Search PubMed⌕ Search

Biomedical subjects

G J Harris

Publications and source records attributed to G J Harris.

At least 19 recordsLinked to original sources
PubMed2006

Orbital blow-out fractures: surgical timing and technique.

PURPOSE: To recommend a tailored approach to surgical timing in the repair of orbital blow-out fractures, and to offer suggestions for improved functional and aesthetic surgical outcomes. METHODS: Traditional guidelines for surgical timing are reviewed. An evidence-based approach that considers soft-tissue disruption relative to bone-fragment separation is presented. The author's techniques for repair of isolated orbital floor, isolated medial wall, and combined floor-medial wall fractures are presented. RESULTS: As demonstrated previously, greater degrees of soft-tissue incarceration or displacement, with presumably greater intrinsic damage and subsequent fibrosis, result in poorer motility outcomes despite complete release of soft tissues. There is a suggestion that earlier intervention for such injuries might improve outcomes. Lower fornix and transcaruncular incisions, careful extrication of incarcerated tissue, and thin alloplastic implants have proven successful in the author's hands. CONCLUSIONS: The degree of soft-tissue displacement relative to bone fragment distraction, as depicted in preoperative computed tomography (CT) scans, should be considered in the timing of surgery. Incisions, soft-tissue handling, and implant material, thickness, and positioning can all affect the functional and aesthetic outcomes.

Esthetics↗
PubMed2003

Dissociations of cerebral cortex, subcortical and cerebral white matter volumes in autistic boys.

High-functioning autistic and normal school-age boys were compared using a whole-brain morphometric profile that includes both total brain volume and volumes of all major brain regions. We performed MRI-based morphometric analysis on the brains of 17 autistic and 15 control subjects, all male with normal intelligence, aged 7-11 years. Clinical neuroradiologists judged the brains of all subjects to be clinically normal. The entire brain was segmented into cerebrum, cerebellum, brainstem and ventricles. The cerebrum was subdivided into cerebral cortex, cerebral white matter, hippocampus-amygdala, caudate nucleus, globus pallidus plus putamen, and diencephalon (thalamus plus ventral diencephalon). Volumes were derived for each region and compared between groups both before and after adjustment for variation in total brain volume. Factor analysis was then used to group brain regions based on their intercorrelations. Volumes were significantly different between groups overall; and diencephalon, cerebral white matter, cerebellum and globus pallidus-putamen were significantly larger in the autistic group. Brain volumes were not significantly different overall after adjustment for total brain size, but this analysis approached significance and effect sizes and univariate comparisons remained notable for three regions, although not all in the same direction: cerebral white matter showed a trend towards being disproportionately larger in autistic boys, while cerebral cortex and hippocampus-amygdala showed trends toward being disproportionately smaller. Factor analysis of all brain region volumes yielded three factors, with central white matter grouping alone, and with cerebral cortex and hippocampus-amygdala grouping separately from other grey matter regions. This morphometric profile of the autistic brain suggests that there is an overall increase in brain volumes compared with controls. Additionally, results suggest that there may be differential effects driving white matter to be larger and cerebral cortex and hippocampus-amygdala to be relatively smaller in the autistic than in the typically developing brain. The cause of this apparent dissociation of cerebral cortical regions from subcortical regions and of cortical white from grey matter is unknown, and merits further investigation.

Autistic Disorder↗
PubMed2001

Comparison of diameter and perimeter methods for tumor volume calculation.

PURPOSE: Lesion volume is often used as an end point in clinical trials of oncology therapy. We sought to compare the common method of using orthogonal diameters to estimate lesion volume (the diameter method) with a computer-assisted planimetric technique (the perimeter method). METHODS: Radiologists reviewed 825 magnetic resonance imaging studies from 219 patients with glioblastoma multiforme. Each study had lesion volume independently estimated via the diameter and perimeter methods. Cystic areas were subtracted out or excluded from the outlined lesion. Inter- and intrareader variability was measured by using multiple readings on 48 cases. Where serial studies were available in noncystic cases, a mock response analysis was used. RESULTS: The perimeter method had a reduced interreader and intrareader variability compared with the diameter method (using SD of differences): intrareader, 1.76 mL v 7.38 mL (P < .001); interreader, 2.51 mL v 9.07 mL (P < .001) for perimeter and diameter results, respectively. Of the 121 noncystic cases, 23 had serial data. In six (26.1%) of those 23, a classification difference occurred when the perimeter method was used versus the diameter method. CONCLUSION: Variability of measurements was reduced with the computer-assisted perimeter method compared with the diameter method, which suggests that changes in volume can be detected more accurately with the perimeter method. The differences between these techniques seem large enough to have an impact on grading the response to therapy.

Brain↗
PubMed2001

Mucosectomy vs. stapled ileal pouch-anal anastomosis in patients with familial adenomatous polyposis: functional outcome and neoplasia control.

PURPOSE: The tradeoff of neoplasia control for better function represented by a stapled ileal pouch-anal anastomosis is still controversial in patients with familial adenomatous polyposis. We compared outcomes after mucosectomy and hand-sewn ileal pouch-anal anastomosis with those after stapled ileal pouch-anal anastomosis in 119 patients with familial adenomatous polyposis who underwent surgery since 1983. METHODS: Age, gender, length of follow-up, complications, quality of life, incontinence, urgency, nighttime and daytime seepage, pad usage, necessity of ileostomy, and incidence of adenomas developing in pouch and anal transitional zone were recorded. RESULTS: There were 42 mucosectomy and 77 stapled patients who were followed up for an average of 5.8 and 3.6 years, respectively, with endoscopic surveillance. There was one postoperative death in the stapled group that prohibited long-term follow-up. Nine of 42 mucosectomy patients developed pouch adenomas vs. 8 of 76 in the stapled group. Six of 42 patients developed adenomas in the mucosectomized anal transitional zone in the mucosectomy group. Twenty-one of 76 patients developed adenomas in the anal transitional zone in the stapled group. All were managed with local procedures or further surveillance. One of 76 patients developed cancer in the residual low rectum; this required further resection. Patients with stapled anastomosis had better outcomes in every category. Differences in incontinence, daytime and nighttime seepage, pad usage, and avoidance of ileostomy were statistically significant. All patients with mucosectomy required ileostomy vs. only 40 of 77 patients with stapled anastomosis. CONCLUSION: Familial adenomatous polyposis patients with stapled ileal pouch-anal anastomosis have better functional outcome and can avoid temporary diversion. This should be balanced against a 28 percent incidence of adenomas in the anal transitional zone.

Adenoma↗
PubMed2001

The management of neoplastic colorectal obstruction with colonic endolumenal stenting devices.

BACKGROUND: Colonic endolumenal stenting (CELS) to treat obstructing colorectal neoplasms was first described in 1991. The aim of this study was to review the published world literature and make recommendations for its use in current clinical practice. METHODS: Suitable English language reports were identified using a Medline search. RESULTS: CELS can been successfully accomplished in 64% to 100% of obstructing malignant colonic lesions. Distal lesions are more common and theoretically more easy to stent although lesions within the ascending colon have been successfully managed. Minor complications include transient anorectal pain and rectal bleeding, however, significant complications of stent dislocation and colonic perforation are also well recognized. CONCLUSION: CELS can aid the palliative management of malignant colorectal obstruction. Its role in relieving obstruction prior to resection remains to be defined. Increasing experience has allowed the safe placement of stents and relief of obstruction of virtually any lesion throughout the large bowel.

Colorectal Neoplasms↗
PubMed2001

Function of a colonic J pouch continues to improve with time.

BACKGROUND: J pouch-anal anastomosis is thought to give superior functional results to straight coloanal anastomosis after rectal resection. Follow-up studies have suggested that this improvement is not maintained and that evacuatory difficulties may increase. METHODS: Some 119 consecutive patients had a coloanal anastomosis after resection for rectal carcinoma over 113 months, 62 with a J pouch and 57 with a straight coloanal anastomosis. Functional results were determined by patient questionnaire. The two groups were compared for the first and second 5-year intervals of study. RESULTS: Patients who had a J pouch had significantly better median Kirwan continence scores for the duration of the study and 5-9 years after surgery: 1 versus 2 (P = 0.05) and 1 versus 2 (P < 0.01), respectively. Some 5-9 years after surgery the median number of nocturnal bowel movements was significantly lower in patients who had a J pouch than in those with a straight coloanal anastomosis (0 versus 1; P = 0.02). Similarly, significantly better results were seen with regard to evacuation difficulties and urgency of defaecation. CONCLUSION: The function of the J pouch was superior to that of the straight coloanal anastomosis and appeared to improve with time.

Adenocarcinoma↗
PubMed2001

Utility of perfusion-weighted CT imaging in acute middle cerebral artery stroke treated with intra-arterial thrombolysis: prediction of final infarct volume and clinical outcome.

BACKGROUND AND PURPOSE: The goal of this study was to evaluate the utility of perfusion-weighted CT (PWCT) in predicting final infarct volume and clinical outcome in patients with acute middle cerebral artery (MCA) stroke. METHODS: Twenty-two consecutive patients with MCA stem occlusion who underwent intra-arterial thrombolysis within 6 hours of stroke onset had noncontrast CT and CT angiography with whole-brain PWCT imaging before treatment. Infarct volumes were computed from the initial PWCT and follow-up scans; clinical outcome was measured with the modified Rankin scale. RESULTS: Initial PWCT lesion volumes correlated significantly with final infarct volume (P=0.0002) and clinical outcome (P=0.01). For the 10 patients with complete recanalization, the relationship between initial and final lesion volume was especially strong (R(2)=0.94, P<0.0001, slope of regression line=0.92). For those without complete recanalization, there was progression of lesion volume on follow-up imaging (R(2)=0.50, P=0.01, slope of regression line=1.61). All patients with either initial PWCT lesion volumes >100 mL or no recanalization had poor outcomes (Rankin scores, 4 to 6). Mean admission NIH Stroke Scale scores and mean lesion volumes in the poor outcome group were significantly different compared with the good or fair outcome (Rankin scores, 0 to 3) group (21+/-4 versus 17+/-5, P=0.05, and 106+/-79 versus 29+/-37 mL, P=0.01). Patients with initial volumes <100 mL and partial or complete recanalization all had good (Rankin scores, 0 to 2) or fair (Rankin score, 3) outcomes. CONCLUSIONS: Lesion volumes on admission PWCT images approximate final infarct volume for patients with early complete recanalization of MCA stem occlusion. For those without complete recanalization, there is subsequent enlargement of lesion volume on follow-up. Initial PWCT lesion volumes also have predictive value; volumes >100 mL are associated with a poor clinical outcome. In these highly selected patients, initial PWCT lesion volume was a stronger predictor of clinical outcome than was initial NIH Stroke Scale score.

Acute Disease↗
PubMed2000

In-phase selective excitation of overlapping multiplets.

An editing experiment is presented that selects for a peak on the basis of its chemical shift and that of one of its scalar coupling partners. The selected multiplet is pure in-phase. The editing procedure can be used in conjunction with 1D TOCSY/HOHAHA and NOE measurements. The pulse sequence described is particularly suitable for small molecules; data is presented for Gramicidin S and dehydrotestosterone.

Magnetic Resonance Spectroscopy↗
PubMed2000

Criteria for nonsurgical management of subperiosteal abscess of the orbit: analysis of outcomes 1988-1998.

PURPOSE: On the basis of bacteriologic studies, we have recommended expectant observation with intravenous antibiotics for subperiosteal abscess (SPA) of the orbit in patients less than 9 years of age, given the absence of eight other specific surgical criteria. We attempted to test these recommendations with a prospective study. STUDY DESIGN: Prospective noncomparative case series. PARTICIPANTS: Forty patients younger than 9 years of age treated for orbital SPAs at the Childrens Hospital of Wisconsin from 1988 to 1998. METHODS: Specific management criteria were applied to a cohort of 37 orbital SPA patients. Three other orbital SPA patients under the age of 9, either ineligible for medical therapy or treated outside our guidelines, were also studied. Clinical data for all patients were reviewed and analyzed. MAIN OUTCOME MEASURES: Clinical resolution of the abscess, as evidenced by normal visual acuity, pupillary examination, motility, and globe position on the affected side. RESULTS: Eight patients met criteria for surgical treatment and underwent prompt drainage. Of the 29 patients for whom initial nonsurgical management was recommended, 27 (93.1%) SPAs cleared with expectant observation on intravenous antibiotics, and 2 patients defaulted to surgical intervention. All cases had successful clinical outcomes. CONCLUSIONS: In patients less than 9 years of age, orbital SPAs are likely to resolve without surgery, provided certain surgical criteria are absent.

Abscess↗
PubMed2000

Correlation of preoperative computed tomography and postoperative ocular motility in orbital blowout fractures.

PURPOSE: To determine a relationship between preoperative soft tissue disruption and postoperative ocular motility in orbital blowout fractures. METHODS: This retrospective cohort study reviewed 30 patients who met all criteria: retrievable coronal computed tomography (CT) scans; internal fractures of the orbital floor, with or without medial wall extension; preoperative diplopia; repair by a single surgeon; complete release of entrapped tissues; and postoperative binocular visual fields (BVFs). Motility outcomes were quantified by one group of the authors, who measured the vertical fusion within BVFs. Other authors analyzed CT scans, designating each fracture as either A or B, based on lesser or greater soft tissue distortion relative to the configuration of bone fragments. The interval between trauma and surgery was also determined. RESULTS: Among the 15 patients with a postoperative motility outcome poorer than the median (86 degrees or less), four (27%) had A fractures; 11 (73%) had B fractures. Among the 15 patients with an outcome better than the median (88 degrees or more), 10 (67%) had A fractures; five (33%) had B fractures. Differences were more defined away from the median. Among five patients with B fractures and better than the median result, three (60%) had surgical repair during the first week after injury. Among the 11 patients with B fractures and less than the median result, one (9%) had repair during the first week. CONCLUSIONS: Postoperative motility is influenced by soft tissue-bone fragment relationships. Whether the outcome can be altered by earlier surgery in selected cases will be determined by prospective studies.

Cohort Studies↗
PubMed2000

Cost-effectiveness of functional imaging tests in the diagnosis of Alzheimer disease.

PURPOSE: To evaluate the cost-effectiveness of functional neuroimaging in the work-up of patients at specialized Alzheimer disease clinics. MATERIALS AND METHODS: A decision model was used to calculate costs and benefits (in quality-adjusted life-years [QALYs]) that accrued to hypothetical cohorts of patients at presentation to an Alzheimer disease center. Sensitivity analysis was performed to examine the effects of diagnostic test characteristics, therapeutic efficacy, disease severity, and costs on cost-effectiveness. RESULTS: The incremental cost-effectiveness ratio of dynamic susceptibility contrast material-enhanced magnetic resonance (MR) imaging was $479,500 per QALY (compared with the usual diagnostic work-up), while visual or quantitative single photon emission computed tomography (SPECT) was dominated (higher costs, lower effectiveness) by the usual diagnostic work-up. These results depend critically on the sensitivity and specificity of the standard diagnostic work-up, the effectiveness of drug treatment, and the disease severity. Varying these parameters resulted in estimates of incremental cost-effectiveness for dynamic susceptibility contrast-enhanced MR imaging of $24,680 to $8.6 million per QALY. SPECT either was dominated by the usual diagnostic work-up or had cost-effectiveness ratios of $180,200 to $6 million per QALY. CONCLUSION: The addition of functional neuroimaging to the usual diagnostic regimen at Alzheimer disease clinics is not cost-effective given the effectiveness of currently available therapies.

Alzheimer Disease↗
PubMed2000

Hypoperfusion of inferior frontal brain regions in abstinent alcoholics: a pilot SPECT study.

OBJECTIVE: This pilot study evaluated hypotheses concerning the relationship between cerebral hypoperfusion and residual deficits in the functioning of frontal brain systems in abstinent long-term alcoholics. METHOD: The participants (N = 22) were 10 healthy, abstinent alcoholics (9 men) and 12 age-equivalent nonalcoholic controls (10 men). Cerebral blood flow was observed through the use of regionally specific computer-derived quantitative analysis of single photon emission computed tomography (SPECT) perfusion images. Measures of alcohol use, abstinence and neuropsychological functioning were also obtained to relate to SPECT findings. RESULTS: A positive relationship was observed between perfusion levels in the left inferior frontal brain region and years of sobriety. Alcoholics with less than 4 years of sobriety had significantly reduced left inferior frontal perfusion compared with both nonalcoholic controls and alcoholics having longer periods of sobriety. CONCLUSIONS: The findings support the hypothesis that frontal brain abnormalities in alcoholics may subside with extended abstinence.

Adult↗
PubMed2000

Decision-making: what tests to do? What choices to consider?

The treatment of recurrent colorectal cancer confronts the surgeon with a diagnostic and therapeutic challenge, particularly in cases involving the pelvis. Investigation and treatment in each case is tailored to the individual patient. Treatment is divided into those cases where an attempt at cure is possible and those where only palliation of symptoms is possible. This article seeks to help the surgeon confronted with this problem answer the following questions: Which patients with recurrent colorectal cancer are suitable for consideration of curative resection? What is the extent of disease recurrence? Is the disease resectable? The aim of this article is to offer advice in the logical and appropriate investigation and treatment of patients considered for curative or palliative therapy.

Colorectal Neoplasms↗
PubMed1999

Quantitative measurement of long range nuclear Overhauser enhancement.

Measurement of nuclear Overhauser enhancement is one of the mainstays of structural studies of molecules in solution. Measurements, particularly over long distances, are often compromised by spin diffusion. A robust and accurate method for measuring nuclear Overhauser enhancements that are largely free of spin diffusion effects is presented. The effects of using imperfect radiofrequency pulses are considered and experimental data are presented for Amphotericin B.

Magnetic Resonance Spectroscopy↗
PubMed1999

Acute dacryocystitis as a presenting sign of pediatric leukemia.

PURPOSE: To report acute dacryocystitis with preseptal cellulitis as the presenting sign of leukemia in a child. METHODS: Case report and literature review. RESULTS: During the initial evaluation of a 17-month-old child with epiphora, left lower eyelid swelling, and a tender left medial canthal mass, a complete blood cell count demonstrated pancytopenia. Bone marrow biopsy disclosed replacement of normal cellular architecture with a dense infiltrate of leukocyte blast forms. DNA analysis disclosed a translocation between chromosome 10 and 11, consistent with the diagnosis of nonlymphocytic leukemia. Although the adjacent lower eyelid cellulitis responded to intravenous antibiotics, lacrimal sac distention decreased only after chemotherapy was initiated. CONCLUSIONS: Dacryocystitis with preseptal cellulitis can be a presenting sign of leukemia. This blood malignancy should be considered in patients whose leukocyte counts do not correlate with their clinical presentation.

Acute Disease↗
PubMed1999

Orbital vascular malformations: a consensus statement on terminology and its clinical implications. Orbital Society.

PURPOSE: Orbital venous anomalies and lymphangiomas have been generally classified on morphologic grounds. However, conflicting concepts of these lesions have hampered scientific dialogue and confused clinicians, with occasionally serious consequences for patients. As a step toward uniform nomenclature and better communication, a consensus on the terminology of orbital vascular malformations was sought among the members of the Orbital Society. METHODS: A classification of orbital vascular malformations based on their hemodynamic relationships, as revealed by clinical and imaging features, was presented, discussed, and adopted at the 1998 Annual Meeting of the Orbital Society. A consensus statement was drafted and distributed to all members. The statement was then modified in accordance with members' responses, which included minor stylistic recommendations but no substantive dissent. RESULTS: Orbital vascular malformations may be classified according to their hemodynamic relationships as no flow, venous flow, and arterial flow lesions. Assignment to each group is based on pertinent clinical and imaging criteria. Mixed forms with both venous and no flow components are grouped within the venous flow category to emphasize the clinical importance of that relationship. CONCLUSIONS: A hemodynamic classification of orbital vascular malformations emphasizes features most germane to their management. It should reduce the clinical confusion resulting from purely morphologic differentiation. Widely accepted definitions may allow a better comparison of therapeutic protocols for these troublesome lesions.

Arteries↗