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Biomedical subjects

W C Welch

Publications and source records attributed to W C Welch.

35 records · Page 2Linked to original sources
PubMed1997

Isolated deep cerebral venous thrombosis treated by direct endovascular thrombolysis.

BACKGROUND: Isolated thrombosis of the deep cerebral venous system is very rare and is associated with a poor prognosis. Antithrombin III (AT III) deficiency is a disorder of hypercoagulability associated with deep venous thrombosis and recurrent pulmonary emboli. We report a case of an 18-year-old man who presented with spontaneous thrombosis of the deep cerebral veins and straight dural sinus as the initial presentation of a previously undiagnosed AT III deficiency. METHODS: The patient was managed using direct endovascular infusion of the fibrinolytic agent urokinase followed by intravenous heparin. RESULTS: The technique was successful in establishing patency of the deep cerebral venous system. The patient experienced a good clinical outcome. CONCLUSIONS: Direct endovascular thrombolysis is a potentially effective management strategy for isolated thrombosis of the deep cerebral venous system.

Adult↗
PubMed1997

Frameless stereotactic guidance for surgery of the upper cervical spine.

OBJECTIVE: The goal was to evaluate and describe the use of a frameless, computed tomography-guided, stereotactic technique in complex procedures involving the craniocervical junction. METHODS: Eleven procedures, including transoral odontoid resection, posterior atlantoaxial fusion with transarticular C1-C2 screw fixation, and spinal tumor resection, were performed in the preceding 26 months. In each case, frameless stereotaxy was used to plan the incision, to define resection margins, and to determine the appropriate orientation of instrumentation. RESULTS: There were no intraoperative complications noted. Each patient underwent adequate resection of the pathological lesion and satisfactory placement of instrumentation. The stereotactic system provided detailed anatomic visualization, which increased the confidence of the surgeon during the procedure. The system limited the need for extensive surgical exposure, reduced fluoroscopy time, and decreased the risk of neurovascular injury. CONCLUSION: Frameless stereotaxy provided the surgeon with intraoperative information regarding the extent of bone and soft tissue resection. It provided a multidimensional view of anatomic relationships in the operative field, which significantly increased surgical accuracy and safety.

Adult↗
PubMed1997

Evaluation with evoked and spontaneous electromyography during lumbar instrumentation: a prospective study.

The neuroanatomical structures that approximate the bony pedicles of the lumbar spine allow little room for technical error or compromise of the bone during pedicle screw insertion. Currently available neurophysiological monitoring techniques detect compromised bone and nerve root injury after it occurs. The purpose of this prospective study is to evaluate the reliability and efficacy of a unique neurophysiological monitoring technique. This technique provides immediate evaluation of pedicle cortical bone integrity in patients undergoing lumbar fusion with instrumentation by using electrified surgical instruments throughout the pedicle screw fusion procedure. Spontaneous electromyographic (EMG) activity was also monitored. Intraoperative evoked EMG stimulation was performed using a pedicle probe and feeler as monopolar stimulators during the insertion of 164 pedicle bone screws in 32 patients. The EMG response to subthreshold stimulation intensities indicated cortical bone compromise. Immediate and conclusive feedback via evoked EMG activity using stimulating pedicle probes in appropriate muscle groups was successful in identifying pedicle cortical bone compromise in four patients. One false-negative evoked EMG study was noted but was identified via spontaneous EMG activity. Intraoperative EMG monitoring alerted the surgeon that redirection of the pedicle probe or screw was necessary to avoid nerve root irritation or injury and served as an early warning system. Evoked EMG stimulation proved to be reliable and efficacious, especially when used in combination with spontaneous EMG. This technique may provide an added safeguard during implant placement procedures at centers where intraoperative neurophysiological monitoring is routinely performed.

Adult↗
PubMed1997

Endovascular thrombolysis in deep cerebral venous thrombosis.

We present two cases of acute thrombosis of the internal cerebral veins, vein of Galen, and straight sinus without sagittal sinus involvement. Both patients had hydrocephalus and severe edema of the basal ganglia and thalami, one with hemorrhagic infarction of the thalamus. Because both patients rapidly deteriorated to a comatose state, endovascular thrombolysis was performed with urokinase infusion of the deep venous structures. Thrombolysis was continued until a patent channel with brisk flow in the venous structures was achieved. Both patients survived with minimal neurologic deficits.

Adolescent↗
PubMed1997

Preliminary results of the use of a two-stage treadmill test as a clinical diagnostic tool in the differential diagnosis of lumbar spinal stenosis.

This study assesses the ability of a two-stage treadmill test to distinguish stenotic from nonstenotic subjects by capitalizing on the postural dependency of stenotic symptoms. Forty-five subjects (26 stenotic, 19 nonstenotic) participated. An earlier onset of symptoms with level walking (p = 0.0009), increased total walking time on an inclined treadmill (p = 0.014), and prolonged recovery time after level walking (p = 0.001) were significantly associated with stenosis. Only one of four self-reported postural variables were significantly associated with stenosis. Linear discriminant analysis performed using the treadmill variables resulted in the correct classification of 76.9 and 94.7% of stenotic and nonstenotic subjects, respectively. Likelihood ratios for all treadmill variables were > 2.50, and < 2.00 for all self-report variables. A two-stage treadmill test may be useful in the differential diagnosis of lumbar stenosis, and clinical measurement of the postural nature of symptoms seems to be superior to subjects' self-reports.

Adult↗
PubMed1996

Longitudinal atlantoaxial dislocation with type III odontoid fracture. Case report and review of the literature.

Odontoid fractures are a common traumatic upper cervical spine injury. Treatment of Type III odontoid fractures includes skeletal traction for realignment and halo vest immobilization. The authors report an unusual case of severe atlantoaxial ligamentous disruption accompanying a traumatic Type III odontoid fracture. Five pounds of skeletal traction was associated with marked neurological deterioration from unanticipated longitudinal instability. Radiographic findings were identified that were suggestive of extensive ligamentous disruption. Recommendations for individualized patient management are given in the context of related literature.

Adult↗
PubMed1995

Surgery for metastatic spinal disease.

Cancer is a leading cause of death in the United States. Despite the development of advanced treatment for many malignancies, a large number of patients will require evaluation and possible surgical intervention for lesions which have metastasized to or directly invaded the spinal column. The recommendations for operative intervention on these patients should be made following evaluations by multiple specialties, both medical and surgical. An improved understanding of the pathophysiology of malignancy and the development of advanced adjunctive treatment modalities have improved the quality and duration of life in many patients. Recent studies have demonstrated the utility of early surgery when combined with other treatment modalities. Surgical techniques for tumor resection and spine stabilization have improved the outcome of patients reported in multiple surgical series. A multidisciplinary approach to treatment of cancer patients with spinal involvement affords the patient an optimal outcome.

Aged↗
PubMed1995

Morphologic, immunologic, biochemical, and cytogenetic characteristics of the human glioblastoma-derived cell line, SNB-19.

Human glioma-derived cell cultures and lines have proven to be of significant value in the study of the basic properties that contribute to the highly malignant, invasive and angiogenic phenotype of glioblastoma multiforme tumors. It is frequently difficult to establish lines that retain glial tumor properties in long term culture. The SNB-19 cell line has maintained and exhibited properties of transformation, differentiation, autocrine growth response, and tumorigenesis while remaining in culture for over 13 yr and undergoing over 200 passages. This human line has been utilized in a wide range of studies related to the basic properties of human glioblastoma multiforme. In this report, we summarize the immunologic, biochemical, and cytogenetic properties of this versatile cell line and its utility for additional mechanistic investigation into the pathophysiology of the progression of human malignant gliomas.

Animals↗
PubMed1995

Isolated toxoplasmosis of the thoracic spinal cord in a patient with acquired immunodeficiency syndrome. Case report.

Toxoplasmosis and lymphoma are the two most common causes of intraparenchymal cerebral mass lesions in patients with acquired immunodeficiency syndrome (AIDS). The clinical and radiographic features of the intracranial lesions have been well described. Because of the high frequency of toxoplasmosis in the AIDS population, common therapy for patients presenting with intracranial mass lesions consists of an empirical trial of anti-Toxoplasma chemotherapy, with biopsy reserved for cases demonstrating features considered to be more consistent with lymphoma, or for lesions that do not improve despite adequate anti-Toxoplasma treatment. A similar treatment algorithm does not exist for intramedullary lesions of the spinal cord. The authors describe a patient who presented with paraparesis resulting from an isolated thoracic intramedullary lesion. An open biopsy of the lesion revealed characteristic structures containing Toxoplasma tachyzoites. The clinical and radiographic presentation of the lesion is discussed, the available literature is reviewed, and a treatment strategy for spinal cord lesions in AIDS patients is proposed.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Systemic malignancy presenting as neck and shoulder pain.

Systemic malignancy can be manifested by musculoskeletal complaints. We review the history, physical examination, and diagnostic imaging studies of a patient whose chief complaints were neck and shoulder pain. This patient also had significant weight loss and a history of tobacco abuse. Aggressive physical therapy and appropriate medications failed to provide symptomatic relief of neck and shoulder pain. Further studies revealed lung cancer. Systemic malignancy can cause referred musculoskeletal pain without obvious metastatic involvement at the symptomatic area, and should be considered in patients with persistent symptoms.

Cervical Vertebrae↗
PubMed1993

The future of therapy for glioblastoma.

Effective therapy for malignant gliomas has centered on traditional approaches such as surgery and radiation therapy. Over the past two decades, more innovative approaches involving the use of chemotherapy and immunotherapy have been developed. Although these techniques have improved the quality of survival for many patients, the median survival following diagnosis and adjuvant treatment still remains only about a year. Recently, genetically engineered viruses for gene transduction and targeted cell killing have been used successfully in the experimental treatment of glioblastoma multiforme. We provide a review of the current and possible future therapies for malignant glioma with the belief that molecular biologic and genetic techniques offer the greatest hope of significantly altering the course of disease.

Combined Modality Therapy↗
PubMed1988

Moyamoya disease in an infant with autonomic dysfunction: angiographic and MRI findings.

An infant with persistent Harlequinism went on to develop a hemiparesis secondary to Moyamoya disease at 2 1/2 months of age. The sympathetic nervous system is proposed to be an etiologic factor in the pathophysiology of Moyamoya disease as well as Harlequinism. This is one of the youngest patients reported in the English literature with Moyamoya disease and the only report of the coexistence of Moyamoya disease and atypical Harlequinism. Magnetic resonance imaging led to the diagnosis, which was confirmed by cerebral angiography.

Arterial Occlusive Diseases↗
PubMedDate not supplied

Relationship between type of health insurance and time to inpatient rehabilitation placement for surgical subspecialty patients.

A significant proportion of patients on a neurosurgical service require inpatient rehabilitation placement after discharge. The relationship between the type of health insurance of the patient at the time of admission and the time to placement of patients has not previously been addressed. We prospectively studied all patients on the adult neurosurgical service at our hospital to determine whether the type of health insurance carried by patients is related to the time necessary to arrange acceptance into inpatient rehabilitation facilities. Ninety-one patients (51 men, 40 women; mean age, 56 years) admitted to the neurosurgery service during a 6-month period required inpatient rehabilitation placement after discharge. The time in days between the request for placement into a rehabilitation facility and the acceptance of the patient was examined. The mean time for placement of patients with and without health insurance at the time of admission was 0.8 days and 2.1 days, respectively (overall mean, 1.1 days) (P < .002). No statistically significant associations were found between age, sex, or race of the patient and the time to placement. In addition, there was no difference in the time to placement between those patients admitted as a result of trauma and those patients admitted for reasons other than trauma. These results indicate that among patients on a neurosurgical service, patients with private health insurance are accepted into inpatient rehabilitation approximately 1 day sooner than patients without private health insurance. Patients without private health insurance are delayed in their transfer to inpatient rehabilitation facilities and more aggressive inpatient rehabilitation. How this finding translates into an increase in cost of care or a decrease in patient outcomes is unknown.

Adolescent↗
PubMedDate not supplied

Variability of intracellular concentrations of basic fibroblast growth factor in cultured human gliomas.

BACKGROUND: Basic fibroblast growth factor (bFGF) is a small peptide with angiogenic and mitogenic properties that supports the growth and proliteration of human malignant glial tumors in vitro and in vivo in an autocrine fashion. The purpose of this study was to examine the potential relationship between intracellular bFGF concentrations and grade of glial malignancy using a monolayer cell culture system. MATERIALS AND METHODS: Samples from 13 histopathologically verified astrocytic brain tumors and two non-tumorous astrocyte specimens were grown in tissue culture and examined both early and late after explantation together with a bFGF-producing reference cell line. RESULTS: Elevated intracellular concentrations of bFGF were noted in the reference line as well as two of five other glioblastoma multiforme-derived cell cultules, three of five anaplastic glioma-derived cell cultures, and two of three astrocytoma-derived cell cultures. The cells derived from non-tumorous astrocyte specimens expressed low concentrations of bFGF. CONCLUSION: This study demonstrates that overlap exists between the grade ot glial malignancy and intracellular bFGF levels.

Adult↗
PubMedDate not supplied

Hepatocyte growth factor (HGF) and receptor (c-met) in normal and malignant astrocytic cells.

BACKGROUND: Hepatocyte growth factor (HGF) is a multifunctional peptide that binds to a specific receptor, c-met. Both HGF and c-met have been identified in normal brain and on glial tumors. The purpose of this study is to further define the biologic importance of HGF and c-met on normal and malignant glial cells grown in vitro. MATERIALS AND METHODS: Nine human malignant glioma-derived tumor cell cultures and cultures of astrocytes derived from normal brain were examined for c-met and HGF transcripts using Northern blot or RT-PCR analysis. Cellular invasiveness was quantitated by mechanical assay and mitogenesis was determined by cell count. RESULTS: C-met was expressed in five of seven malignant glioma-derived tumor cell cultures and in both normal astrocyte cultures. HGF transcript was not detected in any of the cell cultures. HGF supplementation enhanced invasiveness in c-met positive cell lines and did not alter cellular mitogenesis in the assayed cultures. CONCLUSIONS: These findings suggest that HGF is a potent stimulator of invasiveness in c-met positive malignant glioma-derived tumor cells and is not an active cytokine with regards to in vitro glial cell proliferation. HGF may therefore stimulate glioma cellular invasion in vivo through binding to its receptor and by activating tyrosine kinase secondary messengers.

Adolescent↗