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Biomedical subjects

E A Bradley

Publications and source records attributed to E A Bradley.

At least 19 recordsLinked to original sources
PubMed2001

Adrenocortical carcinoma metastatic to the orbit.

PURPOSE: To describe the clinical course and histopathologic features of a patient with adrenocortical carcinoma metastatic to the orbit. METHODS: Case report and literature review. RESULTS: A 24-year-old man first came to medical attention because of symptoms referable to a 4.47-kg, nonfunctioning carcinoma of the left adrenal cortex. Several metastases ensued, including a large tumor to the right superior lateral bony orbit with extension to the brain, temporalis fossa, and orbit proper. The tumor was resected with the use of a combined neurosurgical, ophthalmic, and craniofacial approach. The patient died of widespread metastatic disease 15 months after the orbital operation. CONCLUSIONS: Metastasis to the orbit from adrenocortical carcinoma is rare. Surgical resection is the treatment of choice, with adjunctive radiation therapy and chemotherapy in some cases. The prognosis is poor.

Adrenal Cortex Neoplasms↗
PubMed2001

Radiation-induced meningiomas involving the orbit.

PURPOSE: To review the clinical features and outcomes of patients with radiation-induced meningiomas involving the orbit. DESIGN: Retrospective case series. PARTICIPANTS: Eight patients with radiation-induced meningiomas affecting the orbit. METHODS: Clinical and pathologic data of the patients were reviewed. MAIN OUTCOME MEASURES: Age at diagnosis, mean interval between radiation therapy and meningioma diagnosis, tumor recurrence, histologic atypia, and mean follow-up time after initial diagnosis. RESULTS: The mean age at diagnosis was 42 years (range, 21 years to 70 years). The mean interval between radiation therapy and meningioma diagnosis was 26 years (range, 3 years to 54 years). All patients underwent gross total resection or subtotal resection of the meningioma. Five tumors (62.5%) recurred, based on clinical findings and CT imaging. The mean interval between resection of the meningioma and recurrence was 3 years (range, 9 months to 9 years). Three patients (37.5%) had atypical meningiomas. One patient (12.5%) had multiple tumors. The mean follow-up interval was 7 years after initial diagnosis of the meningioma (range, 15 months to 19 years). CONCLUSIONS: This series of radiation-induced meningiomas, the first in the ophthalmic literature, illustrates the aggressive nature of this tumor.

Adult↗
PubMed2001

Graves ophthalmopathy.

Graves ophthalmopathy (GO) is an autoimmune disease that typically affects the thyroid gland and the orbit. The roles of the thyroid stimulating hormone receptor and cellular and humoral immunity in the pathogenesis of GO are being investigated. Investigators are gaining insights into the epidemiology of GO as it relates to other ocular and autoimmune diseases. Several possible tools for assessing GO disease activity are being studied. Medical and radiation therapy for GO recently have been evaluated prospectively. Orbital surgeons continue to refine orbital decompression techniques to improve patient outcomes and minimize surgical complications.

Graves Disease↗
PubMed2001

Surgical correction of blepharoptosis in patients with myasthenia gravis.

PURPOSE: To describe the results of surgical correction of blepharoptosis in a series of patients with myasthenia gravis (MG). METHODS: In this retrospective case series, we reviewed the medical records of all patients with MG who did not respond to medical therapy and underwent surgical correction for blepharoptosis at the Mayo Clinic between 1985 and 1999. The primary outcome measure was change in interpalpebral eyelid fissure height. RESULTS: Sixteen blepharoptosis procedures were performed on 10 patients with MG. Eight of the 10 patients had ocular MG. Two of the 10 patients had systemic MG. Of the 16 procedures performed, 9 were external levator advancements (ELA), six were frontalis slings, and one was a tarsomyectomy. Patients were followed postoperatively for an average of 34 months (range, 14-126 months). The amount of ptosis was quantified pre- and postoperatively for seven of the nine eyelids that underwent ELA. For these seven eyelids (five patients), there was a statistically significant improvement in the mean interpalpebral eyelid fissure height from 3.7 mm preoperatively to 7.8 mm postoperatively, with a mean difference of 4.1 mm (95% confidence interval 1.9 mm to 6.25 mm, p = 0.0038). Postoperative complications included worsened diplopia in one patient with ELA and exposure keratopathy in one patient with frontalis sling. Two of the ELA eyelids developed recurrent ptosis requiring additional surgery more than 2 years after the initial procedure. CONCLUSIONS: Blepharoptosis surgery can achieve eyelid elevation in patients who have failed to respond to medical therapy for MG. Potential complications include worsened diplopia and exposure keratopathy.

Adult↗
PubMed2000

Surgical correction of blepharoptosis in patients with myasthenia gravis.

PURPOSE: To describe the results of surgical correction of blepharoptosis in a series of patients with myasthenia gravis. METHODS: We reviewed the medical records of all patients with myasthenia gravis who underwent surgical correction for blepharoptosis at the Mayo Clinic between 1985 and 1999. The primary outcome measure was change in interpalpebral eyelid fissure height. RESULTS: Eighteen blepharoptosis procedures were performed on 11 patients with myasthenia gravis. Eight of the 11 patients had ocular myasthenia gravis, and 3 had systemic myasthenia gravis. Of the 18 procedures performed, 11 were external levator advancements (ELA), 6 were frontalis slings, and 1 was a tarsomyectomy. Patients were followed up postoperatively for an average of 34 months (range, 9 to 126 months). The amount of ptosis was quantified preoperatively and postoperatively for 9 of the 11 eyelids that underwent ELA. For these eyelids, there was a statistically significant improvement in the mean interpalpebral eyelid fissure height, from 4.2 mm preoperatively to 8.1 mm postoperatively, with a mean difference of 3.9 mm (95% confidence interval, 2.3 to 5.5 mm; P = .0005). Postoperative complications included worsened diplopia in 1 patient who underwent ELA and exposure keratopathy in 1 patient who underwent a frontalis sling procedure. Two of the eyelids that underwent ELA developed recurrent ptosis, requiring additional surgery more than 2 years after the initial procedure. CONCLUSION: Surgical correction of blepharoptosis is an appropriate treatment option in patients with myasthenia gravis who fail medical therapy. Potential complications include worsened diplopia and exposure keratopathy.

Adult↗
PubMed1998

Transcatheter uterine artery embolisation to treat large uterine fibroids.

Bilateral uterine artery embolisation was performed to treat eight women with symptomatic large fibroids requiring treatment. Uterine volume was quantitatively assessed by magnetic resonance imaging. Both uterine arteries were occluded effectively in all women, and the procedure was well tolerated, with a 24-36 hour admission for pain relief. The level of pain experienced was variable, but well controlled. Some women experienced intermittent vaginal discharge and pain following the procedure. Improvement of symptoms occurred in six of the seven women and the eighth woman conceived. There were no significant complications. At three months four women had a uterine volume of < 350 cm3. Embolisation appears to be a good alternative to surgery, but longer follow up is required to evaluate the long term effects and to determine those patients for whom the procedure is suitable.

Adult↗
PubMed1994

A study of the physiological mechanisms contributing to neurotensin-induced hypothermia.

Although central administration of neurotensin is known to produce marked hypothermia in the rat, there are no studies which have investigated the effects of neurotensin on oxygen consumption and heat exchange, the physiological mechanisms which are the principal contributors to changes in body temperature. We report a significant correlation between dose and the duration and degree of post-injection heat loss following central administration of neurotensin. Oxygen consumption does not appear to be affected by neurotensin. We suggest that it is this dose-dependent, post-injection heat loss which is responsible for neurotensin-induced hypothermia. Furthermore, the hypothermia does not appear to reflect a change in set point.

Animals↗
PubMed1993

Modeling the structure of Pyrococcus furiosus rubredoxin by homology to other X-ray structures.

The three-dimensional structure of rubredoxin from the hyperthermophilic archaebacterium, Pyrococcus furiosus, has been modeled from the X-ray crystal structures of three homologous proteins from Clostridium pasteurianum, Desulfovibrio gigas, and Desulfovibrio vulgaris. All three homology models are similar. When comparing the positions of all heavy atoms and essential hydrogen atoms to the recently solved crystal structure (Day, M. W., et al., 1992, Protein Sci. 1, 1494-1507) of the same protein, the homology model differ from the X-ray structure by 2.09 A root mean square (RMS). The X-ray and the zinc-substituted NMR structures (Blake, P. R., et al., 1992b, Protein Sci. 1, 1508-1521) show a similar level of difference (2.05 A RMS). On average, the homology models are closer to the X-ray structure than to the NMR structures (2.09 vs. 2.42 A RMS).

Amino Acid Sequence↗
PubMed1993

Investigations of the thermostability of rubredoxin models using molecular dynamics simulations.

The affects of differences in amino acid sequence on the temperature stability of the three-dimensional structure of the small beta-sheet protein, rubredoxin (Rd), was revealed when a set of homology models was subjected to molecular dynamics simulations at relatively high temperatures. Models of Rd from the hyperthermophile, Pyrococcus furiosus (Pf), an organism that grows optimally at 100 degrees C, were compared to three mesophilic Rds of known X-ray crystal structure. Simulations covering the limits of known Rd thermostabilities were carried out at temperatures of 300 K, 343 K, 373 K, and 413 K. They suggest that Rd stability is correlated with structural dynamics. Because the dynamic behavior of three Pf Rd models was consistently different from the dynamic behavior of the three mesophilic Rd structures, detailed analysis of the temperature-dependent dynamic behavior was carried out. The major differences between the models of the protein from the hyperthermophile and the others were: (1) an obvious temperature-dependent transition in the mesophilic structures not seen with the Pf Rd models, (2) consistent AMBER energy for the Pf Rd due to differences in nonbonded interaction terms, (3) less variation in the average conformations for the Pf Rd models with temperature, and (4) the presence of more extensive secondary structure for the Pf Rd models. These unsolvated dynamics simulations support a simple, general hypothesis to explain the hyperthermostability of Pf Rd. Its structure simplifies the conformational space to give a single minimum accessible over an extreme range of temperatures, whereas the mesophilic proteins sample a more complex conformational space with two or more minima over the same temperature range.

Computer Simulation↗
PubMed1992

BK virus.

BK virus is a human polyoma virus that infects the renal epithelium and remains latent until immunosuppression triggers reactivation. After reactivation, BK virus can be detected in the urine by methods currently available in the clinical laboratory. Correlations can be made between BK viruria and the occurrence of both renal and hepatic pathologies. BK virus is emerging as a significant pathogen in transplant patients. Additionally, the presence of BK virus DNA in primary brain and pancreatic tumors suggests that it may have oncogenic potential. Thus far, attempts to treat BK virus infection have been ineffective, though research has opened new avenues for treatment possibilities. Prevention of BK virus and other latent viral reactivation remains a challenge to viral research.

BK Virus↗
PubMed1992

Murine typhus: forgotten but not gone.

An occasional patient presents the classical symptoms of a disease that has become uncommon. Typhus is an example of such a disease, since it is now well contained through control of its rodent reservoir. It is readily treated with tetracycline or one of its long-acting analogues, doxycycline or minocycline. Because typhus is infrequently encountered, the physician may not initially include it in his differential diagnosis. Our case serves as a remainder that with the increasingly frequent movement of persons from one geographic area to another, the uncommon rickettsial infection, murine typhus, should continue to be in the differential of a febrile patient. Furthermore, our case underscores the importance of including typhus in the differential of typhoid fever.

Acute Disease↗
PubMed1975

Comparison of visual and tactile learning in octopus after lesions to one of the two memory systems.

Sets of animals with lesions to either the vertical lobe or median inferior frontal lobe were trained first visually and then by touch. Lesions of the vertical lobe system did not affect the increase produced by food in tendency to attack a moving figure in the visual field. Any lesion that interrupted the circuit through the vertical lobe greatly impaired the capacity to inhibit attacks on crabs when these attacks resulted in shocks. Removal of the median inferior frontal lobe did not impair this capacity to learn not to attack a crab in the octopus's visual field. The capacity to learn to respond positively to a black disc but to avoid a white one was grossly impaired by an interruption of the vertical lobe circuit. After such operations the animals showed a strong preference for white over black. The capacity to learn to discriminate between black and white was not affected by removal of the median inferior frontal lobe. Animals with interruptions of the vertical lobe circuit could learn to make discrimination between white as a positive figure and black as a negative one, but they made more mistakes than controls. Most mistakes consisted of attacks on the negative (black) figure, but there were also some failures to attack the white. In tactile discrimination between rough and smooth spheres given successively, animals with vertical lobe lesions were, under some circumstances, less accurate than controls. They took more objects than controls. They were less able than controls to reverse the the discrimination. After removal of the median inferior frontal lobe tactile discrimination was greatly impaired. The animals showed a strong preference for rough objects and could not learn to take smooth objects. However, they showed improvement in discrimination when trained with smooth negative and are therefore not wholly incapable of long-term memory storage.

Agonistic Behavior↗