RESUMO
In fluorescence microscopy imaging, the segmentation of adjacent cell membranes within cell aggregates, multicellular samples, tissue, organs, or whole organisms remains a challenging task. The lipid bilayer is a very thin membrane when compared to the wavelength of photons in the visual spectra. Fluorescent molecules or proteins used for labelling membranes provide a limited signal intensity, and light scattering in combination with sample dynamics during in vivo imaging lead to poor or ambivalent signal patterns that hinder precise localisation of the membrane sheets. In the proximity of cells, membranes approach and distance each other. Here, the presence of membrane protrusions such as blebs; filopodia and lamellipodia; microvilli; or membrane vesicle trafficking, lead to a plurality of signal patterns, and the accurate localisation of two adjacent membranes becomes difficult. Several computational methods for membrane segmentation have been introduced. However, few of them specifically consider the accurate detection of adjacent membranes. In this article we present ALPACA (ALgorithm for Piecewise Adjacent Contour Adjustment), a novel method based on 2D piecewise parametric active contours that allows: (i) a definition of proximity for adjacent contours, (ii) a precise detection of adjacent, nonadjacent, and overlapping contour sections, (iii) the definition of a polyline for an optimised shared contour within adjacent sections and (iv) a solution for connecting adjacent and nonadjacent sections under the constraint of preserving the inherent cell morphology. We show that ALPACA leads to a precise quantification of adjacent and nonadjacent membrane zones in regular hexagons and live image sequences of cells of the parapineal organ during zebrafish embryo development. The algorithm detects and corrects adjacent, nonadjacent, and overlapping contour sections within a selected adjacency distance d, calculates shared contour sections for neighbouring cells with minimum alterations of the contour characteristics, and presents piecewise active contour solutions, preserving the contour shape and the overall cell morphology. ALPACA quantifies adjacent contours and can improve the meshing of 3D surfaces, the determination of forces, or tracking of contours in combination with previously published algorithms. We discuss pitfalls, strengths, and limits of our approach, and present a guideline to take the best decision for varying experimental conditions for in vivo microscopy.
Assuntos
Membrana Celular/ultraestrutura , Extensões da Superfície Celular/ultraestrutura , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Microscopia de Fluorescência/métodos , Algoritmos , Animais , Animais Geneticamente Modificados , Vesículas Citoplasmáticas/ultraestrutura , Embrião não Mamífero , Humanos , Microvilosidades/ultraestrutura , Pseudópodes/ultraestrutura , Peixe-Zebra/embriologiaRESUMO
UNLABELLED: The aim of this study was to determine the frequency of renal abnormalities in HIV positive children hospitalized in one pediatric hospital in Chile. METHOD: a cross sectional study was performed during April 2007. RESULTS: A total of 18 patients were evaluated, ten male and eight female ranging in age from 4 to 19 years. The average age at the time of HIV diagnosis and nephrologic evaluations were 2,69 and 10,7 years respectively. All patients had acquired HIV infection by vertical transmission. Uriñe samples of two children had microalbuminuria; two had monosymptomatic hematuria, and ten had ¿squamous? cells. Hypercalciuria was detected in one patient, renal lithiasis in another and two patients had abnormal renal ultrasonography. All 19 patients had normal blood pressures. Overall 7 patients (39%) had a renal abnormality. CONCLUSIONS: The relatively high incidence of renal abnormalities in our series support the need for a nation-wide screening program to assess the incidence of renal impairment in pediatric HIV positive patients.
Assuntos
Nefropatia Associada a AIDS/diagnóstico , Adolescente , Criança , Pré-Escolar , Chile , Estudos Transversais , Feminino , Hospitais Pediátricos/estatística & dados numéricos , Humanos , Testes de Função Renal , Masculino , Adulto JovemRESUMO
The aim of this study was to determine the frequency of renal abnormalities in HIV positive children hospitalized in one pediatric hospital in Chile. Method: a cross sectional study was performed during April 2007. Results: A total of 18 patients were evaluated, ten male and eight female ranging in age from 4 to 19 years. The average age at the time of HIV diagnosis and nephrologic evaluations were 2,69 and 10,7 years respectively. All patients had acquired HIV infection by vertical transmission. Uriñe samples of two children had microalbuminuria; two had monosymptomatic hematuria, and ten had ¿squamous? cells. Hypercalciuria was detected in one patient, renal lithiasis in another and two patients had abnormal renal ultrasonography. All 19 patients had normal blood pressures. Overall 7 patients (39 percent) had a renal abnormality. Conclusions: The relatively high incidence of renal abnormalities in our series support the need for a nation-wide screening program to assess the incidence of renal impairment in pediatric HIV positive patients.
El objetivo de este estudio fue evaluar la función renal de pacientes infectados con virus de inmuno-deficiencia humana (VIH) que se controlan en un hospital pediátrico chileno. Método: estudio de corte transversal. Resultados: Se evaluaron 18 pacientes, 10 varones y 8 mujeres; edad: entre 4 y 19 años, la edad promedio al diagnóstico de la infección por VIH y al momento de la evaluación fue 2,69 y 10,7 años, respectivamente. Todos nuestros pacientes adquirieron la infección vía vertical. Dos presentaron microalbuminuria y dos hematuria monosintomática. En 10 (55 por ciento) se encontraron células descamativas, en uno hiper-calciuria y en otro litiasis renal. Todos tuvieron presión arterial normal. La ecotomograña renal fue anormal en dos. Se han descrito varias anormalidades renales en pacientes con infección por VIH; en nuestro estudio, 7 pacientes (39 por ciento) tuvieron alteraciones en los exámenes de laboratorio. Conclusión: La alta frecuencia de afectación renal encontrada en pacientes pediátricos con infección por VIH hace necesario plantear un tamizaje nacional para determinar la incidencia de nefropatía asociada en nuestros pacientes.
Assuntos
Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Adulto Jovem , Nefropatia Associada a AIDS/diagnóstico , Chile , Estudos Transversais , Hospitais Pediátricos/estatística & dados numéricos , Testes de Função Renal , Adulto JovemRESUMO
OBJECTIVE: To determine the beta-amyloid precursor protein (betaAPP) isoforms ratio as a risk factor for Alzheimer's Disease and to assess its relationship with demographic and genetic variables of the disease. METHODS: Blood samples from 26 patients fulfilling NINCDS-ADRDA diagnostic criteria for AD and 46 healthy control subjects were collected for Western blotting for betaAPP. A ratio of betaAPP isoforms, in optical densities, between the upper band (130 Kd) and the lower bands (106-110 Kd) was obtained. Odds ratios were obtained to determine risk factor of this component. RESULTS: betaAPP ratio on AD subjects was lower than that of control subjects: 0.3662 +/- 0.1891 vs. 0.6769 +/- 0.1021 (mean +/- SD, p<0.05). A low betaAPP ratio (<0.6) showed an OR of 4.63 (95% CI 1.45-15.33). When onset of disease was taken into account, a betaAPP ratio on EOAD subjects of 0.3965 +/- 0.1916 was found vs. 0.3445 +/- 0.1965 on LOAD subjects (p>0.05). CONCLUSIONS: Altered betaAPP isoforms is a high risk factor for Alzheimer's disease, although it has no influence on the time of onset of the disease.
Assuntos
Doença de Alzheimer/diagnóstico , Precursor de Proteína beta-Amiloide/sangue , Idoso , Alelos , Peptídeos beta-Amiloides/sangue , Apolipoproteínas E/genética , Western Blotting , Diagnóstico Precoce , Feminino , Humanos , Masculino , México , Pessoa de Meia-Idade , Polimorfismo Genético , Isoformas de Proteínas/sangueRESUMO
Para establecer el diagnóstico de tumores de próstata, se deben aplicar tres criterios: epidemiológico, clínico y de laboratorio. Aquí fueron evaluados los dos últimos en hiperplasia* benigna (HBP) y cáncer de próstata (Ca. prostático). Se midió la exactitud del tacto rectal (TR) y del antígeno prostático específico (APE) cmo pruebas para la detección de tumores prostáticos en pacientes del Hospital General de Enfermedades del Instituto Guatemalteco de Seguridad Social (IGSS). Fueron recopilados los datos de 251 pacientes, a quienes se les realizó TR, APE y estudio anatomopatológico durante el 1-1-1994 al 31-12-1997. Los resulados mostraron que el TR es superior al APE como método diagnóstico único para detección de HBP, mientras que para detección de Ca. prostático, el APE fue superior al TR. La importancia del APE radica en la detección precoz del cáncer donde la cirugía ofrece posibilidades de control. La mayor precisión se obtuvo al combinar el TR con el APE. Por lo tanto se recomienda su aplicación combinada para pacientes con sospecha de un tumor prostático, y para tamizar población en riesgo
Assuntos
Humanos , Adulto , Pessoa de Meia-Idade , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/epidemiologiaRESUMO
The hypertrichosis and osteochondrodysplasia syndrome is a rare entity with clinical findings including macrosomia at birth cardiomegaly. Autosomal recessive inheritance is presumed based on the report of two affected sibs born to healthy parents. Here we report on four new patients with their follow-up data, as well as on one of the four cases from the original report. Comparison of all eight cases indicates that they share 50% of clinical and radiological changes. This report contributes to the further delineation of this newly recognized syndrome.
Assuntos
Anormalidades Múltiplas/genética , Cardiomegalia/congênito , Hipertricose/congênito , Osteocondrodisplasias/congênito , Adolescente , Cardiomegalia/diagnóstico , Cardiomegalia/genética , Criança , Pré-Escolar , Feminino , Humanos , Hipertricose/diagnóstico , Hipertricose/genética , Masculino , Osteocondrodisplasias/diagnóstico , Osteocondrodisplasias/diagnóstico por imagem , Osteocondrodisplasias/genética , Fenótipo , Radiografia , Síndrome , Raios XRESUMO
Debido a la alta incidencia de patología del segmento posterior en pacientes con catarata, el ultrasonido actualmente juega un papel muy importante en el estableimiento del pronóstico anatomo-funcional post-extracción de catarata. Decidimos determinar la utilidad de la ultrasonografía como método diagnóstico en estos casos. Se realizó el estudio ecográfico preoperatorio en 106 pacientes con cataratas de etiología variada y se corroboró el diagnóstico clinicamente en el postoperatorio mediato. Obtuvimos un 97.8%de aciertos en los diagnósticos ecográficos lo cual indica un alto índice de confiabilidad en el exámen
Assuntos
Catarata/complicações , Extração de Catarata/efeitos adversos , Ultrassonografia/instrumentação , Catarata/diagnóstico , Catarata/etiologia , Extração de Catarata/métodos , Hemorragia Vítrea/diagnóstico , Descolamento Retiniano/diagnóstico , Hemorragia Retiniana/complicações , Hemorragia Retiniana/diagnósticoRESUMO
The study shows the gasometric and electrolytic features during the first five day from newborns from toxemic mothers. It is a prospective study, carried out during a four month period at the obstetrics premature ward at the Gynecological-Obstetrics Hospital of "La Raza" Medical Center. Thirty-three newborn babies with evidences of toxemia and who had not received any intravenous therapy were studied. Blood samples were taken and serum calcium, phosphorus and magnesium levels were measured at 24, 48, 72 and 120 hours after birth. The results showed that six patients (18%) were anemic, and another had polycythemia. Twelve others (36%) had plaquetopenia, one had hypercalcemia, another hypocalcemia, and eleven (33%) presented hypophosphatemia. Of the initial 33 patients, 75% presented metabolic acidosis which spontaneously corrected itself within the following 72 hours. Three showed signs of hypernatremia, four hyponatremia, and two others hyperkalemia, with a return to normal levels within the next 24 hours. No chloride alterations were found in any of the patients. Some newborn babies born from toxemic mothers can spontaneously correct their electrolytic and acid-base imbalance within 72 hours of their birth. Electrolytes; toxemia.