Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
AJNR Am J Neuroradiol ; 44(10): 1176-1183, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37652584

RESUMEN

BACKGROUND AND PURPOSE: Chondrosarcoma and synovial chondromatosis of the temporomandibular joint share overlapping clinical and histopathologic features. We aimed to identify CT and MR imaging features to differentiate chondrosarcoma from synovial chondromatosis of the temporomandibular joint. MATERIALS AND METHODS: The CT and MR images of 12 and 35 patients with histopathologically confirmed chondrosarcoma and synovial chondromatosis of the temporomandibular joint, respectively, were retrospectively reviewed. Imaging features including lesion size, center, enhancement, destruction/sclerosis of surrounding bone, infiltration into the tendon of the lateral pterygoid muscle, calcification, periosteal reaction, and osteophyte formation were assessed. A comparison between chondrosarcoma and synovial chondromatosis was performed with a Student t test for quantitative variables and the Fisher exact test or linear-by-linear association test for qualitative variables. Receiver operating characteristic analysis was performed to determine the diagnostic performance for differentiation of chondrosarcoma and synovial chondromatosis based on a composite score obtained by assigning 1 point for each of 9 imaging features. RESULTS: High-risk imaging features for chondrosarcoma were the following: lesion centered on the mandibular condyle, destruction of the mandibular condyle, no destruction/sclerosis of the articular eminence/glenoid fossa, infiltration into the tendon of the lateral pterygoid muscle, absent or stippled calcification, periosteal reaction, internal enhancement, and size of ≥30.5 mm. The best cutoff value to discriminate chondrosarcoma from synovial chondromatosis was the presence of any 4 of these high-risk imaging features, with an area under the curve of 0.986 and an accuracy of 95.8%. CONCLUSIONS: CT and MR imaging features can distinguish chondrosarcoma from synovial chondromatosis of the temporomandibular joint with improved diagnostic performance when a subcombination of 9 imaging features is used.

2.
Clin Radiol ; 76(8): 627.e1-627.e11, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33762137

RESUMEN

AIM: To investigate the imaging features of synovial chondromatosis of the temporomandibular joint (TMJ), which is a rare benign arthropathy with cartilaginous proliferation. MATERIALS AND METHODS: Computed tomography and magnetic resonance imaging examinations of 34 patients with histopathologically confirmed primary synovial chondromatosis of the TMJ were reviewed retrospectively. Imaging features including the lesion epicentre, destruction/sclerosis of surrounding bone, calcification, periosteal reaction, osteophyte, lesion size, and joint space dimensions were assessed. RESULTS: Thirty-one of thirty-four patients (91.2%) showed the superior joint space as the lesion epicentre. For the mandibular condyle, more than one-third of patients (14/34; 41.2%) showed no destruction, and more than half of patients (19/34; 55.9%) showed no sclerosis. Conversely, >70% of patients showed destruction and sclerosis of the articular eminence/glenoid fossa, while >80% of patients (28/34; 82.4%) presented with various calcifications, including the ring-and-arc (9/34; 26.5%) and popcorn (13/34; 38.2%) types. The mean joint space on the affected side was significantly larger than that of the unaffected side (p<0.001). More than three-fourths of patients (76.9%) experienced no interval increase in lesion size during an average of 1.6 years of follow-up. CONCLUSION: Synovial chondromatosis of the TMJ demonstrated several imaging features, including the lesion centre being located in the superior joint space, resultant articular eminence/glenoid fossa-oriented bone changes, ring-and-arc and popcorn calcification, joint space widening, and self-limiting growth. These imaging features may be helpful in differentiating synovial chondromatosis from other lesions of the TMJ.


Asunto(s)
Condromatosis Sinovial/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Trastornos de la Articulación Temporomandibular/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Articulación Temporomandibular/diagnóstico por imagen , Adulto Joven
3.
Clin Radiol ; 75(11): 878.e1-878.e12, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32843140

RESUMEN

AIM: To investigate the imaging features of chondrosarcoma of the temporomandibular joint (TMJ) and review the literature. MATERIALS AND METHODS: Computed tomography (CT), magnetic resonance imaging (MRI), and integrated positron-emission tomography (PET)/CT images of nine patients with histopathologically confirmed chondrosarcoma of the TMJ were reviewed retrospectively. Imaging features regarding the direction of lesion growth, bone destruction, infiltration into the tendon of the lateral pterygoid muscle (LPM) in the pterygoid fovea, enhancement pattern, calcification, periosteal reaction, markedly hyperintense T2 signal area, and qualitative PET signal intensity were evaluated. RESULTS: Seven of nine patients (77.8%) presented with lesion growth that was outward from the medulla of the mandibular condyle. Infiltration into the tendon of LPM in the pterygoid fovea was observed in all cases, and 77.8% (7/9) of them demonstrated >50% infiltration. All the lesions showed a mixed peripheral and internal enhancement, and revealed a markedly hyperintense T2 signal intensity area, which showed no enhancement. Although five of nine cases demonstrated higher FDG uptake compared with that of the liver, the other four cases showed less FDG uptake than that of the liver. CONCLUSION: Chondrosarcoma of the TMJ demonstrated several imaging features, including outward growth from the mandibular condyle, resultant infiltration into the tendon of LPM in the pterygoid fovea, various patterns of internal enhancement, and a markedly hyperintense T2 signal intensity area. These imaging features may be helpful to differentiate chondrosarcoma from other lesions of the TMJ.


Asunto(s)
Condrosarcoma/diagnóstico por imagen , Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Trastornos de la Articulación Temporomandibular/diagnóstico por imagen , Articulación Temporomandibular/diagnóstico por imagen , Adolescente , Adulto , Anciano , Femenino , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Tomografía Computarizada por Tomografía de Emisión de Positrones , Músculos Pterigoideos/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adulto Joven
4.
Zhonghua Yi Xue Za Zhi ; 97(43): 3428-3431, 2017 Nov 21.
Artículo en Chino | MEDLINE | ID: mdl-29179286

RESUMEN

Objective: To compare the decolorization efficiency of lignin peroxidase (LiP), manganese peroxidase (MnP) and laccase on eumelanin and pheomelanin, and to investigate the effect of topical administration of LiP solution on hyperpigmented guinea pigs skin induced by 308 nm excimer light. Methods: Pheomelanin-enriched specimens were prepared from human hair and cutaneous melanoma tissue using alkaline lysis method.Synthetic eumelanin was purchased from a commercial supplier.The same amount (0.02%) of melanin was incubated with the equal enzyme activity (0.2 U/ml) of ligninolytic enzymes for 3 h respectively.The absorbance at 475 nm (A(475)) in the enzyme-catalyzed solution was measured using ELISA microplate reader.The experimental hyperpigmentation model was established in the dorsal skin of brownish guinea pigs using 308 nm excimer light radiation.LiP and heat-inactivated LiP solution were topically applied at each site.Meanwhile, 3% hydroquinone and vehicle cream were used as control.The skin color (L value) was recorded using a CR-10 Minolta chromameter.Corneocytes were collected using adhesive taping method.The amount and distribution of melanin in the corneocytes and skin tissues was visualized by Fontana-Masson staining. Results: All three ligninolytic enzymes showed various degree of eumelanin and pheomelanin decolorization activity.The decolorization activity of LiP, MnP and laccase was 40%-70%, 22%-42% and 9%-21%, respectively.The similar lightening was shown in the skin treated with LiP solution and 3% hydroquinone.The amount of melanin granules in the corneocytes was 199±11 by LiP, which was less than that in untreated control (923±12) and heat-inactive control (989±13). The amount of melanin was decreased in the whole epidermis treated with hydroquinone, the epidermis thickness was increased as well. In contrast, melanin of LiP group was decreased only in the superficial epidermis, the epidermis thickness seemed to be normal. Conclusion: LiP exerts a potent decolorization activity for hair- or skin-derived pheomelanin as well as eumelanin.It remains to be further investigated whether LiP serves as a substitute for hydroquinone in skin lightening products.


Asunto(s)
Lacasa/metabolismo , Melaninas/metabolismo , Peroxidasas/metabolismo , Pigmentación , Animales , Epidermis , Cobayas , Cabello , Humanos , Melanoma/enzimología , Piel , Neoplasias Cutáneas/enzimología
5.
Dentomaxillofac Radiol ; 43(7): 20130400, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24940806

RESUMEN

Intraosseous vascular malformation (IVM) is a relatively rare pathological condition that may pose significant risks, such as excessive bleeding, during surgical procedures. We present a case of an 18-year-old female patient with firm swelling in the left maxilla. A bony expansion over the left half of the maxilla with preservation of the outer cortex and a ground glass appearance on CT images initially revealed a possibility of fibrous dysplasia. However, a tentative diagnosis of IVM was made based on the vascular nature of the lesion as well as the patient's surgical history and additional imaging findings. IVM should be included in the differential diagnosis of an expansile bony lesion with trabecular alteration. Through the literature review, it was found that imaging findings, such as a neurovascular canal widening on CT images and a hyperintense signal on T1 weighted MR images, might be helpful in differentiating IVM from other pathologies.

6.
Genet Mol Res ; 12(4): 5640-50, 2013 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-24301933

RESUMEN

Carassius auratus var. Pingxiangnensis (designated CaP), distributed in the Pingxiang region of Jiangxi Province, China, is a natural, wild triploid crucian carp mutant that has two reproductive development modes: gynogenesis and bisexual reproduction. Little information is available about the expression pattern of the zona pellucida 3 (ZP3) gene during ovarian development and the location of the ZP3 protein in oocytes of this fish. In this study, we obtained the full-length cDNA of ZP3 (CaP_ZP3). CaP_ZP3 contains an open reading frame of 1305 bp that encodes 435 amino acid residues. Real-time polymerase chain reaction (PCR) was used to determine the CaP_ZP3 mRNA expression levels in the ovary at different stages of maturation. Results revealed high levels of CaP_ZP3 expression in 4- to 8-month-old ovaries (stage II-stage III), with a significant decline in 9- to 12-month-old ovaries (stages IV-stage V). The high levels of CaP_ ZP3 transcripts during the early growth period suggest an important role for CaP_ZP3 in early oocyte development. In addition, a polyclonal antibody was prepared against CaP_ZP3, and the immunofluorescence localization was determined. CaP_ZP3 protein was detected close to the oocyte plasma membrane. The results also showed that no fluorescent signal was detected in stage I and II oocytes. CaP_ZP3 protein is primarily detected in stage III oocytes, and the protein accumulates as oocytes develop into stage IV oocytes. These results suggested that the transcription and translation of the CaP_ZP3 gene is asynchronous and that the transcription of the CaP_ZP3 protein occurs prior to its translation in this triploid fish.


Asunto(s)
Proteínas del Huevo/metabolismo , Proteínas de Peces/metabolismo , Regulación del Desarrollo de la Expresión Génica , Carpa Dorada/genética , Glicoproteínas de Membrana/metabolismo , Oocitos/metabolismo , Receptores de Superficie Celular/metabolismo , Animales , Proteínas del Huevo/genética , Femenino , Proteínas de Peces/genética , Carpa Dorada/crecimiento & desarrollo , Carpa Dorada/metabolismo , Glicoproteínas de Membrana/genética , Mutación , Oocitos/crecimiento & desarrollo , Oogénesis , Ovario/crecimiento & desarrollo , Ovario/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores de Superficie Celular/genética , Glicoproteínas de la Zona Pelúcida
7.
Dentomaxillofac Radiol ; 42(5): 20100263, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23604054

RESUMEN

Osteoblastoma is a benign neoplasm which commonly occurs in the vertebral column and long bones. The tumour grows slowly and rarely recurs after surgery. This report presents the clinicopathological and radiological findings of a case of recurrent osteoblastoma in the maxilla. A 7-year-old male patient visited our department with chief complaints of left facial swelling and pain. A panoramic radiograph showed a homogeneous radio-opaque expansile lesion in the left maxilla. The lesion was thought to be fibrous dysplasia and the patient underwent a surgical excision using the Caldwell-Luc procedure. Histopathological examination of the lesion confirmed it as benign osteoblastoma. The lesion recurred 6 months after the initial surgery. CT images revealed a large mass with multiple internal calcifications. Subsequently, the patient underwent mass excision with subtotal left maxillectomy. Follow-up CT scans at 1 year intervals showed no recurrence for 5 years.


Asunto(s)
Neoplasias Maxilares/diagnóstico por imagen , Neoplasias Maxilares/patología , Osteoblastoma/diagnóstico por imagen , Osteoblastoma/patología , Niño , Diagnóstico Diferencial , Humanos , Masculino , Recurrencia Local de Neoplasia , Radiografía Panorámica , Tomografía Computarizada por Rayos X
8.
Dentomaxillofac Radiol ; 42(5): 20120172, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23420853

RESUMEN

A dentinogenic ghost cell tumour (DGCT) is an extremely rare odontogenic tumour which is considered as a solid, neoplastic variant of calcifying odontogenic cyst. Intraosseous DGCTs are more aggressive than extraosseous DGCTs and have a high propensity for local recurrence. This report describes a case of a diagnosis of recurrent DGCT at the primary site and a distant donor site. A 25-year-old female patient visited a dental hospital for a complaint of facial swelling for the previous month. Incisional biopsy was performed and the specimen was diagnosed as DGCT. Partial mandibulectomy for tumour resection and iliac bone graft was performed. 2 years later, the tumour recurred on the mandible and iliac bone. The recurrent lesion on the donor site was diagnosed as metastasized DGCT. This report highlights the possibility of distant metastasis occurring at a graft donor site.


Asunto(s)
Neoplasias Óseas/secundario , Ilion/patología , Neoplasias Mandibulares/patología , Tumores Odontogénicos/secundario , Neoplasias Pélvicas/secundario , Sitio Donante de Trasplante/patología , Adulto , Neoplasias Óseas/diagnóstico por imagen , Trasplante Óseo , Femenino , Humanos , Mandíbula/cirugía , Neoplasias Mandibulares/diagnóstico por imagen , Neoplasias Mandibulares/cirugía , Recurrencia Local de Neoplasia , Siembra Neoplásica , Tumores Odontogénicos/diagnóstico por imagen , Neoplasias Pélvicas/diagnóstico por imagen , Radiografía
9.
Dentomaxillofac Radiol ; 41(2): 117-21, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22116134

RESUMEN

OBJECTIVES: This study aimed to show that the horizontal relationship between the mandibular canal and the alveolar crest can influence the available bone height (ABH) measurement on panoramic radiographs. METHODS: 92 mandibular edentulous sites of panoramic computed radiographs and reformatted CT images of 77 patients were used. Selected CT images were categorized into four types according to the relative location of the peak of the alveolar crest to the mandibular canal. One oral and maxillofacial radiologist measured the ABH twice on both imaging modalities with an interval of 7 days and compared the measurement differences according to the type. RESULTS: The absolute average value of the differences in measurement between the values of ABHs on panoramic images and CT images was 0.97 mm. Significant difference was found only between the mean values of ABHs for Type 1 (0.60 mm), where the alveolar crest is located in the buccal side or central area with respect to the mandibular canal, and Type 4 (1.46 mm), where the alveolar crest is in the lingual side to the mandibular canal (p < 0.05). CONCLUSIONS: The relative horizontal location of the alveolar crest with respect to the mandibular canal affected the ABH measurement on panoramic radiographs. In particular, ABH is overestimated when there has been resorption of the buccal aspect of the ridge, moving the alveolar crest lingually.


Asunto(s)
Pérdida de Hueso Alveolar/diagnóstico por imagen , Proceso Alveolar/diagnóstico por imagen , Análisis de Varianza , Artefactos , Implantes Dentales , Humanos , Masculino , Nervio Mandibular/diagnóstico por imagen , Radiografía Panorámica , Estudios Retrospectivos , Tomografía Computarizada por Rayos X
10.
Med Biol Eng Comput ; 41(4): 481-5, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12892373

RESUMEN

Ciliary beating and metachronal waves are fundamental to effective mucociliary transport. The ciliary beat frequencies (CBFs) and metachronal wave directions of multiple cilia beating in culture media were measured simultaneously using digital microscopic images. The degree of synchronisation between ciliary beats was determined by the correlation between ciliary signals at two different locations. The wave propagation directions of cilia were determined from a two-dimensional correlation map by a principal axis method. The standard deviation of measured wave directions in a region of interest was defined as a measure of metachronal wave disorder (MWD). Considerable variation was found in the beat frequencies and metachronal wave directions of cilia beating on epithelium. The pooled mean of MWDs was 23.4 +/- 8.8 degrees, and the pooled mean of CBFs was 10.1 +/- 1.9 Hz on 120 cells from five healthy subjects. The means of the MWD and the CBF from subjects were highly correlated (correlation = -0.83). The higher the CBF, the lower the level of the MWD.


Asunto(s)
Procesamiento de Imagen Asistido por Computador , Depuración Mucociliar , Seno Esfenoidal/fisiología , Humanos , Microscopía por Video , Membrana Mucosa/fisiología
11.
Ann Otol Rhinol Laryngol ; 110(11): 1011-6, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11713910

RESUMEN

This study aimed to determine the characteristics of ciliogenesis and the ciliary beat frequency (CBF) of cultured human nasal epithelial cells by means of an in vitro air-liquid interface (ALI) culture system. On the 14th, 21st, and 27th days of ALI culture, CBFs of cultured cells were measured with a video computerized analysis system, and the epithelial cell-collagen matrix complex was examined by scanning and transmission electron microscopy. Using a CBF distribution map, we calculated the proportion of ciliary beating area (CBA) on the cultured cells. On the 14th day, ciliated cells could be easily distinguished from other cells on scanning electron microscopy by their elongated cilia. Between the 14th and 27th days, the number of mature cilia increased, and after 27 days of air exposure, the cilia of each cell pointed to one direction. From the beginning of air-exposure culture until the 7th day, the number of secretory cells increased; however, from the 7th day to the 27th day, it decreased, and the number of ciliated cells increased. Total CBAs increased from the 7th day to the 21st day. The proportions of actively beating cells and the mean CBFs of beating cells among cultured epithelial cells increased with culture time. On the 21st day, the mean CBF of the cultured cells was similar to that of nasal ciliated cells in biopsy specimens (10.9 +/- 0.5 Hz versus 11.4 +/- 1.3 Hz), but until the 27th day, the CBF of cultured cells increased significantly (13.9 +/- 0.8 Hz). It is suggested that there may be some difference in CBF between nasal epithelial cells submitted to biopsy and nasal epithelial cells cultured by the ALI culture system.


Asunto(s)
Cilios/fisiología , Depuración Mucociliar/fisiología , Mucosa Nasal/citología , Células Cultivadas , Cilios/patología , Células Epiteliales , Humanos , Procesamiento de Imagen Asistido por Computador , Técnicas In Vitro , Microscopía Electrónica de Transmisión de Rastreo , Mucosa Nasal/patología , Estadísticas no Paramétricas , Factores de Tiempo
12.
Otolaryngol Head Neck Surg ; 124(3): 313-6, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11240998

RESUMEN

Various saline solution formulae are frequently used in patients with rhinosinusitis. Osmolarity affects ciliary beat frequency (CBF); however, little is known about the effects of saline solutions on ciliary activity of nasal epithelial cells. The aim of this study was to assess whether CBF of normal turbinate mucosa is affected by hypertonic, isotonic, or hypotonic saline solution in vitro and whether histologic changes are associated with the alteration of ciliary movement. We assessed variations of CBF after exposure to 0.06%, 0.12%, 0.9%, 3.0%, or 7.0% saline solutions and histologic changes were examined by transmission electron microscopy. Isotonic and hypotonic solutions produced no ciliary slowing; however, ciliostasis was observed within a few minutes in 3.0% or 7.0% solution. The histologic changes demonstrated that the ciliary slowing might be attributed to epithelial damage by fluid transport toward the surrounding medium. In conclusion, hypertonic saline solutions decrease CBF and disrupt nasal epithelial cells in vitro.


Asunto(s)
Mucosa Nasal/efectos de los fármacos , Solución Salina Hipertónica/farmacología , Técnicas de Cultivo de Célula , Humanos , Soluciones Hipotónicas/farmacología , Soluciones Isotónicas/farmacología , Masculino , Microscopía Electrónica , Depuración Mucociliar/efectos de los fármacos , Mucosa Nasal/ultraestructura , Factores de Tiempo
13.
Am J Rhinol ; 13(1): 27-30, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10088026

RESUMEN

Previous reports suggested that several cytokines may influence the ciliary beat of the airway ciliated epithelial cells. The aim of this study is to determine the effects of cytokines including IL-1 beta, TNF-alpha, and TGF-beta on ciliary beat frequency (CBF) of human nasal ciliated epithelial cells. CBF of cultured human nasal ciliated epithelial cells was measured 24 hours after incubating with concentrations of 0.01 ng/mL, 0.1 ng/mL, 1 ng/mL, 10 ng/mL, and 100 ng/mL of each recombinant human (rh) cytokine including rhIL-1 beta, rhTNF-alpha, and rhTGF-beta. CBF was measured with time at concentrations of 1 ng/mL of rhIL-1 beta, 10 ng/mL of TNF-alpha, and 1 ng/mL of TGF-beta solutions. CBF of the human nasal ciliated epithelial cells increased after addition of rhIL-1 beta and rhTNF-alpha. Maximum CBF was observed at 1 ng/mL of rhIL-1 beta and at 10 ng/mL of rhTNF-alpha. CBF increased progressively to 4 hours after addition of rhIL-1 beta and rhTNF-alpha. Increased CBF sustained for 24 hours and decreased by 2 days. However, no variation of CBF was observed after addition of rhTGF-beta, regardless of concentrations and time. The results of this study suggest that during acute inflammation, IL-1 beta and TNF-alpha may have a potential role in defense mechanism of human nasal epithelium by regulating CBF of the nasal ciliated epithelial cells.


Asunto(s)
Citocinas/farmacología , Interferón beta/farmacología , Mucosa Nasal/efectos de los fármacos , Factor de Crecimiento Transformador beta/farmacología , Factor de Necrosis Tumoral alfa/farmacología , Adulto , Células Cultivadas , Cilios/efectos de los fármacos , Cilios/fisiología , Células Epiteliales/efectos de los fármacos , Células Epiteliales/fisiología , Humanos , Interferón beta-1a , Interferon beta-1b , Masculino , Mucosa Nasal/fisiología , Proteínas Recombinantes/farmacología , Estimulación Química , Factores de Tiempo , Cornetes Nasales
14.
Stud Health Technol Inform ; 52 Pt 2: 1071-4, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-10384625

RESUMEN

In male reproducible health and fertility and IVF (in-vitro fertilization), morphological analysis of sperm has been most important. But the traditional tools for semen analysis are subjective, imprecise, inaccurate, difficult to standardize, and reproduce mainly due to their manually oriented operations. The purpose of morphological analysis of sperm is to microscopically type-classify sperm according to their morphological characteristics of heads. Until now, the strict criteria method has long been used in clinic to discriminate normal sperm from abnormal. This method cannot classify the diverse groups of abnormal sperm in detail and shows large variations in inter-operators and intra-operator. In this paper, we have studied a new method of sperm morphological classification using artificial neural networks that are widely used in pattern recognition and image processing. With a multi-layer perceptron trained by the error back-propagation algorithm, profile features from digitized sperm images were classified into four classes that consisted of one normal group and three abnormal groups according to their morphological characteristics.


Asunto(s)
Redes Neurales de la Computación , Espermatozoides/clasificación , Espermatozoides/citología , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino
15.
Ann Biomed Eng ; 25(2): 294-302, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9084835

RESUMEN

A new method based on the Hough transform has been used for the quantitative estimation of the morphological characteristics of the sperm. Images of the sperms were acquired into the digital format using the optical microscope, CCD camera, and frame grabber. For each sperm in the image, the region of interest for the segmentation of the sperm head was selected using the density difference between the sperm head and background. The boundary of the sperm head was approximated with an ellipse and represented by five parameters. These five parameters representing an ellipse have been investigated by applying the Hough transform strategically. During the searching procedure using the Hough transform, we restricted the searching volume minimally and moved the next searching volume to the direction showing the steepest gradient of the estimation error. Also, we increased the parameter resolution from the three pixel distance to the one pixel distance. For the tested images, head boundaries of the sperms were estimated with an error of 1/2 pixel distance, and morphological parameters were calculated by the equations without further image processing. This new method separates sperm head based on the geometrical characteristic of the sperm and calculates morphological parameters simply from the derived boundary.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Espermatozoides/citología , Algoritmos , Humanos , Citometría de Imagen/métodos , Citometría de Imagen/normas , Procesamiento de Imagen Asistido por Computador/normas , Procesamiento de Imagen Asistido por Computador/estadística & datos numéricos , Masculino , Matemática , Microscopía por Video/métodos , Modelos Teóricos
16.
Med Biol Eng Comput ; 35(6): 595-9, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9538534

RESUMEN

Through their rapid periodic actions, the cilia of the human respiratory tract play an important role in clearing inhaled noxious particles. An automated method is developed, based on an image-processing technique, to measure and analyse objectively and quantitatively, ciliary beat frequency (CBF). Microscopic ciliary images are transformed into digitised grey images through an image grabber inside a PC, and signals are extracted from these, based on an image-subtraction algorithm, and are processed through power spectrum analysis using a fast Fourier transform (FFT). By means of the FFT power spectrum, maximum peak frequencies are detected as CBFs in each partitioned block for the entire digitised field. Using these CBFs, distribution maps are composed in various resolutions, showing visually the spatial distribution of CBFs through cells and in a single cell. To measure CBF variations quantitatively, phenylephrine hydrochloride is used, and the changes in CBF influenced by its concentration and duration are observed.


Asunto(s)
Células Epiteliales/fisiología , Procesamiento de Imagen Asistido por Computador , Mucosa Nasal/citología , Técnicas de Cultivo de Célula , Cilios/fisiología , Humanos , Fenilefrina
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA