Biomedical subjects

J T Wilson

Publications and source records attributed to J T Wilson.

At least 37 records · Page 2Linked to original sources

PubMed1998

Structured interviews for the Glasgow Outcome Scale and the extended Glasgow Outcome Scale: guidelines for their use.

The Glasgow Outcome Scale (GOS) is the most widely used outcome measure after traumatic brain injury, but it is increasingly recognized to have important limitations. It is proposed that shortcomings of the GOS can be addressed by adopting a standard format for the interview used to assign outcome. A set of guidelines are outlined that are directed at the main problems encountered in applying the GOS. The guidelines cover the general principles underlying the use of the GOS and common practical problems of applying the scale. Structured interview schedules are described for both the five-point GOS and an extended eight-point GOS (GOSE). An interrater reliability study of the structured interviews for the GOS and GOSE yielded weighted kappa values of 0.89 and 0.85, respectively. It is concluded that assessment of the GOS using a standard format with a written protocol is practical and reliable.

Adolescent↗

PubMed1998

Analyzing outcome of treatment of severe head injury: a review and update on advancing the use of the Glasgow Outcome Scale.

The Glasgow Outcome Scale (GOS), two decades after its description, remains the most widely used method of analyzing outcome in series of severely head-injured patients. This review considers limitations recognized in the use of the GOS and discusses a new approach to assessment, using a structured questionnaire-based interview. Assignments can be made to an extended eight-point scale (GOSE) as well as the original five-point approach-in each case, with a high degree of interobserver consistency. The assignments are coherent with the principles of the World Health Organization classification of impairments, disabilities, and handicaps, and their validity is supported by strong associations with the results of neuropsychological testing and assessment of general health status. The need to allow for disability existing before injury, issues concerning the time of assessment after injury, and subdivisions of the scale into "favorable" and "unfavorable" categories are discussed. It is concluded that, in its improved structured format, the Glasgow Outcome Scale should remain the primary method of assessing outcome in trials of the management of severe head injury.

Craniocerebral Trauma↗

PubMed1998

Hollow visceral injury and blunt trauma.

BACKGROUND: The incidence of hollow viscus injury (HVI) after blunt trauma (BT) is variable, and differences between children and adults have not been well described. The purpose of this study is to determine the age-group-related incidence and characteristics of BT-associated HVI as well as the clinical markers and consequences of delayed diagnosis. METHODS: A 9-year trauma registry review of all patients with HVI. RESULTS: A large sample of patients (19,621) with BT were evaluated (2,550 < or = 14 years old; 17,070 > 14 years old). One hundred thirty-nine of 17,070 (0.8%) adults had HVI compared with 27 of 2,550 (1%) children. HVI occurred more frequently in the duodenum in children (11 of 27) compared with adults (17 of 139) (p < 0.05). Among patients with abdominal wall ecchymosis, 13.5% of children had HVI compared with 10.6% of adults. Delays in diagnosis of HVI occurred in 9 of 27 children compared with 10 of 139 adults (p < 0.0 5). Delayed diagnosis was associated with increased abdominal septic complications in both children (4 of 9) and adults (2 of 10) compared with diagnosis at presentation (p < 0.05). CONCLUSION: HVI occurs with a similar low frequency in both children and adults. Duodenal injuries are more common in pediatric BT patients. Abdominal wall ecchymosis is associated with increased HVI but is less predictive of HVI than previously described. Contrary to previous reports, delays in diagnosis are associated with increased morbidity.

Abdominal Injuries↗

PubMed1998

Assessing disability after head injury: improved use of the Glasgow Outcome Scale.

OBJECT: The Glasgow Outcome Scale (GOS) is widely used to assess outcome after head injury, but is recognized as having a number of shortcomings that are highlighted and investigated in this study. The authors pursued two goals: 1) investigating the practicality of using a standard set of questions as part of a structured interview to assign GOS scores, and 2) studying the role of preinjury problems in confounding postinjury assessment of disability. METHODS: Several of the major limitations of the GOS appear to arise from the use of a format that encourages impressionistic ratings. In the present study the authors examined the use of a standard interview for assessing the GOS covering five areas of social disability. Ratings were made for 80 head-injured patients. The results show that the rating based on the GOS provides an assessment of disability that is more complete than that given by an alternative scale of functional disability (Disability Rating Scale [DRS]) and much more complete than an assessment of physical disability (Barthel Activities of Daily Living [ADL] index). A measure of preinjury dependency was made revealing that, within this sample, 20% of patients required supervision in basic ADL before their injury. CONCLUSIONS: Assignment of GOS scores based on information obtained using a structured interview format provides a more comprehensive assessment of disability than using the DRS or the ADL index. There is a need to standardize attitudes about preinjury dependency in assessing disability after head injury.

Adolescent↗

PubMed1997

Implementation of natural attenuation at a JP-4 jet fuel release after active remediation.

After eighteen months of active remediation at a JP-4 jet-fuel spill, a residual of unremediated hydrocarbon remained. Further site characterization was conducted to evaluate the contribution of natural attenuation to control exposure to hazards associated with the residual contamination in the subsurface. Activities included the detailed characterization of ground-water flow through the spill; the distribution of fuel contaminants in groundwater; and the analysis of soluble electron acceptors moving into the spill from upgradient. These activities allowed a rigorous evaluation of the transport of contaminants from the spill to the receptor of groundwater, the Pasquotank River. The transport of dissolved contaminants of concern, that is benzene, toluene, ethyl benzene, xylene isomers (BTEX) and methyl-tertiary-butyl ether (MTBE), into the river from the source area was controlled by equilibrium dissolution from the fuel spill to the adjacent groundwater, diffusion in groundwater from the spill to permeable layers in the aquifer, and advective transport in the permeable layers. The estimated yearly loading of BTEX compounds and MTBE into the receptor was trivial even without considering biological degradation. The biodegradation of hydrocarbon dissolved in groundwater through aerobic respiration, denitrification, sulfate reduction, and iron reduction was estimated from changes in ground-water chemistry along the flow path. The concentrations of target components in permanent monitoring wells continue to decline over time. Long term monitoring will ensure that the plume is under control, and no further active remediation is required.

Biodegradation, Environmental↗

PubMed1997

SPECT, CT, and MRI in head injury: acute abnormalities followed up at six months.

Neuroimaging with single photon emission computed tomography (SPECT) using the cerebral blood flow tracer 99Tc(m)-HMPAO has been used to study acute functional alterations after head injury and residual abnormalities at six month follow up in 32 patients. Comparison has been made with anatomical abnormalities defined acutely with CT and on follow up with MRI. SPECT showed slightly more abnormalities than CT in the acute phase (49 regions of abnormally low tracer uptake on SPECT and 45 lesions on CT). Twenty two of the acute SPECT abnormalities were in normal regions on CT. At follow up MRI showed more abnormalities than SPECT (30 on SPECT and 48 on MRI). Ten of the SPECT deficits were in regions with normal MRI. Comparison of the intensity of late and early SPECT deficits showed that only four early deficits deteriorated whereas 28 improved. Only five of 27 lesions seen on both acute SPECT and CT resolved compared with 16 of 22 lesions seen on SPECT but not on CT. Regions of abnormally high tracer uptake were detected in the acute stage in five of the patients. No high focal uptake was evident on follow up. Ten patients with a residual SPECT abnormality and eight with residual MRI lesions were graded clinically in the upper band of good recovery.

Adolescent↗

PubMed1997

The relation between MRI neuroactivation changes and response rate on a word-fluency task.

This study investigated the functional magnetic resonance imaging response of the left premotor cortex activated during a word-fluency task. We hypothesized that a cortical region crossing the boundary between Brodmann's areas 44 and 6 would show bias toward output during word generation (i.e., the more words generated the greater the activation), supporting the view that this region is involved in the motor planning of speech rather than the search component of word generation. Ten participants were shown letters with different word-generational frequencies, and these were correlated with magnetic resonance signal changes over the region. Significant differences (p = .05) were found in the neuroactivation changes between groups of letters associated with high and low overt frequencies. This finding supports our hypothesis concerning the role of areas 44 and 6 in word-generation tasks.

Journal Article↗

PubMed1996

Multiple intradural spinal lipomata with intracranial extension.

An intradural, intramedullary lipoma originating within the upper cervical cord with significant extension into the posterior fossa is reported in an infant. Two additional lipomas were found in the lumbar region. This constellation of findings represents the first description of multiple intradural, intramedullary spinal lipomas with extensive intracranial involvement.

Cerebral Ventricle Neoplasms↗

PubMed1995

Spinal anesthesia for repair of meningomyelocele in neonates.

The use of spinal anesthesia for meningomyelocele repair in neonates has received minimal attention. Spinal anesthesia may lessen the stress response to surgery and decrease postoperative respiratory complications. We therefore examined the efficacy of spinal anesthesia in 14 neonates requiring repair of lumbar or sacral meningomyelocele. All neonates were positioned prone with a small chest roll. Hyperbaric 0.5% tetracaine with epinephrine was injected into the caudal end of the meningomyelocele sac. If necessary, supplemental tetracaine was administered directly into the intrathecal space by the surgeon during the operation. Blood pressure, heart rate, and oxyhemoglobin saturation were measured throughout surgery. Neonates were monitored with transthoracic impedance apnea monitors, electrocardiogram (ECG), and pulse oximetry for 36 h after surgery. Spinal anesthesia was successful in all cases. Seven patients received one supplemental tetracaine injection; one patient received two supplemental injections. Arterial blood pressure decreased an average of 5 mm Hg with the largest decrease being 10 mm Hg. Two postoperative respiratory events occurred in the first 8 h after surgery. Both neonates had received intraoperative midazolam for sedation. Neurologic function was assessed pre- and postoperatively. Twelve patients had no change in neurologic function after surgery, while two infants demonstrated improved function. We conclude that spinal anesthesia can be safely used for meningomyelocele repair.

Anesthesia, Spinal↗

PubMed1995

U83836E reduces secondary brain injury in a rabbit model of cryogenic trauma.

Oxygen-derived free radicals have been implicated in secondary brain injury after head trauma. Although oxygen-free radicals may be derived from multiple sources, the activation and accumulation of neutrophils in areas of brain injury is a potential source of deleterious inflammatory mediators, including free radicals, which may exacerbate the primary insult. Neutrophils may also impede the cerebral microcirculation by congestion and occlusion of postcapillary venules. The lazaroid U83836E is a potent-free radical scavenger that inhibits lipid peroxidation. U83836E was studied in a cryogenic model of cerebral injury in pretreatment paradigm. Fifteen rabbits received a unilateral cryogenic brain lesion. Six animals received U83836E, and nine animals received vehicle only. Arterial blood gases, hematocrit, temperature, and mean arterial pressure were controlled in physiologic range throughout the experiment. Intracranial pressure was continuously monitored. Lesion size was determined by triphenyltertrazolium chloride staining and planimetric image analysis. Neutrophil aggregation and oxygen-free radical generation was assessed in whole blood by impedance aggregometry and simultaneous luminol-mediated chemiluminescence, respectively. Myeloperoxidase assay was used to determine neutrophil accumulation within the brain. Elevations in intracranial pressure from baseline values were significantly greater in the untreated (control) animals at all time points (p < 0.0001). Mean lesion size (% hemisphere +/- SEM) was significantly reduced in animals receiving U83836E (4.41 +/- 0.64, n = 6) when compared with controls (15.09 +/- 2.28, n = 9, p < 0.001). A reduction in both the release of oxygen-free radicals and in neutrophil aggregation following the cryogenic injury in the U83836E animals correlated with a smaller lesion volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Pharmacotherapy of depression in children.

Depression can interfere with the overall functioning of children and adolescents. It can impair normal cognitive and social development. The use of antidepressant medications in children and adolescents has grown in the past decade. Newer antidepressant agents, the selective serotonin reuptake inhibitors, appear very promising, but their safety and efficacy have not been established for children. This review focuses on depression and the design of studies for its treatment with newer antidepressant drugs in children.

Adolescent↗

PubMed1995

Neuropsychological consequences of two patterns of brain damage shown by MRI in survivors of severe head injury.

Two subgroups of patients were identified from 48 patients with traumatic head injury who had MRI during the acute stage: (a) those with severe diffuse injury--six patients with lesions in both the corpus callosum and the brain stem; (b) those with severe focal injury--16 patients with extensive frontotemporal lesions. Most patients with diffuse injury were in a coma on admission to hospital, whereas most patients with focal injury were out of coma. Duration of post-traumatic amnesia was prolonged in both groups. Patients were followed up at six months after injury, when a battery of neuropsychological tests was given. Patients with both diffuse and focal patterns of injury were impaired by comparison with controls on a range of measures, including tests of memory and attention. The findings contrast with the view that diffuse injury is of much greater importance than focal injury in determining outcome after head injury.

Adolescent↗

PubMed1995

Primary diffuse chiasmatic germinomas: differentiation from optic chiasm gliomas.

Primary germ cell tumors confined to the optic nerves and chiasm without suprasellar extension are uncommon. These tumors appear similar to chiasmatic gliomas on both computed tomography and magnetic resonance imaging, potentially resulting in treatment errors if the diagnosis is based on radiologic criteria alone. Unlike chiasmatic gliomas, suprasellar germinomas characteristically present with a clinical triad of endocrine abnormalities, diabetes insipidus, and visual complaints. We report the case of a 9-year-old boy who presented with a 5-month history of fatigue, 16-pound weight gain, polydipsia, polyuria, visual complaints, and intermittent headache. Imaging studies demonstrated findings consistent with a glioma of the chiasm with infiltration into the optic tracts. At surgery, the chiasm and optic tracts were diffusely enlarged with no other suprasellar abnormalities. Biopsy specimens were characteristic of germ cell tumor. Based on this result, the patient received a treatment regimen different from that used at our institution for chiasmatic gliomas. We feel it is imperative to biopsy chiasmatic lesions that radiologically appear to be gliomas if symptoms do not adhere to the classical clinical presentation.

Biopsy↗

PubMed1995

Neural network of structures in which GABAB receptors regulate absence seizures in the lethargic (lh/lh) mouse model.

In previous work we have shown that GABAB receptors are required for expression of absence seizures in the lethargic (lh/lh) mouse model; that lh/lh mice have increased numbers of GABAB binding sites compared to nonepileptic littermates (designated +/+); and that the magnitude of the increased number of GABAB receptors in lh/lh mice correlated positively with the frequency of absence seizures. We performed this study to delineate the neural network in which GABAB receptors regulate absence seizures in lh/lh mice. We designed three successive screens which had to be passed by a candidate neuronal population before it could be considered a member of the neural network in which GABAB receptors regulate absence seizures. First, the neuronal populations in lh/lh mice had to have enriched GABAB binding sites compared to homologous populations in matched nonepileptic controls; baclofen-displaceable 3H-GABA binding was measured in autoradiograms for this screen. Second, the candidate populations had to generate spike-wave discharges (SWDs) during absence seizures in lh/lh mice; bipolar recording electrodes implanted into candidate neuronal structures were used in this screen. Third, the candidate populations had to demonstrate GABAB receptor-mediated regulation of absence seizures in lh/lh mice; microinjections of a GABAB agonist [(-)-baclofen] and antagonist (CGP 35348) were used for this screen. In this study we found that anterior ventral lateral thalamic nucleus (VLa), nucleus reticularis thalami (NRT), nucleus reuniens (RE) passed all three screens, and hence are members of the neural network in which GABAB receptors regulate absence seizures in lh/lh mice.

Animals↗

PubMed1995

Routine prophylactic vena cava filter insertion in severely injured trauma patients decreases the incidence of pulmonary embolism.

BACKGROUND: Trauma patients are at increased risk for venous thromboembolism despite routine prophylaxis. A five-year retrospective review of pulmonary embolism at the Medical Center Hospital of Vermont showed that four types of injuries (head injuries, spinal cord injuries, complex pelvic fractures, and hip fractures) accounted for 92 percent of pulmonary emboli in patients on the trauma service. STUDY DESIGN: Beginning July 1991, all patients who met criteria for a high-risk injury (excluding hip fractures) had prophylactic vena cava filters inserted percutaneously in the radiology suite. Weekly impedance plethysmography was performed for the detection of deep vein thrombosis. Following discharge, abdominal duplex ultrasound was performed at one month, six months, and yearly to check filter position and patency. RESULTS: To date, a total of 63 patients, or 2 percent of the total trauma population, had prophylactic vena cava filters inserted. There were 19 (30 percent) deep vein thromboses in this population of patients and one patient had a pulmonary embolism (1.5 percent). Overall there was significant (chi-square, p < 0.00072) reduction of pulmonary embolism on the trauma service compared to the historical controls. Follow-up examination with abdominal duplex ultrasound showed a 30-day patency rate of 100 percent and a one- and two-year patency rate of 96.1 +/- 3.8 percent by life-table analysis. CONCLUSIONS: We concluded that prophylactic vena cava filters are efficacious in decreasing the risk of pulmonary embolism in high-risk trauma patients.

Adult↗

PubMed1994

The effect of AGM-1470 in an improved intracranial 9L gliosarcoma rat model.

Angiogenesis is a process fundamental to the growth of many solid tumours. Agents that inhibit angiogenesis may have a role in preventing tumour growth. AGM-1470, a synthetic analogue of fumagillin, has been shown to inhibit tumour growth in several extracranial solid tumour models. Its use has been reported to have minimal side effects. No studies have been reported using AGM-1470 in the treatment of an intracranial tumour. To determine the effect of AGM-1470 on an intracranial glial tumour, we used an improved implantation technique to place 80,000 9L tumour cells into the right caudate nucleus of 25 male Fischer 344 rats. Starting on the first post-implantation day, 12 animals received 30 mg kg-1 AGM-1470 via intraperitoneal injection every other day until death. Thirteen control animals received vehicle only. Evidence of intracranial tumour was apparent in 22/23 animals (96%). All animals treated with AGM-1470 experienced a progressive and significant weight loss when compared to controls. At day 17, treated animals retained 80.0 +/- 2.2% of their initial weight, (mean +/- SD) compared to 100.9 +/- 3.6% for controls (p = 2.25 x 10(-12); student's t-test). AGM-1470 had no effect on survival. Median survival in the treatment group was 24.5 days compared to 25 days in the controls (p = 0.95; Mann-Whitney). AGM-1470, although promising in extracranial tumour models, may not be as effective in controlling the growth of intracranial tumours, and its use is not without significant systemic effects. More studies are needed before this drug is used in human brain tumour trials.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Post-traumatic amnesia: still a valuable yardstick.

Records of coma and post-traumatic amnesia (PTA) were collected for a group of 38 patients with closed head injury. The results confirmed earlier studies indicating that patients may have short or negligible coma but report prolonged PTA. Comparison of eight patients with prolonged PTA (> 7 days) and short coma (< 6 hours) with the rest of the group on MRI in the acute stage showed that these patients had significantly more extensive hemispheric damage. In the group as a whole both coma and PTA were related to the number of areas in central brain structures in which lesions were detected, but only PTA was significantly related to the number of hemispheric areas in which lesions were found. It is concluded that although both coma and PTA are related to brain damage they reflect disparate patterns of lesions. Assessment of PTA can thus provide additional information concerning severity of injury.

Adolescent↗

PubMed1994

Cost and survival analysis of metastatic cerebral tumors treated by resection and radiation.

The surgical treatment of metastatic brain tumors remains controversial, primarily because of the limited prognosis of patients with metastatic cancer. The cost effectiveness of even standard therapies is of increasing concern to third-party payers. We reviewed the records of patients who had a single metastatic brain tumor resected at the Medical Center Hospital of Vermont (a referral center in a rural state) since cost data recording began. The 32 patients ranged in age from 35 to 77 years, with a 2.2:1 female-to-male ratio. Thirty-four percent of tumors originated in the lung, 15.6% were renal, 12.5% were breast, 12.5% were gynecological, 9.4% were gastrointestinal, and 9.4% were ultimately of unknown origin. Thirty-one tumors were completely resected; 30 patients were irradiated, most after surgery (mean dose, 3,908 +/- 1,250 cGy). Karnofsky scores improved from 80 +/- 11 to 88 +/- 16 postoperatively (P = 0.0038, one-tailed paired t-test). Patients were hospitalized an average of 8.22 +/- 6.26 days postoperatively, with total operative and postoperative charges of $19,190 +/- 5,684, noninclusive of radiotherapy. The expected median survival of all patients was 26 months (Kaplan-Meier estimate). The presence of disseminated disease was not significantly correlated with survival (P = 0.237). The number of postoperative days was more for patients with disseminated disease (P = 0.0274), but not for patients with infratentorial tumors (P = 0.6991). Age higher than the median was not correlated with an increased number of postoperative days (P = 0.1366) nor was a preoperative Karnofsky score of 70 or less (P = 0.1382).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗