John Howieson
Oregon Health & Science University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by John Howieson.
Neurosurgery | 1986
Edward A. Neuwelt; John Howieson; E. P. Frenkel; H. D. Specht; R. Weigel; C. G. Buchan; Suellen A. Hill
Reversible osmotic blood-brain barrier (BBB) modification was used in 38 patients with glioblastoma to enhance the delivery of chemotherapeutic agents. The patients ranged in age from 14 to 70 years (mean, 43), and all had prior surgery and radiation; 5 had also received systemic chemotherapy. Karnofsky Performance Status (KPS) scores ranged from 60 to 100% (mean, 79) on admission to the treatment program. Barrier modification was achieved by intracarotid or intravertebral artery infusion of mannitol, and a chemotherapy regimen of methotrexate, cytoxan, and procarbazine was given in conjunction with barrier modification. The 38 glioblastoma patients were compared to two control groups of patients with glioblastoma; these encompassed 14 patients treated with surgery and radiation and 8 treated with surgery, radiation, and systemic chemotherapy. Survival analysis using the Cox Proportional Hazards Regression Model (corrected for age, sex, presence or absence of necrosis, and functional status) showed that patients receiving chemotherapy with BBB modification had a statistically significant (P = 0.0006) longer expected survival (17.5 months) than the control groups (12.8 and 11.4 months, respectively). Presently 16 patients of the barrier-enhanced treatment group are alive at 5 to 42 months from diagnosis (median, 20) with KPS scores ranging from 40 to 90% (median, 65). The neurological complications seen included a stroke-like syndrome in 3 patients (1 with decreased motor movement in the hand, 1 with marked hemiparesis, and 1 with hemiplegia), transient exacerbation of preexisting neurological deficits lasting 2 to 3 days, and a 15% incidence of seizures during or within 24 hours of the BBB modification. In 2 of the 38 patients, radiographic documentation of central nervous system tumor regression concurrent with the development of new tumor nodule(s) in portions of the brain distant from the region of osmotic BBB opening was seen. These studies indicate that chemotherapeutic drug delivery to tumors (as well as surrounding brain) can be augmented by osmotic BBB modification and that such therapy can result in a prolongation of survival.
Neurology | 1993
Diane B. Howieson; L. A. Holm; J. Kaye; Barry S. Oken; John Howieson
We examined cognition on a wide range of standardized neuropsychological tests in two groups of optimally healthy, elderly volunteers. One was composed of community-dwelling, functionally independent individuals aged 84 years and older, and the other group was nearly 20 years younger. The effect of aging was greatest on visual perceptual and constructional tasks rather than on memory tasks. Many cognitive functions were relatively well preserved in the optimally healthy oldest old.
Radiology | 1965
John Howieson; Alfonso Escobar; Rocca Garofalo
Acute necrotizing encephalitis is a viral disease affecting the central nervous system and other organs. It is differentiated from other viral encephalitides by its predilection for involvement of cingulum, fornix, hippocampus, the temporal cortex, and less frequently the cortex of the occipital lobe and the insular region of the frontal lobe (1). In approximately 50 per cent of the cases unilateral temporal lobe involvement is revealed at autopsy (2). Nine cases showing radiologic findings have been reported (3–5), in 2 of which the patient survived. One additional case with radiologic findings will be reported in this paper. As it has been suggested that temporal lobe decompression may be a significant factor in survival (2), it seems important that radiologists should become aware of the clinicoradiologic picture associated with this disease. The findings of a temporal lobe mass in our case, as in those previously reported (except one in which a frontal lobe mass was found (6», are not specific for thi...
Radiology | 1963
John Howieson
Hepatic artery aneurysm is a rare entity, 130 eases having been reported to date (1–5). The most recent report (5) included a review of the pertinent literature and a discussion of possible etiologies. This communication adds 2 cases, both of which were treated successfully, increasing the total of successfully treated cases from 21 to 23. Case Reports Case I: R. E. N., a 30-year-old man, experienced severe pain in the epigastrium after pulling on a bulldozer starter rope. The pain reached a peak of intensity in approximately thirty minutes, thereafter becoming constant with excruciating episodes not relieved by parenteral medication, antacids, and bland diet. The pain had no relationship to meals but was partially relieved by stretching and hot baths. Physical examination was negative except for the presence of a small area of induration in the upper abdomen in the midline, over which a bruit was heard intermittently. On May 10, 1962, an exploratory laparotomy was performed. Palpation in the region of th...
Radiology | 1966
John Howieson; Edward M. Higgins
In certain limited applications a small radiographic film size is adequate. Examples of such applications are radiographic confirmation of the position of a cannula in the internal or common carotid artery (Fig. 1), exclusion of subintimal injection after placement of an arterial cannula, confirmation of the position of an electrode for percutaneous cordotomy, or stereotaxis during cryohypophysectomy (Fig. 2). Where the small film size is applicable the film cost per exposure can be reduced from approximately
JAMA Neurology | 1994
Jeffrey Kaye; Barry S. Oken; Diane B. Howieson; John Howieson; Lynn A. Holm; Karen M. Dennison
2.00 to
American Journal of Neuroradiology | 1992
Simon Roman-Goldstein; D L Goldman; John Howieson; R Belkin; Edward A. Neuwelt
0.25 per film and the equipment cost from more than
Radiology | 1991
Val M. Runge; William G. Bradley; Michael Brant-Zawadzki; Mark J. Carvlin; Debra N. DeSimone; Bruce L. Dean; William P. Dillon; Burton P. Drayer; Adam E. Flanders; Steven E. Harms; Victor M. Haughton; John Howieson; Stephen E. Joy; Emanuei Kanal; Ashok J. Kumar; Te Hua Liu; Robert B. Lufkin; Kenneth R. Maravilla; Rubin S. Mezrich; Michael A. Mikhael; Frank W. Morgan; S. N. Nadel; Steven R. Pollei; Stephen J. Pomeranz; Ann C. Price; Ruth G. Ramsey; William T. C. Yuh; James V. Zelch
1,500.00 to less than
JAMA Neurology | 1982
Robert N. Nishimura; David Stepanek; John Howieson; John P. Hammerstad
100.00 by substitution of a modified Polaroid camera back for the Polaroid cassette and processor. The modification is simple and can be carried out without expensive tools or special skills. We have employed a Polaroid camera back designed for use with the Tektronix oscilloscope camera model C12. The camera back has, in front of the film plane, an opening with an opaque sliding cover so that the camera back can be ...
American Journal of Neuroradiology | 1993
John Howieson; Jeffrey Kaye; L Holm; Diane B. Howieson