Search PubMed⌕ Search

Biomedical subjects

D M Long

Publications and source records attributed to D M Long.

At least 91 records · Page 5Linked to original sources
PubMed1991

Failed back surgery syndrome: 5-year follow-up in 102 patients undergoing repeated operation.

The indications for repeated operation in patients with persistent or recurrent pain after lumbosacral spine surgery are not well established. Long-term results have been reported infrequently, and in no case has mean follow-up exceeded 3 years. We report 5-year mean follow-up for a series of repeated operations performed between 1979 and 1983. Patient characteristics and modes of treatment have been assessed as predictors of long-term outcome. One hundred two patients with "failed back surgery syndrome" (averaging 2.4 previous operations), who underwent a repeated operation for lumbosacral decompression and/or stabilization, were interviewed by a disinterested third party a mean of 5.05 years postoperatively. Successful outcome (at least 50% sustained relief of pain for 2 years or at last follow-up, and patient satisfaction with the result) was recorded in 34% of patients. Twenty-one patients who were disabled preoperatively returned to work postoperatively; 15 who were working preoperatively became disabled or retired postoperatively. Improvements in activities of daily living were recorded, overall, as often as decrements. Loss of neurological function (strength, sensation, bowel and bladder control) was reported by patients more often than improvement. Most patients reduced or eliminated analgesic intake. Statistical analysis (including univariate and multivariate logistic regression) of patient characteristics as prognostic factors showed significant advantages for young patients and for female patients. Favorable outcome also was associated with a history of good results from previous operations, with the absence of epidural scar requiring surgical lysis, with employment before surgery, and with predominance of radicular (as opposed to axial) pain.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMed1991

Failed back surgery syndrome.

The failed back or postlaminectomy syndrome is obviously multidimensional. Failure of therapy may result from structural abnormalities in the back, psychosocial influences, or a combination of both. The causes of back pain are largely unknown. Correlations with diagnostic studies are uncertain. The lack of precise diagnoses is reflected in a multiplicity of nonspecific treatments, mostly of unproven value. Our current disability-litigation system adds greatly to the problem. Patients are rewarded for nonfunction. Some physicians become advocates for patients, others for insurance carriers and employers. Decisions concerning appropriate treatment are often made by patients, attorneys, the disability determination system, employers, and judges for extraneous reasons, which include financial gain or personal bias and often reflect lack of current information. Even when correct decisions are made, there is a lack of adequate programs for diagnosis and comprehensive treatment of these individuals. The failed back syndrome is not likely to disappear quickly. Large numbers of these patients require care. The best available evaluation includes thorough, but not overly minute investigation using the best current imaging techniques. These studies combined with the history and physical examination should provide a reasonably accurate assessment of the patient's condition. Concomitant evaluation of psychosocial issues is mandatory, and those who treat these patients without understanding the importance of the various comorbidities discussed are likely to be detrimental. Reparative surgery has real, but limited use. Nerve root compression and instability are the only two conditions demonstrated to be correctable at the present time. However, even when a potentially remediable lesion is found, these patients should undergo a reasonable attempt at physical rehabilitation with attention to both local factors and general function. The best data available today suggest that most of the patients suffering from failed back syndrome are incapacitated by psychiatric, psychologic, and social/vocational factors, which relate to the back complaint only indirectly. Those currently suffering from this problem can be best treated by comprehensive programs that address these complex psychosocial issues. New additions to this category can be reduced by rigorous attention to physical abnormalities, so that surgery is undertaken only for clear indications, and appreciation of the importance of the psychologic aspects of disability from low back pain. The smaller group suffering principally from physical abnormalities can be improved by reparative surgery or pain-relieving procedures if intensive conservative rehabilitation efforts fail. All surgical procedures fail occasionally, and as long as there is a need for reparative surgery, some patients will fail to benefit or be worsened by the procedures.(ABSTRACT TRUNCATED AT 400 WORDS)

Back Pain↗
PubMed1990

Effects of the arachidonate lipoxygenase inhibitor BW755C on traumatic and peritumoural brain oedema.

The abstract BW755C is a novel non-steroidal anti-inflammatory agent. It inhibits synthesis of prostaglandins and leukotrienes by inhibition in the cyclooxygenase and lipoxygenase pathways of arachidonic acid metabolism. Cold injury induced vasogenic oedema was produced in 18 cats. The animals were sacrificed at six and twenty-four hours. One group was treated with BW755C. Seventeen white rabbits bearing an experimental brain tumour VX-2 carcinoma were treated for five consecutive days from the eight day after tumour injection to the thirteenth day. Untreated tumour bearing rabbits were used as control. Brain water content was measured by specific gravity method. BW755C did not reduce the water content following cold injury. There was no effect upon peritumoural oedema. The use of this novel blocking agent with diffuse effects in the arachidonic cascade was not beneficial for the reduction or prevention of brain oedema.

4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz↗
PubMed1990

Comparative effects of direct and indirect hydroxyl radical scavengers on traumatic brain oedema.

The effects of dimethyl sulfoxide (DMSO) and dimethylthiourea (DMTU) and deferoxamine (DFO) were investigated in cats during a standard cortical freezing method for the production of vasogenic brain oedema. Hydroxyl radical scavenging activity was studied by electron spin resonance assay using DMPO as the trap. The hydroxyl radical spin adduct was extinguished by DFO and a large dose of DMTU. Evans blue dye extravasation was reduced in DFO and DMSO treated groups as well. DFO appears to be an effective agent for the prevention of cold induced oedema. DMSO and DMTU are direct hydroxyl radical scavengers. These studies suggest that scavenging the hydroxyl radicals has a beneficial effect in the treatment of traumatic brain oedema.

Animals↗
PubMed1990

Oxygen free radicals in the genesis of peritumoural brain oedema in experimental malignant brain tumours.

Disruption of blood brain barrier with increased vascular permeability is associated with genesis of peritumoural oedema. Oxygen free radicals play a role in increased vascular permeability. Recent studies have suggested that tumour cells can produce superoxide radicals and free radical scavengers such as superoxide dismutase (SOD) and catalase in tumour cells are impaired. In this study, we investigated the role of oxygen free radicals in the genesis of peritumoural brain oedema in experimental malignant brain tumours using V x 2 carcinoma cells and 9L glioma cells. In vitro data indicate that the V x 2 carcinoma cell and the 9L glioma cells produce superoxide radicals detected by nitroblue tetrazolium. Electron spin resonance spectroscopy using DMPO as a spin trap demonstrated that SOD activity was significantly lower in subcutaneous larger 9L glioma tumours than in normal brains and 9L glioma brain tumours. In the subcutaneous tumours, SOD activity was lower in the central portion of the tumour than in the peripheral portion of the tumour. In conclusion, we are not sure whether oxygen free radicals are major causative factors of peritumoural brain oedema, but the demonstration of oxygen free radicals in brain tumour cells needs further investigation.

Animals↗
PubMed1990

Acute management of intracranial hemorrhage in patients receiving thrombolytic therapy: case reports.

Intracranial hemorrhage is an uncommon complication of antithrombotic therapy. We present two patients who suffered life-threatening intracranial bleeding as a complication of thrombolytic/anticoagulant treatment. Early diagnosis and treatment appear to be crucial factors for survival. We suggest an approach to perioperative management for intracranial hemorrhage resulting from antithrombotic therapy.

Aged↗
PubMed1990

The molecular basis of brain injury and brain edema: the role of oxygen free radicals.

This review article outlines basic concepts and pathophysiological aspects of the chemistry of oxygen free radicals in all forms of brain injury and brain edema. Recent experimental studies have demonstrated that oxygen free radicals may be important mediators of brain injury and brain edema, and pharmacological antagonism of oxygen free radicals shows beneficial therapeutic results. A number of fundamental questions need to resolved, and advanced techniques for detecting oxygen free radicals will be needed. No clinical data are available, but oxygen free radical scavengers may possibly become a critical therapeutic modality for brain injury and brain edema.

Animals↗
PubMed1990

Surgical resection of intrinsic brain stem lesions: an overview.

A major limitation to the effective treatment of intrinsic mass lesions of the brain stem has been the inability to clearly define the pathological anatomy radiographically. The improved soft tissue resolution offered by magnetic resonance imaging, as compared with axial computed tomography, now makes it possible not only to accurately distinguish anatomical relationships, but also to predict the pathological nature of the lesion. Accordingly, we have been encouraged to pursue a more aggressive approach to intrinsic lesions of the brain stem that appear well circumscribed on magnetic resonance imaging scan. The object of this paper is to report the successful treatment of four intrinsic lesions of the brain stem and to present an overview of the relevant published experience.

Adult↗
PubMed1990

Stabilization of nitrate reductase in maize roots by chymostatin.

Nitrate reductase (NR) in maize (Zea mays cv W64A x W182E) roots has been stabilized in vitro by the addition of chymostatin to extraction buffer. Contrary to previous observations, levels of NR were higher in the mature root than in root tip sections when chymostatin was included in the extraction buffer. Two forms of NR were identified, an NADH monospecific NR found mainly in the 1cm root tip and an NAD(P)H bispecific NR found predominantly in mature regions of the root. During the first 10 days of seedling growth, NR activity in the root ranged from 50 to 80% of the activities found in the leaf (a maximum of 2.4 micromoles NO(-) (2) produced per hour per gram fresh weight was measured at 4 days).

Journal Article↗
PubMed1990

Uncommon tumors of the skull base and uncommon approaches to them.

The recognition of a number of uncommon tumors of the skull base is now relatively simple because of three-dimensional computed tomography and magnetic resonance imaging with enhancement. The radiographic classification of these tumors is reviewed, and their treatment is discussed. Although the basic approach to these tumors is the same--radical surgery with decompression of neural and vascular structures--the authors present various operative techniques for gaining access to and removing these tumors. They also examine the role of radiotherapy in supplementing surgical treatment.

Craniotomy↗
PubMed1990

Tumors of the skull base.

Recognition of the many benign and malignant tumors that occur in the skull base is now simple, given three-dimensional CT scanning and MRI with enhancement. Recent developments in surgical technique have allowed these tumors to be approached, but only in the past two to three years has radical surgery been possible.

Chondroma↗
PubMed1990

Effect of superoxide dismutase in cats with cold-induced edema.

We evaluated the potential role of SOD, an oxygen free radical scavenger, as a probe to cover the trigger period of injury and the prolonged period of development of edema in vasogenic brain edema. Vasogenic brain edema was produced in 34 cats by a standardized cortical freezing lesion. Brain edema and the disruption in the BBB were assessed by SG measurement and spread of Evans blue by planimetry. Detection of superoxide radicals was studied by topical application of NBT within the cranial window. Animals were separated into two groups: (a) controls; and (b) two SOD-treated groups--A was pretreated with 10,000 U/kg PEG-SOD intraperitoneally and sacrificed at 24 and 48 hr after lesions, and B received both a bolus injection of free SOD (4 mg/kg) and then 1 mg/kg/min for 20 min after the lesion and was sacrificed 6 hr later. Our preliminary data indicate that superoxide radicals were detected in the brain after cold-induced injury, but free and PEG-SOD had no beneficial effect on vasogenic brain edema produced by cold-induced injury. It is concluded that intracellular uptake of SOD might be necessary for an effect in the treatment of cold-induced brain edema.

Animals↗
PubMed1990

Effect of superoxide dismutase in rabbits with peritumoral edema.

We evaluated the effect of SOD, an oxygen-free radical scavenger, on peritumoral edema in 20 rabbits. The VX2 carcinoma was transplanted to the brains of these New Zealand white rabbits. Detection of superoxide radicals in vitro was performed by incubating the VX2 tumor cells with NBT. For evaluation of the effect of SOD on the tumor cells, they were treated with free SOD or PEG-SOD before and after incubation with NBT. The animals were separated into three groups: group 1, control group; group 2, SOD-untreated tumor group; group 3, two SOD-treated groups-group 3a, treated with 10,000 U/kg PEG-SOD on day 1 and 4 after tumor transplantation and sacrificed on day 13; group 3b, treated with 10,000 U/kg PEG-SOD on day 7 and 10 and sacrificed on day 13. Brain edema was assessed by SG measurement. Our preliminary in vitro data indicated that the VX2 carcinoma produced superoxide radicals but that free SOD and PEG-SOD could not penetrate into tumor cells nor inhibit superoxide radicals. In vivo data also indicated that PEG-SOD failed to reduce peritumoral edema. It was concluded that intracellular uptake or penetration of SOD must first be achieved before any effect on peritumoral edema can be assessed.

Animals↗
PubMed1990

Pseudarthrosis of the cervical spine after anterior arthrodesis. Treatment by posterior nerve-root decompression, stabilization, and arthrodesis.

Nineteen consecutive patients who had a symptomatic pseudarthrosis after a failed anterior cervical arthrodesis were treated by a posterior nerve-root decompression and arthrodesis. The indications for the operation were radiculopathy in the absence of myelopathy and evidence of a pseudarthrosis on lateral flexion and extension radiographs. The average duration of follow-up was forty-four months (range, twenty-four to fifty-four months). A solid fusion was achieved in all patients, and the radiculopathy was relieved in all but one. The motor weakness that had been present in four patients preoperatively resolved completely.

Adult↗