RESUMO
OBJECTIVES: To evaluate the accuracy of an automated three-dimensional (3D) ultrasound technique for fetal intracranial measurements compared with manual acquisition. METHODS: This was a prospective observational study of patients presenting for routine anatomical survey between 18 + 0 and 22 + 6 weeks' gestation. After providing informed consent, each patient underwent two consecutive ultrasound examinations of the fetal head, one by a sonographer and one by a physician. Each operator obtained manual measurements of the biparietal diameter (BPD), head circumference (HC), transcerebellar diameter (TCD), cisterna magna (CM) and posterior horn of the lateral ventricle (Vp), followed by automated measurements of these structures using an artificial intelligence-based tool, SonoCNS® Fetal Brain. Both operators repeated the automated approach until all five measurements were obtained in a single sweep, up to a maximum of three attempts. The accuracy of automated measurements was compared with that of manual measurements using intraclass correlation coefficients (ICC) by operator type, accounting for patient and ultrasound characteristics. RESULTS: One hundred and forty-three women were enrolled in the study. Median body mass index was 24.0 kg/m2 (interquartile range (IQR), 22.5-26.8 kg/m2 ) and median subcutaneous thickness was 1.6 cm (IQR, 1.3-2.0 cm). Fifteen (10%) patients had at least one prior Cesarean delivery, 17 (12%) had other abdominal surgery and 78 (55%) had an anterior placenta. Successful acquisition of the automated measurements was achieved on the first, second and third attempts in 70%, 22% and 3% of patients, respectively, by sonographers and in 76%, 16% and 3% of cases, respectively, by physicians. The automated algorithm was not able to identify and measure all five structures correctly in six (4%) and seven (5%) patients scanned by the sonographers and physicians, respectively. The ICCs reflected good reliability (0.80-0.88) of the automated compared with the manual approach for BPD and HC and poor to moderate reliability (0.23-0.50) for TCD, CM and Vp. Fetal lie, head position, placental location, maternal subcutaneous thickness and prior Cesarean section were not associated with the success or accuracy of the automated technique. CONCLUSIONS: Automated 3D ultrasound imaging of the fetal head using SonoCNS reliably identified and measured BPD and HC but was less consistent in accurately identifying and measuring TCD, CM and Vp. While these results are encouraging, further optimization of the automated technology is necessary prior to incorporation of the technique into routine sonographic protocols. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.
Assuntos
Biometria/métodos , Feto/diagnóstico por imagem , Cabeça/diagnóstico por imagem , Imageamento Tridimensional/métodos , Ultrassonografia Pré-Natal/métodos , Adulto , Inteligência Artificial , Feminino , Feto/embriologia , Idade Gestacional , Cabeça/embriologia , Humanos , Gravidez , Estudos Prospectivos , Reprodutibilidade dos TestesRESUMO
Willingness to self-collect vaginal swabs at a pharmacy clinic is of interest as a venue to increase sexually transmissible infections (STIs) screening for chlamydia, gonorrhoea and trichomonas. Women self-collected vaginal swabs at the pharmacy, completed questionnaires and received STI results within 2 h. Women with STIs were offered free treatment. A total of 313 of 777 (40.3%) women consented and prevalence for any STI was 3.9%. Questionnaires demonstrated acceptability for self-collection at the pharmacy, with 63% (95% CI 57.3-68) and 32.3% (95% CI 27.4-37.8) indicating they 'strongly agreed' or 'agreed' that they felt comfortable with pharmacy collection, respectively. Self-collected vaginal swabs for STI testing for women who were at a pharmacy were feasible and acceptable to women.
Assuntos
Programas de Rastreamento/métodos , Aceitação pelo Paciente de Cuidados de Saúde , Farmácias , Infecções Sexualmente Transmissíveis/diagnóstico , Esfregaço Vaginal , Adulto , Estudos de Viabilidade , Feminino , Humanos , Pessoa de Meia-Idade , Manejo de Espécimes/métodos , Inquéritos e Questionários , Adulto JovemRESUMO
Treatment for cancer has the potential to significantly diminish fertility and, further, to negatively impact the obstetrical outcomes of pregnancies that do occur. Cancer survivors have decreased rates of fertility and increased rates of pregnancy complications, such as preterm birth and low birth weight, after exposure to chemotherapy. To date, research on the impact of chemotherapy and radiotherapy on fertility and pregnancy outcomes has focused largely on the gonadotoxic effect of cancer treatments on ovaries, while the uterus and endometrium have not been extensively studied. It is intuitive, however, that decreased fertility and poorer obstetrical outcomes may be substantially mediated through injury to a highly mitotic tissue like the endometrium, which is also central to embryo implantation and utero-placental exchange. Pregnancy complications in cancer survivors might be due to compromised blood supply to the endometrium and myometrium affecting placentation or altered remodeling of the pregnant uterus secondary to radiation fibrosis. Alterations in endometrial receptivity at the molecular level could affect pregnancy implantation and early pregnancy loss, but later complications also can occur. This review focuses on understanding the unintended effects of chemotherapy and radiotherapy on uterine function in female cancer survivors and the impact on pregnancy, and summarizes mechanisms to protect and treat the uterus before and after cancer chemotherapy and radiotherapy.
Assuntos
Preservação da Fertilidade , Infertilidade Feminina/terapia , Neoplasias/complicações , Útero/lesões , Endométrio/patologia , Feminino , Humanos , Infertilidade Feminina/induzido quimicamente , Infertilidade Feminina/patologia , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Ovário/patologia , Gravidez , Resultado da Gravidez , Nascimento Prematuro/epidemiologia , Nascimento Prematuro/patologia , Útero/efeitos dos fármacos , Útero/patologiaRESUMO
BACKGROUND: Long-term Hodgkin lymphoma (HL) survivors are known to have diminished quality of life (QoL). However, limited data are available on temporal changes in QoL and factors associated with the changes. METHODS: In 2010, we conducted a follow-up questionnaire study on 273 HL survivors who participated in a 2003 questionnaire study on late effects after HL. The questionnaire items were limited to new late complications and reassessment of QoL and fatigue level, using the Short Form 36 (SF-36) and the Functional Assessment of Chronic Illness Therapy-Fatigue instruments, respectively. We compared the results from the 2003 and the 2010 questionnaires, and QoL score changes between survivors with and without new late complications during the 7-year period. RESULTS: There was a significant decline in the SF-36 Physical Component Summary score (median change, -1.8; P<0.0001) over the time period. The decline was significantly greater among survivors with a new cardiac (P=0.005) or pulmonary (P<0.0001) complication, compared with those without any new complications. The survivors reporting new cardiac complications also experienced significantly greater worsening of fatigue scores (P=0.004). CONCLUSION: The significant association between the development of new cardiopulmonary complications and decline in QoL and energy level of HL survivors provides further support for current efforts to reduce treatment to limit late effects.
Assuntos
Doença de Hodgkin/fisiopatologia , Qualidade de Vida , Sobrevida , Coleta de Dados , Humanos , Estudos LongitudinaisRESUMO
BACKGROUND: Hodgkin lymphoma (HL) survivors have an increased risk of secondary malignancies. We analyzed outcomes in patients with lung cancers following HL treatment. PATIENTS AND METHODS: Cases of thoracic malignancies were retrospectively identified from a multi-institutional database of 1976 patients treated for HL from 1969 to 2007. Data regarding risk factors, disease characteristics and outcomes were obtained from medical records. RESULTS: Lung malignancies were identified in 55 patients a median of 19.5 years after initial HL therapy. Thirty-one patients (56%) had a >10 pack-year history of tobacco use, 48 (87%) received thoracic irradiation and 26 (47%) received alkylating chemotherapy. Of the 42 patients with known stage at lung cancer diagnosis, 23 (55%) were stage IV and 5 (12%) were stage III. The method of lung cancer detection was known for 35 patients; of these, 12 (34%) were detected incidentally. Median survival time after diagnosis was 10 months for all 55 patients. Median survival time for patients with incidentally detected tumors has not been reached with a median follow-up of 39 months. CONCLUSIONS: Lung malignancies diagnosed in patients successfully treated for HL generally have a dismal prognosis. However, a subset of patients diagnosed incidentally may have potentially curable disease.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Doença de Hodgkin/terapia , Neoplasias Pulmonares/diagnóstico , Segunda Neoplasia Primária/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Feminino , Humanos , Achados Incidentais , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Segunda Neoplasia Primária/mortalidade , Estudos Retrospectivos , Adulto JovemRESUMO
BACKGROUND: To assess the efficacy of salvage radiation therapy (RT) in patients with recurrent/refractory primary or secondary central nervous system lymphoma (CNSL) after initial methotrexate (MTX)-based chemotherapy and to identify factors associated with treatment outcome. PATIENTS AND METHODS: We reviewed 36 patients with primary or secondary CNSL who relapsed after MTX therapy and received salvage RT. Primary end points were radiographic response and overall survival (OS). RESULTS: After salvage RT, 18 patients (50%) achieved a complete radiographic response and 6 (17%) achieved a partial response, for an overall response rate of 67% [95% confidence interval (CI) 49% to 81%]. The median OS from start of salvage RT was 11.7 months (range: 0.6-94.7). Patients treated with less than five cycles of MTX before failure had a significantly shorter OS than patients who received five or more cycles (9.2 months versus not reached, P = 0.04). Patients with CNSL limited to brain only had a significantly longer OS than patients with disease in the brain and other central nervous system locations (16.5 versus 4.5 months, P=0.01). CONCLUSION: Salvage RT is effective for patients with recurrent/refractory primary or secondary CNSL after initial MTX therapy. Having received five or more cycles of MTX before failure and CNSL limited to the brain at relapse are associated with longer OS.
Assuntos
Neoplasias do Sistema Nervoso Central/radioterapia , Linfoma/radioterapia , Terapia de Salvação , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Intervalo Livre de Doença , Feminino , Humanos , Linfoma/tratamento farmacológico , Masculino , Metotrexato/uso terapêutico , Recidiva , Estudos Retrospectivos , Resultado do TratamentoRESUMO
BACKGROUND: To prospectively study changes in lung function in Hodgkin's lymphoma (HL) patients and to explore predictors for these changes over time. METHODS: In all, 52 patients with HL receiving bleomycin-based chemotherapy with (n = 23) or without (n = 29) mediastinal radiotherapy were enrolled. Pretreatment pulmonary function tests were carried out. These were repeated at 1 month, 6 months, and 1 year after therapy. RESULTS: With chemotherapy alone, the median %DLCO declined significantly at 1 month but returned to baseline by 6 months. The median %DLCO did not further decrease with radiotherapy, but remained persistently reduced at 1 year. In patients who received radiotherapy, having >33% of lung volume receive 20 Gy (V20) and a mean lung dose (MLD) of >13 Gy significantly predicted for persistently reduced %DLCO at 6 months (P = 0.035). Smoking significantly predicted for a persistently reduced %DLCO at 1 year (P = 0.036). On multivariable analysis, significant predictors for decline in %DLCO at 1 year were higher baseline %DLCO (P = 0.01), higher MLD (P = 0.02), and a smoking history (P = 0.02). CONCLUSIONS: Several factors contribute to decline in %DLCO in HL patients who received bleomycin-based computed tomography. The identification of threshold radiation dosimetric parameters for reduced lung function may provide guidance in the radiation planning of these patients.
Assuntos
Doença de Hodgkin/fisiopatologia , Pneumopatias/etiologia , Pulmão/fisiopatologia , Adolescente , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Bleomicina/administração & dosagem , Terapia Combinada , Feminino , Doença de Hodgkin/tratamento farmacológico , Doença de Hodgkin/radioterapia , Humanos , Pulmão/efeitos dos fármacos , Pulmão/efeitos da radiação , Pneumopatias/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Lesões por Radiação/etiologiaRESUMO
BACKGROUND: The purpose of this study was to analyze response to palliative low-dose involved-field radiotherapy (LD-IF-RT) (two 2-Gy fractions), explore factors predicting for response, and determine the time course to subsequent treatment. PATIENTS AND METHODS: Thirty-three patients with advanced or recurrent indolent non-Hodgkin's lymphoma (NHL) received LD-IF-RT to 43 sites. Response was assessed by physical examination and radiographic studies. Median follow-up for individual sites was 14 months. Fisher's exact test was used to evaluate prognostic factors for response and in-field progression. RESULTS: Overall response was 95%. Thirty-six sites (84%) had a complete response (CR), five sites (12%) had a partial response, and two sites (5%) had progressive disease. The CR rate of head and neck sites was significantly higher than that of pelvic and/or inguinofemoral sites (95% versus 64%, P = 0.04). The CR rate was significantly higher for sites < or =40 mm than for sites >40 mm (90% versus 56%, P = 0.04). Ten sites (23%) had in-field progression diagnosed at a median of 9 months. Sixteen patients (48%) received systemic treatment at a median of 8 months. Fourteen patients (42%) did not require additional treatment. CONCLUSIONS: LD-IF-RT for selected NHL subtypes has excellent local CR and in-field control rates and may postpone the need for systemic therapy.
Assuntos
Linfoma não Hodgkin/radioterapia , Cuidados Paliativos/métodos , Radioterapia/métodos , Adulto , Fatores Etários , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/radioterapia , Prognóstico , Estudos RetrospectivosRESUMO
BACKGROUND AND PURPOSE: Prehospital stroke scales may help identify patients likely to have large-vessel occlusion to facilitate rapid triage to thrombectomy-capable stroke centers. Scale misclassification may result in inaccurate decisions and possible harm. Pre-existing leukoaraiosis has been shown to attenuate the association between deficit type and stroke severity. We sought to determine whether leukoaraiosis affects the predictive ability of 5 commonly used large-vessel occlusion scales. MATERIALS AND METHODS: We retrospectively analyzed 274 consecutive patients with stroke with available brain MR imaging and vessel imaging. We used the following large-vessel occlusion scales: the 3-Item Stroke Scale; Field Assessment Stroke Triage for Emergency Destination; Rapid Arterial Occlusion Evaluation; Vision, Aphasia, Neglect score; and Cincinnati Prehospital Stroke Severity Scale. For diagnostic scale accuracy, we assessed sensitivity, specificity, positive predictive value, negative predictive value, and κ. Multivariable logistic regression was used to determine the predictive ability of the scales after adjustment for leukoaraiosis and potential confounders. RESULTS: In unadjusted analyses, all scales predicted the presence of large-vessel occlusion (n = 46, P < .01 each), though diagnostic accuracy was attenuated among patients with moderate-to-severe leukoaraiosis. After adjustment, the Field Assessment Stroke Triage for Emergency Destination (OR = 3.2; 95% CI, 1.1-9.5; P = .033) and Rapid Arterial Occlusion Evaluation (OR = 3.7; 95% CI, 1.3-10.8; P = .015), but not the 3-Item Stroke Scale (OR = 5.4; 95% CI, 0.86-33.9; P = .073), Vision, Aphasia, Neglect score (OR = 2.5; 95% CI, 0.8-7.2), and Cincinnati Prehospital Stroke Severity Scale (OR = 2.8; 95% CI, 1.0-8.0), predicted large-vessel occlusion. CONCLUSIONS: The diagnostic accuracy of the tested large-vessel occlusion scales was attenuated in the presence of moderate-to-severe leukoaraiosis. This information that may aid the design of future studies that require large-vessel occlusion scale screening of patients who are likely to have concomitant leukoaraiosis.
Assuntos
Leucoaraiose/complicações , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Triagem/métodosRESUMO
BACKGROUND: Solana® (Quidel) is a new rapid (<40 min.) point-of-care (POC) test for qualitative detection of Trichomonas vaginalis (TV) DNA. The assay has two steps: 1) specimen preparation, and 2) amplification and detection using isothermal Helicase-Dependent Amplification (HDA). The objective was to demonstrate the performance of Solana for vaginal swabs and female urines based on comparison to wet mount and TV culture. Performance was also compared to the Aptima-TV assay. METHODS: Urine and four clinician-collected vaginal swabs were collected. The first two were used for FDA composite reference (wet mount; InPouch TV Culture). The third swab was used for Solana. Sensitivity/specificity were based on the reference method. A specimen was considered positive if either test was positive. The fourth swab was for Aptima-TV. RESULTS: Vaginal swabs and urines were obtained from 501 asymptomatic and 543 symptomatic women. Prevalence of TV by was 11.5%. For swabs, Solana® demonstrated high sensitivity and specificity from asymptomatic (100%/98.9%) and symptomatic (98.6%/98.5%) women, as well as for urines from asymptomatic (98.0%/98.4%) and symptomatic (92.9%/97.9%) women, compared to the reference method. Compared to Aptima-TV, the sensitivity/specificity was 89.7%/99.0% for swabs and 100%/98.9% for urines. CONCLUSION: The Solana® assay performed well compared to the reference assays.
Assuntos
Técnicas de Amplificação de Ácido Nucleico , Sistemas Automatizados de Assistência Junto ao Leito , Vaginite por Trichomonas , Trichomonas vaginalis , Adolescente , Adulto , Feminino , Humanos , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Técnicas de Amplificação de Ácido Nucleico/métodos , Sensibilidade e Especificidade , Vaginite por Trichomonas/diagnóstico , Vaginite por Trichomonas/genética , Vaginite por Trichomonas/urina , Esfregaço VaginalRESUMO
BACKGROUND: Previous studies have demonstrated that in patients with coronary artery disease (CAD) upward deflection of the heart rate (HR) performance curve can be observed and that this upward deflection and the degree of the deflection are correlated with a diminished stress dependent left ventricular function. Magnesium supplementation improves endothelial function, exercise tolerance, and exercise induced chest pain in patients with CAD. PURPOSE: We studied the effects of oral magnesium therapy on exercise dependent HR as related to exercise tolerance and resting myocardial function in patients with CAD. METHODS: In a double blind controlled trial, 53 male patients with stable CAD were randomised to either oral magnesium 15 mmol twice daily (n = 28, age 61+/-9 years, height 171+/-7 cm, body weight 79+/-10 kg, previous myocardial infarction, n = 7) or placebo (n = 25, age 58+/-10 years, height 172+/-6 cm, body weight 79+/-10 kg, previous myocardial infarction, n = 6) for 6 months. Maximal oxygen uptake (VO2max), the degree and direction of the deflection of the HR performance curve described as factor k<0 (upward deflection), and the left ventricular ejection fraction (LVEF) were the outcomes measured. RESULTS: Magnesium therapy for 6 months significantly increased intracellular magnesium levels (32.7+/-2.5 v 35.6+/-2.1 mEq/l, p<0.001) compared to placebo (33.1+/-3.1.9 v 33.8+/-2.0 mEq/l, NS), VO2max (28.3+/-6.2 v 30.6+/-7.1 ml/kg/min, p<0.001; 29.3+/-5.4 v 29.6+/-5.2 ml/kg/min, NS), factor k (-0.298+/-0.242 v -0.208+/-0.260, p<0.05; -0.269+/-0.336 v -0.272+/-0.335, NS), and LVEF (58+/-11 v 67+/-10%, p<0.001; 55+/-11 v 54+/-12%, NS). CONCLUSION: The present study supports the intake of oral magnesium and its favourable effects on exercise tolerance and left ventricular function during rest and exercise in stable CAD patients.
Assuntos
Doença da Artéria Coronariana/tratamento farmacológico , Suplementos Nutricionais , Tolerância ao Exercício/efeitos dos fármacos , Exercício Físico/fisiologia , Magnésio/uso terapêutico , Administração Oral , Idoso , Doença da Artéria Coronariana/fisiopatologia , Método Duplo-Cego , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Teste de Esforço , Frequência Cardíaca/efeitos dos fármacos , Humanos , Magnésio/farmacocinética , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio/efeitos dos fármacos , Estudos Prospectivos , Função Ventricular Esquerda/efeitos dos fármacosRESUMO
Recent studies have shown a survival benefit for patients with recurrent glioblastomas treated with stereotactic brachytherapy. On the basis of these encouraging results, we began a prospective study in 1987 to evaluate the use of brachytherapy in patients with newly diagnosed glioblastoma. Patients were considered eligible for this study if they met the following criteria: Karnofsky performance status 70% or greater; tumor size not greater than 5 cm in any dimension; a radiographically well delineated, supratentorial lesion not involving the ependymal surfaces; and pathologically confirmed glioblastoma. We treated 35 such patients between 1987 and 1990 with stereotactic brachytherapy as part of their initial therapy. The treatment protocol involved surgery, partial brain external-beam radiotherapy (59.4 Gy in 33 fractions), and stereotactic brachytherapy with temporary high-activity iodine 125 sources giving an additional 50 Gy to the tumor bed. Chemotherapy was not used in the initial management of these 35 patients. To compare our results with those obtained in a matched control group, we identified 40 patients with glioblastoma treated with surgery and external radiotherapy, with or without chemotherapy, between 1977 and 1986 at our institution. These patients had clinical and radiographic characteristics that would have made them eligible for the brachytherapy protocol. Survival rates at 1 and 2 years after diagnosis were 87% and 57%, respectively, for patients receiving brachytherapy versus 40% and 12.5%, respectively, for the controls (P less than .001). We conclude that stereotactic brachytherapy improves the survival of patients with glioblastoma when it can be incorporated into the initial treatment approach. Unfortunately, only about one in four patients with glioblastoma are suitable candidates for brachytherapy at the time of initial presentation.
Assuntos
Braquiterapia , Glioma/radioterapia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Radioisótopos do Iodo/uso terapêutico , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Análise de SobrevidaRESUMO
We have conducted a clinical trial utilizing anti-thymocyte globulin (ATG) for the treatment of patients with non-Hodgkin's lymphomas. Six patients were treated; 50% reductions in tumor mass of short duration were observed in one patient with a T-cell lymphoma and two patients with B-cell lymphomas. In vitro assays have been performed in an attempt to study the reactivity and potential mechanism of antitumor action of the ATG. The ATG bound to essentially all normal blood mononuclear leukocytes as well as tumor cells from patients with T-, B-, or null cell lymphomas demonstrating its lack of specificity. Furthermore, complement-mediated lysis of normal mononuclear leukocytes, normal T- or B-cells, and tumor cells from two unresponsive patients were all comparable; moreover, since this lysis occurred only at concentrations of ATG that are not attainable in vivo, it is unlikely that complement-mediated cytotoxicity accounts for the responses observed. Peripheral blood lymphocyte counts and total erythrocyte rosettes did decrease during ATG treatment. Thus, objective tumor responses in both B- and T-cell non-Hodgkin's lymphomas can be achieved with a very nonspecific antiserum although significant toxicity resulted. Whether the magnitude or duration of response can be increased with monoclonal antibodies remains to be determined. Future success with serotherapy might require use of either a battery of different monoclonal antibodies or a single monoclonal antibody that can deliver radioisotopes, chemotherapy, or toxins to the tumor cells.
Assuntos
Soro Antilinfocitário/uso terapêutico , Linfoma/terapia , Adolescente , Adulto , Citotoxicidade Celular Dependente de Anticorpos , Linfócitos B/imunologia , Membrana Celular/imunologia , Ensaios Clínicos como Assunto , Feminino , Imunofluorescência , Seguimentos , Humanos , Imunoglobulinas/análise , Linfoma/imunologia , Masculino , Pessoa de Meia-Idade , Neutrófilos/imunologia , Linfócitos T/imunologiaRESUMO
A novel spectroscopic method is described for following the kinetics of resealing of hemolysed erythrocyte ghosts. The procedure is based on the broadening of the EPR spectrum of nitroxyl radicals by paramagnetic ions. The method is used to study the effect of Ca2+, Mg2+ and dimethonium ion on the kinetics of resealing.
Assuntos
Espectroscopia de Ressonância de Spin Eletrônica/métodos , Membrana Eritrocítica/fisiologia , Compostos de Bis-Trimetilamônio/farmacologia , Cálcio/farmacologia , Humanos , Cinética , Magnésio/farmacologiaRESUMO
The hydrophobic interaction between spin-labelled stearic acid and spectrin was studied by electron paramagnetic resonance (EPR) and fluorescence quenching. The results are quantitatively interpreted in terms of two types of binding site on spectrin. A comparison between the results of the EPR and fluorescence experiments show the drawback of the fluorescence method in binding studies.
Assuntos
Espectrina/metabolismo , Ácidos Esteáricos/metabolismo , Sítios de Ligação , Espectroscopia de Ressonância de Spin Eletrônica , Fluorescência , Água/metabolismoRESUMO
Evidence is presented that electrostatic forces play a major role in the interaction between the cell membrane and cytoskeleton of human erythrocytes. Experiments were carried out on the effects of ionic strength variation, Ca2+ and Mg2+ ions, dimethonium ion and lipophilic ions on the release of spectrin from the erythrocyte ghost. In addition it was shown that the release of spectrin for fixed Ca2+ or Mg2+ concentration shows a maximum as a function of Na+ concentration. All results are consistent with the existence of a repulsive electrostatic force between membrane and cytoskeleton.
Assuntos
Citoesqueleto/metabolismo , Membrana Eritrocítica/metabolismo , Eritrócitos/metabolismo , Aspirina/farmacologia , Compostos de Bis-Trimetilamônio/metabolismo , Cálcio/metabolismo , Cloretos/metabolismo , Eletroquímica , Humanos , Iodo/metabolismo , Magnésio/metabolismo , Sódio/metabolismo , Espectrina/metabolismoRESUMO
Sonicated vesicles of 20-50 nm in diameter consisting of neutral phospholipids and a variety of acidic phospholipids were interacted with polylysine, cytochrome c, Ca2+ and Mg2+. The addition of polycations caused massive aggregation accompanied by an increase of membrane permeability as determined by leakage of fluorescent dye. Aggregation was followed by fusion of the vesicles into structures that in some cases exceeded 1 micron in diameter. Polylysine induced aggregation and appreciable fusion at charge ratios (polylysine/phospholipid) of 0.5-2, while divalent cations did so only at charge ratios (cation/phospholipid) greater than 10. Aggregation and fusion induced by polylysine were dependent also on the size of the polycation, i.e., the longer the molecule the less needed to induce similar aggregation. It appears that, due to the concentration of charges on a single molecule, polylysine is at least an order of magnitude more effective than divalent cations at inducing fusion of membranes. Cytochrome c induced fusion of similar vesicles at moderately acidic pH (pH 4.2).
Assuntos
Grupo dos Citocromos c , Lipossomos , Peptídeos , Polilisina , Cálcio , Espectroscopia de Ressonância de Spin Eletrônica , Cinética , Lisofosfatidilcolinas , Magnésio , Ácidos Fosfatídicos , Fosfatidilcolinas , Fosfatidiletanolaminas , Fosfatidilgliceróis , Fosfatidilserinas , Ligação Proteica , Relação Estrutura-AtividadeRESUMO
BACKGROUND: Magnesium blocks many of the physiological actions of calcium. Nevertheless, the impact of magnesium supplementation on endothelial function and exercise tolerance in stable coronary artery disease (CAD) patients has not been assessed. METHODS AND RESULTS: In a randomized, double-blind, placebo-controlled trial, 50 stable CAD patients (41 men and 9 women, mean+/-SD age 67+/-11 years, age range 42 to 82 years) were randomized to receive either magnesium (n=25) (30 mmol/d Magnosolv-Granulat; Asta Medica Company, Inc) or placebo (n=25) for 6 months. Before and after 6 months, endothelium-dependent brachial artery flow-mediated vasodilation (FMD) and endothelium-independent NTG-mediated vasodilation were assessed with high-resolution (10-MHz) ultrasound. Exercise stress testing was performed with use of the Bruce protocol. Intracellular magnesium concentrations ([Mg(2+)](i)) were assessed from sublingual cells through x-ray dispersion (EXA) (normal mean+/-SD values 37. 9+/-4.0 mEq/L). The magnesium therapy significantly increased postintervention ([Mg(2+)](i) versus placebo (36.2+/-5.0 versus 32.7+/-2.7 mEq/L, P<0.02). There was a significant correlation in the total population between baseline [Mg(2+)](i) and baseline FMD (r=0. 48, P<0.01). The magnesium intervention resulted in a significant improvement in postintervention FMD (15.5+/-12.0%, P=0.02 compared with baseline), which was not evident with placebo (4.4+/-2.5%, P=0.78 compared with baseline). There was better exercise tolerance (9.3+/-2.0 versus 7.3+/-3.1 minutes, P=0.05) and less ischemic ST-segment changes (4 versus 10 patients, P=0.05) in the magnesium versus placebo groups, respectively. CONCLUSIONS: Oral magnesium therapy in CAD patients is associated with significant improvement in brachial artery endothelial function and exercise tolerance, suggesting a potential mechanism by which magnesium could beneficially alter outcomes in CAD patients.
Assuntos
Doença das Coronárias/tratamento farmacológico , Magnésio/uso terapêutico , Administração Oral , Adulto , Idoso , Artéria Braquial/efeitos dos fármacos , Artéria Braquial/fisiologia , Método Duplo-Cego , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Tolerância ao Exercício/efeitos dos fármacos , Tolerância ao Exercício/fisiologia , Feminino , Humanos , Magnésio/farmacologia , Masculino , Pessoa de Meia-Idade , Placebos , Resultado do Tratamento , Vasodilatação/efeitos dos fármacosRESUMO
Previous studies of patients with infiltrating ductal breast cancer treated with conservative surgery (ie, limited excision) and radiotherapy have indicated that the presence of an extensive intraductal component (EIC) in the excision specimen is highly associated with subsequent breast recurrence. The reason for this association is not clear, but possible explanations include the presence of more extensive disease in the breast or increased radiation resistance among tumors with an EIC (EIC+) compared with those without (EIC-) tumors. To investigate this association further, we related the presence or absence of an EIC in the primary tumors of 214 women who underwent mastectomy to the likelihood of finding additional foci of cancer in their mastectomy specimens using a correlated pathologic-radiologic mapping technique. Primary tumors that were EIC+ were significantly more likely to have carcinoma in the remainder of the breast than those which were EIC--(74% v 42%; P = .00001). This difference was primarily due to the presence of residual intraductal carcinoma. Seventy-one percent of EIC+ patients had residual intraductal carcinoma compared with 28% of EIC-patients (P less than .00001). In particular, 44% of EIC+ patients had "prominent" residual intraductal carcinoma compared with 3% of EIC-patients (P less than .00001). We conclude that patients whose tumors contain an EIC more frequently have a large subclinical tumor burden in the remainder of the breast compared with patients whose tumors do not contain an EIC. This observation may explain the association between EIC and subsequent breast recurrence when patients are treated with a limited excision before radiotherapy.
Assuntos
Neoplasias da Mama/patologia , Carcinoma Intraductal não Infiltrante/patologia , Mastectomia Segmentar , Recidiva Local de Neoplasia/patologia , Mama/patologia , Neoplasias da Mama/terapia , Carcinoma Intraductal não Infiltrante/terapia , Terapia Combinada , Feminino , Humanos , Invasividade Neoplásica/patologia , Recidiva Local de Neoplasia/etiologia , Período Pós-Operatório , RadioterapiaRESUMO
A total of 315 pathologically staged (PS) patients with IA and IIA Hodgkin's disease (HD) were treated with mantle and paraaortic irradiation, and evaluated for freedom-from-first relapse (FFR), survival, prognostic factors, and long-term complications. The 14-year actuarial FFR and survival were 82% and 93%, respectively, with a median follow-up time of 9 years. Mediastinal size was the only factor that predicted for a lower FFR, P less than .001. Forty-nine patients have developed recurrent HD. Thirty-six patients are disease-free following retreatment and only 13 patients have died of HD. Patients with mixed cellularity (MC) histology were more likely to relapse below the diaphragm (11%) as compared with patients with nodular sclerosis (NS) (5.1%) or lymphocyte predominant (LP) (3.6%) histology. These relapses were often associated with bulky pelvic nodal adenopathy and salvage treatment with chemotherapy alone often failed to control recurrent disease. Alternative diagnostic and therapeutic recommendations are presented for these patients. Thyroid abnormalities represented the most common long-term complication with an actuarial risk at 16 years of 37%. Major complications were rare. Mantle and paraaortic irradiation is associated with a high FFR and a low risk of complications and should remain standard treatment for early-stage HD.