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Biomedical subjects

M L Apuzzo

Publications and source records attributed to M L Apuzzo.

At least 91 records · Page 5Linked to original sources

Surgical strategies and technical methodologies in optimal management of craniopharyngioma and masses affecting the third ventricular chamber.

Management of craniopharyngiomas and masses affecting the third ventricular chamber represents one of the most challenging problems confronting contemporary neurological surgeons. Given the devastating sequelae of surgical complications involved in approaches to the deep cerebral midline, surgical management requires a combination of sophisticated imaging, diagnostic pathology and surgical technique including ventricular microsurgery and stereotaxy and its attendant refinements. Surgical and non-surgical management is based upon the structural presentation of these masses as defined by detailed imaging studies. Operative objectives include histological definition, maximally feasible excision, cerebral spinal fluid diversion and relief of neurologic deficits created by masses affecting the third ventricular chamber.

Cerebral Ventricle Neoplasms↗

Malignant glioma modulation of immune function: relative contribution of different soluble factors.

We analyzed a series of human glioma cell lines with regard to establishing what variables may contribute to their overall functional immunomodulating capability. We observed that supernatants derived from the gliomas, but not those from non-malignant human astrocyte cultures, suppressed lymphocyte proliferation. The extent of suppression elicited differed between tumors and for the same tumor depending upon its growth phase. For individual gliomas, supernatants from cultures approaching or at confluency elicited maximal lymphocyte suppression. For the series of tumors, levels of production of the immunosuppressive molecules transforming growth factor beta 2 and prostanoids (prostaglandin E2) did not correlate with the levels of functional suppression observed at any of the different growth phases. In some cases, glioma cultures grown in the presence of indomethacin to abolish prostanoid synthesis resulted in supernatants with net stimulatory activity. Our results indicate that malignant transformation of astrocytes is associated with acquisition of immunosuppressive capability which is determined by the combined effect of multiple immunomodulatory soluble factors, inhibitory or enhancing, and is dependent on the growth phase of the tumor.

Dinoprostone↗

Treatment results of stereotactic interstitial brachytherapy for primary and metastatic brain tumors.

A total of 41 stereotactic interstitial brain implants in 39 patients were performed for recurrence after teletherapy (recurrence implant), or as part of initial treatment in conjunction with teletherapy (primary implant). Implanted tumors consisted of malignant gliomas (33), other primary brain tumors (3), and single metastatic lesions (3). All patients were temporarily implanted with Ir-192 using a coaxial catheter afterloading system; two patients were implanted twice. Survival post-implant for glioblastoma multiforme (GBM), 13 patients, was 10 months whether implanted primarily or for recurrence. Mean time to recurrence, measured from initiation of teletherapy to implantation, was 10 months. Twenty patients with anaplastic astrocytoma (AA) had a median survival post-implant of 23 months for primary implants (7 patients) and 11 months for recurrence implants (13 patients). Mean time to recurrence, measured from initiation of teletherapy to implantation, was 19 months. Three patients (9%) of the evaluable group required reoperation for symptomatic mass effect, all with initial diagnosis of AA. Survival for this subgroup was 14, 22, and 32 months post-implantation. Using stereotactic techniques, interstitial brachytherapy of brain tumors was technically feasible with negligible acute morbidity and mortality, and appeared to offer limited prolongation of control for a subset of patients with recurrent malignant gliomas. The role of this modality in primary treatment for malignant gliomas needs to be further defined by prospectively randomized trials.

Adolescent↗

Definition of the role of contemporary surgical management in cisternal and parenchymatous cysticercosis cerebri.

With increasing immigration from endemic regions, the incidence of neurocysticercosis in North America is rising. This retrospective study was undertaken to examine the role of surgery in those cases presenting with large cystic parenchymal and cisternal lesions in the current era of anthelminthic agents administered orally. A total of 237 patients presented with newly diagnosed neurocysticercosis to our institution over a recent 5-year period (mean age, 31.2 years). Among those who presented with cystic mass lesions predominantly affecting the brain parenchyma and cisternal spaces, 20 (8.4%; mean age, 40.2 years) with large cystic lesions subsequently underwent surgical intervention, either because of an emergent presentation or because they were refractory to medical management. Clinical presentation included increased intracranial pressure, focal neurological deficit, and seizure. Radiographic imaging (computed tomography and/or magnetic resonance imaging) demonstrated 12 cases with cisternal lesions, 7 with parenchymal lesions, and 1 involving both compartments. Based on imaging guidelines, 30 operative procedures (excluding shunt revisions) were performed (14 craniotomies, 8 cerebrospinal fluid diversions, 7 stereotactic procedures, and 1 burr hole drainage). Fifteen (75%) showed neurological or symptomatic improvement over a median follow-up period of 36.4 months. There were three surgery-related complications and no deaths.

Adult↗

Adrenal to caudate transplantation--postmortem study.

A patient with Parkinson's disease who had undergone bilateral adrenal to caudate implantation by stereotactic technique came to autopsy. The implantation was shown to have produced minimal trauma and to have been well placed. Minimal surviving adrenal medullary tissue remained in the implanted coil, and no outgrowth of tissue into the striatum occurred.

Adrenal Medulla↗

Technique of left adrenalectomy for autotransplantation to the caudate nucleus in Parkinson's disease.

Autotransplantation of the adrenal medulla to the caudate nucleus is a new neurosurgical treatment under investigation for severe Parkinson's disease. The success of the procedure is reliant partly on the ability of the urologist to remove the adrenal gland safely and atraumatically with minimal morbidity. We describe our technique using a posterior 12th rib approach, which is extrapleural and extraperitoneal. In the initial 10 patients there was no significant morbidity from the operation and all patients were discharged from the hospital within 3 to 7 days postoperatively. The importance of using a no touch technique in mobilizing the gland is emphasized, since any hemorrhage within the adrenal medulla may make it impossible to recover the tissue for stereotactic implantation. Hemorrhage occurred in 1 of our patients, who was elderly and obese. The technique described allows for adequate exposure while maintaining acceptably low morbidity from the procedure.

Adrenal Medulla↗

Utilization of unilateral and bilateral stereotactically placed adrenomedullary-striatal autografts in parkinsonian humans: rationale, techniques, and observations.

A limited clinical pilot study involving an amalgam of specialized disciplines including neurology, neuropharmacology, neuropsychology, neurosurgery, neuroanesthesia, neuroradiology, surgical pathology, neuropathology, and urological surgery was organized to clarify issues related to patient selection, optimization of grafting materials, design of a safe, effective, standardized, and reproducible surgical technique, and possible modification of clinical patterns. After initial assessment of 82 Parkinsonian patients for periods of 6 to 20 months, 10 (age, 39-68 years) were selected for unilateral or bilateral adrenomedullary autografts to the caudate nucleus with ependymal and cerebrospinal fluid contact, employing image-directed stereotactic methods. Selection was made only after clear definition of clinical pattern and optimization of medication responses. Adrenal glands were harvested by a retroperitoneal approach (mean estimated blood loss less than 75 ml). Care was taken to maximize the graft content of medullary tissue. Stereotactic methods afforded standardized, reproducible, precise targeting and transit trajectory with unilateral or bilateral placement of materials within the striatum (tissue volume, 80 mm3) with access to the ventricular fluid of the frontal horn. Considerable variability in satisfactory donor medullary tissue was encountered. One patient did not undergo grafting because of unsatisfactory medullary tissue. No significant surgical complications were noted and all patients were ready for discharge 7 days after surgery. One patient who manifested no apparent clinical change died 6 weeks after bilateral grafting of unrelated causes during a lithotripsy procedure. Postmortem examination disclosed precise graft placement with a paucity of structurally preserved medullary cells. Postoperative observations, including parameters of clinical observation, medication schedules and records, patient and family commentaries, and imaging studies (computed tomograms and single photon emission computed tomograms), have been made for periods from 16 to 20 months. Sustained improvement in preexisting clinical patterns and reduction in drug requirements were observed in 4 of 8 patients. No increased benefit could be ascribed to bilateral graft placement. These observations would indicate a safe, and reproducible surgical method. In addition, the clinical observations indicate favorable alterations in the established pattern of the disorder, which would justify further cautious exploration of alternate donor sources or refinements of biological graft site manipulations.

Adrenal Medulla↗

Initial experience related to the use of the Cosman-Roberts-Wells stereotactic instrument. Technical note.

Initial experience with a new arc-radius design of stereotactic frame that interfaced with the existing components of the Brown-Roberts-Wells instrument is reported. Over a 6-month period, 32 procedures were performed on 23 males and nine female patients (mean age 32 years); these included 27 stereotactic biopsy procedures, two stereotactic implantations of cyst catheter reservoirs, two ventriculoscopic aspirations of third ventricular colloid cysts, and one stereotactic aspiration of a craniopharyngioma. In all cases successful targeting was achieved and verified by postoperative computerized tomography. There were no operation-related complications. This new frame offers rapid and accurate targeting and is a useful adjunct to the stereotactic armamentarium.

Adult↗

Inhibition of growth of established human glioma cell lines by modulators of the protein kinase-C system.

The protein kinase-C (PKC) second messenger system contributes to regulation of cell growth and differentiation. This study was undertaken to examine the effects of modulators of the PKC enzyme system on the state of differentiation and proliferation rates of human gliomas in vitro. The administration of the PKC-activating phorbol esters 4-beta-phorbol-12,13-dibutyrate (PDB) and phorbol-12-myristate-13-acetate (PMA) resulted in a dose-related inhibition of growth of human glioma cell lines in vitro as measured by 3H-thymidine uptake. The synthetic nonphorbol PKC activator (SC-9) produced an even more pronounced decrease of 3H-thymidine uptake. Diacylglycerol, an endogenous activator of the system, applied externally, transiently decreased the proliferation, in concordance with its short-lived existence in vivo. Conversely, the administration of 4-alpha-phorbol-12,13-didecanoate (alpha-PDD), a phorbol ester that binds but does not activate the enzyme, had no effect on the proliferation rate. At the dosages that maximally decreased proliferation, there was no evidence of direct glioma cell lysis induced by these agents as measured by a chromium-release assay. Immunocytochemical analysis and cytofluorometric measurement of glial fibrillary acidic protein (GFAP) staining in the treated cultures revealed an increase in GFAP staining over control cultures. In contrast to the response of glioma cells, nonmalignant human adult astrocytes treated with the PKC activators responded by increasing their proliferation rate. The authors postulate that the diametrically opposed effects of PKC activators on nonmalignant astrocytes versus glioma growth may be due to a high intrinsic PKC activity in glioma cells, with resultant down-regulation of enzyme activity following the administration of the pharmacological activators.

Astrocytes↗

Multiparameter flow cytometric analysis of neoplasms of the central nervous system: correlation of nuclear antigen p105 and DNA content with clinical behavior.

Analysis of the DNA content of various solid tumors and hematological malignancies may provide useful prognostic information. To date, however, there has been a striking lack of correlation between DNA content in neoplasms of the central nervous system and clinical behavior. Simultaneous quantitation of DNA content and proliferation-associated nuclear antigen (p105) by flow cytometry was performed on paraffin-embedded tissues representing three major groups of central nervous system neoplasms--1) 21 astrocytic tumors, 2) 13 pituitary tumors, and 3) 19 meningiomas--and the results were correlated with clinical behavior. All 4 well-differentiated gliomas were diploid, while 3 of 9 anaplastic astrocytomas and 1 of 8 glioblastomas had a demonstrable aneuploid peak. Three of 13 pituitary tumors had an identifiable aneuploid peak, while only 2 of 19 meningiomas had an aneuploid DNA content. Cell-cycle analysis of the malignant gliomas revealed a significantly higher proliferative index (PI, %S + G2M) compared with the well-differentiated astrocytomas (P less than 0.05). Within the subgroup of diploid anaplastic astrocytomas, however, extended patient survival appeared to be associated with a higher PI. For diploid pituitary adenomas, the PI was consistently lower in the 3 tumors that recurred than it was in the remaining 8 adenomas. Nuclear antigen quantitation of diploid tumors showed a wide range of p105 expression in G0G1 cells, suggesting that, within each tumor, the cells are heterogeneous with respect to proliferative activity. Aneuploid nuclei of glial tumors showed enhanced expression of p105 relative to diploid cells of the same specimen. In pituitary tumors, the median G2M/G0G1 fluorescence ratio for p105 was significantly higher (P less than 0.05) for the 3 diploid recurrent tumors than for those that did not recur. These data support the assumption that the aggressive clinical course of malignant glial neoplasms may be related to an abnormal DNA stemline and/or an alteration in cell proliferative activity. Cell cycle analysis and measurement of p105 by this technique may provide information useful from both a prognostic standpoint and in directing adjuvant therapy.

Adult↗

Stereotactic biopsy in the diagnosis of brain masses: comparison of results of biopsy and resected surgical specimen.

We report the pathological accuracy of image-directed stereotactic brain biopsy in 30 patients who had mass lesions of the brain and subsequently underwent resection of the mass. The histological diagnosis at stereotactic biopsy was appropriate for direction of clinical management in 28 of 30 patients. Correlation between the stereotactic and resection diagnoses was exact in 19 of 30 cases. These included 11 of 12 nonastrocytic neoplasms and 8 of 13 astrocytic neoplasms. Correlation was imperfect in 9 of 30 cases, but not to the extent of having significant clinical impact. These included 2 cases of anaplastic astrocytoma that were upgraded to glioblastoma multiforme, 2 cases of astrocytoma that had a significant oligodendroglial component, and 5 non-neoplastic lesions that were reported on biopsy as showing nonspecific reactive changes. In 2 of 30 patients, the stereotactic biopsy was not accurate. This included one patient who had glioblastoma multiforme whose stereotactic biopsy showed only necrotic tissue. Serious diagnostic error that resulted in clinical mismanagement occurred in one patient who had a pineal germinoma that had large areas of granulomatous inflammation at which the stereotactic biopsy was directed. This study provides evidence that, with careful target placement, stereotactic biopsy can provide biopsy material that represents the entire lesion with an accuracy that is sufficient for clinical management.

Astrocytoma↗

Flow cytometric analysis of pituitary tumors. Correlation of nuclear antigen p105 and DNA content with clinical behavior.

Flow cytometric quantitation of the proliferation-associated nuclear antigen p105 and DNA content was performed on nuclear suspensions from 12 paraffin-embedded pituitary macroadenomas and one pituitary carcinoma and correlated with clinical outcome. Median follow-up was 41 months (range, 33 to 48 months). Three of the 13 tumors (23%) had an identifiable aneuploid peak. Of the four tumors that recurred or metastasized, only one was aneuploid. Nuclear antigen analysis of all diploid tumors showed enhanced p105 expression in G2M phase cells compared to G0G1 cells. The G2M/G0G1 fluorescence ratio for p105 was consistently higher (P less than 0.05) for the three diploid tumors that recurred (median, 1.32 arbitrary fluorescence units; range, 1.27 to 1.80) than for the seven nonrecurrent diploid tumors (median, 1.20 arbitrary fluorescent units; range 1.14 to 1.22). These findings indicate a low incidence of DNA aneuploidy among pituitary tumors and suggest that for diploid adenomas, measurement of p105 may provide information useful in predicting prognosis and directing postoperative adjuvant therapy.

Adolescent↗

Flow cytometric DNA and nuclear antigen content in astrocytic neoplasms.

Simultaneous flow cytometric DNA content and proliferation-associated nuclear antigen (p105) quantitation was performed on 23 astrocytic tumors and the results correlated with histologic subtype. Three of nine anaplastic astrocytomas and one of ten glioblastomas had an identifiable aneuploid peak, while all four well differentiated astrocytomas were diploid. Cell cycle analysis of malignant gliomas revealed a higher mean percentage of S and G2M cells compared to well differentiated astrocytomas but there was considerable overlap between histologic subtypes. Nuclear antigen analysis of diploid tumors showed a higher mean p105 fluorescence of S + G2M cells than G0G1 cells from the same case but there were no apparent differences in p105 expression by histologic subtype. Aneuploid tumors showed enhanced expression of p105 relative to diploid cells. The findings suggest that the aggressive course of high grade glial tumors may be related to an abnormal DNA stemline or an increase in proliferative activity.

Antigens, Neoplasm↗

Photoradiation therapy and its potential in the management of neurological tumors.

Photoradiation therapy is a form of local treatment that depends on the selective retention of a photosensitizer, such as hematoporphyrin derivative (HpD), by the tumor followed by treatment with light of an appropriate wavelength to activate the sensitizer in the tumor. The selective uptake of HpD by cerebral tumors has been demonstrated both in laboratory animal model studies and in clinical studies, and selective destruction of intracerebral tumors has been demonstrated in animal glioma models. The biological basis for photoradiation therapy and, in particular, the mechanisms for the selective uptake of the sensitizer into the tumor and the destruction of tumor with photoradiation therapy are discussed. Current evidence suggests that singlet oxygen is the major intermediary leading to cell damage, although other radicals such as hydrogen peroxide and hydroxyl radicals may be involved. Other studies suggest that the initial damage is to the blood vessels, and the tumor subsequently undergoes ischemic changes. Sixty-four patients treated with photoradiation therapy have been reported in the literature. The initial clinical studies were disappointing in their therapeutic effect but these studies often included treatment of recurrent gliomas and low doses of light were used. Technical advances, particularly in laser technology, have enabled more effective photoradiation therapy and the clinical trials are reviewed.

Adolescent↗