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M L Apuzzo

Publications and source records attributed to M L Apuzzo.

At least 73 records · Page 4Linked to original sources
PubMed1994

Magnetic resonance imaging and quantitative analysis of intracranial cystic lesions: surgical implication.

The authors evaluated a series of proven intracranial cystic lesions prospectively. The relative signal intensities of these lesions on both T1- and T2-weighted sequences were correlated with the composition and viscosity of the cystic contents. Specimens were collected from 51 patients by cyst aspiration or at the time of surgery. Once a specimen was obtained, it was immediately sent for quantitative analysis of proteins, cholesterol, triglyceride, calcium, and blood by-products. In 30 patients, the cystic lesion was hypointense on T1 and hyperintense on T2 relative to white matter. The cystic content in this group of patients was a watery fluid that could be easily aspirated. In another 14 patients, the cystic lesion was either isointense or hyperintense on T1 and hyperintense on T2-weighted sequences. In this group of patients, the cystic contents were mild to moderately viscous and a wide bore needle or cannula was required for aspiration. In the remaining seven patients, the cystic contents were hyperintense (n = 4), isointense (n = 2), or hypointense (n = 1) on T1 but all were markedly hypointense on T2-weighted sequences. The contents of the cystic lesions in these seven patients ranged from pastelike to solid and had to be removed surgically. This study concludes that the observed T1- and T2-weighted signal intensities can predict the relative viscosity and the composition of intracranial cystic contents. This information is found to be quite useful in planning surgery and using appropriate instrumentation in the management of intracranial cystic masses.

Adolescent↗
PubMed1994

Hypericin: a potential antiglioma therapy.

Hypericin, a polycyclic aromatic dione isolated from plants, is presently being clinically evaluated as an antiviral agent in the treatment of human immunodeficiency virus (HIV) infection. In addition, it is known to be a potent protein kinase C inhibitor. To evaluate its potential as an inhibitor of glioma growth, an established (U87) and low-passage glioma line (93-492) were treated with hypericin in tissue culture for a period of 48 hours after passage. Hypericin inhibited the glioma growth in a dose-related manner, with a marked inhibition of growth in the low-micromolar concentration range (e.g., in line U87 and low-passage line 93-492, a concentration of hypericin of 10 mumol/L produced 62 and 76% decreases in [3H]thymidine uptake, respectively). Because the reported inhibitory effects of protein kinase C are enhanced by visible light, [3H]thymidine uptake was measured in both the presence and the absence of visible light. In glioma line A172, the presence of light slightly increased the inhibitory effect of hypericin. Moreover, an apoptosis (i.e., programmed cell death) assay was performed to determine whether the treatment of glioma cells with hypericin was cytostatic or cytocidal. Cells were harvested, and purified deoxyribonucleic acid (DNA) was analyzed by agarose gel electrophoresis. DNA from cells treated with hypericin for 48 hours exhibited a classical "ladder" pattern of oligonucleosome-sized fragments characteristic of apoptosis. These data suggest that the proven safe drug hypericin may have potential as an antiglioma agent; we suggest clinical trials.

Anthracenes↗
PubMed1994

Cytokine expression in radiation-induced delayed cerebral injury.

Radiation-induced delayed brain injury is a well-documented complication of both standard external beam radiation (teletherapy) and interstitial brachytherapy; however, the cause of this damage has not been determined. Cytokines and growth factors are important regulatory proteins controlling the growth and differentiation of normal and malignant glial cells, which have been implicated in the tissue response to radiation injury. Six snap-frozen brain biopsies showing radiation injury were obtained from four patients harboring malignant gliomas who underwent either postoperative external beam and/or stereotactic interstitial brachytherapy at standard dosages. The specimens showed variable amounts of gliosis, tissue necrosis, calcification, inflammation, and vascular proliferation and hyalinization. Frozen tissue sections were examined for the presence of infiltrating lymphocytes, macrophages, cytokines, and other immunoregulatory molecules by the use of a panel of specific monoclonal and polyclonal antibodies. All specimens showed diffuse T cell infiltration with both CD4+ and CD8+ cells. Infiltrating activated macrophages (CD11c+, HLA-DR+) were prominent in five of six cases. Tumor necrosis factor-alpha and interleukin-6 immunoreactivity was prominent in four of six cases and was predominately localized to macrophages. Transforming growth factor-beta astrocytic and macrophage immunoreactivity was present at moderate levels in all cases. This study suggests that in radiation necrosis, interleukin-1 alpha, tumor necrosis factor-alpha, and interleukin-6 are expressed, predominately by infiltrating macrophages.

Adult↗
PubMed1994

Multifocal inflammatory leukoencephalopathy associated with levamisole and 5-fluorouracil: case report.

Levamisole and 5-fluorouracil have now become the standard chemotherapeutic regimen for patients with Stage III colon carcinoma. A case of multifocal inflammatory leukoencephalopathy secondary to levamisole alone or combination of levamisole and 5-fluorouracil is reported. Magnetic resonance imaging with gadolinium demonstrated multifocal contrast-enhancing frontal, parietal, occipital, and periventricular white matter lesions. A stereotactic biopsy revealed reactive gliosis and macrophage infiltration, without evidence of metastatic tumor. Despite continuation of 5-fluorouracil, resolution of contrast-enhancing lesions on magnetic resonance imaging without further neurological sequelae occurred when levamisole was stopped. The patient died with evidence of systemic metastasis 6 months later. Autopsy examination of the brain revealed multifocal demyelinating lesions, with no evidence of metastatic tumor. Immunoperoxidase studies of demyelinated lesions demonstrated infiltrating macrophages strongly positive for Class II antigens, interleukin-6, and interleukin-1 alpha. Surrounding astrocytes were positive for granulocyte macrophage colony-stimulating factor. Small numbers of perivascular T cells were present. This patient represents the first autopsy documented case of levamisole associated multifocal inflammatory leukoencephalopathy.

Aged↗
PubMed1994

Complex technical methodologies and their applications in the surgery of intracranial meningiomas.

As neurosurgery moves into the twenty-first century, improved visualization/localization techniques, neuromonitoring, and advanced instrumentation will become standards of care for all intracranial procedures. This article has focused on current available technologies that can be used to facilitate operations on intracranial meningiomas. Preoperative anatomic localization with MR imaging, CT, MR angiography, and angiography are standard techniques. Preoperative functional assessments with MR imaging, magnetic source imaging, PET, and functional MR imaging are crucial to recognize and preserve eloquent adjacent cortex. Pathologic correlations with preoperative imaging (i.e., MR imaging) may help to predict the histopathology. Perioperative rehearsal of the operation can be performed. Intraoperative anatomic localization is important to minimize the craniotomy, dural opening, and passage through normal neural structures. An impressive array of new technologies are currently available, including real-time ultrasonography, frame-based stereotaxy (CT, MR imaging PET), frameless stereotaxy (acoustic localization, neuronavigators, real-time visualization), robotics, neuroendoscopy, and intraoperative dye administration. Increased understanding of the function and individual variability of the human cortex underscores the importance of intraoperative functional localization by electrocorticography and optical imaging. Continuous intraoperative neuromonitoring of sensory (SSEPs, BAERs, visual evoked potentials) and motor evoked potentials is now standard during many intracranial procedures. Complex adjunctive instrumentation, such as the ultrasonic aspirator and the laser, are part of the contemporary armamentarium for meningioma surgery. As we have stated in a previous article, "Developmental trends imply realization of three major directions of technical neurosurgery: (1) precise preoperative simulation, (2) minimization or avoidance of transcranial operative corridors, [and] (3) increased refinement of technical adjuvants--both physical and molecular." The end point of these technical advances is to improve precision and safety and will enhance the outcome in each surgical procedure so that one day we will be able to operate on patients with intracranial lesions with minimal morbidity.

Brain↗
PubMed1993

Differential effects of tumor necrosis factor-alpha on proliferation, cell surface antigen expression, and cytokine interactions in malignant gliomas.

Tumor necrosis factor-alpha (TNF-alpha), a cytokine produced by astrocytes in vivo and in vitro, was tested for its effects on two malignant astrocytoma cell lines (A-172, U-87). Both lines were immunoreactive for glial fibrillary acidic protein, vimentin, Class I antigens, and interleukin-6. The lines differed in their expression of Class II and intercellular adhesion molecule-1 (ICAM-1) antigenic determinants: A-172 cells were negative for both Class II and ICAM-1 antigens, while U-87 cells were intensely positive for Class II and weakly positive for ICAM-1. When these astrocytoma cell lines were exposed to TNF-alpha, A-172 growth was stimulated while U-87 growth was inhibited. Furthermore, in U-87 cells, TNF-alpha enhanced both ICAM-1 and interleukin-1 beta (IL-1 beta) expression, and decreased immunoreactivity for transforming growth factor-beta (TGF-beta) protein. In contrast, in the presence of TNF-alpha, A-172 cells remained negative for IL-1 beta and TGF-beta, but showed an increased expression of ICAM-1. These results demonstrate that TNF-alpha can induce changes in growth rate, cytokine production, and surface antigen expression in malignant astrocytomas; however, the nature of these changes is dependent on the specific characteristics of these malignant astrocytomas. The resultant variability in the immunological microenvironment of these tumors may reflect differences in their growth potential.

Antigens, Neoplasm↗
PubMed1993

Stereotactic radiosurgery: principles and comparison of treatment methods.

Methods of stereotactic radiosurgery are reviewed and compared with respect to technical factors and published clinical results. Heavy-ion beams, the Leksell cobalt-60 gamma knife, and the conventional linear accelerator (linac) are compared with respect to dosimetry, radiobiology, treatment planning, cost, staffing requirements, and ease of use. Clinical results on the efficacy of treatment of arteriovenous malformations are tabulated, and other applications of radiosurgery are described. It is concluded that although there are dosimetric and radiobiological advantages to charged-particle beams that may ultimately prove critical in the application of radiosurgery to large (> 30 mm) lesions, these advantages have not yet demonstrated clinical effect. On the other hand, equally excellent clinical results are obtained for small lesions with photon beams--the gamma knife and the linac. There are only minor differences between gamma and x-ray beam dose distributions for small, spherical-shaped targets. Mechanical precision is superior for the gamma knife as compared with the linac. The superior mechanical precision is of limited importance for most clinical targets, because inaccuracy of cranial target localization based on radiological imaging is greater than the typical linac imprecision of +/- 1 mm. Treatment planning for the linac is not standardized, but existing systems are based on well-known algorithms. The linac allows flexible, ready access to individualized beam control, without intrinsic field size limitations. Thus, it is more readily possible to achieve homogeneous dose distributions for nonspherical targets with one or more dimensions greater than 25 mm, as compared with that achieved with the gamma unit.(ABSTRACT TRUNCATED AT 250 WORDS)

Equipment Design↗
PubMed1993

Clinical and radiographic response in a minority of patients with recurrent malignant gliomas treated with high-dose tamoxifen.

Previous work has demonstrated the importance of the Protein Kinase C (PKC) signal transduction system in regulating the growth rate of malignant gliomas in vitro. Tamoxifen inhibits PKC in a minority of malignant gliomas within the micromolar concentration range in vitro, a property distinct from its estrogen receptor blockade effect. Tamoxifen was administered orally in very high dosages to 11 patients (9 males:2 females, age range 26-73, mean 45 years) with malignant gliomas (anaplastic astrocytoma or glioblastoma multiforme) who had failed treatment with external beam radiation therapy (and additional chemotherapy in 2). The dosage administered was estimated to be that necessary to achieve tissue concentrations within the low micromolar range, shown necessary to inhibit PKC in these tumors in vitro, and is approximately 5 times that used for standard antiestrogen therapy. Tumor reduction on radiographic images (MRI and PET [18FdG uptake]) with clinical improvement occurred in 3 patients; halting of tumor progression clinically and radiographically occurred in an additional patient. Of the remaining seven patients, three patients had marked and rapid progression of their disease despite treatment (dead after 3, 4, and 6 months respectively). Complications of treatment included a deep venous thrombosis requiring anticoagulation in one patient, nausea in one patient, and "hot-flashes" in a third patient. Tumor biopsy and measurement of tamoxifen and its active metabolite within the tumor of one patient (non-responder) showed levels within the middle of the in vitro therapeutic range. Follow-up of alive patients ranges from 4-18 months (mean 10 months). These encouraging preliminary results in a minority of these patients suggests some potential for this type of therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

The significance of subarachnoid hemorrhage after penetrating craniocerebral injury: correlations with angiography and outcome in a civilian population.

Certain clinical factors are considered to have an effect on patient outcome after penetrating missile injury. These include bilateral hemispheric injury, ventricular hemorrhage, intracerebral hemorrhage, mass effect, and missile or bony fragmentation. The relationship of subarachnoid hemorrhage (SAH) after penetrating craniocerebral injury and outcome is unknown. In addition, controversy exists regarding the role of angiography and the incidence of traumatic intracranial aneurysm in this population. Finally, can we assume that the incidence of traumatic intracranial aneurysm is equal in military and civilian populations, given the absence of penetrating shrapnel injury in civilian populations? Now that computed tomography has supplanted angiography as the primary diagnostic modality, increasing vigilance on the part of the physician and examination of angiography in high-risk patients should allow for enhanced outcome. We evaluated 100 patients with a diagnosis of cerebral gunshot wound over a 12-month period. All patients were evaluated neurologically at the time of admission and had imaging studies. Thirty-one patients with radiological evidence of SAH on computed tomography underwent angiography. Angiograms were limited to the side of the injury in patients with single-lobe or unilateral multilobe injuries and were bilateral in patients with bilateral hemispheric involvement. One intracranial aneurysm (3.2%) was documented and treated surgically. In those patients who died within 48 hours of admission, 68% had SAH as compared with only 17% of those surviving. Outcome was based upon neurological evaluation at the time of discharge and at the time of clinical follow-up at 3 and 6 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Architecture and functional design of advanced neurosurgical operating environments.

Although modern operative neurosurgery is a complex technical undertaking requiring an amalgam of technologies and instrumentations, few reported efforts have dealt with the definition and development of suitable and optimal dedicated operating environments. This report presents the first detailed description of a dedicated, self-contained neurosurgical operating suite incorporating major surgical instrumentation and visualization technologies to provide an "idealized" environment for stereotactic, microscopic, and microstereotactic procedures. Advanced computer technology for visualization to augment, simulate, document, and facilitate all aspects of neurosurgery is described. The architectural and functional design of the operating suite is itself an integral surgical instrument as well as a laboratory for development of new dimensions of neurosurgery.

Computer Systems↗
PubMed1993

Hemangiopericytoma of the temporal bone presenting as a retroauricular mass.

An unusual case of a hemangiopericytoma arising from the temporal bone is presented. The patient was noted to have a postauricular mass and was neurologically asymptomatic. A preoperative magnetic resonance image and an angiogram revealed the tumor to be highly vascular. Preoperative embolization facilitated the surgical removal of the tumor by rendering it avascular. Current therapy consists of radical resection of the tumor with postoperative radiation therapy. Patients must be monitored carefully for local recurrence and systemic metastasis.

Adult↗
PubMed1993

Penetrating craniocerebral injury resultant from gunshot wounds: gang-related injury in children and adolescents.

We prospectively and retrospectively reviewed a series of 780 patients who presented to the University of Southern California/Los Angeles County Medical Center with a diagnosis of gunshot wound to the brain during an 8-year period. Of these, 105 were children ranging in age from 6 months to 17 years. Injuries were gang related in 76 (72%) children and adolescents. Stepwise linear regression analysis was used to formulate a predictive model of outcome in this population. Patient age (F = 10.92), sex (F = 9.32), occipital entry site (F = 8.17), bihemispheric injury (F = 8.50), and admission Glasgow Coma Scale (F = 69.91) were all found to correlate with outcome (P < 0.05). Significant differences between pediatric and adult populations were noted in transit time, entrance site, and age-related outcome. Occipital or assassination-type wounds were most common in children. In addition, a younger age was associated with poor outcome (P < 0.0001). We describe both the economic and racial trends in our population of patients in addition to weapon type and toxicological evaluation. The Department of Neurological Surgery is becoming directly involved in providing information to children at the junior high school level regarding gang activity and brain and spinal cord injury. In conjunction with the Community Youth Gang Services Organization and Think First Organization, we are attempting to integrate prevention through education and community mobilization. This is a plan aimed at informing and recovering the youth affected by gangs.

Adolescent↗
PubMed1992

Cystic fluid in craniopharyngiomas: MR imaging and quantitative analysis.

A prospective study of cystic fluid in craniopharyngiomas in 10 patients was performed to correlate signal intensity on T1-weighted magnetic resonance (MR) images and biochemical analysis. Within 2 days before surgery, each patient underwent MR imaging before and after administration of gadopentetate dimeglumine. Five patients had cystic fluid lower in signal intensity than white matter, with protein levels less than 9,000 mg/dL (90.00 g/L) and no free methemoglobin. One of the five patients had the highest triglyceride concentration (84 mg/dL [0.95 mmol/L]) of all 10 patients; another of these five had the highest cholesterol concentration of all (270 mg/dL [6.98 mmol/L]). It is concluded that the increased signal intensity of cystic fluid in craniopharyngiomas on T1-weighted MR images can be caused by a protein concentration greater than or equal to 9,000 mg/dL (90.00 g/L), the presence of free methemoglobin, or both. In the ranges of concentrations measured in this study, cholesterol and triglyceride did not increase signal intensity.

Adolescent↗
PubMed1992

Radionecrosis secondary to interstitial brachytherapy: correlation of magnetic resonance imaging and histopathology.

Radiation-induced tissue damage in the central nervous system is a well-known complication of interstitial brachytherapy for brain tumors, yet imaging correlates have historically been based upon computed tomographic scans. We now present magnetic resonance imaging (MRI) to correlate radiation changes after interstitial brachytherapy with the histopathology. The central nervous system of a 38-year-old man with a left frontal cerebral glioma diagnosed by stereotactic biopsy was treated with interstitial brachytherapy (iridium-192, 47 Gy), followed by limited-field irradiation (45 Gy). With progressive deterioration, a second biopsy demonstrated radiation changes. Despite aggressive medical management, the patient died 9 months after completion of radiation therapy. Postmortem evaluation compared MRI scans of the intact, fixed brain with the histopathology. Axial sections (10 mm) obtained by MRI scan and autopsy brain slices were cut in the identical plane. Neuroimaging and histopathological findings of the lesion correlated within 2 to 3 mm resolution. In the peripheral white matter, MRI scan did not indicate the extent of radiation effect histologically. We suggest that MRI has limited utility in assessing the extent of impact of radiation on surrounding brain.

Adult↗
PubMed1992

Magnetic resonance imaging and pathological correlates of meningiomas.

We examined the relationships between specific magnetic resonance imaging features and certain gross and microscopic characteristics of meningiomas, including vascularity, gross texture (consistency), and venous sinus involvement. Magnetic resonance imaging scans, surgery reports, and the histopathological findings of tumors were examined retrospectively in 54 patients. Sinus involvement was accurately predicted on T1-weighted images in 9 of 10 cases (P = 0.001) and tumors with cystic changes in 3 of 3 cases. T1-weighted images were not useful for predicting vascularity unless actual flow voids could be visualized (five of six cases). There was no correlation between T1 signal intensity, tumor consistency, or histological findings. In tumors without detectable vascularity on T1-weighted images, hyperintensity relative to gray matter on T2-weighted images was correlated with increased vascularity (P = 0.004). Tumors with soft consistency (P = 0.007), cellular atypia, invasion, angioblastic, or melanocytic components were also hyperintense, compared with gray matter on T2-weighted images (P = 0.0266). Aggressive meningiomas were found to be more vascular (P = 0.045). No correlation was found between the degree of surrounding edema or contrast enhancement with histopathological findings, vascularity, or consistency.

Brain↗
PubMed1992

Cytokines and immunoregulatory molecules in malignant glial neoplasms.

Cytokines are important regulatory proteins controlling growth and differentiation of normal and malignant glial cells. Astrocytes and microglial cells produce and respond to many of the same cytokines employed by cells of the immune system. The authors have analyzed 15 histologically confirmed malignant glial neoplasms for the presence of infiltrating lymphocytes, macrophages, cytokines, and other immunoregulatory molecules using a panel of specific monoclonal and polyclonal antibodies on frozen-tissue sections. All neoplasms showed focal T-cell infiltration with CD8 cells predominating. Infiltration of activated macrophages (positive for CD11c, class II, and interleukin-2 receptor) was marked in all tumors. Within the neoplasm, tumor necrosis factor-alpha (TNF-alpha)- and interleukin (IL)-6-positive macrophages were prominent in five cases, while the tumor cells themselves were only weakly positive. In the other 10 cases, the numerous infiltrating macrophages were only rarely immunoreactive for TNF-alpha or IL-6. Transforming growth factor-beta (TGF-beta) immunoreactivity was most prominent in those tumors with little TNF-alpha-positive macrophage infiltration, although intratumoral variability was present. This study suggests that, in malignant gliomas, the cytokines TNF-alpha and IL-6, although weakly present in neoplastic cells, are most prominent in infiltrating macrophages and in those regions of the tumors that show little immunoreactivity for TGF-beta. The important interactions among neoplastic, reactive glial, and inflammatory cells, which regulate tumor growth, are likely to be in part mediated through these molecules.

Adult↗
PubMed1992

Cysticercosis cerebri.

With increasing immigration from endemic regions, the incidence of cysticercosis in North America is rising. This fascinating disease with its varied presentations may pose complex management dilemmas whose resolutions often require a combined approach to treatment involving medical and, in some cases, selected surgical intervention. The treatment course must be individualized depending on the symptomatology, anatomic location of the cysts, and host inflammatory response.

Brain↗