Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
1.
J Dent Res ; 101(1): 102-110, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34157887

RESUMEN

Tooth extraction triggers alveolar ridge resorption, and when this resorption is extensive, it can complicate subsequent reconstructive procedures that use dental implants. Clinical data demonstrate that the most significant dimensional changes in the ridge occur soon after tooth extraction. Here, we sought to understand whether a correlation existed between the rate at which an extraction socket heals and the extent of alveolar ridge resorption. Maxillary molars were extracted from young and osteoporotic rodents, and quantitative micro-computed tomographic imaging, histology, and immunohistochemistry were used to simultaneously follow socket repair and alveolar ridge resorption. Extraction sockets rapidly filled with new bone via the proliferation and differentiation of Wnt-responsive osteoprogenitor cells and their progeny. At the same time that new bone was being deposited in the socket, tartrate-resistant acid phosphatase-expressing osteoclasts were resorbing the ridge. Significantly faster socket repair in young animals was associated with significantly more Wnt-responsive osteoprogenitor cells and their progeny as compared with osteoporotic animals. Delivery of WNT3A to the extraction sockets of osteoporotic animals restored the number of Wnt-responsive cells and their progeny back to levels seen in young healthy animals and accelerated socket repair in osteoporotic animals back to rates seen in the young. In cases where the extraction socket was treated with WNT3A, alveolar ridge resorption was significantly reduced. These data demonstrate a causal link between enhancing socket repair via WNT3A and preserving alveolar ridge dimensions following tooth extraction.


Asunto(s)
Pérdida de Hueso Alveolar , Aumento de la Cresta Alveolar , Pérdida de Hueso Alveolar/diagnóstico por imagen , Pérdida de Hueso Alveolar/cirugía , Proceso Alveolar/diagnóstico por imagen , Proceso Alveolar/cirugía , Animales , Diente Molar/diagnóstico por imagen , Diente Molar/cirugía , Extracción Dental/efectos adversos , Alveolo Dental/cirugía
2.
Med Image Comput Comput Assist Interv ; 12265: 25-35, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33313603

RESUMEN

A major challenge in clinical In-Vitro Fertilization (IVF) is selecting the highest quality embryo to transfer to the patient in the hopes of achieving a pregnancy. Time-lapse microscopy provides clinicians with a wealth of information for selecting embryos. However, the resulting movies of embryos are currently analyzed manually, which is time consuming and subjective. Here, we automate feature extraction of time-lapse microscopy of human embryos with a machine-learning pipeline of five convolutional neural networks (CNNs). Our pipeline consists of (1) semantic segmentation of the regions of the embryo, (2) regression predictions of fragment severity, (3) classification of the developmental stage, and object instance segmentation of (4) cells and (5) pronuclei. Our approach greatly speeds up the measurement of quantitative, biologically relevant features that may aid in embryo selection.

6.
Brain Inj ; 13(5): 355-67, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10367146

RESUMEN

Although ecological validity of traditional tests of memory has been questioned, use of these tests remains the standard in clinical practice. More recently, however, standardized measures with more emphasis on ecological relevance have been developed. One hundred and nineteen adults with diagnosed brain injuries completed traditional instruments of memory assessment, the Luria Nebraska Neuropsychological Battery Memory Scale (LNNB-M) and the Wechsler Memory Scale-Revised (WMS-R). Subjects also completed the Rivermead Behavioural Memory Test (RBMT), an instrument designed to measure everyday memory. Additionally, clinicians rated subjects' day-to-day memory functioning at the rehabilitation facility. Results suggest that RBMT is most accurate in classifying severity of memory impairment as rated by clinicians. The LNNB-M and WMS-R were relatively accurate at classifying severely impaired and unimpaired subjects, but were much less accurate at classifying subjects in the mild and moderate impairment ranges. Implications for interpretation and use of these instruments in rehabilitation settings are discussed.


Asunto(s)
Trastornos de la Memoria/diagnóstico , Pruebas Neuropsicológicas , Adulto , Lesiones Encefálicas/complicaciones , Análisis Discriminante , Femenino , Lateralidad Funcional , Humanos , Masculino , Trastornos de la Memoria/etiología , Reproducibilidad de los Resultados , Índice de Severidad de la Enfermedad
7.
Clin Neuropsychol ; 13(4): 495-508, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10806463

RESUMEN

The present study examined the relationship between memory and orientation to time, place, and personal and general information, as moderated by age, education, and simple attentional ability. A heterogeneous sample of 312 clinical referrals was divided into four groups, according to delayed memory functioning. Patients with globally good, globally poor, poor visual, and poor auditory memory were at differential risk of being disoriented, with the globally poor memory patients having the greatest risk. Overall, poorly oriented patients were older and less educated, with worse recall of digits backward. Discriminant Function Analysis selected visual and auditory memory and age as predictors of orientation. Normative tables stratified by age and memory performance are presented.


Asunto(s)
Inteligencia , Trastornos de la Memoria/diagnóstico , Trastornos de la Memoria/psicología , Memoria , Pruebas Neuropsicológicas , Orientación , Adolescente , Adulto , Factores de Edad , Anciano , Percepción Auditiva , Femenino , Humanos , Illinois , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas/normas , Valores de Referencia , Derivación y Consulta , Muestreo , Estados Unidos , Percepción Visual
8.
Brain Inj ; 12(12): 1025-35, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9876862

RESUMEN

The relationship between performance on neuropsychological measures and the vocational and independent living functioning of individuals with traumatic brain injury was examined. The Wechsler Adult Intelligence Scale-Revised (WAIS-R) IQ and Stroop Color and Word Test scores differentiated individuals who required no assistance with activities of daily living from those requiring some level of assistance. Only the Stroop Color and Word Test scores differentiated individuals who were competitively employed or engaged in degree-oriented education from those who were unemployed or in sheltered or supported employment. Wechsler Memory Scale-Revised (WMS-R) scores did not differentiate these groups.


Asunto(s)
Lesiones Encefálicas/rehabilitación , Pruebas de Inteligencia , Orientación Vocacional , Actividades Cotidianas , Adulto , Lesiones Encefálicas/clasificación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Calidad de Vida
9.
Biodegradation ; 9(3-4): 233-45, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-10022067

RESUMEN

This paper reviews the operation of a full-scale, fixed-bed digester treating a citric acid production wastewater with a COD:sulphate ratio of 3-4:1. Support matrix pieces were removed from the digester at intervals during the first 5 years of operation in order to quantify the vertical distribution of biomass within the digester. Detailed analysis of the digester biomass after 5 years of operation indicated that H2 and propionate-utilising SRB had outcompeted hydrogenophilic methanogens and propionate syntrophs. Acetoclastic methanogens were shown to play the dominant role in acetate conversion. Butyrate and ethanol-degrading syntrophs also remained active in the digester after 5 years of operation. Laboratory-scale hybrid reactor treatment at 55 degrees C of a diluted molasses influent, with and without sulphate supplementation, showed that the reactors could be operated with high stability at volumetric loading rates of 24 kgCOD.m-3.d-1 (12 h HRT). In the presence of sulphate (2 g/l-1; COD/sulphate ratio of 6:1), acetate conversion was severely inhibited, resulting in effluent acetate concentrations of up to 4000 mg.l-1.


Asunto(s)
Bacterias Anaerobias/metabolismo , Industria Química , Ácido Cítrico , Bacterias Reductoras del Azufre/metabolismo , Eliminación de Residuos Líquidos , Biodegradación Ambiental , Biomasa , Butiratos/metabolismo , Metano/metabolismo , Oxígeno/análisis , Propionatos/metabolismo , Sulfatos/análisis , Temperatura
10.
Diagn Microbiol Infect Dis ; 28(2): 75-9, 1997 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9239498

RESUMEN

Cell culture has traditionally been considered the most sensitive method for detecting Chlamydia trachomatis from clinical specimens, but depends upon the organisms being viable at the time of cell inoculation. Furthermore, cell culture is slow and labor intensive. Even when a special transport medium is used, there is a progressive loss of viability of C. trachomatis during transport. The detection of C. trachomatis by cell culture is more rapid when immunofluorescence is used to detect early antigen, but requires considerable experience to interpret. The Amplicor C. trachomatis system is a commercial polymerase chain reaction (PCR)-based assay combined with nucleic acid hybridization for the direct detection of C. trachomatis in urine and swabs of appropriate sites, with results available within 6 h. All specimens for C. trachomatis received by the Royal Perth Hospital Department of Microbiology during the period 1 July 1994 to 30 June 1995 that were suitable for culture and Amplicor PCR were tested by both methods (2029 specimens). Discordant results were obtained in nine cases and resolved by additional testing. Seventy-one specimens were confirmed as true positives, of these Amplicor PCR correctly detected 67 (sensitivity 94.4%) and culture correctly detected 62 (sensitivity 87.3%). The Amplicor PCR assay was found to be more sensitive and as specific as culture. It had the added advantages of ease of use, rapid availability of results, standardization and was more suited than culture to processing large number of specimens.


Asunto(s)
Chlamydia trachomatis/aislamiento & purificación , Reacción en Cadena de la Polimerasa , Células Cultivadas , Femenino , Humanos , Masculino
11.
Aust N Z J Med ; 26(6): 789-92, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9028509

RESUMEN

BACKGROUND: Differences in the hepatitis C virus (HCV) genotype influence the severity of HCV related liver disease and response to interferon therapy. HCV infection is frequent in Australian haemophilia patients who have been exposed repeatedly to multiple HCV genotypes through non HCV virally inactivated clotting factor concentrates. The distribution of the various HCV genotypes in Australian haemophilia patients is unknown. AIM: To examine the HCV genotype distribution and clinical features of HCV associated liver disease in Australian haemophilia patients. METHODS: Forty patients with bleeding disorders who were known to be both HCV antibody and polymerase chain reaction (PCR) positive were evaluated by direct sequencing of the PCR products for the HCV genotype. RESULTS: Genotype 1 was found in 65% of patients (26/40), type 2 in 5% (2/40) and type 3 in 30% (12/40). No genotypes 4 to 6 were found. There was no association between the HCV genotype and the severity of haemophilia, alanine transaminase levels, or the presence of portal hypertension. Unlike European, Asian and American studies where the majority of type 1 infection is subclass 1b, in Australian haemophilia patients it is subclass 1a (73%-19/26) which may have a better prognosis and response to interferon. CONCLUSIONS: Despite patients with haemophilia being exposed to multiple HCV genotypes, it appears that there is no selection advantage of one genotype over another. Australian haemophilia patients with HCV have a different genotype distribution to that reported in other countries and care should be observed in interpreting non Australian studies concerning HCV.


Asunto(s)
Genoma Viral , Hemofilia A/complicaciones , Hepacivirus/genética , Hepatitis C/virología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Australia , Genotipo , Hepacivirus/aislamiento & purificación , Hepatitis C/etiología , Humanos , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa
12.
Antimicrob Agents Chemother ; 40(4): 1017-9, 1996 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8849218

RESUMEN

We tested the antiviral susceptibilities of 30 clinical isolates of herpes simplex virus using the microplate in situ enzyme-linked immunosorbent assay (MISE) and the plaque reduction assay (PRA). There was concordance for 26 of 30 acyclovir results and all 30 foscarnet results. MISE and PRA results each predicted the response to acyclovir in 12 of 14 instances and the response to foscarnet in 8 instances. MISE is more rapid than PRA, has an objective endpoint, and correlates well with the clinical response to therapy.


Asunto(s)
Aciclovir/farmacología , Antivirales/farmacología , Foscarnet/farmacología , Herpes Simple , Pruebas de Sensibilidad Microbiana/métodos , Ensayo de Inmunoadsorción Enzimática , Humanos
13.
J Virol Methods ; 56(1): 85-90, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8690771

RESUMEN

Viral susceptibility testing has been shown to have a role in the management of patients with herpes simplex infections. In this study, 25 isolates of herpes simplex virus representing a broad spectrum of acyclovir-susceptible and -resistant phenotypes were tested using a microplate in situ enzyme-linked immunosorbent assay (MISE). This method is objective and more rapid than the traditional plaque reduction assay (PRA). The previously derived PRA results were not known at the time of testing with the MISE method. The correlation coefficient between PRA and MISE was 0.85. Agreement on sensitive or resistant was reached for 21 of 25 isolates. The standardised microplate in situ ELISA was found to be an acceptable alternative to the plaque reduction assay.


Asunto(s)
Aciclovir/farmacología , Antivirales/farmacología , Ensayo de Inmunoadsorción Enzimática/métodos , Simplexvirus/efectos de los fármacos , Ensayo de Placa Viral/métodos , Humanos , Simplexvirus/aislamiento & purificación
14.
J Virol Methods ; 48(1): 93-108, 1994 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-7962265

RESUMEN

Viral susceptibility testing has been traditionally performed by plaque reduction assay (PRA) which is labour intensive, time consuming and requires subjective input by the reader. An in situ enzyme-linked immunosorbent assay (ELISA) method has been developed with the potential to overcome many of the limitations of PRA, and has been applied to a variety of viruses. Previous reports of ELISA susceptibility assays have shown little standardisation between these methods, or any significant analysis of the variable factors which may influence the outcome of the assay. This study optimised the sensitivity of a microplate in situ ELISA (MISE-test) for the detection of viral growth, manipulated the interaction between cells, virus and acyclovir to determine the effect of their relationship on susceptibility results, and established standard assay conditions based on quality controlled parameters such as assay variability and linear ranges. 33 isolates of HSV-2 were tested for susceptibility to acyclovir by PRA, and the standardised MISE. Factors which were critical to the performance of the MISE included inoculum size, inoculation method, duration of incubation, fixative type, immunoglobulin working strengths and choice of chromogenic substrate. Using the ELISA it was possible to separate sensitive HSV-2 isolates from resistant isolates applying a cutoff ID50 value of 2.0 mg/l. The correlation coefficient between PRA and MISE was 0.65. The standardised microplate in situ ELISA was found to be an acceptable alternative to the plaque reduction assay.


Asunto(s)
Aciclovir/farmacología , Ensayo de Inmunoadsorción Enzimática/normas , Pruebas de Sensibilidad Microbiana/normas , Simplexvirus/efectos de los fármacos , Animales , Células Cultivadas , Chlorocebus aethiops , Farmacorresistencia Microbiana , Ensayo de Inmunoadsorción Enzimática/instrumentación , Fibroblastos , Herpes Genital/virología , Humanos , Pulmón , Pruebas de Sensibilidad Microbiana/instrumentación , Visón , Simplexvirus/crecimiento & desarrollo , Simplexvirus/aislamiento & purificación , Células Vero , Ensayo de Placa Viral
15.
Eur J Cancer ; 30A(14): 2085-90, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-7857708

RESUMEN

The aim of this study was to assess the efficacy and toxicity of intensive chemotherapy, administered without dose reduction, with cranial and thoracic radiotherapy given when possible as a single fraction in small cell lung cancer. 87 patients were eligible on the basis of good performance status, normal or near normal biochemistry and clinical staging, 73 limited and 14 extensive stage, computed tomography scanning was not mandatory. Six cycles of carboplatin, ifosfamide and etoposide with vincristine on day 15 at 4 weekly intervals were planned. Dosages were not reduced in response to myelosuppression. Prophylactic cranial irradiation (PCI) as a single fraction after the first cycle and thoracic irradiation (when possible as a single fraction) following the third cycle were delivered. Seventy-two per cent of patients completed the protocol. Complete response rate was 55% and 26% of patients had a partial response. The median nadirs of neutropenia were 0.5 x 10(9)/l and thrombocytopenia 14 x 10(9)/l, with 6% probable treatment-related deaths. Performance status and dyspnoea improved markedly to normal or near normal levels following the second course. Brain metastases occurred in 13% of patients. The median survival was 16.2 months with a 2-year survival of 31% (95% confidence interval, 24-41%) for a minimum follow-up of 26 months. These results compare favourably with other combined modality studies, using multiple radiotherapy fractions with cisplatin-based combinations and dosage reduction for patients staged in more anatomical detail. The toxicity spectrum and efficacy data could lead to the use of this chemotherapy regimen with haematopoietic growth factors and, in the future, peripheral blood progenitor cell rescue.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Células Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Encefálicas/prevención & control , Carboplatino/administración & dosificación , Carcinoma de Células Pequeñas/mortalidad , Carcinoma de Células Pequeñas/radioterapia , Terapia Combinada , Etopósido/administración & dosificación , Femenino , Humanos , Ifosfamida/administración & dosificación , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/radioterapia , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Resultado del Tratamiento , Vincristina/administración & dosificación
16.
Br J Radiol ; 65(780): 1075-82, 1992 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1337496

RESUMEN

Krypton-81m gas, by virtue of its imaging characteristics, is often considered the "gold standard" for ventilation scintigraphy but its use is restricted by its high cost and limited availability. The new radiopharmaceutical 99Tcm-Technegas, a suspension of ultrafine technetium-99m labelled carbon particles, produces high-quality images of ventilation and has the advantage of continuous availability. As part of our evaluation of Technegas the two were compared in 40 patients with a variety of established respiratory diseases. Disparities were seen in five patients in five diagnostic groups and may be a consequence of the differing physical properties of the two agents and the different inhalation techniques used. In addition two interesting features were noted on the Technegas images. (1) Hot spots were seen in 50% of patients, particularly in those with a degree of airways obstruction; (2) preferential basal deposition of activity was seen in 30%, particularly in patients with idiopathic pulmonary fibrosis. Both features were significantly associated with parameters of pulmonary function indicating obstructive lung disease in the former case and restrictive lung disease in the latter.


Asunto(s)
Radioisótopos de Criptón , Enfermedades Pulmonares/diagnóstico por imagen , Pulmón/diagnóstico por imagen , Pertecnetato de Sodio Tc 99m , Adulto , Anciano , Femenino , Volumen Espiratorio Forzado , Capacidad Residual Funcional , Humanos , Pulmón/fisiopatología , Enfermedades Pulmonares/fisiopatología , Masculino , Persona de Mediana Edad , Cintigrafía , Respiración , Capacidad Pulmonar Total , Capacidad Vital
18.
Br J Radiol ; 65(773): 403-8, 1992 May.
Artículo en Inglés | MEDLINE | ID: mdl-1319255

RESUMEN

Inhalation of the ventilatory radiopharmaceutical 99Tcm Technegas leads, in some patients, to symptoms that may be attributed to temporary lowering of oxygen saturation. In order to evaluate this, oxygen saturation was measured by pulse oximetry in a series of patients undergoing Technegas ventilation scintigraphy. A decrease in oxygen saturation was recorded in 87% of the patient group. The mean change, as a percentage of the initial value, was 8.3% (range 1-24%). Hypoxia arising in association with Technegas administration may be reduced by pre-oxygenation. In patients who were pre-oxygenated, oxygen saturation did not fall below 85% (PaO2: 50 mmHg) but in 39% of those not pre-oxygenated the value fell below this level. Oxygen saturation was also monitored in a series of patients undergoing perfusion scintigraphy. In 17% of patients a decrease was recorded (range 2-11%). In view of the large number of perfusion scans performed annually in this department and elsewhere without untoward effect, such temporary decreases in oxygen saturation presumably present no hazard to the patient.


Asunto(s)
Hipoxia/etiología , Pulmón/diagnóstico por imagen , Pertecnetato de Sodio Tc 99m/efectos adversos , Agregado de Albúmina Marcado con Tecnecio Tc 99m/efectos adversos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Albúminas/efectos adversos , Femenino , Grafito/efectos adversos , Humanos , Masculino , Persona de Mediana Edad , Oxígeno/administración & dosificación , Oxígeno/sangre , Cintigrafía
19.
Clin Radiol ; 45(4): 256-9, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1395383

RESUMEN

Many patients with bronchiectasis have diffuse airways obstruction and this may be the dominant symptom. This study was performed to assess whether the severity of airway obstruction in these patients is related to duration of bronchiectatic symptoms or to the extent of bronchiectasis demonstrated by computed tomography (CT). Twenty-six patients were studied. The severity of airflow obstruction was measured by standard physiological testing and the extent of bronchiectasis demonstrated by CT was assessed using a scoring system. Correlation was measured by Kendall's rank correlation coefficient. A highly significant correlation between FEV1 and CT score was demonstrated and a significant correlation was also observed between FEV1 and duration of symptoms. A weak correlation was present between CT score and symptom duration.


Asunto(s)
Bronquiectasia/complicaciones , Bronquiectasia/diagnóstico por imagen , Enfermedades Pulmonares Obstructivas/etiología , Pulmón/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adulto , Anciano , Femenino , Volumen Espiratorio Forzado , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Cese del Hábito de Fumar , Factores de Tiempo
20.
Gut ; 32(9): 1084-6, 1991 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-1655591

RESUMEN

The hepatocellular carcinomas that develop in patients treated with androgens have previously been associated with a benign clinical outcome. We describe a man who developed a hepatocellular carcinoma after 24 years of androgen treatment, whose tumour initially showed partial regression after withdrawal of androgens but subsequently pursued an aggressive and fatal course.


Asunto(s)
Carcinoma Hepatocelular/inducido químicamente , Neoplasias Hepáticas/inducido químicamente , Metiltestosterona/efectos adversos , Carcinoma Hepatocelular/patología , Humanos , Hipogonadismo/tratamiento farmacológico , Neoplasias Hepáticas/patología , Cuidados a Largo Plazo , Masculino , Persona de Mediana Edad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...