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Biomedical subjects

W Ball

Publications and source records attributed to W Ball.

14 recordsLinked to original sources
PubMed1996

Anti-T cell receptor monoclonal antibody prolongs transgene expression following adenovirus-mediated in vivo gene transfer to mouse synovium.

There are no cures for rheumatoid arthritis (RA) or other inflammatory autoimmune arthropathies. Gene transfer to the synovium would allow administration of anti-inflammatory gene products directly to the articular space where they could exert a local down-regulatory effect on the autoimmune process. Several well-characterized murine models of arthritis closely resemble RA immunologically, genetically, and histopathologically. To determine whether the mouse could serve as a model for gene transfer to the synovium, a methodology was developed to reproducibly inject a 5-microliter volume into the articular space of the mouse knee. Using this approach, Av1LacZ4, an E1a-E3-deleted adenoviral (Ad5) vector expressing the lacZ transgene, was delivered intra-articularly (5 x 10(8) pfu). lacZ expression was observed in the articular synovium for at least 14 days. Biochemical quantitation demonstrated a gradual loss of transgene expression, associated with an early, predominantly neutrophilic, inflammatory response that progressed to a lymphocytic infiltrate, followed by gradual resolution over a 3-week period. Pretreatment with the anti-TCR monoclonal antibody (mAb) H57 resulted in a significant reduction in lymphocytic infiltration and a prolongation of transgene expression. These data demonstrate that transgenes can be delivered to the mouse knee joint space, affording a powerful tool to test the potential of gene therapy as a therapeutic modality for RA. As in other systems, the immune response against recombinant adenoviral vectors may limit the extent and duration of gene expression in the synovium. Anti-T cell mAbs may be useful in inhibiting this immune response.

Adenoviruses, Human↗
PubMed1996

A 56-year-old woman with recurrent episodes of weakness and hypoglycemia.

The differential diagnosis for a 56-year-old woman with recurrent episodes of weakness and hypoglycemia is discussed in the setting of a clinicopathological conference at the Louisiana State University Medical Center in Shreveport, Louisiana. The diagnostic approach to the workup of a patient presenting with hypoglycemia is outlined.

Female↗
PubMed1995

Paroxysmal supraventricular tachycardia of unusual etiology: a case report.

Paroxysmal supraventricular tachycardia (PSVT) is a serious cardiac disturbance that can arise spontaneously or be initiated by noncardiac mechanisms. An occurrence of this dysrhythmia in a 55-year-old male undergoing monitored anesthesia care for excision of a subxiphoid subcutaneous mass is reported. The unusual cause of this patient's ectopy is discussed. The nature and treatment of PSVT are reviewed, as are the clinical considerations for anesthetists who encounter a comparable clinical problem.

Electrodes, Implanted↗
PubMed1987

Radiographic characteristics of skull fractures resulting from child abuse.

Radiographic characteristics of skull fractures in 39 cases of documented child abuse were compared with skull fractures in 95 cases of accidental injury to determine if differential features could be identified. All children were less than 2 years old. Emergency room and hospital records for these patients were also reviewed. The results of this study show that clinical features did not provide any clues as to whether the children had been injured by abuse or by accident. However, it was found that multiple fractures, bilateral fractures, and fractures crossing sutures occurred significantly more often in abuse cases than in accidental injury. When such fractures are present, abuse should be suspected.

Accidents↗
PubMed1983

Postasphyxial encephalopathy in full-term infants: ultrasound diagnosis.

Abnormal cranial ultrasound findings are described in 18 infants with severe asphyxia. The examinations performed within the first 7 days after the asphyxial episode frequently showed obliteration of the ventricles and extra-axial fluid spaces with mildly increased cerebral echogenicity, presumably representing cerebral edema. Others showed diffusely abnormal parenchymal echogenicity with normal ventricles and sulci. Ultrasound findings seen after the first week of life included increased size of the ventricles and extra-axial fluid, the result of cerebral atrophy. The sensitivity, specificity, and accuracy of both early and late abnormal ultrasonograms were calculated for predicting an abnormal neurological outcome. While the sensitivity of the abnormal early (performed within 7 days of birth) ultrasonogram was relatively low (46%), the sensitivity of an abnormal late (performed after 7 days) ultrasonogram was high (86%). The specificity for both abnormal early and late ultrasound was 100%. These findings suggest that cranial ultrasonography can be used as a screening procedure to provide information about the neurologic outcome to clinicians caring for these infants.

Asphyxia Neonatorum↗
PubMed1975

Determination of ammonia inhibition in fabric impregnated with antimicrobials.

A new method is described for determining the presence or absence of ammonia produced by urealytic microorganisms, using fabric which has been treated with an antimicrobial. Circular disks of fabric treated with various concentrations of an antimicrobial are placed in the bottoms of snap-on lid petri dishes. Nutrient medium containing urea, an indicator, and a dilution of an overnight culture of Proteus mirabilis is applied to the fabric disks. The lids are snapped on and the dishes are incubated at 37 degrees C. By examination of the fabric disks at regular intervals of time for a color change from white to red, one may determine whether the concentration of antimicrobial in the fabric is sufficient to inhibit the production of ammonia by a urealytic microorganism.

Ammonia↗
PubMed1971

Infant responses to impending collision: optical and real.

Twenty-four infants ranging in age from 2 to 11 weeks responded to symmetrically expanding shadows, which optically specify an approaching object, with an integrated avoidance response and upset. This response did not occur for asymmetrically expanding shadows nor for contracting shadows that specify an object on a miss path and a receding object. The response was observed in all the infants regardless of age, and the addition of kinetic depth information to the displays did not increase the intensity or likelihood of the response. In a second experiment, seven infants defensively reacted to the approach of a real object except when it was on a miss path.

Avoidance Learning↗
PubMedDate not supplied

Multi-level adaptive segmentation of multi-parameter MR brain images.

MR brain image segmentation into several tissue classes is of significant interest to visualize and quantify individual anatomical structures. Traditionally, the segmentation is performed manually in a clinical environment that is operator dependent and may be difficult to reproduce. Though several algorithms have been investigated in the literature for computerized automatic segmentation of MR brain images, they are usually targeted to classify image into a limited number of classes such as white matter, gray matter, cerebrospinal fluid and specific lesions. We present a novel model-based method for the automatic segmentation and classification of multi-parameter MR brain images into a larger number of tissue classes of interest. Our model employs 15 brain tissue classes instead of the commonly used set of four classes, which were of clinical interest to neuroradiologists for following-up with patients suffering from cerebrovascular deficiency (CVD) and/or stroke. The model approximates the spatial distribution of tissue classes by a Gauss Markov random field and uses the maximum likelihood method to estimate the class probabilities and transitional probabilities for each pixel of the image. Multi-parameter MR brain images with T(1), T(2), proton density, Gd+T(1), and perfusion imaging were used in segmentation and classification. In the development of the segmentation model, true class-membership of measured parameters was determined from manual segmentation of a set of normal and pathologic brain images by a team of neuroradiologists. The manual segmentation was performed using a human-computer interface specifically designed for pixel-by-pixel segmentation of brain images. The registration of corresponding images from different brains was accomplished using an elastic transformation. The presented segmentation method uses the multi-parameter model in adaptive segmentation of brain images on a pixel-by-pixel basis. The method was evaluated on a set of multi-parameter MR brain images of a twelve-year old patient 48h after suffering a stroke. The results of classification as compared to the manual segmentation of the same data show the efficacy and accuracy of the presented methods as well as its capability to create and learn new tissue classes.

Algorithms↗