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1.
Ultrasound Obstet Gynecol ; 56(5): 694-704, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-31682302

RESUMEN

OBJECTIVES: Our primary aim was to confirm whether intertwin discordance in ventricular strain and ductus venosus (DV) time intervals predicts twin-twin transfusion syndrome (TTTS). Secondary aims were to create gestational-age ranges for ventricular strain in uncomplicated monochorionic diamniotic (MCDA) twin pregnancies without selective intrauterine growth restriction (sIUGR) and to characterize the relationship of ventricular strain with gestational age in MCDA twin pregnancies with sIUGR that did not develop TTTS. METHODS: In the period 2015-2018, we enrolled 150 MCDA twin pregnancies consecutively into this prospective, blinded study of global longitudinal left and right ventricular strain. With the observer blinded to twin pairing and pregnancy outcome, videoclips of the four-chamber view, which had been recorded during ultrasound surveillance in the usual window for development of TTTS (16-26 completed gestational weeks), underwent offline measurement of strain. Uncomplicated MCDA twin pregnancies, without sIUGR, were used to test the association between strain, gestational age and estimated fetal weight using mixed-effects multilevel regression. Inter-rater reliability was tested in 208 strain measurements in 31 fetuses from pregnancies which did not develop TTTS and within-fetus variation was assessed in 16 such fetuses, in which multiple four-chamber views were taken on the same day. The effect of sIUGR on strain in otherwise uncomplicated MCDA twin pregnancy was analyzed. MCDA twin pregnancies were defined as 'pre-TTTS' when, having been referred for TTTS evaluation, they did not satisfy Quintero staging criteria, but subsequently developed TTTS requiring laser treatment. MCDA pregnancies which did not develop TTTS comprised the 'non-TTTS' group. Cardiovascular parameters measured in these cases included tissue Doppler parameters and DV early filling time as a percentage of the cardiac cycle (DVeT%). Intertwin strain and DVeT% discordance was compared between non-TTTS and pre-TTTS cases, matched for gestational age. RESULTS: Paired strain data were available for intertwin comparison in 127/150 MCDA twin pregnancies, comprising 14 pre-TTTS and 113 non-TTTS pregnancies, after exclusions. Scans were collected at a median frame rate of 97 (range, 28-220) Hz. Laser therapy was performed at a median gestational age of 20.6 (range, 17.2-26.6) weeks. There were no group differences in right (RV) or left (LV) ventricular strain discordance between 68/113 non-TTTS and 13/14 pre-TTTS MCDA twin pregnancies < 20 completed gestational weeks (RV, P = 0.338; LV, P = 0.932). DVeT% discordance > 3.6% was found in eight of 13 pre-TTTS pregnancies. In non-TTTS pregnancies, the estimated variability in ventricular strain within each twin during the day was high (RV, 19.7; LV, 12.9). However, within each pair (intertwin variation), variability was low (RV, 5.5; LV, 2.9). Interclass correlation reflecting the proportion of total variability represented by the variability between twin pairs was low (RV, 0.22; LV, 0.18). Both RV (P < 0.001) and LV (P = 0.025) strain showed a negative association with gestational age. Among non-TTTS MCDA twin pregnancies, LV strain was, on average, higher by 1.83 in sIUGR compared with normally grown fetuses (P = 0.023), with no statistically significant difference in RV strain (P = 0.271). CONCLUSIONS: Although ventricular strain has been reported previously as a possible predictor of developing TTTS, in this blinded, prospective study, we found no significant intergroup differences in ventricular strain in pre-TTTS compared with age-matched non-TTTS MCDA twin pregnancies. We recommend using DVeT% discordance as a more practical screening tool in MCDA twin pregnancies. This study also provides new information on the changes with gestational age, and the biological and technical variation, of global longitudinal ventricular strain in uncomplicated MCDA twin pregnancies and those with isolated sIUGR. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Corazón Fetal/fisiopatología , Feto/irrigación sanguínea , Ventrículos Cardíacos/fisiopatología , Embarazo Gemelar , Gemelos/estadística & datos numéricos , Adulto , Femenino , Retardo del Crecimiento Fetal/fisiopatología , Corazón Fetal/embriología , Peso Fetal , Transfusión Feto-Fetal/fisiopatología , Edad Gestacional , Ventrículos Cardíacos/embriología , Humanos , Análisis Multinivel , Circulación Placentaria , Embarazo , Estudios Prospectivos , Análisis de Regresión , Reproducibilidad de los Resultados , Método Simple Ciego , Ultrasonografía Prenatal
2.
Clin Exp Immunol ; 180(1): 108-17, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25425428

RESUMEN

Forkhead box protein 3 (FoxP3)(+) regulatory T cells (Tregs ) are important not only in regulating the development of autoimmune conditions, but also in chronic infectious diseases. Given their cardinal function in suppressing immune activation, research has focused upon whether they play a detrimental role in chronic infections, particularly HIV. While the role of Tregs in HIV has been investigated intensively, it remains an unresolved topic. However, it is generally accepted that Tregs are susceptible to HIV infection and are preferentially preserved over conventional CD4(+) T cells. It is unknown whether the peripheral-induced or the thymic-derived Tregs are more susceptible to HIV cytotoxicity. It has been recognized that Tregs can be segregated into two subsets based on Helios expression, with the vast majority being Helios(+) . This study examines the impact of HIV infection on total Tregs and their Helios subsets in a perinatal-acquired HIV-infected paediatric population. The finding indicates a selective expansion or survival of Tregs in association with CD4 depletion and increased viraemia. The Helios(+) and Helios(-) subsets within Tregs appear to be equally affected. However, the Helios(+) Tregs seem to be more preserved in patients with low CD4(+) ≤ 25% and detectable plasma HIV RNA >20 copies/ml. In this group, the frequencies of Tregs are increased, but their numbers appear insufficient to restrain immune activation. In conclusion, our findings suggest that both Helios subsets of Tregs are susceptible to HIV infection and are preferentially preserved compared to conventional CD4(+) T cells.


Asunto(s)
Factores de Transcripción Forkhead/inmunología , Regulación de la Expresión Génica/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Factor de Transcripción Ikaros/inmunología , Linfocitos T Reguladores/inmunología , Adolescente , Adulto , Niño , Preescolar , Enfermedad Crónica , Femenino , Factores de Transcripción Forkhead/biosíntesis , Infecciones por VIH/sangre , Infecciones por VIH/congénito , Infecciones por VIH/patología , VIH-1/metabolismo , Humanos , Factor de Transcripción Ikaros/biosíntesis , Lactante , Masculino , ARN Viral/sangre , ARN Viral/inmunología , Linfocitos T Reguladores/metabolismo , Linfocitos T Reguladores/patología , Timo/inmunología , Timo/metabolismo , Timo/patología
3.
Med Econ ; 70(7): 36-9, 43-4, 1993 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-10125391

RESUMEN

When an ophthalmologist questioned another M.D.'s professional ethics, he found himself facing a protracted lawsuit--one with disturbing implications for all physicians.


Asunto(s)
Oftalmología/legislación & jurisprudencia , Revisión por Pares/legislación & jurisprudencia , Arizona , Licencia Médica , Oftalmología/normas , Riesgo , Responsabilidad Social
7.
Med Econ ; 75(20): 48, 1998 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-10186288
17.
NIDA Res Monogr ; 48: 1-5, 1983.
Artículo en Inglés | MEDLINE | ID: mdl-6443140

RESUMEN

Overall, the issue is deceptively simple. There is a need to list the extant techniques which include some extensive recent advances. This should be followed by a simple hierarchical systematization of the techniques and definition of the requirements of each category of study. As is evident in the present volume, problems emerge in this effort. Nevertheless, it is clear that the effort could have considerable benefit, and further that it might serve as a model for biobehavioral research efforts. The present volume and its contributors provide many, though not all, of the essential ingredients, in an effort to move in this direction.


Asunto(s)
Fumar , Terapia Conductista , Humanos , Investigación , Tabaquismo/psicología
18.
NIDA Res Monogr ; 63: 221-8, 1985.
Artículo en Inglés | MEDLINE | ID: mdl-3934555

RESUMEN

For most youth, substance use appears to be the result, in large part, of social influences. Thus, teaching youth to resist these influences appears to be a reasonable approach to the prevention of use. However, it is not realistic to assume that all youth use for the same reason or respond to the same prevention approach. Moreover, identification of factors that act to promote or deter the transition from experimental or occasional use to abuse has not been addressed by these studies. While the social inoculation and social skills approaches appear to hold considerable promise for many youth, the research results indicate that a sizeable number of youth initiate and escalate use in spite of these programs. It appears that those youth who are most at risk for compulsive drug use are those who use drugs for reasons other than social influences (Robins and Przybeck 1985). Thus there is a need not to focus on any single prevention approach, but to explore multiple strategies. Identifying effective prevention approaches also requires the ability to target programs--to identify which types of individuals are effectively reached with a specific approach. Alternative programs, such as the cognitive-developmental approach described by Glynn, Leventhal, and Hirschman, warrant additional attention. A host of areas needing further research have been identified above. While the RAUS review participants did not establish priorities among areas, some attempt to do so is necessary since funds available for research are limited.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Trastornos Relacionados con Sustancias/prevención & control , Adolescente , Terapia Conductista , Niño , Cognición , Educación en Salud , Humanos , Grupo Paritario , Investigación , Prevención del Hábito de Fumar , Ajuste Social , Medio Social
19.
J Oral Maxillofac Surg ; 44(2): 100-3, 1986 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-3456013

RESUMEN

Twenty adult patients with maxillofacial discrepancies most amenable to correction by Le Fort I osteotomy were evaluated for the incidence of postoperative maxillary sinusitis. Before surgery, each patient was evaluated both radiographically, by Waters' projection technique, and subjectively, according to a brief questionnaire pertaining to sinus symptoms. Identical evaluations were carried out at three- and six-month intervals following surgery. The results show no increase in the incidence of maxillary sinusitis following Le Fort I osteotomy.


Asunto(s)
Maxilar/cirugía , Osteotomía/métodos , Sinusitis/epidemiología , Adolescente , Adulto , Femenino , Humanos , Masculino , Seno Maxilar/diagnóstico por imagen , Osteotomía/efectos adversos , Radiografía , Sinusitis/diagnóstico por imagen , Sinusitis/etiología
20.
Immunology ; 84(2): 213-9, 1995 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7750997

RESUMEN

Major basic protein, the primary constituent of eosinophil granules, regulates the alternative and classical pathways of complement. Major basic protein and other eosinophil granule cationic proteins, which are important in mediating tissue damage in allergic disease, regulate the alternative pathway by interfering with C3b interaction with factor B to assemble an alternative pathway C3 convertase. In the present study, eosinophil peroxidase, eosinophil cationic protein and eosinophil-derived neurotoxin, as well as major basic protein, were examined for capacity to regulate the classical pathway. Eosinophil peroxidase, eosinophil cationic protein and major basic protein inhibited formation of cell-bound classical pathway C3 convertase (EAC1,4b,2a), causing 50% inhibition of complement-mediated lysis at about 0.19, 0.75 and 0.5 micrograms/10(7) cellular intermediates, respectively. Eosinophil-derived neurotoxin had no activity on this pathway of complement. The eosinophil granule proteins were examined for activity on the formation of the membrane attack complex. Major basic protein and eosinophil cationic protein had no activity on terminal lysis. In contrast, eosinophil peroxidase inhibited lysis of EAC1,4b,2a,3b,5b, but had only minimal activity on later events in complement lysis. These polycations were then examined to determine the site(s) at which they regulated the early classical pathway. Eosinophil granule polycationic proteins: (1) reduced the Zmax at all time points but had only minimal effect on the Tmax during the formation of the classical pathway C3 convertase (EAC1,4b,2a); (2) inhibited formation of EAC1,4b,2a proportional to C4 but independent of C2 concentration; (3) inhibited fluid phase formation of C1,4b,2a, as reflected by a decrease in C1-induced consumption of C2 over time; and (4) inhibited C1 activity over time without a direct effect on either C4 or C2. These observations suggest that polycations regulate the early classical pathway by interfering with C1 and may exert this activity in vivo.


Asunto(s)
Proteínas Sanguíneas/farmacología , Vía Clásica del Complemento/efectos de los fármacos , Neurotoxinas/farmacología , Peroxidasas/farmacología , Ribonucleasas , Complemento C3/efectos de los fármacos , Complemento C4/efectos de los fármacos , Proteínas en los Gránulos del Eosinófilo , Peroxidasa del Eosinófilo , Neurotoxina Derivada del Eosinófilo , Humanos
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