RESUMEN
Ultrasonography (US) and Electrical Impedance Tomography (EIT) can be used to detect breast cancer. Ultrasonography is based on non-ionizing radiations without adverse biological effects. A set of electrodes was placed around the torso and a small alternating current (AC) was injected via two of the electrodes into the object. This study aimed to acquire preliminary data to evaluate the EIT method for differentiation of artificial solid and cystic tumors in comparison to standard US. This study used a phantom made from chicken meat. In order to obtain the image of the solid tumor, an olive with carrot insertion was done, and the cystic tumor was created by filling a small balloon with water. GE Logic C5 ultrasound was performed with a 12 MHz linear transducer. For EIT measurement, 16 ECG electrodes and 32 ECG electrodes were placed. Data processing was done using the Graz consensus Reconstruction algorithm for EIT (GREIT) and Newton's One Step Error Reconstructor (NOSER) methods. The artificial solid tumor produced an ultrasound image of an oval, inhomogeneous lesions. The GREIT method with 16 electrodes of artificial solid tumor did not show a match between the reconstructed image and the original object containing 2 anomalies, but a match was found with 32 electrodes. In the NOSER method, both 16 and 32 electrodes showed a match. Ultrasound of the artificial cystic tumor showed an oval, circumscribed, anechoic with posterior enhancement. Both the GREIT and NOSER methods using the artificial cystic tumor showed a match between the reconstructed image and the original object containing two anomalies. EIT has a lower imaging resolution in comparison to ultrasonography, but is progressively maturing as a tool for monitoring and imaging. The solid and cystic anomalies on the phantoms were visualized by the GREIT and NOSER methods except for the solid anomaly with the GREIT 16 electrodes.
RESUMEN
Various concentrations (0.01, 0.03 and 0.05 wt ratios) of graphene oxide (GO) nanosheets were doped into magnesium oxide (MgO) nanostructures using chemical precipitation technique. The objective was to study the effect of GO dopant concentrations on the catalytic and antibacterial behavior of fixed amount of MgO. XRD technique revealed cubic phase of MgO, while its crystalline nature was confirmed through SAED profiles. Functional groups presence and Mg-O (443 cm-1) in fingerprint region was evident with FTIR spectroscopy. Optical properties were recorded via UV-visible spectroscopy with redshift pointing to a decrease in band gap energy from 5.0 to 4.8 eV upon doping. Electron-hole recombination behavior was examined through photoluminescence (PL) spectroscopy. Raman spectra exhibited D band (1338 cm-1) and G band (1598 cm-1) evident to GO doping. Formation of nanostructure with cubic and hexagon morphology was confirmed with TEM, whereas interlayer average d-spacing of 0.23 nm was assessed using HR-TEM. Dopants existence and evaluation of elemental constitution Mg, O were corroborated using EDS technique. Catalytic activity against methyl blue ciprofloxacin (MBCF) was significantly reduced (45%) for higher GO dopant concentration (0.05), whereas bactericidal activity of MgO against E. coli was improved significantly (4.85 mm inhibition zone) upon doping with higher concentration (0.05) of GO, owing to the formation of nanorods.
RESUMEN
We present a case of cerebral Scedosporium apiospermum infection presenting with intestinal manifestations in a 64-year-old male patient on immunosuppression for orthotopic liver transplantation. At admission, the patient's chief complaint was chronic watery diarrhea and he was found to have colonic ulcers on endoscopy. His hospital course was complicated by a tonic-clonic seizure caused by a left frontal brain abscess, with the causative agent being identified by culture. He was treated with lobectomy, high-dose intravenous voriconazole, and liposomal amphotericin with clinical, endoscopic, and histologic improvement. To our knowledge, S. apiospermum has not been previously described as a cause of colitis. The septate branching appearance of the Scedosporium species is similar to the more common Aspergillus species. This case of gastrointestinal Scedosporium brings into question previously reported cases of isolated gastrointestinal aspergillosis diagnosed by histopathology. Clinical suspicion for S. apiospermum must be maintained in immunosuppressed patients presenting with neurologic and gastrointestinal symptoms.
Asunto(s)
Infecciones Fúngicas del Sistema Nervioso Central/complicaciones , Infecciones Fúngicas del Sistema Nervioso Central/diagnóstico , Colitis Ulcerosa/diagnóstico , Colitis Ulcerosa/etiología , Scedosporium/aislamiento & purificación , Anfotericina B/uso terapéutico , Antifúngicos/uso terapéutico , Absceso Encefálico/diagnóstico , Absceso Encefálico/tratamiento farmacológico , Absceso Encefálico/microbiología , Absceso Encefálico/cirugía , Infecciones Fúngicas del Sistema Nervioso Central/microbiología , Infecciones Fúngicas del Sistema Nervioso Central/patología , Colitis Ulcerosa/tratamiento farmacológico , Colitis Ulcerosa/patología , Histocitoquímica , Humanos , Masculino , Microscopía , Persona de Mediana Edad , Psicocirugía , Pirimidinas/uso terapéutico , Triazoles/uso terapéutico , VoriconazolRESUMEN
CONTEXT: Thyroid cancer predominately affects women, carries a worse prognosis in older age, and may have higher mortality in men. Superimposed on these observations is the fact that most women have attained menopause by age 55 yr. OBJECTIVE: The objective of the study was to determine whether men contribute disproportionately to papillary thyroid cancer (PTC) mortality or whether menopause affects PTC prognosis. DESIGN: Gender-specific mortality was normalized using age-matched subjects from the U.S. population. Multivariate Cox proportional hazard regression models incorporating gender, age, and National Thyroid Cancer Treatment Cooperative Study Group stage were used to model disease-specific survival (DSS). PARTICIPANTS AND SETTING: Patients were followed in a prospective registry. MAIN OUTCOME MEASURE: The relationships between gender, age, and PTC outcomes were analyzed. RESULTS: The unadjusted hazard ratio (HR) for DSS for women was 0.40 [confidence interval (CI) 0.24-0.65]. This female advantage diminished when DSS was adjusted for age at diagnosis and stage with a HR encompassing unity (HR 0.72, CI 0.44-1.19). Additional multivariate models of DSS considering gender, disease stage, and various age groupings showed that the DSS for women diagnosed at under 55 yr was improved over men (HR 0.33, CI 0.13-0.81). However, the HR for DSS increased to become similar to men for women diagnosed at 55-69 yr (HR 1.01, CI 0.42-2.37) and at 70 yr or greater (HR 1.17, CI 0.48-2.85). CONCLUSIONS: Although the overall outcome of women with PTC is similar to men, subgroup analysis showed that this composite outcome is composed of two periods with different outcomes. The first period is a period with better outcomes for women than men when the diagnosis occurs at younger than 55 yr; the second is a period with similar outcomes for both women and men diagnosed at ages greater than 55 yr. These data raise the question of whether an older age cutoff would improve current staging systems. We hypothesize that older age modifies the effect of gender on outcomes due to menopause-associated hormonal alterations.
Asunto(s)
Carcinoma Papilar/mortalidad , Sistema de Registros/estadística & datos numéricos , Neoplasias de la Tiroides/mortalidad , Distribución por Edad , Anciano , Estudios de Cohortes , Femenino , Humanos , Longevidad , Masculino , Menopausia , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Grupos Raciales/estadística & datos numéricos , Distribución por Sexo , Estados Unidos/epidemiologíaRESUMEN
Anaplastic thyroid carcinoma (ATC) is the most malignant and aggressive form of thyroid cancer. Most patients die within months of diagnosis, primarily due to the absence of effective chemotherapeutic strategies. Identifying alternative therapies is necessary to increase long-term survival. Butyrate elicits a number of responses from cancer cells both in vitro and in vivo including growth repression, cell cycle arrest, differentiation, and apoptosis. Even though many types of cancer cells have been studied, little is known of the response of ATC cells to this drug. In this study, we report that butyrate induces differential cell cycle arrest (arrest in G1 and G2/M phases) in an ATC cell line that correlates with changes in the expression, phosphorylation, and activity of key components of the cell cycle machinery. Exposure to butyrate increases the expression of the cyclin-dependent kinase inhibitors, p21/Cip1 and p27/Kip1, decreases the expression of cyclin A and cyclin B, inhibits the phosphorylation of the retinoblastoma protein (pRb), and decreases the activity of cdk1 and cdk2-associated kinases. These results suggest that butyrate may be useful in the clinical treatment of ATC.
Asunto(s)
Butiratos/farmacología , Quinasas CDC2-CDC28 , Carcinoma/patología , Proteínas de Ciclo Celular , Ciclo Celular/efectos de los fármacos , Expresión Génica/efectos de los fármacos , Neoplasias de la Tiroides/patología , Proteínas Supresoras de Tumor , Proteína Quinasa CDC2/antagonistas & inhibidores , Ciclina A/genética , Ciclina B/genética , Quinasa 2 Dependiente de la Ciclina , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Inhibidor p27 de las Quinasas Dependientes de la Ciclina , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Ciclinas/genética , Inhibidores Enzimáticos/farmacología , Fase G1/efectos de los fármacos , Fase G2/efectos de los fármacos , Humanos , Proteínas Asociadas a Microtúbulos/genética , Mitosis/efectos de los fármacos , Fosforilación , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteína de Retinoblastoma/metabolismo , Células Tumorales CultivadasRESUMEN
The polyamines, relatively low-molecular-weight aliphatic compounds, are the main inducers of eukaryotic cell growth and proliferation. Although polyamine requirements for cell growth are well defined, their role is still enigmatic. We have previously reported that amyloid beta-peptide (A beta), the main constituent of senile plaques in Alzheimer's disease (AD) brain, is toxic to neurons through a free radical-dependent oxidative stress mechanism and that A beta(1--42), the principal form of A beta in AD brain, causes an increase in polyamine metabolism manifested by up-regulated polyamine uptake and increased ornithine decarboxylase (ODC) activity. Both effects were prevented by the free radical scavenger vitamin E. Spermine has been reported to function directly as a free radical scavenger. In the current study, we aimed to address whether up-regulation of polyamine metabolism is a defense against, or a result of, A beta-induced oxidative stress by investigating the capability of spermine to quench A beta-associated free radicals in solution and to assert a protective function of spermine in neuronal culture against A beta. Pretreatment of cultured neurons with spermine prior to A beta exposure failed to prevent A beta-induced cell death. Indeed, A beta plus spermine added to cultured neurons was even more neurotoxic than either agent alone. Additionally, inhibition of the polyamine synthesis by difluoromethylornithine (DFMO) did not protect cells from A beta-induced free radical toxicity, and stimulation of the synthesis of putrescine and spermine by the aminopropyltransferase inhibitor S-adenosyl-1,8-diamino-thiooctane (AdoDATO), rather, further enhanced A beta-induced toxicity. Although spermine is capable of scavenging free radicals generated by A beta in solution as measured by electron paramagnetic resonance (EPR) spectroscopy, the up-regulated transport of exogenously added spermine together with A beta may lead to overaccumulation of a cellular spermine pool, with resulting enhanced neurotoxicity.
Asunto(s)
Péptidos beta-Amiloides/toxicidad , Depuradores de Radicales Libres/farmacología , Neuronas/efectos de los fármacos , Fragmentos de Péptidos/toxicidad , Espermina/fisiología , Adenosina/análogos & derivados , Adenosina/farmacología , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/síntesis química , Animales , Apoptosis/efectos de los fármacos , Células Cultivadas/efectos de los fármacos , Eflornitina/farmacología , Espectroscopía de Resonancia por Spin del Electrón , Inhibidores Enzimáticos/farmacología , Radicales Libres , Neuronas/metabolismo , Estrés Oxidativo , Fragmentos de Péptidos/síntesis química , Poliaminas/metabolismo , Ratas , Ratas Sprague-Dawley , Espermidina Sintasa/antagonistas & inhibidores , Espermina/farmacologíaRESUMEN
BACKGROUND: The aggressiveness of familial non-medullary thyroid cancer (FNMTC) has been a subject of debate. The purpose of the study was to determine whether FNMTC is more aggressive than sporadic thyroid cancer. METHODS: A multicenter retrospective matched-case control study of FNMTC versus sporadic non-medullary thyroid cancer was conducted. Disease-free survival (time to recurrence) for both groups was compared. RESULTS: Forty-eight familial cases were compared with 144 age-, gender-, and stage-matched controls. Patients with FNMTC had a significantly shorter disease-free survival compared with sporadic non medullary thyroid cancer. Patients with FNMTC who presented with evidence of distant metastasis, or who were from families with more than 2 thyroid cancer-affected members, had the worst prognosis. The available staging systems were less likely to predict the outcome in patients with FNMTC than in patients with sporadic non-medullary thyroid cancer unless one accounted for the strength of family history in the staging system. CONCLUSIONS: FNMTC is more aggressive than sporadic non-medullary thyroid cancer. The best predictors of a poor outcome in patients with FNMTC are the number of family members affected by thyroid cancer and evidence of distant metastasis.
Asunto(s)
Neoplasias de la Tiroides/patología , Adulto , Anciano , Estudios de Casos y Controles , Supervivencia sin Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Neoplasias de la Tiroides/genética , Neoplasias de la Tiroides/cirugía , Tiroidectomía , Resultado del TratamientoRESUMEN
Anaplastic thyroid carcinoma is a rare, lethal disease with no effective systemic therapies. Preclinical studies demonstrated antineoplastic activity of paclitaxel. This prompted a prospective phase 2 clinical trial to determine activity of paclitaxel against anaplastic thyroid carcinoma in patients with persistent or metastatic disease despite surgery or local radiation therapy. Twenty patients, entered through 6 of 12 study sites, were treated with 96-hour continuous infusion paclitaxel every 3 weeks for 1 to 6 cycles; the first 7 patients received 120 mg/m2 per 96 hours and the rest received 140 mg/m2 per 96 hours. Total responses to therapy were assessed using modified criteria with response durability acceptable at 2 or more weeks, due to the exceedingly rapid growth rate of this tumor. Plasma samples were obtained for pharmacokinetic analyses. Off-protocol, data showed that 9 patients were later treated with 225 mg/m2 paclitaxel as weekly 1-hour infusions. Nineteen evaluable patients demonstrated a 53% total response rate (95% confidence interval, 29%-76%) with one complete response and nine partial responses (including one off protocol). Results of historical review off-protocol showed 2 of 7 patients, with prior partial responses to the 96-hour infusion, had subsequent partial responses to weekly treatment and 1 of 2 prior nonresponders gained a partial response to weekly therapy. No toxicities greater than grade 2 were seen with 96-hour infusions, while peripheral neuropathy (up to grade 3) was most common with postprotocol weekly infusions. Paclitaxel appears to be the only agent with significant clinical systemic activity against anaplastic thyroid carcinoma; however, it is not capable of altering the lethality of this malignancy, suggesting the need for additional therapeutic innovations. Decreased time intervals between paclitaxel infusions may be more efficacious.
Asunto(s)
Carcinoma/tratamiento farmacológico , Paclitaxel/uso terapéutico , Neoplasias de la Tiroides/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Paclitaxel/administración & dosificación , Paclitaxel/farmacocinética , Tasa de Supervivencia , Neoplasias de la Tiroides/mortalidad , Neoplasias de la Tiroides/patología , Resultado del TratamientoRESUMEN
OBJECTIVE: To define the optimal approach to identify patients with thyroid dysfunction. PARTICIPANTS: The 8-member Standards of Care Committee of the American Thyroid Association prepared a draft, which was reviewed by the association's 780 members, 50 of whom responded with suggested revisions. EVIDENCE: Relevant published studies were identified through MEDLINE and the association membership's personal resources. CONSENSUS PROCESS: Consensus was reached at group meetings. The first draft was prepared by a single author (P.W.L.) after group discussion. Suggested revisions were incorporated after consideration by the committee. CONCLUSIONS: The American Thyroid Association recommends that adults be screened for thyroid dysfunction by measurement of the serum thyrotropin concentration, beginning at age 35 years and every 5 years thereafter. The indication for screening is particularly compelling in women, but it can also be justified in men as a relatively cost-effective measure in the context of the periodic health examination. Individuals with symptoms and signs potentially attributable to thyroid dysfunction and those with risk factors for its development may require more frequent serum thyrotropin testing.
Asunto(s)
Enfermedades de la Tiroides/diagnóstico , Adulto , Femenino , Humanos , Masculino , Anamnesis/normas , Pruebas de Función de la Tiroides/normas , Estados UnidosAsunto(s)
Neoplasias de la Tiroides , Adenocarcinoma Folicular/patología , Adenocarcinoma Folicular/terapia , Carcinoma/patología , Carcinoma/terapia , Carcinoma Papilar/patología , Carcinoma Papilar/terapia , Células Epiteliales/patología , Hemangioendotelioma Epitelioide/patología , Hemangioendotelioma Epitelioide/terapia , Hemangiosarcoma/patología , Hemangiosarcoma/terapia , Humanos , Linfoma/patología , Linfoma/terapia , Neoplasias de la Tiroides/patología , Neoplasias de la Tiroides/terapiaRESUMEN
Management of thyroid carcinoma relies upon the tumour cells maintaining the differentiated functions that are typical of normal thyroid follicular cells, such as: dependence upon thyrotropin for growth, production of thyroglobulin and effective transport of iodine. Likewise, differentiated thyroid carcinomas often exhibit an auspicious clinical behaviour with a slow rate of growth and low potential for invasion and distant metastasis. These features permit therapy of disseminated tumour, effective follow-up surveillance and the assumption of a good prognosis. As each of these features are lost, the opportunities for both disease status assessment and therapeutic intervention diminish accordingly. A major obstacle is our failure to define effective systemic treatments to replace radioiodine therapy, whose loss is consonant with the loss of iodine transport and retention. The extreme of undifferentiated clinical behaviour is epitomized by anaplastic thyroid carcinoma, a rare, terminally dedifferentiated malignancy that is rapidly and invariably fatal. It is important to be attuned to clinical clues suggesting the presence of dedifferentiated tumour and related prognostic signs. This allows the application of currently limited therapeutic options and defines the need for research to develop new systemic treatments.
Asunto(s)
Carcinoma/terapia , Diferenciación Celular , Neoplasias de la Tiroides/terapia , Antineoplásicos/uso terapéutico , Carcinoma/patología , Carcinoma/fisiopatología , Terapias Complementarias , Humanos , Radioterapia , Glándula Tiroides/patología , Glándula Tiroides/fisiopatología , Neoplasias de la Tiroides/patología , Neoplasias de la Tiroides/fisiopatologíaRESUMEN
Polyamines are essential cellular components for neoplastic transformation and cell proliferation. Antineoplastic efforts that inhibit polyamine synthesis are insufficient to induce cytotoxicity, due to compensatory induction of polyamine transport. Treatment of an anaplastic human thyroid carcinoma cell line (DRO90-1) with a novel polymeric spermine conjugate (polyspermine; PSpm) caused in vitro cytotoxicity and inhibited the growth of xenograft tumors at low concentrations. Similar in vitro antineoplastic effects were noted with two other human anaplastic thyroid carcinoma cell lines. This coincided with inhibition of polyamine uptake and synthetic enzyme activities, with reduced ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAM-DC) but increased spermidine/spermine N1-acetyltransferase (SSAT) activities, as measured in DRO90-1 cells. In subsequent studies using these cells, PSpm was effective in reducing the intracellular levels of all polyamines in vitro, resulting in cytotoxicity that was not reversed by administration of extracellular polyamines. Low-dose PSpm inhibited tumor growth in vivo, but high doses of PSpm potentiated xenograft tumor growth. PSpm degradation products produced with in vivo treatment may be produced that function as substrates for polyamine biosynthesis. These studies suggest that polyamine metabolism inhibition is a viable target for antineoplastic therapy of anaplastic thyroid carcinoma, although the in vivo response to PSpm suggests that this agent will have limited clinical utility.
Asunto(s)
Poliaminas Biogénicas/biosíntesis , Carcinoma/metabolismo , Neoplasias de la Tiroides/metabolismo , Acetiltransferasas/metabolismo , Adenosilmetionina Descarboxilasa/metabolismo , Animales , Transporte Biológico Activo/efectos de los fármacos , Eflornitina/metabolismo , Humanos , Cinética , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Ornitina Descarboxilasa/metabolismo , Trasplante Heterólogo , Células Tumorales CultivadasRESUMEN
To determine whether programmed cell death in thyroid follicular cells can be related to activation of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) pathway, we examined the expression and function of this pathway in primary thyroid follicular cells and a papillary thyroid carcinoma cell line in vitro. Despite the expression of TRAIL receptors death receptor 4 and death receptor 5, purified TRAIL could not induce programmed cell death (PCD) in any of the thyroid follicular cells examined. However, pre-incubation with cycloheximide before TRAIL facilitated the induction of rapid and massive PCD. This suggested that despite the presence of a labile inhibitor of the TRAIL pathway, TRAIL could mediate PCD under appropriate conditions. To determine whether there were sources of TRAIL in the thyroid that could interact with thyroid follicular cell TRAIL receptors, RNase protection assays were used to determine TRAIL mRNA expression. TRAIL message was expressed in intrathyroidal lymphocytes isolated from a patient with thyroiditis, and unexpectedly, thyroid follicular cells themselves could be induced to express abundant TRAIL message in the presence of the inflammatory cytokines interferon gamma, tumor necrosis factor alpha, and interleukin 1beta. Furthermore, the papillary thyroid carcinoma cell line could be induced to kill the TRAIL-sensitive lymphoma cell line BJAB through a TRAIL-dependent mechanism.
Asunto(s)
Apoptosis/fisiología , Receptores del Factor de Necrosis Tumoral/genética , Glándula Tiroides/metabolismo , Citocinas/fisiología , Regulación de la Expresión Génica/fisiología , Humanos , Mediadores de Inflamación/metabolismo , Papiloma/metabolismo , Papiloma/patología , ARN Mensajero/genética , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF , Receptores del Factor de Necrosis Tumoral/fisiología , Glándula Tiroides/citología , Neoplasias de la Tiroides/metabolismo , Neoplasias de la Tiroides/patología , Células Tumorales CultivadasRESUMEN
Disseminated dedifferentiated thyroid epithelial carcinoma, which cannot sufficiently concentrate therapeutic radioiodide, is a terminal disease without any effective systemic treatment or chemotherapy. This is a likely consequence of loss of human sodium-iodide symporter (hNIS) function. We hypothesized that hNIS transcriptional failure in thyroid carcinoma could be consequent to methylation of DNA in critical regulatory regions and could be reversed with chemical demethylation treatment. Analysis of hNIS messenger ribonucleic acid (mRNA) expression in 23 tumor samples revealed that although loss of this expression corresponded to loss of clinical radioiodide uptake, some thyroid carcinomas with hNIS mRNA expression did not concentrate iodide, suggesting additional posttranscriptional mechanisms for loss of hNIS function. In addition, analysis of DNA methylation in CpG-rich regions of the hNIS promoter extending to the first intron failed to define specific methylation patterns associated with transcriptional failure in human thyroid tumor samples. In seven human thyroid carcinoma cell lines lacking hNIS mRNA, treatment with 5-azacytidine or sodium butyrate was able to restore hNIS mRNA expression in four cell lines and iodide transport in two cell lines. Investigation of methylation patterns in these cell lines revealed that successful restoration of hNIS transcription was associated with demethylation of hNIS DNA in the untranslated region within the first exon. This was also associated with restoration of expression of thyroid transcription factor-1. These results suggest a role for DNA methylation in loss of hNIS expression in thyroid carcinomas as well as a potential application for chemical demethylation therapy in restoring responsiveness to therapeutic radioiodide.
Asunto(s)
Proteínas Portadoras/genética , Metilación de ADN , Yoduros/metabolismo , Proteínas de la Membrana/genética , Simportadores , Neoplasias de la Tiroides/genética , Neoplasias de la Tiroides/metabolismo , Adenoma/genética , Adenoma/metabolismo , Antimetabolitos Antineoplásicos/farmacología , Azacitidina/farmacología , Butiratos/farmacología , Carcinoma Papilar/genética , Carcinoma Papilar/metabolismo , ADN/química , Expresión Génica/efectos de los fármacos , Humanos , Regiones Promotoras Genéticas , ARN Mensajero/análisis , Transcripción Genética , Células Tumorales CultivadasRESUMEN
Recent evidence indicates that alterations in brain polyamine metabolism may be critical for nerve cell survival after a free radical initiated neurodegenerative process. It has been shown previously that A beta(1-42) and A beta(25-35) are toxic to neurons through a free radical dependent oxidative mechanism. Treatment of rat embryonic hippocampal neuronal cultures with A beta-peptides increased ornithine decarboxylase (ODC) activity and spermidine uptake, suggesting that oxidative stress upregulates the polyamine mechanism for the repair of free radical damage. Pretreatment of the cells with vitamin E prior to A beta exposure decreased ODC activity and spermidine uptake to control level. This study is the first to demonstrate that A beta treated cells show an increased polyamine metabolism in response to free radical mediated oxidative stress and that the free radical scavenger vitamin E prevents these attenuations. These results are discussed with reference to Alzheimer's disease.
Asunto(s)
Péptidos beta-Amiloides/farmacología , Neuronas/metabolismo , Ornitina Descarboxilasa/metabolismo , Fragmentos de Péptidos/farmacología , Espermidina/metabolismo , Vitamina E/farmacología , Animales , Transporte Biológico/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Espectroscopía de Resonancia por Spin del Electrón , Feto , Radicales Libres/metabolismo , Hipocampo/citología , Hipocampo/metabolismo , Neuronas/citología , Neuronas/efectos de los fármacos , Ratas , Ratas Sprague-DawleyRESUMEN
As lithium inhibits the release of iodine from the thyroid but does not change iodine uptake, it may potentiate 131I therapy of thyroid cancer. The effects of lithium on the accumulation and retention of 131I in metastatic lesions and thyroid remnants were evaluated in 15 patients with differentiated thyroid carcinoma. Two 131I turnover studies were performed while the patients were hypothyroid. One was performed while the patient received lithium; the second served as a control study. From a series of gamma-camera images, it was found that lithium increased 131I retention in 24 of 31 metastatic lesions and in 6 of 7 thyroid remnants. A comparison of 131I retention during lithium with that during the control period showed that the mean increase in the biological or retention half-life was 50% in tumors and 90% in remnants. This increase occurred in at least 1 lesion in each patient and was proportionally greater in lesions with poor 131I retention. When the control biological half life was less than 3 days, lithium prolonged the effective half-life, which combines both biological turnover and isotope decay, in responding metastases by more than 50%. More 131I also accumulated during lithium therapy, probably as a consequence of its effect on iodine release. The increase in the accumulated 131I and the lengthening of the effective half-life combined to increase the estimated 131I radiation dose in metastatic tumor by 2.29 +/- 0.58 (mean +/- SEM) times. These studies suggest that lithium may be a useful adjuvant for 131I therapy of thyroid cancer, augmenting both the accumulation and retention of 131I in lesions.
Asunto(s)
Carcinoma/tratamiento farmacológico , Carcinoma/radioterapia , Radioisótopos de Yodo/uso terapéutico , Litio/uso terapéutico , Neoplasias de la Tiroides/tratamiento farmacológico , Neoplasias de la Tiroides/radioterapia , Adulto , Anciano , Carcinoma/patología , Carcinoma/secundario , Terapia Combinada , Femenino , Semivida , Humanos , Masculino , Persona de Mediana Edad , Dosis de Radiación , Neoplasias de la Tiroides/patología , Neoplasias de la Tiroides/secundarioRESUMEN
Anaplastic thyroid carcinoma is an extremely aggressive solid tumor that resists most therapeutic efforts and is almost always fatal. It typically arises as a terminal dedifferentiation of unrecognized long-standing differentiated thyroid carcinoma. Current chemotherapeutic agents are not capable of consistent beneficial therapeutic responses, although rare patients may gain additional months of survival. Aggressive local tumor control with surgery and external beam radiotherapy may provide palliation and delay eventual death from distant metastatic disease. This disease challenges clinicians and researchers to develop new systemic therapies as well as to aggressively treat differentiated thyroid cancers before they become anaplastic tumors.
Asunto(s)
Carcinoma/terapia , Neoplasias de la Tiroides/terapia , Terapia Combinada , HumanosRESUMEN
BACKGROUND: Treatment of differentiated thyroid cancer has been studied for many years, but the benefits of extensive initial thyroid surgery and the addition of radioiodine therapy or external radiation therapy remain controversial. OBJECTIVE: To determine the relations among extent of surgery, radioiodine therapy, and external radiation therapy in the treatment of high-risk papillary and non-Hürthle-cell follicular thyroid carcinoma. DESIGN: Analysis of data from a multicenter study. SETTING: 14 institutions in the United States and Canada participating in the National Thyroid Cancer Treatment Cooperative Study Registry. PATIENT: 385 patients with high-risk thyroid cancer (303 with papillary carcinoma and 82 with follicular carcinoma). MEASUREMENTS: Death, disease progression, and disease-free survival. RESULTS: Total or near-total thyroidectomy was done in 85.3% of patients with papillary carcinoma and 71.3% of patients with follicular cancer. Overall surgical complication rate was 14.3%. Total or near-total thyroidectomy improved overall survival (risk ratio [RR], 0.37 [95% CI, 0.18 to 0.75]) but not cancer-specific mortality, progression, or disease-free survival in patients with papillary cancer. No effect of extent of surgery was seen in patients with follicular thyroid cancer. Postoperative iodine-131 was given to 85.4% of patients with papillary cancer and 79.3% of patients with follicular cancer. In patients with papillary cancer, radioiodine therapy was associated with improvement in cancer-specific mortality (RR, 0.30 [CI, 0.09 to 0.93 by multivariate analysis only]) and progression (RR, 0.30 [CI, 0.13 to 0.72]). When tall-cell variants were excluded, the effect on outcome was not significant. After radioiodine therapy, patients with follicular thyroid cancer had improvement in overall mortality (RR, 0.17 [CI, 0.06 to 0.47]), cancer-specific mortality (RR, 0.12 [CI, 0.04 to 0.42]), progression (RR, 0.21 [CI, 0.08 to 0.56]), and disease-free survival (RR, 0.29 [CI, 0.08 to 1.01]). External radiation therapy to the neck was given to 18.5% of patients and was not associated with improved survival, lack of progression, or disease-free survival. CONCLUSIONS: This study supports improvement in overall and cancer-specific mortality among patients with papillary and follicular thyroid cancer after postoperative iodine-131 therapy. Radioiodine therapy was also associated with improvement in progression in patients with papillary cancer and improvement in progression and disease-free survival in patients with follicular carcinoma.
Asunto(s)
Adenocarcinoma Folicular/cirugía , Carcinoma Papilar/cirugía , Neoplasias de la Tiroides/cirugía , Adenocarcinoma Folicular/mortalidad , Adenocarcinoma Folicular/radioterapia , Factores de Edad , Carcinoma Papilar/mortalidad , Carcinoma Papilar/radioterapia , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Estudios de Seguimiento , Humanos , Radioisótopos de Yodo/uso terapéutico , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Radioterapia Adyuvante , Factores Sexuales , Neoplasias de la Tiroides/mortalidad , Neoplasias de la Tiroides/radioterapia , Tiroidectomía , Resultado del TratamientoRESUMEN
The ideal therapy for differentiated thyroid cancer is uncertain. Although thyroid hormone treatment is pivotal, the degree of thyrotropin (TSH) suppression that is required to prevent recurrences has not been studied in detail. We have examined the relation of TSH suppression to baseline disease characteristics and to the likelihood of disease progression in a cohort of thyroid cancer patients who have been followed in a multicenter thyroid cancer registry that was established in 1986. The present study describes 617 patients with papillary and 66 patients with follicular thyroid cancer followed annually for a median of 4.5 years (range 1-8.6 years). Cancer staging was assessed using a staging scheme developed and validated by the registry. Cancer status was defined as no residual disease; progressive disease at any follow-up time; or death from thyroid cancer. A mean TSH score was calculated for each patient by averaging all available TSH determinations, where 1 = undetectable TSH; 2 = subnormal TSH; 3 = normal TSH; and 4 = elevated TSH. Patients were also grouped by their TSH scores: group 1: mean TSH score 1.0-1.99; group 2: mean TSH score 2.0-2.99; group 3: mean TSH score 3.0-4.0. The degree of TSH suppression did not differ between papillary and follicular thyroid cancer patients. However, TSH suppression was greater in papillary cancer patients who were initially classified as being at higher risk for recurrence. This was not the case for follicular cancer patients, where TSH suppression was similar for all patients. For all stages of papillary cancer, a Cox proportional hazards model showed that disease stage, patient age, and radioiodine therapy all predicted disease progression, but TSH score category did not. However, TSH score category was an independent predictor of disease progression in high risk patients (p = 0.03), but was no longer significant when radioiodine therapy was included in the model (p = 0.09). There were too few patients with follicular cancer for multivariate analysis. These data suggest that physicians use greater degrees of TSH suppression in higher risk papillary cancer patients. Our data do not support the concept that greater degrees of TSH suppression are required to prevent disease progression in low-risk patients, but this possibility remains in high-risk patients. Additional studies with more patients and longer follow-up may provide the answer to this important question.
Asunto(s)
Adenocarcinoma Folicular/sangre , Carcinoma Papilar/sangre , Tirotropina/sangre , Tiroxina/uso terapéutico , Adenocarcinoma Folicular/tratamiento farmacológico , Adenocarcinoma Folicular/patología , Adulto , Carcinoma Papilar/tratamiento farmacológico , Carcinoma Papilar/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sistema de Registros , Neoplasias de la Tiroides/sangre , Neoplasias de la Tiroides/tratamiento farmacológico , Neoplasias de la Tiroides/patologíaRESUMEN
BACKGROUND: A novel prognostic staging classification encompassing all forms of thyroid carcinoma was created for the National Thyroid Cancer Treatment Cooperative Study (NTCTCS) Registry, with the goal of prospective validation and comparison with other available staging classifications. METHODS: Patient information was recorded prospectively from 14 institutions. Clinicopathologic staging was based on patient age at diagnosis, tumor histology, tumor size, intrathyroidal multifocality, extraglandular invasion, metastases, and tumor differentiation. RESULTS: Between 1987 and 1995, 1607 patients were registered. Approximately 43% of patients were classified as NTCTCS Stage I, 24% Stage II, 24% Stage III, and 9% Stage IV. Patients with follicular carcinoma were more likely to have "high risk" Stage III or IV disease than those with papillary carcinoma. Of 1562 patients for whom censored follow-up was available (median follow-up, 40 months), 78 died of thyroid carcinoma or complications of its treatment. Five-year product-limit patient disease specific survival was 99.8% for Stage I, 100% for Stage II, 91.9% for Stage III, and 48.9% for Stage IV (P < 0.0001). The frequency of remaining disease free also declined significantly with increasing stage (94.3% for Stage I, 93.1%for Stage II, 77.8% for Stage III, and 24.6% for Stage IV). The same patients also were staged applying six previously published classifications as appropriate for their tumor type. The predictive value of the NTCTCS Registry staging classification consistently was among the highest for disease specific mortality and for remaining disease free, regardless of the tumor type. CONCLUSIONS: The NTCTCS Registry staging classification provides a prospectively validated scheme for predicting short term prognosis for patients with thyroid carcinoma.