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1.
Pediatr Transplant ; 28(1): e14649, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38013204

RESUMEN

BACKGROUND: Recent studies demonstrate high offer decline and organ non-utilization rates are associated with increased pediatric heart transplant waitlist mortality. We sought to determine which donor, candidate, and offer specific variables most importantly influenced these decisions using only data available at the time of each offer. METHODS: Retrospective review of pediatric (<18 years) heart donor offers made to pediatric candidates in the United States between 2010 and 2020. In addition to standard donor, candidate, and offer data available in UNOS, we extracted objective and qualitative valvar and myocardial function data from all available donor echocardiogram reports. RESULTS: During the study period, 5625 pediatric donor hearts produced 30 156 offers to 4905 unique candidates, of which 88.7% of all offers were declined and 39.2% of organs were not utilized by pediatric waitlisted candidates. Of the 60.8% utilized hearts, 89.7% had a 'cumulatively' normal echocardiogram at the time of offer acceptance; 62.9% of hearts not utilized for a pediatric candidate also had a cumulatively normal final echocardiogram. Random forest and logistic regression modeling demonstrated good predictive performance (AUROC ≥0.83) of likelihood to accept when utilizing donor, candidate, and offer specific variables. SHAP variable importance scores demonstrated number of prior offer declines and candidate institution's prior year acceptance rates as the two most important variables influencing offer decisions. CONCLUSIONS: Behavioral economics appear to play a significant role in pediatric heart transplant candidate institutions' acceptance practices, even when considering the arguably healthier pediatric donor population. Removal of prior institution's decisions from DonorNet may help increase donor utilization.


Asunto(s)
Trasplante de Corazón , Obtención de Tejidos y Órganos , Humanos , Niño , Estados Unidos , Donantes de Tejidos , Selección de Donante , Estudios Retrospectivos , Listas de Espera
2.
Intern Med J ; 45(1): 32-9, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25266859

RESUMEN

BACKGROUND: Previous studies have documented the prevalence of abdominal aortic aneurysm (AAA) during transthoracic echocardiography, but the effect of such screening on subsequent vascular interventions remains unclear. AIM: This study aimed to determine the utility of opportunistic selective screening for AAA in a contemporary large series of patients having transthoracic echocardiography. METHODS: Subjects aged 50 years or older having transthoracic echocardiography had scanning of the infrarenal aorta in a consecutive series of 10 403 men and women. RESULTS: The study subjects had a mean age of 70.2 ± 10.7 years, and 54.1% were men. There was a 3.5% (95% confidence interval (CI) 3.2-3.9%) prevalence of AAA with a median diameter of 39 mm (interquartile range 32 mm-48 mm). In males ≥ 65 years the prevalence of newly diagnosed AAA was 6.2% (95% CI 5.5-7.0%). Of those with newly diagnosed AAA, 39.7% underwent AAA repair. Age and male gender were associated with AAA prevalence. After adjustment for age and gender, echocardiographic variables associated with AAA were left ventricular end diastolic dimension (odds ratio (OR) 1.02, 95%CI 1.01-1.04), interventricular septum thickness (OR 1.11, 95% CI 1.06-1.17), left ventricular posterior wall thickness (OR 1.09, 95% CI 1.03-1.15), left atrial diameter (OR 1.04, 95% CI 1.02-1.07) and aortic root diameter (OR 1.09, 95% CI 1.06-1.11). CONCLUSIONS: This study revealed a high prevalence of newly diagnosed AAA in a group of older men having cardiac evaluation. There was a relationship of increasing age with AAA, and a significant proportion of newly diagnosed subjects were not suitable for AAA repair.


Asunto(s)
Aneurisma de la Aorta Abdominal/epidemiología , Ecocardiografía/métodos , Derivación y Consulta , Anciano , Aneurisma de la Aorta Abdominal/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Nueva Zelanda/epidemiología , Prevalencia , Estudios Retrospectivos , Factores de Riesgo
3.
Ann Oncol ; 21(2): 232-237, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19675093

RESUMEN

BACKGROUND: Previous studies reported that women survive longer than men, but experience greater toxicity, when treated for small-cell lung cancer (SCLC). METHODS: Individual patient data from six randomized phase II/III chemotherapy trials, from the Manchester Lung Group and UK Medical Research Council, were pooled for analysis. End points included overall survival, response rate, toxicity, dose intensity (DI) and transfusion rates. RESULTS: Of 1707 patients analyzed, 44% were women. At baseline, women had poorer performance status (PS) (57% versus 67% Eastern Cooperative Oncology Group PS 0-1/Karnofsky PS 80-100, P = 0.0004) and more were of normal weight or underweight (57% versus 48%, P = 0.003), but fewer were anemic (25% versus 62%, P < 0.0001). Response rates between women and men were similar (77% versus 76%, P = 0.64). In univariate [hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.76-0.96, P = 0.006] and multivariate (HR 0.88, 95% CI 0.79-0.99, P = 0.04) analyses, female sex predicted for longer survival. Women experienced more grade 3/4 emesis (18% versus 9%, P < 0.0001) and grade 3/4 mucositis (13% versus 8%, P = 0.005) than men. There were no differences in DI, infections, transfusions or treatment-related deaths. CONCLUSION: Data from >1700 patients in randomized SCLC chemotherapy trials confirm that women survive modestly longer than men but may experience greater toxicity.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/tratamiento farmacológico , Factores Sexuales , Carcinoma Pulmonar de Células Pequeñas/diagnóstico , Carcinoma Pulmonar de Células Pequeñas/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Ensayos Clínicos como Asunto , Femenino , Humanos , Neoplasias Pulmonares/mortalidad , Masculino , Persona de Mediana Edad , Pronóstico , Carcinoma Pulmonar de Células Pequeñas/mortalidad , Sociedades Médicas , Análisis de Supervivencia , Resultado del Tratamiento , Reino Unido
4.
Science ; 188(4183): 71-2, 1975 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-1078732

RESUMEN

Blastogenic responses in vitro to phytohemagglutinin and pokeweed mitogen were examined in microcultures of peripheral blood lymphocytes from a group of 12 healthy, long-term marihuana smokers and a group of matched control subjects. With either mitogen, no significant difference in cellular incorporation of (3H)thymidine was noted between the groups. These results were interpreted to indicate that the functional status of blood lymphocytes was not altered by long-term smoking of marihuana.


Asunto(s)
Cannabis/farmacología , Activación de Linfocitos/efectos de los fármacos , Adulto , Linfocitos B/inmunología , Femenino , Humanos , Lectinas , Masculino , Lectinas de Plantas , Linfocitos T/inmunología
5.
Bone ; 43(1): 209-213, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18482878

RESUMEN

Mandibular cortical erosion detected on dental panoramic radiographs (DPRs) may be useful for identifying women with osteoporosis, but little is known about the variation in diagnostic efficacy of observers worldwide. The purpose of this study was to measure the accuracy in identifying women at risk for osteoporosis in a worldwide group of observers using DPRs. We constructed a website that included background information about osteoporosis screening and instructions regarding the interpretation of mandibular cortical erosion. DPRs of 100 Japanese postmenopausal women aged 50 years or older who had completed skeletal bone mineral measurements by dual energy X-ray absorptiometry were digitized at 300 dpi. These were displayed on the website and used for the evaluation of diagnostic efficacy. Sixty observers aged 25 to 66 years recruited from 16 countries participated in this study. These observers classified cortical erosion into one of three groups (none, mild to moderate, and severe) on the website via the Internet, twice with an approximately 2-week interval. The diagnostic efficacy of the Osteoporosis Self-Assessment Tool (OST), a simple clinical decision rule based on age and weight, was also calculated and compared with that of cortical erosion. The overall mean sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the 60 observers in identifying women with osteoporosis by cortical erosion on DPRs were 82.5, 46.2, 46.7, and 84.0%, respectively. Those same values by the OST index were 82.9, 43.1, 43.9, and 82.4%, respectively. The intra-observer agreement in classifying cortical erosion on DPRs was sufficient (weighted kappa values>0.6) in 36 (60%) observers. This was significantly increased in observers who specialized in oral radiology (P<0.05). In the 36 observers with sufficient intra-observer agreement, the overall mean sensitivity, specificity, PPV, and NPV in identifying women with osteoporosis by any cortical erosion were 83.5, 48.7, 48.3, and 85.7%, respectively. The mean PPV and NPV were significantly higher in the 36 observers with sufficient intra-observer agreement than in the 24 observers with insufficient intra-observer agreement. Our results reconfirm the efficacy of cortical erosion findings in identifying postmenopausal women at risk for osteoporosis, among observers with sufficient intra-observer agreement. Information gathered from radiographic examination is at least as useful as that gathered from the OST index.


Asunto(s)
Servicios de Salud Dental , Tamizaje Masivo/métodos , Osteoporosis/diagnóstico por imagen , Radiografía Panorámica , Absorciometría de Fotón , Adulto , Anciano , Anciano de 80 o más Años , Densidad Ósea , Femenino , Humanos , Persona de Mediana Edad , Posmenopausia
6.
Radiat Prot Dosimetry ; 129(1-3): 222-6, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18583372

RESUMEN

The image quality of four cone-beam computed tomography (CBCT) scanners dedicated for dentomaxillofacial imaging and one multi-slice computed tomography (MSCT) scanner was compared. For the MSCT scanner, a clinical and a low-dose protocol for oral indications were evaluated. The image quality was assessed by dedicated software that allows an automated analysis of accuracy measurements and evaluation of metal artefacts on two image quality phantoms. Bone was segmented with sub-millimetre accuracyin all scanners.


Asunto(s)
Intensificación de Imagen Radiográfica/métodos , Radiografía Dental/métodos , Radiología/métodos , Tomógrafos Computarizados por Rayos X , Tomografía Computarizada por Rayos X/métodos , Humanos , Dosis de Radiación , Radiografía Dental/instrumentación , Tomografía Computarizada por Rayos X/instrumentación
7.
Asia Pac J Clin Oncol ; 14(6): 410-416, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30270527

RESUMEN

OBJECTIVES: Industry-supported decision impact studies demonstrate that Oncotype Dx (ODX) changes treatment recommendations (TR) in 24-40% of hormone receptor+/HER2- patients. ODX is not reimbursed by third-party payers in Australia, potentially resulting in more selective use. We sought to evaluate the impact of self-funded ODX on TRs. METHODS: Data collected included demographics, tumor characteristics, indication for ODX and pre- and post-recurrence score (RS) TR. Primary endpoint was frequency of TR change and associations with TR change were sought. RESULTS: Eighteen physicians contributed 382 patients (median age 54). A total of 232 (61%) of tumors were T1 and were grade 1, 2 and 3 in 49 (13%), 252 (66%) and 79 (21%). A total of 257 (67%) were node negative. Assay indications were: confirm need for chemotherapy (CT) (36%), confirm omission of CT (40%) and genuine equipoise (24%). RS was low (≤17) in 55%, intermediate (18-31) in 36% and high (≥32) in 9%. Thirty-eight percent of patients had TR change post-ODX. Sixty-five percent of patients recommended CT pre-ODX changed to hormone therapy alone (HT)-more likely if lower grade and if ER and/or PR > 10%. Fourteen percent of patients with pre-ODX TR for HT added CT-more likely if ER and/or PR ≤10% and if Ki67 > 15% Overall, TR for CT decreased from 47% to 24%. CONCLUSION: Patient-funded ODX changed TRs in 38% of patients, de-escalating 65% from CT to HT and adding CT to 14% of those recommended HT. These changes were greater than an industry-funded study suggesting that physicians can identify situations where the assay may influence decisions.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Carcinoma Ductal de Mama/tratamiento farmacológico , Carcinoma Lobular/tratamiento farmacológico , Toma de Decisiones , Perfilación de la Expresión Génica/economía , Pautas de la Práctica en Medicina/normas , Australia , Neoplasias de la Mama/economía , Neoplasias de la Mama/genética , Carcinoma Ductal de Mama/economía , Carcinoma Ductal de Mama/genética , Carcinoma Lobular/economía , Carcinoma Lobular/genética , Quimioterapia Adyuvante , Femenino , Perfilación de la Expresión Génica/métodos , Humanos , Persona de Mediana Edad , Pronóstico
8.
Am Surg ; 72(10): 857-61, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17058721

RESUMEN

In the bariatric surgery literature, the optimum approach to the gallbladder is controversial. Recommendations range from concomitant cholecystectomy to selective screening and postoperative medical prophylaxis. At our institution, we have taken a highly selective approach where patients are not routinely screened for gallstones, nor are they medically treated postoperatively with bile salts. We have reviewed our experience with this approach. From January 2003 to January 2005, 407 laparoscopic Roux en Y gastric bypasses were performed at UCLA and postoperative outcomes were collected into a prospective database. Exclusion criteria included previous cholecystectomy, a follow-up period less than 6 months, or incomplete records. One hundred ninety-nine patients were included in the study. With a mean follow up period of 17.8 months, 12 (6%) patients required cholecystectomy for gallstone-induced pathology. Laparoscopic removal was performed in 11 (92%) patients. Indications for surgery included acute cholecystitis in five (2.5%) patients, gallstone pancreatitis in two (1%) patients, and biliary colic alone in another five (2.5%) patients. The incidence of symptomatic gallstones requiring cholecystectomy after laparoscopic Roux en Y gastric bypass is low. These results are similar to those from institutions where routine preoperative screening and prophylactic postoperative medical therapy is used. Routine preoperative screening or medical prophylaxis may not be necessary.


Asunto(s)
Anastomosis en-Y de Roux/métodos , Ácidos y Sales Biliares/uso terapéutico , Colecistolitiasis/diagnóstico , Derivación Gástrica/métodos , Laparoscopía , Adulto , Anciano , Enfermedades de las Vías Biliares/cirugía , Quimioprevención , Colecistectomía Laparoscópica , Colecistitis/cirugía , Colecistolitiasis/prevención & control , Colecistolitiasis/cirugía , Cólico/cirugía , Femenino , Estudios de Seguimiento , Humanos , Laparoscopía/métodos , Masculino , Persona de Mediana Edad , Pancreatitis/cirugía , Cuidados Posoperatorios , Cuidados Preoperatorios , Estudios Prospectivos , Estudios Retrospectivos , Resultado del Tratamiento
9.
J Natl Cancer Inst ; 80(12): 943-9, 1988 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-3398070

RESUMEN

Findings from this population-based study in Los Angeles County suggest, for the first time, that tumors of the parotid gland are related to prior exposure to diagnostic medical and dental radiography. Responses to interviews with 408 patients with a parotid tumor (269 benign tumors and 139 malignant tumors) were compared to responses of 408 neighborhood controls. Cumulative exposure of the parotid gland from diagnostic radiography was associated with a dose-related increase in risk of malignant tumors (P for trend less than .05; relative risk for exposure to greater than or equal to 50 rad = 3.4; 95% confidence interval = 1.02-11.46). Benign tumors showed a weaker positive association, and exposure before age 20 to a major diagnostic examination (full-mouth or panoramic dental radiography or medical radiography to the head) increased risk (relative risk = 1.8; confidence interval = 1.13-2.91). This study also confirmed the association of malignant tumors with prior radiation treatment to the head or neck; 28% of these tumors are attributable to exposure of the parotid gland from diagnostic and therapeutic radiation.


Asunto(s)
Neoplasias Inducidas por Radiación/etiología , Neoplasias de la Parótida/etiología , Radiografía/efectos adversos , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dosis de Radiación , Radiografía Dental/efectos adversos
10.
Clin Cancer Res ; 6(3): 868-73, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10741709

RESUMEN

This study was designed to assess the activity of oral topotecan (TPT) in patients with advanced non-small cell lung cancer previously untreated with chemotherapy. Eligible patients had inoperable stage III or stage IV non-small cell lung cancer and were chemotherapy-naive. Other inclusion criteria were Eastern Cooperative Oncology Group performance status 0, 1, or 2, adequate bone marrow, and renal and hepatic function. Of 30 patients, 29 were assessable for response. Oral TPT was administered for 5 days every 21 days for up to six cycles unless disease progression or unacceptable toxicity occurred. Patients received a dose of 2.3 mg/m2/day for the first cycle. Dose modification for subsequent cycles was based on tolerability. Patients completed symptom questionnaires every 3 weeks. Pharmacokinetics were evaluated in all patients during cycle 1. Three patients had radiological responses with a reduction in tumor size of 30-40%. No patients achieved complete or partial responses to treatment. Thirteen patients had a stable disease (43.3%), and the median survival was 39.9 weeks with a 1-year survival of 33.3%. At the time of analysis, 27 patients had died. Median time to progression was 12.3 weeks. Treatment was well tolerated. A total of 125 cycles of treatment were completed. Twelve patients (40%) experienced grade III/IV neutropenia. Five patients (16.6%) had grade III/IV anemia. There were two episodes of grade III/IV thrombocytopenia. The main nonhematological toxicities consisted of grade III nausea (13%) and grade III vomiting (13%). The most frequently reported disease-related symptoms at baseline were dyspnea, cough, and fatigue. There was a subsequent improvement in patient scores of dyspnea in 17% of patients, 31% showed improvement in cough, and 32% showed improvement in fatigue. The mean area under the curve of TPT following 2.3 mg/m2 p.o. was 51.6 ng.h/ml (%SD, 25%). The area under the curve of TPT on day 1 of the first cycle was correlated with the percentage fall in leukocytes. Although oral TPT at the applied dose and schedule showed modest activity as a single agent, almost one-half of the patients had a stable disease, and median time to progression was 12.3 weeks. The overall median survival was a promising 39.9 weeks, and useful palliation of symptoms was seen.


Asunto(s)
Antineoplásicos/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Topotecan/uso terapéutico , Administración Oral , Adulto , Anciano , Anciano de 80 o más Años , Alopecia/inducido químicamente , Anemia/inducido químicamente , Antineoplásicos/efectos adversos , Antineoplásicos/farmacocinética , Área Bajo la Curva , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/patología , Femenino , Humanos , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Náusea/inducido químicamente , Estadificación de Neoplasias , Neutropenia/inducido químicamente , Trombocitopenia/inducido químicamente , Topotecan/efectos adversos , Topotecan/farmacocinética , Resultado del Tratamiento , Vómitos/inducido químicamente
11.
Obstet Gynecol ; 48(3): 287-91, 1976 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-948372

RESUMEN

A computerized fetal monitoring system has been developed at the Cedars-Sinai Medical Center in Los Angeles, California. It utilizes unmodified fetal monitors feeding fetal heart rate and uterine pressure data into a minicomputer. The overall accuracy on internal monitoring is 91%. The concept of on-line computer analysis of fetal monitoring records has met with clinical acceptance and is utilized for all patients in labor at the Cedars-Sinai Medical Center.


Asunto(s)
Corazón Fetal/fisiología , Trabajo de Parto , Monitoreo Fisiológico/instrumentación , Presión Sanguínea , Computadores , Computadores Analógicos , Esquema de Medicación , Membranas Extraembrionarias , Femenino , Frecuencia Cardíaca , Humanos , Sistemas de Información , Embarazo , Contracción Uterina , Útero/fisiología
12.
J Dent Res ; 63(6): 910-3, 1984 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-6588078

RESUMEN

Xeroradiographs and Kodak Ektaspeed film were compared with Kodak Ultraspeed film for their ability to reveal periapical lesions. Cadaver specimens containing teeth which were normal or demonstrated periapical inflammatory disease were used as the test objects. These specimens were first radiographed using xeroradiographic plates or film. Following radiography, histologic analysis revealed the true presence or absence of disease. Ten oral radiologists scored all xeroradiographic and film images of the specimens for the presence of periapical disease. In general, the observers detected about 70% of the cases with periapical disease, while simultaneously considering about 10 to 15% of the normal surfaces to be abnormal. Receiver-operating-characteristic (ROC) analysis of the radiographic decisions revealed little difference in the diagnostic performance of the observers using the various image receptors, although both types of film and low-contrast xeroradiographs viewed in transmitted light were all more useful than low-contrast xeroradiographs viewed in reflected light. In terms of patient dose, both xeroradiographic images and Ektaspeed film are preferred over Ultraspeed film.


Asunto(s)
Enfermedades Periapicales/diagnóstico por imagen , Película para Rayos X , Xerorradiografía , Diagnóstico Diferencial , Humanos , Intensificación de Imagen Radiográfica
13.
J Dent Res ; 72(12): 1604-8, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8254130

RESUMEN

Decisions to replace existing restorations are often based on clinical findings of margin discrepancies and other restoration defects. Previous studies have suggested that such findings do not correlate well with the actual presence of secondary caries, and that treatment should be deferred until caries is clinically or radiographically evident. The purpose of this study was to assess the frequency with which clinically defective restorations are associated with radiographic secondary caries. As part of a study to assess the efficacy of guidelines for the ordering of dental radiographs, 6285 restored teeth in 490 subjects were examined clinically and radiographically by three calibrated investigators. Specific criteria were used to determine whether restorations were intact or defective. Of the total, 822 teeth (13%) were judged to have clinically defective restorations. Of these, 113 teeth (14%) had radiographic secondary caries. Of the 5463 teeth with intact restorations, 5% had radiographic secondary caries. We found that the likelihood of radiographic secondary caries was nearly three-fold higher for defective restorations than for intact restorations. The large percentage (86%) of defective restorations with no radiographic secondary caries suggests, however, that replacement of all defective restorations due to risk of secondary caries may constitute overtreatment. The use of defective restoration status and presence of radiographic secondary caries as a combined criterion for replacement may potentially reduce such overtreatment. The prevalence of secondary caries under defective restorations should be determined clinically so that the usefulness of combining the criteria of defective restoration with those of radiographic secondary caries can be evaluated.


Asunto(s)
Caries Dental/diagnóstico por imagen , Restauración Dental Permanente/efectos adversos , Análisis de Varianza , Distribución de Chi-Cuadrado , Resinas Compuestas , Amalgama Dental , Caries Dental/epidemiología , Caries Dental/etiología , Filtración Dental/complicaciones , Filtración Dental/etiología , Porcelana Dental , Restauración Dental Permanente/métodos , Restauración Dental Permanente/normas , Aleaciones de Oro , Humanos , Oportunidad Relativa , Prevalencia , Estudios Prospectivos , Falla de Prótesis , Radiografía , Reoperación , Sensibilidad y Especificidad
14.
J Dent Res ; 81(3): 214-8, 2002 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11876278

RESUMEN

Sickle cell anemia may expand marrow spaces in the jaws. Fourier analysis is well-suited to the analysis of trabecular spacing in radiographs. We hypothesize that individuals with sickle cell anemia demonstrate increased intertrabecular spacing. Periapical radiographs of 18 African Americans with sickle cell disease and 18 controls were examined by one-dimensional discrete Fourier analyses in both jaws for measurement of the spatial frequency distribution of repeating trabecular structures. A strut analysis of trabeculae was also performed and the results compared. Trabecular structures in individuals with sickle cell anemia revealed increased intertrabecular distance compared with controls. Strut analysis revealed significant reductions in trabecular complexity. Fourier analysis allows for the classification of subjects with 94% sensitivity and specificity. Fourier analysis of dental radiographs is a more effective method of identifying individuals with sickle cell anemia than strut analysis.


Asunto(s)
Anemia de Células Falciformes/diagnóstico por imagen , Médula Ósea/diagnóstico por imagen , Análisis de Fourier , Mandíbula/diagnóstico por imagen , Maxilar/diagnóstico por imagen , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Distribución Normal , Valor Predictivo de las Pruebas , Intensificación de Imagen Radiográfica/métodos , Análisis de Regresión , Sensibilidad y Especificidad , Técnica de Sustracción
15.
J Dent Res ; 75(2): 775-82, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8655774

RESUMEN

This study evaluated the replicability of clinical measurements under careful calibration of multiple dentists and how the replicability can relate to their use as selection criteria in guidelines for prescribing dental radiographs. For 48 consenting patients, three dentists clinically examined each patient and recorded the presence of all clinical findings using standardized selection criteria. The examinations were performed independently of each other, but with periodic conferences of the dentists to clarify general measurement criteria. The degree of agreement among the dentists is described by the interrater agreement kappa for several standard clinical indications such as rating of caries, periodontal disease, and tooth mobility. Almost perfect agreement was obtained for tooth status, restoration size, and restoration material. Moderate agreement resulted for measures of caries, defective restoration presence, and gingival recession presence. Only fair agreement was obtained for other periodontal disease measures. The relationship between extent of agreement and guidelines' results was examined for the FDA Guidelines. The differences among the dentists' clinical measurements resulted in considerable differences among the radiographs that were selected by the FDA Guidelines' criteria. Even so, the missed disease rates for 490 patients in a larger study of the FDA Guidelines' efficacy were very low and did not vary greatly among the three dentists. We conclude that guidelines' criteria can be quite robust to variation from dentists' clinical measurement differences, as seen from the FDA Guidelines applied under the idealized setting where the dentists are periodically recalibrated through group discussions of the clinical measurements' definitions and interpretations.


Asunto(s)
Radiografía Dental , Adolescente , Adulto , Calibración , Caries Dental/diagnóstico por imagen , Materiales Dentales , Restauración Dental Permanente , Femenino , Recesión Gingival/diagnóstico por imagen , Gingivitis/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Enfermedades Periodontales/diagnóstico por imagen , Guías de Práctica Clínica como Asunto , Pautas de la Práctica en Medicina , Radiografía de Mordida Lateral , Reproducibilidad de los Resultados , Movilidad Dentaria/diagnóstico por imagen , Estados Unidos , United States Food and Drug Administration
16.
J Dent Res ; 74(7): 1424-32, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7560395

RESUMEN

The diagnosis of periodontitis is generally made on the basis of a clinical examination supported by radiographic evidence of bone loss. Recent guidelines promulgated by the US Food and Drug Administration recommend that periapical radiographs be ordered on the basis of clinical signs and symptoms indicating the probable presence of disease. This study evaluated the effectiveness of the FDA Guidelines for ordering radiographs for new adult dental patients as related to assessment of the periodontal condition of the patient. We examined 490 patients and determined the periapicals needed to supplement the posterior bitewings based upon the patient's clinical findings. We measured the reduction in the number of radiographs ordered as well as the extent of missed alveolar and furcation bone loss resulting from the use of the selected set of radiographs compared with a complete set. Four hundred thirty-three subjects had at least one clinical sign of periodontitis present in their mouths, and 264 demonstrated radiographic evidence of alveolar bone loss. Of the 460 subjects on whom periodontal probing was conducted, two-thirds demonstrated periodontal probing depths in excess of 3 mm; almost half showed evidence of bleeding upon probing. Individuals with clinical signs of periodontitis had, on average, 10 periapicals ordered--more than twice the number as those with no sign of periodontitis. Of the 2,415 teeth with radiographic findings of proximal or furcal bone loss, 152 sites of bone loss (6%) were missed when the selected set of films plus the posterior bitewings was used.


Asunto(s)
Periodoncio/diagnóstico por imagen , Radiografía Dental/normas , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Pérdida de Hueso Alveolar/diagnóstico por imagen , Femenino , Recesión Gingival/diagnóstico por imagen , Gingivitis/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Periodontitis/diagnóstico por imagen , Guías de Práctica Clínica como Asunto , Radiografía Dental/estadística & datos numéricos , Sensibilidad y Especificidad , Estados Unidos , United States Food and Drug Administration
17.
Med Sci Sports Exerc ; 27(1): 8-14, 1995 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7898343

RESUMEN

The purpose of this study was to identify the effects of knee immobilization on uninvolved lower extremity joints during gait. Video and force platform data were collected for seven subjects walking normally (N) and with the knee fixed at three flexion angles: 0 degrees (B00), 10 degrees (B10), and 20 degrees (B20). A bilateral, sagittal plane link-segment model was used to determine lower limb kinematic and kinetic measures. Mean data from three normal and five braced gait trials were compared using one-way repeated measures ANOVA (P < 0.05). Significant increases in involved limb (IL) ankle generation work (J.kg-1) during propulsion were evident: (N = 0.249, B00 = 0.295, B10 = 0.293, B20 = 0.308). There were significant increases in peak IL hip power (W.kg-1) in early stance (N = 0.638, B00 = 1.056, B10 = 1.018, B20 = 1.097) and in IL hip absorption work (J.kg-1) during late stance (N = 0.049, B00 = 0.080, B10 = 0.082, B20 = 0.079). The hip of the uninvolved limb (UL) displayed significant increases in generation work (J.kg-1) in early stance (N = 0.089, B00 = 0.183, B10 = 0.149, B20 = 0.179). Normal kinematic and kinetic patterns of other joints were changed with knee immobilization. The major effects were increases in the magnitude of IL peak hip and ankle joint kinetic measures. Fixing the knee in 10 degrees of flexion resulted in the fewest significant changes in normal gait mechanics.


Asunto(s)
Marcha/fisiología , Inmovilización , Articulación de la Rodilla/fisiología , Pierna/fisiología , Adulto , Articulación del Tobillo/fisiología , Fenómenos Biomecánicos , Tirantes , Femenino , Articulación de la Cadera/fisiología , Humanos , Masculino , Movimiento , Rango del Movimiento Articular , Estrés Mecánico , Grabación en Video , Caminata/fisiología , Trabajo/fisiología
18.
Med Sci Sports Exerc ; 30(10): 1537-42, 1998 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9789855

RESUMEN

PURPOSE: The purpose of this study was to compare vertical ground reaction forces walking overground with vertical foot-belt forces for treadmill gait. METHODS: Twenty-four subjects walked overground and on a treadmill at three speeds (slow, normal, and fast), and at comparable cadences and stride length at each of the speeds. Treadmill and overground vertical force curves were normalized to 100% of stance time and compared using Person's product moment correlation. Selected measures from vertical force records were compared between the two modes of locomotion via repeated measures ANOVA (P < 0.05). Post-hoc analysis consisted of paired t-tests with Bonferroni correction. All comparisons were made across conditions (treadmill vs overground) at each of the three walking speeds. RESULTS: The pattern of reaction forces were similar. Correlation between curves were 0.998, 0.983, and 0.983 for the slow (1.03-1.05 m.s-1), normal (1.40-1.44 m.s-1) and fast (1.65-1.71 m.s-1) walking trials. Small (5-9%) but significant differences in force magnitude for the two forms of locomotion were evident during mid-stance for normal (P = 0.00009) and fast (P = 0.0007) walking speeds and in late stance for normal (P = 0.0014) and fast (P = 0.0005) trials. CONCLUSIONS: Although the patterns of the vertical reaction forces for the two forms of locomotion were nearly identical, small but significant differences in selected force magnitudes were evident. The interpretation of locomotion data collected on a treadmill should consider that forces during mid- and late-stance may be different than if the subject walked overground.


Asunto(s)
Pie/fisiología , Caminata/fisiología , Adulto , Análisis de Varianza , Prueba de Esfuerzo , Femenino , Marcha/fisiología , Humanos , Locomoción/fisiología , Masculino , Procesamiento de Señales Asistido por Computador , Factores de Tiempo , Grabación en Video , Soporte de Peso/fisiología
19.
J Biomech ; 22(8-9): 885-93, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2613724

RESUMEN

Three-dimensional coordinates defining the origin and insertion of 40 muscle units, and bony landmarks for osteometric scaling were identified on dry bone specimens. Interspecimen coordinate differences along the anterior-posterior axis of the pelvis and the long bone axes of the pelvis, femur and leg were reduced by scaling but landmark differences along the other axes were not. The coordinates were mapped to living subjects using close-range photogrammetry to locate superficial reference markers. The error of predicting the positions of internal coordinates was assessed by comparing joint centre locations calculated from local axes defining the orientation of segments superior and inferior to a joint. A difference was attributed to: anatomical variability not accounted for by scaling; errors in identifying and placing reference landmarks; the accuracy of locating markers using photogrammetry and error introduced by marker oscillation during movement. Anatomical differences between specimens are one source of error in defining a musculoskeletal model but larger errors are introduced when such models are mapped to living subjects.


Asunto(s)
Huesos/anatomía & histología , Marcha/fisiología , Articulaciones/anatomía & histología , Pierna , Modelos Anatómicos , Modelos Biológicos , Músculos/anatomía & histología , Antropometría , Huesos/fisiología , Humanos , Articulaciones/fisiología , Músculos/fisiología
20.
J Med Entomol ; 28(6): 872-3, 1991 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1770524

RESUMEN

The blacklegged tick, Ixodes scapularis Say, previously known to occur only in the extreme southeastern corner of Kansas, has been collected in Douglas and Jefferson counties in the northeast. The new collections extend the northern range of this species in Kansas by approximately 240 km. The role of I. scapularis as a vector of the Lyme borreliosis spirochete, Borrelia burgdorferi, makes this a noteworthy extension of its known range. The proximity of these new collection sites to large centers of human population is of special significance to health-care providers in that region.


Asunto(s)
Vectores Arácnidos/fisiología , Enfermedad de Lyme/transmisión , Infestaciones por Garrapatas/epidemiología , Garrapatas/fisiología , Animales , Gatos , Perros , Femenino , Humanos , Kansas/epidemiología , Enfermedad de Lyme/epidemiología , Masculino
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