteins are a new class of tumor markers that represent the basis for the development of assays with increased efficacy for the detection and treatment of cancer.


Asunto(s)
Biomarcadores de Tumor/orina , Carcinoma de Células Transicionales/orina , Proteínas Nucleares/orina , Neoplasias Urológicas/orina , Anciano , Anciano de 80 o más Años , Carcinoma de Células Transicionales/patología , Carcinoma de Células Transicionales/terapia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Neoplasias Urológicas/patología , Neoplasias Urológicas/terapia
16.
J Physiol ; 496 ( Pt 1): 59-68, 1996 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-8910196

RESUMEN

1. Single L-type calcium channels in chick ciliary ganglion neurons were studied at high current resolution in cell-attached patch recordings using quartz-glass micropipettes. 2. A single open-channel current amplitude was observed when Ba2+ was the charge carrier with a conductance of 26 pS at 110 mM barium. However, with 110 mM calcium two current fluctuation amplitudes were observed. These were termed low and high fluctuation amplitudes, CaL and CaH, and had conductances of 8.8 and 12 pS, respectively. These two levels probably reflect two different channel species. CaL was identified as an L-type calcium channel on the basis of resistance to inactivation, conductance, and dihydropyridine sensitivity. 3. Single-channel current fluctuations could be detected with calcium concentrations as low as 1.0 mM. Although the unitary conductance (gamma) was much greater with barium than calcium at every concentration tested, the concentration dependence of conductance was similar for gamma Ba, gamma CaH and gamma CaL. Fitting the concentration dependencies of these conductances with a Langmuir isotherm gave KD estimates of 4.7, 5.6 and 5.0 mM for barium, CaL and CaH, respectively 4. The single-channel conductance of the L-type channel (gamma L) can be described by the relation: conductance (in pS) = 9.2/(1 + 5.6/[Ca]) where [Ca] is the external calcium concentration in the 1.0-110 mM range. Thus, at a physiological external calcium concentration of 2 mM the conductance is 2.4 pS. 5. Ca2+ transport through the L-type calcium channel is particularly sensitive to changes in external calcium concentration in the physiological range but approaches saturation at about 10 mM. this characteristic may optimize the responsiveness of the cell to small changes in ambient calcium concentrations while limiting excess entry in the presence of abnormally high calcium levels.


Asunto(s)
Canales de Calcio/metabolismo , Calcio/metabolismo , Ganglios Parasimpáticos/metabolismo , Ácido 3-piridinacarboxílico, 1,4-dihidro-2,6-dimetil-5-nitro-4-(2-(trifluorometil)fenil)-, Éster Metílico/farmacología , Animales , Bario/farmacología , Agonistas de los Canales de Calcio/farmacología , Bloqueadores de los Canales de Calcio/farmacología , Canales de Calcio/efectos de los fármacos , Embrión de Pollo , Electrofisiología , Ganglios Parasimpáticos/efectos de los fármacos , Activación del Canal Iónico/efectos de los fármacos , Técnicas de Placa-Clamp , Termodinámica
17.
Infect Immun ; 64(9): 3833-44, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8751936

RESUMEN

The highly attenuated NYVAC vaccinia virus strain has been utilized to develop a multiantigen, multistage vaccine candidate for malaria, a disease that remains a serious global health problem and for which no highly effective vaccine exists. Genes encoding seven Plasmodium falciparum antigens derived from the sporozoite (circumsporozoite protein and sporozoite surface protein 2), liver (liver stage antigen 1), blood (merozoite surface protein 1, serine repeat antigen, and apical membrane antigen 1), and sexual (25-kDa sexual-stage antigen) stages of the parasite life cycle were inserted into a single NYVAC genome to generate NYVAC-Pf7. Each of the seven antigens was expressed in NYVAC-Pf7-infected culture cells, and the genotypic and phenotypic stability of the recombinant virus was demonstrated. When inoculated into rhesus monkeys, NYVAC-Pf7 was safe and well tolerated. Antibodies that recognize sporozoites, liver, blood, and sexual stages of P. falciparum were elicited. Specific antibody responses against four of the P.falciparum antigens (circumsporozoite protein, sporozoite surface protein 2, merozoite surface protein 1, and 25-kDa sexual-stage antigen) were characterized. The results demonstrate that NYVAC-Pf7 is an appropriate candidate vaccine for further evaluation in human clinical trials.


Asunto(s)
Anticuerpos Antiprotozoarios/inmunología , Antígenos de Protozoos/genética , Vacunas contra la Malaria/genética , Malaria Falciparum/prevención & control , Plasmodium falciparum/inmunología , Vacunas Sintéticas/genética , Secuencia de Aminoácidos , Animales , Antígenos de Superficie/genética , Secuencia de Bases , Cartilla de ADN/química , Genes Protozoarios , Vectores Genéticos , Células HeLa , Humanos , Macaca mulatta , Malaria Falciparum/inmunología , Datos de Secuencia Molecular , Proteínas Protozoarias/genética , Virus Vaccinia
18.
J Urol ; 156(2 Pt 1): 363-7, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8683680

RESUMEN

PURPOSE: We evaluated the ability of an immunoassay for nuclear matrix protein 22 (NMP22 test kit) to predict the subsequent disease status of patients with transitional cell carcinoma of the urinary tract at approximately 10 days after transurethral resection of bladder tumor. MATERIALS AND METHODS: A total of 90 patients with transitional cell carcinoma provided voided urine samples at least 5 days postoperatively. NMP22 was determined using a commercial test kit. At initial cystoscopic examination 3 to 6 months later the disease status was recorded, and the NMP22 values before and after transurethral resection of bladder tumor were compared. RESULTS: Of 125 followup cystoscopic examinations (60 patients had 1, 26 had 2, 3 had 3 and 1 had 4 recurrences) transitional cell carcinoma was pathologically confirmed in 33. No malignancy was present at 79 examinations (if tumor was seen endoscopically, pathological evaluation indicated atypia, dysplasia or no abnormality). NMP22 values in these 2 populations were significantly different (malignancy median 20.81 units per ml. and no malignancy median 5.72 units per ml., Mann-Whitney U test for differences between 2 medians p = 0.00005). Of the 33 recurrences 23 (70%) had NMP22 values greater than the reference range (10 units per ml.). Additionally, NMP22 identified all 6 subjects (100%) who had invasive disease 3 to 6 months later. Of 72 patients with NMP22 less than 10 units per ml. 62 (86%) had no malignancy at subsequent cystoscopy. CONCLUSIONS: NMP22 was highly predictive of tumor status at followup cystoscopy. This quantitative, noninvasive assay, with high negative predictive value (86%) and sensitivity to detect malignancy (100% for invasive disease and 70% overall), may be a helpful adjunct to cytology and endoscopy for monitoring disease status after endoscopic tumor resection.


Asunto(s)
Biomarcadores de Tumor/orina , Carcinoma de Células Transicionales/diagnóstico , Recurrencia Local de Neoplasia/diagnóstico , Proteínas Nucleares/orina , Neoplasias de la Vejiga Urinaria/diagnóstico , Carcinoma de Células Transicionales/cirugía , Carcinoma de Células Transicionales/orina , Intervalos de Confianza , Cistoscopía , Estudios de Seguimiento , Humanos , Recurrencia Local de Neoplasia/orina , Valor Predictivo de las Pruebas , Curva ROC , Juego de Reactivos para Diagnóstico , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Factores de Tiempo , Neoplasias de la Vejiga Urinaria/cirugía , Neoplasias de la Vejiga Urinaria/orina
19.
Mol Immunol ; 32(17-18): 1301-9, 1995 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8643099

RESUMEN

We investigated the immunogenicity and the conformational properties of the non-repetitive sequences of the Plasmodium falciparum circumsporozoite (CS) protein. Two polypeptides of 104 and 102 amino acids long, covering, respectively, the N- and C-terminal regions of the CS protein, were synthesized using solid phase Fmoc chemistry. The crude polypeptides were purified by a combination of size exclusion chromatography and RP-HPLC. Sera of mice immunized with the free polypeptides emulsified in incomplete Freund's adjuvant strongly reacted with the synthetic polypeptides as well as with native CS protein as judged by ELISA and IFAT assays. Most importantly, these antisera inhibited the sporozoite invasion of hepatoma cells. In addition, sera derived from donors living in a malaria endemic area recognized the CS 104- and 102-mers. Conformational studies of the CS polypeptides were also performed by circular dichroism spectroscopy showing the presence of a weakly ordered structure that can be increased by addition of trifluoroethanol. The obtained results indicate that the synthetic CS polypeptides and the natural CS protein share some common antigenic determinants and probably have similar conformation. The approach used in this study might be useful for the development of a synthetic malaria vaccine.


Asunto(s)
Péptidos/química , Péptidos/síntesis química , Plasmodium falciparum/química , Plasmodium falciparum/inmunología , Proteínas Protozoarias/química , Proteínas Protozoarias/síntesis química , Secuencia de Aminoácidos , Aminoácidos/síntesis química , Aminoácidos/química , Aminoácidos/inmunología , Animales , Reacciones Antígeno-Anticuerpo , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Péptidos/inmunología , Conformación Proteica , Proteínas Protozoarias/inmunología
20.
J Exp Med ; 182(5): 1435-45, 1995 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-7595214

RESUMEN

Vaccines designed to protect against malaria by inducing CD8+ cytotoxic T lymphocytes (CTL) in individuals of diverse HLA backgrounds must contain multiple conserved epitopes from various preerythrocytic-stage antigens. Plasmodium falciparum sporozoite surface protein 2 (PfSSP2) is considered an important antigen for inclusion in such vaccines, because CD8+ CTL against the P. yoelii SSP2 protect mice against malaria by eliminating infected hepatocytes. To develop PfSSP2 as a component of malaria vaccines, we investigated the presence of anti-PfSSP2 CTL in two HLA-B8+ volunteers immunized with irradiated P. falciparum sporozoites and characterized their CTL responses using PfSSP2-derived 15-amino acid peptides bearing the HLA-B8-binding motif. Peripheral blood mononuclear cells from both volunteers stimulated with recombinant vaccinia expressing PfSSP2 displayed antigen-specific, genetically restricted, CD8+ T cell-dependent CTL activity against autologous target cells expressing PfSSP2. Of the five HLA-B8 motif-bearing 15-mers identified in the PfSSP2 sequence, two peptides sharing a 10-amino acid overlap sensitized HLA-B8-matched target cells from both volunteers for lysis by peptide-stimulated effectors. The CTL activity was HLA-B8 restricted and dependent on CD8+ T cells. Analysis of the three shorter peptides representing HLA-B8 motif-bearing sequences within the two positive peptides for their ability to bind to HLA-B8 in vitro, and to sensitize target cells for lysis by effectors stimulated with the 15-mers, identified two overlapping HLA-B8-restricted CTL epitopes. Available data indicate that the sequence of one CTL epitope is conserved and the other is variant among P. falciparum isolates. Circulating activated CTL against the conserved epitope could be directly identified in one of the two volunteers. The identification of two HLA-B8-restricted CTL epitopes on PfSSP2 provides data critical to developing an epitope-based anti-liver stage malaria vaccine.


Asunto(s)
Antígenos de Protozoos/inmunología , Epítopos/inmunología , Antígeno HLA-B8/inmunología , Vacunas contra la Malaria/inmunología , Plasmodium falciparum/inmunología , Proteínas Protozoarias/inmunología , Linfocitos T Citotóxicos/inmunología , Secuencia de Aminoácidos , Animales , Culicidae/parasitología , Humanos , Inmunización , Activación de Linfocitos , Malaria Falciparum/prevención & control , Datos de Secuencia Molecular , Fragmentos de Péptidos/síntesis química , Fragmentos de Péptidos/inmunología , Plasmodium falciparum/crecimiento & desarrollo , Plasmodium falciparum/efectos de la radiación , Unión Proteica , Vacunas Atenuadas/inmunología , Vacunas Sintéticas/inmunología
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