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1.
Neuroimage ; 141: 490-501, 2016 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-27421183

RESUMEN

Network theory provides a principled abstraction of the human brain: reducing a complex system into a simpler representation from which to investigate brain organisation. Recent advancement in the neuroimaging field is towards representing brain connectivity as a dynamic process in order to gain a deeper understanding of how the brain is organised for information transport. In this paper we propose a network modelling approach based on the heat kernel to capture the process of heat diffusion in complex networks. By applying the heat kernel to structural brain networks, we define new features which quantify change in heat propagation. Identifying suitable features which can classify networks between cohorts is useful towards understanding the effect of disease on brain architecture. We demonstrate the discriminative power of heat kernel features in both synthetic and clinical preterm data. By generating an extensive range of synthetic networks with varying density and randomisation, we investigate heat diffusion in relation to changes in network topology. We demonstrate that our proposed features provide a metric of network efficiency and may be indicative of organisational principles commonly associated with, for example, small-world architecture. In addition, we show the potential of these features to characterise and classify between network topologies. We further demonstrate our methodology in a clinical setting by applying it to a large cohort of preterm babies scanned at term equivalent age from which diffusion networks were computed. We show that our heat kernel features are able to successfully predict motor function measured at two years of age (sensitivity, specificity, F-score, accuracy = 75.0, 82.5, 78.6, and 82.3%, respectively).


Asunto(s)
Encéfalo/diagnóstico por imagen , Encéfalo/patología , Imagen de Difusión por Resonancia Magnética/métodos , Interpretación de Imagen Asistida por Computador/métodos , Reconocimiento de Normas Patrones Automatizadas/métodos , Nacimiento Prematuro/diagnóstico por imagen , Nacimiento Prematuro/patología , Femenino , Calor , Humanos , Masculino , Red Nerviosa/diagnóstico por imagen , Red Nerviosa/patología , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Termodinámica
2.
Cereb Cortex ; 24(9): 2324-33, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23547135

RESUMEN

Cerebral white-matter injury is common in preterm-born infants and is associated with neurocognitive impairments. Identifying the pattern of connectivity changes in the brain following premature birth may provide a more comprehensive understanding of the neurobiology underlying these impairments. Here, we characterize whole-brain, macrostructural connectivity following preterm delivery and explore the influence of age and prematurity using a data-driven, nonsubjective analysis of diffusion magnetic resonance imaging data. T1- and T2-weighted and -diffusion MRI were obtained between 11 and 31 months postconceptional age in 49 infants, born between 25 and 35 weeks postconception. An optimized processing pipeline, combining anatomical, and tissue segmentations with probabilistic diffusion tractography, was used to map mean tract anisotropy. White-matter tracts where connection strength was related to age of delivery or imaging were identified using sparse-penalized regression and stability selection. Older children had stronger connections in tracts predominantly involving frontal lobe structures. Increasing prematurity at birth was related to widespread reductions in connection strength in tracts involving all cortical lobes and several subcortical structures. This nonsubjective approach to mapping whole-brain connectivity detected hypothesized changes in the strength of intracerebral connections during development and widespread reductions in connectivity strength associated with premature birth.


Asunto(s)
Encéfalo/anatomía & histología , Encéfalo/crecimiento & desarrollo , Recien Nacido Prematuro/crecimiento & desarrollo , Desarrollo Infantil , Preescolar , Conectoma , Imagen de Difusión por Resonancia Magnética , Imagen de Difusión Tensora , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Lactante , Masculino , Fibras Nerviosas Mielínicas , Vías Nerviosas/anatomía & histología , Vías Nerviosas/crecimiento & desarrollo , Sustancia Blanca/anatomía & histología , Sustancia Blanca/crecimiento & desarrollo
3.
Clin Exp Allergy ; 42(3): 471-80, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22356145

RESUMEN

BACKGROUND: Parietaria pollen is one of the major cause of pollinosis in the southern Europe. Specific immunotherapy is the only treatment able to modify the natural outcome of the disease restoring a normal immunity against allergens. METHODS: We designed a recombinant molecule (PjEDloop1) comprised of genetic-engineered variants of the major allergens of the Parietaria pollen (Par j 2/Par j 1). Purity and chemical-physical properties of the derivative were analysed by RP-HPLC chromatography and Photon Correlation Spectroscopy. Immunological activity was evaluated by means of Western blotting, ELISA inhibition and PBMC proliferation assay in 10 Parietaria allergic patients. Basophil activation was studied in six subjects. The immunogenicity of the hybrid was studied looking at the immune responses induced in a mouse model of sensitization. RESULTS: The PjEDloop1 hybrid was produced as a purified recombinant protein with high stability in solution. Western blot, ELISA inhibition and basophil activation test showed that the PjEDloop1 displays a remarkable reduced IgE binding and anaphylactic activity. CD3 reactivity was conserved in all patients. Mice immunization with the rPjEDloop1 induced antibodies and T cell responses comparable to that obtained by the wild type allergens. Such antibodies shared the specificities to rPar j 1 and rPar j 2 with human IgE antibodies. CONCLUSION: Our results demonstrated that a mutant hybrid expressing genetically engineered forms of the major P. judaica allergens displayed reduced allergenicity and retained T cell reactivity for the induction of protective antibodies in vaccination approaches for the treatment of Parietaria pollinosis.


Asunto(s)
Alérgenos/inmunología , Desensibilización Inmunológica/métodos , Parietaria/inmunología , Proteínas de Plantas/inmunología , Animales , Antígenos de Plantas , Western Blotting , Cromatografía Líquida de Alta Presión , Ensayo de Inmunoadsorción Enzimática , Femenino , Citometría de Flujo , Ingeniería Genética/métodos , Humanos , Ratones , Ratones Endogámicos BALB C , Mutagénesis Sitio-Dirigida , Proteínas Recombinantes/síntesis química , Proteínas Recombinantes/inmunología , Rinitis Alérgica Estacional/terapia
4.
Epidemiol Psychiatr Sci ; 31: e19, 2022 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-35352676

RESUMEN

AIMS: Lower parental education has been linked to adverse youth mental health outcomes. However, the relationship between parental education and youth suicidal behaviours remains unclear. We explored the association between parental education and youth suicidal ideation and attempts, and examined whether sociocultural contexts moderate such associations. METHODS: We conducted a systematic review and meta-analysis with a systematic literature search in PubMed, PsycINFO, Medline and Embase from 1900 to December 2020 for studies with participants aged 0-18, and provided quantitative data on the association between parental education and youth suicidal ideation and attempts (death included). Only articles published in English in peer-reviewed journals were considered. Two authors independently assessed eligibility of the articles. One author extracted data [e.g. number of cases and non-cases in each parental education level, effect sizes in forms of odds ratios (ORs) or beta coefficients]. We then calculated pooled ORs using a random-effects model and used moderator analysis to investigate heterogeneity. RESULTS: We included a total of 59 articles (63 study samples, totalling 2 738 374 subjects) in the meta-analysis. Lower parental education was associated with youth suicidal attempts [OR = 1.12, 95% Confidence Interval (CI) = 1.04-1.21] but not with suicidal ideation (OR = 1.05, 95% CI = 0.98-1.12). Geographical region and country income level moderated the associations. Lower parental education was associated with an increased risk of youth suicidal attempts in Northern America (OR = 1.26, 95% CI = 1.10-1.45), but with a decreased risk in Eastern and South-Eastern Asia (OR = 0.72, 95% CI = 0.54-0.96). An association of lower parental education and increased risk of youth suicidal ideation was present in high- income countries (HICs) (OR = 1.14, 95% CI = 1.05-1.25), and absent in low- and middle-income countries (LMICs) (OR = 0.91, 95% CI = 0.77-1.08). CONCLUSIONS: The association between youth suicidal behaviours and parental education seems to differ across geographical and economical contexts, suggesting that cultural, psychosocial or biological factors may play a role in explaining this association. Although there was high heterogeneity in the studies reviewed, this evidence suggests that the role of familial sociodemographic characteristics in youth suicidality may not be universal. This highlights the need to consider cultural, as well as familial factors in the clinical assessment and management of youth's suicidal behaviours in our increasingly multicultural societies, as well as in developing prevention and intervention strategies for youth suicide.


Asunto(s)
Ideación Suicida , Suicidio , Adolescente , Niño , Preescolar , Escolaridad , Humanos , Lactante , Recién Nacido , Padres , Pobreza
5.
Sci Total Environ ; 750: 142283, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33182218

RESUMEN

The deterioration of monument or building stone materials is mostly due to the growth of black crusts that cause blackening and disaggregation of the exposed surface. This study reports on new oxygen (δ17O, δ18O and Δ17O) and sulphur (δ33S, δ34S, δ36S, Δ33S and Δ36S) isotopic analyses of black crust sulphates formed on building stones in Sicily (Southern Italy). The measurements are used to identify the possible influence of volcanic emissions on black crust formation. Black crusts were mostly sampled on carbonate stone substrate in different locations subject to various sulphur emission sources (marine, anthropogenic and volcanic). Unlike atmospheric sulphate aerosols that mostly exhibit Δ33S > 0‰, here most of the analysed black crust sulphates show negative Δ33S. This confirms that black crust sulphates do not result from deposition of sulphate aerosols or of rainwater but mostly from the oxidation of dry deposited SO2 onto the stone substrate. The δ34S and δ18O values indicate that most of black crust sulphate originates from anthropogenic activities. Δ17O values are found to be related to the sampling location. The largest 17O-anomalies (up to ~4‰) are measured in black crust from areas highly influenced by volcanic emissions, which demonstrates the strong involvement of ozone in the formation of black crusts in volcanically influenced environments.

6.
FASEB J ; 20(11): 1916-7, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16818470

RESUMEN

A distinctive feature of Alzheimer's disease is the deposition of amyloid beta-protein (Abeta) in senile or diffuse plaques. The 42 residue beta-peptide (Abeta42) is the predominant form found in plaques. In the present work we report a high-yield expression and purification method of production of a recombinant Abeta42. The purified recombinant peptide shows characteristics similar to the synthetic human peptide. Different size aggregates, either small oligomers or larger aggregates, were obtained upon dissolving the recombinant Abeta42 peptide under different conditions at pH 7.2 or pH 3, respectively. We report a new toxicity assay on the morphogenic development of the sea urchin Paracentrotus lividus and study the toxicity of the two kinds of aggregates. Despite the difference between the ionic strength of human extracellular fluid (0.154 mol/l) and artificial sea water (0.48 mol/l), toxicity data collected in this system have an intrinsic relevance. The different ionic strength, in fact, could change the kinetics of oligomer formation, but the effect of morphogenic development reported here is related to the final oligomer sizes. Results of the toxicity assay of Abeta42 on sea urchin development also show a dose-dependent effect. After only 4 h of embryo development, one can note morphological defects in the cell membrane. Retardation of the embryo's development, along with cellular disorders visible inside the blastocoele, can be observed after 1 day of development. Cellular degeneration in two different pathological phenotypes-the occluded blastulae and the occluded prism-is present after 48 h of development. Results show that a greater effect on cell death is induced by the small oligomers stabilized under physiological conditions than at acid pH. In this case only occluded blastulae are found after 48 h of development.


Asunto(s)
Péptidos beta-Amiloides/toxicidad , Embrión no Mamífero/efectos de los fármacos , Paracentrotus/embriología , Fragmentos de Péptidos/toxicidad , Animales , Secuencia de Bases , Clonación Molecular , Cartilla de ADN , Humanos , Morfogénesis/efectos de los fármacos , Paracentrotus/efectos de los fármacos , Proteínas Recombinantes/toxicidad , Mapeo Restrictivo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
7.
J Clin Oncol ; 10(10): 1553-60, 1992 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1383433

RESUMEN

PURPOSE: Recent reports suggest an increasing incidence of CNS metastases in patients with ovarian cancer. We reviewed our experience in the management of brain metastases from ovarian carcinoma and merged our results with those of several other series reported in the literature to determine prognostic factors and the role of chemotherapy, radiation therapy, and surgery. PATIENTS AND METHODS: From 1977 to 1990, 15 of 795 patients who were treated for epithelial ovarian cancer at Duke University developed brain metastases. Fourteen of the patients were treated for their brain metastases; this included radiation therapy (RT; four), surgery and RT (one), RT and systemic chemotherapy (six), and all three treatment modalities (three). A meta-analysis was performed that combined the data from the current series with those of several recent clinical series that reviewed patients with brain metastases from ovarian carcinoma (67 patients total) to elucidate the impact of treatment and extent of disease on survival. RESULTS: In the current series, median survival (MS) after the diagnosis of brain metastases was 9 months. For the combined series, MS was 5 months. Thirteen patients who were treated with whole-brain RT and systemic chemotherapy (MS, 7 months), 10 patients who were treated with RT and surgery (MS, 10 months), and nine patients who were treated with all three modalities (MS, 16.5 months) had significantly longer survival than 19 patients who were treated with RT alone (MS, 3 months) (P = .05, P = .01, and P < .001, respectively). In a multivariate analysis, the only variable that provided prognostic information was treatment, namely the addition of systemic chemotherapy or surgery to RT for the treatment of brain metastases. CONCLUSION: Multimodal treatment of patients with brain metastases from ovarian cancer can result in significant palliation.


Asunto(s)
Neoplasias Encefálicas/terapia , Carcinoma/terapia , Neoplasias Ováricas/patología , Cuidados Paliativos/métodos , Adulto , Anciano , Neoplasias Encefálicas/secundario , Carcinoma/secundario , Terapia Combinada , Femenino , Humanos , Persona de Mediana Edad , Pronóstico , Análisis de Regresión , Estudios Retrospectivos , Análisis de Supervivencia
8.
Mech Dev ; 99(1-2): 113-21, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11091079

RESUMEN

COLL1alpha mRNA is asymmetrically distributed in the Paracentrotus lividus egg. Here we examine the involvement of the cytoskeleton in the localization process of collagen mRNA. The use of drugs such as colchicine and cytochalasin B reveals a perturbation of localization collagen mRNA. Moreover, the presence of specific cis-and trans-acting factors involved in cytoskeleton binding and the localization process was investigated. By Northwestern experiment we found that the 3'UTR of COLL1alpha mRNA is also able to bind two proteins of 54 and 40 kDa in a cellular fraction containing the cytoskeleton. Finally, we found that the protein of 54 kDa is LP54, a protein that binds the 3'UTRs of P. lividus maternal bep messengers and is necessary for their localization.


Asunto(s)
Colágeno/biosíntesis , Colágeno/genética , Colágeno/metabolismo , Citoesqueleto/metabolismo , Óvulo/metabolismo , ARN Mensajero/metabolismo , Erizos de Mar/embriología , Activación Transcripcional , Regiones no Traducidas 3' , Animales , Northern Blotting , Fraccionamiento Celular , Colchicina/farmacología , Citocalasina B/farmacología , ADN Complementario/metabolismo , Electroforesis en Gel de Agar , Electroforesis en Gel de Poliacrilamida , Immunoblotting , Inmunohistoquímica , Hibridación in Situ , Microtúbulos/metabolismo , Óvulo/efectos de los fármacos , Unión Proteica , Proteínas de Unión al ARN/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
9.
Clin Cancer Res ; 5(9): 2476-84, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10499622

RESUMEN

In this report, we use new patient data to test three popular models developed to predict the outcome of definitive radiation therapy. The data come from 240 men with localized prostate cancer and who were treated with definitive radiation therapy at a community hospital. All three models tested were based on the three commonly available variables of pretreatment prostate-specific antigen (PSA), Gleason score, and tumor stage, and we used the Cox proportional hazards model and the logistic regression model to relate these variables to outcome. We discovered that in our data, the optimal way to use pretreatment PSA was as natural log(PSA), the optimal way to use T stage was in three categories: T1 and T2, T3, and T4, and that the optimal use of Gleason score was as <7 versus > or =7. Nevertheless, models confined to the optimal use of these three variables leave much uncertainty about important outcomes, such as the probability of relapse within 5 years.


Asunto(s)
Modelos Estadísticos , Antígeno Prostático Específico/análisis , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/radioterapia , Anciano , Anciano de 80 o más Años , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Valor Predictivo de las Pruebas , Pronóstico , Modelos de Riesgos Proporcionales , Resultado del Tratamiento
10.
Clin Cancer Res ; 5(12): 4119-25, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10632349

RESUMEN

We report the use of an exponential model for capturing the dynamics of serial measurements of prostate-specific antigen (PSA) made just before and after definitive radiation therapy of localized prostate cancer. Our study patients consisted of 164 men treated at a community hospital and without use of adjuvant hormonal therapy, and we had a mean of 5 years follow-up. We found that the model fits allowed us to condense PSA dynamic information into four parameters, including the initial pretreatment value of PSA, and three of these related significantly to subsequent outcome. The model also provided greater understanding of the prognosis of men with rising PSA after radiation therapy. Specifically, two of the model's parameters allowed us to compare the PSA status of these men to those with hormone-refractory disease, and we discovered that at the time of "biochemical relapse," there is a broad spectrum in expected probability of imminent death as well as in time to an adverse outcome. Thus, the model provides information that allows one to stratify men with rising PSA into a continuous spectrum from low to high risk for an adverse outcome. We believe these results show that exponential models have the potential for providing useful clinical information about men with rising PSA after definitive radiation therapy and that they could help us decide when further therapy is needed. Therefore, we recommend further study and development of these models as part of clinical research protocols involving radiation therapy of localized prostate cancer.


Asunto(s)
Modelos Biológicos , Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/sangre , Neoplasias de la Próstata/cirugía , Estudios de Seguimiento , Humanos , Masculino , Cómputos Matemáticos , Recurrencia Local de Neoplasia , Valor Predictivo de las Pruebas , Pronóstico , Modelos de Riesgos Proporcionales , Resultado del Tratamiento
11.
Gene ; 141(2): 243-8, 1994 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-8163196

RESUMEN

We report the nucleotide sequence of a fragment of DNA derived from a sea urchin genomic clone containing the cell surface Bep4 (butanol-extracted protein 4)-encoding gene. The structural gene is interrupted by four introns and the promoter region contains TATA and CAAT consensus motifs. The transcription start point (tsp) was also determined. Remarkable homologies, between Bep4 and other proteins known to be involved in cell interactions, were observed regarding two potential Ca(2+)-binding sites and the corresponding DNA consensus sequences. We also report the conservation of the bep4 gene and its corresponding Bep4 protein between various sea urchin species by way of Southern and Western blotting.


Asunto(s)
Proteínas de la Membrana/genética , Erizos de Mar/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , Secuencia de Consenso , Genes , Datos de Secuencia Molecular , Iniciación de la Cadena Peptídica Traduccional , Regiones Promotoras Genéticas , Homología de Secuencia de Aminoácido , TATA Box
12.
FEBS Lett ; 425(1): 157-60, 1998 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-9541027

RESUMEN

Bep mRNAs are localized at the animal pole of P. lividus eggs. In the present communication the secondary structures of the 3'UTRs of the bep1, bep3 and bep4 mRNAs are reported. The minimal lengths of these regions required to bind the 54-kDa protein, previously shown to be involved in localization and anchoring of these RNAs, is estimated. Microinjection of the bep3 3'UTR into egg shows that this RNA fragment is also able to become localized to one of the egg poles, as happens for the entire bep3 RNA.


Asunto(s)
Hormonas de Invertebrados/metabolismo , Proteínas de la Membrana/metabolismo , Pliegue de Proteína , Secuencia de Aminoácidos , Animales , Hormonas de Invertebrados/química , Hormonas de Invertebrados/genética , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Microinyecciones , Datos de Secuencia Molecular , Biosíntesis de Proteínas , Estructura Secundaria de Proteína , ARN Mensajero/genética , Erizos de Mar
13.
Int J Radiat Oncol Biol Phys ; 37(2): 455-63, 1997 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-9069321

RESUMEN

PURPOSE: Intracavitary dose prescription for cancer of the uterine cervix has been based on the use of plane orthogonal films. Computed tomography (CT) and magnetic resonance imaging can provide three-dimensional (3D) anatomic information with which more sophisticated treatment planning can be carried out. This work describes a new tandem and ovoids design that permits modern 3D dosimetry and has the same placement flexibility for the physician as the applicators currently being used. METHODS AND MATERIALS: The external shape of the Fletcher-Suit-Delclos (FSD) minicolpostat tandem and ovoids system has been used as a model to build a prototype of a new applicator. The prototype colpostats are constructed out of aluminum and steel. The tandems are made of aluminum. The Fletcher shields are eliminated. A new method of using tungsten for dose attenuation and shielding has been designed. Longitudinal alignment of the tungsten shields makes the new system possible. This applicator is CT-compatible. RESULTS: Dose calculations for the new design are compared to a commercial version of the FSD applicator. Both the aluminum prototype and a simple extension of the prototype to a plastic applicator system are considered. It is shown that the principal difference in dose is that the dose is reduced in the region inferior to the center of the ovoids. All configurations (plastic caps on or off) are equivalently shielded for the new device. In addition, an intermediate mini-ovoid configuration can be used clinically via the introduction of a D-shaped cap. The latter reduces the high dose to the vaginal mucosal surfaces. CONCLUSION: For a single ovoid, a comparison of dose with the FSD shows differences; however, the difference in dose is insignificant when the complete applicator, tandem, and ovoids are compared. With this new applicator, it is now possible to accumulate very accurate and detailed 3D dose-distribution data for the critical structures and other points of interest in the vicinity of the applicator. These data will permit future analysis of the correlation of dose and outcome for carcinoma of the cervix.


Asunto(s)
Braquiterapia/instrumentación , Radiometría/instrumentación , Neoplasias del Cuello Uterino/radioterapia , Diseño de Equipo , Femenino , Humanos , Protección Radiológica , Dosificación Radioterapéutica
14.
Int J Radiat Oncol Biol Phys ; 16(1): 95-100, 1989 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-2912959

RESUMEN

From April 1969 through December 1980, 527 patients with epidermoid carcinoma of the cervix received radical radiation therapy at North Carolina Memorial Hospital (NCMH). The treatment was designed to deliver a combined dose (external beam plus intracavitary) of 7000-8000 cGy to Point A and 5000-6500 cGy to the pelvic lymph nodes depending upon the stage of the disease. The maximum dose to the bladder and to the rectum were calculated from the orthogonal intracavitary placement films with contrast material in these organs. Thirty-three cases of cystitis and fifty-eight cases of proctitis were recorded. The mean bladder dose for the group of patients with cystitis was higher, 6661 +/- 1309 cGy, than that for the patients without cystitis, 6298 +/- 1305 cGy, p = .19. The risk of cystitis increased as a function of bladder dose ranging from 3% for patients receiving less than or equal to 5000 cGy to the bladder to 12% for patients receiving greater than or equal to 8001 cGy to the bladder. A similar correlation was also found for rectal dose and proctitis. The mean rectal dose for the group of patients with proctitis was higher, 6907 +/- 981 cGy, than that for the patients without proctitis, 6381 +/- 1290 cGy, p = .003. The risk of proctitis increased as a function of rectal dose ranging from 2% for patients receiving less than or equal to 5000 cGy to the rectum to 18% for patients receiving greater than or equal to 8001 cGy to the rectum. A study of the severity of the cystitis as a function of bladder dose revealed a relationship between bladder dose and the severity of the complication (Grade I cystitis = 6600 +/- 1318 cGy vs Grade III cystitis = 6856 +/- 853 cGy). A dose-response relationship was found between the rectal dose and the severity of the complication (Grade I proctitis = 6810 +/- 906 cGy vs Grade III proctitis = 6997 +/- 1137 cGy). This relationship was statistically significant, p = .003. While there was no difference in the frequency of cystitis as a function of dose to the whole pelvis, the risk of proctitis did increase with increasing doses of external beam to the whole pelvis. It ranged from 3% for patients who received 2000 cGy or less to the whole pelvis to 14% for patients who received greater than 4000 cGy to the whole pelvis, p = .02.


Asunto(s)
Carcinoma de Células Escamosas/radioterapia , Radioterapia/efectos adversos , Recto/efectos de la radiación , Vejiga Urinaria/efectos de la radiación , Neoplasias del Cuello Uterino/radioterapia , Braquiterapia/efectos adversos , Cistitis/etiología , Femenino , Humanos , Proctitis/etiología , Dosis de Radiación , Obstrucción Ureteral/etiología
15.
Int J Radiat Oncol Biol Phys ; 20(1): 87-93, 1991 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-1993634

RESUMEN

Patterns of Care Study (PCS) conducted the second survey of carcinoma of the cervix in 1978. The data of this survey are derived from 565 patient questionnaires completed from 120 randomly selected facilities. Through these surveys PCS has set out to establish a profile of the practice of radiation therapy in the United States as well as determine the survival, local control rates, patterns of recurrence, complications, and relationship of these events with dose. This study deals with the patterns and sites of failure and relationship with dose to the paracentral and lateral points previously defined. The breakdown of patients according to the stage was as follows: Stage I = 203, Stage II = 243, Stage III = 115, undertermined = 4. Twenty-three percent of the patients failed within the field of irradiation, whereas 9% failed outside of the irradiated field. The infield failure rate increased as a function of stage from 9% in Stage I to 23% in Stage II and 48% in Stage III. Distant metastasis was the first site of failure in 4% of patients with Stage I, 7% for Stage II, 9% for Stage III, and 6% for the entire group. The cervix and vagina were the first site of recurrence in 20% of the patients. The cervical/vaginal recurrence rate increased as a function of stage from 7% in Stage I to 21% in Stage II, and 37% in Stage III. An analysis of the cervical/vaginal recurrences as a function of the average total dose to the paracentral points showed a decreased recurrence rate as a function of dose within the range of less than 6500 to 7999 cGy. The recurrence rate at 4 years decreased from 34% with a dose of less than 6500 cGy to 14% with a dose of 7500-7999 cGy. Above this dose level, this correlation of dose with recurrence was not observed. This correlation was also absent when the patients were studied according to the stage of the disease. The relationship of parametrial/sidewall failure and average dose to the lateral point was studied also, but no correlation was found except for patients with Stage III disease. The disease-free survival was studied for the entire group of patients and for the different stages as a function of average paracentral dose: less than 7500 cGy, 7500 to 8500 cGy, and greater than 8500 cGy. The disease-free survival was lower for the patients in the less than 7500 cGy group.(ABSTRACT TRUNCATED AT 400 WORDS)


Asunto(s)
Neoplasias del Cuello Uterino/radioterapia , Adulto , Anciano , Braquiterapia , Protocolos Clínicos , Femenino , Humanos , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Evaluación de Procesos y Resultados en Atención de Salud/estadística & datos numéricos , Análisis de Supervivencia , Tasa de Supervivencia , Neoplasias del Cuello Uterino/mortalidad , Neoplasias del Cuello Uterino/patología
16.
Int J Radiat Oncol Biol Phys ; 21(4): 1045-52, 1991 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-1917601

RESUMEN

A plastic intracavitary applicator system for the treatment of cancer of the uterine cervix is described. This applicator has a minicolpostat and a mechanism for affixing the tandem to the colpostats. Traditional afterloading refers only to the radioactive source. Both the source and the ovoid shield are afterloaded together in this applicator in contrast to traditional afterloading systems which afterload the source alone. A potential advantage of our applicator system is that it allows high quality CT localization because the sources and shields can be removed and the applicator is made of plastic. The advantages and disadvantages of this variation to the Fletcher system as well as other aspects of applicator design are discussed. An experimentally verified dose calculation method for shielded sources is applied to the design problems associated with this applicator. The dose distribution calculated for a source-shield configuration of the plastic applicator is compared to that obtained with a commercial Fletcher-Suit-Delclos (FSD) applicator. Significant shielding improvements can be achieved for the smallest diameter ovoid, that is, in the minicolpostat. The plastic minicolpostat dose distributions are similar to those produced by the conventional larger diameter colpostats. In particular, the colpostat shielding for rectum and bladder, which is reduced in the metal applicator's minicolpostat configuration, is maintained for the plastic minicolpostat. Further, it is shown that, if desired, relative to the FSD minicolpostat, the mucosa dose can be reduced by a suitable change of the minicolpostat source position.


Asunto(s)
Braquiterapia/instrumentación , Neoplasias del Cuello Uterino/radioterapia , Diseño de Equipo , Femenino , Humanos , Plásticos , Protección Radiológica/instrumentación
17.
Int J Radiat Oncol Biol Phys ; 19(3): 751-8, 1990 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2211223

RESUMEN

A technique is described for the design and construction of customized templates for transperineal implants and interstitial hyperthermia of pelvic malignancies. The design of the template and the distribution of the transperineal Iridium-192 seed ribbons are based on prior optimization of the dose distribution. The target volume is defined by means of pelvic examination and pertinent radiographic studies including a CT. The pelvic CT study is obtained with a plastic obturator in the rectum or the vagina. The obturator is used as a reference structure for aligning the target contour from each image plane to form a composite 2-dimensional contour of maximum tumor extent in a plane perpendicular to the obturator. Dose distributions are calculated to determine the placement of the Iridium-192 seed ribbons in the template. Laparoscopic guidance is used for actual placement of brachytherapy source needles together with a rectal or vaginal obturator to stabilize the template and to assure that the needle placement conforms with the planned geometry. Dose distributions for 10 consecutive patients calculated for customized templates as well as for five commercially available standard templates show that the customized templates are superior to standard templates in that the planned dose distribution matches the configuration of the target volume and is more uniform than with standard templates.


Asunto(s)
Braquiterapia/instrumentación , Radioisótopos de Iridio/uso terapéutico , Neoplasias Pélvicas/radioterapia , Prótesis e Implantes , Adulto , Anciano , Estudios de Evaluación como Asunto , Femenino , Humanos , Radioisótopos de Iridio/administración & dosificación , Persona de Mediana Edad , Perineo , Polímeros , Dosificación Radioterapéutica
18.
Int J Radiat Oncol Biol Phys ; 32(2): 317-23, 1995 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-7538500

RESUMEN

PURPOSE: To determine the efficacy of radiotherapy (RT) in patients with an isolated elevation of prostate specific antigen (PSA) after radical prostatectomy (RP). METHODS AND MATERIALS: Between November 1987 and May 1993, 53 patients with adenocarcinoma of the prostate were referred for pelvic RT for an elevated PSA after RP. No patient had clinically or radiographically apparent local or distant disease, nor had an undergone prior androgen ablation. Patients received a median dose of 61.2 Gy to the prostatic bed. An undetectable PSA was required to be considered disease free (NED). Univariate and multivariate analyses were performed to identify factors predictive of becoming disease free after RT. RESULTS: The median follow-up was 15 months. Of the 53 patients, 16 (30%) became NED after RT and 15 (28%) had a declining (n = 11) or stable (n = 4) PSA at last evaluation. The median time after RT to achieve an undetectable PSA was 9.3 months. At 12 and 24 months, the actuarial disease-free survival was 30 and 23%, respectively; actuarial progression-free survival was 71 and 26%, respectively. By univariate analysis, the last PSA level before RT (i.e., the pre-RT PSA) and an undetectable PSA after RP were significant predictors of becoming NED (p = 0.0001 and 0.04, respectively). However, on multivariate analysis, only the pre-RT PSA remained significant (p = 0.01). The mean pre-RT PSA differed significantly between patients who became NED after RT and those who did not (1.5 +/- 0.2 ng/ml vs. 7.6 +/- 1.6 ng/ml, respectively; p = 0.018). Fourteen of 27 (52%) patients with pre-RT PSA levels < or = 2.5 ng/ml became NED, vs. only 2 of 26 (8%) patients with higher levels. There were no severe acute or late sequelae of RT. CONCLUSION: Prostatic-bed RT for an elevated serum PSA after RP is most effective in patients with a pre-RT PSA < or = 2.5 ng/ml. Patients with significantly higher PSA values are unlikely to benefit from RT, possibly due to the presence of occult distant metastases. The optimal therapy for this latter group remains to be determined.


Asunto(s)
Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/sangre , Neoplasias de la Próstata/radioterapia , Anciano , Neoplasias Óseas/secundario , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Pronóstico , Prostatectomía , Neoplasias de la Próstata/mortalidad , Neoplasias de la Próstata/cirugía
19.
Int J Radiat Oncol Biol Phys ; 42(1): 79-85, 1998 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-9747823

RESUMEN

PURPOSE: To determine the feasibility of using preoperative chemoradiotherapy to avert the need for more radical surgery for patients with T3 primary tumors, or the need for pelvic exenteration for patients with T4 primary tumors, not amenable to resection by standard radical vulvectomy. METHODS AND MATERIALS: Seventy-three evaluable patients with clinical Stage III-IV squamous cell vulvar carcinoma were enrolled in this prospective, multi-institutional trial. Treatment consisted of a planned split course of concurrent cisplatin/5-fluorouracil and radiation therapy followed by surgical excision of the residual primary tumor plus bilateral inguinal-femoral lymph node dissection. Radiation therapy was delivered to the primary tumor volume via anterior-posterior-posterior-anterior (AP-PA) fields in 170-cGy fractions to a dose of 4760 cGy. Patients with inoperable groin nodes received chemoradiation to the primary vulvar tumor, inguinal-femoral and lower pelvic lymph nodes. RESULTS: Seven patients did not undergo a post-treatment surgical procedure: deteriorating medical condition (2 patients); other medical condition (1 patient); unresectable residual tumor (2 patients); patient refusal (2 patients). Following chemoradiotherapy, 33/71 (46.5%) patients had no visible vulvar cancer at the time of planned surgery and 38/71 (53.5%) had gross residual cancer at the time of operation. Five of the latter 38 patients had positive resection margins and underwent: further radiation therapy to the vulva (3 patients); wide local excision and vaginectomy necessitating colostomy (1 patient); no further therapy (1 patient). Using this strategy of preoperative, split-course, twice-daily radiation combined with cisplatin plus 5-fluorouracil chemotherapy, only 2/71 (2.8%) had residual unresectable disease. In only three patients was it not possible to preserve urinary and/or gastrointestinal continence. Toxicity was acceptable, with acute cutaneous reactions to chemoradiotherapy and surgical wound complications being the most common adverse effects. CONCLUSION: Preoperative chemoradiotherapy in advanced squamous cell carcinoma of the vulva is feasible, and may reduce the need for more radical surgery including primary pelvic exenteration.


Asunto(s)
Carcinoma de Células Escamosas/terapia , Neoplasias de la Vulva/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/radioterapia , Carcinoma de Células Escamosas/cirugía , Cisplatino/administración & dosificación , Terapia Combinada , Estudios de Factibilidad , Femenino , Fluorouracilo/administración & dosificación , Humanos , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Prospectivos , Dosificación Radioterapéutica , Resultado del Tratamiento , Neoplasias de la Vulva/tratamiento farmacológico , Neoplasias de la Vulva/patología , Neoplasias de la Vulva/radioterapia , Neoplasias de la Vulva/cirugía
20.
Int J Radiat Oncol Biol Phys ; 24(4): 633-42, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1429085

RESUMEN

From 1984-1990, 143 patients with squamous cell or adenocarcinoma of the esophagus were enrolled in a Phase I/II study of neoadjuvant chemotherapy followed by concurrent chemotherapy plus radiotherapy with or without subsequent esophagectomy. Patients received one cycle of Cisplatin or Carboplatin plus Etoposide for squamous cell carcinoma, or Cisplatin or Carboplatin plus 5FU for adenocarcinoma, followed by two cycles of the same chemotherapy given concurrently with 44-46 Gy over 5 weeks. Operable patients then underwent esophagectomy. Inoperable patients and those with positive surgical margins received additional irradiation (16-18 Gy). Twelve percent of the surgical group received preoperative radiotherapy doses > or = 50 Gy. Seventy-two percent (103) had clinical Stage I-III tumors and 28% (40) were clinical Stage IV (1983 American Joint Committee on Cancer criteria). Only clinical Stage I-III patients were analyzed with respect to patterns of failure. Isolated local failure occurred in 19/103 (18%) of clinical Stage I-III patients. Both local and distant relapse occurred in 15/103 (15%), and distant metastases alone occurred in 25/103 (24%). The 3-year actuarial rates of local and distant failures were 45% and 60%, respectively. Among the clinical Stage I-III patients who underwent surgery (n = 58) versus those who did not (n = 45), the 3-year actuarial local and distant failure rates were 30% versus 60% and 45% versus 45%, respectively. Multivariate analysis was performed to identify significant predictors of local control. For all clinical Stage I-III patients, treatment with surgery (p = 0.001) and with three or more cycles of chemotherapy (p = 0.02) were significant predictors of improved local control. Patients who underwent surgery were significantly younger and had a better performance status than those who did not. The improvement in local control with surgery did not translate into better survival, likely on account of a high operative mortality rate in older patients and those receiving > or = 50 Gy preoperatively. We conclude that local control remains poor with concurrent chemotherapy + radiotherapy for esophageal cancer. The addition of surgery improved local control, but distant metastases remain a problem both in this group of patients as well as those treated without esophagectomy. Efforts to improve local control appear warranted, but it remains to be demonstrated that improved local control translates into improved survival in esophageal cancer because of a high rate of distant metastases in patients whose disease is controlled in the esophagus.


Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/radioterapia , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/radioterapia , Neoplasias Esofágicas/tratamiento farmacológico , Neoplasias Esofágicas/radioterapia , Esofagectomía , Adenocarcinoma/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Células Escamosas/cirugía , Terapia Combinada/efectos adversos , Neoplasias Esofágicas/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis de Supervivencia , Insuficiencia del Tratamiento
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